食管癌细胞系中MT-3基因CpG岛甲基化的意义

Significance of CpG Island Methylation of MT-3 gene in Cell Lines of Esophageal Cancer

目的研究食管癌细胞系中MT-3基因CpG岛甲基化与其mRNA表达的关系。方法选取4种食管癌细胞系OE21,OE19,OE33和TE7,经重亚硫酸钠处理后,采用限制性酶切图谱分析(COBRA)和逆转录聚合酶链反应(RTPCR)技术,在DNA甲基转移酶抑制剂5氮2’脱氧胞苷(5azaCdR)处理前后,对其MT-3基因CpG岛的甲基化情况及mRNA的表达情况进行对比研究。结果4种食管癌细胞系的MT-3基因均存在不同程度的CpG岛超甲基化。经5azaCdR处理后,超甲基化状态解除,mRNA的表达水平也较处理前明显提高(P=0.002)。结论食管癌细胞系中MT-3基因CpG岛的超甲基化可抑制其mRNA表达。当其超甲基化解除后,MT3基因的mRNA表达水平也会相应升高。

Objective To study the relationship between CpG island methylation of MT-3 gene and its mRNA expression in cell lines of esophageal cancer.Methods Four cell lines of esophageal cancer,OE21,OE19,OE33 and TE7,were used in this study.The CpG island methylation and the mRNA expression of MT-3 gene of the four cell lines were tested by techniques of combined bisulfite restrict analysis(COBRA) and RT-PCR before and after the treatment of inhibitor of DNA methyltransferase,5-Aza-2'-deoxycytidine(5-aza-CdR).Results CpG island hypermethylation of MT-3 gene existed in all the four cell lines of esophageal cancer.The hypermethylation was demethylated and the mRNA expression increased markedly(P=0.002) after the treatment of 5-aza-CdR.Conclusion CpG island hypermethylation of MT-3 gene in cell lines of esophageal cancer inhibits their mRNA expression.When the hypermethylation is demethylated,the mRNA expression gets a corresponding increase.