Expression of cyclooxygenase-2 in transitional cell carcinoma of the urinary bladder in dogs.
OBJECTIVE
To evaluate expression of cyclooxygenase (COX)-1 and COX-2 in the urinary bladder epithelium of clinically normal dogs and in transitional cell carcinoma cells of dogs.


METHODS
21 dogs with transitional cell carcinoma of the urinary bladder and 8 dogs with clinically normal urinary bladders.


METHODS
COX-1 and COX-2 were evaluated by use of isoform-specific antibodies with standard immunohistochemical methods.


RESULTS
COX-1, but not COX-2, was constitutively expressed in normal urinary bladder epithelium; however, COX-2 was expressed in neoplastic epithelium in primary tumors and in metastatic lesions of all 21 dogs and in new proliferating blood vessels in 3 dogs. Also, COX-1 was expressed in the neoplastic cells.


CONCLUSIONS
Lack of expression of COX-2 in normal bladder epithelium and its substantial expression in transitional cell carcinoma cells suggest that this isoform may be involved in tumor cell growth. Inhibition of COX-2 is a likely mechanism of the antineoplastic effects of non steroidal antiinflammatory drugs.
Khan
K N
KN
Searle Research and Development, Skokie, IL 60077, USA.
Knapp
D W
DW
Denicola
D B
DB
Harris
R K
RK
D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001706:Biopsy / Q000662:veterinary; D002295:Carcinoma, Transitional Cell / Q000201:enzymology / Q000473:pathology / Q000556:secondary / Q000662:veterinary*; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004195:Disease Models, Animal; D004283:Dog Diseases / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D004285:Dogs; D004848:Epithelium / Q000201:enzymology / Q000473:pathology; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D008175:Lung Neoplasms / Q000201:enzymology / Q000473:pathology / Q000556:secondary; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D001743:Urinary Bladder / Q000201:enzymology / Q000473:pathology; D001749:Urinary Bladder Neoplasms / Q000201:enzymology / Q000473:pathology / Q000662:veterinary*
D000894:Anti-Inflammatory Agents, Non-Steroidal; D052246:Cyclooxygenase 2 Inhibitors; D016861:Cyclooxygenase Inhibitors; D007527:Isoenzymes; D051545:Cyclooxygenase 1; D051546:Cyclooxygenase 2; D011451:Prostaglandin-Endoperoxide Synthases