title: Analysis of promoter methylation, polymorphism and expression profile of cytotoxic T-lymphocyte-associated antigen-4 in patients with gastric cancer.
abstract: OBJECTIVE
  Cytotoxic T lymphocyte-associated antigen-4 (CTLA4) is a crucial immune-checkpoint receptor regulating T-cell activation. The current study was carried out to evaluate the function of CTLA4 gene in patients with gastric cancer.
  
  
  METHODS
  The methylation of CTLA4 gene promoter was evaluated by methylation-specific polymerase chain reaction (MSP) technique using 85 paraffin-embedded gastric cancer tissue samples and normal tissue on the tumor margins as control tissue samples. Expression analysis was performed on paraffin-embedded tissue samples (25 each of cancerous and normal tissues) using Real-time PCR.
  
  
  RESULTS
  Statistically significant differences were observed between the tumor and margin-cell areas with respect to promoter methylation status (OR = 4.829, 95% CI: 2.46-9.48, p < 0.001) and CTLA4 expression profile (mean +/- SD = 7.56 +/- 17.35, p = 0.04).
  
  
  CONCLUSIONS
  To the best of our knowledge, the current study is the first one highlighting the association between promoter hypermethylation of CTLA4 gene, decreased CTLA4 expression, and increased risk of gastric cancer.
authors.affiliation: Department of Biology, University of Sistan and Baluchestan, Zahedan, Iran. dor_kordi @science.usb.ac.ir; dor_kordi@yahoo.com.
authors.forename: Dor Mohammad
authors.initials: DM
authors.lastname: Kordi-Tamandani
authors.affiliation: Department of Biology, University of Sistan and Baluchestan, Zahedan, Iran.
authors.forename: Shahrbbanou Karimi
authors.initials: SK
authors.lastname: Davani
authors.affiliation: Department of Biology, University of Sistan and Baluchestan, Zahedan, Iran.
authors.forename: Taybeh
authors.initials: T
authors.lastname: Baranzehi
authors.affiliation: Department of Radiation Oncology, Isfahan University of Medical Science, Isfahan, Iran.
authors.forename: Simin
authors.initials: S
authors.lastname: Hemati
mesh_terms: D000328:Adult; D000368:Aged; D060908:CTLA-4 Antigen / Q000235:genetics*; D019175:DNA Methylation; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D016612:Paraffin Embedding; D010641:Phenotype; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic; D060888:Real-Time Polymerase Chain Reaction; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000235:genetics* / Q000276:immunology / Q000473:pathology / Q000601:surgery
chemical_list: D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human