微小RNA-205在非小细胞肺癌中的表达及其启动子甲基化情况

摘要

目的 探讨微小RNA-205(miR-205)在非小细胞肺癌(NSCLC)中的表达及其启动子甲基化情况.方法 采用实时荧光定量PCR法对27份NSCLC组织及其癌旁正常组织标本的miR-205进行相对定量分析,其中肺腺癌组织19份,肺鳞癌组织8份.先对RNA-205基因启动子区CpG岛进行预测,再经亚硫酸盐测序、PCR产物克隆、鉴定、测序等步骤,分析并比较人肺鳞癌细胞株HTB-182和人肺腺癌细胞株A549的miR-205基因启动子区域甲基化水平.结果 肺腺癌组织miR-205的表达量高于癌旁组织(P＜0.05),肺鳞癌组织的miR-205表达量高于癌旁组织(P＜0.05);肺鳞癌组织miR-205表达量高于肺腺癌组织(P＜0.05).miR-205基因的启动子具有CpG岛,与肺腺癌A549细胞相比,肺鳞癌HTB-182细胞的miR-205基因启动子的甲基化程度较低(P＜0.05),且主要差别体现在Site2和Site6上.结论 肺鳞癌的miR-205表达水平升高,这可能与其启动子低甲基化有关.%Objective To investigate the microRNA-205(miR-205) expression and its methylation promoter in non-small cell lung cancer(NSCLC).Methods Relative quantitative analysis was performed for miR-205 in 27 cases of NSCLC tissues and paired normal lung tissues(19 of lung adenocarcinoma tissues and 18 of lung squamous carcinoma tissues) by real-time quantitative PCR.To predict the CpG island in RNA-205 gene promoter region. The methylation levels of miR-205 gene promoter in human lung squamous carcinoma cell line HTB-182 and human lung adenocarcinoma cell line A549 were analyzed and compared by bisulfite sequencing,PCR product cloning,identification and sequencing. Results No statistically significant difference was found in the expression of miR-205 between lung adenocarcinoma tissues and adjacent tissues(P＜0.05),and the expression of miR-205 in the lung squamous carcinoma tissues was higher than that in the adjacent tissues(P＜0.05);the expression of miR-205 in the lung squamous carcinoma tissues was higher than that in the lung adenocarcinoma(P＜0.05).CpG islands was found in miR-205 gene promoter,the methylation level of miR-205 gene promoter in the lung squamous carcinoma HTB-182 cells was lower than that in the lung adenocarcinoma A549 cells(P＜0.05),and the main differences were reflected in Site2 and Site6.Conclusion The elevated expression level of miR-205 is observed in the lung squamous carcinoma,which might correlate with the lower methylation of miR-205 promoter.