Urine-derived bladder cancer organoids (urinoids) as a tool for cancer longitudinal response monitoring and therapy adaptation

BACKGROUND

Bladder cancer is one of the most common cancer types worldwide. Generally, research relies on invasive sampling strategies.

METHODS

Here, we generate bladder cancer organoids directly from urine (urinoids). In this project, we establish 12 urinoid lines from 22 patients with non-muscle and muscle-invasive bladder tumours, with an efficiency of 55%.

RESULTS

The histopathological features of the urinoids accurately resemble those of the original bladder tumours. Genetically, there is a high concordance of single nucleotide polymorphisms (92.56%) and insertions & deletions (91.54%) between urinoids and original tumours from patient 4. Furthermore, these urinoids show sensitivity to bladder cancer drugs, similar to their tissue-derived organoid counterparts. Genetic analysis of longitudinally generated tumoroids and urinoids from one patient receiving systemic immunotherapy, identify alterations that may guide the choice for second-line therapy. Successful treatment adaptation was subsequently demonstrated in the urinoid setting.

CONCLUSION

Therefore, urinoids can advance precision medicine in bladder cancer as a non-invasive platform for tumour pathogenesis, longitudinal drug-response monitoring, and therapy adaptation.

Early invasion of the bladder wall by solitary bacteria protects UPEC from antibiotics and neutrophil swarms in an organoid model

Recurrence of uropathogenic Escherichia coli (UPEC) infections has been attributed to reactivation of quiescent intracellular reservoirs (QIRs) in deep layers of the bladder wall. QIRs are thought to arise late during infection following dispersal of bacteria from intracellular bacterial communities (IBCs) in superficial umbrella cells. Here, we track the formation of QIR-like bacteria in a bladder organoid model that recapitulates the stratified uroepithelium within a volume suitable for high-resolution live-cell imaging. Bacteria injected into the organoid lumen enter umbrella-like cells and proliferate to form IBC-like bodies. In parallel, single bacteria penetrate deeper layers of the organoid wall, where they localize within or between uroepithelial cells. These "solitary" bacteria evade killing by antibiotics and neutrophils and are morphologically distinct from bacteria in IBCs. We conclude that bacteria with QIR-like properties may arise at early stages of infection, independent of IBC formation and rupture.

Abstract 126: HUB Organoids: bringing the 'patient in the lab' for preclinical and clinical development

Preclinical disease models are essential for the development of novel therapies and help better understand the molecular processes. In recent years, the groundbreaking technology to generate patient specific in vitro cultures based on adult stem-cell (ASC) organoids, has gained widespread interest for the development of new therapies and as a predictive diagnostic tool. ASC-derived organoids can be generated at high efficiency from both healthy and diseased tissue (resections as well as biopsies) including most carcinomas. These patient-derived cultures can be expanded for prolonged periods of time while maintaining many properties of the tissue they were derived from.

At Hubrecht Organoid Technology (HUB), we have created comprehensive ‘organoid living biobanks' from tumors of different origin like colon, lung, breast, pancreas and ovary. These biobanks have been characterized at the genetic and transcriptional level. These analyses have shown that our ‘organoid living biobanks' capture disease heterogeneity at the genetic and molecular level.

Because HUB Organoids can be expanded long term, drug screening is feasible in these models. HUB has developed procedures for (high-throughput) compound screening in organoids including small molecules and biologics. In this setting, HUB Organoids have been used to identify novel targets, identify lead compounds and stratify potential responders based on their genetic or molecular profile.

In addition, HUB Organoids can serve as a patient avatar in clinical development or diagnostics. In this setting, HUB Organoids could add a functional test for therapy response in a patient centered setting providing a unique tool for personalized medicine.

Citation Format: Jasper Mullenders, Annemarie Buijs, Lars-Eric Fielmich, Jasper Sluimer, Jane Sun, Robert G. Vries, Sylvia F. Boj. HUB Organoids: bringing the 'patient in the lab' for preclinical and clinical development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 126.

