肺癌组织中错配修复基因hMLH1启动子甲基化状态分析

Status of methylation of promoter of mis match repair gene hMLH1 in lung cancer

目的 探讨肺癌组织中错配修复基因hMLH1启动子甲基化状态及其与蛋白表达的关系。方法 用HpaⅡ酶切PCR及SP免疫组织化学方法 ,分析 5 0例肺癌标本hMLH1启动子甲基化状态及蛋白表达。结果 hMLH1启动子甲基化有 16例 ,占 32 0 % (16 /5 0 )。hMLH1启动子甲基化与性别、吸烟状态及临床病理无明显的相关性。hMLH1蛋白表达阴性的 14例中 ,11例有甲基化 (78.6 % ) ;而 32例蛋白表达阳性者中 ,只有 5例甲基化 (15 .6 % )。结论 hMLH1启动子区在肺癌组织中有中等频率的甲基化 。

Objective To study the relationship between status of methylation of hMLH1 promoter and expression of its protein in lung cancer. Methods Methylation of the hMLH1 gene promoter and hMLH1 protein was examined in 50 primary lung cancer tissues by HpaⅡ digestion PCR and immunohistochemistry. Results The incidence of the hMLH1 promoter methylation was 32.0%(16/50). Methylation frequeney did not correlate with sex, smoking and clinicopathological characteristics. Negative expression of hMLH1 protein occurred in 14/46 tumors, of which 11 tumors had hMLH1 promoter methylation (78.6%, 11/14), while only 5 had methylation in 32 specimens positive for hMLH1 protein expression.Conclusion In about one third of lung cancer tissues examined there exists methylation of hMLH1 promoter, which correlates well with the absence of expression of hMLH1 protein.