启动子甲基化调控NK-92MI细胞KIR3DL1基因表达

目的:观察NK细胞系NK-92MI细胞中KIR3DL1基因启动子区的甲基化模式及去甲基化和组蛋白乙酰化对基因表达的影响,探讨KIR3DL1基因的表达调控机制.方法:采用亚硫酸氢盐测序法检测NK-92MI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-氮胞苷和(或)组蛋白去乙酰化转移酶抑制剂曲古抑菌素A处理NK-92MI细胞以诱导CpG岛去甲基化和组蛋白乙酰化,观察启动子区CpG岛甲基化和组蛋白乙酰化与KIR3DL1基因表达的关系.结果:NK-92MI细胞中KIR3DL1基因启动子区高甲基化,CpG二核苷酸甲基化频率在70%～100%之间;应用终浓度为2.5 μmol/L和5 μmol/L的5-氮胞苷作用72 h可以诱导NK-92MI细胞中KIR3DL1 mRNA表达量分别增加66.6%和114.6%;单用终浓度为50 nmol/L的曲古抑菌素A不能诱导NK-92MI细胞中KIR3DL1 mRNA表达量增加;此外,曲古抑菌素A和5-氮胞苷联用与单用5-氮胞苷相比也没有协同作用.结论:NK-92MI细胞中KIR3DL1基因表达受启动子甲基化调控.

Promoter methylation regulates KIR3DL1 gene expression in NK-92MI cell line

AIM: To investigate the methylation pattern of KIR3DL1 promoter region in NK cell line NK-92MI and the effect of demethylation and histone acetylation on gene expression, and to study the possible regulation mechanism of KIR3DL1 expression. METHODS: The methylation status of KIR3DL1 promoter in NK-92MI cells was detected by bisulfite sequencing technique. Then NK-92MI cells were treated with the DNA-demethylating compound 5-azacytidine and (or) the inhibitor of histone deacetylase trichostatin A, and the expression of KIR3DL1 gene was observed. RESULTS: The CpG dinucleotides surrounding promoter region of KIR3DL1 gene in NK-92MI cells were consistently methylated with a frequency of 70%-100%. After 72 h treatment with 2.5 mumol/L and 5 mumol/L of 5-azacytidine, the mRNA expression of KIR3DL1 gene in NK-92MI cells increased 66.6% and 114.6%, respectively. However, after 72 h treatment with 50 nmol/L of trichostatin A, the mRNA expression of KIR3DL1 gene in NK-92MI cells did not increase. Additionally, combined treatment with 5-azacytidine and trichostatin A did not lead to a synergistic effect compared with 5-azacytidine alone. CONCLUSION: KIR3DL1 expression in NK-92MI cells is regulated by promoter methylation.