MicroRNA-506 inhibits cell proliferation and invasion in prostate cancer by targeting HDAC4

Accumulating evidence shows the involvement of microRNAs (miRNAs) in carcinogenesis as either oncogenes or tumor suppressor genes. miR-506 has been implicated in several human cancers, but its roles and functional mechanisms in prostate cancer (PCa) have not yet been evaluated. The present study revealed that miR-506 was markedly down-regulated in PCa cells and tumor tissues. Ectopic expression of miR-506 in PCa cells suppressed cell proliferation and invasion, induced cell cycle arrest, and promoted cell apoptosis. Furthermore, miR-506 directly reduced the expression of HDAC4 by binding to its 3'-untranslated region. Knockdown of HDAC4 mimicked the effects of miR-506, whereas re-expression of HDAC4 restored the suppressive effect of miR-506. Taken together, our results indicate that miR-506 acts as a tumor suppressor in PCa and its suppressive effects are mediated by directly targeting HDAC4.