DNA甲基化调控K562细胞系kir3dl1基因表达

DNA Methylation Regulates Kir3dl1 Gene Expression in K562 Cell Line

为分析kir3dl1基因启动子区的甲基化模式及其与基因表达的关系,探讨kir3dl1基因的表达调控机制,采用亚硫酸氢盐测序法检测K562细胞中kir3dl1基因启动子区的甲基化状况,应用甲基化抑制剂5-氮胞苷处理K562细胞以诱导CpG岛去甲基化,观察启动子区CpG岛甲基化与kir3dl1基因表达的关系。结果显示:K562细胞中kir3dl1基因核心启动子区CpG二核苷酸甲基化频率在20%-100%之间;K562细胞中kir3dl1基因启动子序列在转录因子E2F可能的结合位点上存在1个碱基的突变,并形成1个新的被甲基化的CpG二核苷酸;应用甲基化抑制剂5-氮胞苷可以诱导不表达kir3dl1基因的K562细胞重新表达该基因。结论:K562细胞中kir3dl1基因表达受启动子甲基化调控,对转录因子E2F的深入研究有助于了解其在kir3dl1基因表达调控中可能的作用。

To analyze the methylation pattern of kir3dl1 promoter and its relationship with gene expression, and to study the possible regulation mechanism of kir3dl1 gene expression, the methylation status of kir3dl1 promoter in K562 cell line was detected by bisulfite sequencing technique. Then K562 cells were treated with 5-azacytidine so as to induce demethylation of CpG island, and the relationship of CpG island methylation with kir3dl1 gene expression was investigated. The results demonstrated that CpG dinucleotides surrounding core promoter region of kir3dl1 gene was methylated at a frequency of 20% to 100% in K562 cell line. Comparison of promoter sequence with GenBank database revealed a base substitution within a putative binding site for the transcription factor E2F in K562 cell line. This mutation forms a new methylation site in kir3dl1 promoter. DNA-demethylating treatment resulted in de novo expression of kir3dl1 gene in formerly non-expressed K562 cell line. It is concluded that kir3dl1 expression in K562 cells is regulated by DNA methylation. Deeply to study E2F function contributes to profound understanding of its role in kir3dl1 gene expression regulation.