Expression profile of cancer-testis genes in transitional cell carcinoma of the bladder

Objectives: To explore the expression profile of multiple cancer testis (CT) genes in transitional cell carcinoma of bladder (TCC), and investigate its possible correlation with clinicopathologic characteristics. Methods: The mRNA expression of 6 CT genes was detected using reverse transcription polymerase chain reaction (RT-PCR) for 102 TCC samples (59 Ta-T1, 43 T2-T4, 44 G1, 32 G2, and 26 G3 samples) as well as the matching adjacent normal bladder mucosa for each sample. The MAGE-A3 protein expression was also determined by immunoblotting. Immunohistochemistry was performed in selected samples to confirm the MAGE-A3 protein expression. Results: The mRNA expression of all 6 CT genes was detected with relatively high frequencies in TCC tissues. The percent of samples positive for each gene in the TCC samples are: MAGE-A3, 58.8%; MAGE-AI, 56.9%; cTAGE-1, 52.9%; MAGE-A12, 51%; cTAGE-2, 49%; and NY-ESO-1, 45.1%. Furthermore, MAGE-A3 protein expression was positive in 52.9% of TCC tissues by immunoblotting. Immunohistochemistry showed an exclusively cytoplasmic staining pattern of MAGE-A3 protein. Neither CT gene mRNA expression nor MAGE-A3 protein expression was found in the adjacent normal tissue. There was no significant correlation between CT gene expression and clinicopathologic characteristics (P > 0.05). Conclusions: All six CT genes are highly expressed in TCC, and may serve as therapeutic targets of specific immunotherapy for TCC, especially in multi-antigen vaccine preparations. (C) 2012 Elsevier Inc. All rights reserved.