Background & aims: The genes MAGE-1 and MAGE-3 both encode melanoma peptide antigens recognized by major histocompatibility complex-restricted cytotoxic T lymphocytes. The antigens may be a target for immunotherapy. There is, however, little information on the expression of these genes in gastric carcinomas. Therefore, the expression of MAGE genes in gastric carcinomas was evaluated.
Methods: The expression of MAGE-1, MAGE-2, and MAGE-3 genes in tumors and corresponding normal tissue specimens was studied using a reverse-transcription polymerase chain reaction. The results were analyzed according to clinicopathologic factors of the tumor.
Results: In the 68 gastric carcinomas studied, MAGE-1, MAGE-2, and MAGE-3 messenger RNA were detected in 41%, 31%, and 38%, respectively. Fifty percent of the gastric carcinomas expressed at least one of the MAGE genes. Messenger RNA for the three MAGE proteins was not detected in normal gastric tissue. MAGE gene expression in gastric carcinomas was not associated with a significant clincopathology of the tumor. However, gene expression was lower in mucinous carcinomas (3 of 10).
Conclusions: MAGE-1, MAGE-2, and MAGE-3 are expressed in a high percentage of gastric carcinomas. These tumor rejection antigens may provide tumor-specific targets for immunotherapy.