title: Oxidative stress-related enzyme gene polymorphisms and susceptibility to breast cancer in non-smoking, non-alcohol-consuming Taiwanese women: a case-control study.
abstract: BACKGROUND
  Mitochondrial manganese superoxide dismutase (MnSOD) converts superoxide anion into H(2)O(2), which is neutralized sequentially by either catalase (CAT) or glutathione peroxidase 1 (Gpx 1) into water or converted into highly reactive hypochlorous acid by myeloperoxidase (MPO). We hypothesize that gene variants for these enzymes might be associated with the risk of breast cancer in non-smoking, non-alcohol-consuming women.
  
  
  METHODS
  Genotypes of oxidative stress-related enzymes (MnSOD1183T>C, MPO-463G>A, GPx1Pro198Leu and CAT-262C>T) were analysed in 260 non-smoking and non-alcohol-consuming female patients with breast cancer and 224 habit-matched controls.
  
  
  RESULTS
  Subjects with the MnSOD1183T>C C carrier or those with the GPx1Pro198Leu CT genotype had significantly decreased age-adjusted risks (odds ratio [OR]: 0.56 and 0.16 with 95% confidence intervals [95% CI]: 0.38-0.83 and 0.08-0.29, respectively) for breast cancer. Certain combined genotypes of the polymorphisms also significantly modulated the age-adjusted risk.
  
  
  CONCLUSIONS
  We conclude that oxidative stress-related enzyme genetic variants, especially GPx1Pro198Leu CT, modify the risk of breast cancer development in non-smoking and non-alcohol-consuming women. The role of unidentified environmental factors predisposing to breast cancer development through an oxidative stress mechanism merits further investigation.
authors: Department of Public Health and Environmental Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors: Shih-Meng
authors: SM
authors: Tsai
authors: Szu-Hsien
authors: SH
authors: Wu
authors: Ming-Feng
authors: MF
authors: Hou
authors: Yueh-Ling
authors: YL
authors: Chen
authors: Hsu
authors: H
authors: Ma
authors: Li-Yu
authors: LY
authors: Tsai
mesh_terms: D001483:Base Sequence; D001943:Breast Neoplasms / Q000201:enzymology / Q000235:genetics*; D016022:Case-Control Studies; D017931:DNA Primers; D004843:Epistasis, Genetic; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D018384:Oxidative Stress; D011110:Polymorphism, Genetic; D060888:Real-Time Polymerase Chain Reaction; D013624:Taiwan
chemical_list: D017931:DNA Primers