5-aza-2'-deoxycitydine诱导胃癌细胞系TIMP3基因去甲基化和转录上调的实验性探讨

Experimental Studies on 5-aza-2'-deoxycitydine Induction for Demethylation and Up-regulated Transcription of Human Gastric Cancer Cell Lines TIMP3 Gene

摘要: 目的:研究人类胃癌细胞系中5-aza-2'-deoxycitydine诱导肿瘤抑制基因TIMP3mRNA和蛋白表达。方法:DNA甲基化抑制剂5-aza-2'-deoxycitydine处理人类胃癌细胞系SGC-7901。应用RT-PCR和Western-Blot方法检测TIMP3基因mRNA和蛋白表达。应用MSP分析TIMP3基因启动子甲基化状态。结果:5-aza-2'-deoxycitydine诱导TIMP3基因启动子去甲基化,上调TIMP3mRNA和蛋白表达。结论:甲基化异常是胃癌细胞TIMP3基因失活的原因之一,并可受去甲基化制剂调控表达。

Abstract: Objective: To investigate the effects of DNA methylation on cells. Methods: Gastric cancer cell lines (SGC-7901) was treated with DNA methyltransferase (DNMT) inhibitor, 5-aza- 2'-deoxycytidine (5-aza-dC). The expression of TIMP3 genes mRNA was detected using reverse transcription PCR (RT-PCR). The proteinum expression was analyzed by the Western-Blot method. DNA methylation status of TIMP3 gene promoter was assayed by MSP (methylation-specific PCR). Results: 5-aza-dC induced the demethylation of the TIMP3 gene promoter. The TIMP3 mRNA and proteinum expressions were obviously up-regulated by treatment with 5μmol/L for 24 hours. Conclusions: The hypermethylation of promoter region in CpG islands is a main mechanism of TIMP3 gene silencing in human gastric cancer cell, and may be controlled by demethylating agent 5-aza-dC.