MAGE-E1, a new member of the melanoma-associated antigen gene family and its expression in human glioma

To unearth glioma-specific genes in human glioblastoma, the serial analysis of gene expression technique was applied to a primary glioblastoma, using cultured human astrocytes as a normal control. Among the top 147 most-expre ssed tags in glioblastoma, we found a tag, TTTT-GGG-TAT, that originated fr om an unidentified gene and which was not detected in human astrocyte cultu res, Real-time quantitative reverse transcription-PCR showed that MAGE-E1 e xpression was 2.6-15-fold enriched in glioblastoma relative to human astroc ytes. Expressed sequence tags containing this tag were homologous to the me lanoma-associated antigen gene (MAGE) Family, and this new cDNA, named MAGE -E1, was cloned by the 5 ' -rapid amplification of cDNA ends technique. Thr ee alternatively spliced variants (MAGE-E1a-c) were found, and deduced amin o acid sequence showed that MAGE-E1a and -E1b shared the MAGE-conserved reg ion, whereas -E1c did not. This suggests that although MAGE-E1c is expresse d from one of the MACE family, it has distinct functions from other members . Tissue distribution analysis showed that MAGE-E1 was distinct from other MAGEs. MAGE-E1 expression was detected only in brain and ovary among normal tissues. Interestingly, MAGE-E1a and/or -E1b were specifically expressed i n glioma cells among cancer cells. These results indicate that MAGE-E1 is a novel and glioma-specific member of MACE family.