title: Genetic polymorphism of XRCC3 codon 241 and Helicobacter pylori infection-related gastric antrum adenocarcinoma in Guangxi Population, China: a hospital-based case-control study.
abstract: BACKGROUND
  The relationship between Helicobacter pylori infection and gastric antrum adenocarcinoma (GAA) has previously been demonstrated and supported with strong epidemiological evidence. However, the role of genetic polymorphism of X-ray cross-complementing group 3 (XRCC3) Thr241Met (rs#861539), which may be involved in the repair of DNA double-strand breaks caused by carcinogens such as CagA, a protein produced by H. pylori, has been less well elaborated.
  
  
  METHODS
  We conducted a hospital-based case-control study, including 721 patients with pathologically confirmed GAA and 989 individually matched controls without any evidence of tumors or precancerous lesions to evaluate the associations between this polymorphism and GAA risk in the Guangxi population. XRCC3 codon 241 genotypes and CagA status were determined using TaqMan-PCR and PCR, respectively.
  
  
  RESULTS
  Increased risks of GAA were found for cagA-positive individuals [odds ratio (OR), 7.31; 95% confidence interval (CI), 5.87-9.09]. We also found that individuals with the XRCC3 genotypes with codon 241 Met (namely XRCC3-TM or XRCC3-MM) had an increased risk of GAA compared with those with the homozygote of XRCC3 codon 241 Thr alleles (namely XRCC3-TT, adjusted ORs 1.76 and 3.73; 95% CIs 1.37-2.24 and 2.66-5.23, respectively). The risk of GAA, moreover, appeared to differ more significantly among individuals featuring cagA-positive status, whose adjusted ORs (95% CIs) were 11.31 (8.34-15.33) and 27.48 (15.17-49.78), respectively.
  
  
  CONCLUSIONS
  These results suggest that XRCC3 Thr241Met polymorphism may be associated with the risk of GAA related to CagA.
authors.affiliation: Department of Pathology, Shanghai Jiao Tong University School of Medicine, Shanghai, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Zhao
authors.forename: Xi-Dai
authors.initials: XD
authors.lastname: Long
authors.forename: Jin-Guang
authors.initials: JG
authors.lastname: Yao
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Yun
authors.initials: Y
authors.lastname: Ma
authors.forename: Yong-Zhi
authors.initials: YZ
authors.lastname: Huang
authors.forename: Yun-Qian
authors.initials: YQ
authors.lastname: Li
authors.forename: Min-Fa
authors.initials: MF
authors.lastname: Wang
authors.forename: Guo-Hui
authors.initials: GH
authors.lastname: Fu
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000382:microbiology; D000328:Adult; D000368:Aged; D000942:Antigens, Bacterial / Q000032:analysis / Q000235:genetics; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics; D016022:Case-Control Studies; D002681:China; D003062:Codon; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005838:Genotype; D016481:Helicobacter Infections / Q000150:complications / Q000235:genetics; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D011706:Pyloric Antrum / Q000382:microbiology / Q000473:pathology; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000235:genetics* / Q000382:microbiology
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D003062:Codon; D004268:DNA-Binding Proteins; C110901:X-ray repair cross complementing protein 3; C080866:cagA protein, Helicobacter pylori