Influence Of SiRNA Silencing Expression Of Livin Gene On The Proliferation And Apoptosis Of HepG2Cells

Background and objective:liver cancer is common malignancy tumor in China in recent years,the incidence of the disease tends to increase.The surgical resection is still the most effective treatment method to the liver cancer. Multiple genes are involved in the development of liver cancer at different time. RNA interference (RNA interference, RNAi) is present in the eukaryotic organisms within a self-defense system to block the expression of exogenous genes, which is mediated by double-stranded RNA and enables the specific complementary single RNA degradation. In recent years, a series studies reported that RNAi specificly suppressed liver cancer related genes, bringing new hope and revelation for liver cancer research and targeted therapy. Livin is also called KIAP (kidney inhibitor of apoptosis protein) and ML-IAP (melanoma inhibitor of apoptosis protein), a new member of the inhibitor of apoptosis protein family, Recent studies have shown that it is overexpressed in a variety of solid tumors and cancer cell lines and participated in the development of tumor. In this study, silence expression of Livin gene in hepatocellular carcinoma cell line HepG2by RNA interference was induced to determine the influence of Livin gene on HepG2cells proliferation, apoptosis, and cell cycle, which can provide a experimental basis for the Livin gene as target gene therapy of liver cancer.Methods:HepG2cells were transfected with synthetic small interfering RNA (siRNA) targeting Livin. Expression of Livin mRNA and protein were respectively measured by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Flow cytometry (FCM) and TUNEL assay were used to examine cell cycle and apoptosis in transfected cells. Statistical analysis was performed using SPSS15.0statistical software, the results of the measurement data to±+s, using analysis of variance and t test,P≤0.05was considered significant standard.Results:The livin gene is highly expressed in HepG2cells, which has inhibitory effect on cell apoptosis.After transfection of livin-siRNA, The result of RT-PCR and Western blot showed that the mRNA and protein levels of Livin declined markedly in transfected cells, there were statistically significant compared with negative control group and mock group.After transfection of livin-siRNA, FCM demonstrated that the cell cycle was arrested in the G1phase and early apoptosis rate increased, there were considerable differences compared with negative control group and mock group.After transfection of livin-siRNA, the result of TUNEL assay indicated that the number of apoptotic cells in transfected group obviously increased,there were significant differences compared with negative control group and mock group.Conclusions:Livin gene is highly expressed in hepatocellular carcinoma cells,participates in the occurrence and development of hepatocellular carcinoma.Livin-siRNA can down-regulate the expression of Livin gene and protein in hepatocellular carcinoma HepG2cells.siRNA-mediated downregulation of Livin expression can induce apoptosis and diminish the growth, proliferation in hepatocellular carcinoma HepG2cells.