EXPRESSION OF MAGE AND BAGE GENES IN JAPANESE BREAST CANCERS

Background. The MAGE and BAGE genes code for distinct antigens, which are recognized on melanoma cells as well as on other various tumor cel ls by autologous cytolytic T lymphocytes. These antigens may thus cons titute useful targets for specific immunotherapy, since no expression of MAGE or BAGE genes has been recognized in normal tissue except for the testis. Patients and methods. We studied the MAGE-1, MAGE-3, and B AGE gene expression observed in 49 Japanese breast cancers. Gene expre ssion was evaluated by reverse transcription polymerase chain reaction . Results. Out of 49 tumor tissue specimens of primary breast cancers, the expression of MAGE-1, -3 and BAGE was recognized in 15 (31%), 12 (24%), and 4 (8%) tumors, respectively. The expression of MAGE and BAG E genes is not recognized in normal breast tissue. The expression of t he MAGE-3 gene was frequently recognized in tumors with lymphatic and/ or vascular vessel permeations. Either MAGE-1 or -3 gene expressions w ere induced in 1 of 3 MAGE-1 negative breast cell lines or 1 of 3 MAGE -3 negative breast cell lines by the treatment with 5-aza-2'-deoxycyti dine. Conclusions: These findings suggest that: 1) the identification of such antigens coded by MAGE or BAGE genes may thus offer the possib ility of using specific immunotherapy, and 2) the use of a demethylati ng agent may increase the number of patients who might be candidates f or MACE specific immunotherapy.