肺癌E-cadherin基因启动子CpG岛甲基化与蛋白表达的关系及其意义  

The relation between E-cadherin promoter CpG island methylation and E-cadherin protein expression in lung cancer

作　　者：王红兵[1] 苗慧[1] 张敬川[1] 祖茂衡[3] 蔡晓敏 吴秀英 胡西旦 迪力努 陈春玲 

机构地区：[1]徐州医学院附属医院肿瘤科,江苏徐州221002 [2]新疆伊犁州新华医院内科,新疆伊宁835000 [3]徐州医学院附属医院介入科

出　　处：《中国癌症杂志》2007年第8期603-606,共4页China Oncology

摘　　要：背景与目的:目前认为CpG岛甲基化导致转录抑制是恶性肿瘤发生的重要机制之一。E-cadherin能抑制肿瘤细胞的浸润和转移,被公认为是浸润、转移抑制基因。本研究检测肺癌组织中E-cadherin基因启动子CpG岛甲基化的状况,并探讨基因异常甲基化与蛋白表达的关系及其意义。方法:采用甲基化特异性PCR技术,检测22例肺癌组织,相应的癌旁组织和9例正常肺组织中E-cadherin基因启动子CpG岛甲基化的状况。采用免疫组化S-P法相应检测了E-cadherin蛋白的表达。结果:肺癌中E-cadherin基因启动子CpG岛完全甲基化率为13.6%(3/22),部分甲基化率为27.3%(6/22),总甲基化率为40.9%(9/22),显著高于相应癌旁组织中该基因的甲基化率9.1%(2/22)(P<0.05)。9例正常肺组织中未检测到此基因的甲基化(0/9)。22例癌组织中E-cadherin蛋白表达减弱或缺失率59.1%(13/22),显著高于相应癌旁组织蛋白表达减弱缺失率27.3%(6/22)。肺癌组织中发生甲基化者蛋白表达率及强度明显低于未甲基化者。结论:肺癌组织中存在E-cadherin基因启动子CpG岛的异常甲基化,E-cadherin基因启动子CpG岛的异常甲基化可能是E-cadherin蛋白表达下调的主要原因。Background and purpose-Transcriptional silencing by CpG island methylation is now believed to be an important mechanism of carcinogenesis. E-cadherin can suppress tumor cell invasion and metastasis, and is considered as an invasion/metastasis suppressor gene. We detected the methylation pattern of the E-cadherin gene in lung cancer, and evaluated its possible correlation with the expression of E-cadherin protein, and explored the mechanism of lung carcinogenesis. Methods： The tissue specimens from 22 cases of lung cancer, adjacent lung tissues and 9 cases of normal tissues were examined and CpG island methylation of E-cadherin gene was detected by methylation specific PCR. The expression of E-cadherin was evaluated by immunohistochemistry S-P staining method. Results： The positive rate of E-cadherin hypermethylation in lung tumor tissues was significantly higher than that in the adjacent lung tissues （40.9% vs. 9.1% , P 〈0.05）. The incidence of promoter hypermethylation was not found in 9 benign lung disease tissues. There were 13 of 22 cases showing E-cadherin weak expression or absence in lung cancer that was significantly higher than adjacent lung tissues（ 6/ 22）. The patients with E-cadherin promoter methylation showed lower expression of E-cadherin than those without E-cadherin promoter methylation in lung cancer. Conclusions： Methylation of E-cadherin gene is commonly seen in lung cancer. Methylation of E-cadherin promoter may play an important role in the down-regulation of E-cadherin expression.

关 键 词：肺癌 E-CADHERIN CPG岛 甲基化 MSP 

分 类 号：R735.2[医药卫生—肿瘤]