Immunohistochemical Expression of Cyclooxygenase-2 in Normal, Hyperplastic and Neoplastic Canine Lymphoid Tissues

• Published in: Journal of comparative pathology Vol. 151; no. 1; pp. 35 - 41
• Main Authors: Asproni, P., Vignoli, M., Cancedda, S., Millanta, F., Terragni, R., Poli, A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.2014
• Subjects: Animals; COX-2; Cyclooxygenase 2 - biosynthesis; dog; Dog Diseases - metabolism; Dogs; Female; Hyperplasia - metabolism; Hyperplasia - veterinary; Immunohistochemistry; lymphoid tissue; Lymphoid Tissue - metabolism; lymphoma; Lymphoma - metabolism; Lymphoma - veterinary; Male; COX-2; lymphoid tissue; dog; lymphoma
• ISSN: 0021-9975; 1532-3129
• DOI: 10.1016/j.jcpa.2014.03.008

There is much interest in the potential use of selective inhibitors of cyclooxygenase (COX)-2 in combination with other cancer therapeutics. COX-2 is a key enzyme in prostaglandin synthesis and has been implicated in the pathogenesis of numerous canine and feline malignancies. There are few data on the potential role of COX-2 in the pathogenesis of canine lymphoma. The present study examined COX-2 expression in normal, hyperplastic and neoplastic canine lymphoid tissues. Immunohistochemical expression was evaluated in 12 samples of non-pathologically enlarged normal lymph nodes, 24 samples of hyperplastic lymph node and 44 samples of lymphoma (22 B-cell and 22 T-cell lymphomas). The labelling was scored semiquantitatively and a score of +2 or +3 was interpreted as overexpression. In hyperplastic lymph nodes only a few macrophages were COX-2-positive while six of the 44 lymphomas (13.6%; three B- and three T-cell lymphomas) overexpressed COX-2. These data provide a rationale for further investigation of COX-2 expression in canine lymphoma for prognostic, chemopreventive and chemotherapeutic purposes.