四氯化碳/乙醇诱导乙型肝炎病毒转基因小鼠发生肝纤维化与肝癌的实验观察

目的 观察四氯化碳/乙醇诱导乙型肝炎病毒转基因小鼠实验性肝纤维化和肝癌的过程.方法 采用四氯化碳/乙醇分别诱导野生型小鼠、乙型肝炎病毒X蛋白(HBx)转基因小鼠、HBsAg转基因小鼠20周,观察每组小鼠发生肝纤维化和肝癌的情况,并采用RT-PCR方法检测HBx及HBsAg基因的表达.结果 转基因小鼠肝脏有HBx或HBsAg基因表达,而野生型小鼠则没有.3组小鼠之间及雌、雄性之间发生肝纤维化的程度差异无统计学意义.四氯化碳/乙醇诱导显著加快了HBx和HBsAg转基因小鼠发生实验性肝癌的进程,雄性小鼠肝癌发生率显著高于雌性小鼠.结论 HBx和HBsAg基因整合进小鼠肝脏细胞内并不能增加肝纤维化程度,但能促进肝癌的发生发展;雄性小鼠较雌性更易发生肝癌;四氯化碳/乙醇诱导能显著促进乙型肝炎病毒转基因小鼠发生肝癌.四氯化碳/乙醇诱导乙型肝炎病毒转基因小鼠形成肝癌是一个较好的肝癌动物模型.

Observation on experimental liver fibrosis and hepatic carcinogenesis of HBV gene knock-in transgenic mice induced by CCl_4/ethanol

Objective To study the effects of carbon tetrachloride (CCl_4)/ethanol induction upon experimental liver fibrosis and hepatic carcinogenesis of HBV transgenic mice. Methods The wild-type mice, p21-HBx transgenic mice with integration of p21 locus by HBx gene and p21-HBsAg transgenic mice with integration of p21 locus by HBsAg gene were induced separately by CCl_4/ethanol twice weekly for 20 weeks. The investigators observed the development of liver fibrosis and hepatic carcinogenesis in three groups and detected the gene expressions of HBx and HBsAg by RT-PCR. Results The expression of HBx or HBsAg mRNA existed in both control and induced transgenic mice, but in none of wild-type mice. Comparing with wild-type mice, p21 genes was not expressed in livers of transgenic mice. After induction by CCl_4/ethanol, the fibrotic degrees of liver were not significantly different among wild-type mice, p21-HBx transgenic mice and p21-HBsAg transgenic mice, as well as between male and female mice. Reversely, the p21-HBsAg) were higher than that of wild-type mice. And the incidence rate of hepatic carcinogenesis in males was also markedly higher than that in females. Induction by CCl_4/ethanol markedly promoted and accelerated hepatic carcinogenesis in transgenic mice. Conclusions Integration of HBsAg and HBx genes into the murine p21 locus can significantly promote the progression of hepatic carcinogenesis, but failed to promote the progression of liver fibrosis. The male mouse is more likely to develop experimental hepatocellular carcinoma than the female mouse. Experimental hepatocellular carcinoma induced by CCl_4/ ethanol in p21-HBx and p21-HBsAg transgenic mice is a feasible animal model.