Immunohistochemical Expression of Tensin-4/CTEN in Squamous Cell Carcinoma in Dogs.

Simple Summary: Tensins are a family of focal adhesion proteins that connect the extracellular matrix (ECM) to the cytoskeletal networks, mainly through integrin receptors and their associated protein complexes. To investigate, for the first time in canine species, the expression of CTEN was evaluated in oral and cutaneous squamous cell carcinoma samples from several dog breeds and submitted to immunohistochemistry technique. The results reveal a higher level of expression associated with the highest grades of the tumor, evidencing that this protein is more expressed in the highest grades of squamous cell carcinoma, probably due to its involvement in tumor progression. In the present study, we demonstrated, for the first time, CTEN clinical significance in a canine squamous cell carcinoma, and, to our knowledge, this is also the first time that the CTEN expression pattern is linked to the canine species. C-terminal tensin-like (tensin-4/TNS4/CTEN) is the fourth member of the tensin family, frequently described as displaying oncological functions, including cellular migration, invasion, adhesion, growth, metastasis, epithelial to mesenchymal transition, and apoptosis, in several different types of cancer. To investigate, for the first time, the clinical significance of CTEN in squamous cell carcinoma (SCC) of dogs, we studied a total of 45 SCC sections from various dog breeds. The mean age of the affected dogs was 8.9 ± 3.6 years. Immunohistochemistry confirmed strong cytoplasmatic CTEN expression in the basal layer of the epidermis next to the tumor. We detected high CTEN expression associated with the highest grade of the tumor (grade III) and observed 100% of immunopositivity for this tumor grading (p < 0.0001). These data suggest that CTEN is an oncogene in SCC of dogs and a promising biomarker and a therapeutic target for dogs affected by SCC. [ABSTRACT FROM AUTHOR]