To investigate the role of Human MutL homologue 1 (hMLH1) gene promoter methylation in the occurrence and development of osteoarthritis (OA).
General DNA was dealt with sodium bisulfite. The methylation of hMLH1 promoter was detected by methylation-specific PCR (MSP). hMLH1 protein expression in joint cartilage was detected by immunohistochemical method.
The positive percent of hMLH1 promoter methylation in OA patients was higher than that in healthy persons (χ(2)=30.634, P<0.001); the positive percent of hMLH1 protein in OA patients was significantly lower than that in healthy persons (χ(2)=37.724, P<0.001); prmoter methylation and protein expression level of hMLH1 gene showed negative correlation (rs=-0.554, P<0.001).
hMLH1 promoter is hypermethlated in joint cartilage cells of OA patients. Hypermethylation may affect the protein expression of hMLH1, which might play a role in the occurrence and development of OA.