Androgen-induced TMPRSS2 activates matriptase and promotes extracellular matrix degradation, prostate cancer cell invasion, tumor growth and metastasis

Dysregulation of androgen signaling and pericellular proteolysis are necessary for prostate cancer (PCa) progression but the links between them are still obscure. In this study, we show how the membrane-anchored serine protease TMPRSS2 stimulates a proteolytic cascade that mediates androgen-induced PCa cell invasion, tumor growth and metastasis. We found that matriptase serves as a substrate for TMPRSS2 in mediating this pro-invasive action of androgens in PCa. Further, we determined that higher levels of TMPRSS2 expression correlates with higher levels of matriptase activation in PCa tissues. Lastly, we found that the ability of TMPRSS2 to promote PCa tumor growth and metastasis was associated with increased matriptase activation and enhanced degradation of extracellular matrix nidogen-1 and laminin β1 in tumor xenografts. In summary, our results establish that TMPRSS2 promotes the growth, invasion and metastasis of prostate cancer cells via matriptase activation and extracellular matrix disruption, with implications to target these two proteases as a strategy to treat prostate cancer.