MOLECULAR-DETECTION OF TUMOR-ASSOCIATED ANTIGENS SHARED BY HUMAN CUTANEOUS MELANOMAS AND GLIOMAS

Both melanocytes and glial cells are derived embryologically from the neural ectoderm. Their malignant transformed counterparts, melanoma an d glioma cells, respectively, may share common antigens. Numerous tumo r-associated antigens have been identified in melanomas but only a few , in gliomas, Using an established reverse transcriptase polymerase ch ain reaction plus Southern blot assay, we compared the mRNA expression of melanoma-associated antigens (MAAs) of melanomas to brain tumors p rimarily derived from glial cells. The MAAs studied included tyrosinas e (Tyr), tyrosinase-related protein-1 and -2 (TRP-1 and TRP-2), gp100, human melanoma antigen-encoding genes 1 and 3 (MAGE-1 and MAGE-3), an d melanomatransferrin (P37), Glioblastoma multiforme (n = 21), anaplas tic astrocytoma (n = 3), ependymoma (n = 2), meningioma (n = 3), oligo dendroglioma (n 1), and melanoma (n = 12) tumor specimens were assayed for MAA mRNA expression, Glioblastoma multiforme, astrocytoma, and me lanoma cell lilies were also assayed, We observed that individual MAA mRNAs were expressed in these brain tumours and cell lines at varying frequencies. The melanogenesis-pathway-related MAAs Tyr, TRP-1, TRP-2, and gp100 mRNAs were also expressed at different levels in normal bra in tissues but at a much lower frequency than in glioblastoma multifor me and melanoma, MAGE-1 and MAGE-3 mRNA were expressed in different ty pes of tumor specimens and cell lines brit never in normal brain tissu e. Tumor antigen p97 was expressed in all types of tumors and also in normal brain tissues, These studies demonstrate that melanomas and pri mary brain tumors express common MAAs and could be exploited in patien ts with malignant glioma by active specific immunotherapy against thes e common MAAs.