title: Characterization of Gastric Cardia Tumors: Differences in Helicobacter pylori Strains and Genetic Polymorphisms.
abstract: BACKGROUND
  Gastric cancer results from a multifactorial process and is one of the most common causes of death worldwide. These tumors can arise in the distal stomach (non-cardia) and in the cardia region, presenting different characteristics and frequency of occurrence worldwide.
  
  
  OBJECTIVE
  To search for differences between tumors of different locations that could explain the presence of cardia tumors, considering Helicobacter pylori strains and genetic polymorphisms.
  
  
  METHODS
  DNA was extracted from gastric adenocarcinoma tissue of 127 patients. Helicobacter pylori genes were detected by PCR, and polymorphisms by PCR-RFLP.
  
  
  RESULTS
  Most of the tumors were located in non-cardia. The genotype 28152GA of XRCC1 showed an increase in risk of cardia tumors. In analysis performed considering gender, women carrying TNF-308GA genotype showed a decreased risk of non-cardia tumors, while in men the decreased risk of non-cardia tumors was associated with TNF-308GG genotype. Genotypes combinations showed that the SNPs RAD51 135G>C, XRCC3 18067C>T, and XRCC1 28152G>A had some combinations more frequent in cardia tumors, with an increased risk. Patients infected by cagE-positive strains presented a positive correlation with non-cardia tumors.
  
  
  CONCLUSIONS
  The results showed some susceptibility differences between tumors of different locations. There was an increased risk relationship between three repair enzyme SNPs and cardia tumors, and the G allele of the cytokine gene TNF negatively influenced the development of non-cardia tumors. Helicobacter pylori strains seemed to be different in the cardia region, where they were less virulent than those located in the distal region of the stomach.
authors.affiliation: Molecular Genetics Laboratory, Department of Pathology and Forensic Medicine, School of Medicine, Federal University of Ceará, Street Coronel Nunes de Melo, 1315 - Rodolfo Teófilo, Fortaleza, Ceará, 60430-270, Brazil, debora_mcosta@hotmail.com.
authors.forename: Débora Menezes
authors.initials: DM
authors.lastname: da Costa
authors.forename: Eliane
authors.initials: E
authors.lastname: Dos Santos Pereira
authors.forename: Isabelle Joyce
authors.initials: IJ
authors.lastname: de Lima Silva-Fernandes
authors.forename: Márcia Valéria Pitombeira
authors.initials: MV
authors.lastname: Ferreira
authors.forename: Silvia Helena Barem
authors.initials: SH
authors.lastname: Rabenhorst
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000382:microbiology* / Q000473:pathology; D000942:Antigens, Bacterial / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D002299:Cardia; D004268:DNA-Binding Proteins / Q000235:genetics; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics; D005838:Genotype; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012150:Polymorphism, Restriction Fragment Length; D051135:Rad51 Recombinase / Q000235:genetics; D012737:Sex Factors; D013274:Stomach Neoplasms / Q000235:genetics* / Q000382:microbiology* / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C103937:PicB protein, Helicobacter pylori; D014409:Tumor Necrosis Factor-alpha; C074689:VacA protein, Helicobacter pylori; D000076105:X-ray Repair Cross Complementing Protein 1; C110901:X-ray repair cross complementing protein 3; C000619371:XRCC1 protein, human; C080866:cagA protein, Helicobacter pylori; C495153:RAD51 protein, human; D051135:Rad51 Recombinase