Dados do Resumo

Título

FOXC1 AND FOXP3 EXPRESSION IN CANINE MAMMARY CARCINOMAS COMPARED TO BREAST CANCER IN WOMEN: PRELIMINARY ANALYSIS.

Introdução

Breast cancer is frequent in women and bitches. Due to species similarity, the dog poses as an alternative pre-clinical model to comparative research in human breast cancer. FOXC1 is a critical transcriptional regulator which, when overexpressed, is implicated in tumor progression in breast cancer in women, but no record was found in canine mammary cancer literature. FOXP3 is the main transcriptional factor and plays a role in cellular proliferation and differentiation.

Objetivo

To preliminarily evaluate FOXC1 and FOXP3 immunohistochemical expression in mammary carcinomas from bitches, comparing obtained results with those reported from human breast cancer, in order to evaluate the dog as a spontaneous animal model of this type of mammary cancer in women.

Métodos

UFF Ethics Committee in Animal Use approval n. 4260161119 and 1561300524. Five samples from canine mammary nodules were routinely processed, histopathologically evaluated, diagnosed as carcinoma and archived in UFF Veterinary Pathological Anatomy Laboratory. Satellite lymph node was evaluated for metastasis. Immunohistochemical evaluation was performed by streptavidin-biotin-peroxidase technique, using anti-FOXC1 primary antibody (rabbit monoclonal, 1:1000 dilution) and anti-FOXP3 primary antibody (rabbit polyclonal, 1:200 dilution). Revelation system employed secondary antibody Envision Dual link-HRP (Dako), diaminebenzidine as chromogen and Harris hematoxylin counterstaining. FOXC1 expression was considered positive if any brown nuclear immunostaining was observed in tumoral cells. FOXP3 expression was considered positive when at least 25% of tumoral cells area was immunostained, whether of weak or strong intensity. Results were evaluated by descriptive statistics tools.

Resultados

From five analyzed samples, four (80%, 4/5) presented metastasis foci in regional lymph node. FOXP3 immunohistochemical expression was observed in epitelial and mioepithelial cells from all five evaluated mammary carcinomas from bitches. Tumoral cells presented cytoplasmic immunostaining (100%; 5/5), of strong (60%; 3/5) and weak (40%; 2/5) intensity. As for FOXC1 immunostaining, well-defined nuclear immunomarking was observed in neoplastic cells from all five evaluated samples.

Conclusões

FOXP3 and FOXC1 are proteins that, when overexpressed in human mammary cancer, are related to cellular proliferation, aggressive biological behavior and poor prognosis. In this preliminary study, it was possible to identify positive FOXC1 and FOXP3 expression in these canine samples, demonstrating similarities between canine and human mammary carcinomas. More studies are required to fully understand FOXC1 and FOXP3 expression in canine mammary cancer and its potential as animal model.

Financiador do resumo

This study was funded/financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES)—Finance Code 001 and FAPERJ—Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro.

Palavras Chave

biomarkers; IMMUNOHISTOCHEMISTRY; mammary tumor