Research On The Status Of HMLH1 Gene Promoter Methylation In Joint Cartilage Cells Of Osteoarthritis Patients

Objectives To investigate the role of Human mutL homologue 1 (hMLH1) gene promoter methylation in the occurrence and development of osteoarthritis (OA).Methods General DNA were dealed with Sodium Bisulfite method. The methylation of hMLH1 promoter was detected by Methylation-specific PCR (MSP). hMLH1 protein expression in joint cartilage cells were detected by Immunohistochemical method. 46 OA patients and 21 control patients were recruited from the in-patient of the second Xiangya hospital of Central South University.The results were analyzed by x~2 or Fisher's test and Spearman correlation analysis of SPSS17.0 statistic analysis software.Results1. The positive percent of hMLH1 promoter methylation in OA patients and healthy persons were 84.8% (39/46) and 14.3% (3/21) respectively, there was significantly different between the two groups(x~2=30.634,P=0.000).2. hMLH1 protein was expressed in joint cartilage cells of all 21 heathy persons. However,37 hMLH1 protein was not expressed in joint cartilage cells of 46 OA patients. Using x~2 test, the positive percent ofhMLH1 protein in OA patients was significantly lower than that in healthy persons(x~2=37.724, P =0.000).3. Prmoter methylation and protein expression level of hMLH1 gene showed significantly negative correlation.ConclusionshMLH1 promoter is hypermethlated in joint cartilage cells of OA patients. The hypermethylation affect the protein expression of hMLH1, which might take a role in the occurrence and development of OA .