title: Expression of Cox-1 and Cox-2 in canine mammary tumours.
abstract: The aim of this study was to investigate immunohistochemically the expression of cyclooxygenase-1 (Cox-1) and cyclooxygenase-2 (Cox-2) in canine mammary tumours of different histological types. Cox-1 and Cox-2 enzyme expression was evaluated in 70 mammary samples (four normal, six hyperplastic, 60 neoplastic [21 benign and 39 malignant]). Cox-1 expression was identified in all the samples, and Cox-2 in all the mammary lesions except ductal hyperplasia. Two of the four normal mammary gland samples showed focal immunoreactivity for Cox-2. Cox-1 immunoexpression did not differ significantly between benign and malignant lesions (P=0.272). Cox-2 immunoexpression was higher in malignant tumours than in benign counterparts (P<0.001). Of the malignant tumours, carcinosarcomas and tubulopapillary and squamous cell carcinomas had the highest Cox-2 scores. The study showed that malignant tumours had the highest values of Cox-2 expression, and Cox-2 immunolabelling was particularly intense in histological types classically associated with high malignancy. This suggests that nonsteroidal anti-inflammatory drugs (NSAIDs), particularly Cox-2 inhibitors, may have a useful role to play in the treatment of canine malignant mammary tumours.
authors.affiliation: Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro, 5000-911, Vila Real, Portugal. fqueirog@utad.pt
authors.forename: F L
authors.initials: FL
authors.lastname: Queiroga
authors.forename: A
authors.initials: A
authors.lastname: Alves
authors.forename: I
authors.initials: I
authors.lastname: Pires
authors.forename: C
authors.initials: C
authors.lastname: Lopes
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000473:pathology / Q000662:veterinary*; D000236:Adenoma / Q000201:enzymology / Q000473:pathology / Q000662:veterinary*; D000818:Animals; D002296:Carcinosarcoma / Q000201:enzymology / Q000473:pathology / Q000662:veterinary*; D051545:Cyclooxygenase 1 / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D004283:Dog Diseases / Q000201:enzymology* / Q000473:pathology; D004285:Dogs; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D007124:Immunoenzyme Techniques / Q000662:veterinary; D008321:Mammary Glands, Animal / Q000201:enzymology / Q000473:pathology; D015674:Mammary Neoplasms, Animal / Q000201:enzymology* / Q000473:pathology
chemical_list: D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2