EXPRESSION SPECTRUM OF MELANOMA ANTIGEN-ENCODING GENE FAMILY MEMBERS IN COLORECTAL-CARCINOMA

Objective.-The 12 members of the human melanoma antigen-encoding (MAGE ) gene family encode tumor-specific peptide antigens. Some antigens co ded by the MAGE genes are potentially useful for cancer-specific immun otherapy. However, little information on the expression of these genes in human colon carcinomas is available. We investigated the expressio n 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.-Non e of the genes was expressed in the 80 control samples of normal tissu e. On the other hand, expression was recognized in tumor samples, rang ing 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 fr equency of liver metastasis was significantly higher in cases with tum or samples that expressed MAGE-3 than in those that did not express th is gene. This tendency was not observed for other members of the MAGE gene family No significant differences were observed in the other clin icopathologic factors between any MAGE-positive and -negative tumor ca ses. Conclusions.-The MAGE genes were exclusively expressed in carcino ma tissues and not in normal tissues of the colon. The finding that ne arly 90% of tumors expressed at least one MAGE gene indicates the poss ible clinical use of this gene for both immunotherapy and molecular di agnosis.