Significance of Angiogenic Growth Factors in Bovine Ocular Squamous Cell Carcinoma

Bovine ocular squamous cell carcinoma (BOSCC) is the most common and economically significant neoplasm of the eye in cattle. This study investigated the role of angiogenic growth factors in the pathogenesis of BOSCC. Eighteen cases of BOSCC were classified histopathologically according to the degree of differentiation. Normal upper and lower eyelids and third eyelids collected from the right and left eyes of six healthy cattle aged 1-3 years, that had been presented for slaughter to abattoirs, served as controls. Transcription of genes encoding the angiogenic growth factors vascular endothelial growth factor-C (VEGF-C), basic fibroblast growth factor (bFGF), platelet-derived growth factor-C (PDGF-C) and platelet-derived growth factor receptor-α (PDGFR-α) was determined by quantitative real-time polymerase chain reaction (RT-PCR) in tissue obtained from paraffin wax blocks. Immunohistochemistry (IHC) was utilized to detect intensity of expression and tissue distribution of these growth factors. IHC results revealed that bFGF and PDGF-C were elevated significantly (P >0.05) and VEGF-C expression was decreased in BOSCC compared with healthy control tissue. PDGR-α expression was elevated; however, the difference, compared with control tissues, was not significant. RT-PCR results showed an inverse relationship to the results of IHC; where protein levels were elevated their corresponding mRNA levels were decreased or vice-versa. Angiogenic regulators therefore appear to play a role in the pathogenesis of BOSCC.