Electrochemotherapy induces tumor regression and decreases the proliferative index in canine cutaneous squamous cell carcinoma.

Canine cutaneous squamous cell carcinoma (cSCC) is the most common skin cancer in dogs, and, due to its low metastatic rate, local treatments, such as electrochemotherapy (ECT), promote disease control or even complete remission (CR). This study aimed to evaluate the gene and protein expression of Bcl-2 and Bcl-2 associated X protein (BAX), the proliferative index and clinical parameters in dogs with cSCC subjected to ECT. A prospective nonrandomized clinical study was performed using dogs with naturally occurring cSCC that was treated with ECT. Eighteen lesions from 11 dogs were selected. The tumor size at day 0 (D0) had no impact on survival or prognosis (P > 0.05). Tumor samples had a lower proliferative index after ECT (D21) than before ECT (P = 0.031). The survival of subjects with Ki67 values lower and higher than the Ki67 median value were not significantly different (P > 0.05). Regarding apoptotic markers, there were no significant differences in the gene and protein expression levels of BAX or Bcl-2 at D0 and D21 (P > 0.05) or in the overall survival of subjects with different levels of apoptotic markers. In conclusion, there was no change in BAX or Bcl-2 gene and protein expression in response to ECT at the time points evaluated, but ECT was able to reduce tumor volume and cellular proliferation in cSCC.

Prognostic significance of Ki67 and its correlation with mitotic index in dogs with diffuse large B-cell lymphoma treated with 19-week CHOP-based protocol.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma in dogs. We evaluated Ki67 immunoexpression and mitotic index (MI) in dogs diagnosed with DLBCL and treated with a 19-wk CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) protocol. Twenty-nine lymph node samples from dogs diagnosed with DLBCL were analyzed for Ki67 immunostaining, and positive cells present in 1 cm2 were counted in a grid reticle for comparison of survival times above and below the means. The Ki67 mean was 107, and the MI mean was 21. There was a significant ( p < 0.05) difference in median survival time between Ki67 immunostaining above and below the mean, with no difference in MI groups. Ki67 values >107 positive cells per 5 HPF counted in a grid reticle were associated with shorter survival times in dogs with DLBCL treated with a 19-wk CHOP-based protocol.

Avaliação da imunomarcação de células-tronco tumorais em carcinossarcomas mamários e carcinomas em tumores mistos em cadelas / Evaluation of immunostaining of tumor stem cells in mammary carcinosarcomas and carcinomas in mixed tumors in bitches

As células-tronco tumorais (CTTs) pertencem a uma pequena população de células dentro do tumor com propriedades de autorrenovação e diferenciação em outros tipos celulares. Neste estudo avaliou-se o comportamento tanto das porções mesenquimais quanto das epiteliais de seis carcinossarcomas (CSs), 11 carcinomas em tumores mistos (CTMs) grau I, 11 grau II e 10 grau III. Nas porções epiteliais dos CS e CTM foram observadas imunomarcações para os anticorpos CD44, CD24, Oct-4 e ALDH-1. Nas porções mesenquimais dos CS, nas porções epiteliais dos CTMs graus II e III não houve imunomarcação para o ALDH-1. Concluiu-se que as CTTs são expressas em proporções iguais tanto nas porções mesenquimais quanto nas epiteliais dos CSs e ausentes nas porções mesenquimais bem diferenciadas de CTMs.

Cancer stem cells belong to a small population of cells within the tumor with properties of self-renewal and differentiation into other cell types. In this study, the behavior of both portions, mesenchymal and epithelial, was evaluated. Six carcinosarcomas (CSs), 11 carcinomas within mixed tumors (CWMTs) grade I, 11 grade II, and 10 grade III were evaluated. In the epithelial portions of the CS and CWMTs was observed immunostaining for antibodies CD44, CD24, Oct-4 and ALDH-1. In the mesenchymal portions of the CS, in the epithelial portions of CMTs grades II and III no immunostaining for ALDH-1 was found. It was concluded that the tumor stem cells are expressed in equal proportions in the epithelial and mesenchymal portions of the CS. No immunostaining in the mesenchymal portions of well-differentiated CWMTs was seen.