Correlation Research Between Methylation Of Mitochondrial Genes And Regulation Of Expression In Colorectal Cancer Cells

The CpG island methylation of DNA in epigenetics is a hot issue,cancer is closely related to gene methylation in the genome.The ATP of mitochondrial oxidative phosphorylation product is the main energy source of life activities,mitochondrial dysfunction leads to diseases such as neurodegenerative diseases and cancer.Mitochondrial DNA aberrant methylation can induce tumors,which can be used as a marker for tumor diagnosis,but mitochondrial gene methylation is little research that is associated with colorectal cancer.In this study,with colorectal cancer tissues and pra-cancer tissues,as well as the normal intestinal epithelial cell line FHC and colorectal cancer cell lines HCT116 as research materials,first by bisulfite modification combined with sequencing methods,the detection of methylation status and methylation level of several key genes of mitochondrial coding is find that the cancer tissue is higher than the pra-cancer tissue;The detection results of the cell lines were consistent with tissue material,that is,the level of methylation of CpG islands in the mitochondrial gene body regions of hctl 16 cells was higher than that of the FHC.In order to detect the level of mitochondrial gene methylation and the expression of the corresponding mitochondrial gene,and the correlation of cell proliferation,we treated the two cells with different concentration(0,0.5,1.0,1.5,2.0,2.5 um)drug of demethylation 5-Aza-dC,detection of the mitochondrial protein level and cell proliferation activity changes.The results of western blot showed that 5-Aza-dC after processing,the expression of MT-CO1,MT-CO2,MT-ND1,MT-ND3,VDAC protein expression decreased in hctl 16 cells,and the level of ATP decreased,the growth of cells was significantly inhibited;The FHC cells due to the low level of mitochondrial gene methylation,demethylation treatment has no significant effect on the mitochondrial protein,ATP content and cell proliferation.The above experimental results show that the decrease of methylation level of mitochondrial gene body regions can reduce the expression of the corresponding mitochondrial oxidative phosphorylation compound protein subunits,thereby reducing the mitochondrial ATP levels,and ultimately inhibit the expression of cells.This study helps us to understand more clearly the methylation level of different loci in colorectal cancer cells mitochondrial genes,and confirms that by helping to regulate mitochondrial methylation level can inhibit the proliferation of colorectal cancer cells,which provides a new train of thought for the early diagnosis and treatment of colorectal cancer.