Melan-A/MART-1 antigen expression in cutaneous and ocular melanomas

The human immune repertoire appears to be capable of recognizing normal antigens expressed by tumor cells. Among these antigens, those of differentiation, characterized by a restricted tissue expression, could be of clinical interest since they may represent a target for immunotherapeutic protocols. In this context we have evaluated, in benign and malignant lesions of the melanocytic lineage, the expression of the Melan-A/MART-1 antigen, which has been shown to be recognized by T cells, of HLA-A2 melanoma patients. The immunohistochemical analysis conducted with a Melan-A/MART-1 monoclonal antibody demonstrated that the antigen expression does not correlate with transformation or tumor progression. At variable levels Melan-A/MART-1, differently from other differentiation antigens, is homogeneously expressed by multiple autologous metastases and by melanoma metastases at different body sites. This tissue distribution adds further biological support to the ongoing use of Melan-A/MART-1-related peptides in active immunotherapy.