The effects of vincristine sulfate on expression of galectin-3, Bcl-2, and carbohydrate structures specific for EEL, GSL-1, and RCA-1 lectins in bitches with naturally occurring canine transmissible venereal tumor

Abstract

Vincristine sulfate is one of the most effective chemical agents used in canine transmissible venereal tumor (CTVT) chemotherapy. Its therapeutic effectiveness is pronounced and significant at the beginning of treatment. The present study was designed to investigate vincristine sulfate treatment and the relationship between CTVT tumor regression and apoptosis [estimated by TdT-mediated dUTP-biotin nick end labeling (TUNEL)], galectin-3 (H-160), Bcl-2 (N-9), and lectin [EEL (B-135), GSL I (L-1100), and RCA I (BA-0084)] expression using immunohistochemical staining in 20 bitches with naturally occurring CTVTs. Evaluation was semiquantitatively performed by HSCORE values using light microscopy All observed staining was intracytoplasmic and increased endothelial staining was noted with the Bcl-2 marker in tumor vessels. Apoptosis, TUNEL, and lectin scoring was higher in vincristine sulfate-treated tumors than in untreated tumors, while expression of antiapoptotic factors galectin-3 and Bcl-2 were lower in treated than in untreated CTVTs. These results show that galectin-3, Bcl-2, and lectins (EEL, GSL-1, and RCA-1) are suitable indicators/markers for CTVT tumor regression after treatment with vincristine sulfate.