散发性大肠癌O6-甲基鸟嘌呤-DNA甲基转移酶基因启动子过甲基化状况及K-ras表达与临床病理特征相关性分析  

The promoter hypermethylation of O6-methylguanine-DNA methyltransferase gene and expression of K-ras in human sporadic colorectal cancers

作　　者：牛钊锋 

机构地区：[1]山西省运城市中心医院,044000

出　　处：《实用医技杂志》2012年第2期125-128,共4页Journal of Practical Medical Techniques

摘　　要：目的探讨散发性大肠癌中DNA修复酶O6-甲基鸟嘌呤-DNA甲基转移酶(MGMT)的过甲基化状况、K-ras的表达及其相关性。方法采用甲基化特异性PCR(MSP)及免疫组织化学的方法,检测130份病理证实的散发性大肠癌患者癌组织MGMT基因过甲基化状况、K-ras的表达及它们的相关性。结果在130例散发性大肠癌组织中MGMT基因启动子甲基化率35%,K-ras的阳性表达率47%,呈正相关(r=0.765,P<0.01)。在分化程度低、淋巴结转移、肥胖、P-TNM分期Ⅲ～Ⅳ期的患者中,MGMT基因过甲基化率较高,K-ras的阳性表达率亦高。另外K-ras的阳性表达在腺癌中高于非腺癌类型。结论在散发性大肠癌中,MGMT基因启动子甲基化可能导致K-ras基因的激活,共同参与散发性大肠癌的发生、发展。Objective To explore the relationship between the promoter hypermethylation of O6-methylguanine DNA methyltransferase（MGMT） gene and expression of K-ras in sporadic colorectal cancers.Methods Methylation specific PCR（MSP） and immunohistochemistry were applied to test the promoter hypermethylation of MGMT gene and expression of K-ras.Results The rate of the promoter hypermethylation of MGMT gene in 130 cases was 35%,the expression of K-ras was 47%,there was positive correlation between the expression of MGMT and K-ras in sporadic colorectal cancers（r=0.765,P0.01）.The promoter hypermethylation rate of MGMT and the expression of K-ras was higher in the differation lower,Ⅲ～Ⅳ,with lymph node group and fatty patients.The expression of K-ras in adnocarcimona was significant higher than in adenocarcinoma samples.Conclusion The promoter hypermethylation of MGMT gene and the expression of K-ras may take part in sporadic colorectal cancers evolvement.

关 键 词：O(6)-甲基鸟嘌呤DNA-甲基转移酶 DNA甲基化 聚合酶链反应 免疫组织化学 基因 

分 类 号：R735.34[医药卫生—肿瘤]