E T O S FEBRUARY TH 2019 - DKTK · Targeting cancer stem cells and immune escape ... Functional analysis of CD30 in Hodgkin and anaplastic large cell lymphoma cell lines by CRISPR/Cas9-mediated

2ND

ESSEN TRANSLATIONAL ONCOLOGY SYMPOSIUM FEBRUARY 7TH, 2019

2nd ESSEN TRANSLATONAL ONCOLOGY SYMPOSIUM, FEBRUARY 7th, 2019 - 1 -

CONTENT

OVERVIEW TALKS AND POSTERS .................................................................................................................... 1

OVERVIEW TALKS ........................................................................................................................................ 1

OVERVIEW POSTERS in DKTK PROGRAM ORDER ........................................................................................ 3

ABSTRACTS

Abstracts for Talks T1 – T19 .......................................................................................................................... 11

Abstracts for POSTERS ................................................................................................................................... 31

EXPLOITATION OF ONCOGENIC MECHANISMS ..................................................................................... 32

RADIATION ONCOLOGY AND IMAGING ................................................................................................ 51

CLINICAL COMMUNICATION PLATFORM .............................................................................................. 59

MOLECULAR DIAGNOSTICS, EARLY DETECTION AND BIOMARKER DEVELOPMENT ............................. 60

MOLECULARLY TARGETED THERAPY ..................................................................................................... 75

CANCER GENOME SEQUENCING AND PROTEOME ANALYSIS ............................................................... 88

CANCER IMMUNOTHERAPY .................................................................................................................. 91

Floor Plan ....................................................................................................................................................... 99

INDEX PRESENTERS...................................................................................................................................... 101

Editorial Responsibility: Sabine Kaul DKTK Administrative Coordinator [email protected]

Edited by: German Cancer Consortium (DKTK) German Cancer Research Center (DKFZ) DKTK Partner Site Essen/Düsseldorf University Hospital Essen Hufelandstrasse 55 47147 Essen The texts originate from the individual research groups. Images on cover: GLIPH: DKTK Translational Skin Cancer Research Group; Jürgen C. Becker Stairway: UK Essen (Kittel)


OVERVIEW TALKS AND POSTERS

OVERVIEW TALKS (Seminar room 0.0019)

Presenter Title and Key Words Department Nbr.

Wiesweg, Marcel

Machine Learning Models for Outcome Prediction of Immune Checkpoint Inhibitor Therapy in Non-Small Cell Lung Cancer

Key words: Lung cancer, immunotherapy, PD-L1, machine learning

Department of Medical Oncology (Essen)

T1

Spassova, Ivelina

Predominance of terminally differentiated T cells among tumor infiltrating lymphocytes impair response to PD-1/PD-L1 inhibition in Merkel cell carcinoma

Key words: Merkel cell carcinoma, immune checkpoint inhibition, biomarker, T-cell differentiation

DKTK Division of Translational Skin Cancer (Essen)

T2

Müberra, Ahci-Hanci

HLA immune escape by leukemia relapse increases with immunologic pressure of cellular immunotherapy

Key words: Immune Escape, HLA, stem cell transplantation, leukemia, NGS

Institute of Experimental Cellular Therapy (Essen)

T3

Dierichs, Laura

Acquired MEKi Resistance in Pancreatic Cancer is Associated with DNA Hypermethylation and Increased Sensitivity to DNMTi

Key words: PDAC, Acquired Therapy Resistance, DNA Methylation, DNMTi

DKTK Division of Solid Tumor Translational Oncology (Essen)

T4

Dorsch, Madeleine

Multiplexed in vivo small molecule screening for immediate drug repositioning reveals novel therapeutic targets in metastatic pancreatic cancer

Key words: PDAC, metastasis, in vivo screening, mouse models


T5

Shannan, Batool

Sequence-dependent cross-resistance of combined radiotherapy plus BRAFV600E-inhibition in melanoma

Key words: Melanoma, radiotherapy, targeted therapy, resistance, therapy sequencing.

Department of Dermatology (Essen)

T6

Nothdurft, Silke

Identification of novel metastasis-modulating factors in non-small-cell lung cancer

Key words: Non-small-cell lung cancer, metastasis, orthotopic lung cancer mouse model, shRNA screen, RNA-Seq


T7

Chauvistré, Heike

Overcoming tumor plasticity by chemically enforced phenotype homogenization as a new therapeutic strategy in melanoma

Key words: Melanoma, heterogeneity, plasticity, resistance, JARID1B/KDM5B


T8

Brandau, Sven

Quantitative in situ high resolution analysis of human cancer tissue provides evidence for MDSC activity of tumor-associated neutrophils

Key words: head and neck cancer, neutrophils, MDSC, digital pathology, tumor microenvironment

Department of Otorhinolaryngology (Essen)

T9

Franken, André

Circulating Tumor Cells from Cryo-Conserved Leukapheresis Product can be Used for In Vitro Culture

Key words: Diagnostic leukapheresis, CTC culture, cryo-conservation

Department of Obstetrics and Gynaecology (Düsseldorf)

T10


TALKS (seminar room 0.0019)

Presenter Title and Key Words Department Nbr.

Bartl, Jasmin

HHIP-AS1 PROMOTES TUMOR SURVIVAL THROUGH STABILIZING DYNEIN COMPLEX 1 IN HEDGEHOG DRIVEN HUMAN BRAIN TUMORS

Key words: Sonic Hedgehog Pathway, ATRT, Medulloblastoma, long non coding RNA

DKTK Division of Pediatric Neuro-Oncogenomics (Düsseldorf)

T11

Rösch, Alexander Introduction of the DFG KFO 337 PhenoTImE Department of Dermatology (Essen)

T12

Fendler, Wolfgang

PSMA-PET DETECTS M1 DISEASE IN MORE THAN HALF OF A “NONMETASTATIC” CASTRATION-RESISTANT PROSTATE CANCER SPARTAN-LIKE POPULATION

Key words: CRPC, PSMA, prostate, cancer, PET

Department of Nuclear Medicine (Essen)

T13

Bäumer, Christian

Motion effects in proton treatments of hepatocellular carcinoma- Interplay in 4D robustly optimized pencil beam scanning plans

Key words: proton therapy, pencil-beam scanning, HCC, robust optimization

Department of Particle Therapy (Essen)

T14

Matschke, Johann

Targeting antioxidant-associated mitochondrial carboxylate (mCB) transport systems to increase cancer cell radiosensitivity in the context of acute and chronic hypoxia

Key words: Chronic cycling hypoxia, Radiation resistance, Metabolic reprogramming, Antioxidant capacity, DNA repair

Institute of Cell Biology (Cancer Research) (Essen)

T15

Seifert, Marc

The analysis of clonally related sibling cells to monitor transformation and developmental dynamics in CLL

Key words: CLL, clonal development, tumor monitoring


T16

Langer, Samantha

Unravelling the molecular mechanisms of mutant RUNX1 in MDS stem cells

Key words: MDS, RUNX1, mouse model, essential targets

Institute of Transfusion Medicine (Essen)

T17

Barbeau, L. and Bazarna, A.

Mechanism of metastasis and vulnerabilities of BAP1-mutant tumors

Key words: ccRCC, BAP1, metastasis, microRNAs, synthetic lethality

DKTK Division of Translational Genomics in Solid Tumors (Essen)

T18

Lu, I-Na

Profiling immune cell types in glioblastoma using transcriptomes

Key words: Glioblastoma, Systems Immunology, Machine Learning, Hematopoietic Progenitors, Immunotherapy

DKTK Division of Translational Neurooncology (Essen)

T19


OVERVIEW POSTERS in DKTK PROGRAM ORDER

POSTERS EXPLOITATION OF ONCOGENIC MECHANISMS (MAIN FLOOR)

Presenter Title and Key Words Department Poster Nbr.

Aretz, Philippe

Targeting cancer stem cells and immune escape mechanisms in Glioblastoma by inhibition of canonical Wnt/β-catenin-signaling

Key words: WNT, CCL2, Glioblastoma, onco-immunology, targeted therapy

Department of Neurosurgery (Düsseldorf)

EOM P1

Bordbari, Shareh

The regulatory effect of Type I IFNs on neutrophil angiogenic capability in tumor microenvironment

Key words: IFNb, Tuomr-associated neutrophils, pro-tumor and anti-tumor neutrophils, tumor vascularization


EOM P2

Cull, Alyssa

Precise Modeling of Deletions in Myelodysplastic Syndromes and Acute Myeloid Leukemia

Key words: MDS, AML, tumor suppressors, model system, stem cells


EOM P3

Hassiepen, Christina

The role of the neurotrophin receptors, TrkA/NTRK1 and TrkB/NTRK2, in modulation of the radiation response of cancer cells

Key words: TrkA/NTRK1, TrkB/NTRK2, Neuroblastoma, Radiation, Oncology

Department of Medical Oncology(Essen)

EOM P4

Lange, Erik

Impact of the gut microbiota on colorectal cancer and immunotherapy

Key words: colorectal cancer, microbiome, immunotherapy, antibiotics

Institute of Medical Microbiology (Essen)

EOM P5

Lollies, Anna

Molecular Mechanisms in the Pathogenesis of Composite Lymphomas

Key words: Composite Lymphomas, Pathogenesis, Whole exome sequencing


EOM P6

Ludescher, Marina

PGRMC1 Promotes Tumor Progression of Breast Cancer via Up-Regulation of ERα Expression

Key words: PGRMC1, breast cancer, estrogen receptor α, EGFR


EOM P7

Mairinger, Elena

Fibroblast activating protein expression is strongly associated with desmoplastic stromal reaction in different human cancers and may serve as radio-therapeutical target

Key words: FAP, biomarkers, radiopharmaceutical target

Institute of Pathology (Essen)

EOM P8

Patil, Ashwini

The cellular cross-talk between emerging T cell acute lymphoblastic leukemia and thymic epithelial cells is mediated via the CXCL10/CXCR3 axis

Key words: T cell acute lymphoblastic leukemia (T-ALL), thymic epithelial cells (TEC), CXCL10

Department of Hematology (Essen)

EOM P9

Placke, Jan-Malte

Proteomic landscape analysis in ICB-treated melanomas – preliminary results

Key words: Melanoma, Immune checkpoint blockade, CD8 TIL, MALDI-Imaging


EOM P10


Siakaeva, Elena

Antigen presenting properties of neutrophils during HNC tumor progression

Key words: neutrophils, cancer, lymph nodes, antigen presentation


EOM P11

POSTERS EXPLOITATION OF ONCOGENIC MECHANISMS (Main Floor)


Stamm, Nadia

PGRMC1 Interacts with Enzymes of the Cholesterol Biosynthesis Pathway resulting in altered cholesterol metabolism and enhanced proliferation of breast cancer cells

Key words: PGRMC1, breast cancer, ERα, cholesterol biosynthesis


EOM P12

Tsiampali, Nerantzoula

The role of CD73 in glioblastoma growth

Key words: GBM, ZEB1, CD73, Pentoxifylline


EOM P13

Ullrich, Vivien

Prospective analysis of tumor subclones in recurrent glioblastoma

Key words: Glioblastoma, Heterogeneity, Subclones, Drug resistance

DKTK Division of Translational Neurooncology (Essen)

EOM P14

Vega Rubin de Celis, Silvia

Breast tumorigenesis regulation by autophagy and HER2

Key words: Autophagy, breast cancer, Beclin 1, HER2


EOM P15

Weiß, Annika

Functional analysis of CD30 in Hodgkin and anaplastic large cell lymphoma cell lines by CRISPR/Cas9-mediated gene knockout

Key words: CRISPR/Cas9, lymphoma, CD30


EOM P16

Wessolly, Michael

Processing escapes: Induction of therapy resistance by altered proteasomal epitope processing

Key words: Proteasomal processing, epitopes, immune-checkpoint inhibition, machine learning, explorative data analysis


EOM P17

Wossidlo, Natalie

Modeling MDS- associated Mybl2 haploinsufficiency in mouse HSPCs in vitro

Key words: MDS, Mybl2, haploinsufficient tumor suppressor, in vitro model


EOM P18

Yusuf, Suad

Investigating reciprocal regulations of nutrient starvation of glioblastoma stem-like cells

Key words: Glioblastoma, t, WNT, starvation, metabolism


EOM P19


POSTERS RADIATION ONCOLOGY AND IMAGING (Main Floor)


Thumser-Henner, Clothilde

Syntaxin 18 (STX18) is a novel modulator of the radiation response in non-small cell lung cancer (NSCLC)

Key words: Non-small cell lung cancer, syntaxin 18, radiotherapy, targeted therapy


ROI P1

Nagaraja, Sindhu

Proton therapy for base of skull tumors at West German Proton Therapy Center Essen (WPE)

Key words: Proton Therapy, Base of skull tumors, sarcomas, central nervous system, head and neck


ROI P2

Peters, Sarah

Proton Beam Therapy (PT) for brain tumors in childhood at WPE

Key words: brain tumor , childhood cancer, proton therapy


ROI P3

Rudner, Justine

Anti-malaria Drug Dihydroartemisinine Improves Radiotherapy

Key words: Dihydroartemisinine, radiotherapy, glutathione, reactive oxygen species


ROI P4

Staniszewska, Magdalena

Combined Androgen Receptor and DNA damage response inhibition to enhance prostate-specific membrane antigen-directed radioligand therapy of prostate cancer

Key words: mCRPC, PSMA, prostate, cancer, PET

Department of Nuclear Medicine (Essen)

ROI P5

Szymonowicz, Klaudia

comparison of the cellular response of DNA repair-deficient cells to photon and proton irradiation in vitro

Key words: Proton irradiation, SOBP, Photon irradiation, DNA repair deficiency, clonogenic survival


ROI P6

Jazmati, Danny

The impact of radiotherapy for metastatic bone lesions in neuroblastoma.

Key words: neuroblastoma, metastases, irradiation


ROI P7

Verbeek, Nico

Towards high-precision dose calculations for proton therapy

Key words: PENELOPE, PENH, Monte Carlo, proton


ROI P8

POSTERS CLINICAL COMMUNICATION PLATFORM

(MAIN FLOOR)


Asperger, H. and Cieslik, J.

Development of a browser-based sample bank for multicenter liquid biopsy trials

Key words: Liquid Biopsy, virtual sample bank, translational research


CCP P1


POSTERS MOLECULAR DIAGNOSTICS, EARLY DETECTION AND

BIOMARKER DEVELOPMENT (Main Floor)


Ahmadov, Ulvi

The long non-coding RNA HOTAIRM1 mediates radioresistance in glioblastoma

Key words: Glioblastoma, long non-coding RNAs, HOTAIRM1, radiation


MDEB P1

Arjmand Abbassi, Y.

Genetic testing exonerates the majority from the risk present in only a few: Differential diagnosis of BAP1 Cancer Syndrome in patients with uveal melanoma

Key words: heritable predisposition, Uveal Melanoma, BAP1

Department of Ophthalmology (Essen)

MDEB P2

Blümel, Lena

Targeting primary ciliogenesis in atypical teratoid/rhabdoid tumors

Key words: AT/RT, primary cilia, targeted therapy


MDEB P3

Borchert, Sabrina

Characterizing the impact of metallothionein expression on sensitivity to platin compounds in malignant pleural mesothelioma cell lines – Knock-down of gene expression as new therapeutic approach?

Key words: cisplatin resistance, malignant pleural mesothelioma, siRNA, metallothioneins


MDEB P4

Ho, Cassandra

Patient-derived lung cancer cell models for prediction of individual therapy response

Key words: Patient-derived xenograft, NSCLC, lung cancer, ALK


MDEB P5

Langini, Maike

Investigating the role of MALAT1, a long non-coding RNA, in glioblastoma tumorigenesis

Key words: glioblastoma, MALAT1, long non-coding RNA, mass spectrometry


MDEB P6

Lohmann, Dietmar

Heritable predisposition to gastrointestinal stromal tumors: strategies for risk prediction by molecular genetic testing

Key words: Molecular pathology, heritable predisposition, incomplete penetrance

Department of Ophthalmology (Essen)

MDEB P7

Marquardt, Viktoria

HDAC and NFκB antagonists synergistically inhibit growth of MYC-driven medulloblastoma

Key words: MYC-driven medulloblastoma, drug screening, HDAC inhibitor


MDEB P8

Varaljai, Renata ctDNA-based therapy monitoring in melanoma patients

Key words: ctDNA, liquid biopsy, melanoma


MDEB P9

Qin, Nan

Cellular heterogeneity drives aggressive tumorigenesis in MYC-driven medulloblastoma

Key words: Medulloblastoma, MYC, Heterogeneity, Secretome


MDEB P10

Schmeller, Jan

Parallel progression of primary colorectal tumors and metastases

Key words: NGS; Molecular Pathology, Colon Carcinoma, Metastasis


MDEB P11


POSTERS MOLECULAR DIAGNOSTICS, EARLY DETECTION AND

BIOMARKER DEVELOPMENT (MAIN FLOOR)


Taban, Kübra

Identification of novel therapeutic approaches for medulloblastoma

Key words: Medulloblastoma, high-throughput drug screening (HTS)


MDEB P12

Temming, Petra

The Impact of the type of Predisposing RB1 Variants on incidence of Malignancies

Key words: tumor predisposition, retinoblastoma, sarcoma, RB1

Department of Pediatric Hematology and Oncology (Essen)

MDEB P13

Picard, Daniel

Proteogenomics reveals distinct biological pilocytic astrocytoma subgroups

Key words: Proteogenomics, Pilocytic Astrocytoma, Oncology


MDEB P14

Wiesweg, Marcel

Impact of RAS mutation subtype on clinical outcome – A cross-entity comparison of patients with advanced non-small cell lung cancer and colorectal cancer

Key words: Lung Cancer, colorectal cancer, RAS, BRAF


MDEB P15

POSTERS MOLECULARLY TARGETED THERAPY (1st Floor)


Ahlert, Heinz

The clinical relevance of indirect MYC inhibitors for personalized T-ALL treatment

Key words: T-ALL, Targeted Therapy, High Throughput Drug Screen, MYC, PTEN

Department of Pediatric Oncology, Hematology, and Clinical Immunology (Essen)

MTT P1

Lang, Franziska

Functional Characterization of the Ubiquitin-Proteasome-System in Pancreatic Ductal Adenocarcinoma

Key words: Ubiquitin-Proteasome System, Pancreatic Ductal Adenocarcinoma, CRISPR Cas9, Knock out screen


MTT P2

Hegedus, Luca

In newly established malignant pleural effusion derived anaplastic thyroid cancer cell line PD-L1 expression is strongly increased by HDAC inhibitor treatment

Key words: Anaplastic thyroid cancer, BRAF mutation, immune checkpoint, HDAC inhibition, pleural effusion

Department of Thoracic Surgery (Essen)

MTT P3

Kahmann, Karlotta

Pharmacologic LSD1 inhibition preserves human granulocytic

while expanding monocytic progenitors

Key words:


MTT P4

Karakaya, Sinan

Metabolic profiling and targeting of Pancreatic Ductal Adenocarcinoma

Key words: PDAC, metabolism, cancer, onco-metabolites


MTT P5


POSTERS MOLECULARLY TARGETED THERAPY (1ST FLOOR)


Borchert, Sabrina

Cisplatin induces CMGC kinases in platin-sensitive MPM cell lines: new therapeutic options for a severe disease?

Key words: cisplatin resistance, malignant pleural mesothelioma, kinase activity


MTT P6

Liffers, Sven-T.

Comprehensive molecular characterization of a pancreatic cancer PDX cohort for subtype-specific therapy approaches

Key words: PDAC, Subtype, PDX


MTT P7

Mairinger, Fabian Dominik

Bortezomib sensitivity is tissue dependant and high expression of the 20S proteasome precludes good response in malignant pleural mesothelioma

Key words: proteasome, pleural mesothelioma, mRNA expression, therapy


MTT P8

Mairinger, Elena

Tumor cell cytoplasmic metallothionein expression associates with differential tumor immunogenicity and prognostic outcome in high grade serous ovarian carcinoma (HGSOC)

Key words: metallothionein, ovarian cancer, biomarkers, immune system


MTT P9

Mergener, Svenja

Epigenetic Targeting in Patient-Derived Organoids from Uveal Melanoma and Clear-Cell Renal Cell Carcinoma

Key words: Uveal Melanoma, Clear-Cell Renal Cell Carcinoma, Organoids, Epigenetics, Drug Screening Experiments

DKTK Division of Translational Genomics in Solid Tumors (Essen)

MTT P10

Naser, Eyad

A role for acid ceramidase in hematopoietic stem and progenitor cellmobilization

Key words: -

Institute of Molecular Biology (Essen)

MTT P11

Ueffing, Kristina

Mitochondria dysfunction in metastatic lung adenocarcinoma: a progression specific therapeutic target

Key words: Lung cancer, metastasis, mouse models, mitochondria, pooled lentiviral-shRNA library screen


MTT P12

Zegar, Tim

GENERATION AND DEVELOPMENT OF A NOVEL DUAL BET/HDAC INHIBITOR WITH PROMISING ANTI-TUMOR PROPERTIES

Key words: epigenetics, BETi, HDACi, dual inhibitor


MTT P13


POSTERS CANCER GENOME SEQUENCING AND PROTEOME ANALYSIS

(2nd Floor)


Forster, Jan

Microphaser – Small scale phasing for neoantigen discovery

Key words: phasing, cancer immunotherapy, precision oncology

Institute of Human Genetics (Essen)

CGPA P1

Köster, Johannes

A latent variable model for structural variant

calling in tumor/normal sample pairs

Key words: somatic variant calling, tumor genomes, sequencing, Bayesian statistics


CGPA P2

Köster, Johannes Reproducible data analysis with Snakemake

Key words: data analysis, bioinformatics


CGPA P3


POSTERS CANCER IMMUNOTHERAPY (2ND FLOOR)


Crivello, Pietro

HLA-DM modulates the susceptibility of leukemia to CD4+ T cell alloreactivity in cellular therapy

Key words: CLIP, leukemia, HLA-DP, stem cell transplantation, T cell alloreactivity

Institute of Experimental Cellular Therapy (Essen)

CIT P1

Gravemeyer, Jan

Epigenetic profiling distinguishes variant MCC cell lines from classical MCC

Key words: MCC, microRNA, gene expression, methylation, EMT


CIT P2

Obholzer, Martin

Ovarian cancer immunotherapy by antibody-nanoparticle conjugates and natural killer cell activation

Key words: Ovarian Cancer, Nanoparticle, ADCC, NK cells


CIT P3

Peiffer, Lukas

BRAF/MEK inhibitor treatment causes altered TCR repertoire usage of tumor-infiltrating lymphocytes in melanoma

Key words: Melanoma, BRAF/MEK inhibition, adaptive immune response, TCR repertoire


CIT P4

Song, Lina

Domatinostat increases apoptosis, G2M cell cycle arrest and immunogenicity of Merkel cell carcinoma

Key words: MCC/skin cancers ; Antigen presentation ; Histone deacetylase inhibitor ; Cell cycle arrest


CIT P5

Szlachetko, Jagoda

Functional interplay in the tumor microenvironment: cross-talk between neutrophils, tumor cells and tumor-associated stromal cells.

Key words: Tumor microenvironment, neutrophils, mesenchymal stromal cells, extracellular vesicles


CIT P6

Thier, Beatrice

IFN-dependent bystander killing of melanoma cells by CD8+ T cells and mechanisms of resistance

Key words: IFN, CD8+ T cells, melanoma, bystander killing, resistance


CIT P7

Zhao, Fang

Combined HLA class I and HLA class II genotype alterations in melanoma from patients with primary and acquired resistance to immune checkpoint blockade

Key words: melanoma, HLA haplotype loss, resistance to immune checkpoint blockade, tumor escape, T cells


CIT P8


Abstracts for Talks T1 – T19


CANCER IMMUNOTHERAPY CLINICAL STUDIES

Machine Learning Models for Outcome Prediction of Immune Checkpoint Inhibitor Therapy in Non-Small Cell Lung Cancer

Marcel Wiesweg, Fabian Mairinger, Henning Reis, Moritz Goetz, Robert F. H. Walter, Thomas Hager, Martin Metzenmacher, Wilfried E. E. Eberhardt, Angela McCutcheon, Johannes Köster, Martin Stuschke, Clemens Aigner, Kaid Darwiche, Kurt W. Schmid, Sven Rahmann, Martin Schuler

Introduction:

Immunotherapy (ITx) targeting PD-1/PD-L1 is a standard of care in the treatment of stage IV NSCLC. However, only a minority of patients responds to ITx monotherapy. These can be only partially enriched by established predictive biomarkers.

Methods:

Patients with metastatic NSCLC treated with ITx were sequentially enrolled to a training (n=55) and validation cohort (n=36). Expression analysis of 770 immune-related genes was performed on the NanoString nCounter platform. Predictive feature sets were selected by ensemble-based penalized regression techniques and by utilizing previously published signatures of immune cell subtypes. Best performing machine learning techniques and associated hyperparameters were selected by cross-validation from a set of state-of-the-art algorithms.

Results:

Prediction models trained on best response following ITx in the training cohort successfully identified all “top responders” in the validation cohort. Concordant prediction of clinical benefit by these models identified a subgroup of patients that benefits from ITx (p=0.035, HR=0.32). PD-L1 expression provided complementary information and allowed forming finer predictive categories (favorable/intermediate/unfavorable, p=0.006).

Conclusions:

Machine learning techniques based on nCounter RNA expression data can be applied to achieve ITx response prediction. Pending further validation, its integration into a standard diagnostic workflow relying on small biopsy specimens is feasible.

