Expression levels of angiogenic growth factors in feline squamous cell carcinoma.

Squamous cell carcinoma (SCC) is the most common malignant neoplasm of the skin in cats. Tumour angiogenesis is the pivotal event for tumour progression and metastasis. We assessed protein and gene expression of angiogenic growth factors including bFGF, VEGF-C, TGF-β, PDGF-A, PDGF-C and PDGFR-α that possibly contribute to the angiogenic phenotype of feline SCC (FSCC) and could, therefore, be a good target in the treatment of SCC. In the present study, a total of 27 FSCC cases were investigated. Tumour cases were histopathologically classified as well differentiated (10/27), moderately differentiated (5/27), and poorly differentiated (12/27). The expression levels of the growth factors were detected using immunohistochemistry and assessed semi-quantitatively. Growth factor expression levels were evaluated at different locations: in the oral region, in areas exposed to solar UV radiation including the ears, eyelids and nasal planum, and other miscellaneous locations. Our findings have revealed that FSCC arising from different anatomical sites of the body and showing differences in aggressiveness, metastasis, and prognosis may be angiogenesis dependent, and angiogenic key regulators could play a role in the development of FSCC.