title: Interleukin polymorphisms and differential methylation status in gastric cancer: an association with Helicobacter pylori infection.
abstract: OBJECTIVE
  Interleukin polymorphisms and Helicobacter pylori infection are believed to play critical roles in DNA methylation, a process frequently associated with carcinogenesis. The aim of this study was to determine the associations between interleukin polymorphisms and methylation status of three genes related to gastric cancer. Furthermore, the influence of the H. pylori strains was evaluated.
  
  
  METHODS
  75 gastric tumor samples had the DNA extracted for interleukin polymorphisms genotyping by PCR-RFLP, promoter methylation by MS-PCR and detection and subtyping of H. pylori by PCR.
  
  
  RESULTS
  In the cardia tumors, methylation in the COX-2 promoter was associated with IL1RN*2 (p = 0.015), and the associated genotypes IL1B511T + IL1RN*2 seem to be important in the methylation of COX-2 (p = 0.013), especially in the presence of cagA(+) (p = 0.026) and vacAs1 (p = 0.025) H. pylori strains. The associated genotypes IL6 CC+TNF GG seem to be involved in the unmethylation of CDKN2A (p = 0.046), along with H. pylori cagA(+) infection.
  
  
  CONCLUSIONS
  DNA methylation in gastric cancer seems to be influenced by the presence of interleukin polymorphisms and by the H. pylori cagA/vacAs1m1 strains.
authors.affiliation: Universidade Federal do Ceará, Department of Pathology & Forensic Medicine, Rua Alexandre Baraúna, 949, Porangabussu, CEP 60183-630, Fortaleza, Brazil. debora_mcosta@hotmail.com
authors.forename: Débora Menezes
authors.initials: DM
authors.lastname: da Costa
authors.forename: Eduardo Henrique Cunha
authors.initials: EH
authors.lastname: Neves-Filho
authors.forename: Markênia Kélia Santos
authors.initials: MK
authors.lastname: Alves
authors.forename: Silvia Helena Barem
authors.initials: SH
authors.lastname: Rabenhorst
mesh_terms: D000368:Aged; D001426:Bacterial Proteins / Q000235:genetics; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics*; D051546:Cyclooxygenase 2 / Q000235:genetics*; D019175:DNA Methylation / Q000235:genetics*; D044127:Epigenesis, Genetic / Q000235:genetics; D005260:Female; D056726:Genetic Association Studies; D016481:Helicobacter Infections / Q000150:complications / Q000235:genetics; D016480:Helicobacter pylori / Q000235:genetics / Q000472:pathogenicity; D006801:Humans; D015850:Interleukin-6 / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D013274:Stomach Neoplasms / Q000235:genetics* / Q000382:microbiology / Q000473:pathology
chemical_list: D001426:Bacterial Proteins; D019941:Cyclin-Dependent Kinase Inhibitor p16; C508600:IL6 protein, human; D015850:Interleukin-6; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human