PND-1186 FAK inhibitor selectively promotes tumor cell apoptosis in three-dimensional environments

Abstract

Tumor cells can grow in an anchorage-independent manner. This is mediated in part through survival signals that bypass normal growth restraints controlled by integrin cell surface receptors. Focal adhesion kinase (FAK) is a cytoplasmic protein-tyrosine kinase that associates with integrins and modulates various cellular processes including growth, survival, and migration. As increased FAK expression and tyrosine phosphorylation are associated with tumor progression, inhibitors of FAK are being tested for anti-tumor effects. Here, we analyze PND-1186, a substituted pyridine reversible inhibitor of FAK activity with a 50% inhibitory concentration (IC50) of 1.5 nM in vitro. PND-1186 has an IC50 of ~100 nM in breast carcinoma cells as determined by anti-phospho-specific immunoblotting to FAK Tyr-397. PND-1186 did not alter c-Src or p130Cas tyrosine phosphorylation in adherent cells, yet functioned to restrain cell movement. Whereas 1.0 µM PND-1186 (>5-fold above IC50) had limited effects on cell proliferation, under non-adherent conditions or when grown as spheroids or colonies in soft agar, 0.1 µM PND-1186 blocked FAK and p130Cas tyrosine phosphorylation, promoted caspase-3 activation, and triggered cell apoptosis. PND-1186 inhibited 4T1 breast carcinoma subcutaneous tumor growth correlated with elevated tumor cell apoptosis and caspase 3 activation. Addition of PND-1186 to the drinking water of mice was well tolerated and inhibited ascites-associated ovarian carcinoma tumor growth associated with the inhibition of FAK tyrosine phosphorylation. Our results with low-level PND-1186 treatment support the conclusion that FAK activity selectively promotes tumor cell survival in three-dimensional environments.

Pyk2 promotes tumor progression in multiple myeloma

“…on May 9, 2018. by guest www.bloodjournal.org From clinical-stage FAK/PYK2 inhibitor, such as VS-4718. VS-4718 (formerly known as PND-1186) has been previously described as a FAK inhibitor, [24][25][26] and we are now reporting its inhibitory activity against Pyk2, which led to inhibition of MM cell growth both in vitro and in vivo. In addition, because Pyk2 inhibitors may be potentially applicable as a bone anabolic approach for osteoporosis due to enhancement of bone formation, 16 we could anticipate that Pyk2 inhibitor treatment may also help in the treatment of myeloma bone disease.…”

“…[24][25][26] VS-4718 was provided by Verastem (Cambridge, MA). For in vitro assays, VS-4718 was dissolved in dimethylsulfoxide and prepared as a 10 mM stock and diluted in culture medium at indicated concentrations.…”

N-WASP-directed actin polymerization activates p130Cas phosphorylation and lamellipodium spreading

“…4A) and further inhibition of this site with a pharmacological inhibitor of FAK did not affect CasSD phosphorylation. Similarly, another study of pharmacological inhibition of FAK also reveals that CasSD phosphorylation is independent of phosphorylation of FAK residue Y397 (Tanjoni et al, 2010). Compared with the previous approach, which relied heavily on overexpression systems, our approach allowed us to acutely manipulate the kinase activity without disrupting the endogenous protein level.…”

“…3I-K). An independent study using another FAK-specific inhibitor also showed that kinase activity of FAK was not required for SFK activity or adhesion-dependent CasSD phosphorylation (Tanjoni et al, 2010). The fact that these results do not support the existing model could reflect the differences between biochemical assays which use overexpressed or endogenous protein levels.…”

A non-canonical role for Rgnef (p190RhoGEF) in promoting integrin-stimulated focal adhesion kinase activation

“…The molecular mechanisms controlling FAK activation are of potential clinical relevance owing to the fact that FAK controls various aspects of tumor progression (Zhao and Guan, 2009). Small molecules that act as ATP-competitive inhibitors of FAK activity are in various stages of development and are being tested in human clinical trials (Halder et al, 2007;Roberts et al, 2008;Tanjoni et al, 2010;Walsh et al, 2010;Ward et al, 2013). As Rgnef-FAK signaling promotes colon cancer tumor spread (Yu et al, 2011), and we find that Rgnef knockdown reduces FN-stimulated FAK activation in ovarian carcinoma cells, we hypothesize that Rgnef might be an important contributing mechanism promoting FAK activation in tumor cells.…”