ABSTRACT
Cyclooxygenase-2 (COX-2), P-glycoprotein (P-gp) and multi-drug resistance-associated protein (MRP) are considered important tumor-associated proteins in humans and dogs. In the present study, we immunohistochemically evaluated the expression of these proteins in canine patients with transitional cell carcinoma (TCC). Of 52 cases, 30 (57.7%) were positive for COX-2, 40 (76.9%) for P-gp, and only 10 (19.2%) for MRP. In addition, 27 samples (27/52, 51.9%) were positive for two markers, while 3 (5.7%) and 5 (9.6%) cases were positive and negative, respectively, for all three markers. No significant correlations were seen for COX-2 and P-gp on Fisher's exact test and Mann-Whitney's test, but a significance was seen on Spearman's rank correlation analysis using the IHC scoring system (P=0.043). These results suggest that P-gp expression is induced by overexpression of COX-2 in canine patients with TCC.
Subject(s)
ATP Binding Cassette Transporter, Subfamily B, Member 1/genetics , Carcinoma, Transitional Cell/veterinary , Cyclooxygenase 2/genetics , Dog Diseases/genetics , Gene Expression Regulation, Neoplastic , Multidrug Resistance-Associated Proteins/genetics , ATP Binding Cassette Transporter, Subfamily B, Member 1/metabolism , Animals , Carcinoma, Transitional Cell/genetics , Carcinoma, Transitional Cell/metabolism , Cyclooxygenase 2/metabolism , Dog Diseases/metabolism , Dogs , Drug Resistance, Neoplasm , Immunohistochemistry , Multidrug Resistance-Associated Proteins/metabolismABSTRACT
The expression of mRNA of the chemokine receptor CXCR4 in 65 surgically resected mammary adenocarcinomas from cats was investigated by in situ hybridisation. No expression of the receptor's mRNA was detectable in the mammary tissue of healthy cats, but it was expressed in areas adjacent to necrosis, surrounding blood vessels and cells infiltrating the lymphatics of 47 (72.3 per cent) of the 65 samples. There was a significant relationship between lymphatic infiltration by neoplastic cells and the expression of the receptor's mRNA (P < 0.005), but there was no significant relationship between its expression and the one-year survival of the cats.
