Study on DNA Methylation Status of WT1 Gene in Its Promoter Region in Hematologic Neoplasm Cell Lines.

The methylation at CpG island in the promoter region of a gene is one of the important epigenetic mechanism which regulates the gene activity. To study the DNA methylation pattern of WT1 gene promoter region within hematologic neoplastic cell lines and its correlation with WT1 gene expression by using the PCR-based methods. RT-PCR and Methylation-specific PCR were performed to study the WT1 gene expression in 8226, HL-60, Jurkat, K562, KG-1, NB4, Raji, SHI-1, U266 and U937 cell lines and the DNA methylation status in promoter region of WT1 gene. After treatment of U937 cell line by 5-aza-CdR, a demethylation inducing agent, the changes of WT1 gene expression level and the methylation status in its promter region in U937 cells was determined. Our Results showed that HL-60, K562, KG-1, NB4, SHI-1 cell lines demonstrated higher level of WT1 expression, while extremely low level was found in 8226, Jurkat, Raji, U266 and U937. The DNA hypermethylation in WT1 gene promoter region was identified in 8226, Jurkat, Raji, U266 and U937 cell lines. The WT1 gene expression in U937 was markedly enhanced after treatment with 5-aza-CdR in company with the decrease of methylated level and the increase of unmethylated level in its promoter region. These results indicate that modulation of the DNA methylation in WT1 promoter region is one of the epigenetic mechanisms to regulate its expression.