Abstract: Objective · To investigate the effects of ribosomal protein 16 (RPS16) on tumorigenesis and development of prostate cancer. Methods · Western blotting (WB) was used to detect the differences of RPS16 levels in 25 cases of prostate cancer tissues and 33 prostate hyperplasia, and immunohistochemistry (IHC) was performed to detect RPS16 levels in 48 prostate cancer tissues and 42 benign tissues. The relationship betweenRPS16 level and clinical pathological parameters of the patients was analyzed. The RPS16 small interfering RNA (siRNA) was transiently transfected into DU145 and LNCaP cellsliposome method, including RPS16-siRNA1, RPS16-siRNA2 and RPS16-siRNA3. Random disturbance RPS16-siRNA-NC was used as negative control, cells without transfection were blank control. The efficiency of RNA interference was detectedWB 48-72 h after transfection. RPS16-siRNA with highest efficiency was chosen for subsequent cell proliferation assay, flow cytometry (FCM) and transwell assay into detect the effects of RPS16 on cell proliferation, cell cycle and invasion ability of DU145 and LNCaP cells. Results · WB results showed that the level of RPS16 protein in the tissues of prostate cancer was higher than that of the benign group (P0.008). IHC results showed RPS16 protein level was significantly higher in tumor tissues than benign tissues (P0.009). RPS16 was not correlated with age and metastasis, but significantly correlated with clinical stage (P0.044) and pathological grade of the tumor (P0.004). RPS16 siRNA can not only significantly reduce the ofRPS16 protein in DU145 and LNCaP cells, but also inhibit the proliferation and invasion of the cancer cells, so that the cell cycle arrested in G2/M phase. Conclusion · The high of RPS16 protein could enhance the proliferation and invasive ability of prostate cancer cells.

Key words: ribosomal protein 16, prostate cancer, RNA interference , invasion, proliferation