title: Analysis of cyclooxygenase expression in human colorectal adenomas.
abstract: BACKGROUND
  Evidence from rodent intestinal tumorigenesis models suggests that both cyclooxygenase-1 and cyclooxygenase-2 may play important roles in the development and progression of human sporadic colorectal adenomas. However, previous studies of cyclooxygenase isoform expression in human colorectal adenomas have produced conflicting data. Cyclooxygenase-1 expression has been poorly studied, and cyclooxygenase-2 positivity of adenomas has been variable depending on the detection technique used. It also remains unclear whether villous adenomas express cyclooxygenase-2.
  
  
  METHODS
  Cyclooxygenase isoform expression in human sporadic colorectal adenomas was analyzed by reverse transcription-polymerase chain reaction, Western blot analysis, and immunohistochemistry.
  
  
  RESULTS
  Variable cyclooxygenase-1 expression was detected in all adenomas (n = 9) by both reverse transcription-polymerase chain reaction and Western blot analysis. Cyclooxygenase-2 expression was detected in eight (89 percent) of nine adenomas by reverse transcription-polymerase chain reaction and immunohistochemistry. Cyclooxygenase-2 protein was not detected by Western blot analysis in any adenoma. Cyclooxygenase-2 was expressed by all histopathologic types of adenoma and localized predominantly to superficial interstitial cells, in which it was associated with increased adenoma size.
  
  
  CONCLUSIONS
  Cyclooxygenase-1 is expressed at variable levels by all adenomas. Cyclooxygenase-2 is expressed by the majority of adenomas, including those of the villous type, at levels below the sensitivity of Western blot analysis.
authors.affiliation: Academic Unit of Surgery, Department of Histopathology, University of Leeds, St. James's University Hospital, Leeds, United Kingdom.
authors.forename: Keith S
authors.initials: KS
authors.lastname: Chapple
authors.forename: Nigel
authors.initials: N
authors.lastname: Scott
authors.forename: Pierre J
authors.initials: PJ
authors.lastname: Guillou
authors.forename: P Louise
authors.initials: PL
authors.lastname: Coletta
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hull
mesh_terms: D000236:Adenoma / Q000201:enzymology*; D018253:Adenoma, Villous / Q000201:enzymology; D000328:Adult; D000368:Aged; D015153:Blotting, Western; D015179:Colorectal Neoplasms / Q000201:enzymology*; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D007527:Isoenzymes; D008565:Membrane Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases