Intermediate Filaments, P53 Gene, Cellular Proliferation, Metastasis and Apoptosis in Feline Squamous Cell Carcinomas

Abstract

In this study, intermediate filaments, Pan Cytokeratin (Pan CK), Vimentin, Desmin and S-100 were evaluated to reveal the cellular origin of feline SCCs. Alpha-Smooth Muscle Actin (α-SMA) for cancer-related fibroblasts (CAFs) in the tumor microenvironment, and p53, a tumor suppressor gene, were investigated. Proliferating Cell Nuclear Antigen (PCNA) expression was evaluated for the cell proliferation index. Matrix Metalloproteinase-9 (MMP-9) immunoreactivity was evaluated for the metastasis and invasion capacity. In addition, it is aimed to reveal the expressions of proapoptotic Bax gene, antiapoptotic Bcl-2 gene, caspase-dependent pathway Caspase-3 and caspase-independent pathway Apoptosis Inducing Factor (AIF) for apoptosis mechanism. Biopsy samples taken from 7 cats brought to Department of Pathology for routine histopathological examination were used in this study. Tumor tissue samples were fixed in 10% formaldehyde solution. Serial sections of 5 μm thickness were taken from the paraffin blocks prepared after routine tissue follow-up procedures. Hematoxylin & Eosin (H&E) staining was performed on the sections. Avidin-Biotin Peroxidase-Technique (ABC) was used as immunohistochemical staining. It was determined that the tumors had epithelial-mesenchymal transition, exhibited a very high proliferation index, had p53 mutation, and showed low metastasis/high invasion capacity. It was revealed that Bax/Bcl-2 ratio increased in favor of proapoptotic Bax, and caspase-independent apoptosis was more dominant than caspase-dependent apoptosis.