目的检测Wnt/β-catenin信号通路中Axin-1在化学诱导C57BL/6J小鼠肝癌模型发生过程中的表达水平,揭示Wnt/β-catenin通路与肝癌发生的关系。方法95只C57BL/6J小鼠随机分为实验组50只和对照组45只。实验组小鼠以联合二乙基亚硝胺(DEN)/四氯化碳(CCl4)/乙醇诱导建立小鼠肝癌模型,对照组未予任何特殊处理。每2周定期处死两组小鼠各5只,并取肝组织进行病理学观察,以实时荧光定量PCR(RT—PCR)技术、Western blot法、免疫组化法检测并动态观察Axin-1 mRNA和蛋白水平的表达情况。结果小鼠经化学诱导20周后成功诱发小鼠肝癌并建立小鼠肝癌模型。RT—PCR和Western blot法检测显示,Axin-1 mRNA和蛋白水平的表达在诱导的第4周至第14周,实验组和同期对照组比较差异无统计学意义(P〉0.05);在诱导的第16周至第20周实验组和同期对照组比较差异有统计学意义(P〈0.05),且随着诱癌时间的延长,实验组Axin-1的表达逐渐降低,在诱导的第16周、第18周和第20周Axin-1 mRNA的相对表达量分别为0.421±0.083、0.278±0.042、0.120±0.028(P〈0.05)。免疫组化法检测显示Axin-1在对照组各诱导期均为阳性表达,实验组从第16周开始Axin-1的表达减弱,至第20周时Axin-1几乎不表达。结论Wnt/β-catenin信号通路可能与肝癌的发生、发展有关,其中Axin-1可能起着负性调节的作用。
Objective To analyze the expression of Axin-1 during chemical induction of liver cancer in C57BL/6J mice. Methods C57BL/6J mice were divided randomly into an experimental group (n=50)and a control group (n=45).Mice in the experimental group were treated with diethylnitrosamine (DEN),carbon tetrachloride (CCL) and ethanol for 20 weeks to induce hepatocellular carcinoma (HCC).Every 2 weeks ,5 mice in each group were sacrificed and liver samples were taken.Dynamic expression of Axin-1 was analyzed using real-time PCR,Western blotting and immunohistochemistry,while pathological changes were analyzed using hematoxylin staining. Results The 20-week DEN/CCh/ethanol treatment successfully induced liver cancer in C57BL/6J mice.Based on real-time PCR and Western blotting,expression of Axin-1 mRNA and protein was significant/y lower in the experimental group than in the control group between weeks 16 and 20.This expression decreased gradually over time in the experimental group:levels of mRNA were 0.421±0.083 at week 16,0.278±0.042 at week 18 and 0.120±0.028 at week 20 (P〈0.05).Immunohistoehemistry showed detectable levels of Axin-1 staining in the control group at all time points tested; in the experimental group ,however,the level of staining began to decrease at week 16 and was nearly undeteetable at week 20. Conclusion The Wnt/β-catenin signaling pathway may be associated with HCC development, with Axin-1 acting to inhibit HCC progression.