摘要
目的探讨DNA错配修复基因MLH1(human MutL homolog1)、MSH2(human MutS homolog2)甲基化在人小细胞肺癌H446细胞获得性耐药中的作用。方法RT-PCR及Western blot法检测H446细胞及其多药耐药细胞H446/DDP中MLH1、MSH2基因的mRNA表达和蛋白表达,甲基化特异性PCR(MSP)法检测MLH1、MSH2基因启动子CpG岛甲基化状态。结果H446/DDP细胞中MLH1、MSH2基因的mRNA及蛋白水平均较H446细胞显著降低(P<0.01),且其启动子甲基化程度明显增强。结论DNA错配修复基因MLH1、MSH2启动子甲基化诱导其表达下调可能是人小细胞肺癌获得性耐药的重要机制之一。
Objective To investigate the role of methylated DNA mismatch repair gene MLH1 and MSH2 in the acquired muhidrug-resistance of human small cell lung cancer cells H446. Methods The reverse tran- scription polymerase chain reaction （ RT-PCR ） and Western blot were applied to measure MLH1 and MSH2 mRNA and protein expressions of the muhidrug-resistant cells H446/DDP and its parental cells H446. The promoter methylation status of the genes was assessed by methylation-specific PCR （MSP）. Results The expres- sions of MLH1 and MSH2 significantly decreased both in mRNA level and protein level. Promoter methylation of MLH1 was observed in H446/DDP cells but not in H446 cells. Promoter semi-methylation of MSH2 in H446 cells was transformed to methylation in H446/DDP cells. Conclusion The downregulation of DNA mismatch repair gene MLH1 and MSH2 induced by its promoter methylation may play an important role in the acquired muhidrug resistance of human small cell lung cancer.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2007年第23期2247-2249,共3页
Journal of Third Military Medical University
