Immunohistochemical characterization of galectin-3 as a prognostic tool in canine oral melanomas

Abstract

Melanomas originate from melanocytes or melanoblasts and are locally aggressive, with high metastatic potential and represent 4% of all malignancies in dogs. Melanomas may affect the oral cavity, skin and eyes. Melanomas in domestic animals have poor prognosis, because it is usually diagnosed at an advanced stage, in which the excision is uneffective. Galectin-3 is a protein found mainly in the cytoplasm and has several biological functions associated with cell proliferation, adhesion, migration, invasion, angiogenesis and apoptosis, depending on the location. Despite being considered a prognostic marker for certain cancer types, further studies are needed to elucidate its relationship with neoplastic biology and prognosis. This study aims to characterize the immunohistochemical expression of galectin-3 in malignant canine oral melanoma, comparing the results with other already established prognostic markers (Ki67, nuclear atypia and mitotic index). Surgical samples of canine oral melanomas will be evaluated and clinically followed-up for a minimum period of 180 days. A primary polyclonal rabbit anti-Galectin-3 antibody will be applied. Proliferative indexes will be determined according to previous studies. Nuclear atypia will be evaluated by computerized morphometric analysis with the aid of software Image ProPlus® and, for statistical analysis, the significance level will be set as 5%. (AU)