Testis expressed 19 is a novel cancer-testis antigen expressed in bladder cancer

Bladder cancer exhibits high mortality as a result of limited therapeutic options and a high recurrence rate. Accordingly, novel treatments such as immunotherapy have emerged as promising therapeutic modalities to prolong overall patient survival and effect a disease cure, which has renewed enthusiasm for the identification of tumor-specific target antigens. Cancer-testis (CT) antigens are recognized as ideal targets for immunotherapy because of their expression features and high immunogenicity profiles. Here, we investigate the expression pattern of a novel CT antigen, testis-expressed 19 (TEX19), in patients with bladder carcinoma and among multiple human tissues. Six bladder cancer cell lines (T24, UM-UC-3, J82, 5637, SW780, and RT4) were also analyzed for TEX19 expression. Our results reveal that TEX19 expression in normal tissue is restricted to human testis. In addition, TEX19 mRNA expression was detected in 60 % (24/40) bladder cancer samples, whereas 58.20 % (110/189) were positive for TEXT19 protein expression. Compared to low-grade tumors, TEX19 exhibited increased expression in high-grade tumors, from 53.69 to 77.14 %, respectively ( P = 0.011). TEX19 was also expressed in all six bladder cancer cell lines. Together, our findings suggest that TEX19 represents a novel CT gene and might play a role in the progression of bladder cancer and that this gene therefore provides a potential target for immunotherapy treatment strategies against bladder cancer.