Vascular endothelial growth factor and epithelial cell adhesion molecule immunoexpression in enzootic nasal adenocarcinoma of goats

Abstract

Enzootic nasal adenocarcinoma (ENA) is a contagious and viral disease in sheep and goats. The disease leads to the death of the affected animals and causes economic losses in infected small ruminant flocks. Epithelial cell adhesion molecule (EpCAM) is a newly discovered tumor antigen, commonly expressed by several tumors occurring in humans. Vascular endothelial growth factor (VEGF) is a signal protein produced by cells that stimulate the formation of blood vessels and plays an important role in angiogenesis, essential for tumor development. In this study, ENA originating from the nasal mucosa is detected on histopathological and cytopathological examinations, with transmission electron microscopy confirming viral particles in the tumoral cells. The aim of this study was to examine VEGF and EpCAM immunoexpressions using streptavidin–biotin complex immunoperoxidase technique in 24 naturally ENA-affected goats. Sneezing, dyspnea, seromucous or purulent nasal discharge, exophthalmos, and weight loss were commonly observed clinical symptoms. The tumors located in the nasal cavity were generally unilateral and were bilateral in only two cases. Cytological examination of the tumoral masses revealed uniform epithelial cell clusters and abundant inflammatory reaction. On histopathological examination, tubular, papillary, or mixed types of ENA were diagnosed. On ultrastructural examination, intracytoplasmic, spherical, retrovirus-like particles were demonstrated. Immunohistochemically, strong positive reactions were reported for both EpCAM and VEGF in the cytoplasm of the tumor cells. Thus, this study showed that EpCAM and VEGF may have an important role in ENA pathogenesis.