OVERALL PROJECT SUMMARY Bladder cancer (BC) is the second most common urologic malignancy affecting 573,278 people worldwide in 2020. Pathologically, BC is diagnosed as non-muscle-invasive (NMI) and muscle-invasive (MI) disease. Here we define early bladder lesions as NMIBC. Major clinical gaps in NMIBC include i) lack of mechanistic insights defining NMIBC progression, and ii) lack of platform for risk stratification of NMIBC that recur but never progress (“non-progressors”), from those that progresses into MIBC (“progressors”) and consequently demonstrate poor prognosis. The goal of our Center is to tackle this clinical issue by deciphering the underlying mechanisms restraining or promoting the progression of early lesions (Project 1 & 2), and to leverage this novel biology as candidate biomarkers to risk-stratify aggressive NMIBC (Project 3). This proposal seeks to shift the current research paradigm in the field of NMIBC, by proposing a conceptually innovative tug-of-war between a tumor- restraining (Project 1) and a tumor-promoting mechanism (Project 2) in determining the outcome of early bladder lesions/NMIBC in becoming “progressors” or “non-progressors” (Project 3). Clinically, why “non-progressors” often recur but seldom progress, and what are the driving forces advancing “progressors” into MIBC with poor survival remain fundamental questions in field. Our tug-of-war hypothesis with two opposing forces is conceptually different to most other studies, which primarily focus on one side of the coin. Further, the integration of knowledge from Project 1 and 2 as a unified spatial proteomics and transcriptomics map by the Shared Resource Core will reveal spatial and temporal relationships between distinct fibroblast populations with opposing functions, their physical interactions with tumor and immune cell clusters, as well as their relationship to the biomarkers from Project 3. Benchmark of success: The knowledge gained here will shift clinical practice paradigm, by informing future NIMBC management through 1) the development of novel urinary profiling strategies that could risk stratify aggressive NMIBC (Project 1-3); 2) the identification of targets for future precision intervention, either by enhancing/sustaining the tumor-restraining mechanisms (Project 1) and/or inhibiting the tumor-promoting mechanisms (Project 2). The overall success of our program is further ensured by an extraordinary multi-investigator team that integrates three “organ-specific” bladder cancer investigators within Cedars-Sinai Medical Center. All have active R01s and individual NCI-funding track record in performing basic science research, translational bladder cancer research, or leading multi-center clinical trials on the discovery and validation of biomarkers. Finally, they propose to collect valuable retrospective and prospective NMIBC cohorts, which are essential to address the clinical questions posed within this proposal and will become available to the research community as a shared resource to advance the field.

OVERALL PROJECT NARRATIVE Bladder cancer is the second most common urologic malignancy; yet, remained a significantly underfunded and understudied cancer type. Major clinical gaps in early bladder lesions [defined as non-muscle invasive bladder cancer (NMIBC)] include 1) lack of mechanistic insights defining NMIBC progression, and 2) lack of platform for risk stratifying NMIBC that recur but never progress, from those that progresses into MIBC and consequently demonstrate poor prognosis. The knowledge gained by our Center will inform future NIMBC management through 1) the development of novel urinary profiling strategies that could risk stratify aggressive NMIBC (Project 1-3); 2) the identification of targets for future precision intervention, either by enhancing/sustaining the tumor- restraining mechanisms (Project 1) and/or inhibiting the tumor-promoting mechanisms (Project 2).