title: Genetic polymorphisms of DNA double strand break gene Ku70 and gastric cancer in Taiwan.
abstract: OBJECTIVE
  The DNA repair gene Ku70, an important member of non-homologous end-joining repair system, is thought to play an important role in the repairing of DNA double strand breaks. It is known that defects in double strand break repair capacity can lead to irreversible genomic instability. However, the polymorphic variants of Ku70, have never been reported about their association with gastric cancer susceptibility.
  
  
  METHODS
  In this hospital-based case-control study, the associations of Ku70 promoter T-991C (rs5751129), promoter G-57C (rs2267437), promoter A-31G (rs132770), and intron 3 (rs132774) polymorphisms with gastric cancer risk in a Taiwanese population were investigated. In total, 136 patients with gastric cancer and 560 age- and gender-matched healthy controls recruited from the China Medical Hospital in Taiwan were genotyped.
  
  
  RESULTS
  As for Ku70 promoter T-991C, the ORs after adjusted by age and gender of the people carrying TC and CC genotypes were 2.41 (95% CI = 1.53-3.88) and 3.21 (95% CI = 0.96-9.41) respectively, compared to those carrying TT wild-type genotype. The P for trend was significant (P < 0.0001). In the dominant model (TC plus CC versus TT), the association between Ku70 promoter T-991C polymorphism and the risk for gastric cancer was also significant (adjusted OR = 2.48, 95% CI = 1.74-3.92). When stratified by age and gender, the association was restricted to those at the age of 55 or elder of age (TC vs TT: adjusted OR = 2.52, 95% CI = 1.37-4.68, P = 0.0139) and male (TC vs TT: adjusted OR = 2.58, 95% CI = 1.33-4.47, P = 0.0085). As for the other three polymorphisms, there was no difference between both groups in the distributions of their genotype frequencies.
  
  
  CONCLUSIONS
  In conclusion, the Ku70 promoter T-991C (rs5751129), but not the Ku70 promoter C-57G (rs2267437), promoter A-31G (rs132770) or intron 3 (rs132774), is associated with gastric cancer susceptibility. This polymorphism may be a novel useful marker for gastric carcinogenesis.
authors.affiliation: Terry Fox Cancer Research Lab, China Medical University Hospital, Taichung, Taiwan, R.O.C.
authors.forename: Mei-Due
authors.initials: MD
authors.lastname: Yang
authors.forename: Hwei-Chung
authors.initials: HC
authors.lastname: Wang
authors.forename: Wen-Shin
authors.initials: WS
authors.lastname: Chang
authors.forename: Chia-Wen
authors.initials: CW
authors.lastname: Tsai
authors.forename: Da-Tian
authors.initials: DT
authors.lastname: Bau
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D034961:Antigens, Nuclear / Q000235:genetics*; D053903:DNA Breaks, Double-Stranded; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005838:Genotype; D006801:Humans; D000072200:Ku Autoantigen; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012737:Sex Factors; D013274:Stomach Neoplasms / Q000235:genetics*; D013624:Taiwan
chemical_list: D034961:Antigens, Nuclear; D004268:DNA-Binding Proteins; C000606509:Xrcc6 protein, human; D000072200:Ku Autoantigen