Aberrant DNA methylation of p16, MGMT, and hMLH1 genes in combination with MTHFR C677T genetic polymorphism and folate intake in esophageal squamous cell carcinoma

Abstract

Aim: The present case-control study was conducted to explore the association of MTHFR gene polymorphism and relations of P16, MGMT and HMLH1 to MTHFR and folate intake. Methods: A total of 257 cases of esophageal squamous cell carcinoma confirmed by histopathologicalexamination were collected. Genotyping of P16, MGMT and HMLH1 was accomplished by methylation-specific polymerase chain reaction (PCR) after sodium bisulfate modification ofDNA and the MTHFR C677T genetic polymorphism was detected by PCRrestriction fragment-length polymorphism (PCR-RFLP). Results: The proportions of DNA hypermethylation in P16, MGMTandhMLH1 in cancer tissues were significantly higher than in paracancerous normal tissue.The proportion of hypermethylation in at least one gene was 88.5% in cancer tissue, and wasalso significantly higher than that in paracancerous normal tissue. Our finding showed individuals with homozygotes (TT) of MTHFR C677T had significant risk of DNA hypermethylation of MGMT in cancer tissues, with an OR (95% CI) of 3.15 (1.12-6.87). Similarly, patients with high intake of folate also showed a slight high risk of DNA methylation of MGMT,with OR (95% CI) of 2.03 (1.05-4.57). Conclusion: Our study found the P16, MGMT and hMLH1demonstrate a high proportion of hypermethylation in esophageal squamous cell cancer cancer tissues, which might be used as biomarkers for cancer detection. © The Korean Pain Society, 2012.