Spontaneous canine transmissible venereal tumor: cell morphology and influence on P-glycoprotein expression

Abstract

The present study aimed to determine P-glycoprotein expression according to TVT cell morphology in 42 dogs with confirmed TVT, classified into lymphocytoid, plasmocytoid, and mixed. The chemotherapy efficiency was investigated along with its relation to P-glycoprotein expression in tumoral cells, evaluated by immunocytochemistry, considering positive tumors more than 10% stained. Among the samples collected, 50.00% possessed plasmocytoid morphology, 18.63% lymphocytoid, and 31.37% mixed. The plasmocytoid presented greater immunoreactivity to the anti-P-glycoprotein antibody in relation to the lymphocytoid. It was observed that the plasmocytoid was less sensitive to chemotherapy. The cases that had partial clinical response in the lymphocytoid were less compared with those in the plasmocytoid. Therefore, we can infer that the plasmocytoid presents a potential drug resistance. Based on this study, it can be concluded that the plasmocytoid presents a higher frequency of partial clinical response than the lymphocytoid and mixed, possibly through its higher percentage of anti-P-glycoprotein antibody expression.

Tumor venéreo transmissível (TVT) metastático em cadela: relato de caso

“…Diante dessas suspeitas, bem como por ser errante, optouse pela eutanásia da paciente. Metástases de TVT tendem a ocorrer principalmente em linfonodos, porém no sistema nervoso central (SNC), na glândula mamária e nos órgãos cavitários abdominais e torácicos, como pulmão, baço, útero e ovários (Pereira, Silva, Martins, Ferreira & Brooks, 2000;Bastan, Acar & Cengiz, 2008;Santos et al, 2012;Fonseca et al, 2014;Hendrick, 2017;Solano-Gallego & Masserdotti, 2023). Ainda, a ocorrência dessas precisa ser incluída em pacientes com massas genitais de TVT.…”

Canine Transmissible Venereal Tumor: An Infectious Neoplasia in Dogs

“…The researchers have revealed that the plasmacytic type is the most common cytomorphologic type [27,28]. The plasmacytic type [26][27][28][29][30] and the mixed type [26] are related to malignant behaviors and chemotherapeutic drug resistance. The…”

Canine transmissible venereal tumor – From general to molecular characteristics: A review

“…It is suggested that this cytomorphological type is associated with a higher degrees of DNA breaks and expression of P-glycoprotein, a transmembrane protein that acts on the efflux of chemotherapeutic drugs used in the treatment of CTVT, such as vincristine and doxorubicin. This fact would reduce the intracellular concentration of these, contributing to chemoresistance (Gaspar et al, 2009(Gaspar et al, , 2010. Thus, due to its prognostic value, the determination of cytomorphological classification has gained importance in veterinary clinical practice.…”