RESUMO
Nestin is an intermediate filament expressed in proliferating neural progenitor cells and has been considered as a stem cell marker. Nestin is also found in melanoma and we recently demonstrated that its expression in melanoma cell lines is regulated by the transcription factors SOX9 and SOX10, but not BRN2. In this study, the expression levels of nestin, BRN2, SOX9 and SOX10 were analysed in tissues of melanoma (n = 78) and melanocytic nevi (n = 26) by immunohistochemistry. All proteins were highly expressed in primary and metastatic melanomas and, apart from BRN2, showed much lower levels in melanocytic nevi. Significant coexpression of nestin with SOX9 and SOX10 was found in primary melanoma confirming our in vitro data. Correlation analysis with clinicopathological data revealed that nestin was significantly associated with presence of ulceration in primary tumors and SOX9 with more advanced stage of disease. Our data reveal that SOX9 and SOX10 are highly expressed in melanoma and seem to have a regulatory role in nestin expression. The association with ulceration and advanced-stage tumors, respectively, suggests that nestin and SOX9 may be negative prognostic markers in melanoma.