Abstract 2977: Organoid-T-cell co-cultures for preclinical testing of adoptive cell and cancer immunotherapy

Recent advances in cancer immunotherapy had a positive impact on the life expectancy of patients with a large range of clinical indications. With new treatment strategies and druggable targets being identified at an increasing pace, the number of patients eligible for cancer immunotherapy is expected to expand steadily. However, promising therapeutic developments face hurdles in translating preclinical findings into therapy. Challenges range from lack of confidence in animal cancer models, inter-tumor heterogeneity and the absence of cellular microenvironment. Hubrecht Organoid Technology (HUB) offers an innovative alternative, build on the discovery that adult stem cells proliferate and organize into three-dimensional organotypic structures when they are embedded into Matrigel. HUBOrganoids™ are generated from healthy and disease tissues and stored as “living” biobanks with high quality and reproducibility. HUB Organoids recapitulate complex characteristics of the original parental tissue, including molecular heterogeneity, and morphological and functional traits. HUB has developed organoid-T-cell co-culture systems that allow a physiologic representation of the complexity of interactions in the tumor microenvironment, which is important for evaluating the effects of novel therapies. HUB offers an innovative platform combining image-based analysis with flow cytometry to visualize and quantify T-cell-tumor interactions as well as measurements of T-cell cytotoxicity against tumor (and normal-matched) organoids for colorectal and several other cancers. Our platform offers a powerful strategy for the development and validation of cancer immunotherapy and may help to screen the efficacy of immune checkpoint blockade or bispecific antibodies. In addition, cancer organoid-T-cell co-culture may also predict the functionality of tumor-infiltrating lymphocytes (TIL) and chimeric antigen receptor (CAR)-engineered T cells. As such, our platform offers opportunities in preclinical development and could become a diagnostic tool to predict individual patient response to immunotherapy.

Citation Format: Pleun Hombrink, Soura Mardpour, Ewout Spaan, Jarmil Hanrath, Farzin Pourfarzad, Jasper Mullenders, Rene Overmeer, G.J Robert, Vries, F Sylvia, Boj. Organoid-T-cell co-cultures for preclinical testing of adoptive cell and cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2977.

Abstract LB-008: Patient derived organoids: Bringing the "patient in the lab" for pre-clinical and clinical development

Pre-clinical disease models are essential for the development of novel therapies and help better understand the molecular processes. In recent years, a novel groundbreaking technology to generate patient specific in vitro cultures based on adult stem-cell organoids, has gained widespread interest for the development of new therapies and as a predictive diagnostic tool. ASC-organoids can be generated at high efficiency from both healthy and diseased tissue (resections as well as biopsies) including most carcinomas. These patient derived cultures can be expanded for prolonged periods of time while maintaining many properties of the tissue they were derived from. At HUB, we have created comprehensive ‘living biobanks' from tumors of different origin like colon, lung, breast, pancreas and ovary. These biobanks have been characterized at the genetic and transcriptional level. These analyses have shown that our ‘living biobanks' capture disease heterogeneity at the genetic and molecular level. Because organoids can be expanded long term, drug screening is feasible in these models. HUB has developed procedures for (high-throughput) compound screening in organoids including small molecules and biologics. In this setting, organoids have been used to identify novel targets, identify lead compounds and stratify potential responders based on their genetic or molecular profile. Recent advances in the field of immuno-oncology have revolutionized the treatment for cancer patients. Despite of the improvements and due to the complex and highly regulated nature of the immune system, treatment does not have a similar effect on all tumors. We have created a co-culture model of tumor derived organoids and immune cells. In these co-cultures, the cytotoxic effect of the immune cell on the tumor can be measured in a reproducible and quantitative manner. Currently we are expanding existing co-culture models to incorporate different immune cells and organoid tumor types. In addition, organoids can serve as a patient avatar in clinical development or diagnostics. In this setting, organoids could add a functional test for therapy response in a patient centered setting providing a unique tool for personalized medicine.

Citation Format: Jasper Mullenders, Annemarie Buijs, Inge Van Maanen, Carol Piani, Soura Mardpour, Hans Clevers, Rob Vries, Sylvia Boj. Patient derived organoids: Bringing the "patient in the lab" for pre-clinical and clinical development [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr LB-008.

