Mouse Anti-Human Uroplakin III monoclonal antibody, clone JID792

Approximately 50% of patients with muscle-invasive bladder cancer (MIBC) develop metastatic disease, which is almost invariably lethal. However, our understanding of pathways that drive aggressive behavior of MIBC is incomplete. Members of the FOXA subfamily of transcription factors are implicated in normal urogenital development and urologic malignancies. FOXA proteins are implicated in normal urothelial differentiation, but their role in bladder cancer is unknown. We examined FOXA expression in commonly used in vitro models of bladder cancer and in human bladder cancer specimens, and used a novel in vivo tissue recombination system to determine the functional significance of FOXA1 expression in bladder cancer. Logistic regression analysis showed decreased FOXA1 expression is associated with increasing tumor stage (p<0.001), and loss of FOXA1 is associated with high histologic grade (p<0.001). Also, we found that bladder urothelium that has undergone keratinizing squamous metaplasia, a precursor to the development of squamous cell carcinoma (SCC) exhibited loss of FOXA1 expression. Furthermore, 81% of cases of SCC of the bladder were negative for FOXA1 staining compared to only 40% of urothelial cell carcinomas. In addition, we showed that a subpopulation of FOXA1 negative urothelial tumor cells are highly proliferative. Knockdown of FOXA1 in RT4 bladder cancer cells resulted in increased expression of UPK1B, UPK2, UPK3A, and UPK3B, decreased E-cadherin expression and significantly increased cell proliferation, while overexpression of FOXA1 in T24 cells increased E-cadherin expression and significantly decreased cell growth and invasion. In vivo recombination of bladder cancer cells engineered to exhibit reduced FOXA1 expression with embryonic rat bladder mesenchyme and subsequent renal capsule engraftment resulted in enhanced tumor proliferation. These findings provide the first evidence linking loss of FOXA1 expression with histological subtypes of MIBC and urothelial cell proliferation, and suggest an important role for FOXA1 in the malignant phenotype of MIBC.

OBJECTIVES Current methods for reliable detection of bladder cancer have some limitations. Finding better noninvasive methods for detection of bladder cancer is an important topic in urology. We want to evaluate prospectively the early detection power of human uroplakin 3 A (UPK3A) for bladder cancer. METHODS Urine samples were obtained from 32 healthy volunteers, 44 patients with benign urological disorders and 122 patients with bladder cancer. The urine UPK3A levels were quantified by enzyme-linked immunosorbent assay. All the samples were also tested with NMP22 test and cytology examination. RESULTS The urinary UPK3A levels are uniformly elevated in bladder cancer patients than in those of normal volunteers and patients with benign urological disorders, and the differences in the mean urinary UPK3A levels of bladder cancer patients and those of normal individuals or benign urological disorders are statistically significant (P <.01). The receiver operating characteristic (ROC) curve of UPK3A showed an excellent area under the ROC curve of 0.907. In this study, the optimal combination of sensitivity and specificity were determined as 83% and 83%, for a cut-off value of absorbance unit 0.0685, respectively. The sensitivity of urine UPK3A, NMP22, and cytology for detecting bladder cancer were 83%, 58%, and 64%, respectively, whereas specificity was 83%, 75%, and 82%, respectively. CONCLUSIONS We conclude that individuals with bladder cancer have higher UPK3A values. Our data suggest that urine measurement of UPK3A is a sensitive marker for the detection of bladder cancer. However, it needs further studies in larger cohorts. UROLOGY 76: 514.e6-514.e11, 2010. (C) 2010 Elsevier Inc.