DAPK1, MGMT and RARB promoter methylation as biomarkers for high-grade cervical lesions

Gene promoter methylation may be used a potential biomarker for detecting solid tumor including cervical cancer. Here, we used methylation sensitive-high resolution melting (MS-HRM) analysis to detecting promoter methylation ratios of DAPK1, MGMT and RARB gene in patients with different cervical disease grade. The detection of gene promoter methylation was conducted in two hundred fifty patients' samples including normal cytology (n=48), cervical intraepithelial neoplasia grade 1 (CIN1, n=54), cervical intraepithelial neoplasia grade 2 (CIN2, n=47), cervical intraepithelial neoplasia grade 3 (CIN3, n=56) and cervical squamous cell carcinomas (SCS, n=45). We found there were a significant positive correlation between the promoter methylation status of DAPK1 and cervical disease grade (P=0.022). In addition, the methylated promoters of DAPK1 combined with MGMT, MGMT combined with RARB, DAPK1 combined with RARB were positive correlated with cervical disease grade (P < 0.05). All three genes promoters methylated were positive correlated with cervical disease grade (P < 0.001). Receiver operating characteristic (ROC) curves was conducted to evaluate whether the three genes methylation could be used to be a potential marker for diagnosing high grade cervical disease (HSIL and SCC). The cutoff values for the methylation rates of all these genes were 0-5%. Regrettably, only the methylation of MGMT combined with DAPK1 gave 43.4% sensitivity and 68.6% specificity. The current results indicated that MS-HRM-based testing for DNA methylations of MGMT plus DAPK1 genes holds some promise for high grade cervical disease screening.