1

FAK INHIBITORS: A STRATEGY TO COMBAT CANCER

BY MADHURI H.JAIN F.Y.M-PHARM(PHARM.CHEM.)

UNDER THE GUIDANCE OF Dr. RAKESH R. SOMANI

(HOD:PHARMACEUTICAL CHEMISTRY)

Thursday 13 April 2023

Thursd

ay 1

3 A

pril 2

02

3

2

CONTENTS

Cancer Rationale for FAK inhibition Introduction to FAK Basic activation pathways of FAK FAK inhibitors Clinical Challenges Conclusion

Thursd

ay 1

3 A

pril 2

02

3

3

CANCER Cancer is characterized by unregulated and

uncontrolled growth of cells. Normal cells undergo a programmed cell death (apoptosis).

However, cancer cells do not undergo apoptosis, and continue to grow and divide forming malignant (cancerous) tumors.

If the spread of these tumors to the other organs of the body is not controlled, it can result in death.

To prevent the unregulated and uncontrolled growth of cells, many anti-cancer agents have been developed.

Thursd

ay 1

3 A

pril 2

02

3

4

TYPES OF AGENTS MECHANISM OF ACTION EXAMPLES

ALKYLATING AGENTS AND ANTIBIOTICS

INHIBIT DNA SYNTHESIS AND CELL DIVISION

CYCLOPHOSPHAMIDE, DACTINOMYCIN

ANTIMETABOLITES

FOLATE ANTAGONIST INHIBITS DHFR METHOTREXATEPURINE ANTAGONIST INHIBITION OF PURINE

RING BIOSYNTHESISMERCAPTOPURINE

PYRIMIDINE ANTAGONIST INHIBITION OF PYRIMIDINE RING BIOSYNTHESIS

FLUOROURACIL

NATURAL COMPOUNDS

VINCA ALKALOIDS INHIBITION OF TUBULIN VINCRISTINE

HORMONAL ANTAGONIST

AROMATASE INHIBITORS INHIBITION OF AROMATASE

ANASTRAZOLE

ANTI-ANDROGEN AGENT INHIBITION OF ANDROGEN RECEPTOR

FLUTAMIDE

LIST OF ANTICANCER AGENTS

Thursd

ay 1

3 A

pril 2

02

3

5

DISADVANTAGES OF CONVENTIONAL THERAPIES

However, the conventional therapies are associated with problems such as:Severe toxicityDevelopment of resistance Not well tolerated in patientsNot cell specificRelapse of cancer

Thursd

ay 1

3 A

pril 2

02

3

6

RATIONALE FOR FAK INHIBITION: FAK is a key regulator of cell survival, proliferation,

migration and invasion: processes that are all involved in the development and progression of cancer.

FAK is also linked to oncogenes at both biochemical and functional level.

Overexpression of FAK in wide variety of cancer is quite significant.

Important role of FAK in tumorigenesis, angiogenesis, metastasis and survival signalling FAK should be regarded as a potential target in the development of anti-cancer drugs.

Thursd

ay 1

3 A

pril 2

02

3

7

INTRODUCTION TO FOCAL ADHESION KINASE (FAK)

Focal adhesion kinase (FAK) is a 125- kDa non receptor, cytoplasmic tyrosine kinase that modulates cell adhesion, migration, proliferation and survival of cell.

It belongs to protein tyrosine kinase family. In addition to being a key player in regulating normal

cellular activities such as adhesion, migration and survival, FAK is also implicated in cancer cell invasion, metastasis and survival.

FAK is linked to the protection of cells from anoikis (suspension induced cell death).

Thursd

ay 1

3 A

pril 2

02

3

8

FAK STRUCTURE: It is encoded by a gene located on chromosome 8 in human

and houses three domains, the amino-N-terminal domain, the central catalytic domain and the carboxyl-C-terminal domain.

SCHEMATIC DIAGRAM OF FAK DOMAIN STRUCTURE WITH PHOSPHORYLATION SITES

FIGURE NO1 

Thursd

ay 1

3 A

pril 2

02

3

9

FUNCTIONS OF FAK:

ROLE OF FAK

ANGIOGENESIS

CELL ADHESION AND MIGRATION

CELL INVASION

CELL PROLIFERATION AND SURVIVAL

Thursd

ay 1

3 A

pril 2

02

3

10

CONTINUED…

FAK is activated through phosphorylation of its tyrosine sites like Tyr-397,407,576,577,861,925.

It is achieved through various pathways like:Src –FAK pathwayVEGFR-FAK pathwayPDGFR-FAK pathway

Thursd

ay 1

3 A

pril 2

02

3

11

BASIC ACTIVATION PATHWAY OF FAK:

Thursd

ay 1

3 A

pril 2

02

3

12

SRC-FAK PATHWAY:

FAK has a autophosphorylation site which is Tyr397. It act as a binding site for SH2 domain of Src to the

FAK. This FAK-Src complex promotes phosphorylation of

other tyrosine sites like Tyr-407,576,577,861and 925 leading to increased activity of FAK.

