The Analysis Of Genome-Wide DNA Methylation Modifition In Breast Cancer

Breast cancer is one of common malignant tumor in women. The DNA methylation plays a very important role in breast cancer. The valuable information research of DNA methylation mechanism for breast cancer is significance for the clinical treatment of breast cancer. In order to study the difference of DNA methylation between the breast cancer cells and normal breast cell lines, DNA methylation in promoter regions, the first exon regions, exon regions and intron regions in the two cells are mainly studied in this paper. And the relationship between DNA methylation and gene expression are calculated. The change of DNA methylation in the cancer cells is found by comparing the cancer cells with normal breast cell lines, and the differentially methylated genes are analyzed by Gene Ontology (GO) and KEGG Pathway.The results shown that the levels of DNA methylation of four functional regions had taken place obvious changes in breast cancer cell lines. The Pearson correlation of DNA methylation levels and gene expression levels indicated that DNA methylation of the different functional regions have both positive control and negative control to gene expression. We found the molecular biology function of differentially methylated genes by GO analysis, and the target genes which are involved in pathways in cancer by KEGG Pathway. The DNA methylation profile of promoter regions of the target genes was analyzed for two normal human mammary epithelial cells and five human breast cancer cell lines. and we infered that abnormal methylation of some important genes may lead to the disorder of cells regulation mechanism and the occurrence of breast cancer. These results may be helpful for better understanding the pathogenesis of breast cancer.