For further information please contact: Marcel Wiesweg ([email protected])

Department of Medical Oncology, University Hospital Essen, University Duisburg-Essen

Seminar room 0.019 Key words: Lung cancer, immunotherapy, PD-L1, machine learning

Talk Nbr. T1


CANCER IMMUNOTHERAPY EX VIVO STUDIES / CORRELATIVE

SCIENCE

Predominance of terminally differentiated T cells among tumor infiltrating lymphocytes impair response to PD-1/PD-L1 inhibition in

Merkel cell carcinoma

Ivelina Spassova, Selma Ugurel, David Schrama, Daniel Hoffmann, Dirk Schadendorf, Jürgen C. Becker

Introduction:

Merkel cell carcinoma (MCC) is a rare, highly malignant skin cancer known for its high rate of metastasis and disease-related death. Recently, PD-1/PD-L1 checkpoint inhibition was recognized as an efficient treatment option for hitherto poorly manageable advanced metastatic patients. However, a significant proportion of patients demonstrate primary treatment resistance, and predictive biomarkers of treatment response are not established.

Materials and Methods:

Phenotyping of the immune infiltrate in MCC tissue was done by multiplexed immunofluorescence staining before and under treatment (n=15 patients). Additionally, T-cell receptor clonotype mapping and gene expression analysis of 720 immune-related genes of MCC bulk tumor were performed.

Results:

The molecular immune profiling of baseline tumor tissue revealed a high density of tumor-infiltrating CD8+ T cells and CD68+ macrophages in patients responding to PD-1/PD-L1 blockade. However, intratumoral frequencies of CD4+ T cells and FoxP3+ regulatory T cells showed no association with response. In contrast, baseline tumor tissues from responders revealed a lower T-cell clonality, but a higher T-cell receptor diversity as compared to non-responders. Moreover, tumor tissue from responders demonstrated a high expression of genes involved in T-cell activation and cytolytic function, and contained a T-cell infiltrate enriched by central memory T cells, whereas in non-responders, this infiltrate was predominated by terminally differentiated effector T cells.

Conclusion:

This explorative study identified a variety of new clinical and molecular baseline characteristics associated with response to anti-PD-1/PD-L1 therapy in MCC, which demand further evaluation as predictive markers in large patient cohorts.

For further information please contact: Ivelina Spassova ([email protected])

Translational Skin Cancer Research, University Hospital Essen,

Seminar room 0.019 Key words: Merkel cell carcinoma, immune checkpoint inhibition, biomarker, T-cell differentiation

Talk Nbr. T2


CANCER IMMUNOTHERAPY PRECLINICAL MODELS

HLA immune escape by leukemia relapse increases with immunologic pressure of cellular immunotherapy

Luca Vago, Cristina Toffalori, Müberra Ahci-Hanci, Vinzenz Lange, Kathrin Lang, Amin Turki, Sonia Todaro, Karin Stempelmann, Andreas Heinold, Friedrich Stölzel, Miguel Waterhouse, Rainer Claus, Ketevan Gendzekhadze, Masahiro Onozawa, Rayner Devillier, Ruoping Tang, Maayan Ulman, Dejan Lazarevic, Maria Teresa Lupo Stanghellini, Jacopo Peccatori, Nina Kristin Steckel, Peter A. Horn, Alessandra Picardi, Sara Manetta, Jose Luis Pinana, Jaimie Sanz, Brian Schaffer, William Arcese, Guillermo Sanz, Benedetto Bruno, Masimo Pini, Guido Kobbe, Katharine C. Hsu, Monzr Al Malki, Takanori Teshima, Nicolaus Kröger, Jurgen Finke, Arnon Nagler, Didier Blaise, Mohamad Mohty, Martin Bornhäuser, Dietrich W. Beelen, Alexander Schmidt, Fabio Ciceri, Katharina Fleischhauer

Introduction:

The clinical success of cancer immunotherapy is hampered by tumor immune escape, whose biological mechanisms are incompletely understood. Genomic loss of the patient-specific HLA (HLA loss) is frequently found in leukemia relapse after haploidentical hematopoietic stem cell transplantation (SCT). Here we investigated if HLA loss relapse is associated with the degree of histocompatibility and therefore immunologic pressure of the graft.


27 transplant centers from across the globe (Germany 5, Rest of Europe 17, Outside Europe 5) joined to collect genomic DNA from 324 patients with acute leukemias or other myeloid neoplasms at relapse after allogeneic SCT. SCT were from adult donors mismatched for a full HLA haplotype (haploidentical), 1-2 HLA-A,B,C,DRB1,DQB1 alleles (MMUD), HLA-DPB1 only (MUD), or from umbilical cord blood (UCB) mismatched for 1-4 HLA-A,B,C,DRB1,DQB1 alleles. Analysis was performed on a novel next-generation-sequencing (NGS) platform for quantification of HLA allele reads by direct counting, with a sensitivity of <1%.

Results:

In 324 cases of post-transplantation relapse after haploidentical (n=138), MMUD (n=92), 10/10-matched, HLA-DPB1 mismatched MUD (n=81), or UCB (n=13) SCT, the incidence of HLA loss was 25.5%, 11.5%, 3.8% and 0%, respectively. Correlation of these results with the clinical patient data is ongoing.

Conclusion:

The incidence of HLA loss relapse increases with genetic donor-recipient disparity in the adult volunteer donor setting. The absence of HLA loss relapse after UCB transplantation, despite the presence of increased numbers of HLA mismatches, is suggestive of new genetic mechanisms and has potential clinical implications.

For further information please contact: Müberra Ahci-Hanci ([email protected])

Experimental Cellular Therapy, bProf. Fleischhauer , University Hospital Essen

Seminar room 0.019 Key words: Immune Escape, HLA, stem cell transplantation, leukemia, NGS

Talk Nbr. T3


MOLECULARLY TARGETED THERAPY PRECLINICAL MODELS

Acquired MEKi Resistance in Pancreatic Cancer is Associated with DNA Hypermethylation and Increased Sensitivity to DNMTi

Dierichs L., Forster J., Schröder C.; Liffers S-T., Behrens D., Rahmann S., Zeschnigk M., Siveke J.T.

Introduction:

Pancreatic ductal adenocarcinoma (PDAC) is amongst the most aggressive tumor entities with a poor 5-year survival rate <8 %. It is marked by extraordinary resistance to conventional therapies as chemotherapy or radiation and essentially all targeted therapies evaluated so far.


To address the role of DNA methylation and transcriptomic activity in acquired therapy resistance, we applied a trametinib-treated (MEKi) in vitro resistance model of genetically engineered mouse-based PDAC. We used whole-genome bisulfite and RNA sequencing for characterization of global methylation patterns and transcriptional dynamics together with functional analysis.

Results:

Acquired trametinib-resistance is accompanied by a phenotypic switch revealed by enriched EMT expression signatures leading to less differentiated cells. Surprisingly, step-wise reversibility occurs upon drug withdrawal. Trametinib-resistant cells display an increased vulnerability to decitabine (DNMTi) in accordance with differentially methylated regions (DMRs), mainly hypermethylated and located far from CpG-islands affecting transcription factor binding sites. Furthermore, we defined DMRs whose occurrence and loss are associated with MEKi-sensitivity.

Conclusion:

Our data indicate dynamic DNA methylation changes in the development and maintenance of trametinib-resistant phenotypes. We demonstrate that DNMTi acts as a ´re-sensitizer´ in MEKi-resistant PDAC.

For further information please contact: Laura Dierichs ([email protected])

Translationale Onkologie Solider Tumore, University Hospital Essen

Seminar room 0.019 Key words: PDAC, Acquired Therapy Resistance, DNA Methylation, DNMTi

Talk Nbr. T4



Multiplexed in vivo small molecule screening for immediate drug repositioning reveals novel therapeutic targets in metastatic pancreatic

cancer

Madeleine Dorsch, Kristina Ueffing, Christopher J. Schulze, Alexander Schramm, Martin Schuler, Jens T. Siveke, Monte M. Winslow, & Barbara M. Grüner

Introduction:

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease in which early occurring metastasis and its consequences to the patient are the primary cause of cancer deaths. Aim of this study is to apply a newly established multiplexed in vivo screening platform to screen two libraries for inhibitors of metastatic seeding in PDAC to identify novel therapeutic targets in an immediate drug repositioning approach.


We applied a multiplexed small molecule in vivo screening platform for identifying novel regulators of PDAC metastatic seeding in immunocompetent mice. This approach integrates molecular cell barcoding, in vitro compound pretreatment and in vivo selection to allow multiplexed compound screening in mice.

Results:

Using the established platform, we screened the FDA-approved inhibitor and the ICCB bioactive molecules libraries. The initial screen and dose-dependent secondary screen identified 5 top compounds with a specific yet so far unknown effect on metastatic seeding in vivo. Complementary in vitro assays confirmed their minor effects on overall tumor cell viability. Validation in vivo should lead to the most promising compound.

Conclusion:

We identified 5 top compounds that reduce PDAC metastatic seeding by using the multiplexed in vivo screening platform. We performed various in vitro assays to characterize these compounds in PDAC. Now, we validated the top five compounds in vivo for their application in treatment of metastatic PDAC.

For further information please contact: Madeleine Dorsch ([email protected])

WTZ Forschung/Innere Klinik, Molekulare Tumorpathologie , University Hospital Essen

Seminar room 0.019 Key words: PDAC, metastasis, in vivo screening, mouse models

Talk Nbr. T5



Sequence-dependent cross-resistance of combined radiotherapy plus BRAFV600E-inhibition in melanoma

B Shannan, J Matschke, H Chauvistre, F Vogel, D Klein, F Meier, D Westphal, J Bruns, R Rauschenberg, J Utikal, A Forschner, C Berking, P Terheyden, E Dabrowski, R Gutzmer, D Rafei-Shamsabadi, F Meiss, L Heinzerling, L Zimmer, R Varaljai, A Hoewner, S Horn, J Klode, M Stuschke, B Scheffler, A Marchetto, G Sannino, T.G.P. Grünewald, D Schadendorf, V Jendrossek, A Roesch

Introduction:

Treatment of patients with metastatic melanoma is hampered by drug-resistance and often requires combination with radiotherapy as last-resort option. However, also after radiotherapy clinical relapses are common. Here, we identified the H3K4 demethylase JARID1B/KDM5B as cellular marker for cross-resistance between BRAFV600E inhibition and radiotherapy.


Cell culture-based assays as well as animal experiments were used to analyze JARID1B expression following combined sequential treatment. Human melanoma brain tissues were stained for JARID1B expression, and stage IV melanoma patient data provided information on intracranial responses following combined sequential therapy.

Results:

JARID1Bhigh cells appeared more frequently in vitro and in vivo under upfront BRAFV600E inhibition followed by radiation as compared to the reverse sequence. Accordingly, retrospective follow-up data from irradiated melanoma brain metastases showed a reduced response of MAPKi-pretreated compared to MAPKi-naïve metastases. JARID1B favors cell survival by transcriptional regulation of genes controlling cell cycle, DNA repair, and cell death.

Conclusion:

JARID1B may represent a therapy-overarching resistance marker that could guide future therapy sequencing or represent a therapeutic target itself to overcome resistance.

For further information please contact: Batool Shannan ([email protected])

Department of Dermatology, AG Roesch, University Hospital Essen

Seminar room 0.019 Key words: Melanoma, radiotherapy, targeted therapy, resistance, therapy sequencing.

Talk Nbr. T6


MOLECULARLY TARGETED THERAPY EX VIVO STUDIES / CORRELATIVE

SCIENCE

Identification of novel metastasis-modulating factors in non-small-cell lung cancer

S. Nothdurft, F. Breitenbücher, R.A. Okimoto, B.M. Grüner, M. Hölzel, J. Forster, S. Kalmbach, A. Schramm, M. Schuler

Introduction:

Lung cancer is the leading cause of cancer-related deaths worldwide. Approximately 85% of lung cancer patients are diagnosed with non-small-cell lung cancer (NSCLC). Early stage NSCLC is treated by curative surgery, still many patients develop lymphatic and/or systemic metastases eventually leading to an unfavorable patient outcome. Adjuvant cisplatin-based chemotherapy and radiation only moderately reduce the risk of metastatic relapse. Hence, there is a high need for novel therapies for treatment and prevention of metastases.


In order to identify new potential therapeutic targets, we performed a functional in vivo shRNA screen in an orthotopic NSCLC mouse model. Next generation sequencing was used to identify barcoded shRNAs with significantly different representation between primary tumors and metastases. Prioritized shRNAs targeting candidate genes were introduced into human NSCLC NCI-H1975 cells by lentiviral transduction.

Results:

Specific shRNA clones differentially represented between primary tumors and metastases were found to modulate invasive and migratory capacity of H1975 cells in vitro. Further, shRNA-mediated suppression of one target gene was confirmed to have metastasis modulating properties in vivo using an orthothopic NSCLC model. Currently, results from an RNA sequencing experiment are analyzed in order to identify molecular mechanisms explaining the metastasis-modulating effects observed in vitro and in vivo.

Conclusion:

Putative metastasis-modulating factors in NSCLC were identified using a legit in vivo mouse model of lung cancer. The clinical relevance is to be determined by correlation studies in cohorts of patient with resected NSCLC from our institutional biobank.

For further information please contact: Silke Nothdurft ([email protected])

Innere Klinik (Tumorforschung), Laboratory for Molecular Oncology, , University Hospital Essen

Seminar room 0.019 Key words: Non-small-cell lung cancer, metastasis, orthotopic lung cancer mouse model, shRNA screen, RNA-Seq

Talk Nbr. T7



Overcoming tumor plasticity by chemically enforced phenotype homogenization as a new therapeutic strategy in melanoma

H. Chauvistré, S. Daignault, B. Shannan, D. Picard, C. Krepler, R. Ju, F. Vogel, L. Kubat, I. Spassova, F. Kaschani, S. Ninck, A. Sechi, O. Keminer, S. Stehbens, S. Löffek, Q. Liu, X. Yin, K. Jeyakumar, R. Varaljai, S. Gul, S. Rahmann, S. Horn, M. Ehrmann, A. Paschen, J. Becker, I. Helfrich, M. Remke, D. Rauh, M. Kaiser, N. K. Haass, M. Herlyn, D. Schadendorf and A. Roesch

Phenotypic heterogeneity and plasticity represent major drivers of tumor relapse in melanoma. Expression of the H3K4 demethylase and pRB-binding protein JARID1B/KDM5B follows a dynamic continuum across melanoma cells. Highly JARID1B-expressing cells are enriched after short-term drug treatment. However, under persistent drug-exposure, JARID1B heterogeneity is reconstituted. Using a doxycycline-titratable system and a novel chemical enhancer of JARID1B-expression, we found that JARID1Bhigh cells are transiently 'pseudo-differentiated'. Melanoma cells use this JARID1Bhigh growth-arrested state to survive drugs, but must decrease JARID1B expression again to re-enter cell cycling for long-term tumor repopulation. Overcoming the reversion to phenotypic heterogeneity by exogenous homogenization of the JARID1Bhigh phenotype causes tumor growth arrest, also in MAPKi-resistant melanoma. Mechanistically, JARID1B represents an integral checkpoint for coordinating cell differentiation via transcriptional control, stabilization of hypophosphorylated pRB, and attenuation of cytokinetic abscission. Thus, the plasticity among tumor differentiation states per se represents a novel therapeutic target, which can be chemically overcome.

For further information please contact: Heike Chauvistré ([email protected])

Department of Dermatology, AG Rösch, University Hospital Essen

Seminar room 0.019 Key words: Melanoma, heterogeneity, plasticity, resistance, JARID1B/KDM5B

Talk Nbr. T8


MOLECULAR DIAGNOSTICS, EARLY DETECTION AND BIOMARKER DEVELOPMENT

EX VIVO STUDIES / CORRELATIVE SCIENCE

Quantitative in situ high resolution analysis of human cancer tissue provides evidence for MDSC activity of tumor-associated neutrophils

Yu Si*, Simon Merz*, Philipp Jansen*, Stephan Lang, Matthias Gunzer, Joachim Klode, Anthony Squire, Sven Brandau

Introduction:

A high intratumoral frequency of neutrophils is associated with poor clinical outcome in most cancer entities. It is hypothesized that the acquisition of immunosuppressive MDSC (myeloid-derived suppressor cell) activity by neutrophils contributes to this effect. However, the evidence for such in situ MDSC activity is scarce. We sought to obtain evidence for this process.

Methods:

In addition to conventional 2-D multi-parameter immunofluorescence, we utilized a whole-mount tissue processing and staining procedure together with 3-D digital image reconstruction for in situ analysis of potential MDSC-T cell interactions. Quantitative image analysis was used to determine localization, density and functional status of neutrophils and T cells.

Results:

By quantifying the three-dimensional spatial distribution of both cell types, we identified intratumoral hot spots of high PMN-MDSC and T cell density. In these areas the frequency of cytotoxic and proliferative T cells was strongly reduced, especially if T cells were in close proximity or conjugated to PMN-MDSC expressing LOX-1 or Arginase I. Head and neck cancer patients with evidence for strong downregulation of T cell activity by PMN-MDSC presented with a significantly impaired survival.

Conclusion:

Our study is the first to identify distinct intratumoral areas of clinically relevant functional interaction between PMN-MDSC and T cells in patients with cancer.

For further information please contact: Sven Brandau ([email protected]),

Department of Otorhinolaryngology, University of Duisburg-Essen, University Hospital Essen

Seminar room 0.019 Key words: head and neck cancer, neutrophils, MDSC, digital pathology, tumor microenvironment

Talk Nbr. T9

mailto:[email protected]




Circulating Tumor Cells from Cryo-Conserved Leukapheresis Product can be Used for In Vitro Culture

André Franken1, Christiane Driemel2, Dieter Niederacher1, Nikolas H. Stoecklein2, Johannes C. Fischer3, Tanja Fehm1, Hans Neubauer1

Solid tumors are constantly releasing circulating tumor cells (CTCs) into the circulatory system. Their extremely low frequency is one of the main limiting factors to obtain CTCs for functional studies. To overcome this challenge CTCs are enriched prior to culturing from larger blood volumes or diagnostic leukapheresis (DLA) products. Nonetheless, only few patients with growing CTCs are obtained. However, it is critical to collect larger cohorts for further understanding of the biology of CTCs. Therefore, we tested to grow CTCs from banked cryo-conserved DLA products.

Materials and Methods: DLA samples of metastasized breast cancer patients were collected and CTC numbers were determined by CellSearch® analysis. Of eight CTC positive samples DLA product was analyzed directly after leukapheresis and after up to 18 months of cryo-conservation. CTC recovery was determined and morphology of detected CTCs was compared by evaluating DAPI and cytokeratin signals. Viable CTCs were enriched from fresh and thawed DLA products with the Parsortix™ system and cultured.

Results: Cryo-conservation does not impact CTC morphology and quality. A total CTC loss of 15.2% ± 9.7% was observed. However, the number of CTCs with intact nucleus and intact cytoplasm was reduced by only 6.0% ± 3.8%. CTC cultures could be grown from both fresh and frozen samples in two cases with high CTC numbers.

Conclusion: Cryo-conservation of DLA products enables storage of primary CTCs with low CTC loss while maintaining their quality and viability and will help to establish larger cohorts of cultivable primary CTCs for further functional studies.

For further information please contact: André Franken ([email protected])

Department of Obstetrics and Gynecology, Research Laboratory Hans Neubauer, University Hospital Düsseldorf

Seminar room 0.019 Key words: Diagnostic leukapheresis, CTC culture, cryo-conservation

Talk Nbr. T10



PRECLINICAL MODELS

HHIP-AS1 PROMOTES TUMOR SURVIVAL THROUGH STABILIZING DYNEIN COMPLEX 1 IN HEDGEHOG DRIVEN HUMAN BRAIN TUMORS

J.BARTL, A. Forget, D. Picard, N. Qin, S. Göbbels, M. Korsch, C. Mölders, A. Borkhardt, G. Reifenberger, O. Ayrault, M. Remke

Introduction:

Aberrant activation of the sonic hedgehog (SHH) pathway is one of the key drivers of tumorigenesis in aggressive pediatric brain tumors. However, SHH pathway inhibitors for the treatment of brain tumors demonstrated only limited responses in clinical trials indicating that a better understanding of the human SHH pathway is needed

Methods and Results:

Using an integrative transcriptomic analysis of several thousand normal and neoplastic tissues with and without SHH activation, we identified HHIP-AS1 as an important long non-coding RNA that is strongly associated with SHH signaling in pediatric brain tumors. HHIP-AS1 expression was significantly up- and downregulated upon SHH activation or inhibition, respectively. We also revealed that HHIP-AS1 shares a bidirectional promoter with HHIP and that the GLI2 transcription factor controls HHIP-AS1 expression. Transient and stable HHIP-AS1 knockdown (KD) led to a significant less aggressive phenotype in vitro and in vivo (in cell lines, patient-derived primary cultures and in orthotopic mouse models). We observed a significant reduction of proliferation, cell viability, clonogenicity, and an induction of cell cycle arrest with a higher mitotic index upon HHIP-AS1 KD. Additionally, RNA sequencing and proteomic analysis unraveled cytoplasmic dynein complex 1 intermediate chain 2 (DYNC1I2), which is a key mitosis regulator, as a target of HHIP-AS1. Further investigations revealed that HHIP-AS1 stabilizes DYNC1I2 via RNA–RNA interaction and that DYNC1I2 overexpression rescued the observed phenotypes.

Conclusion:

Taken together, our analyses reveal that HHIP-AS1 promotes tumorigenesis in SHH-driven brain tumors and identify a novel lncRNA as a component in the human SHH signaling pathway

For further information please contact: Jasmin Bartl ([email protected])

Pediatric Oncology, Hematology, and Clinical Immunology AG Remke, University Hospital Düsseldorf

Seminar room 0.019 Key words: Sonic Hedgehog Pathway, ATRT, Medulloblastoma, long non coding RNA

Talk Nbr. T11


CIT; EOM, MTT, MDEB CLINICAL STUDIES

Introduction of the DFG KFO 337 PhenoTImE

Alexander Roesch on behalf of the KFO 337 PIs

Despite the success of modern signaling targeted drugs and immune checkpoint blockers, the cure of patients with advanced cancers is still hampered by the resistance of tumor cells against drugs and immune mechanisms. Increasing evidence indicates that this is not solely driven by genetic evolution, but also by the epigenetic adaptive plasticity of tumor cell phenotypes. Current findings by us and others point to an understanding of cancer as a highly plastic system, in which tumor cell subpopulations dynamically switch between multiple identities depending on the current therapeutic and microenvironmental context. Interestingly, the underlying cell biologic principles seem to be similar across various cancer types. However, neither do we know the underlying molecular mechanisms, nor how we can influence them to overcome dynamic phenotype switching as a cause of therapy resistance.

The proposed clinical research unit PhenoTImE at the Essen University Hospital is based on a unique consortium of internationally renowned basic and clinician scientists with a shared research focus in innovative cancer therapies and tumor-immune cross-talk. Our overall hypothesis is that phenotypic tumor cell plasticity and immune escape are the major drivers for resistance against current anti-cancer therapies. Therefore, our overall goal is to comprehensively study the molecular mechanisms controlling phenotypic plasticity and immune escape in a distinct assembly of cancers (melanoma, pancreatic ductal adenocarcinoma, glioblastoma, and pilocytic astrocytoma) and to reciprocally test our findings across the different cancer entities. This complex task can only be achieved by a group effort bringing together expertise from different scientific fields.

Specifically, we focus on (i) epigenetic processes inside tumor cells (e.g. histone modifications via KDMs and HDACs or changes in lncRNA profiles, shifts in PI3K/AKT/PTEN signaling and metabolic programs), (ii) the reciprocal interaction with microenvironmental parameters, first of all the immune system (including T lymphocytes, neutrophils, and cytokines like TNFα or IFN), and (iii) the respective effects on tumor cell identities (e.g. cell differentiation state) and immune escape. The results will be integrated in comprehensive bioinformatic analyses of (epi-)genetically and transcriptionally profiled samples and of publicly available datasets, always in a clinicopathologic-prognostic context. Based on forward and reverse translational experiments incorporating human bio-samples, patient-derived tumor models, and different genetically engineered mouse models, we plan to open new treatment avenues and strategies that modulate the phenotypic shift of tumor cells to prevent drug resistance when combined with established therapies. Our long-term vision is to change and improve current treatment strategies and therapy monitoring in cancer also in the clinical setting beyond the requested funding period.

For further information please contact: Alexander Rösch ([email protected])

Department of Dermatology, AG Roesch University Hospital Essen

Seminar room 0.019 Key words: Talk Nbr.

T12


RADIATION ONCOLOGY AND IMAGING CLINICAL STUDIES

PSMA-PET DETECTS M1 DISEASE IN MORE THAN HALF OF A “NONMETASTATIC” CASTRATION-RESISTANT PROSTATE CANCER

SPARTAN-LIKE POPULATION

Wolfgang Fendler, Manuel Weber, Amir Iravani, Michael S. Hofman, Jérémie Calais, Johannes Czernin, Harun Ilhan, Eric J. Small, Matthew R. Smith, Tobias Maurer, Ken Herrmann, Thomas A. Hope, Isabel Rauscher, Anil Londhe, Matthias Eiber, Boris Hadaschik

Introduction:

We aim to characterize true disease extent in patients with non-metastatic castration-resistant prostate cancer (nmCRPC) using PSMA PET.


