胃癌中IRX1的表达与启动子区甲基化的相关性

Correlation between expression of IRX1 gene and promoter site methylation status in gastric cancer

目的探讨胃癌中同源盒基因IRX1的表达与启动子区甲基化修饰之间的关系。方法生物信息学软件分析IRX1基因启动子区;RT-PCR检测胃癌细胞株及手术切除胃癌组织IRX1基因mRNA表达水平;MSP及BSP法检测启动子区甲基化状态;检测去甲基化试剂5-杂氮-2’-脱氧胞苷的干预对胃癌细胞IRX1基因表达的逆转效应。结果经生物信息学预测IRX1基因转录起始点上游启动子区富含CpG岛;胃癌细胞株及胃癌组织IRX1基因表达有不同程度下调;MSP及BSP检测显示所有胃癌细胞株启动子区呈高甲基化状态;经5-Aza-CdR处理的细胞株IRX1基因的表达有不同程度上调。结论胃癌中IRX1基因的表达下调与启动子区甲基化修饰有一定关系,为探讨IRX1基因作为去甲基化治疗靶点的可能性提供了实验数据。

Objective To explore the possible relationship between hypermethylation of iroquois homeobox protein 1 （IRX1） gene promoter site and gene expression in gastric cancer. Methods The bioinformaties software was used to analysis promoter site of IRX1 gene. RT-PCR was employed to detect gene expression level of gastric cancer cell lines and reseeted gastric cancer tissues. The methylation status of gene promoter site was analyzed by methylation speeific-PCR （MSP） and bisulfite sequenee-PCR （BSP） methods. DNA methylation inhibitor 5-Aza-2＇-deoxyeytidine was used on gastric cancer cell lines and then IRX1 gene expression was detected. Results Bioinformaties analysis displayed that promoter site of IRX1 gene showed abundant CpG island. The IRX1 gene expression was down-regulated both in gastric cancer cell lines and gastric cancer tissues. Hypermethylation status of promoter site was found in all the gastric cancer cell lines by MSP and BSP methods. The gene expression was up-regulated after 5-Aza-CdR treatment. Conclusion The downregulated expression of IRX1 in gastric cancer may be correlated with the hypermethylation of promoter site. The result provides some evidence that IRX1 may act as a potential therapeutic target in demethylation treatment.