Thus promoting cell growth, cell adhesion and its survival.

Thursd

ay 1

3 A

pril 2

02

3

13

SRC-FAK PATHWAY:

Thursd

ay 1

3 A

pril 2

02

3

14

VEGFR-FAK PATHWAY

VEGF RELEASED FROM CELLS EXPOSED TO

HYPOXIA

VEGF BINDS TO VEGFR

CAUSES DIMERIZATION OF

RECEPTOR

LEADS TO PHOSPHORYLATION

OF FAK ENZYME

FAK ACTIVATION THROUGH VEGFR

LEADS TO ANGIOGENESIS

Thursd

ay 1

3 A

pril 2

02

3

15

VEGFR-FAK PATHWAY:

VEGF (VASCULAR ENDOTHELIAL GROWTH FACTOR) is a proangiogenic factor.

VEGF is released from cells which are exposed to hypoxia and partly because of increased transcription.

Binding of VEGF takes place to vascular endothelial growth factor receptor(VEGFR).

This leads to dimerization of the receptor. This cause phosphorylation of FAK. FAK activation through VEGF leads to angiogenesis, thus

providing continuous blood supply to cancerous cell.

Thursd

ay 1

3 A

pril 2

02

3

16

PDGFR-FAK PATHWAYPDGF RELEASED FROM MALIGNANT AND INFLAMMED CELLS

PDGF BINDS TO PDGFR

DIMERIZATION OF RECEPTOR TAKES PLACE

PHOSPHORYLATION OF SER-910 SITE OF FAK

ACTIVATION OF ENDOTHELIAL CELLS TO SECREATE MATRIX METTALOPROTEASES

THUS CAUSING MIGRATION AND PROLIFERATION

Thursd

ay 1

3 A

pril 2

02

3

17

PDGFR-FAK PAYTHWAY PDGF(PLATELET DERIVED GROWTH FACTOR) It is also a type of proangiogenic actor. It is released into the microenvironment by malignant, inflammatory and other

stromatal cells in response to various stimuli. PDGF binds to PDGF RECEPTOR which causes dimerization of receptor. This causes phosphorylation of Ser-910 site of FAK. This leads to activation of endothelial cells, stromatal cells and circulating endothelial

progenitor cells(CEPs) secrete several enzymes including matrix metalloproteases (MMPs) that break down the extra cellular matrix and allows endothelial cells to invade surrounding tissue thus causing proliferation and migration of cells.

\\\\\\\\\\\\

Thursd

ay 1

3 A

pril 2

02

3

18

FAK INHIBITORS:

FAK inhibitors can be divided into two main groups: The first group includes inhibitors targeting enzymatic

or kinase-dependent functions of FAK, such as inhibitors targeting the ATP-binding site domain and allosteric inhibitors that target other sites of FAK yet still block kinase activity, and

The second group includes inhibitors that target the FAK pathway.

Thursd

ay 1

3 A

pril 2

02

3

19

MECHANISM OF ACTION:(DRUGS TARGETING ATP BINDING SITE

For drugs like TAE-226 , PF-573,228 , PF-562,271 PND-1186 , COMPOUND 14

Thursd

ay 1

3 A

pril 2

02

3

20

TAE-226: Targets ATP binding site Y-397 on

FAK enzyme

PF-573,228 : blocked catalytic activity of recombinant FAK

Thursd

ay 1

3 A

pril 2

02

3

21

PF-562,271:Inhibits the phosphorylation of Tyr-397

PND-1186Inhibits FAK kinase activity , targets FAK binding site

Thursd

ay 1

3 A

pril 2

02

3

22

Thursd

ay 1

3 A

pril 2

02

3

23

NOVEL ALLOSTERIC FAK INHIBITORS:

Takeda developed non-ATP-competitive FAK allosteric inhibitors that efficiently decreased FAK functions. The Takeda identified tricyclic sulfonamides (compounds 1 and 2) that targeted a novel allosteric site in the C-lobe of the kinase domain, caused conformational changes of the kinase domain and induced disruption of ATP pocket formation and inhibition of FAK kinase activity

Thursd

ay 1

3 A

pril 2

02

3

24

MECHANISM OF ACTION :(DRUGS TARGETTING ALLOSTERIC SITE)

For drugs like Compound 1&2.

Thursd

ay 1

3 A

pril 2

02

3

25

INHIBITS BY BINDING TO ALLOSTERIC SITE OF THE FAK

INHIBITS BY BINDING TO ALLOSTERIC SITE OF THE FAK

Thursd

ay 1

3 A

pril 2

02

3

26

DRUGS TARGETING FAK PATHWAY:

Since FAK has so many binding partners such as Src, VEGFR,PDGF disruption of these complexes is an additional therapeutic approach to disrupt signals that FAK integrates and effectively block FAK regulated functions, another approach is to disrupt FAK interaction with these proteins.

