title: Alteration in Methylation Pattern of Retinoblastoma 1 Gene Promotor Region in Intestinal Metaplasia with or without Helicobacter pylori and Gastric Cancer Patients.
abstract: BACKGROUND
  Helicobacter pylori, intestinal metaplasia (IM), and gene methylation play important roles in gastric carcinogenesis. However, the association among H. pylori infection, IM, gastric cancer (GC), and gene methylation is not fully understood. Cell cycle control involving retinoblastoma 1 (RB1) gene is one of the main regulatory pathways reported to be altered in gastric carcinogenesis.
  
  
  OBJECTIVE
  The purpose of this research is to assess the methylation status of RB1 gene in GC and IM with or without H. pylori infection, and to discuss the possible role of H. pylori-induced RB1 gene methylation in the mechanism of gastric carcinogenesis.
  
  
  METHODS
  The methylation profile of RB1 gene was analyzed by sodium bisulfite modification and methylation-specific PCR in GC (n = 24), IM patients with H. pylori positive (n = 20) and negative (n = 20), and control subjects (n = 20).
  
  
  RESULTS
  According to methylation levels in RB1 gene; the high correlation values were detected between H. pylori positive-IM group and GC group, and between H. pylori positive-IM and H. pylori negative-IM groups (p < 0.05). No correlations between H. pylori negative-IM and GC groups and between GC and control groups were detected in methylation status of RB1 gene.
  
  
  CONCLUSIONS
  High methylation levels in RB1 gene in H. pylori positive individuals may suggest an elevated risk of gastric cancer occurrence.
authors.affiliation: Department of Medical Genetics, Faculty of Medicine, Adnan Menderes University, Aydin, Turkey.
authors.forename: Seda Orenay
authors.initials: SO
authors.lastname: Boyacioglu
authors.affiliation: Department of Gastroenterology, Faculty of Medicine, Celal Bayar University, Manisa, Turkey.
authors.forename: Elmas
authors.initials: E
authors.lastname: Kasap
authors.affiliation: Department of Gastroenterology, Faculty of Medicine, Celal Bayar University, Manisa, Turkey.
authors.forename: Hakan
authors.initials: H
authors.lastname: Yuceyar
authors.affiliation: Department of Medical Biology, Faculty of Medicine, Celal Bayar University, Manisa, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Korkmaz
mesh_terms: D000328:Adult; D000368:Aged; D019175:DNA Methylation; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000235:genetics* / Q000382:microbiology; D016480:Helicobacter pylori / Q000502:physiology; D054884:Host-Pathogen Interactions; D006801:Humans; D007422:Intestines / Q000382:microbiology / Q000473:pathology*; D008297:Male; D008679:Metaplasia / Q000150:complications / Q000235:genetics; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016160:Retinoblastoma Protein / Q000235:genetics*; D013274:Stomach Neoplasms / Q000150:complications / Q000235:genetics*
chemical_list: D016160:Retinoblastoma Protein
keywords: Helicobacter pylori; gastric cancer; intestinal metaplasia; methylation; retinoblastoma 1