Wnt-1在化学诱发肝癌过程中的表达及意义

Significance of expression of Wnt-1 in chemically induced liver carcinogenesis in mice

目的:检测Wnt/β-catenin信号通路中Wnt-1在化学诱发小鼠肝癌过程中的表达,揭示Wnt/β-catenin通路与肝癌发生之间的关系.方法:95只C57BL/6J♂小鼠随机分为实验组(n=50)和对照组(n=45).实验组联合二乙基亚硝胺(diethylnitrosamine,DEN)/四氯化碳(carbon tetrachloride,CCl4)/乙醇(ethanol)诱发小鼠肝癌.实验组和对照组每2周各随机抽取5只小鼠定期处死并取组织标本进行病理学观察,并通过Real-time PCR、Western blot、免疫组织化学动态监测肝组织的Wnt-1 mRNA及蛋白表达情况.结果:(1)化学诱导20 wk后,成功诱发小鼠肝癌;(2)Real-time PCR显示,Wnt-1 mRNA的表达在第4至12周实验组和同期对照组相比差异没有显著性,第14至20周实验组较同期对照组表达升高,且随着诱癌时间延长实验组第14、16、18周Wnt-1 mRNA表达逐渐升高(4.192±0.322 vs 5.630±0.579 vs 8.060±0.795,P<0.05),第18周和第20周表达差异没有显著性(8.060±0.795 vs 8.038±0.649,P>0.05);(3)Western blot显示对照组Wnt-1蛋白微弱表达;实验组Wnt-1蛋白第4至12周微弱表达,第14至18周随着诱癌时间延长Wnt-1蛋白表达逐渐升高,第18周和第20周蛋白表达差异没有显著性;(4)免疫组织化学显示,Wnt-1在实验组第8周和对照组仅见微弱表达,实验组从16 wk开始较对照组表达增加,至20 wk时表达最强.结论:Wnt-1参与了小鼠肝癌的发生发展,Wnt/β-catenin信号通路在肝癌的发生过程中可能扮演重要角色.

AIM： To detect the expression of Wnt-1 in chemi- cally induced liver carcinogenesis in mice, and to reveal the relationship between Wnt/β-catenin signaling pathway and liver cancer. METHODS： Ninety-five C57BL/6J mice were randomly divided into either an experimental group （n = 50） or a control group （n= 45）. In the experimental group, primary hepatocel- lular carcinoma （HCC） was induced by using diethylnitrosamine （DEN）, carbon tetrachloride （CCI4） and ethanol for twenty weeks. Five mice of each group were randomly sacrificed every two weeks to collect specimens. The expression of Wnt-1 mRNA and protein was dynamicallyobserved by real-time PCR, Western blot and immunohistochemistry. RESULTS： Liver cancer in C57BL/6J mice was successfully induced chemically after 20 weeks. Real-time PCR showed that the expression of Wnt-1 mRNA in the experimental group signifi- cantly increased compared to the control group at various time points during the period from weeks 14 to 20, while there was no significant difference from weeks 4 to 12. In the experimen- tal group, Wnt-1 mRNA expression increased with time from weeks 14 to 16 and 18 （4.192 ± 0.322 vs 5.630 ± 0.579 vs 8.060 ± 0.795, P 〈 0.05）, but there was no significant difference betweert weeks 18 and 20. Western blot analysis showed that Wnt-1 protein expression was weak in both groups from weeks 4 to 12, but increased with time in the experimental group, although there was also no significant difference between weeks 18 and 20. Immunohistochemistry showed that Wnt-1 was expressed weakly in both groups be- fore week 8, but began to increase from week 16 in the experimental group, peaking at week 20.CONCLUSION： Wnt-1 may be associated with the occurrence of HCC, and Wnt/β-catenin sig- naling pathway may play an important role in this process.