title: Single nucleotide polymorphisms in the promoter region of the E-cadherin gene in gastric cancer: case-control study in a young Mexican population.
abstract: BACKGROUND
  Gastric cancer has a tendency to present at early age in the Mexican population, and it is frequently associated with a family history. A polymorphism at position -160 at the CDH1 promoter region has been reported to lead to transcriptional downregulation of the gene in vitro, with possible increase in the risk of gastric cancer. We evaluated the role of the -160A allele in the risk of gastric cancer in a young Mexican population.
  
  
  METHODS
  Peripheral blood sample of Mexican patients younger than 45 years old with diagnosis of diffuse gastric cancer were obtained. We performed DNA extraction and analyzed the frequencies of -160 promoter polymorphism of E-cadherin gene by polymerase chain reaction-single strand conformational polymorphism. These frequencies were compared with those of healthy controls. The chi2 test for association was used to test differences of the genotype frequencies between normal controls and patients with gastric cancer. Findings were considered significant at P < .05.
  
  
  RESULTS
  The frequency of the -160 A allele was significantly higher (P = .002) in 39 patients with diffuse gastric cancer compared with 78 matched controls. The odds ratio associated with the A-allele was 1.98 for C/A heterozygotes (95% CI 1.01-3.98) and 6.5 for A/A homozygotes (95% CI 2.1-19.6). We found an increased risk of diffuse gastric cancer according to family history, independent of the expression of the polymorphism.
  
  
  CONCLUSIONS
  The -160 C/A polymorphism of the E-cadherin has a direct effect on the risk of diffuse gastric cancer at young age in Mexican population.
authors.affiliation: Department of Surgery, Section of Surgical Oncology, National Institute of Medical Sciences and Nutrition Salvador Zubirán, Vasco de Quiroga 15, Colonia Seccion XVI, Tlalpan, Mexico City, Mexico. herimd@hotmail.com
authors.forename: Heriberto
authors.initials: H
authors.lastname: Medina-Franco
authors.forename: Antonio
authors.initials: A
authors.lastname: Ramos-De la Medina
authors.forename: Gloria
authors.initials: G
authors.lastname: Vizcaino
authors.forename: Jose Luis
authors.initials: JL
authors.lastname: Medina-Franco
mesh_terms: D000328:Adult; D000483:Alleles; D015820:Cadherins / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D008297:Male; D008800:Mexico / Q000453:epidemiology; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology
chemical_list: D015820:Cadherins