title: Methylenetetrahydrofolate reductase 677C/T gene polymorphism, gastric cancer susceptibility and genomic DNA hypomethylation in an at-risk Italian population.
abstract: We performed a case-control study to examine the relationship between MTHFR C677T gene polymorphism (MTHFR677C/T) and gastric cancer susceptibility in at-risk populations in central Italy. To explore genomic DNA hypomethylation as a potential etiologic mechanism, this phenomenon was evaluated in carriers of the MTHFR677T/T genotype and carriers of the wild-type MTHFR677C/C genotype. Lymphocyte genomic DNA from 162 gastric cancer patients and 164 controls was used for MTHFR677C/T genotyping. Unconditional regression analysis with ORs and 95% CIs was used to investigate the association of the polymorphism with disease. Genomic DNA methylation status by an established enzymatic assay that measures the DNA accepting capacity of methyl groups (inversely related to endogenous methylation) was assessed in a random sample of 40 carriers of the wild-type MTHFR677C/C genotype and 40 carriers of the MTHFR677T/T genotype. The global allelic distribution was in Hardy-Weinberg equilibrium. The MTHFR677T allele was significantly associated with gastric cancer risk with an OR of 2.49 (95% CI 1.48-4.20) in heterozygous MTHFR677C/T carriers and an OR of 2.85 (95% CI 1.52-5.35) in homozygous MTHFR677T/T carriers. This risk association was retained in subgroup analyses by tumor histotype and location. Genomic DNA hypomethylation status in MTHFR677T/T carriers was significantly higher than in subjects with wild-type MTHF677C/C genotype (p = 0.012). In the studied population, MTHFR677T played the role of a moderate-penetrance gastric cancer susceptibility allele. Possession of the MTHFR677T/T genotype was significantly associated with genomic DNA hypomethylation. These findings deserve further investigation in the context of novel strategies for gastric cancer prevention.
authors.affiliation: Department of Medical Oncology, Hospital of Urbino, Urbino, Italy. frada@tin.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Graziano
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Kawakami
authors.forename: Annamaria
authors.initials: A
authors.lastname: Ruzzo
authors.forename: Go
authors.initials: G
authors.lastname: Watanabe
authors.forename: Daniele
authors.initials: D
authors.lastname: Santini
authors.forename: Francesca
authors.initials: F
authors.lastname: Pizzagalli
authors.forename: Renato
authors.initials: R
authors.lastname: Bisonni
authors.forename: Davide
authors.initials: D
authors.lastname: Mari
authors.forename: Irene
authors.initials: I
authors.lastname: Floriani
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Catalano
authors.forename: Rosarita
authors.initials: R
authors.lastname: Silva
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tonini
authors.forename: Valter
authors.initials: V
authors.lastname: Torri
authors.forename: Lucio
authors.initials: L
authors.lastname: Giustini
authors.forename: Mauro
authors.initials: M
authors.lastname: Magnani
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000235:genetics*; D004198:Disease Susceptibility; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000201:enzymology / Q000453:epidemiology / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm; D042965:Methylenetetrahydrofolate Reductase (NADPH2)