Mouse and human urothelial cancer organoids Mullenders, Jasper; de Jongh, Evelien; Brousali, Anneta ...
Proceedings of the National Academy of Sciences - PNAS,
03/2019, Letnik:
116, Številka:
10
Journal Article
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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.
Effective predictive biomarkers are needed to enable personalized medicine and increase treatment efficacy and survival for cancer patients, thereby reducing toxic side effects and treatment costs. ...Patient-derived organoids (PDOs) enable individualized tumour response testing. Since 2018, 17 publications have examined PDOs as a potential predictive biomarker in the treatment of cancer patients. We review and provide a pooled analysis of the results regarding the use of PDOs in individualized tumour response testing, focusing on evidence for analytical validity, clinical validity and clinical utility. We identify future perspectives to accelerate the implementation of PDOs as a predictive biomarker in the treatment of cancer patients.
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.
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•664 patients and 154 CFTR mutations represented in an organoid biobank•Adenine base editors enable efficient repair of nonsense mutations in CFTR•xCas9 increases the target scope of CFTR repair in our biobank•Adenine base editors cause no detectable off-target effects during repair
Here, we show the generation of an extensive cystic fibrosis patient-derived intestinal organoid biobank. We use this biobank to study gene correction by adenine base editors and show genetic repair of four selected nonsense mutations in CFTR without any genome-wide off-target effects on canonical and non-canonical PAMs.
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.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
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.
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.
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•MED12 is required for hematopoietic stem cell function in a cell-autonomous manner•Depleting other members of the Mediator kinase module does not affect HSC survival•MED12 deletion leads to H3K27Ac loss at enhancers of key HSC genes, such as c-Kit•MED12 cooperates with P300 at enhancers of essential hematopoietic genes
Aranda-Orgilles et al. show in vivo a cell-autonomous requirement of MED12 in the maintenance of hematopoietic stem cell function independent of CYCLIN C/CDK8. MED12 cooperates with P300 to preserve enhancer activity, and loss of MED12 causes H3K27Ac depletion at enhancers of essential HSC genes and failure of hematopoietic-specific transcriptional programs.
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.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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•Human colon organoids can be cultured and biobanked for prolonged periods•Human colon organoids can be used to measure function of the CFTR protein using FIS•Reference CF organoid lines are available for validation of the FIS assay
Human colon organoids are used to measure the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein and its rescue by CFTR modulators through the forskolin-induced swelling assay. This protocol describes the isolation, culture of, and experiments with human colon stem cell organoids for studying cystic fibrosis.
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.
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.
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).
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.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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