DNA甲基转移酶3b基因在肝外胆管癌组织中的表达

The Expression and Significance of DNMT3b Gene in Extrahepatic Cholangiocarcinoma Tissues

目的:研究DNA甲基转移酶3b(DNMT3b)在人肝外胆管癌组织中的表达情况,并分析DNMT3b的表达与胆管癌临床病理因素之间的关系,探讨其在胆管癌发生发展过程中的作用。方法:用免疫组织化学法检测DNMT3b在24例人肝外胆管癌组织和20例慢性胆管炎组织中的阳性细胞表达率,将二者进行对比并分析其与胆管癌临床病理之间的关系。结果:(1)在24例胆管癌组织中,DNMT3b蛋白阳性细胞表达率为(46.56±12.12)%,而在20例伴慢性炎症的胆管壁组织中的阳性细胞表达率为(3.34±2.73)%,二者之间的差异具有显著性意义(P=0.000);(2)DNMT3b蛋白的异常表达与胆管癌组织的分化程度相关,低分化肿瘤的表达水平最高,其次为中等分化肿瘤,高分化肿瘤的表达水平较低。DNMT3b蛋白的异常表达与性别、年龄、肿瘤大小、肿瘤部位、有无淋巴结转移和临床分期无明显关系。结论:在胆管癌组织中,DNMT3b蛋白的表达较慢性胆管炎组织明显增加,并与肿瘤组织分化程度有关,与性别、年龄、肿瘤大小、肿瘤部位、有无淋巴结转移和临床分期无明显关系,说明DNMT3b的高表达可能与胆管癌的发生发展有关,且可能是胆管癌发生中的一个早期分子事件。

Objective：To study the expression of DNA methyltransferase 3b（DNMT3b） in human extrahepatic cholangiocarcinoma tissues,analyze the relationship between its expression and clinicopathologic features of the disease,and to explore the roles of DNMT3b during tumorigenesis and development of the disease.Methods：The expression of DNMT3b protein was detected in 24 extrahepatic cholangiocarcinoma specimens and 20 chronic cholangeitis tissue specimens by immunohistochemistry method.The results were compared between groups,and analyzed in association with clinicopatholigic features of extrahepatic cholangiocarcinoma.Results：（1） The positive cell rates of DNMT3b expression were（46.56±12.12）% and（3.34±2.73）% in extrahepatic cholangiocarcinoma specimens and in chronic cholangeitis tissues respectively.The difference between the two groups（P=0.000） was significant;（2） The expression of DNMT3b protein was correlated with differentiation grade of the carcinoma.The protein levels of DNMT3b increased progressively along with the adenocarcinoma differentiation from high to moderate,and to poor.The abnormal expression of DNMT3b protein did not correlate with gender,age,tumor sizes,tumor location,metastasis of lymph node or clinical TNM stage.Conclusions：The expression of DNMT3b protein in extrahepatic cholangiocarcinoma is significantly higher than that in chronic cholangeitis tissues.DNMT3b protein level is correlated with differentiation grade of tumor,but not correlated with gender,age,tumor size,tumor location,metastasis of lymph node,or clinical TNM stage.This result suggests that over-expression of DNMT3b may relate to the pathogenesis of biliary tract carcinoma and might be an early molecular event during genesis of biliary tract carcinoma.