MiR-345 suppresses proliferation, migration and invasion by targeting Smad1 in human prostate cancer.

INTRODUCTION: The roles of dysregulated microRNAs in prostate cancer metastasis are still unknown. In this study, we found that the expression of miR-345 was significantly downregulated in prostate cancer and clinical prostate cancer tissues.

MATERIALS, METHODS AND RESULTS: Overexpression of miR-345 in prostate cancer cells suppressed proliferation, migration and invasion. Using nude mice model, we revealed that miR-345 inhibits the growth of prostate cancer cells in vivo and in vitro. Furthermore, we identified and validated Smad1 as a direct target of miR-345. Ectopic expression of Smad1 without its 3'-UTR rescued miR-345-induced cell migration and invasion inhibition.

CONCLUSION: Taken together, our data suggest that miR-345 exerts a suppressive effect on prostate cancer proliferation, invasion and migration through downregulation of Smad1.