Molecular characterization of feline COX-2 and expression in feline mammary carcinomas.
Cyclooxygenase-2 (COX-2), the rate-limiting enzyme in the biosynthesis of prostaglandins, plays an important role in inflammation and tumorigenesis. COX-2 primary structure has been characterized in many species and its expression demonstrated in a variety of cancers in humans and dogs, including mammary cancer. In contrast, there is currently little information on the structure of feline COX-2. Also, information on COX-2 expression in feline mammary cancer is limited and conflicting. The objectives of this study were therefore to characterize the molecular structure of feline COX-2 and to evaluate by immunohistochemistry its expression in mammary carcinomas. Our results show that the predicted coding region of feline COX-2 encodes a 604-amino acid protein, which is identical in length to several COX-2 homologs. Feline COX-2 amino acid sequence is highly similar to other mammalian COX-2 homologs. Immunohistochemical analysis of 40 mammary carcinomas showed that the majority of tumors studied (35/40; 87%) expressed COX-2 at a level varying from low (20/40; 50%) to intermediate (13/40; 32%) and high (2/40; 5%). These results provide the first molecular characterization of feline COX-2 and demonstrate that COX-2 is expressed in the majority of feline mammary carcinomas.
Sayasith
K
K
Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, 3200 Sicotte, Saint-Hyacinthe, Québec, J2S 7C6, Canada.
Sirois
J
J
Doré
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002371:Cat Diseases / Q000378:metabolism*; D002415:Cats; D051546:Cyclooxygenase 2 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology*; D015674:Mammary Neoplasms, Animal / Q000378:metabolism*; D008969:Molecular Sequence Data
D051546:Cyclooxygenase 2