title: [Association between genetic polymorphisms in folate metabolic enzyme genes and colorectal cancer: a nested case-control study].
abstract: OBJECTIVE
  To investigate the interrelationship of genetic polymorphisms in folate metabolic enzymes (MTHFRC677T, MTHFRA1298C, MTRA2756G and MTRRA66G) and their combinative effects with colorectal cancer (CRC).
  
  
  METHODS
  A nested case-control study was designed and carried out. 140 CRC patients and 343 control subjects were included in this study. Polymorphisms of folate metabolic enzyme genes were genotyped by PCR-restriction fragment length polymorphism method. Risk of CRC was estimated by unconditional logistic model, and P value for interaction was calculated by likelihood test.
  
  
  RESULTS
  The allele of MTR2756G showed a positive association with CRC (OR = 2.04, 95% CI = 1.22 - 3.40). Those with MTHFR1298AA and MTR 2756AG/GG genotypes had an elevated risk with CRC (OR = 2.57, 95% CI, 1.42 -4.65), and their combinative effect showed a significant association with CRC (P = 0.04).
  
  
  CONCLUSIONS
  MTR2756G allele may be a risk factor of CRC, and interaction may exsit between polymorphisms of MTHFRA1298C and MTRA2756G. Further studies with larger sample and in different ethnic groups are needed.
authors.affiliation: School of Public Health, Zhejiang University, Hangzhou 310031, China. ck@zju.edu.cn
authors.forename: Kun
authors.initials: K
authors.lastname: Chen
authors.forename: Liang
authors.initials: L
authors.lastname: Song
authors.forename: Ming-Juan
authors.initials: MJ
authors.lastname: Jin
authors.forename: Chun-Hong
authors.initials: CH
authors.lastname: Fan
authors.forename: Qin-Ting
authors.initials: QT
authors.lastname: Jiang
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Yu
mesh_terms: D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase / Q000235:genetics*; D000483:Alleles; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000201:enzymology / Q000235:genetics*; D005260:Female; D005287:Ferredoxin-NADP Reductase / Q000235:genetics*; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length
chemical_list: C111241:methionine synthase reductase; D005287:Ferredoxin-NADP Reductase; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D013766:5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase