干扰素诱导肝癌细胞ADAR1的表达模式及HBV复制抑制

Effect of interferons on expression of adenosine deaminase acting on RNA 1 and hepatitis B virus replication in human hepatocellular carcinoma cells in vitro

目的探讨Ⅰ型干扰素(IFN-α、IFN-β)和Ⅱ型干扰素(IFN-γ)在肝癌细胞中诱导ADAR1(P110和P150)的表达模式及对HBV复制的作用。方法不同浓度IFN-α(0、200、500、1 000、2 000 U/mL)、IFN-β(0、200、1 000 U/mL)和IFN-γ(0、200、1 000 U/mL)分别处理肝癌细胞(Huh7和HepG2),Western blot和RT-qPCR检测肝癌细胞中IFN作用后ADAR1的表达变化;Huh7细胞瞬时转染HBV复制型质粒,IFN-α作用后,Southern blot分析HBV DNA复制中间体水平。结果Ⅰ型IFN(IFN-α、IFN-β)作用Huh7和HepG2细胞后,ADAR1 P110蛋白水平增加(P<0.05),同时ADAR1 P150表达水平明显增高(P<0.01),且ADAR1 P150的表达呈现IFN浓度依赖性;Ⅱ型IFN(IFN-γ)作用Huh7和HepG2细胞后,ADAR1 P110和P150蛋白表达水平没有发生明显变化。IFN-α明显抑制Huh7细胞中HBV复制(P<0.05),与浓度梯度呈负相关。结论Ⅰ型IFN可诱导肝癌细胞中ADAR1 P150表达,IFN-α抑制Huh7细胞中HBV复制,其作用可能与ADAR1相关。

Objective To investigate the effect of type Ⅰ interferons(IFN-α and IFN-β) and type Ⅱ interferon(IFN-γ) on the expression of adenosine deaminase acting on RNA 1(ADAR1, P110 and P150) and hepatitis B virus(HBV) replication in hepatocellular carcinoma(HCC) cells. Methods Western blotting and qRT-PCR were used to detect the expression of ADAR1 in human HCC cell lines HepG2 and Huh7 following treatment with different concentrations of IFN-α, IFN-β or IFN-γ. Southern blotting was employed to detect the changes in HBV DNA level in response to IFN-α treatment in Huh7 and HepG2 cells transfected with HBV replication plasmids. Results In Huh7 and HepG2 cells, treatments with IFN-α and IFN-β significantly increased the protein expression of ADAR1 P150 in a time-and dose-dependent manner(P<0.01) and also obviously augmented the protein level of ADAR1 P110;IFN-γ did not significantly affected the expression of either ADAR1 P110 or ADAR1 P150. IFN-α treatment dose-dependently inhibited HBV DNA replication in Huh7 cells(P<0.05). Conclusion Type Ⅰ interferons time-and dose-dependently increase the expression of ADAR1 in Huh7 and HepG2 cells, suggesting a possible role of ADAR1 in mediating the anti-HBV effect of IFN-α.