We retrospectively screened PSMA-PET databases (n = 8825 patients) from 6 high-volume PET centers, including Essen. Patients (n = 200) with nmCRPC were included in this study based on documented CRPC during continuous androgen-deprivation therapy (ADT), prostate-specific antigen (PSA) > 2 ng/mL and negative conventional imaging, similar to the SPARTAN trial. The primary end point was detection rate on PSMA-PET, including local/pelvic disease and distant metastatic (M1) disease. PSMA-PET was interpreted locally by one unblinded reader and centrally by two blinded readers.

Result: PSMA-PET was positive in 196 of 200 (98%) study patients overall, 111 of 115 (97%) with PSA doubling time ≤ 10 months, and 85 of 85 (100%) with Gleason Score ≥ 8. 55% of patients had local recurrence, 54% had pelvic nodal (N1), and 55% had any extra-pelvic distant metastatic disease despite negative conventional imaging (39% M1a, 24% M1b, 6% M1c). pN1 status (Odds ratio, OR 2.8, 95%CI 1.3-6.2, p=0.01*), primary radiation therapy of the prostate (OR 3.0, 95%CI 1.5 - 6.1, p<0.01*) and prior salvage therapy (OR 4.6, 95%CI 2.0 - 10.8, p<0.01*) were significantly associated with PSMA PET M1-disease. PSMA PET M1-disease was significantly associated with management change towards a lower rate of targeted salvage therapy (31 versus 66%, *p<0.01) and a higher rate of systemic treatment using novel androgen signaling inhibitors (39 versus 19%, *p=0.01).

Conclusions:

PSMA-PET detects M1 disease in more than half of “nm”CRPC patients. Thus, a high rate of M1 disease is expected in SPARTAN-like patients, meeting the apalutamide label.

For further information please contact: Wolfgang Fendler ([email protected])

Department of Nuclear Medicine, AG Herrmann/Fendler, University Hospital Essen

Seminar room 0.019 Key words: CRPC, PSMA, prostate, cancer, PET Talk Nbr.

T13


RADIATION ONCOLOGY AND IMAGING EX VIVO STUDIES / CORRELATIVE

SCIENCE

Motion effects in proton treatments of hepatocellular carcinoma- Interplay in 4D robustly optimized pencil beam scanning plans

T. Pfeiler, C. Bäumer, D. Geismar, S. Peters, J. Wulff, B. Timmermann

Introduction:

Regarding radiation therapy with protons, pencil beam scanning (PBS) enables better dose conformality for complex anatomical geometries than passive proton scattering, but is more susceptible to organ motion. Particularly, the interplay of organ motion and beam scanning might result in a displacement of the individual beamlets (‘spots’), which causes additional dose distortions (‘interplay effect’). Novel 4-dimensional treatment planning approaches have been developed to increase the robustness of PBS plans against motion.


The current in-silico study investigates the use of 4D robust optimization to maintain sufficient target coverage in the presence of organ motion, while sparing healthy tissue, for hepatocellular carcinoma. A facility-specific beam time model was used for the clinical evaluation.

Results: 4DDD analyses of 11 target volumes did not show an improvement of the target coverage using 4D robust optimization, but a reduction of the dose to close-by organs at risk. The average normal liver dose could be decreased by almost 6% compared to non-robustly optimized PBS plans and by 16% compared to double scattering plans when implementing 4D robust optimization.

Conclusion:

Except for some small tumors with large motion amplitudes, 4D robustly optimized PBS plans were found to be clinically acceptable even without supplementary motion mitigation techniques.

For further information please contact: Christian Bäumer ([email protected])

Medical Physics WPE, University Hospital Essen

Seminar room 0.019 Key words: proton therapy, pencil-beam scanning, HCC, robust optimization

Talk Nbr. T14


RADIATION ONCOLOGY AND IMAGING PRECLINICAL MODELS

Targeting antioxidant-associated mitochondrial carboxylate (mCB) transport systems to increase cancer cell radiosensitivity in the context

of acute and chronic hypoxia

Hlouschek Julian, Ritter Violetta, Hansel Christine, Wirsdörfer Florian, Klein Diana, Jendrossek Verena, Matschke Johann

Introduction:

Tumor hypoxia and heterogeneity acquired in a hypoxic tumor environment remain major obstacles to successful radiotherapy. We have shown that adaptation of cancer cell metabolism to cycling severe hypoxia and intermittent reoxygenation promotes resistance to chemotherapy and radiotherapy1,2. Here we aimed to gain insight into the role of mitochondrial carboxylate (mCB) transport systems for hypoxia-induced metabolic reprogramming and associated radiation resistance.


We validated expression of mCB transport proteins (mCB-TP) in anoxia/reoxygenation-tolerant (ART) and control cells of NSCLC, prostate, glioblastoma under normoxic (20% O2) and severely hypoxic conditions (0.2% O2). Consequences of genetic or pharmacologic inhibition of mCB-TP alone or in combination with ionizing radiation (IR) on cellular and mitochondrial redox homeostasis, cell metabolism and radiosensitivity were determined.

Results:

Exposure to acute, chronic-cycling hypoxia or IR enhanced the expression of mCB-TP. Genetic or pharmacologic inhibition of mCB-TP increased cytotoxic effects of IR and overcame acquired radioresistance of ART cells. Transporter-inhibition affected cellular and mitochondrial redox homeostasis, lowered mitochondrial metabolism, altered metabolic demand of cancer cells and this was associated with slowed DNA repair after IR3. SLC25A10 protein expression in mouse xenograft tumors was highly heterogeneous and mostly confined to hypoxic tumor regions4. Finally, overexpression of mCB-TP-mRNA in publically available lung and prostate patient data (Kaplan Meier plotter) went along with reduced survival of those patients.

Conclusion:

Our data highlight mCB-transport-systems as innovative therapeutic target to enhance cancer cell radiosensitivity and overcome chronic hypoxia-induced radioresistance in vitro and in vivo thereby tackling a clinically relevant problem.

For further information please contact: Johann Matschke ([email protected])

Institute of Cell Biology (Cancer Reasearch), AGI-Molecular Cell Biology, University Hospital Essen

Seminar room 0.019 Key words: Chronic cycling hypoxia, Radiation resistance, Metabolic reprogramming, Antioxidant capacity, DNA repair

Talk Nbr. T15


EXPLOITATION OF ONCOGENIC MECHANISMS EX VIVO STUDIES / CORRELATIVE

SCIENCE

The analysis of clonally related sibling cells to monitor transformation and developmental dynamics in CLL

Marc Seifert, Jan Dürig, Bettina Budeus

Introduction:

Transformation of the cellular origin and the gradual development CLL is poorly understood. The first genetic lesions occur already in hematopoietic stem cells and then accumulate over time. Intraclonal diversification of B cell receptors (BCR) is frequent in CLL. We showed previously that CD5+ B cells expanding in germinal center (GC) reactions represent the cellular origin of CLL. So far, CLL research focused on either early or final stages, as precursor cells or tumor cells were analyzed alone. Thus, the transformation of B cells into CLL is still unexplored. This is due to the often decade-long tumor growth and accumulation of transforming events until CLL manifestation. Our strategy to shed light on this important phase is to analyze long-lived memory B cells in CLL patients that were generated at the time of transformation.


BCR repertoire and single cell RNA-sequencing of CLL and corresponding sibling cells from small blood samples, primary or cryopreserved.

Results:

CLL sibling cells are phenotypically normal and clonally related to the tumor. These (often premalignant), long-lived memory B cells derive from the GC reactions giving rise to the tumor. We revealed that CLL development is not singular, but multi-centric and highly dynamical. Over time multiple tumor sub-clones are generated and compete for outgrowth.

Conclusion:

Our approach allows determining the dynamic evolution of CLL and the chronological course of transforming events.

For further information please contact: Marc Seifert ([email protected])

Institute of Cell Biology (Cancer Research), Immunology and Lymphomapathogenesis, Prof. Ralf Küppers, University Hospital Essen

Seminar room 0.019 Key words: CLL, clonal development, tumor monitoring Talk Nbr.

T16


EXPLOITATION OF ONCOGENIC MECHANISMS PRECLINICAL MODELS

Unravelling the molecular mechanisms of mutant RUNX1 in MDS stem cells

Samantha K Langer, Alyssa H Cull, Natalie Wossidlo, Peter A Horn, Stefan Heinrichs

Introduction:

The transcription factor RUNX1, a master regulator of normal hematopoiesis, is one of the most frequently mutated genes in Myelodysplastic Syndromes. However, the functional consequences, notably the downstream pathways and key target genes of mutant RUNX1 remain unclear. Here, we introduce a model to study the molecular functions of mutant RUNX1, by overexpressing the truncated dominant-negative isoform RUNX1a in hematopoietic stem and progenitor cells (HSPCs). We will use this model to discover novel druggable targets of mutant RUNX1.


Murine HSPCs were transduced with lentiviral vectors conferring the expression of RUNX1a. These cells were studied in vitro or analyzed in vivo after transplantation. Gene expression analysis was performed in sorted Lin- Kit+ cells (LK) and Lin- Kit+ Sca1+ cells (LSK) before and after RUNX1a-expression was turned off. Genomic DNA-binding sites were determined using chromatin immunoprecipitation followed by sequencing (ChIP-Seq).

Results:

Overexpression of RUNX1a immortalized mouse HSPCs in vitro. Reversal of RUNX1a expression induced differentiation and cell death. In vivo RUNX1a-expressing cells expanded competitively in the bone marrow and at lower frequencies in the peripheral blood. Both in vitro and in vivo we found an expansion of an immature subpopulation (LSK) with self-renewal activity. We performed gene set enrichment analysis on gene expression data from these cells and selected for genes highly regulated upon abrogation of RUNX1a-expression. To further narrow down the potential targets for mutant RUNX1 signaling, we identified direct targets using ChIP-Seq.

Conclusion:

Our model will allow identifying essential targets of mutant RUNX1 that would be of interest for specific drug development.

For further information please contact: Samantha Langer ([email protected])

Institute of Transfusion Medicine, Heinrichs Lab,, University Hospital Essen

Seminar room 0.019 Key words: MDS, RUNX1, mouse model, essential targets Talk Nbr.

T17



Mechanism of metastasis and vulnerabilities of BAP1-mutant tumors

L.M.O. Barbeau* 1,2 ; A. Bazarna* 1,2 ; K. Krengel 1,2 ; S. Mergener 1,2; J.T. Siveke 1,2; S. Peña-Llopis 1,2

Introduction:

Kidney tumors are mainly classified as clear-cell renal cell carcinomas (ccRCC) and 15% of the patients show inactivation of the tumor suppressor gene BAP1. Although BAP1 loss is associated with aggressive tumors, metastasis and poor patient survival, the molecular mechanisms subjacent are unknown.

Results:

We have found that mutated BAP1 is correlated with high expression of a small non-coding microRNA (miRNA) cluster involved in the development of metastasis. Patient levels of these miRNAs are positively correlated with higher incidence of metastases and poor overall survival.

Preliminary data suggest that BAP1 represses in vitro the expression of the miRNAs cluster at their promoter, which leads to less tumor metastasis in vivo. To understand the mechanism, systematic identification of the proteins in the BAP1 complex at the miRNAs promoter is determined by DNA pull-down assay followed by mass spectrometry, and will be further characterized in vitro. In addition, we are investigating the genetic vulnerabilities of mutated BAP1 tumors using a large-scale RNA interference screen to identify synthetic lethal interactions in ccRCC mutant BAP1 cell lines. The top hits from the screen will be validated in vitro in mutant BAP1 driven-cancer cell lines and further validated in vivo in metastatic mouse models.

Conclusion:

Based on these evidences, we aim to uncover the molecular mechanism of tumor metastasis caused by BAP1 loss and identify potential therapeutic targets.

For further information please contact: Barbeau, L. and Bazarna, A. ([email protected]; [email protected])

DKTK Division of Translational Oncology, West German Cancer Center (WTZ) Translational Genomics in Solid Tumors (AG Peña-Llopis), University Hospital Essen

Seminar room 0.019 Key words: ccRCC, BAP1, metastasis, microRNAs, synthetic lethality

Talk Nbr. T18



SCIENCE

Profiling immune cell types in glioblastoma using transcriptomes

I-Na Lu1, Celia Dobersalske1, Katja Farhat1, Mihaela Keller1, Martin Glas1,2, Björn Scheffler1 and Igor Cima1

Introduction:

Immunotherapy is a promising, yet challenging approach for treating glioblastoma. We hypothesize that the unbiased profiling of immune cell types in glioblastoma tissues may reveal unknown immunologic networks associated with disease outcomes.


Here, we report the creation of a transcriptome reference map composed of 84 different immune cell types and a novel algorithm that can be used to profile the immunologic landscape of human tissue samples.

Results:

By applying our method to RNA-Seq data derived from a collection of 166 glioblastoma tissues, we identify two subgroups of patients with distinct immune cellular landscapes. Surprisingly, these subgroups have different clinical outcomes. Moreover, by means of machine learning we unexpectedly find that hematopoietic progenitors of the myeloid and B cell lineages are important predictors of patient survival. Our findings are currently validated in patient-derived samples using multiparametric flow cytometry and in vitro functional studies.

Conclusion:

This unbiased “systems immunology” approach allows us to interrogate the cellular composition of any tissue sample. Applied to glioblastoma, we may uncover new candidate biomarkers and therapeutic targets in the field of immunotherapy that may be missed using more targeted approaches.

For further information please contact: I-Na Lu ([email protected])

Translational Neurooncology, Prof. Scheffler, University Hospital Essen

Seminar room 0.019 Key words: Glioblastoma, Systems Immunology, Machine Learning, Hematopoietic Progenitors, Immunotherapy

Talk Nbr. T19


Abstracts for POSTERS



Targeting cancer stem cells and immune escape mechanisms in Glioblastoma by inhibition of canonical Wnt/β-catenin-signaling

Philippe Aretz, Katharina Koch, Nerantzoula Tsiampali, Suad Yusuf, Constanze Uhlmann, Ann-Christin Nickel, Abigail K. Suwala, Rüdiger V. Sorg, Jaroslaw Maciaczyk and Ulf D. Kahlert

Introduction/Objective: Glioblastoma (GBM), the most common malignant primary brain tumor, is a lethal disease with currently only unsatisfying treatment options available. Recent therapeutic approaches evaluate targeting of GBM stem-like cells (GSC), which are suspected to be responsible for the initiation, therapy resistance and lethality of the tumor. One important driver of stemness is Wingless (Wnt)-signaling. By direct targeting of beta-catenin (CTNNB1) - the central signaling mediator of the canonical branch of Wnt with the small molecule inhibitor MSAB, we want to evaluate its therapeutic potential as a novel therapeutic option for GBM.

Recent studies further indicate the involvement of Wnt/beta-catenin signaling in regulating immunological processes during development and disease. We therefore also investigate if Wnt signaling is involved in the immunogenicity of GBM cells.

Methods: The therapeutic effect of MSAB on GSC enriched neurosphere cultures (n=4) was functionally assessed by monitoring any alterations in growth (MTT), apoptosis (Annexin-C) and proliferation (Ki67 incorporation). Stemness was determined on the molecular level by Luciferase-based Wnt reporter assay and expression of stem cell markers CD44 and Prominin1/CD133 on gene and protein level) as well as on functional level by assessing in vitro clonogenicity (Soft agar assay). Furthermore we examined a possible synergistic outcome of combining MSAB with the treatment with clinical standard of care drug Temozolomide (TMZ).

A genetic model of WNT blockade by RNA interference against CTNNB1 in the tumor cells was applied. Secretion of tumor and immune cells was measured by ELISA assay. Macrophages were isolated from human “buffy coats” using CD14+ MACS based separation and were cultured in tumor-conditioned medium. Differentiation markers were evaluated by FACS and migration ability by modified Boyden chamber assay.

Results: MSAB-treatment downregulates Wnt-signaling activity in all tested cell lines. Furthermore it decreases viability, proliferation, clonogenicity and increases apoptosis. Genetic blockade of canonical WNT caused a decrease of CCL2-expression and secretion. As CCL2 is an important chemotactic cytokine in tumor-immune-cell-interaction, further analysis will reveal the potential of anti-WNT therapy to impact the immunogenicity of the cancer cells.

For further information please contact: Philippe Aretz ([email protected])

Clinic for Neurosurgery, Division of Preclinical Research, University Hospital Düsseldorf

Ground Floor, Main Hall

Key words: WNT, CCL2, Glioblastoma, onco-immunology, targeted therapy

Poster Nbr. EOM P1



The regulatory effect of Type I IFNs on neutrophil angiogenic capability in tumor microenvironment

S. Bordbari , E. Pylaeva , I. Spyra, D.M. Hermann , I. Helfrich, S. Lang and J. Jablonska

Introduction:

The presence of type I IFNs is a potent driver of the tumor-associated neutrophil (TANs) transition from pro-tumor to anti-tumor state. Since neutrophils play a key role during tumor development, the aim of this study was to determine how TANs regulate tumor vascularization, and how IFNs impact this process.


We analyzed TAN infiltration and vasculature development in the tumors. We assessed hypoxic areas and the vessel leakiness. Pro-angiogenic gene expression was analyzed in TANs. Additionally, we assessed the capacity of TANs to stimulate proliferation, migration, tube formation and sprouting- of endothelial cells. To delineate the role IFNs in the

Results:

We could observe higher tumor growth and elevated TAN numbers in IFN-deficient mice. Such neutrophils show pro-angiogenic phenotype with significantly upregulated expression of pro-angiogenic factors. IFN-deficient mice demonstrate also more mature, functional phenotype of vasculature, which is untypical for tumors. . Co-culture of endothelial cells with pro-angiogenic TANs led to profound increase of their proliferation, migration, tube formation and sprouting capacity. In agreement, aortic ring assay showed more microvessel outgrowths after addition of IFN-deficient TANs.

Conclusion:

Taken together, our results suggest that IFN-deficient TANs exert their pro-angiogenic phenotype via stimulation of endothelial cell functionality and supporting pericyte maturation.

For further information please contact: Sharereh Bordbari ([email protected])

Department of Otorhinolaryngology, Translational Oncology, University Hospital Essen


Key words: IFNb, Tuomr-associated neutrophils, pro-tumor and anti-tumor neutrophils, tumor vascularization

Poster Nbr. EOM P2



Precise Modeling of Deletions in Myelodysplastic Syndromes and Acute Myeloid Leukemia

Alyssa Cull, Samantha Langer, Natalie Wossidlo, Peter Horn, Stefan Heinrichs

Introduction:

Myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are blood cancers characterized by abnormal expansion of hematopoietic stem and progenitor cells (HSPCs). Heterozygous deletions involving chromosome 5q are found in 10% of patients. Two distinct commonly deleted regions (CDRs) have been identified: the distal (5q32-5q33) and proximal (5q31) CDRs. While the distal CDR has been extensively studied, less is known about potential tumor suppressor genes within the proximal CDR. To address this, we created a preclinical model to study heterozygous deletions within 5q31.


Mouse HSPCs were derived from embryonic stem (ES) cells. The Cre/loxP system was used to excise genes/intergenic regions within mouse chromosome 18qB1, a region homologous to human 5q31. Ectopic expression of HOXB4 in ES cells and HSPCs supported both the differentiation and maintenance of ES-derived HSPCs.

Results:

On the ES cell level, loxP sites were introduced at defined locations within mouse chromosome 18qB1 using a CRISPR/Cas9 approach. ES cells were then differentiated into HSPCs. Cell surface immunophenotyping showed that 36±11% ES-derived HSPCs were CD45-positive. Additionally, 65±8% of these cells were lineage marker-negative, the majority of which were Kit-positive. Following expression of Cre recombinase in these HSPCs, a PCR assay confirmed the loss of the floxed region of chromosome 18qB1. Current work is focused on determining the phenotypic and functional consequences of this deletion.

Conclusion:

We have successfully created an in vitro tool to study tumor suppressor genes within the proximal CDR. In future, this system will also be used to model genetic aberrations found in other cancers.

For further information please contact: Alyssa Cull ([email protected])

Institute of Transfusion Medicine, Heinrichs Lab, Alyssa Cull, University Hospital Essen


Key words: MDS, AML, tumor suppressors, model system, stem cells

Poster Nbr. EOM P3



The role of the neurotrophin receptors, TrkA/NTRK1 and TrkB/NTRK2, in modulation of the radiation response of cancer cells

Christina Hassiepen, Ines Rudolf, Vivian Boron, Aashish Soni, George Iliakis, Alexander Schramm

Introduction: Neuroblastoma is the most common extracranial tumor of childhood and shows high diversity in disease outcome. While in some patients tumors differentiate spontaneously, in others the disease spreads aggressively and even after successful initial therapy tumor relapse might occur. High expression of TrkA/NTRK1 has been found to be associated with a good prognosis, while high TrkB/NTRK2 expression on the other hand is associated with an unfavorable outcome. Both, TrkA/NTRK1 and TrkB/NTRK2 are members of the neurotrophin receptor family, which is involved in multiple processes during neuronal development including differentiation and apoptosis. In vitro models of neuroblastoma with different TrkA/NTRK1 and TrkB/NTRK2 levels suggested a role for neurotrophin receptors in modulation of chemo- and radiation resistance.

Materials and Methods: We previously established inducible TrkA/NTRK1 or TrkB/NTRK2 overexpression in the human neuroblastoma cell line SH-SY5Y. To investigate the effects of TrkA/NTRK1 and TrkB/NTRK2 expression and activation in the context of response to irradiation (IR), we monitored changes in cell-cycle distribution by PI-staining and H3pS10-Assay. The effects of TrkA/NTRK1 and TrkB/NTRK2 overexpression and activation in combination with different irradiation intensities were analyzed by MTT and colony formation assay.

Results: Cell cycle analysis of TrkA/NTRK1 overexpressing cells revealed a dysfunctional G2/M checkpoint indicated by the presence of mitotic cells upon IR. Abrogation of IR-induced G2 block by TrkA/NTRK1 is epistatic to ATM or ATR inhibition, while small molecule-mediated inhibition of TrkA/NTRK1 by Loxo-101 rescued the IR-induced G2 checkpoint. By contrast, no changes in cell-cycle distribution were detected upon overexpression and activation of TrkB/NTRK2. However, cells with overexpression and activation of TrkB/NTRK2 showed increased long term survival upon irradiation.

Conclusion: Our experimental data indicate that both TrkA/NTRK1 and TrkB/NTRK2 are modulators of the radiation response. While increased activity in SH-SY5Y cells causes DNA-damage independent cell-cycle progression, increased signaling was characterized by an increased long-term survival upon irradiation. Both findings are in line with the clinical data showing a correlation of high expression with a favorable outcome of TrkA/NTRK1 and linking high expression of TrkB/NTRK2 with an unfavorable prognosis.

For further information please contact:

Christina Hassiepen ([email protected]) Molecular Oncology,AG Schramm, University Hospital Essen


Key words: TrkA/NTRK1, TrkB/NTRK2, Neuroblastoma, Radiation, Oncology

Poster Nbr. EOM P4



Impact of the gut microbiota on colorectal cancer and immunotherapy

Erik Lange, Alexandra Adamczyk, Jan Kehrmann, Astrid M. Westendorf

Introduction:

Colorectal cancer is a major cause of incidence and mortality worldwide. Thus, improved therapeutic approaches are required to reduce the global burden. Microbial dysbiosis in the gut has been strongly associated with the development of colorectal cancer. In this study, we explore the effect of antibiotic treatment and immunotherapy on the development of colon cancer in two different mouse models.


Colitis-associated colon cancer was induced in BALB/c mice using the AOM/DSS mouse model and in a second model, CT26 colon cancer cells were injected subcutaneously into the right flank of BALB/c mice. In both experimental setups mice were treated either with antibiotics in the drinking water, immune checkpoint inhibitor PD-L1 or a combination of both. Stool samples were collected and microbiome analyses were performed using IMNGS for the analysis of the 16S rRNA high-throughput sequencing datasets. In addition, tumor development was monitored and the immunoprofile was determined by flow cytometry and Luminex-technology.

Results:

As shown by 16S rRNA high-throughput sequencing, antibiotic therapy strongly modulates the bacterial composition. Interestingly, our results indicate that antibiotic therapy as well as PD-L1 antibody treatment reduces the tumor burden. However, when combining both treatments this protective effect is completely abolished. Immunological analyses of the tumors reveal only minor changes in the immune cell composition.

Conclusion:

Our results show that the gut microbiota affects the development of colon cancer but also the success of the immunotherapy. Therefore, further experiments are needed to clarify the underlying immunological mechanisms.

For further information please contact: Erik Lange ([email protected])

Institute of Medical Microbiology, Prof. Dr. Astrid Westendorf, Infection Immunology, University Hospital Essen


Key words: colorectal cancer, microbiome, immunotherapy, antibiotics

Poster Nbr. EOM P5



Molecular Mechanisms in the Pathogenesis of Composite Lymphomas

Anna Lollies1, Markus Schneider2, Sylvia Hartmann2, Marc Andree Weniger1, Patricia Johansson3, Jan Dürig3, Enrico Tiacci4, Stephan Mathas5, Ludger Klein-Hitpass1, Martin-Leo Hansmann2 and Ralf Küppers1

If two distinct lymphomas occur concurrently in a patient this is named composite lymphoma. Such lymphomas often involve a classical Hodgkin lymphoma (HL) and a B cell-Non-Hodgkin lymphoma (B-NHL). Recently, several studies analyzing selected candidate genes have identified shared as well as distinct transforming events in single genes of clonally related composite lymphomas, indicating that the malignant cells developed separately from a common precursor cell. In the transformation process, distinct genetic lesions happened in the daughter cells of the common malignant precursor and lead to the development of two distinct lymphomas from one cell of origin. Thus, composite lymphomas are very elegant and unique models to study the multi-step transformation process in lymphomagenesis. Here, we performed whole exome sequencing of isolated lymphoma cells from several composite lymphomas involving clonally related HL and B-NHL as well as B- and T-cell-NHL combinations with the aim to identify shared as well as distinct genetic lesions in composite lymphomas. Analysis of the immunoglobulin variable region genes of B cell composite lymphomas showed that most cases were clonally related. The exome sequencing analysis will allow us to further explore the oncogenic mechanisms in the pathogenesis of composite lymphomas. Our preliminary evaluation of the whole exome sequencing data indicates that in all cases analyzed by us, numerous shared as well as distinct non-synonymous mutations are found.

