title: Genetic polymorphisms of methylenetetrahydrofolate reductase and aldehyde dehydrogenase 2, alcohol use and risk of colorectal adenomas: Self-Defense Forces Health Study.
abstract: Methylenetetrahydrofolate reductase is a key enzyme in folate metabolism, which affects DNA synthesis and methylation and is possibly linked to colorectal carcinogenesis. Alcohol and acetaldehyde have an adverse effect on folate metabolism. This study investigated the relationship of functional MTHFR C677T and ALDH2 polymorphisms to colorectal adenomas with reference to alcohol consumption in a case-control study of male officials in the Self-Defense Forces (SDF) who received a preretirement health examination at two SDF hospitals. The study subjects were 452 cases of colorectal adenoma and 1050 controls with no polyp who underwent total colonoscopy. Genotypes were determined by the PCR-RFLP method using genomic DNA extracted from the buffy coat. Statistical adjustment was made for age, hospital, rank in the SDF, body mass index, cigarette-years and alcohol intake. Neither MTHFR C677T nor ALDH2 showed a measurable association with colorectal adenoma. While high alcohol consumption was associated with a moderately increased risk of colorectal adenoma, neither of the two polymorphisms showed a significant effect on the association between alcohol and colorectal adenoma. Individuals with the variant alleles ALDH2*2 and MTHFR 677T had a decreased risk of colorectal adenomas, showing adjusted odds ratios of 0.70 (95% confidence interval 0.49-1.00) for all adenomas and 0.57 (0.34-0.95) for large adenomas (> or = 5 mm), as compared to individuals with ALDH2*1/1 and MTHFR 677CC genotypes combined. The findings may be interpreted as suggesting that folate inhibits the growth of colorectal adenomas, but further confirmation is needed.
authors.affiliation: Department of Preventive Medicine, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Maho
authors.initials: M
authors.lastname: Hirose
authors.forename: Suminori
authors.initials: S
authors.lastname: Kono
authors.forename: Shinji
authors.initials: S
authors.lastname: Tabata
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Ogawa
authors.forename: Keizo
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Masamichi
authors.initials: M
authors.lastname: Mineshita
authors.forename: Tomoko
authors.initials: T
authors.lastname: Hagiwara
authors.forename: Guang
authors.initials: G
authors.lastname: Yin
authors.forename: Kyong-Yeon
authors.initials: KY
authors.lastname: Lee
authors.forename: Akiko
authors.initials: A
authors.lastname: Tsuji
authors.forename: Noriaki
authors.initials: N
authors.lastname: Ikeda
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000235:genetics*; D000428:Alcohol Drinking; D000444:Aldehyde Dehydrogenase / Q000235:genetics*; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000235:genetics*; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007564:Japan; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008889:Military Personnel; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors
chemical_list: C096127:ALDH2 protein, human; D000444:Aldehyde Dehydrogenase; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D042965:Methylenetetrahydrofolate Reductase (NADPH2)