title: Helicobacter pylori infection in relation to E-cadherin gene promoter polymorphism and hypermethylation in sporadic gastric carcinomas.
abstract: OBJECTIVE
  To study Helicobacter pylori (H. pylori) infection in relation to E-cadherin (E-cad) promoter polymorphism and hypermethylation in GCs.
  
  
  METHODS
  Specimens were taken from representative cancerous lesions and adjacent non-cancerous epithelia of 67 resected GCs. H. pylori was detected by real-time PCR of the cagA gene from non-neoplastic epithelium. E-cad promoter polymorphism and hypermethylation were determined by restriction fragment length polymorphism analysis and methylation-specific PCR, respectively. Expression of E-cad protein was determined by immunohistochemistry.
  
  
  RESULTS
  H. pylori was found in 57% of patients with GC. H. pylori infection was more frequently found in tumors with the -160C/C genotype than those with the -160C/A and -160A/A genotypes (74% vs 47%, P = 0.02). H. pylori infection was associated with E-cad methylation in non-neoplastic epithelium; however, no significant difference in H. pylori was observed between methylated and unmethylated cancerous lesions.
  
  
  CONCLUSIONS
  Patients with the -160C/C genotype might require H. pylori infection to promote the inactivation of CDH1, suggesting that H. pylori infection might affect GC in an initial stage because polymorphism is germ line. Mechanism of hypermethylation of CDH1 promoter in GC is complex, and H. pylori infection might affect it in an initial stage.
authors.affiliation: Division of General Surgery, Tri-Service General Hospital, No. 325, Sec. 2, Cheng-Kung Road, Neihu 114, Taipei, Taiwan, China. dlyaochi@yahoo.com.tw
authors.forename: Yao-Chi
authors.initials: YC
authors.lastname: Liu
authors.forename: Chen-Yang
authors.initials: CY
authors.lastname: Shen
authors.forename: Hurng-Sheng
authors.initials: HS
authors.lastname: Wu
authors.forename: De-Chuan
authors.initials: DC
authors.lastname: Chan
authors.forename: Cheng-Jueng
authors.initials: CJ
authors.lastname: Chen
authors.forename: Jyh-Cherng
authors.initials: JC
authors.lastname: Yu
authors.forename: Cheng-Ping
authors.initials: CP
authors.lastname: Yu
authors.forename: Horng-Jyh
authors.initials: HJ
authors.lastname: Harn
authors.forename: Rong-Yaun
authors.initials: RY
authors.lastname: Shyu
authors.forename: Yu-Lueng
authors.initials: YL
authors.lastname: Shih
authors.forename: Chung-Bao
authors.initials: CB
authors.lastname: Hsieh
authors.forename: Huan-Mieng
authors.initials: HM
authors.lastname: Hsu
mesh_terms: D015820:Cadherins / Q000235:genetics*; D002277:Carcinoma / Q000150:complications*; D019175:DNA Methylation; D016481:Helicobacter Infections / Q000150:complications*; D016480:Helicobacter pylori; D006801:Humans; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D013274:Stomach Neoplasms / Q000150:complications*
chemical_list: D015820:Cadherins