Bladder Cancer Patient-derived Organoids and Avatars for Personalized Cancer Discovery

Organoid models in bladder cancer: From bench to bedside?

Background

Bladder cancer (BC), one of the most prevalent and aggressive urological malignancies, poses significant challenges in diagnosis, treatment, and recurrence management. Patient-derived organoid provides new directions for the precision diagnosis and treatment of bladder cancer.

Objective

To make a comprehensive summary of the current bladder cancer organoid studies.

Methods

A comprehensive database search was conducted to provide an in-depth overview of the current state of bladder cancer organoid models, with a focus on their applications in basic research, clinical translation, and therapeutic discovery.

Results

We summarized the current bladder cancer organoid studies, highlighting their advantages, such as genetic fidelity and high-throughput drug screening capabilities. Additionally, we also address the challenges, including their limited representation of the tumour microenvironment and technical complexity. Finally, we discuss future directions, including the integration of immunotherapy, the development of co-culture systems, and the exploration of non-invasive sampling methods and organoid-on-chip systems.

Conclusions

Traditional pre-clinical models have inherent limitations in mimicking the complexity of human tumours. The emergence of organoid technology has offered a groundbreaking approach to address this challenge, providing an innovative tool for studying tumour biology, genetic alterations, drug screening, and personalized medicine in bladder cancer.

Validation of hyperthermia as an enhancer of chemotherapeutic efficacy: insights from a bladder cancer organoid model

OBJECTIVE

This study aimed to evaluate the combined efficacy of hyperthermia and chemotherapy using a bladder cancer organoid model and to explore hyperthermia-related molecular pathways.

METHOD

Tumor organoids were generated by embedding RT4 bladder cancer cells into Matrigel. The resulting organoids were treated with pirarubicin or gemcitabine at 37 °C or 42 °C. Proliferation was determined by Ki67 immunofluorescence staining, and apoptosis was assessed using a TdT-mediated dUTP nick end labeling (TUNEL) assay. RNA sequencing was used to identify the differentially expressed genes.

RESULTS

Bladder cancer organoids were successfully established and exhibited robust proliferative abilities. Treatment with gemcitabine or pirarubicin under hyperthermic conditions caused pronounced structural damage to the organoids and increased cell death compared to that in the normothermically treated group. Furthermore, Ki67 labeling and TUNEL assays showed that the hyperthermia chemotherapy group showed a significantly reduced proliferation rate and high level of apoptosis. Finally, RNA sequencing revealed the IFN-γ signaling pathway to be associated with hyperthermia.

CONCLUSION

Overall, hyperthermia combined with chemotherapy exerted better therapeutic effects than those of normothermic chemotherapy in grade 1-2 non-muscle-invasive bladder cancer, potentially through activation of the IFN-γ-JAK-STAT pathway.

Integrating novel immunotherapeutic approaches in organ-preserving therapies for bladder cancer

Bladder cancer (BC) is a prevalent malignancy with significant morbidity and mortality. Over the years, the landscape of bladder cancer treatment has witnessed notable advancements, particularly in the realm of immunotherapy. Immunotherapy has emerged as a promising adjunct to organ-preserving approaches, harnessing the immune system's potential to target and eliminate cancer cells. Organ preservation strategies offer viable alternatives to radical cystectomy to avoid the morbidities associated with radical surgery, as well as to respond to the needs of patients unfit for or who have refused surgery. However, the challenge lies in achieving durable disease control while minimizing treatment-related toxicities. This review highlights the significance of immune checkpoint inhibitors, such as anti-programmed cell death 1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) antibodies, in the treatment of localized bladder cancer. The clinical efficacy of immune checkpoint inhibitors, as both neoadjuvant and adjuvant therapies in combination with radiation or chemotherapy, is discussed. Moreover, the potential of immunotherapies beyond immune checkpoint inhibition, including combinations with bacillus Calmette-Guérin (BCG) instillations and/or investigational gene therapies, is explored. Furthermore, the predictive value of the tumour immune microenvironment for the success of these strategies is examined. Understanding the complex interplay between tumour immunity and therapeutic interventions can aid in identifying predictive biomarkers and tailoring personalized treatment strategies. Further research and clinical trials are warranted to optimize the use of immunotherapy in conjunction with organ-preserving therapies, potentially leading to enhanced patient outcomes and quality of life.

Patient-derived bladder cancer organoid model to predict sensitivity and feasibility of tailored precision therapy

Background

Bladder cancer is a common and highly heterogeneous malignant tumor with a relatively poor prognosis. Thus, personalized treatment strategies for bladder cancer are essential for improving patient outcomes.

Materials and methods

We developed an efficient 3-dimensional in vitro organoid culture system for bladder cancer organoids (BCOs), which maintains the homology with the original patient tumors and the heterogeneity between different individuals. In addition, we constructed chimeric antigen receptor (CAR)-T cells targeting B7H3 and evaluated the antitumor function of CAR-T cells by coculturing them with BCOs.

Results

The BCOs closely resembled the characteristics of human tumors and were used to test individual sensitivity to platinum-based drugs and olaparib therapy. Coculture with CAR-T cells demonstrated specific antigen recognition and immune activation, indicating their potential in immunotherapy.

Conclusions

Our study highlights the potential of BCOs to facilitate the development of personalized medicine for bladder cancer and improve the efficiency of drug discovery for bladder cancer therapy.

Patient-derived organoids identify tailored therapeutic options and determinants of plasticity in sarcomatoid urothelial bladder cancer

Sarcomatoid Urothelial Bladder Cancer (SARC) is a rare and aggressive histological subtype of bladder cancer for which therapeutic options are limited and experimental models are lacking. Here, we report the establishment of a long-term 3D organoid-like model derived from a SARC patient (SarBC-01). SarBC-01 emulates aggressive morphological, phenotypical, and transcriptional features of SARC and harbors somatic mutations in genes frequently altered in sarcomatoid tumors such as TP53 (p53) and RB1 (pRB). High-throughput drug screening, using a library comprising 1567 compounds in SarBC-01 and conventional urothelial carcinoma (UroCa) organoids, identified drug candidates active against SARC cells exclusively, or UroCa cells exclusively, or both. Among those, standard-of-care chemotherapeutic drugs inhibited both SARC and UroCa cells, while a subset of targeted drugs was specifically effective in SARC cells, including agents targeting the Glucocorticoid Receptor (GR) pathway. In two independent patient cohorts and in organoid models, GR and its encoding gene NR3C1 were found to be significantly more expressed in SARC as compared to UroCa, suggesting that high GR expression is a hallmark of SARC tumors. Further, glucocorticoid treatment impaired the mesenchymal morphology, abrogated the invasive ability of SARC cells, and led to transcriptomic changes associated with reversion of epithelial-to-mesenchymal transition, at single-cell level. Altogether, our study highlights the power of organoids for precision oncology and for providing key insights into factors driving rare tumor entities.