title: Expression of cyclooxygenase-2 in canine epithelial nasal tumors.
abstract: Cyclooxygenase-2 (COX-2) is an enzyme upregulated in some human and animal tumors. Enzymatic products are associated with tumorigenic activities. Given the poor response of canine nasal tumors to radiation, we considered the possibility that some of this resistance may be associated with COX-2 expression. To test this, 21 formalin-fixed, paraffin-embedded, and archived biopsy samples from canine epithelial nasal tumors were analyzed for COX-2 expression using immunohistochemistry. The biopsies were collected from dogs prior to radiation therapy. COX-2 expression was present in 17 of 21 (81%) tumors. The expression was observed in several different tumor types, including nasal carcinomas, adenocarcinomas, and squamous cell carcinomas. Samples from five control dogs without nasal neoplasia were also analyzed for COX-2 staining. These specimens were characterized by varying degrees of lymphoplasmacytic rhinitis with scattered regions of COX-2 positive respiratory epithelial and stromal cells. Whether the intensity and distribution of COX-2 expression in nasal tumors can be used as a prognostic marker requires further investigation. A combination therapy of irradiation and a selective COX-2 inhibitor appears worthy of clinical investigation in the treatment of canine epithelial nasal tumors.
authors.affiliation: Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA. Miriam_Kleiter@ncsu.edu
authors.forename: Miriami
authors.initials: M
authors.lastname: Kleiter
authors.forename: David E
authors.initials: DE
authors.lastname: Malarkey
authors.forename: David E
authors.initials: DE
authors.lastname: Ruslander
authors.forename: Donald E
authors.initials: DE
authors.lastname: Thrall
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000662:veterinary; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000201:enzymology / Q000662:veterinary; D016022:Case-Control Studies; D003131:Combined Modality Therapy; D051546:Cyclooxygenase 2; D004283:Dog Diseases / Q000188:drug therapy / Q000201:enzymology* / Q000532:radiotherapy; D004285:Dogs; D015972:Gene Expression Regulation, Neoplastic; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D009669:Nose Neoplasms / Q000201:enzymology / Q000662:veterinary*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D011996:Records / Q000662:veterinary; D012189:Retrospective Studies
chemical_list: D007527:Isoenzymes; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases