The Notch signaling pathway controls cell fates through interactions between neighboring cells by positively or negatively affecting the processes of proliferation, differentiation and apoptosis in a context-dependent manner. This pathway has been implicated in human cancer as both an oncogene and a tumor suppressor. Here we report new inactivating mutations in Notch pathway components in over 40% of human bladder cancers examined. Bladder cancer is the fourth most commonly diagnosed malignancy in the male population of the United States. Thus far, driver mutations in fibroblast growth factor receptor 3 (FGFR3) and, less commonly, in RAS proteins have been identified. We show that Notch activation in bladder cancer cells suppresses proliferation both in vitro and in vivo by directly upregulating dual-specificity phosphatases (DUSPs), thus reducing the phosphorylation of ERK1 and ERK2 (ERK1/2). In mouse models, genetic inactivation of Notch signaling leads to Erk1/2 phosphorylation, resulting in tumorigenesis in the urinary tract. Collectively our findings show that loss of Notch activity is a driving event in urothelial cancer.

Purpose: Urothelial bladder cancer presents high recurrence rates, mandating continuous monitoring via invasive cystoscopy. The development of noninvasive tests for disease diagnosis and surveillance remains an unmet clinical need. In this study, validation of two urine-based biomarker panels for detecting primary and recurrent urothelial bladder cancer was conducted.Experimental Design: Two studies (total n ¼ 1,357) were performed for detecting primary (n ¼ 721) and relapsed urothelial bladder cancer (n ¼ 636). Cystoscopy was applied for detecting urothelial bladder cancer, while patients negative for recurrence had follow-up for at least one year to exclude presence of an undetected tumor at the time of sampling. Capillary electrophoresis coupled to mass spectrometry (CE-MS) was employed for the identification of urinary peptide biomarkers. The candidate urine-based peptide biomarker panels were derived from nested cross-sectional studies in primary (n ¼ 451) and recurrent (n ¼ 425) urothelial bladder cancer.Results: Two biomarker panels were developed on the basis of 116 and 106 peptide biomarkers using support vector machine algorithms. Validation of the urine-based biomarker panels in independent validation sets, resulted in AUC values of 0.87 and 0.75 for detecting primary (n ¼ 270) and recurrent urothelial bladder cancer (n ¼ 211), respectively. At the optimal threshold, the classifier for detecting primary urothelial bladder cancer exhibited 91% sensitivity and 68% specificity, while the classifier for recurrence demonstrated 87% sensitivity and 51% specificity. Particularly for patients undergoing surveillance, improved performance was achieved when combining the urine-based panel with cytology (AUC ¼ 0.87).Conclusions: The developed urine-based peptide biomarker panel for detecting primary urothelial bladder cancer exhibits good performance. Combination of the urine-based panel and cytology resulted in improved performance for detecting disease recurrence.

Of the most important clinical needs for bladder cancer (BC) management is the identification of biomarkers for disease aggressiveness. Urine is a "gold mine" for biomarker discovery, nevertheless, with multiple proteins being in low amounts, urine proteomics becomes challenging. In the present study we applied a fractionation strategy of urinary proteins based on the use of immobilized metal affinity chromatography for the discovery of biomarkers for aggressive BC. Urine samples from patients with non invasive (two pools) and invasive (two pools) BC were subjected to immobilized metal affinity chromatography fractionation and eluted Bladder cancer (BC) 1 is the second in incidence and mortality cancer of the genitourinary system (1) and estimated to be the ninth most common malignancy (2). It is associated with a high recurrence rate underscoring the need for continuous surveillance following initial treatment. Cystoscopy still remains the gold standard for diagnosis and follow-up monitoring of bladder cancer. However, it is an invasive and unpleasant procedure, rendering particularly the regular surveillance program (e.g. cystoscopy every three months for the first year following initial diagnosis) not well accepted by the patients (3, 4). Urine Cytology is a noninvasive current detection tool for BC, suffering however from suboptimal sensitivity, especially for low grade tumors and being subjected to interobserver variability (5). The invasive nature of cystoscopy and the low effectiveness of cytology have prompted the search for novel and better ways to diagnose the disease with special emphasis on the early detection of disease recurrences and/or progression.Urine is regularly used in clinical practice and yields a wealth of information about the state of an individual's health. Because it can be collected in a noninvasive way it is more accessible than plasma or serum. In addition, there is no need for trained personnel for urine collection. Urine contains cells and cellular debris, inorganic ions (K ϩ , Na ϩ , Cl Ϫ , and Ca ϩ2 ), organic molecules (urea, uric acid, and creatinine) and proteins. If renal function is normal, urinary protein content is less

Purpose: Minimally invasive methods of predicting the risk of muscle-invasive urothelial bladder carcinoma may expedite appropriate therapy and reduce morbidity and cost. Experimental Design: Here, capillary electrophoresis coupled mass spectrometry was used to identify urinary polypeptide bladder cancer biomarkers in 127 patients. These markers were used to construct a panel discriminating muscle-invasive from noninvasive disease, which was refined in 297 additional samples from healthy volunteers, patients with malignant and nonmalignant genitourinary conditions. Sequencing of panel polypeptides was then done. Finally, the ability of the panel to predict muscle-invasive disease was evaluated prospectively in 130 bladder carcinoma patients. Four sequenced polypeptides formed a panel predictive of muscle-invasive disease. Conclusions: Use of urinary peptides seems promising in estimating the probability a patient harbors muscle-invasive urothelial bladder cancer. These peptides may also shed novel insights into the biology of bladder tumor progression not obtainable by other methods. Clinical trials seem warranted to evaluate the effect of this approach on practice.