[Overexpression of miR-519d-3p inhibits the proliferation of DU-145 prostate cancer cells by reducing TRAF4].

Objective To observe the effect of microRNA-519d-3p (miR-519d-3p) on the proliferation of prostate cancer cells and explore the possible molecular mechanism. Methods The expression level of miR-519d-3p in PC-3, DU-145, 22RV1, PC-3M, LNCaP human prostate cancer cells and RWPE-1 human normal prostate epithelial cells was detected by real-time quantitative PCR. miR-519d-3p mimics or negative control microRNAs (miR-NC) was transfected into the prostate cancer cells with the lowest level of miR-519d-3p expression. Transfection efficiency was examined. The effect of miR-519d-3p on the cell cycle of prostate cancer was detected by flow cytometry. MTT assay and plate clone formation assay were used to detect its effect on the proliferation of prostate cancer cells. Bioinformatics software was used to predict and dual luciferase reporter assay was used to validate the target gene of miR-519d-3p. Real-time quantitative PCR was used to detect the expression of miR-519d-3p target gene. Western blot analysis was used to detect the expression of target gene protein and downstream protein. Results The expression of miR-519d-3p in normal prostate epithelial cells was significantly higher than that in prostate cancer cells, and the lowest was found in DU-145 cells. After transfected with miR-519d-3p mimics, the expression level of miR-519d-3p in DU-145 cells increased significantly. Bioinformatics prediction and dual luciferase reporter gene confirmed that tumor necrosis factor receptor associated factor 4 (TRAF4) was the target gene of miR-519d-3p. Overexpression of miR-519d-3p significantly reduced the expression of TRAF4 gene and its downstream TGF-β signaling pathway proteins in the prostate cancer cells. Conclusion The expression of miR-519d-3p is down-regulated in prostate cancer cells. Overexpression of miR-519d-3p can inhibit the proliferation of prostate cancer cells. The possible mechanism is that miR-519d-3p inhibits the expression of TRAF4.