For further information please contact: Anna Lollies ([email protected])

Institute of Cell Biology (Cancer Research), AG Küppers, Prof. Ralf Küppers, University Hospital Essen


Key words: Composite Lymphomas, Pathogenesis, Whole exome sequencing

Poster Nbr. EOM P6



PGRMC1 Promotes Tumor Progression of Breast Cancer via Up-Regulation of ERα Expression

Marina Ludescher, Vanessa Stahlhut, Nina Kessler, Nadia Stamm, Berthold Gierke, Michael Pawlak, Annamaria Marton, Csaba Vizler, Zaklina Kovacevic, Des Richardson, Tanja Fehm, Hans Neubauer

Introduction:

The hormone receptor, progesterone receptor membrane component-1 (PGRMC1) is up-regulated in breast cancer and elevated expression of PGRMC1 is associated with increased tumor growth and poor outcome, suggesting a contribution of PGRMC1 in breast cancer carcinogenesis. However, the function of PGRMC1 in breast cancer, its activation mechanism and the signaling pathways involved are not fully understood. Therefore, the aim of the present study was to investigate the role of PGRMC1 in breast cancer progression and cancer-associated signaling pathways.


For this purpose, the effect of PGRMC1 over-expression and silencing on cellular proliferation was examined in vitro and in a xenograft model. Since the function of PGRMC1 was suggested to be regulated by differential phosphorylation, the PGRMC1 phosphorylation-status and the significance of PGRMC1 phosphorylation on cellular viability was investigated. Further studies also assessed key cancer-related signaling pathways, which could be regulated by PGRMC1.

Results:

Over-expression of PGRMC1 in the hormone-receptor positive cell-types, MCF7 and T47D, resulted in significantly enhanced proliferation and larger tumor volumes, while PGRMC1 silencing had the opposite effect. PGRMC1 phosphorylation at S56 and S181 was identified to be essential for enhanced proliferation. Analysis of PGRMC1-dependent expression and activation of proteins revealed up-regulation of estrogen receptor (ERα) and ERα-dependent genes, as well as facilitated epidermal growth factor receptor (EGFR) signaling.

Conclusion:

Our results emphasize the involvement of PGRMC1 in breast cancer progression and demonstrate the important role of PGRMC1 in key breast cancer signaling pathways. As such, PGRMC1 holds significant promise as a target for anti-cancer therapy.

For further information please contact: Marina Ludescher ([email protected])

Department of Obstetrics and Gynaecology, University Hospital and Medical Faculty of the Heinrich-Heine University Duesseldorf, University Hospital Düsseldorf


Key words: PGRMC1, breast cancer, estrogen receptor α, EGFR

Poster Nbr. EOM P7



Fibroblast activating protein expression is strongly associated with desmoplastic stromal reaction in different human cancers and may

serve as radio-therapeutical target

Mairinger, Elena; Buderath, Paul; Theurer, Sarah; Borchert, Sabrina; Mach, Pawel; Wessolly, Michael; Westerwick, Daniela; Walter, Robert Fred Henry; Schmeller, Jan; Kimmig, Rainer; Bankfalvi, Agnes; Schmid, Kurt Werner; Mairinger, Fabian Dominik

Introduction:

The appearance of tumor associated desmoplasia is a strong predictor of metastatic potential and tumor malignancy in different human cancers. Desmoplastic stromal reactions are rather a directed process than a coincidence. The underlaying biological process is not fully understood.


A retrospective study was conducted on a well characterized cohort of 149 patients suffering by different tumor entities (breast, ovary, thyroid) with varying amounts of desmoplastic stroma. FFPE samples were analyzed for their mRNA pattern using a custom-designed NanoString nCounter panels including a total of 209 target as well as 9 reference genes. Tumor associated immunohistochemical FAP protein expression was evaluated microscopically using semi-quantitative IHC scoring.

Results:

In our cohort we could show, that FAP is strongly associated with the appearance of desmoplastic stroma. Furthermore, FAP expression correlates with malignancy and metastatic potential in different tumor entities. Overall, 36% (54/149) of all analyzed cancers show strong FAP accumulation

Conclusion:

A recent study has shown FAP expression as a useful diagnostic tool in PET analyses. Furthermore, the authors suggest a potential role as a radiopharmaceutical target making FAP a promising marker for further research.

For further information please contact: Elena Mairinger ([email protected])

Institute of Pathology, Translational Cancer Research Group, University Hospital Essen


Key words: FAP, biomarkers, radiopharmaceutical target Poster Nbr.

EOM P8



The cellular cross-talk between emerging T cell acute lymphoblastic leukemia and thymic epithelial cells is mediated via the CXCL10/CXCR3

axis

Ashwini Patil, Stefanie Kesper, Marco Luciani, Ulrich Dührsen, Joachim R. Göthert

Introduction:

Thymic epithelial cells (TECs) are an essential component of the thymic microenvironment regulating T cell development. Cortical TECs (cTECs) express pivotal Notch-ligands such as Dll4 controlling T cell lineage commitment while medullary (mTECs) play a central role in negative T cell selection. Since acquired Notch1 mutations still require ligand-binding to exert augmented signaling we propose Dll4-expressing TECs playing a critical role in T cell acute lymphoblastic leukemia (T-ALL) development.


We used SCL/LMO1 double-transgenic mice to study the role of TECs in T-ALL leukemogenesis by flow cytometry, microscopy and gene expression analysis.

Results:

The SCL/LMO1 T-ALL preleukemic phase was characterized by the expansion of preleukemic CD8+CD4-TCRβintm thymocytes. Strikingly, thymocytes of 6-week-old SCL/LMO1 mice displayed a more than 100-fold upregulation of Notch1 compared to wild-type controls. Moreover, Fluorescence microscopy revealed a relative expansion of the BP1+ cTEC and reduction of the UEA+ mTEC areas in SCL/LMO1 thymi. Correspondingly, SCL/LMO1 absolute numbers of cTECs expanded while mTEC numbers declined. Gene expression profiling of sorted SCL/LMO1 TECs revealed marked upregulation of the chemokine CXCL10. Strikingly, CXCL10-upregulation by TECs could be induced in TEC cell lines in vitro by co-culture with preleukemic SCL/LMO1 thymocytes. Finally, we discovered in contrast to normal thymocytes a high proportion of preleukemic thymocytes expressing the receptor for CXCL10, CXCR3.

Conclusion:

Our data supports a model where emerging T-ALL lymphoblasts induce CXCL10 expression by expanding TECs which reciprocally feeds back to T-ALL via CXCR3.

For further information please contact: Ashwini Patil ([email protected])

Department of hematology, AG Göthert, University Hospital Essen


Key words: T cell acute lymphoblastic leukemia (T-ALL), thymic epithelial cells (TEC), CXCL10

Poster Nbr. EOM P9



SCIENCE

Proteomic landscape analysis in ICB-treated melanomas – preliminary results

Jan-Malte Placke, Jenny Bottek, Camille Soun, Felix Vogel, Markus Reinbold, Annett Urbanek, , Antje Sucker, Dirk Schadendorf, Ferdinand von Eggeling, Daniel Robert Engel, Alexander Roesch

Introduction:

Immune checkpoint blockade (ICB) is an effective therapy for patients with metastasized melanoma. Despite prolonged overall survival, many patients suffer from primary resistance. So far, there is no established predictive biomarker for ICB therapy. Previous data indicate that high tumor infiltration with CD8+ lymphocytes (TILs) is positively correlated with better patient outcome. However, the underlying tumor-intrinsic mechanisms that affect the mostly heterogeneous immune cell infiltration are still poorly defined.


FFPE tumor samples of 19 melanoma patients who received ICB were collected <6 months before therapy initiation. Radiological (RECIST) and clinical examination were used to classify patients into responders (n=5) or non-responders (n=14). Tumor sections were stained with antibodies against PD-L1 and CD8+ TILs to determine the distribution of TILs in the tumor samples. Furthermore, the spatial discriminating molecular patterns in the tumor were determined by MALDI imaging.

Results and Conclusion:

We observed intra- and intertumoral heterogeneity of the CD8+ TIL infiltrate and MALDI imaging spectra. Currently, MALDI imaging spectra are co-registered to the distribution of CD8+ TIL to identify characteristic mass spectra within the CD8+ TIL microenvironment. Next, LC-MS/MS analyses of tumor sections will be performed to further unravel the protein composition within the potentially predictive MALDI spectra. This analysis will identify tumor-intrinsic mechanisms that affect CD8+ TIL infiltration and tumor resistance.

For further information please contact: Jan-Malte Placke ([email protected])

Department of Dermatology, AG Prof. Roesch, University Hospital Essen


Key words: Melanoma, Immune checkpoint blockade, CD8 TIL, MALDI-Imaging

Poster Nbr. EOM P10



Antigen presenting properties of neutrophils during HNC tumor progression

Ekaterina Pylaeva, Elena Siakaeva, Sharareh Bordbari, Ilona Spyra, Anja Hasenberg, Stephan Lang, Jadwiga Jablonska

Introduction:

Neutrophils could have pro- or antitumoral properties depending on the activating stimulus. In head-and-neck cancer (HNC) development tumor-associated neutrophils (TANs) play a detrimental role as elevated numbers of these cells are associated with poor patient prognosis. However, the exact function of neutrophils during tumor progression remains unclear.


Migration, localization, antigen- presenting properties of neutrophils in lymph nodes (LNs) and their capacity to stimulate T cell activation during HNC tumor progression in TANs and LN-associated neutrophils were analyzed in both murine models and patient specimen.

Results:

Here we could show that during HNC progression neutrophils migrate to regional LNs and co-localize with T cells. Neutrophils migrate towards LN-derived factors, localize in subcapsular and trabecular sinuses or paracortical area of LNs, and establish functional synapses with T-cells. It could be observed both in mouse tumor model, but also in patient biopsies. We observe also that neutrophils in tumors and LNs have elevated APC markers expression. We could find that TANs and LN neutrophils are able to process antigens and present them to T cells. This in turn stimulate proliferation of T cells.

Conclusion:

Neutrophils in head-and-neck cancer play a role of antigen presenting cells. Since neutrophils are earlier infiltrating LNs than classical APC, it can have an important clinical implications for HNC therapy.

For further information please contact: Elena Siakaeva ([email protected])

Department of Otorhinolaryngology, Translational Oncology, University Hospital Essen


Key words: neutrophils, cancer, lymph nodes, antigen presentation

Poster Nbr. EOM P11



PGRMC1 Interacts with Enzymes of the Cholesterol Biosynthesis Pathway resulting in altered cholesterol metabolism and enhanced

proliferation of breast cancer cells

Nadia Stamm, Marina Ludescher, Hannah Asperger, Tanja Fehm, Hans Neubauer

Introduction:

Progesterone receptor membrane component 1 (PGRMC1) is a multifunctional protein which contributes to breast cancer progression. Previous studies revealed that PGRMC1 is involved in cholesterogenesis which is often deregulated during cancer progression, potentially through interaction with enzymes of the pathway.


Interaction of PGRMC1 with lanosterol demethylase (CYP51A1), squalene synthase (SQS) and stearoyl-CoA desaturase (SCD1), enzymes which are involved in cholesterogenesis and lipogenesis, was investigated by co-immunoprecipitation (Co-IP) and proximity ligation assay (PLA). Levels of cholesterol and estradiol were determined by mass spectrometry or ELISA in PGRMC1 overexpressing MCF-7 cells. ERα activity was measured at conditions of PGRMC1 overexpression and downregulation.

Results:

Co-IP and PLA revealed interaction of PGRMC1 with SQS, SCD1 and CYP51A1 in dependence of its phosphorylation status. Overexpression of PGRMC1 resulted in increased cholesterol- and estradiol levels, indicating a contribution of PGRMC1 to cholesterol homeostasis. A positive correlation between PGRMC1 and ERα expression level and -activation was identified, suggesting an activation of ERα signaling by cholesterol metabolites.

Conclusion:

The collected evidence points towards a functional connection between PGRMC1 expression and ERα activation. PGRMC1 is potentially involved in cholesterol homeostasis by modulation of enzymes of the cholesterol biosynthesis pathway, which results in elevated levels of cholesterol and its metabolites. Subsequent activation of ERα signaling could contribute to breast cancer progression and to development of resistance to estrogen deprivation therapy.

For further information please contact: Nadia Stamm ([email protected])

Department of Obstetrics and Gynaecology, AG Translationale Gynäkoonkologie, University Hospital and Medical Faculty of the Heinrich-Heine University Duesseldorf


Key words: PGRMC1, breast cancer, ERα, cholesterol biosynthesis

Poster Nbr. EOM P12



SCIENCE

The role of CD73 in glioblastoma growth

Nerantzoula Tsiampali, Katharina Koch, Beatriz Giesen, Ulf Kahlert and Jaroslaw Maciaczyk

Introduction:

Glioblastomas (GBM) are the most aggressive malignant brain tumours in adulthood. Despite strong research efforts effective treatment options are still limited. Glioma cell dissemination depends on molecular reprogramming of epithelial-to-mesenchymal transition-like (EMT-like) process with transcriptional activator ZEB1 as a pivotal regulator. In the current project we focused on the regulation of cell surface nucleotidase CD73 upon EMT modulation and investigated its potential as a novel therapeutic.


Genetic suppression models of glioma neurosphere cultures, in silico drug prediction and survival analyses were applied. Cells were subjected to a panel of functional cellular assays such as growth, anchor-independent sphere formation, proliferation and invasion. CD73 enzymatic activity was determined by high performance liquid chromatography (HPLC). Expression level was assessed by western blotting.

Results:

We found high expression of CD73 to be associated with significantly shortened overall survival of GBM patients. CD73 expression was suppressed in vitro upon blockade of ZEB1. Inhibition of CD73 resulted in significant suppression of GBM clonogenicity, cell invasion and proliferation, however, no significant effect could be observed upon selective inhibition of its enzymatic activity. Furthermore, application of phosphodiesterase inhibitor Pentoxifylline, inhibited CD73 expression and contributed to decreased viability of malignant gliomas.

Conclusion:

Our findings suggest that CD73 belongs to downstream mediators of ZEB1-driven EMT in GBMs. Interestingly the regulation of cell survival, proliferation and stemness was independent on enzymatic CD73 activity. These data indicate that CD73 may be promising novel therapeutic target in glioblastomas.

For further information please contact: Nerantzoula Tsiampali ([email protected])

Dept. of Neurosurgery, Experimental Neurooncology Lab, University Hospital Düsseldorf


Key words: GBM, ZEB1, CD73, Pentoxifylline Poster Nbr.

EOM P13



Prospective analysis of tumor subclones in recurrent glioblastoma

Vivien Ullrich, Sied Kebir, Emre Kocakavuk, Celia Dobersalske, Andreas Till, Daniel Trageser, Sven-Thorsten Liffers, Laurèl Rauschenbach, Madeleine Dorsch, Mathias Simon, Igor Cima, Pitt Niehusmann, Alexander Rösch, Ulrich Sure, Jens T. Siveke, Guido Reifenberger, Holger Fröhlich, Barbara M. Grüner, Martin Glas and Björn Scheffler

Introduction:

Fatal relapse occurs almost universally in glioblastoma (GBM), even in patients that initially benefit from the current gold standards involving postsurgical combinations of radio- and Temozolomide (TMZ)-based chemotherapy.


We investigated paired cell-/tissue samples assembling the pre- vs. post-status of TMZ-based chemotherapy. Transcriptional profiling, in vitro-, in vivo- and in situ studies were performed on the original patient material. Treatment approaches were evaluated in an orthotopic PDX model.

Results:

Investigations suggested ALDH1A1 as a marker for TMZ-resistant tumor subclones emerging in GBM recurrent disease. Analysis on paired samples from primary disease vs. GBM recurrence exposed that specifically these cells elevate levels of phosphorylated AKT. Consequently, combinations of TMZ and clinical grade AKT inhibitors suggested significant survival benefits over monotherapy attempts in the PDX model.

Conclusion and Outlook:

To investigate potentially underlying mechanisms of drug-resistance in these cells, we have established an innovative workflow using DEPArrayTM technology. Target subpopulations purified from FFPE patient samples will be molecularly profiled to determine genetic and epigenetic status changes. In parallel, DNA barcoding will be used to investigate clonal population dynamics of vitally targeted subclones on functional levels. Hereby we aim to discriminate whether the drug-resistant cells derive as a consequence of treatment-induced mutagenesis or whether they emerge by phenotypic plasticity that might facilitate the selection of “predisposed” subclones under the influence of first-line therapy.

For further information please contact: Vivien Ullrich ([email protected])

West German Cancer Center, DKFZ-Division of Translational Neurooncology, Prof. Scheffler, University Hospital Essen


Key words: Glioblastoma, Heterogeneity, Subclones, Drug resistance

Poster Nbr. EOM P14



Breast tumorigenesis regulation by autophagy and HER2

Vega‐Rubin‐de‐Celis, Silvia; Zou, Zhongju; Fernandez, Alvaro F.; Xiao, Guanghua; Kim, Min; Levine, Beth

Introduction:

HER2, an oncogenic receptor tyrosine kinase, is amplified in ~20% of breast cancer patients. Allelic loss of the autophagy gene beclin 1/BECN1 is associated with HER2 amplification in breast cancer; low beclin 1 mRNA expression is associated with increased risk of HER2+ breast cancer; and overexpressed HER2 and Beclin 1 interact in cultured cells. However, the functional significance of HER2/Beclin 1 interaction and of altered autophagy in HER2‐driven tumorigenesis is unknown.


We explored the regulation of autophagy by HER2 in breast cancer cells in vitro, and the effects of genetic and pharmacological approaches to increase autophagy on HER2‐driven breast cancer growth in vivo.

Results:

Endogenous HER2 interacts with Beclin 1 in multiple HER2+ breast cancer cells and inhibits autophagy. Mice with a knock‐in mutation in Becn1 (Becn1F121A) that leads to increased basal autophagy are protected from mammary tumorigenesis when crossed with mammary‐specific HER2 transgenic mice. Moreover, treatment of mice with HER2+ breast cancer xenografts with the Tat‐Beclin 1 autophagy‐inducing peptide inhibits tumor growth as effectively as a clinically used HER2 tyrosine kinase inhibitor (TKI). This inhibition of tumor growth is associated with a robust induction of autophagy, disruption of HER2/Beclin 1 binding, and a transcriptional signature that is distinct from that observed with HER2 TKI treatment.

Conclusion:

HER2‐mediated inhibition of autophagy likely contributes to HER2‐mediated tumorigenesis, and strategies to block HER2/Beclin 1 binding and/or increase autophagy may represent a new therapeutic approach for HER2+ breast cancers.

For further information please contact: Silvia Vega Rubin de Celis ([email protected])

Institute of Cell Biology (Cancer Research),Prof. Dr. Verena Jendrossek, University Hospital Essen


Key words: Autophagy, breast cancer, Beclin 1, HER2 Poster Nbr.

EOM P15



Functional analysis of CD30 in Hodgkin and anaplastic large cell lymphoma cell lines by CRISPR/Cas9-mediated gene knockout

Annika L. Weiß, Anna Lollies, Freya Kretzmer, Marc A. Weniger, Ralf Küppers

The tumor necrosis factor receptor family member CD30 is highly expressed on the malignant Hodgkin- and Reed-Sternberg (HRS) cells of classical Hodgkin lymphoma (cHL), but its role in the pathogenesis of this disease is controversially discussed. Based on the postulation of ligand-independent activity of CD30 signaling in HRS cells, high activity of the NF-κB and AP-1 signaling pathways has been linked to constitutive CD30 signaling. However, knockdown of CD30 in HRS cells lines led to contradicting results regarding its effect on cell viability, questioning the impact of CD30 signaling on this lymphoma entity. To resolve this issue, we established and optimized the CRISPR/Cas9 system in cHL, anaplastic large cell lymphoma (ALCL) and primary mediastinal B-cell lymphoma (PMBL) cell lines to achieve a complete knockout of CD30 and characterize the phenotype of CD30-depleted lymphoma cells. Flow cytometric analysis confirmed downregulation of CD30 surface expression. Genetic alterations were analyzed on single alleles by cloning and sequencing, confirming homozygous knockout of CD30. An increased fraction of apoptotic cells was found in cHL and ALCL cell cultures after knockout of CD30 compared to cultures treated with a non-targeting sgRNA. These results are evidence of the importance of CD30 for cHL and ALCL. Based on this we will examine the molecular and functional mechanisms of CD30 signaling and its interaction with the main pathways driving cHL lymphomagenesis.

For further information please contact: Annika Weiß ([email protected])

Institute of Cell Biology (Cancer Research), AG Küppers, University Hospital Essen


Key words: CRISPR/Cas9, lymphoma, CD30 Poster Nbr.

EOM P16



SCIENCE

Processing escapes: Induction of therapy resistance by altered proteasomal epitope processing

Michael Wessolly

Introduction:

Immune-checkpoint inhibitors using αPD1/αPDL1 antibodies have emerged as one of the most sophisticated cancer therapies. Although their successful application has been proven in many cancers, 60% of patients develop therapy resistance. We consider escape mutations in relation with deficient tumor antigen processing (processing escapes) as one possible explanation. We investigated their existence and impact in lung cancer patients.


Targeted panel sequencing was performed on 70 patients suffering from pulmonary neuroendocrine lung cancers (NELCs) and mutations influencing proteasomal processing were identified by in silico prediction. In addition, about 400 patient data from the TCGA data base were also taken for control purposes (lung adenocarcinoma and squamous-cell carcinoma).

Results:

Processing escapes were broadly identified in all tumor entities. According to correlation analysis, about 80% of all processing escapes were significantly associated with reduced expression of specific immune factors, referring to a reduced immune response against the tumor. The mutation load does also not differ between high-and low-grade tumors. Survival analysis revealed significantly impaired survival in correlation with high mutation load.

Conclusion:

Processing escapes may become a helpful tool to predict outcome of -therapy treated patients treated with immune-checkpoint inhibitors. Thereby, it hopefully helps to identify patients with bad prognosis.

For further information please contact: Michael Wessolly ([email protected])



Key words: Proteasomal processing, epitopes, immune-checkpoint inhibition, machine learning, explorative data analysis

Poster Nbr. EOM P17



Modeling MDS- associated Mybl2 haploinsufficiency in mouse HSPCs in vitro

Natalie Wossidlo, Samantha Langer, Alyssa Cull, Peter A. Horn, Stefan Heinrichs

Introduction:

Myelodysplastic Syndromes (MDS) are a group of diseases with diverse clinical phenotypes caused by somatic mutations in the hematopoietic stem and progenitor cells (HSPCs). The transcription factor MYBL2 is encoded by a gene located within a region of chromosome 20 that is commonly deleted in patients and is considered to act as a haploinsufficient tumor suppressor in MDS. Yet, the mechanism underlying the tumor suppressor function of MYBL2 remains unclear. To elucidate pathways associated with Mybl2, we aim to develop suitable cell culture model systems.


An RNAi-approach was used to knock down Mybl2 in mouse HSPCs. A Tamoxifen-inducible Cre/loxP system was used to excise the shRNA-encoding sequence, allowing to reverse the effects of the knockdown. Mybl2 re-expression vectors were developed to verify that the Mybl2 knockdown was required for the shRNA-associated phenotype.

Results:

We identified a single Mybl2-targeting shRNA that immortalizes mouse HSPCs in vitro. Cre-mediated excision of the shRNA resulted in growth arrest of the cells. First results from re-expression experiments, however, indicated that the maintenance of the cells’ phenotype was independent of wildtype Mybl2 expression suggesting potential off-target effects of the respective shRNA or lack of a spliced Mybl2 variant. Current work focuses on possible isoforms of Mybl2 and the modeling of point mutations in key MDS genes using CRISPR/Cas9.

Conclusion:

Knockdown of Mybl2 was not sufficient to immortalize HSPCs under the given culture conditions. We expect to be able to find genes that contribute to the transformation of Mybl2-haploinsufficient cells by modeling genetic lesions in addition to the established knockdown of Mybl2.

For further information please contact: Natalie Wossidlo ([email protected])

Institute of Transfusion Medicine, Heinrichs Lab, University Hospital Essen


Key words: MDS, Mybl2, haploinsufficient tumor suppressor, in vitro model

Poster Nbr. EOM P18



Investigating reciprocal regulations of nutrient starvation of glioblastoma stem-like cells

Suad Yusuf, Katharina Koch, …G Leprivier, J Maciaczyk,and UD Kahlert

Introduction:

Investigating reciprocal regulations of glucose starvation and WNT signaling in glioblastoma stem-like cells Glioblastoma (GBM) is a highly malignant primary brain tumor which is characterized by its poor prognosis for the patient due to a significant degree of therapy resistance and high recurrence rates. It is thought that a cell subpopulation called glioblastoma stem-like cells (GSCs), which are able to self-renew and survive extreme environmental conditions such as hypoxic or hypoglycemic environments, significantly contribute to the malignancy of GBM. Therefore, we want to unravel possible coherences between the canonical branch of Wingless (WNT) pathway, a highly phylogenetically conserved stemness-pathway, and the metabolic flexibility of GBM cells in nutrientdeprived microenvironments.

