High-resolution melting analysis of HPV-16 L1 gene methylation: A promising method for prognosing cervical cancer

Objective: Methylation-sensitive high-resolution melting (MS-HRM) is a new technique for DNA methylation analysis, but it is rarely used for the detection of viral DNA methylation. In this study, we investigated the HPV-16 L1 gene methylation that is detected by MS-HRM as a potential biomarker for prognosing cervical dysplasia and cancer. Design and methods: A total of 114 HPV-16 infected patients (normal (17), CIN1 (25), CIN2 (29), CIN3 (32), SCC (11)) who underwent liquid-based cytology test and biopsy were included in this study. 17 cases with HPV-16 infection and negative cytologic and histologic results served as the control group. The HPV-16 L1 gene methylation statuses of these samples were investigated using a methylation-sensitive high-resolution melting (MS-HRM) assay after bisulfite modification. Results: The HPV-16 L1 gene methylation statuses of all the 114 specimens were successfully detected by MS-HRM, and we observed increasing methylation levels in severe lesions, as determined using histologic assays. In addition, the methylation levels of CIN2 + (CIN2, CIN3 and SCC) were significantly higher than that of CIN2-(normal and CIN1, P <0.001). When taking CIN2 + as the reference, our HPV-16 L1 DNA methylation assay achieved 91.7% sensitivity and 59.5% specificity, respectively. Conclusions: The results of the present work demonstrated that HPV-16 L1 gene methylation was closely associated with cervical precancerosis and cancer. Moreover, using MS-HRM to detect HPV-16 L1 gene methylation may be a powerful assay for the triage of HPV-16-positive females, which could identify patients with high risk of invasive cancer. (C) 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.