Cloning of DNA methyltransferase 3A and 3B in Human Cancer

Abstract

DNA Methylation acts as an essential regulatory mechanism of transcription affecting chromatin structure, which is established and properly maintained by the co-ordinate action of three DNA methyltransferases: DNMT1, DNMT 3A and 3B and histone modifications.DNMT1 is constitutively expressed and is required for the maintenance of global methylation after DNA replication. In contrast, the DNMT3 family genes appear to be developmentally regulated and behave like de novo DNA methyltransferases in vitro . Recent
studies show that epigenetic change plays a major role in silencing a variety of methylated tissue-specific and imprints genes in many cancer types. The DNMT3A and DNMT3B show high homology in the carboxy terminal catalytic domain and contain a conserved cysteine rich region which allocate homology with the X-linked ATRX gene of the SNF2/SWI family.
In this study, we have cloned human DNMT3Aand DNMT3B. This cloning of the human DNMT3 genes will facilitate further biochemical and genetic studies of their functions in
establishment of DNA methylation patterns, regulation of gene expression and tumorigenesis.