Methods:

In order to assess the effect of glucose deprivation on GSC-enriched cultures, we determined the cellular viability and quantified the WNT-activity both under glucose-depletion and physiological glucose conditions. Furthermore, we assessed the mRNA expression of several glucose-responsive-genes including c-MYC and ASNS after glucose starvation. Finally, through analysis of the cellular metabolome, we aim to elucidate metabolic adaptations induced by glucose-starvation in GSC cultures.

Results:

Our GSC cell lines (GBM1, JHH520, RAV19) show different levels of glucose-dependency, however glucose starvation reduces WNT activity (as assessed with luciferase-based reporter) and mRNA expression of the canonical WNT signaling mediator beta-Catenin in all our in vitro GSC cultures. Furthermore, we detect regulation of glucose-responsive genes in the GSC models which might be associated with the metabolic adaptations we observed under glucose depletion.

For further information please contact: Suad Yusuf ([email protected])

Clinic for Neurosurgery, Division of Preclinical Research, University Hospital Düsseldorf


Key words: Glioblastoma, t, WNT, starvation, metabolism Poster Nbr.

EOM P19



Syntaxin 18 (STX18) is a novel modulator of the radiation response in non-small cell lung cancer (NSCLC)

Thumser-Henner C, Kalmbach S, Sak A, Schramm A, Schuler M.

Introduction:

Lung cancer is the leading cause of cancer-related death in the world, and NSCLC accounts for 85% of lung cancers. Despite advances in diagnosis and treatment, the overall survival of lung cancer is poor. While newly developed therapies target specific tumor molecular aberrations, radiotherapy does not take into account tumor heterogeneity. We hypothesize that aberrant signal transduction pathways modulate the outcome of radiotherapy for NSCLC. Our team identified STX18, a t-SNARE protein involved in the transport between Golgi and endoplasmic reticulum, as a modulator of the radiation response in A549 cells and we aim to understand the underlying mechanisms of the radiosensitizing effect of STX18 knockdown.


A549 and H460 cell lines were transduced with a shRNA targeting STX18. Single clones were generated and in vitro assays, such as colony formation and cell cycle analysis by flow cytometry were performed.

Results:

STX18 knockdown resulted in an increased subG1 fraction after irradiation, and a decrease in colony formation. A549 showed a significantly decreased sensitivity after treatment with etoposide and staurosporine when STX18 was downregulated. In H460-shSTX18 cells a significant decrease of MMP-2 expression and activity was observed. Furthermore, downregulation of STX18 concomitantly decreased expression of the ER-stress protein CHOP in both cell lines.

Conclusion:

Our study identified STX18 as a radiosensitizer in two lung cancer cell lines. shRNA-mediated depletion of STX18 reduced MMP-2 expression and activity, suggesting that STX18 knockdown might also interfere with metastatic capacity. Furthermore, deregulation of ER proteins including CHOP is observed upon STX18 knock-down. We hypothesize that prolonged ER stress and subsequent apoptosis contributes to the radiosensitizing effect of STX18 knockdown.

For further information please contact: Clothilde Thumser-Henner ([email protected])

AG Molekulare Onkologie, Innere Klinik (Tumorforschung), University Hospital Essen


Key words: Non-small cell lung cancer, syntaxin 18, radiotherapy, targeted therapy

Poster Nbr. ROI P1



Proton therapy for base of skull tumors at West German Proton Therapy Center Essen (WPE)

Sindhu Nagaraja, Theresa Steinmeier, Ulrich Sure, Martin Glas, Stephan Lang, Stefan Mattheis, Stephan Tippelt, Sebastian Bauer, Jörg Wulff, Beate Timmermann

Introduction:

The base of skull (BoS) is a challenging site for local therapy due to its proximity to critical structures. At the WPE, proton therapy (PT) is applied for BoS tumors since 2013, forming a unique cohort for clinical research. Multidisciplinary expertise at the university hospital Essen ensures optimal patient (pat.) triage and appropriate medical care.


All pat. with BoS tumors treated at WPE were included in this analysis. Standardized data regarding patient characteristics, treatment and follow-up (FU) was collected in the prospective registry studies “KiProReg” and “ProReg”. Adverse events were documented before, during and after PT, and scored according to CTCAE v4.0.

Results:

448 pat. with BoS tumors (median age 22.8 y, range 0.9-84.6 y) were evaluable. 200 sarcomas (44.6%), 133 tumors of the central nervous system (29.7%) and 108 head and neck tumors (24.1%) were included. Regarding histopathology in each group, rhabdomyosarcoma, meningioma and squamous cell carcinoma were the most common entities. 366 pat. underwent subtotal resection (n=167) or biopsy only (n=199) before PT. 35.7% of pat. received concomitant chemotherapy. Median total dose was 55.8 Gy, median fraction dose was 1.8 Gy. Median FU after first diagnosis was 2.2 y (range, 0.2-26.1 y). At last FU, tumor control was achieved in 81.5%, 11.8% were deceased. Higher grade toxicities (CTCAE grade >2) during PT occurred in 171 pat. (38.1%), predominantly with leukopenia, mucositis, dysphagia or optic nerve disorder (no deterioration of vision observed). One year after PT, only 5 pat. (2.5%) had developed deterioration of preexisting or onset of CTCAE grade >2 toxicities.

Conclusion:

Results support good feasibility of PT for treatment of BoS tumors. However, a multidisciplinary management is essential. Further translational research is needed to improve outcomes and optimize balancing of efficacy and toxicity.

For further information please contact: Sindhu Nagaraja ([email protected])

Department of Particle Therapy, West German Proton Therapy Centre Essen (WPE) Prof. Dr. Beate Timmermann, University Hospital Essen


Key words: Proton Therapy, Base of skull tumors, sarcomas, central nervous system, head and neck

Poster Nbr. ROI P2



Proton Beam Therapy (PT) for brain tumors in childhood at WPE

S. Peters, S. Frisch, M. Stickan-Verfuerth , S. Plaude, C. Blase, U. Sure, M. Glass, S. Tippelt, G. Fleischhack, B. Timmermann

Introduction:

The aim of this study is to examine feasibility and early outcome after PT for brain tumors in childhood.


Between September 2013 and November 2017, 298 children (173 male, 125 female) with a median age of 5.9 years (range, 0.9-18.0 yrs.) with primary brain tumors were treated with protons and prospectively enrolled in the study “KiProReg registry”. Most common diagnosis were ependymomas and medulloblastomas. In 60.9% of the patients, gross total resection was achieved. 86.2% had no metastasis. Patients were treated according to national and international protocols.

Results:

Patients were treated either at initial diagnosis (19.1%) or at time of progression (80.9%). 49% had received Chemotherapy (CTX) before PT. Seventeen patients had irradiation before PT within the current PT field. Concomitant CTX was applied in 27.5 % of the cases. 60.1% were treated under daily sedation due to the young age. The median PT dose was 54.0 Gy (range, 24.0-72.0 Gy). The median follow-up time after last fraction was 11.4 months (0.0-51.8 m.). PT was well-tolerated. New CTCAE °4 acute toxicities occurred only regarding bone marrow (n=7). In 189 (63.6%) patients disease control was achieved at time of last follow-up(FU).

Conclusion:

Current data support good feasibility of PT in childhood primary brain tumors and early experiences for tumor control are promising. Data have to be confirmed after longer FU. For the same cohort, an analysis of imaging studies is in preparation, in order to evaluate imaging changes in cooperation with the reference neuroradiology center of the German pediatric brain tumor network.

For further information please contact: Sarah Peters ([email protected])

Department of Particle Therapy, Prof. Dr. B. Timmermann, University Hospital Essen

Ground Floor, small hallway

Key words: brain tumor , childhood cancer, proton therapy Poster Nbr.

ROI P3



Anti-malaria Drug Dihydroartemisinine Improves Radiotherapy

Sina Bader, Julia Wilmers, Verena Jendrossek, Justine Rudner

Introduction:

Dihydroartemisinine (DHA) is an anti-malaria drug that also show anti-neoplastic effects on tumors. DHA is activated in presence of Fe2+, thereby forming a reactive radical that, in turn, react with and damage other cellular components and ultimately result in cell death. Similarly, radiotherapy exerts its cytotoxic effects through generation of reactive oxygen species (ROS). Both reactive species can be antagonized by cellular antioxidants like glutathione. Here, we explore the mechanisms by which DHA induces cell death and address the question whether DHA combined with radiotherapy can improve the therapeutic outcome.


Short-term survival, lipid peroxidation, and mitochondrial ROS production was analyzed by flow cytometry and fluorescence microscopy, clonogenic potential was examined using colony formation assay. Changes in mRNA expression and protein levels were detected by qRT-PCR and Western blot.

Results:

DHA induces lipid peroxidation, a hallmark of ferroptosis, and facilitates ROS production at mitochondria. Moreover, DHA inhibits mitochondrial function at very low levels. At the same time, an anti-oxidative stress response is activated upon treatment with DHA, leading to upregulation of Xc transporter system (import of cysteine) and the transsulfuration pathway, both needed for glutathione synthesis. Despite the increased glutathione levels, co-treatment with DHA sensitizes cell to radiotherapy. In addition, inhibition of the Xc transporter by erastin improves cytotoxicity induced by DHA or radiotherapy.

Conclusion:

DHA is a promising drug improving radiotherapy.

For further information please contact: Justine Rudner ([email protected])

Institute of Cell Biology (Tumor Research), AG1 (Prof. Verena Jendrossek), University Hospital Essen


Key words: Dihydroartemisinine, radiotherapy, glutathione, reactive oxygen species

Poster Nbr. ROI P4



Combined Androgen Receptor and DNA damage response inhibition to enhance prostate-specific membrane antigen-directed radioligand

therapy of prostate cancer

Magdalena Staniszewska, Katharina Lückerath, Liu Wei, Caius G. Radu, Matthias Eiber, Johannes Czernin, Jasmin Klose, Ken Herrmann, Wolfgang P. Fendler

Introduction:

Metastastic castration-resistant prostate cancer (mCRPC) is a highly lethal disease. 177Lu-PSMA617, a novel radio-labeled peptidomimetic acts as a therapeutic alternative for patients with mCRPC. 177Lu-PSMA617 is labeled with the β-emitter Lutetium-177 and binds with high affinity to the extracellular domain of PSMA. PSMA is a plasma membrane glycoprotein highly overexpressed in mCRPC. 177Lu-PSMA617 radioligand therapy (RLT) reduces serum prostate specific antigen (PSA) levels in >50% of patients, along with significant improvements in quality of life. However, more than one third of patients will not respond to 177Lu-PSMA617 RLT. Therefore, more effective therapies of mCRPC are urgently needed. To improve the efficacy of RLT for mCRPC patients we therefore propose to combine Androgen receptor blockade (ARB), inhibition of Ataxia Telangiectasia and Rad3-related protein (ATRi), and inhibition of poly ADP ribose polymerase (PARPi) plus RLT in two xenograft models of prostate cancer in vivo.

Methods and Concepts:

Xenograft-bearing mice will be treated once daily with Enzalutamide (ARB), beginning 21 days before start of the combination therapy. ATRi or PARPi will commence one day before RLT by application of VE-822 or Olaparib. 15 MBq 177Lu-PSMA617 will be given once via the tail vein. Efficacy will be assessed by serial measurements of tumor volume and repeated 68Ga-PSMA11 small-animal PET/CT. Upon sacrifice, toxicity analysis will include complete blood count, complete metabolic profile and histopathologic analysis for organ damage.

Hypothesis and expected outcome:

The aim of this project is to demonstrate synergistic tumor growth inhibition and safety of combined ARB, ATRi/PARPi and RLT in models of mCRPC xenografts in vivo. We anticipate enhanced PSMA expression under ARB. We further anticipate acceptable safety and synergistic induction of replication stress and inhibition of tumor growth by ATRi or PARPi and 177Lu-PSMA617 RLT in vivo.

For further information please contact: Magdalena Staniszewska ([email protected]) Nuclear Medicine, AG Herrmann/Fendler, University Hospital Essen


Key words: mCRPC, PSMA, prostate, cancer, PET Poster Nbr.

ROI P5



comparison of the cellular response of DNA repair-deficient cells to photon and proton irradiation in vitro

Szymonowicz K, 1,3 Krysztofiak A, 1,3 van der Linden J, 1 Koska B, 2 Kern A, 2 Vüllings M, 2 Hlouschek J, 1 Timmermann B, 2 Jendrossek V, 1

Introduction:

With the increasing number of proton radiotherapy centers worldwide radiotherapy with protons is increasingly used in cancer therapy. However, potential differences in the biology of the DNA-damage induced and the resulting DNA damage response between irradiation with photons or protons are net yet well understood.


Here, we addressed potential differences in the necessity of non-homologous end joining (NHEJ) and/or homologous recombination repair (HRR) proteins for processing of DNA double strand breaks and cell survival upon photon and proton irradiation by using a panel of cell lines with genetic defects in either NHEJ or HRR, respectively. Therefore, we irradiated the cells with a similar dose of 3 Gy with X-ray photons, spread out Bragg peak (SOBP) protons or protons of the entrance plateau and compared the amount of the initial DNA damage and the kinetics of DNA repair by using γH2A.X between 30 min and 24h after irradiation. Moreover, we compared the effects of irradiation on long-term survival using standard colony survival assays.

Results:

The results gained from γH2A.X assay as well as from the clonogenic survival assays revealed differences in importance of a functional NHEJ or HRR for the repair of DSB induced by photons versus SOBP protons.

Conclusion:

Thereby our data point to potential differences in the biology of the DNA damage induced by proton versus photon irradiation and suggest that the genetic background regarding proteins involved in DNA repair might be important for the proper selection of combined treatment strategies with inhibitors of DNA repair proteins, proteins of the DNA damage response, or both.

For further information please contact: Klaudia Szymonowicz ([email protected])

Institute of Cell Biology (Cancer Research), University Hospital Essen


Key words: Proton irradiation, SOBP, Photon irradiation, DNA repair deficiency, clonogenic survival

Poster Nbr. ROI P6



The impact of radiotherapy for metastatic bone lesions in neuroblastoma.

Danny Jazmati, Jerome Doyene, Dirk Geismar, Julien Mertha, Nico Verbeek, Jörg Wulff, Christian Bäumer, Lorenzo Brualla, Thorsten Simon, Barbara Hero, Beate Timmermann

Introduction:

Neuroblastoma (NB) is the most common extracranial solid tumor in children. More than 50% present with metastatic lesions at diagnosis. Although in Germany radiotherapy was not proposed routinely so far, individual decision was taken to irradiate residual bony metastases with up to 36 Gy.


Data from the prospective, multicentre neuroblastoma trials NB97 and NB2004 were evaluated to identify the cohort of high risk neuroblastoma patients having been irradiated for bony metastases irradiated during front-line treatment approach.

Results:

18 patients were eligible for this analysis. The 2 - and 5-year LC rate was 83,3% and 51,4%, respectively. After a medium follow up time of 29 months (15 - 63) local recurrence/progression occurred in 9 patients developing predominantly within the previous RT-field (77,78%). The 2- and 5- year metastatic free survival rate was 77,8% and 39,9%, respectively. At the time of analysis 9 patients had deceased. In the majority of patients, RT was given to one metastatic site only (1 - 3). No correlation between the applied dose (20 - 45Gy) and LC rate could be demonstrated.

Conclusion:

As this is a small retrospective study, our data cannot prove the role of RT in residual metastatis sites. In order to provide evidence regarding the impact of radiotherapy for residual bony metastases, a larger cohort and a matched pair analysis would be desirable.

For further information please contact: Danny Jazmati ([email protected])

West German Proton Therapy Center (WPE), Beate Timmermann, University Hospital Essen


Key words: neuroblastoma, metastases, irradiation Poster Nbr.

ROI P7



Towards high-precision dose calculations for proton therapy

Nico Verbeek, Sabrina Smyczek, Jörg Wulff, Christian Bäumer, Danny Jazmati, Beate Timmermann, Lorenzo Brualla

Introduction:

PENH is a recently coded module for simulation of proton transport in conjunction with the general-purpose Monte Carlo (MC) code PENELOPE. The few existing general-purpose MC radiation transport codes are considered the golden standard in dosimetry. PENELOPE arguably has the most accurate radiation transport algorithm for the simulation of charged particle transport, however, it lacked up until the appearance of PENH of the possibility of simulating proton transport. Simulation of proton transport with PENELOPE will result in higher-precision proton therapy calculations and the possibility of accurately evaluating challenging dosimetric problems such as microbeams or small fields.


Results from simulations with PENH are compared with simulation data obtained from TOPAS MC and RayStation 6 MC. Simulated results were compared to experimental data obtained with the MatriXX PT 2D detector (IBA Dosimetry).

Results:

Depth dose profiles taken at varying radius from the central axis were tallied. The radius varied from the central axis up to 10 cm away from it. Excellent quantitative agreement is observed among the evaluated codes with the experimental data in the clinically relevant region.

Conclusion:

We conclude that the elaborate physics modeling of the PENELOPE/PENH code yields results consistent with measurements, enabling detailed MC studies on dosimetry in proton therapy.

For further information please contact: Nico Verbeek ([email protected]; [email protected])

Westdeutsches Protonentherapiezentrum Essen, Priv.-Doz. Dr. Lorenzo Brualla, University Hospital Essen


Key words: PENELOPE, PENH, Monte Carlo, proton Poster Nbr.

ROI P8


CLINICAL COMMUNICATION PLATFORM EX VIVO STUDIES / CORRELATIVE

SCIENCE

Development of a browser-based sample bank for multicenter liquid biopsy trials

Asperger H.1*, Cieslik J.1*, Naskou J.1, Meier-Stiegen F.1, Niederacher D.1, Neubauer H.1, Janni W.2, Fehm T.1 and the DETECT study group, * equal contribution, alphabetical order

Introduction:

In clinical multicentre liquid biopsy trials many blood samples from carcinoma patients, isolated tumour cells, and nucleic acids are processed and stored at different laboratories. In order to enable translational research projects to investigate their clinical value an important requirement is to assemble sufficiently dimensioned patient cohorts. The sample bank was designed to remedy this bottleneck and to create an option for cross-laboratory collaboration.

Materials and Results:

We collected the necessary information that the sample bank should contain such as sample-logistic, sample-processing, quality control and already compiled data. Afterwards, we created a web-application, which grants all the contributing centres access to our data. For the server-backend we used PHP (Hypertext Preprocessor) in combination with the relational database management system MySQL. Every laboratory can enter their data for a certain sample resulting in multiple entries per sample in the database. To summarise the available data, we programmed a caching script that merges the individual entries to one entry per sample. Each user can only edit the entry of his own laboratory. Every contributing centre can grant different access rights to their users. A core feature of the sample bank is the ability to select certain probes and to request them from a sample manager, who can then coordinate the exchange of the samples. Besides the direct sample management, we plan to establish a communication channel for our trial group.

Conclusion:

Within the DETECT-CTC trial program we established a virtual sample bank which will simplify sample exchange within the consortium and will improve the basis for translational liquid biopsy studies.

For further information please contact: Asperger, H. and Cieslik ([email protected])

Department of Obstetrics and Gynecology, Research Laboratory Hans Neubauer, University Hospital Düsseldorf

Ground Floor, long hallway

Key words: Liquid Biopsy, virtual sample bank, translational research

Poster Nbr. CCP P1



PRECLINICAL MODELS

The long non-coding RNA HOTAIRM1 mediates radioresistance in glioblastoma

Ulvi Ahmadov, Daniel Picard, Manuela Silginer, Marlen Melcher, Alina Winkelkotte, Marija Trajkovic-Arsic, Nan Qin, Maike Langini, Jasmin Bartl, Felix Distelmaier, Jens Siveke, Kai Stühler, Arndt Borkhardt, Michael Weller, Patrick Roth, Guido Reifenberger, Marc Remke

Introduction:

Glioblastoma (GBM) is the most common malignant brain tumor in adults and the prognosis for GBM patients remains poor despite aggressive multimodal therapies. The vast majority of GBM are resistant to radiation and chemotherapeutic agents either upfront or during the course of treatment. The role of long non-coding RNAs (lncRNA) as novel epigenetic regulators of gliomagenesis and therapy resistance remains unclear.

Materials, Methods and Results:

Using our bioinformatics approach, HOTAIRM1 was detected one of the most significantly overexpressed lncRNAs in short-term GBM survivors. We next demonstrated that high HOTAIRM1 expression constitutes a biomarker of poor prognosis independent of IDH1 mutational status in two independent, non-overlapping gene expression datasets. Upon HOTAIRM1 knockdown in both transient and stable models, we observed a decrease in cell viability, migration and colony formation. We performed RNA sequencing and mass spectrometry analyses revealing that mitochondrial function genesets were significantly overrepresented upon HOTAIRM1 knockdown. Furthermore, Seahorse Mitostress assay as well as mitochondrial and cytoplasmic ROS staining supported impaired mitochondrial function upon HOTAIRM1 knockdown. Moreover, we performed in vitro irradiation analyses and observed increased radiosensitivity upon HOTAIRM1 knockdown. Finally, we revealed extended survival in orthotopic GBM xenografts upon HOTAIRM1 knockdown in irradiated tumor-bearing mice.

Conclusion:

Our data reveals that HOTAIRM1 mediates radioresistance in GBM through ROS regulation. Thus, HOTAIRM1 may constitute a predictive biomarker for radiosensitivity and a promising therapeutic target for this fatal disease.

For further information please contact: Ulvi Ahmadov ([email protected])

AG Remke, University Hospital Düsseldorf


Key words: Glioblastoma, long non-coding RNAs, HOTAIRM1, radiation

Poster Nbr. MDEB P1



CLINICAL STUDIES

Genetic testing exonerates the majority from the risk present in only a few: Differential diagnosis of BAP1 Cancer Syndrome in patients with

uveal melanoma

Arjmand Abbassi, Y.; Le Guin, C.; Lohmann, D.; Zeschnigk, M.

Introduction:

Uveal melanoma (UM) is a cancer of the eye. Loss of one chromosome 3 (M3) in UM is a reliable prognostic marker of metastatic progression. Most UM with M3 show somatic mutations of BAP1. Some rare patients are constitutional heterozygous for mutant BAP1 thus having a heritable predisposition to UM and diverse other neoplasms (BAP1 Cancer Syndrome, BAPCaS). In some tumor predisposition syndromes genetic testing has been established to exclude tumor predisposition in sporadic cases. Therefore, this study sought to find out if such a strategy is also feasible for patients with UM.


Analysis of chromosome 3 loss was done in 72 consecutive UMs with M3. Variant analysis of BAP1 was performed on tumor and blood DNA to determine or exclude heterozygosity for the tumorigenic variants.

Results:

Sequencing results were obtained from 64 tumors. Hemizygous pathogenic variant alleles of the BAP1 were identified in 51 of the 64 tumors (80%). In all but two patients, these variants were the result of somatic mutations. In the two patients with a germline mutation age at diagnosis was 60 and 41 years, respectively, and thus is not consistently lower than the average age of 60 years of all UM patients with BAP1 mutation.

Conclusion:

We estimate that roughly 3 % of UM patients with M3 tumors might have a BAPCaS. Individual medical and family history of the BAP1 mutation carrier were not apparently distinct from that of the other patients in the cohort suggesting that cancer risk of patients with BAPCaS that were not ascertained via familial aggregation is lower compared to previous estimates. Identification of patients and relatives with BAPCaS is a prerequisite for the development of strategies for early detection and treatment. Implementation of such strategies may improve prognosis of individuals diagnosed with BAPCaS.

For further information please contact: Y. Arjmand Abbassi ([email protected]; [email protected])

Ophthalmologische Onkogenetik/Humangenetik, University Hospital Essen


Key words: heritable predisposition, Uveal Melanoma, BAP1

Poster Nbr. MDEB P2



PRECLINICAL MODELS

Targeting primary ciliogenesis in atypical teratoid/rhabdoid tumors

L. Blümel, K. Kerl, N. Qin, J. Berlandi, K. Thiel, I. Tegeder, A. Jeibmann, E. Paisana, C. Custódia, D. Picard, M. Langini, K. Stühler, F.-D. Meyer, B. Malzkorn, M. C. Liebau, P. D. Johann, S. Erkek, M. Kool, S. M. Pfister, M. C. Frühwald, C. Faria, A. Borkhardt, G. Reifenberger, M. Hasselblatt, M. Remke

Introduction:

Atypical teratoid/rhabdoid tumors (AT/RT) are among the most common malignant brain tumors in infants. Comprehensive genomic studies revealed three distinct molecular subgroups (AT/RT-TYR, -MYC and -SHH). As primary cilia (PC) have already been shown to play a pivotal role in other tumor entities, we aimed to characterize the distribution of PC across AT/RT subgroups and to target primary ciliogenesis in these tumors with dismal prognosis.


We performed immunofluorescence to detect PC in AT/RT primary tumor sections and cell lines. The functional role of PC was investigated in vitro by knockdown of KIF3A. The relevance of primary ciliogenesis in AT/RT biology was further elucidated in vivo using a fly model of SMARCB1 deficiency and an orthotopic mouse model.

Results:

We detected PC in all AT/RT primary tumor sections and cell lines investigated in this study. Notably, we observed a significant subgroup-specific difference in the proportion of PC-positive cells. Specifically, AT/RT-TYR demonstrated the highest percentage of ciliated cells. Knockdown of KIF3A significantly reduced cell proliferation and stem cell properties. Additionally, apoptosis was significantly increased via upregulation of JAK1/STAT1 signaling. In a fly model of SMARCB1 deficiency, concomitant knockdown of several cilia-associated genes resulted in a substantial shift of the lethal phenotype with >20% of flies reaching adulthood. Finally, we demonstrated a significantly prolonged survival in an orthotopic xenograft model upon KIF3A knockdown.

