Roles of histone acetylation in the Dnmt1 gene expression.

The DNA methylation plays a key role in the regulation of gene expression, genomic imprinting and X chromosome inactivation and has been shown to be essential for mammalian development. The Dnmt1 is one of the DNA methyltransferases that catalyzed DNA methylation on CpG dinucleotides. The Dnmt1 is constitutively expressed and is required for the maintenance of global methylation after DNA replication. In this study, we investigated the effects of histone deacetylase (HDAC) inhibitor and DNA demethylation agent on promoter activity of mouse Dnmt1 gene in somatic cells. The promoter activity of Dnmt1 gene was increased approximately 2-fold in the treatment of cells by Trichostatin A (TSA) at 1 x 10(-8) M, as compared with that without of treatment of TSA. By contrast, treatment with 5-azacytidine (5aza-C) did not affect the promoter activity of the Dnmt1 gene. These results indicate that the Dnmt1 gene is possibly to regulated by histone acetylation.