EMs患者在位子宫内膜hMLH1蛋白表达变化及其基因启动子CpG岛甲基化观察

Alteration of hMLH1 protein expression and promoter CpG island methylation of hMLH1 gene in eutopic endometria of women with endometriosis

目的观察子宫内膜异位症(EM s)患者在位子宫内膜组织中hMLH1蛋白的表达变化及hMLH1基因启动子CpG岛甲基化情况。方法采用免疫组化法分别检测52例(Ⅰ、Ⅱ、Ⅲ、Ⅳ期分别为9、16、12、15例)EM s患者及30例健康志原者(对照组)在位子宫内膜中的hMLH1,采用甲基化特异性聚合酶链反应(MSP)法检测两组在位子宫内膜hMLH1启动子CpG岛甲基化情况。分离hMLH1启动子CpG岛甲基化异常者在位内膜中的腺细胞和间质细胞,采用MSP志愿分别检测两种细胞hMLH1启动子CpG岛甲基化情况。结果 EM s组中hMLH1蛋白表达减弱共6例,其中Ⅰ、Ⅱ、Ⅲ、Ⅳ期分别为0、0、1、5例,其余样本hMLH1蛋白表达均呈阳性;对照组30例无hMLH1蛋白表达减弱者,hMLH1蛋白表达均表现为阳性。EM s组中hMLH1启动子CpG岛部分甲基化3例,其中Ⅰ、Ⅱ、Ⅲ、Ⅳ期分别为0、0、0、3例,余均表现为非甲基化;对照组30例均表现为hMLH1启动子CpG岛非甲基化。EM s组Ⅳ期患者与Ⅰ、Ⅱ、Ⅲ期患者及对照组相比,P均<0.05。3例hMLH1启动子CpG岛表现为部分甲基化者子宫内膜组织中hMLH1蛋白表达均减弱,其腺细胞中hMLH1启动子区表现为半甲基化,间质细胞hMLH1启动子区未见明显甲基化条带。结论 EM s患者在位子宫内膜组织中存在hMLH1表达减弱及hMLH1启动子CpG岛部分甲基化,主要集中在腺细胞,hMLH1异常与严重EM s的发病有关。

Objective To study the hMLH1 protein expression and promoter CpG island methylation of hMLH1 gene in endometriosis（EMs）.Methods Immunohistochemistry were used to detect the expression of hMLH1 protein of 52 cases（with 9,16,12,15 cases of Ⅰ,Ⅱ,Ⅲ,Ⅳ stage） with EMs and 30 cases healthy controls.Methylation specific polymerase chain reaction（MSP） were used to detect eutopic endometrium hMLH1 promoter CpG island methylation.Glandular cells and stromal cells in endometrial glandular of hMLH1 promoter CpG island methylation abnormalities with eutopic were separated,hMLH1 promoter methylation status of CpG islands in two types of cells were detected by MSP.Results In EMs group,1 stage Ⅲ case and 5 stage Ⅳ cases showed reduced expression of hMLH1 protein,and 3 stage Ⅳ cases showed hypermethylation of hMLH1 promoter CpG island,while the rest EMs cases and all the normal cases showed no aberrant of hMLH1.Stage Ⅳ EMs cases compared with stage Ⅰ,Ⅱ,Ⅲ and normal group,all P0.05.Expression of hMLH1 protein in the 3 cases which showed hypermethylation of hMLH1 promoter CpG island were all reduced,and promoter hypermethylation shows mainly in epithelial cells.Conclusions The expression of hMLH1 protein is decreased and hMLH1 promoter CpG island with some methylation is found in eutopic endometrial tissue of EMs patients,and mainly in glandular cells.hMLH1 abnormalities maybe related with pathogenesis of severe EMs.