同源异形盒A10基因启动子区甲基化及蛋白表达与子宫内膜异位症的关系

Relationship of endometriosis with methylation status in the homeobox A10 promoter region and its protein expression

目的DNA甲基化在子宫内膜异位症发病机制研究中倍受到学者们关注。文中检测子宫内膜异位症(endome-triosis,EM)患者在位和异位内膜组织中同源异形盒A10(homeobox-A10,HOXA10)基因启动子区CpG岛甲基化程度及HOXA10蛋白表达水平,探讨EM与HOXA10基因异常甲基化和蛋白表达的关系及其临床意义。方法采用甲基化特异性聚合酶链反应(MSP)和免疫组织化学法(SP法)检测36例EM患者中异位内膜组织(异位内膜组)、在位内膜组织(在位内膜组)及12例正常对照者子宫内膜组织(对照组)中HOXA10基因启动子区CpG岛甲基化状况和HOXA10蛋白表达情况。结果①36例EM患者的异位、在位内膜组织中HOXA10基因启动子区CpG岛甲基化率分别为38.9%、25.0%;其甲基化均发生在临床Ⅲ、Ⅳ期;12例正常子宫内膜组织中HOXA10基因均未发生甲基化;三组间比较差异有统计学意义(P<0.05)。②EM患者在位、异位内膜HOXA10的表达下降,无明显的分泌中、晚期峰;异位内膜基质HOXA10的表达显著降低,低于对照组正常内膜表达,其差异有统计学意义(P<0.05)。③异位内膜组织HOXA10的蛋白表达与HOXA10基因启动子甲基化呈负相关,相关系数rs=-0.368。结论EM患者异位内膜组织中存在HOXA10基因启动子区异常甲基化导致基因失活,在EM发生发展过程中起重要作用。

Objective DNA methylation in the pathogenesis of endometriosis is drawing more and more attention from the medical world. This study aimed to evaluate the methylation status of the Homeobox-A10 （HOXA10） gene promoter region and the expression of the HOXA10 protein in endometriosis, and to explore the relationship of endometriosis with the aberrant methylation and expression of HOXA10 and its clinical significance. Methods The methylation-specific PCR（MSP） and the immunohistochemical SP methods were employed to detect both the methylation status of the HOXA10 promoter and its expression in the eutopic and ectopic endometrial tissues from 36 endometriosis patients, with normal endometrial tissue samples from 12 healthy women as controls. Resuits Hypermethylation of the HOXAIO promoter region was present in 38.9% （14/36） of the ectopic endometrial tissue samples and 25.0% （9/36） of the eutopic endometrial tissue samples, all in endometriosis of stages Ⅲ and Ⅳ, but no hypermethylation was found in the endometrial tissues of the normal controls, with significant differences between the two groups （ P 〈 0.05 ）. The ectopic and eutopic endometria from the endometriosis patients failed to show similar up-regulation of the HOXA10 expression as demonstrated in the controls （P 〈 0. 05 ）. Moreover, decreased expression of HOXA10 was observed in the nuclei of stomal cells in the ectopicendometrium, with significant differences from the control samples （P 〈 0.05 ）. The expression level of the HOXA10 protein was negatively correlated with the methylation status of the HOXA10 gene promoter region in the ectopic endometrium （ rs = - 0.368 ）. Conclusion The aberrant methylation of the HOXA10 promoter region may result in the down-regulation of the gene expression in the endometrium of endometriosis women, which plays an important role in the progression of endometriosis.