miR-202 suppresses prostate cancer growth and metastasis by targeting PIK3CA.

MicroRNA (miR)-202 has been reported to be involved in the regulation of human cancer progression including bladder cancer, non-small cell lung cancer, pancreatic cancer and esophageal squamous cell carcinoma. However, the function of miR-202 in prostate cancer remains largely unknown. The present study demonstrated that miR-202 was downregulated in human prostate cancer tissues and cell lines. And overexpression of miR-202 significantly inhibited the proliferation, migration and invasion of prostate cancer cells, but induced cell apoptosis. Moreover, miR-202 suppressed tumor growth in vivo. Regarding the underlying mechanism, it was revealed that phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit α (PIK3CA) was a target gene of miR-202 in prostate cancer cells. Overexpression of miR-202 inhibited the mRNA and protein levels of PIK3CA in prostate cancer cells. Moreover, overexpression of PIK3CA abolished the inhibitory effects of miR-202 on prostate cancer cell proliferation, migration and invasion in vitro. Taken together, these findings demonstrated that miR-202 served as a tumor suppressor in prostate cancer by directly targeting PIK3CA.