Interaction of MTHFR polymorphism with PAX1 methylation in cervical cancer.

We aimed to investigate the roles and interaction effects of high-risk human papillomavirus (HR-HPV) infection, methyltetrahydrofolate reductase (MTHFR) polymorphism, and paired box gene 1 (PAX1) methylation in cervical intraepithelial neoplasia (CIN) and cervical cancer. Polymerase chain reaction was used to detect MTHFR polymorphism and PAX1 methylation; Mantel-Haenszel and Spearman's rank correlation tests were used to analyze the trends and correlations. Forty cases each of normal control (NC), CIN I, and CIN II/III and 9 squamous cell carcinoma (SCC) cases were enrolled. Increase in age increases the risk of cervical cancer. The HR-HPV infection rate, MTHFR mutation rate, and PAX1 methylation rate in CIN I, CIN II/III, and SCC groups were significantly higher than those in the NC group (P < 0.05). The above-mentioned rates gradually increased with the degree of cervical lesions. Moreover, HR-HPV infection, MTHFR polymorphism, and PAX1 methylation increased the risk of both CIN and cancer. A positive additive interaction was observed between PAX1 methylation and MTHFR polymorphism across different cervical lesion groups, whereas no interaction was found between HR-HPV infection and PAX1 methylation in lesion progression.