Protocol for Application, Standardization and Validation of the Forskolin-Induced Swelling Assay in Cystic Fibrosis Human Colon Organoids

This protocol describes the isolation, handling, culture of, and experiments with human colon stem cell organoids in the context of cystic fibrosis (CF). In human colon organoids, the function of cystic fibrosis transmembrane conductance regulator (CFTR) protein and its rescue by CFTR modulators can be quantified using the forskolin-induced swelling assay. Implementation procedures and validation experiments are described for six CF human colon organoid lines, and representative CFTR genotypes are tested for basal CFTR function and response to CFTR-modulating drugs. For complete details on the use and execution of this protocol, please refer to Dekkers et al (2016) and Berkers and van Mourik (2019).

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Rectal biopsies are used to efficiently establish human colon organoid cultures

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Human colon organoids can be cultured and biobanked for prolonged periods

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Human colon organoids can be used to measure function of the CFTR protein using FIS

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Reference CF organoid lines are available for validation of the FIS assay

CRISPR-Based Adenine Editors Correct Nonsense Mutations in a Cystic Fibrosis Organoid Biobank

Adenine base editing (ABE) enables enzymatic conversion from A-T into G-C base pairs. ABE holds promise for clinical application, as it does not depend on the introduction of double-strand breaks, contrary to conventional CRISPR/Cas9-mediated genome engineering. Here, we describe a cystic fibrosis (CF) intestinal organoid biobank, representing 664 patients, of which ~20% can theoretically be repaired by ABE. We apply SpCas9-ABE (PAM recognition sequence: NGG) and xCas9-ABE (PAM recognition sequence: NGN) on four selected CF organoid samples. Genetic and functional repair was obtained in all four cases, while whole-genome sequencing (WGS) of corrected lines of two patients did not detect off-target mutations. These observations exemplify the value of large, patient-derived organoid biobanks representing hereditary disease and indicate that ABE may be safely applied in human cells.

MED12 Regulates HSC-Specific Enhancers Independently of Mediator Kinase Activity to Control Hematopoiesis

Hematopoietic-specific transcription factors require coactivators to communicate with the general transcription machinery and establish transcriptional programs that maintain hematopoietic stem cell (HSC) self-renewal, promote differentiation, and prevent malignant transformation. Mediator is a large coactivator complex that bridges enhancer-localized transcription factors with promoters, but little is known about Mediator function in adult stem cell self-renewal and differentiation. We show that MED12, a member of the Mediator kinase module, is an essential regulator of HSC homeostasis, as in vivo deletion of Med12 causes rapid bone marrow aplasia leading to acute lethality. Deleting other members of the Mediator kinase module does not affect HSC function, suggesting kinase-independent roles of MED12. MED12 deletion destabilizes P300 binding at lineage-specific enhancers, resulting in H3K27Ac depletion, enhancer de-activation, and consequent loss of HSC stemness signatures. As MED12 mutations have been described recently in blood malignancies, alterations in MED12-dependent enhancer regulation may control both physiological and malignant hematopoiesis.

Cohesin loss alters adult hematopoietic stem cell homeostasis, leading to myeloproliferative neoplasms

The cohesin complex (consisting of Rad21, Smc1a, Smc3, and Stag2 proteins) is critically important for proper sister chromatid separation during mitosis. Mutations in the cohesin complex were recently identified in a variety of human malignancies including acute myeloid leukemia (AML). To address the potential tumor-suppressive function of cohesin in vivo, we generated a series of shRNA mouse models in which endogenous cohesin can be silenced inducibly. Notably, silencing of cohesin complex members did not have a deleterious effect on cell viability. Furthermore, knockdown of cohesin led to gain of replating capacity of mouse hematopoietic progenitor cells. However, cohesin silencing in vivo rapidly altered stem cells homeostasis and myelopoiesis. Likewise, we found widespread changes in chromatin accessibility and expression of genes involved in myelomonocytic maturation and differentiation. Finally, aged cohesin knockdown mice developed a clinical picture closely resembling myeloproliferative disorders/neoplasms (MPNs), including varying degrees of extramedullary hematopoiesis (myeloid metaplasia) and splenomegaly. Our results represent the first successful demonstration of a tumor suppressor function for the cohesin complex, while also confirming that cohesin mutations occur as an early event in leukemogenesis, facilitating the potential development of a myeloid malignancy.

