Bladder Cancer (BLCa) inter-patient heterogeneity is the primary cause of treatment failure, suggesting that patients could benefit from a more personalized treatment approach. Patient-derived organoids (PDOs) have been successfully used as a functional model for predicting drug response in different cancers. In our study, we establish PDO cultures from different BLCa stages and grades. PDOs preserve the histological and molecular heterogeneity of the parental tumors, including their multiclonal genetic landscapes, and consistently share key genetic alterations, mirroring tumor evolution in longitudinal sampling. Our drug screening pipeline is implemented using PDOs, testing standard-of-care and FDA-approved compounds for other tumors. Integrative analysis of drug response profiles with matched PDO genomic analysis is used to determine enrichment thresholds for candidate markers of therapy response and resistance. Finally, by assessing the clinical history of longitudinally sampled cases, we can determine whether the disease clonal evolution matched with drug response.

Bladder cancer is a common malignancy that has a relatively poor outcome. Lack of culture models for the bladder epithelium (urothelium) hampers the development of new therapeutics. Here we present a long-term culture system of the normal mouse urothelium and an efficient culture system of human bladder cancer cells. These so-called bladder (cancer) organoids consist of 3D structures of epithelial cells that recapitulate many aspects of the urothelium. Mouse bladder organoids can be cultured efficiently and genetically manipulated with ease, which was exemplified by creating genetic knockouts in the tumor suppressors Trp53 and Stag2. Human bladder cancer organoids can be derived efficiently from both resected tumors and biopsies and cultured and passaged for prolonged periods. We used this feature of human bladder organoids to create a living biobank consisting of bladder cancer organoids derived from 53 patients. Resulting organoids were characterized histologically and functionally. Organoid lines contained both basal and luminal bladder cancer subtypes based on immunohistochemistry and gene expression analysis. Common bladder cancer mutations like TP53 and FGFR3 were found in organoids in the biobank. Finally, we performed limited drug testing on organoids in the bladder cancer biobank.

There are unmet clinical needs for novel therapeutic targets and drugs for bladder cancer. Majority of previous work relied on limited bladder cancer cell lines, which could not well represent the tumor heterogeneity and pathology of this disease. Recently, it has been shown that cancer organoids can recapitulate pathological and molecular properties of bladder cancer. Here, we report, by our knowledge, the first bladder cancer organoid-based small molecule screening for epigenetic drugs. We found that SRT1720, a Sirtuin 1 (SIRT1) activator, significantly inhibits the growth of both mouse and human bladder cancer organoids. And it also restrains the development of mouse in situ bladder cancer and human PDX bladder cancer. Mutation of Sirt1 promotes the growth of cancer organoids and decreases their sensitivity to SRT1720, which validate Sirt1 as the target of SRT1720 in bladder cancer. Mechanistically, SRT1720 treatment represses the hypoxia pathway through deacetylating HIF1α by activating Sirt1. Genetic or pharmaceutic inhibitions of HIF mimic the anti-tumor effect of SRT1720. Furthermore, the SIRT1-repressed gene signature is associated with the hypoxia target gene signature and poor prognosis in human bladder cancers. Thus, our study demonstrates the power of cancer organoid-based drug discovery and, in principle, identifies SRT1720 as a new treatment for bladder cancer.

Bladder cancer is a common and highly heterogeneous malignancy with a relatively poor outcome. Patient-derived tumor organoid cultures have emerged as a preclinical model with improved biomimicity. However, the impact of the different methods being used in the composition and dynamics of the models remains unknown. This study aims to systematically review the literature regarding patient-derived organoid models for normal and cancer tissue of the bladder, and their current and potential future applications for tumor biology studies and drug testing. A PRISMA-compliant systematic review of the PubMED, Embase, Web of Sciences, and Scopus databases was performed. The results were analyzed based on the methodologies, comparison with primary tumors, functional analysis, and chemotherapy and immunotherapy testing. The literature search identified 536 articles, 24 of which met the inclusion criteria. Bladder cancer organoid models have been increasingly used for tumor biology studies and drug screening. Despite the heterogeneity between methods, organoids and primary tissues showed high genetic and phenotypic concordance. Organoid sensitivity to chemotherapy matched the response in patient-derived xenograft (PDX) models and predicted response based on clinical and mutation data. Advances in bioengineering technology, such as microfluidic devices, bioprinters, and imaging, are likely to further standardize and expand the use of organoids.

Bladder cancer is the fifth most prevalent cancer in the U.S., yet is understudied, and few laboratory models exist that reflect the biology of the human disease. Here, we describe a biobank of patient-derived organoid lines that recapitulates the histopathological and molecular diversity of human bladder cancer. Organoid lines can be established efficiently from patient biopsies acquired before and after disease recurrence and are interconvertible with orthotopic xenografts. Notably, organoid lines often retain parental tumor heterogeneity and exhibit a spectrum of genomic changes that are consistent with tumor evolution in culture. Analyses of drug response using bladder tumor organoids show partial correlations with mutational profiles, as well as changes associated with treatment resistance, and specific responses can be validated using xenografts in vivo. Our studies indicate that patient-derived bladder tumor organoids represent a faithful model system for studying tumor evolution and treatment response in the context of precision cancer medicine.