[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 micromol/L and 5 micromol/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.