TET1 is a tumor suppressor of hematopoietic malignancy

The methylcytosine dioxygenase TET1 ('ten-eleven translocation 1') is an important regulator of 5-hydroxymethylcytosine (5hmC) in embryonic stem cells. The diminished expression of TET proteins and loss of 5hmC in many tumors suggests a critical role for the maintenance of this epigenetic modification. Here we found that deletion of Tet1 promoted the development of B cell lymphoma in mice. TET1 was required for maintenance of the normal abundance and distribution of 5hmC, which prevented hypermethylation of DNA, and for regulation of the B cell lineage and of genes encoding molecules involved in chromosome maintenance and DNA repair. Whole-exome sequencing of TET1-deficient tumors revealed mutations frequently found in non-Hodgkin B cell lymphoma (B-NHL), in which TET1 was hypermethylated and transcriptionally silenced. Our findings provide in vivo evidence of a function for TET1 as a tumor suppressor of hematopoietic malignancy.

Mechanisms of epigenetic regulation of leukemia onset and progression

Over the past decade, it has become clear that both genetics and epigenetics play pivotal roles in cancer onset and progression. The importance of epigenetic regulation in proper maintenance of cellular state is highlighted by the frequent mutation of chromatin modulating factors across cancer subtypes. Identification of these mutations has created an interest in designing drugs that target enzymes involved in DNA methylation and posttranslational modification of histones. In this review, we discuss recurrent genetic alterations to epigenetic modulators in both myeloid and lymphoid leukemias. Furthermore, we review how these perturbations contribute to leukemogenesis and impact disease outcome and treatment efficacy. Finally, we discuss how the recent advances in our understanding of chromatin biology may impact treatment of leukemia.

Interleukin-1R-associated kinase 2 is a novel modulator of the transforming growth factor beta signaling cascade

The transforming growth factor beta (TGFbeta) pathway orchestrates an extensive transcriptional program that is important for many processes in the cell. For example, TGFbeta regulates cell cycle, migration, and epithelial-to-mesenchymal transition. The TGFbeta pathway has a dual role in cancer: it is involved in early-stage tumor suppression but also contributes to tumor progression by promoting invasion. To identify the novel genes involved in TGFbeta pathway signaling, we have performed a functional genetic loss-of-function screen. We screened a small interfering RNA library targeting 700 kinases and kinase-related genes in a TGFbeta-responsive reporter assay. Several genes were identified that upon knockdown could repress the reporter signal; among these are the two cellular receptors for TGFbeta. In addition to these two known components of the TGFbeta pathway, several genes were identified that were previously not linked to the TGFbeta signaling. Knockdown of one of these genes, the IRAK2 kinase, resulted not only in an impaired TGFbeta target gene response but also in a reduction of the nuclear accumulation and phosphorylation of SMAD2. In addition, suppression of interleukin-1R-associated kinase 2 expression led to a partial override of a TGFbeta-induced cell cycle arrest. Our data show that interleukin-1R-associated kinase 2 is a novel and critical component of TGFbeta signaling.

A large scale shRNA barcode screen identifies the circadian clock component ARNTL as putative regulator of the p53 tumor suppressor pathway

BACKGROUND

The p53 tumor suppressor gene is mutated in about half of human cancers, but the p53 pathway is thought to be functionally inactivated in the vast majority of cancer. Understanding how tumor cells can become insensitive to p53 activation is therefore of major importance. Using an RNAi-based genetic screen, we have identified three novel genes that regulate p53 function.

RESULTS

We have screened the NKI shRNA library targeting 8,000 human genes to identify modulators of p53 function. Using the shRNA barcode technique we were able to quickly identify active shRNA vectors from a complex mixture. Validation of the screening results indicates that the shRNA barcode technique can reliable identify active shRNA vectors from a complex pool. Using this approach we have identified three genes, ARNTL, RBCK1 and TNIP1, previously unknown to regulate p53 function. Importantly, ARNTL (BMAL1) is an established component of the circadian regulatory network. The latter finding adds to recent observations that link circadian rhythm to the cell cycle and cancer. We show that cells having suppressed ARNTL are unable to arrest upon p53 activation associated with an inability to activate the p53 target gene p21(CIP1).

CONCLUSIONS

We identified three new regulators of the p53 pathway through a functional genetic screen. The identification of the circadian core component ARNTL strengthens the link between circadian rhythm and cancer.

