TITLE:
Snai-1 and Epithelial-Mesenchymal Transition-Related Protein Immunoexpression in Canine Mammary Carcinomas
AUTHORS:
Breno S. Salgado, Rafael M. Rocha, Fernando A. Soares, Fátima Gärtner, Noeme S. Rocha
KEYWORDS:
EMT, S100A4, Keratin, Mammary Tumors, Dog
JOURNAL NAME:
Advances in Breast Cancer Research,
Vol.3 No.4,
October
22,
2014
ABSTRACT: Epithelial-mesenchymal transition (EMT) is defined as
switching of polarized epithelial cells to a migratory fibroblastoid phenotype.
EMT is known to be involved in the progression and metastasis of various
cancers in humans, but this specific process is still little explored in the
veterinary literature. The aim of this research was to evaluate the expression
of EMT-related proteins in canine mammary carcinomas (CMCs). The expression of
six EMT-related proteins in 94 CMCs of female dogs was evaluated by
immunohistochemistry using a tissue array method. Additionally,
clinicopathological characteristics were compared with the expression of
EMT-related proteins. Loss of epithelial protein and/or acquisition of the
expression of mesenchymal proteins were observed in CMCs. Loss of epithelial
protein and/or acquisition of the expression of mesenchymal proteins were
observed, particularly in tumors with evidence of stromal invasion; however,
significance was only observed between the S100A4 and vascular invasion. In
addition, Snai-1 nuclear immunoexpression was significantly related to
E-cadherin loss. In conclusion, loss of epithelial proteins and/or the
acquisition of mesenchymal proteins are associated with EMT and may have an
important role in the evaluation of CMC patients. The unique immunoexpression
pattern of Snai-1 could help to distinguish between an adenoma and a
non-metastatic carcinoma and seems to be related to conversion of myoepithelial
cells to a complete mesenchymal-like phenotype. Loss of E-cadherin and
cytokeratin and change of immunoexpression pattern of Snai-1, N-cadherin,
S100A4 and MMP-2 indicate the occurrence of EMT in canine mammary carcinomas
and should result in an en bloc resection or a close follow-up.