Targeting of Mcl-1 Expression by MiRNA-3614-5p Promotes Cell Apoptosis of Human Prostate Cancer Cells

MicroRNA (miRNA) acts as a critical regulator of growth in various human malignancies. However, the role of miRNA-3614 in the progression of human prostate cancer remains unknown. In this study, our results demonstrated that miRNA-3614-5p exerts a significant inhibitory effect on cell viability and colony formation and induces sub-G1 cell cycle arrest and apoptosis in human prostate cancer cells. Myeloid cell leukemia-1 (Mcl-1) acts as a master regulator of cell survival. Using the miRNA databases, miRNA-3614-5p was found to regulate Mcl-1 expression by targeting positions of the Mcl-1-3′ UTR. The reduction of Mcl-1 expression by miRNA-3614-5p was further confirmed using an immunoblotting assay. Pro-apoptotic caspase-3 and poly (ADP-ribose) polymerase (PARP) were significantly activated by miRNA-3614-5p to generate cleaved caspase-3 (active caspase-3) and cleaved PARP (active PARP), accompanied by the inhibited Mcl-1 expression. These findings were the first to demonstrate the anti-growth effects of miRNA-3614-5p through downregulating Mcl-1 expression in human prostate cancer cells.