An shRNA barcode screen provides insight into cancer cell vulnerability to MDM2 inhibitors

The identification of the cellular targets of small molecules with anticancer activity is crucial to their further development as drug candidates. Here, we present the application of a large-scale RNA interference-based short hairpin RNA (shRNA) barcode screen to gain insight in the mechanism of action of nutlin-3 (1). Nutlin-3 is a small-molecule inhibitor of MDM2, which can activate the p53 pathway. Nutlin-3 shows strong antitumor effects in mice, with surprisingly few side effects on normal tissues. Aside from p53, we here identify 53BP1 as a critical mediator of nutlin-3-induced cytotoxicity. 53BP1 is part of a signaling network induced by DNA damage that is frequently activated in cancer but not in healthy tissues. Our results suggest that nutlin-3's tumor specificity may result from its ability to turn a cancer cell-specific property (activated DNA damage signaling) into a weakness that can be exploited therapeutically.

Involvement of MINK, a Ste20 Family Kinase, in Ras Oncogene-Induced Growth Arrest in Human Ovarian Surface Epithelial Cells

The ability of activated Ras to induce growth arrest of human ovarian surface epithelial (HOSE) cells via induction of the cyclin-dependent kinase inhibitor p21(WAF1/CIP1) has been used to screen for Ras pathway signaling components using a library of RNA interference (RNAi) vectors targeting the kinome. Two known Ras-regulated kinases were identified, phosphoinositide 3-kinase p110alpha and ribosomal protein S6 kinase p70(S6K1), plus the MAP kinase kinase kinase kinase MINK, which had not previously been implicated in Ras signaling. MINK is activated after Ras induction via a mechanism involving reactive oxygen species and mediates stimulation of the stress-activated protein kinase p38 MAPK downstream of the Raf/ERK pathway. p38 MAPK activation is essential for Ras-induced p21(WAF1/CIP1) upregulation and cell cycle arrest. MINK is thus a distal target of Ras signaling in the induction of a growth-arrested, senescent-like phenotype that may act to oppose oncogenic transformation in HOSE cells.

A genetic screen identifies PITX1 as a suppressor of RAS activity and tumorigenicity

Activating mutations of RAS frequently occur in subsets of human cancers, indicating that RAS activation is important for tumorigenesis. However, a large proportion of these cancers still retain wild-type RAS alleles, suggesting that either the RAS pathway is activated in a distinct manner or another pathway is deregulated. To uncover novel tumor-suppressor genes, we screened an RNA-interference library for knockdown constructs that transform human primary cells in the absence of ectopically introduced oncogenic RAS. Here we report the identification of PITX1, whose inhibition induces the RAS pathway and tumorigenicity. Interestingly, we observed low expression of PITX1 in prostate and bladder tumors and in colon cancer cell lines containing wild-type RAS. Restoration of PITX1 in the colon cancer cells inhibited tumorigenicity in a wild-type RAS-dependent manner. Finally, we identified RASAL1, a RAS-GTPase-activating protein, as a transcription target through which PITX1 affects RAS function. Thus, PITX1 suppresses tumorigenicity by downregulating the RAS pathway through RASAL1.

A large-scale RNAi screen in human cells identifies new components of the p53 pathway

RNA interference (RNAi) is a powerful new tool with which to perform loss-of-function genetic screens in lower organisms and can greatly facilitate the identification of components of cellular signalling pathways. In mammalian cells, such screens have been hampered by a lack of suitable tools that can be used on a large scale. We and others have recently developed expression vectors to direct the synthesis of short hairpin RNAs (shRNAs) that act as short interfering RNA (siRNA)-like molecules to stably suppress gene expression. Here we report the construction of a set of retroviral vectors encoding 23,742 distinct shRNAs, which target 7,914 different human genes for suppression. We use this RNAi library in human cells to identify one known and five new modulators of p53-dependent proliferation arrest. Suppression of these genes confers resistance to both p53-dependent and p19ARF-dependent proliferation arrest, and abolishes a DNA-damage-induced G1 cell-cycle arrest. Furthermore, we describe siRNA bar-code screens to rapidly identify individual siRNA vectors associated with a specific phenotype. These new tools will greatly facilitate large-scale loss-of-function genetic screens in mammalian cells.