DNA methylation regulates kir3dl1 gene expression in K562 cell line

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 de-methylation 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.