Silence of hepatitis B virus X protein gene enhances sorafenib-induced apoptosis of hepatocellular carcinoma cell line PLC

Abstract

Objective To explore whether hepatitis B virus X protein (HBx) gene specific small interfering RNA (siRNA) enhances the effect of sorafenib promoting liver cancer cell line PLC apoptosis and the possible mechanism.Methods PLC cells were treated with HBx-siRNA or in combination with sorafenib.The level of HBx mRNA was assessed by using real-time quantitative polymerase chain reaction (Real-time PCR).The apoptosis rate was detected by using flow cytometry.The changes in genes profiles of mitogen-activated protein kinase (MAPK) signal pathway before and after treatment with HBx-siRNA in combination with sorafenib in PLC cells were observed by using real-time gene array.Results After treatment with HBx-siRNA for 24 h,the expression of HBx mRNA in PLC cells was decreaseed significantly to 0.61 (P ＜ 0.05).HBx-specific siRNA could enhance apoptosis of PLC cells significantly (P ＜ 0.05) and the apoptosis rate was 43％.After treatment with sorafenib in PLC cells,the expression of two genes was increased to more than two times,and that of 11 decreased to below 0.5 times in the MAPK signal pathway by using real-time PCR array.After HBx siRNA and treatment with sorafenib,the expression of one gene was increased to more than two times,and that of 37 decreased to below 0.5 times in the MAPK signal pathway by using real-time PCR array.Conclusion HBx-si RNA suppresses Hbx gene expression and enhances the response of PLC cells to sorafenib.The mechanism is related to more systemic inhibitory effect on MAPK signal pathway. Key words: Hepatitis B virus ;  Small interfering RNA ;  Sorafenib ;  Carcinoma, hepatocellular;  Mitogen-activated protein kinase signal pathway