MicroRNA-195 suppresses tumor cell proliferation and metastasis by directly targeting BCOX1 in prostate carcinoma.

Elucidation of the downstream targets regulated by the metastasis-suppressive miRNAs can shed light on the metastatic processes in prostate cancer (PCa). We conducted microarray analyses and found that miR-195 was significantly decreased in metastatic PCa. Low miR-195 expression is an independent prognostic factor for poor biochemical recurrence-free and overall survival. Forced expression of miR-195 in PCa cells drastically inhibits proliferation, migration and invasion in vitro and inhibits tumor growth and metastasis in vivo. BCOX1 is identified as a direct target of miR-195 in PCa, and is found to be drastically increased in metastatic PCa. BCOX1 knockdown phenotypically copies miR-195-induced phenotypes, whereas forced expression of BCOX1 reverses the effects of miR-195. Collectively, this is the first report unveils that loss of miR-195 expression and thus uncontrolled BCOX1 upregulation might drive PCa metastasis.