The first approach to target the of FAK was performed by disrupting FAK and VEGFR with C4

Thursd

ay 1

3 A

pril 2

02

3

27

C4

Targets FAK-VEGFR pathway interaction.

Thursd

ay 1

3 A

pril 2

02

3

28

MISCELLANEOUS INHIBITORSA) Antisense oligonucleotides : They are single stranded DNA or RNA that are

complementary to a chosen sequence. They are directed towards the 5’ mRNA sequence of

FAK. When combined with 5-fluorouracil leads to

decreased FAK expression. Used in melanoma

Thursd

ay 1

3 A

pril 2

02

3

29

Antisense oligonucleotides:

Thursd

ay 1

3 A

pril 2

02

3

30

B) Thioridazine : It is an antipsychotic and anti anxiety drug. But has shown antiangiogenesis effect by inhibiting

phosphorylation of FAK, inhibiting VEGFR-FAK pathway.

Thursd

ay 1

3 A

pril 2

02

3

31

C) Mitoxantrone : It is type 2 topoisomerase inhibitor It has shown FAK inhibition by targeting ATP binding site. It acts on Src as well.

Thursd

ay 1

3 A

pril 2

02

3

32

CLINICAL CHALLENGES

Sensitivity of tumor cells to FAK Inhibitors Specificity of FAK inhibitors Discovery of biomarkers Single use or combination Chemoresistance

Thursd

ay 1

3 A

pril 2

02

3

33

CONCLUSIONo FAK research has answered many questions about

FAK-binding partners, the structure of its major domains and mechanisms of survival signalling. However, there are many questions that still remain unanswered about FAK to be answered in the future.

o Given the central role of FAK in cancer functions further refinements and understanding of its signalling pathways will lead to novel cancer therapy approaches.

Thursd

ay 1

3 A

pril 2

02

3

34

ACKNOWLEDGEMENT:

Dr. Rakesh R. SomaniDr .Supriya ShidhayeTeaching and non-teaching staffMy seniorsFamily and friends

Thursd

ay 1

3 A

pril 2

02

3

35

THANK YOU

Thursd

ay 1

3 A

pril 2

02

3

36

REFERENCES G.W. McLean, N.O. Carragher, E. Avizienyte, J. Evans, V.G. Brunton, M.C.

Frame,The role of focal-adhesion kinase in cancer - a new therapeutic opportunity , Nature Review Cancer 5 (2005) 505-515.

J.K. Slack-Davis, K.H. Martin, R.W. Tilghman, M.Iwanicki, E.J. Ung, C. Autry,M.J. Luzzio, B. Cooper, J.C. Kath, W.G. Roberts, J.T. Parsons, Cellular characterization of a novel focal adhesion kinase inhibitor, J. Biol. Chem. 282 (2007) 14845-14852.

Carragher, N. O. & Frame, M. C. Focal adhesion and actin dynamics: a place where kinases and proteases meet to promote invasion. Trends Cell Biol.(2004) 14,241-249.

Arora A, Scholar EM. Role of tyrosine kinase inhibitors in cancer therapy. J Pharmacol Exp Ther.(2005);315(3):971–9.

W.G. Cance, J.E. Harris, M.V. Iacocca, E. Roche, X. Yang, J. Chang, S. Simkins,L. Xu, Immunohistochemical analyses of focal adhesion kinase expression in benign and malignant human breast and colon tissues: correlation with preinvasive and invasive phenotypes, Clin. Cancer Res. 6 (2000) 2417-2423.

Thursd

ay 1

3 A

pril 2

02

3

37

REFERENCES: D. Lietha, M.J. Eck, Crystal structures of the FAK kinase in complex with

TAE226 and related bis-anilino pyrimidine inhibitors reveal a helical DFG conformation, PLoS One 3 (2008) 3800.

A. Schultze, W. Fiedler, Clinical importance and potential use of small molecule inhibitors of focal adhesion kinase, Anti-Cancer Agents in Medicinal Chemistry 11 (2011) 593-599.

S.T. Arold, M.K. Hoellerer, M.E. Noble, The structural basis of localization and signaling by the focal adhesion targeting domain, Structure 10 (2002) 319-327.

Choi, H.-S.; Wang, Z.; Richmond, W.; He, X.; Yang,K.;Jiang, T.; Sim, T.; Karanewsky, D.; Gu, X.-J.; Zhou, V.;Liu, Y.; Ohmori, O.; Caldwell, J.; Gray, N.; He, Y. Bioorg.Med. Chem. Lett. 2006.

Golubovskaya VM, Virnig C and Cance WG: TAE226-inducedapoptosis in breast cancer cells with overexpressed Src or EGFR. Mol Carcinog 47: 222-234,2008