Conclusion:

In conclusion, our results implicate PC as a key feature of AT/RT biology and suggest primary ciliogenesis as a potential therapeutic target, especially in AT/RT-TYR.

For further information please contact: Lena Blümel ([email protected])

Department of Pediatric Oncology, Hematology, and Clinical Immunology Pediatric Neuro-Oncogenomics / AG Remke, University Hospital Düsseldorf


Key words: AT/RT, primary cilia, targeted therapy Poster Nbr.

MDEB P3




Characterizing the impact of metallothionein expression on sensitivity to platin compounds in malignant pleural mesothelioma cell lines –

Knock-down of gene expression as new therapeutic approach?

Sabrina Borchert1, Pia Suckrau1, Michael Wessolly1, Jan Schmeller1, Elena Mairinger1, Balasz Hegedüs2, Thomas Hager1, Thomas Herold1, Robert F. H. Walter1,2, Wilfried E.E. Eberhardt2,3, Jeremias Wohlschlaeger1,4, Clemens Aigner5, Agnes Bankfalvi1, Kurt Werner Schmid1, Fabian D. Mairinger1

Introduction:

Malignant pleural mesothelioma (MPM) is a rare tumor arising from pleural cavities, with dismal prognosis. Platinum-based chemotherapy is often used in a multimodal therapeutic approach. Metallothioneins (MT) are a possible reason for cisplatin resistance, which often leads to early therapy failure or relapse.


The MT gene- and protein-expression of the MPM-cell lines MSTO-211H, NCI-H2052 and NCI-H2452 and the human fibroblast cell line MRC-5, and their sensitivity to cisplatin treatment have been evaluated. Knock-down of MT1A, 1B and 2A expression was induced by RNA interference. MT gene expression was measured using quantitative real-time PCR. Cells state including viability, necrosis and apoptosis were analyzed before and after incubation with cisplatin.

Results:

MT expression levels, especially of MT2A, differs significantly between the analysed cell lines. Additionally, a MT mediated induction of apoptosis via cisplatin was observed, resulting in three different MT based cellular phenotypes.

Conclusion:

Three different MT-based cellular phenotypes could be observed. In the majority of analyzed cell lines, MTs are at least a part of the underlying mechanism of cisplatin resistance. In combination with other biomarkers, MT expression could be used to stratify patients based on the molecular phenotype, saving patients from ineffective, side effected therapies. This hopefully will gain a benefit for patients’ clinical outcome and -management in the near future.

For further information please contact: Sabrina Borchert ([email protected])

Institut für Pathologie, Translational cancer research group /AG Mairinger, University Hospital Essen


Key words: cisplatin resistance, malignant pleural mesothelioma, siRNA, metallothioneins

Poster Nbr. MDEB P4



PRECLINICAL MODELS

Patient-derived lung cancer cell models for prediction of individual therapy response

Cassandra Ho, Paul Stockhammer, Till Plönes, Clemens Aigner, Martin Schuler, Balazs Hegedus, Alexander Schramm

Introduction:

Lung cancer remains the main cause of cancer-related deaths worldwide. It is vital to develop new methods expanding our knowledge on disease biomarkers and improving the ability to predict individual responses to treatment. In this study, we describe establishing patient-derived cancer cell lines in vitro and subsequent development of a mouse avatar model that can retain histopathological features of original patient tumors and predict therapy response.


Human lung cancer samples were processed to produce single cell suspensions. After in vitro passaging, cells (>1 x 106) were mixed in a 1:1 ratio with Matrigel® Matrix and injected into the flank of 5-10 week old NSG mice. Tumors were harvested for further propagation in vitro and in vivo while also collecting material for subsequent molecular analyses.

Results:

An in vitro patient-derived lung cancer cell line was successfully established from a lung cancer harboring a rearrangement of the ALK oncogene. S.c. implantation of these cells in NSG mice proved that they are tumorigenic in vivo.

Conclusion:

We are currently evaluating the response profiles of tumor cells in vitro and in vivo to target inhibition of clinically used ALK inhibitors. We hypothesize that this model will be predictive of individual responses to therapy and will help us to identify and characterize mechanisms of therapy evasion in lung cancer.

For further information please contact: Cassandra Ho ([email protected])

Innere Klinik (Tumorforschung), AG Molekulare Onkologie, University Hospital Essen


Key words: Patient-derived xenograft, NSCLC, lung cancer, ALK

Poster Nbr. MDEB P5



PRECLINICAL MODELS

Investigating the role of MALAT1, a long non-coding RNA, in glioblastoma tumorigenesis

Maike Langini, Nan Qin, Frauke-Dorothee Meyer, Kübra Taban, David Pauk, Daniel Picard, Anja Stefanski, Arndt Borkhardt, Guido Reifenberger, Kai Stühler & Marc Remke

Introduction:

Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) is a long non-coding RNA described to promote cell proliferation, migration and invasion in various cancer entities. MALAT1 is highly conserved among mammals and known to regulate gene expression, post-transcriptionally modify primary transcripts and directly interact with several proteins. This study aims to elucidate the role of MALAT1 in tumorigenesis by characterizing its influence on proteomic signatures in glioblastoma (GBM).

Material and Methods:

Four independent MALAT1 knockdown (KD) cell lines were generated via CRISPRi. In these KD cell lines, MALAT1 dependent changes in phenotypic behavior, protein expression, RNA-protein interactions, and drug sensitivity will be analyzed via cell culture based assays, mass spectrometry (MS), affinity enrichment with MS and RT-qPCR analyses, and high-throughput drug screening, respectively.

Results:

Quantitative MS analysis of KD cell lines and their respective isogenic controls identified significant expression changes in proteins linked to cell migration upon MALAT1 depletion. Preliminary real-time cell migration analysis revealed a reduced migratory propensity upon MALAT1 KD. Furthermore, 15 out of 670 evaluated compounds showed a differential drug response in MALAT1 KD versus control cells. Some of our candidate drugs, including auranofin and disulfiram, are currently examined in clinical trials for GBM.

Conclusions:

Our results reveal that MALAT1 promotes the migratory propensity of GBM cells, contributing to the poor prognosis in this entity. Integrative analyses of proteomic profiles and drug screening data may reveal novel therapeutic vulnerabilities in MALAT1 expressing GBM.

For further information please contact: Maike Langini ([email protected])

Department of Pediatric Oncology, Hematology, and Clinical Immunology Pediatric Neuro-Oncogenomics / AG Remke, University Hospital Düsseldorf


Key words: glioblastoma, MALAT1, long non-coding RNA, mass spectrometry

Poster Nbr. MDEB P6



CLINICAL STUDIES

Heritable predisposition to gastrointestinal stromal tumors: strategies for risk prediction by molecular genetic testing

Lohmann, D. Temming, P.; Bertram, S.; Bauer, S;

Introduction: Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors that presumably originate from of interstitial cells of Cajal. The majority of GIST are caused by gain-of-function type alterations of KIT or PDGFRA. A small subset of “KIT/PDGFRA-wt” patients show loss-of-function variants in SDHA, B, C, or D, loss-of-function of NF1 or gain-of-function alterations of BRAF. Heritable tumor predisposition due to constitutional heterozygosity for a tumorigenic variant is present in some patients, especially those with “KIT/PDGFRA-wt” GIST. Positive family history and/or distinctive clinical features may indicate the presence of such a predisposition. The goal of this ongoing study is to correlate allelic and locus heterogeneity of tumorigenic variants in heritable GIST with variation of phenotypic expression and penetrance.

Materials and Methods: Variant analysis in a panel of cancer related genes is performed on tumor-DNA. Informed consent for analysis of tumor predisposition is obtained after genetic counseling. The constitutional genotype for patient specific tumorigenic variants is determined by targeted analysis. Technical validation of the analysis is performed on tumor-DNA if necessary. Segregation of variant alleles is tested in all consenting adult relatives at risk.

Results: As of now, a heritable predisposition was determined in two families, one segregating a variant of SDHA (NM_004168.3:c.91C>T, p.(Arg31Ter)) and the other of KIT (NM_000222.2(KIT_i001): c.1744_1758dup, p.(Trp582_Arg586dup)). Family testing revealed three clinically non-penetrant relatives (2 and 1, respectively).

Conclusion: If not a chance finding, the numbers of non-penetrance observed here indicate that the frequency of heritable GIST is underestimated. Specifically, ascertainment bias introduced by phenotypic selection has to be avoided. Therefore, in addition to genetic counseling and testing for patients with positive family history and/or distinctive clinical features strategies for exclusion of heritable predisposition are required. A program for cancer screening in individuals at risk will be developed. This must include all tumor entities relevant depending on the genotype (e.g. neuroendocrine cancers such as pheochromocytoma in case of SDHx).

For further information please contact: Dietmar Lohmann ([email protected])

Ophthalmologische Onkogenetik/Humangenetik, University Hospital Essen


Key words: Molecular pathology, heritable predisposition, incomplete penetrance

Poster Nbr. MDEB P7



PRECLINICAL MODELS

HDAC and NFκB antagonists synergistically inhibit growth of MYC-driven medulloblastoma

V. Marquardt, J.Theruvath, D. Pauck, D. Picard, N. Qin, L. Blümel, F. K. Hansen, J. Felsberg, S. Cheshier, G. Reifenberger, A. Borkhardt, T. Kurz, S. Mitra, M. Remke

Introduction:

Medulloblastoma (MB) is the most common malignant pediatric brain tumor and comprises four biological subgroups. MYC-driven tumorigenesis constitutes a hallmark feature underlying Group 3 MB. Metastatic dissemination at diagnosis or recurrence constitutes a major clinical challenge in this aggressive subgroup.


Employing our in-house high-throughput drug screening platform, we performed a primary screen of epigenetic inhibitors (n=78) and a secondary screen of histone deacetylase inhibitor (HDACi, n=20) in various brain tumor cell lines including MB (n=14), glioblastoma (n=14), and atypical teratoid/rhabdoid tumor (n=11).

Results:

We revealed preferential activity of HDACi in MYC-driven MB in our cross-entity approach. Notably, we identified the clinically-established class I specific HDAC inhibitor CI-994 as the most selectively active drug in MYC-driven MB. CI-994 treatment resulted in significantly reduced MYC expression levels, decreased cell viability and induction of apoptosis. Additionally, a screen for synergism with a clinical inhibitor library (n=199) revealed favorable interaction with NFκB inhibition. This finding was further corroborated by RNA sequencing profiling pointing towards NFκB pathway activation upon treatment. Finally, we demonstrated a significantly prolonged survival, a decrease in tumor growth and spinal metastasis in two orthotopic xenograft mouse models of MYC-driven MB.

Conclusion:

In all, our results suggest a MYC-dependent response to class I HDAC inhibition in MB and provide compelling rationale for further development of a novel therapeutic strategy against the primary site and, importantly, the metastatic compartment.

For further information please contact: Viktoria Marquardt ([email protected])

Department of Pediatric Oncology, Hematology and Clinical Immunology Department of Pediatric Neuro-Oncogenomics, AG Remke, University Hospital Düsseldorf


Key words: MYC-driven medulloblastoma, drug screening, HDAC inhibitor

Poster Nbr. MDEB P8



PRECLINICAL MODELS

ctDNA-based therapy monitoring in melanoma patients

Renáta Váraljai, Kilian Wistuba-Hamprecht, Teofila Seremet, Joey Mark S. Diaz, Jérémie Nsengimana, Antje Sucker, Klaus Griewank, Jan-Malte Placke, Peter A. Horn, Nils von Neuhoff, Batool Shannan, Heike Chauvistré, Felix Vogel, Susanne Horn, Jürgen C. Becker, Julia Newton-Bishop, Andreas Stang, Bart Neyns, Benjamin Weide, Dirk Schadendorf, Alexander Roesch

Introduction:

Precision oncology is particularly seeking for novel disease and therapy monitoring technologies that are non-invasive and highly sensitive. Circulating cell-free tumor DNA (ctDNA) is released from all parts of a tumor reflecting the heterogeneous spectrum of specific mutations, especially in systemic disease. Specifically, our project aimed to establish and statistically validate plasma-based assays that allow the dynamic quantitative detection of ctDNA as a biomarker for tumor load and therapy monitoring in melanoma.


We analyzed ctDNA from a large training cohort (n=96) of advanced stage melanoma patients with ddPCR assays for the BRAFV600E, NRASQ61 and TERT promoter mutations. An independent cohort (n=35) was used to validate the clinical utility of ctDNA monitoring under MAPK-targeted or immune checkpoint inhibition.

Results:

In comparison to LDH and S100, elevated plasma ctDNA at baseline presented a significant risk for disease progression in multivariable analysis (HR 7.47, p=0.048). The dynamic changes in ctDNA levels during therapy correlated with treatment response, where increasing ctDNA levels were associated with shorter PFS (e.g. HR 7.28, p<0.0001 for the BRAFV600E assay). Comparison of plasma-based ctDNA analysis with tumor tissue-based amplicon-targeted NGS indicated considerable differences in assay sensitivity and a high level of intra-patient tumor heterogeneity for the NRASQ61 mutation. The detection of plasma NRASQ61 ctDNA in baseline samples of MAPKi-treated BRAFV600E patients significantly correlated with shorter PFS (HR 3.18, p=0.026) and shorter OS (HR 4.08, p=0.014).

Conclusion:

Our results show the potential role of ctDNA measurement as a sensitive therapy monitoring and prediction tool for the early assessment of disease progression in melanoma patients.

For further information please contact: Renata Varaljai ([email protected])

Department of Dermatology, Prof. Dr. med. Alexander Roesch, University Hospital Essen


Key words: ctDNA, liquid biopsy, melanoma Poster Nbr.

MDEB P9



PRECLINICAL MODELS

Cellular heterogeneity drives aggressive tumorigenesis in MYC-driven medulloblastoma

N. Qin1,2,3, M. Langini4, D. Picard1,2,3, E. Paisana5, R. Cascão5, C. Custódia5, F. Meyer1,2,3, A. Stefanski4, K. Stühler4, G. Reifenberger3, A. Borkhardt2, C. Faria5,6, M. Remke1,2,3

Introduction:

Medulloblastoma is the most common malignant brain tumor of childhood and is a genetically heterogeneous disease. Amongst all medulloblastoma subgroups, MYC-amplified medulloblastomas are associated with a particularly poor prognosis as they are commonly metastatic and resistant to standard therapy. However, MYC amplification is restricted to a cellular subpopulation within MYC-amplified tumors. The underlying mechanisms mediating this cellular heterogeneity remain poorly understood. Hypothesis: We hypothesize that a secretome-dependent crosstalk between MYC-amplified and non-MYC-amplified cells shapes an intratumoral microenvironment that promotes medulloblastoma aggressiveness.


We first demonstrate that MYC overexpressing (high-MYC) cells induce proliferation and invasive growth patterns in their isogenic counterparts with low MYC expression (low-MYC) using contacting and non-contacting co-culture systems in three different medulloblastoma cell lines (ONS76, DAOY and UW228-3). Secondly, we demonstrate that exosomes from high-MYC cells promote the migratory propensity of low-MYC cells in vitro. Importantly, we confirmed the pro-tumorigenic interaction of high-MYC and low-MYC cells using two orthotopic medulloblastoma xenograft models. We further demonstrate that low-MYC cells promote tumor angiogenesis in vivo. Using an unbiased proteomic discovery approach and targeted validation by Western blotting, we identified and verified secreted proteins that may mediate this interaction. Rescue experiments validated the relevance of these candidates using functional genomics approaches in vitro, with in vivo validation being currently ongoing.

Conclusion:

We demonstrate that the crosstalk between cellular subclones in MYC-driven medulloblastoma may promote tumor growth, metastasis and angiogenesis. Understanding the underlying secretory signaling networks may elucidate novel therapeutic vulnerabilities in this prognostically poor subgroup of medulloblastoma.

For further information please contact: Nan Qin ([email protected])

Department of Pediatric Neuro-Oncogenomics, AG Remke University Hospital Düsseldorf


Key words: Medulloblastoma, MYC, Heterogeneity, Secretome

Poster Nbr. MDEB P10




Parallel progression of primary colorectal tumors and metastases

Jan Schmeller, Agnes Bilecz, Michael Wessolly, Sabrina Borchert, Elena Mairinger, Clemens Aigner, Thomas Herold, Thomas Hager, Robert F. H. Walter, Fabian Mairinger, Kurt Werner Schmid, Balazs Hegedüs

Introduction:

Currently two major progression schemes are proposed to explain the development of metastasis. The linear model describes the origin of distant metastasis arising from cells of primary tumor spreading after sub clonal evolution via malignant disseminated tumor cells. In contrast, the parallel model proposes an early dissemination of the same precursor clone and independent progression of the primary tumor and metastasis. In order to identify these mechanisms in colorectal cancer (CRC) we compared the mutational profile of corresponding primary and metastatic tumor samples.


Formalin-fixed paraffin embedded (FFPE) tissues from primary (CRC) samples (n=30) and their metastasis (n=30) were obtained from 2 different institutions. Isolated DNA from the aforementioned samples was subjected to targeted amplicon sequencing using the Illumina MiSeq platform. The custom-designed panel covers hotspots and whole coding sequences of 45 cancer related genes.

Results:

In primary tumors 57 mutations were identified of which 9 were unique in the primary. Additionally, in corresponding metastasis 69 mutations were identified, 33 of them unique at the metastatic site. Unique mutations both in primary and metastatic tumor were found in 21 patients.

Conclusion:

In our study, we demonstrated that in 3 out of 30 patients the metastasis progressed parallel with the primary tumor. The impact of different progression models should be taken into consideration for improving current molecular diagnostics and when developing personalized therapeutic strategies.

For further information please contact: Jan Schmeller ([email protected])

Institute of Pathology, Translational Cancer Research, University of Duisburg-Essen, University Hospital Essen,


Key words: NGS; Molecular Pathology, Colon Carcinoma, Metastasis




PRECLINICAL MODELS

Identification of novel therapeutic approaches for medulloblastoma

Kübra Taban, David Pauck, Viktoria Marquardt, Arndt Borkhardt, Guido Reifenberger, Thomas Beez, M. Remke

Introduction:

Medulloblastoma (MB) is the most common malignant brain tumor in children and is frequently metastatic at diagnosis. Non-infants with MB are treated with surgery, radiation and multi-agent chemotherapy, leaving most survivors with devastating long-term side-effects as a consequence. One of the four consensus MB subgroups is the MYC-driven group 3, which is associated with the worst prognosis. Thus, novel and more effective targeted therapeutic approaches are urgently required.


Our high-throughput drug screening (HTS) pipeline utilizes three automated pieces of equipment: The D300e Digital Dispenser dispenses compounds on 384- or 1596-well microtiter plates in a randomized manner. Our compound library is composed of clinically-applicable inhibitors (conventional chemotherapeutics and antitumoral inhibitors in phase I – IV evaluation; n=650). Cell suspensions are then dispensed into microtiter plates using the MultiDrop Combi. Cell viability changes are detected using the CellTiter-Glo assay after a 72h incubation period. The luminescence signal is measured using the Spark multimode microplate reader. Candidate compounds with entity- or subgroup-specific activity are validated using functional genomics approaches.

Conclusion:

Our HTS pipeline has identified over 10 inhibitors, which significantly reduce cell viability in MYC-driven (n=7) compared to non MYC-driven MB (n=4). Furthermore, over 20 inhibitors were identified with significant reduction of cell viability in MB (n=11) compared to other brain tumor entities (n=26). In conclusion, our HTS approach revealed novel therapeutic vulnerabilities for MB, which are currently validated in vitro and in vivo.

For further information please contact: Kübra Taban ([email protected])

Pediatric Oncology, Hematology, and Clinical Immunology, AG Remke, University Hospital Düsseldorf


Key words: Medulloblastoma, high-throughput drug screening (HTS)




CLINICAL STUDIES

The Impact of the type of Predisposing RB1 Variants on incidence of Malignancies

Petra Temming1,2,3, Isabel Hülsenbeck3, Norbert Bornfeld4,3, Wolfgang Sauerwein5, Karl- Heinz Jöckel6, Dietmar R. Lohmann2,3

Introduction:

Survivors of heritable retinoblastoma carry a high risk to develop other malignancies later in life. The incidence of these second primary malignancies (SPM) is significantly raised after external beam radiotherapy (EBRT). We aimed to analyze the impact of the type of the predisposing RB1 gene variant on the incidence of SPM with and without previous irradiation.


From 1940 to 2008, 655 national patients were treated for heritable retinoblastoma at the German referral center. Complete information on second malignancies until 2012 and data on constitutional RB1 variant were available for 317 patients (48.3%).

Results:

SPM occurred in 51 of 317 survivors of heritable retinoblastoma. After irradiation, the cumulative incidence ratio (per 1,000 person years) of SPM was 10.7 (95% confidence interval 7.7-14.5) and was not influenced by type of constitutional RB1 mutations. In non-irradiated retinoblastoma survivors, the cumulative incidence ratio of SPM was lower compared to the irradiated patients (IR 3.9 [1.8-7.1]; p< 0.005). Without previous irradiation, SPM were only observed in patients with high penetrance RB1 variants. No SPM was reported in survivors with somatic mosaicm of RB1 gene or in survivors with low penetrance RB1 variant. The type of tumors in non-irradiated heritable retinoblastoma survivors were diverse and comprised of three soft tissue sarcoma, one hematological malignancy, three mamma carcinoma, one bronchial carcinoma, one melanoma and one brain tumor.

Conclusion:

The influence of the type of predisposing RB1 variant on the incidence of SPM in our cohort was only evident without previous radiotherapy treatment. After external beam radiotherapy, all survivors of heritable retinoblastoma were at risk for second cancers regardless of the constitutional RB1 genotype.

For further information please contact: Petra Temming ([email protected])

Department of Pediatric Hematology and Oncology, Retinoblastoma, Eye Oncogenetics Research Group, University Hospital Essen


Key words: tumor predisposition, retinoblastoma, sarcoma, RB1





Proteogenomics reveals distinct biological pilocytic astrocytoma subgroups

Daniel Picard, Jörg Felsberg, Maike Langin, David Pauck, Viktoria Marquardt, Frauke Meyer, Sarah Göbbles, Anja Stefanski, Kai Stühler, Lucia Roque, Arndt Borkhardt, Guido Reifenberger, Cláudia Faria and Marc Remke

Introduction:

Pilocytic astrocytoma (PA) is the most common pediatric brain tumor. Aberrant MAPK signaling drives PA formation, typically mediated by BRAF alterations. While five-year overall survival rates exceed 95%, incompletely resected tumors recur frequently despite treatment. Therefore, we used proteogenomics to discern the biological heterogeneity of PA to improve classification of this tumor entity and identify novel therapeutic targets.


Our proteogenomics approach utilizes RNA sequencing, methylation and LC/MS-based proteomic profiling. Similarity Fusion Network (SNF) reveals the biological heterogeneity of PA and integrative genomics dissects aberrant pathway activation in biological subgroups. Lastly, we perform drug screening to evaluate selective therapeutic activity of 200 anti-cancer drugs in PA culture models.

Results:

PAs segregate into two groups with distinct clinical and molecular features. Age is significantly associated with the SNF groups. BRAF fusions were predominantly observed in Group 1 while Group 2 PA largely harbored other alterations in the MAPK pathway. Geneset enrichment analyses reveal genesets involved in ion channel activity, neurotransmitter signaling and cellular respiration, whereas immune response signatures, many SYK-related, are associated with Group 1. Confirming this analysis, the SYK inhibitor R788 was specifically active in Group 1, and less active in other primary models (n=13).

Conclusion:

In summary, our approach reveals important biological heterogeneity with novel therapeutic targets emerging in PA. These biological insights may improve biological classification and reveal novel therapeutic targets specifically useful for non-resectable tumors with high risk of progressive disease.

For further information please contact: Daniel Picard ([email protected])

Pediatric Neuro-Oncogenomics, AG Remke, University Hospital Düsseldorf


Key words: Proteogenomics, Pilocytic Astrocytoma, Oncology




CLINICAL STUDIES

Impact of RAS mutation subtype on clinical outcome – A cross-entity comparison of patients with advanced non-small cell lung cancer and

colorectal cancer

Marcel Wiesweg, Stefan Kasper, Karl Worm, Thomas Herold, Henning Reis, Linda Sara, Martin Metzenmacher, Annalena Abendroth, Kaid Darwiche, Clemens Aigner, Heiner H. Wedemeyer, Fabian A. Helfritz, Martin Stuschke, Brigitte Schumacher, Peter Markus, Andreas Paul, Sven Rahmann, Kurt W. Schmid, Martin Schuler

Introduction: Mutated RAS onco-proteins are key drivers across many cancers. The distribution of somatic RAS mutations varies between cancer entities. Retrospective analyses have associated some RAS mutations with distinct clinical outcomes.


We studied genomically and clinically annotated, prospectively recruited cohorts of patients with RAS-mutated metastatic lung cancer and colorectal cancer.

Results:

Mutational spectra were compared to predictions derived from analyzing the mutagenic impact at the genome level. We found concordance of predicted signatures with those actually observed in our patients. Thus composition of the functionally active RAS mutational subtypes is primarily determined by the mutagenic context. RAS-comutations were enriched in tumors harboring class 2/3 BRAF mutations, highlighting the functional dependency of some mutated BRAF isoforms on RAS. We established a probabilistic model for cross-entity comparison of the prognostic impact of specific RAS mutational subtypes. The resulting prognostic clusters showed largely consistent clinical categorizations in both entities. This suggests mutant subtype-specific functional properties leading to similar clinical effects.

