SEQUENCE-ANALYSIS OF THE MAGE GENE FAMILY ENCODING HUMAN TUMOR-REJECTION ANTIGENS

The MAGE multigene family, which includes the MAGE-1 and -3 genes that encode tumor-rejection antigens on HLA-A1 recognized by cytotoxic T-lymphocytes (CTL), is preferentially expressed at the mRNA level on human malignant cells, but not on normal cells. However, little is known about the MAGE-4, -41 and -6 genes. In this study, we have amplified 1040 bp (MAGE-1), 1061 bp (MAGE-3 and-6) and 1064 bp (MAGE-4 and -41) cDNA fragments, including the entire coding sequences (927-951 bp), using the reverse transcription-polymerase chain reaction (RT-PCR) method followed by nucleotide (nt) sequencing. One member had greater than 80 or 66% homology with the other members at the nt or deduced amino acid (aa) levels, respectively. Higher homology was found between MAGE-3 and -6 (98% at the nt level) and also between MAGE-4 and -41 (98%). The results of this investigation demonstrated high homology, as well as the clear differences between the members of the MAGE family at the coding sequence level.