Expression of MAGE and GAGE in high-grade brain tumors: A potential targetfor specific immunotherapy and diagnostic markers

The mRNA expression of the tumor-associated antigens MAGE and GAGE was exam ined in 60 high-grade brain tumors. This analysis was performed by using re verse transcription-PCR, Southern blotting, and sequencing. It was demonstr ated that, of the eight GAGE genes, GAGE-2 and -7 were expressed in five of seven normal brains. Four groups of tumors-adult glioblastoma multiforme ( n = 20), pediatric glioblastoma multiforme (n = 9), medulloblastomas (n = 1 5), and ependymomas (n = 14)-were analyzed for mRNA expression. The followi ng frequencies were observed: MAGE-1, 0, 0, 13, and 0%, respectively; MAGE- 2, 5, 11, 60, and 57%; MAGE-3 & -6, 0, 0, 13, and 0%; GAGE-1, 65, 11, 13, a nd 43%; and GAGE-3-6 and -8: 75, 78, 47, and 93%, respectively. Two unclass ified tumors expressed GAGE-3-6 and -8 only. The absence of GAGE-1 expressi on in normal brain, its relatively high frequency of expression in high-gra de brain tumors, and its unique 3' sequence, suggest it may represent a use ful target for specific immunotherapy. The detection method of reverse tran scription-PCR and Southern blotting may also be useful for rapid screening of biopsy specimens both for diagnostic purposes and to determine a patient 's eligibility for specific immunotherapy.