Conclusion:

Our findings provide a framework for risk stratification of specific RAS mutations across several cancer entities, which is required to guide analysis of clinical findings in patients treated with direct RAS inhibitors or agents targeting downstream pathways.

For further information please contact: Marcel Wiesweg ([email protected])

Department of Medical Oncology, University Hospital Essen


Key words: Lung Cancer, colorectal cancer, RAS, BRAF Poster Nbr. MDEB P15



The clinical relevance of indirect MYC inhibitors for personalized T-ALL treatment

Ahlert, Heinz; Bhatia Sanil; Sönnichsen, Melf; Remke, Marc; Borkhardt, Arndt; Hauer, Julia

Introduction:

Therapy refractory and relapsed T-ALL patients have a very poor outcome. Many T-ALL patients need to undergo SCT and therefore targeted therapies with low toxicity profile are urgently needed. The transcription factor MYC is a potent driver of T-ALL and is therefore excellently suited as a therapeutic target. So far, the inhibition of MYC can only be achieved indirectly or by targeting synergistic pathways.


Seven T-ALL cell line models and one T-cell lymphoma model were profiled at mRNA and protein levels, and then screened in a high throughput drug screening including diverse phase I - III inhibitors (n=180). PBMCs and sorted healthy T-cells served as controls. Synergy studies were performed with preselected compounds in an 11 by 11 matrix.

Results:

We profiled the T-ALL models with a specific interest for genes implicated in MYC regulation. Four models harbor PTEN mutations (mut), whereas the other four were PTEN wildtype (wt). The loss of PTEN activity leads to increased AKT phosphorylation (pAKT). We observed higher MYC expression in three out of four PTEN mut models. To stratify PTEN mut and wt models according to their therapeutic response to MYC inhibition, we used 180 compounds covering 8 major MYC regulatory pathways. PTEN mut and wt showed a distinct drug response pattern. Blocking PI3K, a positive MYC regulator, had a strong cytotoxic effect, especially in PTEN mut models. Synergy studies of PI3K inhibitors and indirect MYC inhibitors enhanced cytotoxic effects.

Conclusion:

Tumor suppressor protein PTEN is an important MYC regulator. The use of PI3K inhibitors is a promising target in PTEN mut/pAKT T-ALL patients, due to the high dependence on PI3K. Furthermore, parallel targeting of two main MYC regulators increases the cytotoxicity dramatically.

For further information please contact: Heinz Ahlert ([email protected])

Department of Pediatric Oncology, Hematology and Clinical Immunology, University Hospital Düsseldorf

1st Floor Key words: T-ALL, Targeted Therapy, High Throughput Drug Screen, MYC, PTEN

Poster Nbr. MTT P1



Functional Characterization of the Ubiquitin-Proteasome-System in Pancreatic Ductal Adenocarcinoma

F. Lang, S. Lueong, J. Hoheisel, S. Liffers, O. Karpiuk, F. Bassermann, J. T. Siveke

Introduction:

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive neoplasm with insufficient response to most conventional treatments and there is an urgent need to identify new therapeutic options.

The ubiquitin-proteasome-system (UPS) emerges as a prime therapeutic target, since alterations of UPS proteins promote tumor progression and are increasingly found in various cancers. Limited data exist about essential UPS proteins in PDAC, thus we focus on the identification of fundamental UPS proteins in progression and maintenance.

Methods:

We performed a CRISPR/Cas9 based knock out screen of 200 different UPS proteins in PDAC cell lines using an established sgRNA library for different ligases and deubiquitinases (FBOX, DUB). Furthermore, large microarray data sets from resected PDAC (41 normal-, 59 chronic pancreatitis- and 200 tissue samples) and 60 patient-derived xenografts underwent a candidate screening workflow to identify UPS proteins upregulated in PDAC. Validation is performed by qRT-PCR and immunohistochemistry (IHC) in cell lines and tissue microarrays respectively.

Results:

We analyzed the knock out screen in two PDAC cell lines and provide first candidates, which are validated in further cell lines and PDAC samples. Candidate screening of the microarray data identified 15 proteins upregulated in PDAC vs. normal pancreas. Based on multiparametric selection criteria, three ligases and deubiquitinases were identified and underwent validation in independent PDAC cohorts, expression analysis and IHC in PDAC tissue.

Conclusion:

The combination of both applied methods represents a multi-level strategy for identifying prime candidates of the UPS system for novel targeting approaches in PDAC.

For further information please contact: Franziska Lang ([email protected])

DKTK Division of Solid Tumor Translational Oncology, University Hospital Essen

1st Floor Key words: Ubiquitin-Proteasome System, Pancreatic Ductal Adenocarcinoma, CRISPR Cas9, Knock out screen

Poster Nbr. MTT P2



In newly established malignant pleural effusion derived anaplastic thyroid cancer cell line PD-L1 expression is strongly increased by HDAC

inhibitor treatment

Luca Hegedus, Dominika Rittler, Tamás Garay, Paul Stockhammer, Ildikó Kovács, Balázs Döme, Kurt W. Schmid, Dagmar Führer, Clemens Aigner, Balázs Hegedűs

Introduction:

Anaplastic thyroid cancer is a deadly disease causing around 30% of thyroid cancer related death. Beside surgery pre- and postoperative radiotherapy and chemotherapy can be offered as treatment for patients and for metastatic or unresectable ATC with BRAFV600E mutation recently

BRAF and MEK inhibitor combined treatment was approved by the FDA. However further preclinical models and novel combinations are necessary to improve patient survival.


We established a new anaplastic thyroid cancer cell line from the pleural effusion sample of a 69 year old male patient. The cells carry mutations in their BRAF gene (V660E) and their TERT promoter region.

Results:

We found that the cells have strong migratory activity in vitro and highly metastatic in vivo. After intrapleural injection in immunocompromised mice within two weeks widespread pleural carcinosis developed and the cells invaded the lung, the skeletal muscle and the heart. Combined treatment with BRAF and MEK inhibitors reduced the proliferation of the cells and significantly inhibited cell migration. Treatment with histone deacetylase (HDAC) inhibitors initiated cell cycle arrest in the G2/M phase and strongly induced PD-L1 expression of the cells. Paclitaxel-cisplatin chemotherapeutic treatment could reduce the viability of the cells but it alone did not increased PD-L1 expression. However in combination with HDAC inhibitor treatment the elevation of PD-L1 expression was also present. Similar results were obtained with anaplastic thyroid cancer cell line BTH-101.

Conclusion:

Our results show that combination of standard chemotherapy with HDAC inhibition may potentiate anaplastic thyroid cancer cells for immunotherapy. Novel clinically annotated preclinical models are invaluable tools to test experimental therapeutic modalities.

For further information please contact: Luca Hegedus ([email protected])

Department of Thoracic Surgery, Translational Thoracic Research Laboratory, Ruhrlandklinik, University Hospital Essen

1st Floor Key words: Anaplastic thyroid cancer, BRAF mutation, immune checkpoint, HDAC inhibition, pleural effusion

Poster Nbr. MTT P3



SCIENCE

Pharmacologic LSD1 inhibition preserves human granulocytic while expanding monocytic progenitors

Karlotta E. Kahmann1,2, Stefanie Kesper1, Marco Luciani1, Michael Möllmann1, Ulrich Dührsen1, Hugh Rienhoff3, Joachim R. Göthert1

Introduction:

Histone modifications such as methylation are severely perturbed in myeloid leukemias. We previously demonstrated the central role of the lysine-specific histone demethylase 1 (LSD1) in normal murine hematopoiesis (Sprüssel et al, Leukemia 2012). Remarkably, in human acute myeloid leukemia (AML) LSD1 expression is de-regulated and therefore represents an attractive AML therapeutic target. In fact, first generation LSD1 inhibitors were shown to induce AML cell differentiation and apoptosis in combination with all-trans-retinoic acid (ATRA) exposure. However, the exact mechanisms-of-action and hematopoietic side effects of LSD1 inhibition in normal human hematopoiesis and AML are not yet fully understood.


We studied the impact of the novel LSD1 inhibitor IMG-7289 on the colony forming unit (CFU) potential of human CD34+ progenitor in vitro. Furthermore, IMG-7289 anti-AML activity was investigated with AML cell lines.

Results:

LSD1 inhibition with IMG-7289 fostered monopoiesis while perturbing erythro- and granulopoiesis. LSD1 inhibition in combination with ATRA completely blocked terminal human hematopoietic differentiation. However, in re-plating experiments IMG-7289-treated progenitors showed strikingly increased CFU-activity compared to carrier control-treated progenitors. Finally, IMG- 7289 significantly inhibited the growth (IC50 29 nM) and leukemic colony formation of the Kasumi-1 AML cell line.

Conclusion:

Taken together, pharmacologic LSD1 inhibition interferes with normal human hematopoietic differentiation while preserving normal progenitor potential. IMG-7289 displays AML cytotoxicity at nanomolar concentrations in vitro.

For further information please contact: Karlotta Kahmann ([email protected])

Departement of Hematology, AG Göthert, [email protected], University Hospital Essen

1st Floor Key words: Poster Nbr.

MTT P4



Metabolic profiling and targeting of Pancreatic Ductal Adenocarcinoma

Sinan Karakaya, Sven T. Liffers, Smith Lueong, Phyllis Fung-Yi Cheung, Wei Yang, Amy Harms, Thomas Hankemeier, Stephan Hahn, Marija Trajkovic-Arsic and Jens T. Siveke

Introduction:

The dismal prognosis and lack of effective therapies in pancreatic ductal adenocarcinoma (PDAC) requires novel targeting strategies. By identifying metabolic differences among PDAC subtypes, quasi-mesenchymal (QM) and classical, new metabolic-based targeting strategies are possible.


Subtype-specific metabolic peculiarities of PDAC are analyzed in different model systems via: metabolite profiling (LC-MS), gene expression analysis (RNA sequencing, Illumina HT12 microarray), seahorse functional assays and immunohistochemistry.

Results:

Gene expression analysis of the PDAC commercial cell lines and PDX samples show higher expression of glycolytic genes in QM PDAC samples while FA-lipid metabolism genes are higher in classical samples. Targeted metabolite profiling indicates that Fatty Acid-lipid metabolism is active in classical subtype. Seahorse mito fuel flex test suggested that QM cell lines use glucose to fuel mitochondria whilst classical cell lines rely on fatty acids to fulfill the basal energy demand. Immunohistochemistry results on patient FFPE samples confirm upregulation of glycolytic markers in QM samples.

Conclusion:

We showed that lipid metabolism is a potential hallmark of classical subtype, whereas higher glycolytic rate is a feature of QM subtype and these differences are conserved in different PDAC models.

For further information please contact: Sinan Karakaya ([email protected])

Translational Solid Tumor Oncology, University Hospital Essen

1st Floor Key words: PDAC, metabolism, cancer, onco-metabolites Poster Nbr.

MTT P5



SCIENCE

Cisplatin induces CMGC kinases in platin-sensitive MPM cell lines: new therapeutic options for a severe disease?

Sabrina Borchert, Pia Suckrau, Michael Wessolly, Jan Schmeller, Elena Mairinger, Balasz Hegedüs, Thomas Hager, Thomas Herold, Wilfried E.E. Eberhardt, Jeremias Wohlschlaeger, Clemens Aigner, Agnes Bankfalvi, Kurt Werner Schmid, Fabian D. Mairinger, Robert F. H. Walter

Introduction:

Malignant pleural mesothelioma (MPM) is a rare, predominantly asbestos-related and biologically highly aggressive tumor leading to a dismal prognosis. Multimodal therapy consisting of platinum-based chemotherapy is the treatment of choice. Platin-compounds resulted in a response rate of merely 6-14% and a median survival of below 7 months. The reasons for the rather poor efficacy of platinum compounds remain largely unknown.


Three different MPM-cell lines MSTO-211H, NCI-H2052 and NCI-H2452 and the human fibroblast cell line MRC-5, representing each one sensitive, intermediate and resistant tumor as well as a sensitive healthy control. Kinase activity before and after treatment with cisplatin have been evaluated using the PamGene PamStation®12 for kinase activity profiling with the appertaining STK and PTK Pamchip, including a total of 340 most important kinases. Cells state including viability, necrosis and apoptosis were analyzed before and after incubation with cisplatin.

Results:

Overall, tyrosine kinase activity shows decrease during platin-treatment in all four cell lines. Additionally, strong activation of CMGC kinases could be observed in platin-sensitive cells. These include but are not limited to the different CDKs as well as MAPKs.

Conclusion:

Kinase activation seems to play a crucial role in cellular response to platin-based chemotherapeutic regimens. In particular, CMGC kinases show selective activation in sensitive tumor cells. Combining inhibitors against these markers may improve clinical and pathological practice, finally leading to a patients’ benefit by an enhanced clinical management.

For further information please contact: Sabrina Borchert ([email protected])

Institut für Pathologie, Translational cancer research group /AG Mairinger University Hospital Essen

1st Floor Key words: cisplatin resistance, malignant pleural mesothelioma, kinase activity

Poster Nbr. MTT P6



Comprehensive molecular characterization of a pancreatic cancer PDX cohort for subtype-specific therapy approaches

Sven-T. Liffers1,2, Smiths S. Lueong1,2, Svenja Mergener1,2, Jan Forster5, Heiner Wolters8, Richard Viebahn9, Andrea Tannapfel7, Waldemar Uhl6, Stephan A. Hahn3,4, Jens T. Siveke1,2

Introduction:

Pancreatic cancer is the third leading cause of cancer-associated death due to high intrinsic and acquired resistance. To identify potential subgroups and targets and to recapitulate the genomic, transcriptomic and metabolic landscape of PDAC, we generated and characterized a patient-derived xenograft library based on 48 resected primary pancreatic cancers.


PDX were analyzed by targeted sequencing, RNAseq and gene expression profiling using human HT-12 expression beadchips as well as methylome EPIC arrays (Illumina). Based on the mRNA expression analysis, the PDX clustered into two subgroups, namely the classical and quasi-mesenchymal subtype. Our sequencing data displayed an alteration of the KRAS gene in 92% of cases followed by CDKN2A (81%), TP53 (69%) and SMAD4 (42%). Notably, SMAD4 status was significantly different between both groups. Furthermore, genes related to the chromatin remodeling process and DNA damage response showed an alteration of at least one of the analyzed genes in 71% of the analyzed cases.

Results:

In addition, we derived 2D and 3D cultured cells from selected PDX cases. The reimplantation of these cells into nude mice confirmed that the tumorigenic phenotype was maintained during the in vitro culture. Histological and mRNA expression analysis confirmed a high correlation between PDX tumors and low passage cultured cells, supporting the usage for high-throughput drug screening experiments.

Conclusion:

Our PDX library offers a platform to explore in-depth changes on the genomic and transcriptomic level in dependence of different explorative treatment regimes. Further, it enables the opportunity for drug screening in 2D and 3D cell lines and xenograft setup using PDAC samples of known clinical history to identify new vulnerabilities of PDAC cells.

For further information please contact: Sven-T. Liffers ([email protected])

Translationale Onkologie Solider Tumore, University Hospital Essen

1st Floor Key words: PDAC, Subtype, PDX Poster Nbr.

MTT P7



Bortezomib sensitivity is tissue dependant and high expression of the 20S proteasome precludes good response in malignant pleural

mesothelioma

Walter, Robert Fred Henry; Sydow, Saskia Roxanne; Mairinger, Elena; Vollbrecht, Claudia; Werner, Robert; Berg, Erika; Schmeller, Jan; Wessolly, Michael; Borchert, Sabrina; Kollmeier, Jens; Christoph, Daniel Christian; Mairinger, Thomas; Wohlschlaeger, Jeremias; Schmid, Kurt Werner; Mairinger, Fabian Dominik

Introduction:

Bortezomib is an approved proteasome inhibitor for the treatment of certain lymphoma subtypes. Clinical trials use bortezomib alone or in combination with cisplatin failed to improve outcome in patients with malignant pleural mesothelioma (MPM).


84 patients with MPM were analyzed for their mRNA expression levels of proteasomal subunits via qPCR. Additionally, 4 mesothelial cell lines and 1 fibroblast cell line were treated with bortezomib and/or cisplatin. Apoptosis, cell viability/senescence and necrosis were measured by fluorescence- and luminescence-based assays after 0, 6, 12, 24, 48 and 72 h. Enzyme activity of proteasomal subunits was assessed via fluorescent-based, functional enzyme activity assays.

Results:

MPM presented with elevated expression of proteasomal subunits compared to benign control tissue (all p<0.001). Only two MPM cell lines with comparably low proteasome activity of two catalytic domains (PSMB2 and PSMB5) show response to the treatment with 50 nM and 100 nM bortezomib better than to cisplatin (MRC-5, NCI-H2052). MSTO-211H responded to cisplatin only, whereas the other two cell lines were considered therapy resistant (Met-5A, NCI-H2452)

Conclusion:

MPM present with high expression of proteasomal subunits, but two clinical trials investigating bortezomib in MPM failed. Bortezomib sensitivity seems to be tissue dependant and bortezomib induced apoptosis sufficiently in MPM cell lines with low proteasome activity only. Biomarker based stratification of patients could have improved both clinical trials.

For further information please contact: Fabian Dominik Mairinger ([email protected])

University Hospital Essen, Institute of Pathology Translational Cancer Research Group, University Hospital Essen

1st Floor Key words: proteasome, pleural mesothelioma, mRNA expression, therapy

Poster Nbr. MTT P8



Tumor cell cytoplasmic metallothionein expression associates with differential tumor immunogenicity and prognostic outcome in high

grade serous ovarian carcinoma (HGSOC)

Mairinger, Elena; Buderath, Paul; Borchert, Sabrina; Mach, Pawel; Wessolly, Michael; Westerwick, Daniela; Walter, Robert Fred Henry; Schmeller, Jan; Kimmig, Rainer; Jasani, Bharat; Schmid, Kurt Werner; Bankfalvi, Agnes; Mairinger, Fabian Dominik

Introduction:

Intracellular zinc homeostasis is mainly regulated by metallothioneins (MTs). In vivo, zinc deficiency alters the number and function of a variety of immune cells. Especially T cell function and balance between their differentiation forms are particularly susceptible to changes in zinc status. The aim of the present study was to investigate the possible role of metallothionein mediated immune response and its association with prognostic outcome in ovarian cancer.


A retrospective study was conducted on a clinically well characterized cohort of 24 patients with HGSOC. Gene expression patterns for anti-cancer immunogenicity-related targets were performed using the NanoString nCounter platform for digital gene expression analysis, consisting of 770 targets as well as 30 reference genes. Tumor associated immunohistochemical MT protein expression was evaluated microscopically using semi-quantitative IHC scoring.

Results:

MT immunoexpression was detected in 43% of all HGSOC samples. In our cohort, its expression showed a significant association to prolonged PFS and OS. Furthermore, T cell receptor signaling gene signature showed a strong activation in MT positive tumors. Activated downstream signaling cascades resulting in elevated IFNγ expression as well as a higher expression pattern of perforin and several granzymes could be detected, suggesting an acute, targeted anti-cancer immune response.

Conclusion:

MT overexpression is associated with molecular characteristics of an anti-cancer immune response and is a strong prognostic marker in HGSOC. The observed immune cell activation associated with tumor MT expression comprises but is not limited to T cells and NK cells.

For further information please contact: Elena Mairinger ([email protected])


1st Floor Key words: metallothionein, ovarian cancer, biomarkers, immune system

Poster Nbr. MTT P9



SCIENCE

Epigenetic Targeting in Patient-Derived Organoids from Uveal Melanoma and Clear-Cell Renal Cell Carcinoma

S. Mergener, M. Zeschnigk, H. Reis, N. Bechrakis, B. Hadaschik, J.-T. Siveke and S. Peña-Llopis

Introduction:

BRCA1-associated protein 1 (BAP1) is a nuclear deubiquitylase involved in the transcriptional regulation of genes that take part in several different cellular processes, including epigenetic regulation. Inactivating mutations of BAP1 are strongly correlated with increased tumor aggressiveness and a higher risk of metastasis, leading to poor patient survival. BAP1 has been found to be mutated in 80% of metastatic uveal melanomas (UM) and 14% of renal cell carcinomas and defines a new subtype of clear-cell renal cell carcinoma (ccRCC) with poor prognosis.

Results:

The aim of this project is the identification of therapies that specifically affect BAP1-mutated cancer cells. Furthermore, we attempt to establish 3D cultivation of patient-derived organoids from fresh UM and ccRCC tissue as a new preclinical model. After validation of the ability to mirror the primary tumors in terms of histology, molecular genetics (mutations, gene expression and chromosomal alterations) and individual drug responses, we want to screen primary organoids as well as patient-derived cell lines with a panel of different epigenetic inhibitors to analyze the effects of the respective drugs alone or in combination with other therapies in the context of the mutational status of BAP1.

Conclusion:

These new preclinical models could provide a platform for predicting drug responses in a personalized fashion and monitoring individual tumor development.

For further information please contact: Svenja Mergener ([email protected])

Translational Oncology in Solid Tumors, AG Peña-Llopis (Translational Genomics in Solid Tumors), University Hospital Essen

1st Floor Key words: Uveal Melanoma, Clear-Cell Renal Cell Carcinoma, Organoids, Epigenetics, Drug Screening Experiments

Poster Nbr. MTT P10



A role for acid ceramidase in hematopoietic stem and progenitor cellmobilization

Eyad Naser, Joachim Göthert, Maher Hanoun, Alexander

Introduction:

The aim of this study is to investigate the role of sphingolipid signaling in hematopoietic stem and progenitor cell HSPC mobilization and to improve the outcome of standard clinical mobilizing protocols with G-CSF and AMD3100 by targeting enzymes in the sphingolipid pathway.


C57BL/6 mice lacking the expression of acid ceramidase (AC-/-), AC heterozygous (AC+/-), AC overexpressing mice (CAG-Asah1tg) and their wt-littermates were injected s.c. with rhG-CSF 250μg/kg/d for 5 days. On day 5, peripheral blood (PB), spleen and bone marrow (BM) were collected. PB was analyzed phenotypically, functionally in vitro (CFU-C) assay, and in vivo by transplanting PB from G-CSF-treated CD45.2 donors and CD45.1 BM into lethally irradiated CD45.1 mice. PB CD45.2 chimerism was then investigated at regular intervals in the recipients.

Results:

AC-/- and AC+/- mice exhibit significantly reduced, but CAG-Asah1tg significantly increased lineage- Sca-1+ c-kit+ population, CFU-C and CD45.2 chimerism in recipients, respectively. These changes are independent of BM CXCL12 levels.

Conclusion:

The efficiency of G-CSF-mediated HSPC mobilization correlates with AC expression and activity. AC regulates HSPC mobilization independently of BM CXCL12 levels via yet unknown mechanisms. A possible therapeutic benefit with rhAC in “poor mobilizer” patients with autonomic neuropathy is being investigated in mouse models.

For further information please contact: Eyad Naser ([email protected])

Institut für Molekularbiologie, AG Carpinteiro, University Hospital Essen

1st Floor Key words: - Poster Nbr.

MTT P11



Mitochondria dysfunction in metastatic lung adenocarcinoma: a progression specific therapeutic target

Chen-Hua Chuang, Kristina Ueffing, Madeleine Dorsch, Monte Winslow and Barbara Grüner

Introduction:

Lung cancer is a prevalent and lethal cancer type leading to more deaths than the next four major cancers combined. Metastatic cancer spread is responsible for most cancer deaths but the cellular changes that enable cancer cells to leave the primary tumor and establish metastases remain poorly understood. To identify novel anti-metastatic targets, we performed a genome-scale shRNA screen in metastatic and non-metastatic cancer cells.


Cell lines representing the non-metastatic (TnonMet) and metastatic states (Met) of Non Small Cell lung cancer were generated from our genetically-engineered mouse models. The cells were used for an in vitro genome-scale pooled lentiviral-shRNA library screen leading to identification of genes specifically lethal to metastatic cells. Genes identified with metastasis specific lethality were further analyzed using various in vitro and in vivo assays.

Results:

Met and TnonMet cells were treated with different compounds inhibiting mitochondrial transcription or translation, confirming a Met-specific lethality. In further experiments Met cells showed reduced spare respiratory capacity and lower mitochondria membrane potential both in vitro and in vivo, indicating higher susceptibility to mitochondria-targeting therapy. Electron microscopy of primary tumors and metastases derived from the autochthonous lung cancer mouse model revealed irregular mitochondrial structure in metastases. Furthermore, treating mice with established subcutaneous tumors with phenformin, inducing lactic acidosis, significantly reduced the number of metastases in the lungs of the treated mice compared to control.

Conclusion:

Analysis of metastatic and non-metastatic lung cancer cells and tissues uncovered that mitochondria-targeted therapy is specifically lethal to metastases.

For further information please contact: Kristina Ueffing ([email protected])

Department of Medical Oncology, AG Grüner / Molekulare Tumorpathologie, University Hospital Essen

1st Floor Key words: Lung cancer, metastasis, mouse models, mitochondria, pooled lentiviral-shRNA library screen

Poster Nbr. MTT P12



GENERATION AND DEVELOPMENT OF A NOVEL DUAL BET/HDAC INHIBITOR WITH PROMISING ANTI-TUMOR PROPERTIES

X. ZHANG, T. ZEGAR, R. LUCAS, T. WEISER, J. HENCK, S. JOHNSEN, S. KNAPP, J.T. SIVEKE

Introduction:

Transcriptional networks and chromatin regulatory mechanisms mediate oncogenic transcriptional programs and cellular identity, both of which have been linked to therapy resistance. BET and HDAC proteins are central regulators of chromatin structure and transcription and combined BET and HDAC inhibition is synergistic in tumor models of various malignancies. Thus, the development of dual BET/HDAC inhibitors combined in a single small molecule is a new strategy to minimize liabilities of combination approaches and potentially increase the therapeutic window.

