Characteristics of the Epithelial-Mesenchymal Transition in Primary and Paired Metastatic Canine Mammary Carcinomas

Made available in DSpace on 2018-12-11T17:20:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-09-01 The epithelial-mesenchymal transition (EMT) is a dynamic process linked to metastasis in many tumor types, including mammary tumors. In this study, we evaluated E-cadherin and vimentin immunolocalization in primary canine mammary carcinomas (20 cases) and their respective metastases, as well as their relationship with the core regulators SNAIL/SLUG. To assess the number of cells undergoing the process of EMT, we quantitated double-positive (E-cadherin+/vimentin+) cells using immunofluorescence, via cell counting and image analysis. In addition, SNAIL/SLUG expression was evaluated by established immunohistochemical methods. Primary tumors had significantly more E-cadherin+/vimentin+ co-expression than their paired respective lymph node or distant metastasis, respectively. Furthermore, the percentage of E-cadherin+/vimentin+ cells in grade II and III carcinomas was significantly higher than in grade I tumors. Primary tumors had significantly higher SNAIL/SLUG expression when analyzed based on the percentage of positive cells compared with their respective distant metastases in pairwise comparisons. An inverse correlation was noted between SNAIL/SLUG immunoreactivity and percentage of E-cadherin+/vimentin+ immunopositive cells in primary tumor samples when SNAIL/SLUG immunoreactivity was grouped into 2 categories (high versus low) based on percentage-positive staining. These results show a positive correlation between E-cadherin+/vimentin+ cells and higher tumor grade, establish differences between primary tumor and their respective metastases, and provide further support that EMT plays a critical role in the metastasis of canine mammary carcinoma. Furthermore, these data suggest that modulation of this process could provide greater therapeutic control and provide support for further research to determine if E-cadherin+/vimentin+ co-immunoreactivity imparts predictive value in the clinical outcome of patients with canine mammary carcinomas. Department of Veterinary Clinic and Surgery School of Agricultural and Veterinarian Sciences São Paulo State University (UNESP) Department of Clinical Sciences and Advanced Medicine School of Veterinary Medicine University of Pennsylvania Department of Pathobiology School of Veterinary Medicine University of Pennsylvania Penn Vet Cancer Center University of Pennsylvania Department of Veterinary Clinic School of Veterinary Medicine and Animal Science São Paulo State University (UNESP) Department of Companion Animal Clinical Sciences Faculty of Veterinary Medicine and Biosciences Norwegian University of Life Sciences Department of Biomedical Sciences School of Veterinary Medicine University of Pennsylvania Department of Veterinary Clinic and Surgery School of Agricultural and Veterinarian Sciences São Paulo State University (UNESP) Department of Veterinary Clinic School of Veterinary Medicine and Animal Science São Paulo State University (UNESP)