Expression and methylation of DNA repair genes in lens epithelium cells of age-related cataract.

The development of age-related cataract (ARC) is associated with DNA damage of the lens epithelial cells (LECs). This study aimed to investigate the expression level of DNA repair genes in LECs of ARC and examine whether any altered expression observed could result from DNA methylation of the promoter region of the genes. The expression levels of DNA repair genes were evaluated by microarray analysis. The results were further confirmed by qRT-PCR. DNA methylation of genes with altered expression was determined by bisulfite-specific (BSP) PCR. The mRNA levels of 10 DNA repair genes were decreased and the level of 1 DNA repair gene was increased in LECs of ARC patients compared with controls. The promoter region of the MGMT gene was hypermethylated in ARC tissue compared to controls. The data provide evidence that altered expression of DNA repair genes is associated with pathogenesis of ARC. DNA methylation of MGMT may regulate the expression of the gene and be involved in the development of ARC.