title: Cyclooxygenase-2 expression in equine tumors.
abstract: The enzyme cyclooxygenase-2 (COX-2) is expressed in some tumor and stromal tissues, and catalyzes production of prostaglandins with growth stimulatory, antiapoptotic, proangiogenic, and immunosuppressive properties. Pharmacologic inhibition of COX-2 is associated with antitumor activity in various human and canine malignancies. The purpose of this study was to assess COX-2 expression in a series of equine sarcoids, melanomas, and squamous-cell carcinomas (SCC). COX-2 expression was assessed in formalin-fixed paraffin-embedded tissues from 14 sarcoids, 11 melanomas, and 37 SCC that represent various anatomic sites by using standard immunohistochemical methods. COX-2 was expressed in 2 of 14 sarcoids, 7 of 11 melanomas, and 32 of 37 SCC, 56% of which demonstrated moderate-to-strong immunoreactivity. There were no differences in expression between anatomic sites. In conclusion, most equine SCC and many melanomas appear to express COX-2 and thus could respond to COX-2 inhibitor therapy.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523-1620, USA. dthamm@colostate.edu
authors.forename: D H
authors.initials: DH
authors.lastname: Thamm
authors.forename: E J
authors.initials: EJ
authors.lastname: Ehrhart
authors.forename: J B
authors.initials: JB
authors.lastname: Charles
authors.forename: Y A
authors.initials: YA
authors.lastname: Elce
mesh_terms: D000818:Animals; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006734:Horse Diseases / Q000201:enzymology*; D006736:Horses; D009369:Neoplasms / Q000201:enzymology / Q000662:veterinary*
chemical_list: D051546:Cyclooxygenase 2