Objective: To investigate the expression status of 11 different cancer/testis (CT) antigen genes in esophageal carcinoma.
Methods: Esophageal carcinoma tissue and adjacent normal esophageal mucosa taken from 35 esophageal carcinoma patients were assayed for the expression of 11 different CT antigen genes by RT-PCR techniques.
Results: Of the 11 CT antigen genes analyzed, none of them was expressed in normal esophageal mucosa. MAGE-3 was found to be the most frequently expressed in esophageal carcinoma tissues (62.9%), followed, in the order of expression frequency, by MAGE4 (31.4%), LAGE-1 (28.6%), MAGE-1 (25.7%), CT10 (20.0%), NY-ESO-1 (20.0%), CT7 (5.7%) and SCP1 (2.9%). No expression of SSX-1, SSX-2 and SSX-4 was found. Among the 35 cases, 28 (80.0%) expressed at least one CT antigen gene, 21 (60.0%) expressed more than 2 CT antigen genes, and 4 of the 21 (19.0%) expressed more than 4 CT antigens, which accounted for 11.4% of total number of patients (4/35). No CT antigen expression was found in the tumor tissue in 7 cases, including 5 cases in stage II and 1 case each in stage I and IV, respectively. Of the 11 CT genes examined, expression of 5 genes (NY-ESO-1, LAGE-1, MAGE-1, MAGE-3 and MAGE-4) was correlated with tumor progression. SCP-1 and CT10 expression was found more frequently in early stage patients. With progression of the disease, the frequency of co-expression of multiple CT antigen genes was significantly increased reaching 28.6% in stage III patients.
Conclusion: Of the 11 different CT antigen genes examined by RT-PCR in esophageal carcinoma, 8 genes were detected in various frequencies in 28 of the 35 esophageal cancer patients studied. They are candidate tumor-associated antigens in the preparation of tumor vaccines for immunotherapy in esophageal cancer patients.