MAGE-1 AND MAGE-3 OR MAGE-6 EXPRESSION IN NEUROBLASTOMA-RELATED PEDIATRIC SOLID TUMORS

MAGE-1 and MAGE-3 or -6 are genes encoding melanoma-rejection antigens recognized by cytotoxic T lymphocytes in an HLA-A1 restriction manner . MAGE-1 and MAGE-3 or -6 were expressed in 5/14 (36%) and 6/14 (43%) neuroblastoma (NB) cell lines, and in 20/41 (49%) and 24/41 (59%) clin ical NB-related tumors, respectively. Additionally, they were also exp ressed in pediatric tumors of other types such as rhabdomyosarcoma and Wilms' tumor. MAGE-1 expression at a functional level in tumor cells was confirmed by the cytotoxicity assay using MAGE-1-specific tumor-in filtrating lymphocytes (TIL). In clinical NB-related tumors, MAGE-3 or -6 expression demonstrated an inverse correlation to clinical stage. Furthermore, although the sample number was small, the incidence of MA GE-1 and/or MAGE-3 or -6 expression was significantly correlated to th e absence of metastasis and a move favorable clinical outcome (p < 0.0 5). These results may suggest that NB cells silent far the expression of MAGE genes escape from the host anti-tumor immune response and cons equently retain a growth advantage. Finally, NB-related tumors could b e reliable candidates for immunotherapy targeted towards MAGE gene pro ducts. (C) 1996 Wiley-Liss, Inc.