BMS-777607, a Small-Molecule Met Kinase Inhibitor, Suppresses Hepatocyte Growth Factor–Stimulated Prostate Cancer Metastatic Phenotype In vitro

Abstract

Most prostate cancer-related deaths are due to advanced disease with patients with metastatic prostate cancer having a 5-year survival rate of only 34%. Overexpression of c-Met receptor tyrosine kinase has been highly associated with prostate cancer progression and metastasis. In the present studies, the effect of BMS-777607, a selective and potent small-molecule Met kinase inhibitor that has been advanced to clinical evaluation, on hepatocyte growth factor (HGF)-mediated cell functions and signaling pathways was evaluated in c-Met-expressing PC-3 and DU145 prostate cancer cells. BMS-777607 treatment had little effect on tumor cell growth but inhibited cell scattering activated by exogenous HGF, with almost complete inhibition at 0.5 micromol/L in PC-3 and DU145 cells. This agent also suppressed HGF-stimulated cell migration and invasion in a dose-dependent fashion (IC(50) < 0.1 micromol/L) in both cell lines. Mechanistically, nanomolar doses of BMS-777607 potently blocked HGF-stimulated c-Met autophosphorylation and downstream activation of Akt and extracellular signal-regulated kinase. In addition, both wortmannin and U0126, but not dasatinib, attenuated cell scattering and migration induced by HGF, suggesting the involvement of the phosphoinositide 3-kinase and mitogen-activated protein kinase pathways, but not of Src or focal adhesion kinase, in HGF-mediated motogenic effects. Taken together, these data indicate that the downregulation of c-Met signaling by BMS-777607 treatment can significantly disrupt key steps in the metastatic cascade, suggesting that such a targeting strategy may hold promise for the treatment of advanced prostate cancer.