Objective: The 12 members of the human melanoma antigen-encoding (MAGE) gene family encode tumor-specific peptide antigens. Some antigens coded by the MAGE genes are potentially useful for cancer-specific immunotherapy. However, little information on the expression of these genes in human colon carcinomas is available. We investigated the expression of 10 of the 12 genes in human colon tissue.
Design: Eighty pairs of tumor and normal tissue samples from the human colon were studied by means of reverse transcription-polymerase chain reaction.
Results: None of the genes was expressed in the 80 control samples of normal tissue. On the other hand, expression was recognized in tumor samples, ranging from 5% of samples for MAGE-6 to 44% for MAGE-8. Seventy of the 80 tumor samples (88%) expressed at least 1 of the 10 MAGE genes. The frequency of liver metastasis was significantly higher in cases with tumor samples that expressed MAGE-3 than in those that did not express this gene. This tendency was not observed for other members of the MAGE gene family. No significant differences were observed in the other clinicopathologic factors between any MAGE-positive and -negative tumor cases.
Conclusions: The MAGE genes were exclusively expressed in carcinoma tissues and not in normal tissues of the colon. The finding that nearly 90% of tumors expressed at least one MAGE gene indicates the possible clinical use of this gene for both immunotherapy and molecular diagnosis.