Methylenetetrahydrofolate reductase 677 C→T polymorphism and risk of proximal colon cancer in North Italy

Abstract

Purpose: Gene silencing by hypermethylation plays an important role in proximal colon carcinogenesis. Conversely, DNA hypomethylation has been associated with distal colon cancer (CLC). Methylenetetrahydrofolate reductase (MTHFR) catalyzes the conversion of 5′,10′-methylenetetrahydrofolate to 5′-methyl tetrahydrofolate, which serves as methyl donor in the remethylation of homocysteine to methionine. A common MTHFR 677 C→T polymorphism is characterized by reduced catalytic activity, which affects methionine synthesis and DNA methylation. The aim of the study was to investigate the role of MTHFR 677 C→T gene polymorphism in the tumorigenesis of proximal and distal CLC in a monoinstitutional gr..