Results:

We generated a small molecule TW9 with dual BET and HDAC inhibitory moieties by combining backbones of JQ1 and CI994. TW9 showed inhibition of BRD4 and HDACs in similar dose ranges using FRET-based assays. Squamous differentiation was induced more efficiently by TW9 compared to JQ1 in nut midline carcinoma cell lines. MYC protein levels were reduced and histone acetylation levels increased in a dose-dependent manner in various PDAC cell lines using TW9 and were comparable to the effects of JQ1 and CI994 respectively. Cell viability assays showed more pronounced anti-proliferative effects for TW9 compared to JQ1, CI994 or the combination of both. Notably, long-term suppression of proliferation was in particular effective using short-time or single dose treatment of TW9 supporting low-dosing strategies. First xenograft experiment with PDAC cells showed a suppressed tumor growth compared to vehicle treated mice. Further in vivo experiments are currently ongoing.

Conclusion:

In summary, we report on the generation and characterization of a novel dual BET/HDAC inhibitor with promising anti-tumor properties that will undergo further evaluation for potential clinical applicability.

For further information please contact: Tim Zegar ([email protected])

DKTK Division of Solid Tumor Translational Oncology, University Hospital Essen

1st Floor Key words: epigenetics, BETi, HDACi, dual inhibitor Poster Nbr.

MTT P13


CANCER GENOME SEQUENCING AND PROTEOME ANALYSIS

Microphaser – Small scale phasing for neoantigen discovery

Jan Forster, Johannes Köster

Introduction:

One of the biggest challenges in cancer immunotherapy lies in the discovery of functional neoantigens. A crucial step in neoantigen prediction is the generation of a cancer-specific neo-peptidome. Current approaches mostly rely on incorporating somatic variants into the human reference. In the light of precision oncology, it seems promising to further include patient-specific germline variants as well as peptide phasing to create a more specific and accurate search space for neoepitope candidates. Therefore, we introduce Microphaser, a tool for fast small-scale phasing of cancer peptides.


Microphaser generates all peptides of typical epitope length (9 amino acids) while incorporating germline and somatic mutations and counting reads supporting each peptide. Tumor-specific neopeptides, which contain at least one somatic variant are taken as candidates for neoantigen prediction, all other peptides are used as background for filtering self-similarity in neopeptides.

Results:

On a dataset of 17 malignant pleural mesothelioma patients, we could identify several neoantigen candidates which were not found using other prediction pipelines. Futhermore, we were able to infer clonal and subclonal frequencies of possible neoantigenes.

Conclusion:

Phasing somatic variants and incorporating germline variants increases the accuracy of the patient-specific (neo)peptidome and might improve neoantigen discovery.

For further information please contact: Jan Forster ([email protected])

University Hospital Essen

2nd Floor Key words: phasing, cancer immunotherapy, precision oncology

Poster Nbr. CGPA P1



A latent variable model for structural variant calling in tumor/normal sample pairs

Johannes Köster

Structural variants can play a key role in tumor development. We present a novel Bayesian latent variable model to call structural variants in sequenced tumor/normal sample pairs that incorporates various levels of uncertainty. It thereby significantly improves classification into somatic and germline events, while in addition allowing accurate allele frequency estimation and false discovery rate control.

For further information please contact: Johannes Köster ([email protected])


2nd Floor Key words: somatic variant calling, tumor genomes, sequencing, Bayesian statistics

Poster Nbr. CGPA P2



Reproducible data analysis with Snakemake

Johannes Köster

Reproducible and scalable data analyses are crucial to obtain reliable insights from today's high throughput technologies. With the popular workflow management system Snakemake we provide a powerful framework to formalize parallelize, and reproducibly execute data analyses on workstations, compute servers and clusters.

For further information please contact: Johannes Köster ([email protected])


2nd Floor Key words: data analysis, bioinformatics Poster Nbr.

CGPA P3



HLA-DM modulates the susceptibility of leukemia to CD4+ T cell alloreactivity in cellular therapy

Pietro Crivello, Esteban Arrieta-Bolaños, Maximilian Metzing, Michel Kester, Dominik Megger, Weiqiang Chen, Thuja Meurer, Kees van Bergen, Marieke Griffioen, Luca Vago, Simone Thomas, Wolfgang Herr, Dietrich W. Beelen, Peter A. Horn, Barbara Sitek, J.H. Frederik Falkenburg, Katharina Fleischhauer

Introduction:

CD4+ T cell alloreactivity against HLA-DP donor-recipient mismatches is an important mediator of the anti-leukemia effect in hematopoietic stem cell transplantation (SCT). Low immunogenicity of certain HLA-DP antigens is controlled by the intracellular chaperone HLA-DM, which mediates removal of class II-invariant-chain-associated-peptide (CLIP) and modulation of the presented immunopeptidome. Loss of HLA-DM, described as immune escape mechanism for different hematologic malignancies, might lead to alteration of the HLA-DP immunopeptidome resulting in higher susceptibility to CD4+ T cell alloreactivity after HLA-DP mismatched SCT.


Primary blasts from HLA-DP typed leukemia patients were tested for the expression of cell surface CLIP and intracellular HLA-DM. Recognition of mismatched HLA-DP on leukemia blasts by alloreactive T cells was quantitatively assessed by CD137 upregulation assays.

Results:

In the presence of similar HLA-DP cell surface levels, CLIP expression was inversely correlated with intracellular HLA-DM. Alloreactivity against CLIPhigh blasts was significantly higher compared to CLIPlow blasts (p = 0.019).

Conclusion:

Cell surface CLIP expression might be a surrogate marker for intracellular HLA-DM activity and susceptibility to immune mediated control of leukemia by CD4+ T cell alloreactivity after HLA-DP mismatched SCT. These findings might have clinical implications for the implementation of innovative treatment strategies in cellular therapy.

For further information please contact: Pietro Crivello ([email protected])

Experimental Cellular Therapy, University Hospital Essen

2nd Floor Key words: CLIP, leukemia, HLA-DP, stem cell transplantation, T cell alloreactivity

Poster Nbr. CIT P1



Epigenetic profiling distinguishes variant MCC cell lines from classical MCC

Jan Gravemeyer, Corinna Wülbeck, Ivelina Spassova, Anita Melio, Thilo Gambichler, Anja Lange, Cathrin Ritter, Jürgen C. Becker

Introduction:

The rarity of Merkel cell carcinoma (MCC) mandates the use of cell lines to study its biology. However, some MCC cell lines, aka variant MCC cell lines (vMCCs), are suspected to be derived from another cancer entity and could thus severely distort cell line based studies. Here, we test if vMCCs MCC13 and MCC26 are indeed distinct from classical MCCs (cMCCs).


DNA methylation was measured using the Illumina Infinium MethylationEPIC Kit and mRNA and microRNA (miR) expression using nanoString technology.

Results: DNA methylation based clustering demonstrated that vMCCs cluster distinct from cMCCs. A functional characterization of more than 700 differentially expressed genes showed an enrichment for epithelial-mesenchymal transition (EMT) related genes. The majority of those were up-regulated in vMCCs compared to cMCC. Moreover, the miR-clusters 183-96-182 and miR-200c-141 were differentially expressed in cMCCs and vMCCs. Notably, both miR-clusters regulate EMT and expression differences are caused by differential DNA methylation.

Conclusion:

Our results suggest that vMCC cell lines substantially differ from cMCC cell lines. Consequently, in vitro studies based on vMCC cell lines should be interpreted with caution.

For further information please contact: Jan Gravemeyer ([email protected])

Translational skin cancer research, German Cancer Consortium (DKTK), University Hospital Essen

2nd Floor Key words: MCC, microRNA, gene expression, methylation, EMT

Poster Nbr. CIT P2



Ovarian cancer immunotherapy by antibody-nanoparticle conjugates and natural killer cell activation

Martin Obholzer, Sonja Benders, Carla Even-Schäfer, Sebastian Kollenda*, Matthias Epple*, Nina Mallmann-Gottschalk, Sven Brandau

Introduction:

NK cells can harbor potent anti-tumor cytotoxicity. Multi-shell calcium phosphate nanoparticles (CaP-NPs) can be functionalized by incorporation of siRNA, DNA expression plasmids and antibody conjugation. In this project we aim to functionalize CaP-NPs in order to enhance binding to ovarian cancer cells and simultaneously enhance NK killing of tumor cells.


Ovarian cancer cells will be transfected by nanoparticles, which are functionalized by anti-MHC class I siRNA or other molecules, which enhance NK activation. Additionally, nanoparticles may initiate ADCC to ovarian cancer cells via Cetuximab coating. Modulation of tumor cells and NK cell activation will be assessed. In addition we will explore the effect of ovarian cancer-induced ascites on the tumor-NK interaction. Based on the in vitro results, selected candidate molecules will be tested in murine xenograft models of cancer immunotherapy.

Results:

Preliminary experiments showed that the anti-EGFR antibody Cetuximab enhances ADCC and leads to lysis of NK cell-resistant ovarian cancer cell lines. Furthermore, we observed a reduced MHCI-expression of Tyrosine-kinase-inhibitor-sensitized cancer cells. The effects of different nanoparticle formulations on NK cell biology are currently investigated.

Conclusion:

CaP-NP can be used to modulate the biology of tumor cells. In order to fully explore the potential of CaP-NP in cancer immunotherapy, direct effects on immune effector cells need to be further investigated.

For further information please contact: Martin Obholzer ([email protected])

Research Division, Dept. of Otorhinolaryngology, Prof. Dr. rer. nat. Sven Brandau, University Hospital Essen

2nd Floor Key words: Ovarian Cancer, Nanoparticle, ADCC, NK cells Poster Nbr.

CIT P3



SCIENCE

BRAF/MEK inhibitor treatment causes altered TCR repertoire usage of tumor-infiltrating lymphocytes in melanoma

Lukas Peiffer, Ivelina Spassova, Mohammadkarim Saeedghalati, Daniel Hoffmann, Dirk Schadendorf, Jürgen C. Becker

Introduction:

Oncogenic mutations in BRAF are common in melanoma. Consequently, BRAF/MEK inhibitors are frequently used for therapy of advanced disease. The impact of these inhibitors on adaptive immune responses, however, is still controversial. Indeed, both detrimental as well as boosting effects have been described.


The immune response to melanoma of 4 patients before and under BRAF/MEK inhibitor therapy was characterized by NGS-based T-cell clonotype mapping (TCR-Seq, Adaptive®) of tumor-infiltrating lymphocytes and by a multiplexed immunofluorescence (Opal®) for CD4, CD8, CD20, FoxP3, CD68 and MART-1 on archived FFPE tissue.

Results:

TCR-seq revealed an overall increase in TCR templates together with a reduction of TCR clonality and higher diversity in two of the patients. Applying the GLIPH algorithm, which clusters TCRs according to the local and global similarity of their CDR3 region, demonstrated that BRAF/MEK inhibition induced both an increase in the number as well as of the size of the clusters, which are likely to react with same antigen. The immune phenotyping of the infiltrate revealed an increased intratumoral infiltration of CD4 and CD8 T cells, whereas the magnitude and localization of B cell, regulatory T cells or macrophages was not altered.

Conclusion:

These results suggest BRAF/MEK inhibition in a subset of melanoma patients is associated with enhanced adaptive immune response with greater diversity of T cell responses, which, however, appears to be directed to a limited set of antigens. This notion is in line with recent reports demonstrating that MEK inhibition can reactivate T cells with an exhausted phenotype.

For further information please contact: Lukas Peiffer ([email protected])

Translational Skin Cancer Research, AG Becker University Hospital Essen

2nd Floor Key words: Melanoma, BRAF/MEK inhibition, adaptive immune response, TCR repertoire

Poster Nbr. CIT P4



Functional interplay in the tumor microenvironment: cross-talk between neutrophils, tumor cells and tumor-associated stromal cells.

Jagoda Szlachetko, Kirsten Bruderek, Stephan Lang, Sven Brandau

Introduction:

In patients with malignant disease, neutrophils are recruited to tumor tissue. These tumor-associated neutrophils (TAN) can be localized in mesenchymal, stromal regions of the tumor or in epithelial tumor nests. A high prevalence of neutrophils in the tumor tissue is often associated with poor prognosis in many types of cancer. Despite this pathobiological importance, it is unclear how neutrophils are recruited to different areas of tumor tissue and how intratumoral localization affects the biology of the TAN.


We established an in vitro system to analyze the cross-talk of neutrophils with tumor cells and tumor-associated fibroblastoid mesenchymal stromal cells (MSC).

Results:

Our data show a distinct cytokine profile of cancer cells and MSC. This cytokine profile is changed upon reciprocal interaction of cancer cells and MSC. Modulation is mostly mediated by tumor-derived microvesicles. Interestingly, exposure of neutrophils to supernatants of MSC, which were previously exposed to tumor cell-derived factors, led to significant changes in migration and biology of the neutrophils.

Conclusion:

Our data suggest a cross-talk of tumor cells and stromal cells with functional consequences for the biology of tumor-associated neutrophils.

For further information please contact: Jagoda Szlachetko ([email protected])

Department of Otorhinolaryngology, Research Division Prof. Sven Brandau, University Hospital Essen

2nd Floor Key words: Tumor microenvironment, neutrophils, mesenchymal stromal cells, extracellular vesicles

Poster Nbr. CIT P6



Domatinostat increases apoptosis, G2M cell cycle arrest and immunogenicity of Merkel cell carcinoma

Lina Song, Anne Catherine Bretz, Jan Gravemeyer, Ivelina Spassova, Shakhlo Muminova, Rene Bartz, Jürgen C. Becker.

Introduction: Merkel cell carcinoma (MCC) is a rare, highly aggressive skin cancer prevalent in elderly and immunocompromised patients. MCC is highly immunogenic as it is either associated with Merkel cell polyoma virus (MCPyV) integration or UV-associated mutations in non-viral cases. Indeed, immune checkpoint inhibitors (CPI) like PD-1/PD-L1 blocking antibodies exert a strong clinical activity; however, primary or secondary resistance often occurs. Domatinostat (4SC-202) is an orally available small molecule inhibitor targeting histone deacetylases (HDAC) class I currently in clinical evaluation to improve response to CPI (SENSITIZE, NCT03278665). In syngeneic tumor mouse models domatinostat treatment demonstrated immune-modulatory effects by increasing the intra-tumoral infiltration of cytotoxic CD8+ T cells (CTLs) and enhancing gene expression of a CPI response signature. Immune escape mechanisms described for MCC include low intra-tumoral levels of CTLs and reduced expression of antigen-presenting MHC class I molecules. Our previous data suggest that low MHC-I levels are reversible and involve epigenetic silencing of genes encoding the antigen-processing machinery (APM).

Results: Here, we present novel preclinical data about the efficacy and mode of action of domatinostat in MCC. Global gene expression by single cell RNA-seq revealed regulation of genes involved, among others, in apoptosis and antigen presentation. Importantly, domatinostat additionally inhibited proliferation of MCC cell lines by induction of a G2M cell-cycle arrest and apoptosis. Moreover, expression of MCPyV-encoded transforming early genes, particularly during the G1-phase, was inhibited by domatinostat. Thus, it exerts also a direct anti-tumoral effect. In viable cells, domatinostat increases their susceptibility to immune responses, as qPCR and immunoblot analysis confirmed the induction of APM and MHC-I expression by domatinostat. APM and MHC-I expression has been reported to be restored by an epigenetic drug combination (vorinostat plus mithramycin). In contrast, we now provide evidence that the single agent treatment with domatinostat alone is sufficient for increasing immunogenicity of MCC cells.:

Conclusion: In summary, domatinostat counteracts immune escape of MCC in many aspects suggesting a combination treatment of the HDACi domatinostat with CPI as a promising therapeutic strategy. Prospective clinical trials are needed to confirm this hypothesis.

For further information please contact: Lina Song ([email protected])

Translational Skin Cancer Research, AG Becker, University Hospital Essen

2nd Floor Key words: MCC/skin cancers ; Antigen presentation ; Histone deacetylase inhibitor ; Cell cycle arrest

Poster Nbr. CIT P5



IFN-dependent bystander killing of melanoma cells by CD8+ T cells and mechanisms of resistance

Beatrice Thier1,3, Fang Zhao1,3, Sonia Leonardelli1,3, Marion Schwamborn1,3, Dirk Schadendorf1,3, Mirko Trilling2, Annette Paschen1,3

Introduction:

Cytotoxic CD8+ T cells become activated upon recognition of cognate HLA class I surface antigens on melanoma cells. This leads to cytolytic granule release inducing target cell death. Moreover,

activated T cells secrete the proinflammatory cytokine IFN, that has recently been demonstrated

to play a fundamental role in tumor elimination. IFNinduced JAK-STAT1 signaling pathway activation in tumor cells can inhibit proliferation or even induce cell death. We assume that

IFNacts on bystander tumor cells and extends tumor control by T cells, even in the absense of direct T cell/tumor crosstalk.


We took advantage of different melanoma models consiting of tumor cell lines and autologous

CD8+ T cells. IFN production by activated T cells was measured by intracellular cytokine staining. Viability of melanoma cells incubated with T cell-conditioned medium was determined in a MTT assay. Apoptotic cells were identified by AnnexinV-PI staining. Signaling pathway activation and cell surface receptors were analyzed by Western Blot and flow cytometry, respectively.

Results:

Incubation with T cell-conditioned medium induced melanoma cell apoptosis. Cell death could

partly be blocked in the presence of antibodies abrogating IFN-receptor binding. Six out of seven

melanoma cell lines responded to IFN treatment with apoptosis, while Ma Mel-51 cells continously proliferated. Interestingly, the latter showed intact JAK-STAT1 pathway activation, suggesting escape from cytokine-induced cell death downstream of the signaling cascade.

Conclusion:

Taken together, T cell-derived IFNγ induces bystander killing of melanoma cells. But tumor cells can escape cytokine-induced cell death by so far unknown mechanisms which are under investigation.

For further information please contact: Beatrice Thier ([email protected])

Klinik für Dermatologie; AG Molekulare Tumorimmunologie, AG Paschen University Hospital Essen

2nd Floor Key words: IFN, CD8+ T cells, melanoma, bystander killing, resistance

Poster Nbr. CIT P7



SCIENCE

Combined HLA class I and HLA class II genotype alterations in melanoma from patients with primary and acquired resistance to

immune checkpoint blockade

Fang Zhao, Marion Schwamborn, Beatrice Their, Pietro Crivello, Andreas Heinold, Thuja Meurer, Volker Lennerz, Antje Sucker, Klaus Griewank, Peter A. Horn, Selma Ugurel, Thomas Wölfel, Katharina Fleischhauer, Dirk Schadendorf, Annette Paschen

Introduction:

Effective tumor immunotherapy relies on CD8 T cell-mediated tumor killing upon recognition of cognate tumor antigen-HLA class I (HLA-I) complexes. Hence, HLA-I gene defects can protect tumor from T cell surveillance and contribute to immunotherapy resistance. Moreover, increasing evidences address the importance of CD4 T cells in HLA-II-dependent tumor elimination. But, knowledge on HLA-II alteration and its role in immunotherapy are lacking. Here, we studied consecutive metastases from different melanoma patients for HLA-I and HLA-II gene defects and addressed their functional relevance in anti-tumor T cell responses.


HLA gene alterations in 34 consecutive metastases from 12 patients were analyzed using targeted sequencing. Tumor-reactive T cells were expanded by weekly stimulating peripheral blood T cells or tumor-infiltrating lymphocytes with irradiated autologous tumor cells. T cell activation was

Results:

9 metastases from 3 out of 12 patients (25%) showed HLA haplotype loss covering both HLA-I and HLA-II genes. Re-expression of lost HLA genes sensitized corresponding tumor cells to both autologous allele-specific CD8 and CD4 T cells. Combined HLA-I/HLA-II gene alterations were detected in metastases from patients with primary and acquired resistance to immune checkpoint blockade.

Conclusion:

Melanoma can evade T cell surveillance via combined HLA-I/HLA-II haplotype loss, suggesting that productive anti-tumor T cell responses might select for tumor cells lacking ‘key’ HLA genes. Characterizing HLA gene loss may have implications for predicting response to immunotherapy and our understanding of resistance mechanisms.

For further information please contact: Fang Zhao ([email protected])

Department of Dermatology, Molecular Tumor-Immunology, University Hospital Essen

2nd Floor Key words: melanoma, HLA haplotype loss, resistance to immune checkpoint blockade, tumor escape, T cells

Poster Nbr. CIT P8


Floor Plan

Ground Floor


PLAN 1st and 2nd FLOOR


INDEX PRESENTERS Last Name, First Name Email Talk / Poster

Ahci-Hanci, Müberra [email protected] T3

Ahlert, Heinz [email protected] MTT P1

Ahmadov, Ulvi [email protected] MDEB P1

Aretz, Philippe [email protected] EOM P1

Arjmand Abbassi, Y. [email protected] MDEB P2

Asperger, H. and

Cieslik, J.

[email protected]; [email protected]; [email protected]

CCP P1

Barbeau, Lydie [email protected]; T18

Bartl, Jasmin [email protected] T11

Bäumer, Christian [email protected] T14

Bazarna, Anna [email protected] T18

Blümel, Lena [email protected] MDEB P3

Borchert, Sabrina [email protected] MDEB P4

MTT P6

Bordbari, Shareh [email protected] EOM P2

Brandau, Sven [email protected] T9

Chauvistré, Heike [email protected] T8

Crivello, Pietro [email protected] CIT P1

Cull, Alyssa [email protected] EOM P3

Dierichs, Laura [email protected] T4

Dorsch, Madeleine [email protected] T5

Fendler, Wolfgang [email protected] T13

Forster, Jan [email protected] CGPA P1

Franken, André [email protected] T10

Gravemeyer, Jan [email protected] CIT P2

Hassiepen, Christina [email protected] EOM P4

Hegedus, Luca [email protected] MTT P3

Ho, Cassandra [email protected] MDEB P5

Jazmati, Danny [email protected] ROI P7

Kahmann, Karlotta [email protected] MTT P4

Karakaya, Sinan [email protected] MTT P5

Köster, Johannes [email protected] CGPA P2

CGPA P3

Lang, Franziska [email protected] MTT P2

mailto:[email protected]


Last Name, First Name Email Talk / Poster

Lange, Erik [email protected] EOM P5

Langer, Samantha [email protected] T17

Langini, Maike [email protected] MDEB P6

Liffers, Sven-T. [email protected] MTT P7

Lohmann, Dietmar [email protected] MDEB P7

Lollies, Anna [email protected] EOM P6

Lu, I-Na [email protected] T19

Ludescher, Marina [email protected] EOM P7

Mairinger, Elena [email protected] EOM P8

MTT P9

Mairinger, Fabian Dominik [email protected] MTT P8

Marquardt, Viktoria [email protected] MDEB P8

Matschke, Johann [email protected] T15

Mergener, Svenja [email protected] MTT P10

Nagaraja, Sindhu [email protected] ROI P2

Naser, Eyad [email protected] MTT P11

Nothdurft, Silke [email protected] T7

Obholzer, Martin [email protected] CIT P3

Patil, Ashwini [email protected] EOM P9

Peiffer, Lukas [email protected] CIT P4

Peters, Sarah [email protected];[email protected] ROI P3

Picard, Daniel [email protected] MDEB P14

Placke, Jan-Malte [email protected] EOM P10

Qin, Nan [email protected] MDEB P10

Rösch, Alexander [email protected] T12

Rudner, Justine [email protected] ROI P4

Schmeller, Jan [email protected] MDEB P11

Seifert, Marc [email protected] T16

Shannan, Batool [email protected] T6

Siakaeva, Elena [email protected] EOM P11

Song, Lina [email protected] CIT P5

Spassova, Ivelina [email protected] T2

Stamm, Nadia [email protected] EOM P12

Staniszewska, Magdalena [email protected] ROI P5


Last Name, First Name Email Talk / Poster

Szlachetko, Jagoda [email protected] CIT P6

Szymonowicz, Klaudia [email protected] ROI P6

Taban, Kübra [email protected] MDEB P12

Temming, Petra [email protected] MDEB P13

Thier, Beatrice [email protected] CIT P7

Thumser-Henner, Clothilde [email protected] ROI P1

Tsiampali, Nerantzoula [email protected] EOM P13

Ueffing, Kristina [email protected] MTT P12

Ullrich, Vivien [email protected] EOM P14

Varaljai, Renata [email protected] MDEB P9

Vega Rubin de Celis, Silvia [email protected] EOM P15

Verbeek, Nico [email protected] ROI P8

Weiß, Annika [email protected] EOM P16

Wessolly, Michael [email protected] EOM P17

Wiesweg, Marcel [email protected] T1

MDEB P15

Wossidlo, Natalie [email protected] EOM P18

Yusuf, Suad [email protected] EOM P19

Zegar, Tim [email protected] MTT P13

Zhao, Fang [email protected] CIT P8

Documents

E T O S FEBRUARY TH 2019 - DKTK · Targeting cancer stem cells and immune escape ... Functional analysis of CD30 in Hodgkin and anaplastic large cell lymphoma cell lines by CRISPR/Cas9-mediated