5-氮杂脱氧胞苷酸诱导ER阴性细胞ERα,ERβ恢复表达的实验研究

摘要

Objective :To investigate the effect of 5 - Aza - 2'- deoxycytidine inducing ERα , ERβ re - expression in ERα, ERβ negative MDA - MB -435 breast cancer cell line. Methods : The level of DNMT1 , ERα and ERβ mRNA in ERα, ERβ negative MDA - MB - 435 breast cancer cell line before or after treated with 5 - Aza - dC were tested by RT - PCR. Results : Compared with vehical group, cells treated with different concentration of 5 - Aza - dC ( 1 , 2. 5 , 5 , 10 , 20μmol/L ) DNMT1 mRNA expression decreased. After been exposed to 2. 5 ,5 , 10 ,20 μmol/L 5 Aza - dC respectively ERα , ERβ mRNA expression were resorted in a dose dependent manner, there was statistically diffrence( P＜0. 05 ). Conclusion: The expression of ERα, ERβ mRNA in ERα, ERβ negative breast cancer cell line coud be resorted by 5 - Aza - dC in a dose dependent manner. So, aherrant methylation was one of the main mechanisms of inducing the loss of ERα, ERβ expression.%目的:观察5-氮杂脱氧胞苷酸(5-Aza-dC)对ERα、ERβ阴性细胞株MDA-MB-435的ERα、ERβ的恢复表达作用.方法:采用不同终浓度(1、2.5、5、10、20μmol/L) 5-Aza-dC处理 ERα、ERβ阴性细胞株MDA-MB-435 96h,通过逆转录PCR(Reverse transcript PCR,RT-PCR)方法检测5'-Aza-dC处理后ER阴性MDA-MB-435乳腺癌细胞株DNMT1、ERα、ERβ mRNA变化情况.结果:不同浓度5-Aza-dC均可明显抑制DNMT1 mRNA表达,20μmol/L的5-Aza-dC对DNMT1 mRNA抑制作用最为明显;采用不同浓度5-Aza-dC处理MDA-MB-435细胞96h后,ERα、ERβ mRNA表达水平随5-Aza-dC浓度增大而增加,差别具有显著性(P<0.05).结论:DNMT抑制剂5-Aza-dC可以浓度依赖性地恢复ER阴性细胞中ERα,ERβ mRNA表达,说明ERα,ERβ基因启动子甲基化是引起ERα、ERβ蛋白失表达的重要机制之一.