127HPV16 E6/E7 induced EMT is Twist dependent and can promotecarcinogenesis and metastasis of cervical cancerT. Wang, Y. Li. Cancer Biology Research Center, Tongji Hospital, TongjiMedical College, Wuhan, China.

Objective: Human papillomaviruses (HPVs) are recognized as theetiological agent of cervical cancer that local invasion is the majorway to metastasis. P53 and retinoblastoma proteins are well-characterized targets of the HPV16 E6/E7 oncoproteins. However,recent studies figured out that the alterations of additional pathwaysare equally important for transformation. Meanwhile, cancer-asso-ciated epithelial to mesenchymal transition (EMT) has been focusedand considered as a critical phenomenon in invasion and metastasissuch as breast cancer and prostate cancer these days, but little itemsinvolve in cervical cancer. This study aims to investigate that whetherEMT participates the tumorigenesis and metastasis of cervical canceror not, additionally, whether EMT associates with HPV oncoproteinsor known EMT inducers independent or not.Methods: 1. We used mRNAmicroarray analysis to determine the roleof HPV16 E6/E7 in modulating the expression of EMT-related genesbased on the information from cervical epithelial cell with stableexpression of HPV16 E6/E7 compared to normal cervical epithelialcells. 2. We examined the expression of E-cadherin mRNA and proteinfollowing HPV16 E6/E7 activation and found that HPV16 E6/E7 doesnot directly suppress E-cadherin transcription during EMT. 3. We usedwestern blot and realtime-PCR to learn about the role of Twist inHPV16 E6/E7 induced EMT, and demonstrated that the induction ofthe transcription factor Twist is required for HPV16 E6/E7-inducedEMT. 4. We used migration and invasion assays to study the role ofTwist to the ability HPV16 E6/E7 to promote invasion and metastasisin vitro and significance of Twist on HPV16 E6/E7 inducedtumorigenesis and metastasis in vivo. 5. We confirmed the relation-ship among HPV16 E6/E7, Twist and E-cadherin in tissue microarraywith normal cervical tissues, CIN and cervical cancer tissues.Results: 1. HPV16 E6/E7 modulate expression of genes involved inEMT and differentiation-associated processes in human cervicalepithelial cells. 2. HPV16 E6/E7 indirectly suppresses E-cadherintranscription to promote EMT. 3. Induction of the transcription factorTwist is required for HPV16 E6/E7-induced EMT. 4. Induction of Twistis required for the ability of HPV16 E6/E7 to promote tumorigenesis,invasion and metastasis. 5. HPV16 E6/E7 and Twist are frequentlycoexpressed in human cervical cancer.Conclusions: HPV16 E6/E7 induced EMT is Twist dependent and canpromote carcinogenesis and metastasis of cervical cancer.

doi:10.1016/j.ygyno.2011.12.128

128Elastic light scattering spectroscopy versus standard colposcopy inpatients with abnormal cervical cytologyH. Smith1, D. Maheswari Narasimhulu1, H. Greene2, S. Gottimukkala1,O. Marina3, M. Frimer1, T. Hebert1, M. Einstein1, J. Mourant3. 1AlbertEinstein College of Medicine/Montefiore Medical Center, Bronx, NY,2University of New Mexico, Albuquerque, NM, 3Bioscience Division, LosAlamos National Laboratories, Los Alamos, NM.

Objective: Elastic light scattering spectroscopy (ELSS) is capable ofmeasuring light scattering in cervical tissues and is being evaluated inthe setting of abnormal cervical cytology to determine if it cansupplement or replace colposcopy in identifying clinically relevantcervical intraepithelial neoplasia (CIN2/3). The objective of this studyis to compare ELSS with clinical impression using colposcopic-directed biopsy histology as the gold standard.

Methods: Colposcopic methods were defined by protocol, withoversampling to improve performance. Two complete ELSSmeasurements (2 polarized/2 non-polarized) were obtained fromeach site. High risk (HR) was defined as cervical intraepithelialneoplasia (CIN2/3, AIS, invasive cancer) and low-risk (LR), asnormal, inflammatory, metaplasia, or CIN1. True positive (TP) wasdefined as concordance with histology, false positive as clinical/ELSS HR but histology LR, true negative (TN) as clinical/ELSS LRand histology LR, and false negative (FN) as clinical/ELSS LR, buthistology HR. Sensitivity (S), specificity (SS), positive (PPV) andnegative predictive value (NPV) by clinician and ELSS weredetermined.Results: Seven clinicians (5 GYN, 2 GYNONC) from 2 institutionsparticipated; 252 biopsy sites involving 172 patients were com-pared. In the site-specific analysis, for colposcopy and ELSS, thenumber of TP, TN, FP, and FN were 47, 132, 55, and 18, and 52, 99, 88,and 13, respectively. Colposcopy had a S/SS/PPV/NPV of 72.3%,70.6%, 46.1, and 88.0%. ELSS had a S/SS/PPV/NPV of 80.0%, 52.9%,37.1%, and 88.4%.Secificity was significantly higher for colposcopy(70.6%, 95% CI 63.4%, 76.9%). For patient-specific data, colposcopyhad S/SS/PPV/NPV of 72%, 73.8%, 52.9% and 86.5% compared with88.0%, 44.3%, 39.3% and 90% for ELSS. Again, specificity wassignificantly higher for colposcopy. Compared by specialty (GY-NONC vs. GYN), no significant differences were found. The ELSSprocedure increased the time required for colposcopy by 45seconds (1 site) to 3.5 minutes (5 sites).Conclusions: Colposcopy and ELSS have similar sensitivity, PPV andNPV for site- or patient-specific detection of high grade (CIN2/3)cervical lesions, while colposcopy has a higher specificity. Anunderstanding of the causes of FN's and FP's is needed to improveboth techniques. Further investigation of ELSS in the colposcopysetting with additional testing such as HPV typing, as well asdetermining the correlation ELSS and colposcopic results is war-ranted to develop ELSS to its full potential.

doi:10.1016/j.ygyno.2011.12.129

129Poly (ADP-Ribose) polymerase inhibition attenuatesradiation-induced non-homologous end-joining repair andaugments cervical cancer response to radiationE. Yang, S. Nowsheen, T. Cooper, C. Landen, J. Bonner. UABComprehensive Cancer Center, Birmingham, AL.

Objective: Inhibition of poly(ADP-Ribose) (PAR) polymerase(PARP), a key single-strand DNA repair enzyme, has shown activityin combination with radiotherapy in a number of cancer types. Inthis study, we investigated whether the PARP inhibitor ABT-888could improve efficacy of radiotherapy in human cervical cancercells.Methods: CaSki and HeLa human cervical cancer cellular suscept-ibility to the PARP inhibitor (PARPi) ABT-888 and/or radiation (IR)was assessed using colony formation assays and assessments of DNAdamage. Since the DNA double strand break (DSB) is the most lethallesion in a cell, DSBs were evaluated using immunostaining for γ-H2AX foci. Non-homologous end-joining (NHEJ) and homologousrecombination (HR) mediated repair were measured using phospho-DNA-Pk and Rad51 foci, respectively. Activation of apoptosis wasassessed by detection of cleaved caspase 3 and 9 via immunoblotanalysis. PAR levels, which are indicative of PARP activity, were alsoassessed using immunoblotting.Results: Human cervical cancer cells exhibited enhanced cytotoxi-city with IR and ABT-888 compared to either agent alone (2.5-10

Abstracts / Gynecologic Oncology 125 (2012) S3–S167S54