Abstract

Abstract TMPRSS2 is an androgen-regulated cell-surface serine protease expressed predominantly in prostate epithelium. TMPRSS2 is expressed highly in localized high-grade prostate cancers and in the majority of human prostate cancer metastases. Through the generation of mouse models with a targeted deletion of Tmprss2, we demonstrate that the activity of this protease regulates cancer cell invasion and metastasis to distant organs. By screening combinatorial peptide libraries, we identified a spectrum of TMPRSS2 substrates that include pro-hepatocyte growth factor (HGF). HGF activated by TMPRSS2 promoted c-MET receptor tyrosine kinase signaling, and initiated a proinvasive epithelial-to-mesenchymal transition phenotype. Chemical library screens identified a potent bioavailable TMPRSS2 inhibitor that suppressed prostate cancer metastasis in vivo. Together, these findings provide a mechanistic link between androgen-regulated signaling programs and prostate cancer metastasis that operate via context-dependent interactions with extracellular constituents of the tumor microenvironment. Significance: The vast majority of prostate cancer deaths are due to metastasis. Loss of TMPRSS2 activity dramatically attenuated the metastatic phenotype through mechanisms involving the HGF–c-MET axis. Therapeutic approaches directed toward inhibiting TMPRSS2 may reduce the incidence or progression of metastasis in patients with prostate cancer. Cancer Discov; 4(11); 1310–25. ©2014 AACR. See related commentary by Rubin, p. 1262 This article is highlighted in the In This Issue feature, p. 1243