title: COX-2 is expressed in human pulmonary, colonic, and mammary tumors.
abstract: BACKGROUND
  The cyclooxygenase (COX) enzyme catalyzes the formation of prostaglandins, which can affect cell proliferation and alter the response of the immune system to malignant cells. The inducible form of COX, COX-2, has been shown to be important in carcinogenesis.
  
  
  METHODS
  The authors studied COX-1 and -2 expression in 20 tumors of the lung, colon, and breast (60 total) by using commercially available monoclonal and polyclonal antibodies on formalin fixed, paraffin embedded tissue. Our evaluation also included seven carcinoma-associated colonic adenomas and 10 mammary ductal carcinomas in situ (DCIS). Quantitation of immunoreactivity was accomplished using an immunohistochemical scoring system that approximates the use of image analysis-based systems.
  
  
  RESULTS
  Ninety percent of lung tumors (squamous cell carcinomas and adenocarcinomas), 71% of colon adenocarcinomas and 56% of breast tumors (DCIS and infiltrating ductal and lobular carcinomas) expressed COX-2 at a moderate to strong level, which was significantly different from the negligible expression in distant nonneoplastic epithelium (controls; P < 0.0001). Poorly differentiated histologic features were correlated with low COX-2 expression overall, especially in colon carcinomas. Among breast carcinomas, DCIS was more likely to express COX-2 than invasive carcinomas. Adenomatous colonic epithelium showed moderate COX-2 expression, as did adjacent nonneoplastic epithelium. COX-1 immunoreactivity was essentially weak to moderate in all tissues evaluated.
  
  
  CONCLUSIONS
  COX-2 expression is upregulated in well and moderately differentiated carcinomas of the lung, colon, and breast whereas COX-1 appears to be constitutively expressed at low levels. A possible COX-2 paracrine effect is suggested by moderate immunoreactivity in adjacent nonneoplastic epithelium.
authors.affiliation: Department of Pathology, New York Presbyterian Hospital-Weill Medical College of Cornell University, New York, New York 10021, USA. soslowr@mskcc.org
authors.forename: R A
authors.initials: RA
authors.lastname: Soslow
authors.forename: A J
authors.initials: AJ
authors.lastname: Dannenberg
authors.forename: D
authors.initials: D
authors.lastname: Rush
authors.forename: B M
authors.initials: BM
authors.lastname: Woerner
authors.forename: K N
authors.initials: KN
authors.lastname: Khan
authors.forename: J
authors.initials: J
authors.lastname: Masferrer
authors.forename: A T
authors.initials: AT
authors.lastname: Koki
mesh_terms: D001940:Breast / Q000201:enzymology / Q000473:pathology; D001943:Breast Neoplasms / Q000201:enzymology / Q000473:pathology; D003106:Colon / Q000201:enzymology / Q000473:pathology; D003110:Colonic Neoplasms / Q000201:enzymology / Q000473:pathology; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis*; D008168:Lung / Q000201:enzymology / Q000473:pathology; D008175:Lung Neoplasms / Q000201:enzymology / Q000473:pathology; D008565:Membrane Proteins; D009369:Neoplasms / Q000201:enzymology / Q000473:pathology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis*
chemical_list: D007527:Isoenzymes; D008565:Membrane Proteins; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; C496511:PTGS1 protein, human; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases