Expression of MAGE-1, -2, and -3 genes in gastric carcinomas and cancer cell lines derived from Korean patients.

We investigated the expression of MAGE-1, -2, and -3 genes in tissues of 51 gastric carcinomas from Korean patients and in 11 gastric cancer cell lines established in Korea using reverse transcriptase-polymerase chain reaction along with immunohistochemical analyses and DNA sequencing. Among the 51 gastric carcinomas, MAGE-1, -2, and -3 genes were expressed in 16 (31%), 22 (43%), and 17 (33%), respectively, and 31 (60%) expressed at least one of the three genes. In contrast, none of the three MAGE genes were expressed in normal sites of gastric tissue from each cancer patient. Out of 11 gastric cancer cell lines, MAGE-1, -2, and -3 genes were expressed in two (18%), five (46%), and four (36%), respectively. According to the clinicopathological analysis, the expression of any of the three MAGE genes was not significantly correlated with several clinicopathological factors except histologic types (p= 0.067). Immunohistochemical analyses identified positive staining with monoclonal antibodies 77B and 57B specifically against MAGE-1 and -3 proteins, respectively, in nuclei and cytoplasms of cells in mRNA-positive tumor tissue. These findings suggest the possibility as a target for tumor-specific immunotherapy for Korean patients.