环氧化酶-2基因启动子区甲基化水平在子宫内膜异位症中的作用

Role of methylation status of the cyclooxygenase-2 gene promoter in endometriosis

目的检测环氧化酶-2(COX-2)基因启动子区CRE位点甲基化状况,探讨其在子宫内膜异位症(EMs)发生中的作用。方法收集南昌大学第一附属医院40例子宫内膜异位症患者的子宫内膜作为病例组,同期40例正常子宫内膜作为对照组,采用焦磷酸盐测序技术检测病例组和对照组子宫内膜组织中COX-2基因启动子区CRE位点甲基化频率;采用实时定量PCR及免疫组化技术分别检测病例组和对照组子宫内膜组织中COX-2 mRNA及蛋白的表达;分析COX-2基因启动子区CRE位点甲基化频率与COX-2表达水平的相关性。结果对照组内膜组织COX-2基因启动子区CRE位点的甲基化频率(40.81%±6.10%)显著高于病例组(14.74%±2.84%),P<0.05;而对照组COX-2 mRNA表达水平(0.98±0.37)及蛋白表达水平(1.00±0.73)显著低于病例组的mRNA表达水平(2.63±0.44)及蛋白表达水平(2.74±1.18),P均<0.05。随着COX-2基因启动子区CRE位点甲基化频率升高,COX-2基因表达水平下降,二者呈负相关(P<0.05)。结论 COX-2基因启动子区CRE位点去甲基化与EM s患者在位内膜COX-2高表达相关,在EM s的发生、发展中具有重要作用,提示子宫内膜异位症是一种表观遗传性疾病。

Objective To study the methylation status of CRE sites in the cyclooxygenase-2（ COX-2） gene promoter and its correlationship with endometriosis（ EMs）. Methods The endometrial tissues were collected from 40 women with laparoscopically confirmed EMs（ case group）,and 40 women without EMs（ control group）. The methylation status of COX-2 was examined by pyrosequencing. Quantitative real-time RT-PCR and immunohistochemistry were respectively performed to measure mRNA expression levels and protein levels of COX-2 in endometrial tissues. Finally,the correlation between COX-2 expression level and methylation frequencies of CRE sites were analyzed. Results The methylation frequencies of CRE sites in the COX-2 gene promoter was higher in the control group（ 40. 81% ±6. 10%） than that in the case group（ 14. 74% ± 2. 84%）,P〈0. 05. COX-2 mRNA levels（ 0. 98 ± 0. 37） and protein levels（ 1. 00 ± 0. 73） in the control group was significantly lower than the mRNA levels（ 2. 63 ± 0. 44） and protein levels（ 2. 74 ±1. 18） in the case group,both P〈0. 05. The correlation between COX-2 expression levels and methylation frequencies of CRE sites in the COX-2 gene promoter was negative（ P〈0. 05）. Conclusion The hypomethylation of CRE sites within the promoter of COX-2 may be responsible for the elevated gene expression in eutopic endometrium of EMs.