title: [Quantification of cyclooxygenase-2 methylation in gastric mucosa by denaturing high performance liquid chromatography assay].
abstract: OBJECTIVE
  To setup a quantitative assay for detection of cyclooxygenase-2 (COX-2) methylation in human gastric mucosa samples.
  
  
  METHODS
  A standard analysis system was established by denaturing high performance liquid chromatography (DHPLC) under the condition of 55 degrees C oven temperature and a linear acetonitrile gradient (4.0/min). While, a total of 10 cases of gastric biopsy samples were detected for methylation status of COX-2.
  
  
  RESULTS
  The complete methylated human promyelocytic leukemia cells (HL-60) and unmethylated gastric cancer cell line (MGC803) were used as positive and negative control. The proportion of the methylated copies of COX-2 was calculated according to the peak heights of methylated (M) and unmethylated (U) COX-2 in same PCR amplicon. The formula was Y = 1.0608 x M/(M + U), R(2) = 0.9894. Among 10 biopsy samples, the proportions of methylated copies of COX-2 in 2 cases of dysplasia were higher than superficial gastritis and chronic atrophy gastritis (24.5%, 18.4% vs 7.6%, 9.6%).
  
  
  CONCLUSIONS
  The methylation of COX-2 promoter CpG islands can be detected in human gastric mucosa samples by quantitative DHPLC assay, which could be used in the population-based study of precancerous gastric lesions.
authors.affiliation: Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Peking University School of Oncology, Beijing Cancer Hospital & Institute, Beijing 100142, China.
authors.forename: Xiao-Rui
authors.initials: XR
authors.lastname: Nie
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhang
authors.forename: Kai-Feng
authors.initials: KF
authors.lastname: Pan
authors.forename: Wen-Qing
authors.initials: WQ
authors.lastname: Li
authors.forename: Wei-Cheng
authors.initials: WC
authors.lastname: You
authors.forename: Lian
authors.initials: L
authors.lastname: Zhang
mesh_terms: D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D018899:CpG Islands; D051546:Cyclooxygenase 2 / Q000235:genetics*; D019175:DNA Methylation; D005753:Gastric Mucosa / Q000378:metabolism / Q000473:pathology; D006801:Humans; D011401:Promoter Regions, Genetic; D013272:Stomach Diseases / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: D051546:Cyclooxygenase 2