[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 μmol/L and 5 μmol/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.