Patient‐derived tumour xenografts and tumour organoids have become important preclinical model systems for cancer research. Both models maintain key features from their parental tumours, such as ...genetic and phenotypic heterogeneity, which allows them to be used for a wide spectrum of applications. In contrast to patient‐derived xenografts, organoids can be established and expanded with high efficiency from primary patient material. On the other hand, xenografts retain tumour–stroma interactions, which are known to contribute to tumorigenesis. In this review, we discuss recent advances in patient‐derived tumour xenograft and tumour organoid model systems and compare their promises and challenges as preclinical models in cancer research.
This review discusses recent advances in the use of patient‐derived tumour xenografts and patient‐derived tumour organoid models in fundamental and translational cancer research.
The intestinal stem cell Barker, Nick; van de Wetering, Marc; Clevers, Hans
Genes & development,
07/2008, Letnik:
22, Številka:
14
Journal Article
Recenzirano
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The epithelium of the adult mammalian intestine is in a constant dialog with its underlying mesenchyme to direct progenitor proliferation, lineage commitment, terminal differentiation, and, ...ultimately, cell death. The epithelium is shaped into spatially distinct compartments that are dedicated to each of these events. While the intestinal epithelium represents the most vigorously renewing adult tissue in mammals, the stem cells that fuel this self-renewal process have been identified only recently. The unique epithelial anatomy makes the intestinal crypt one of the most accessible models for the study of adult stem cell biology. This review attempts to provide a comprehensive overview of four decades of research on crypt stem cells.
The concept that tumors are maintained by dedicated stem cells, the so-called cancer stem cell hypothesis, has attracted great interest but remains controversial. Studying mouse models, we provide ...direct, functional evidence for the presence of stem cell activity within primary intestinal adenomas, a precursor to intestinal cancer. By "lineage retracing" using the multicolor Cre-reporter R26R-Confetti, we demonstrate that the crypt stem cell marker Lgr5 (leucine-rich repeat—containing heterotrimeric guanine nucleotide—binding protein—coupled receptor 5) also marks a subpopulation of adenoma cells that fuel the growth of established intestinal adenomas. These Lgr5 + cells, which represent about 5 to 10% of the cells in the adenomas, generate additional Lgr5 + cells as well as all other adenoma cell types. The Lgr5 + cells are intermingled with Paneth cells near the adenoma base, a pattern reminiscent of the architecture of the normal crypt niche.
Colorectal cancer (CRC) organoids can be derived from almost all CRC patients and therefore capture the genetic diversity of this disease. We assembled a panel of CRC organoids carrying either ...wild-type or mutant RAS, as well as normal organoids and tumor organoids with a CRISPR-introduced oncogenic
mutation. Using this panel, we evaluated RAS pathway inhibitors and drug combinations that are currently in clinical trial for RAS mutant cancers. Presence of mutant RAS correlated strongly with resistance to these targeted therapies. This was observed in tumorigenic as well as in normal organoids. Moreover, dual inhibition of the EGFR-MEK-ERK pathway in RAS mutant organoids induced a transient cell-cycle arrest rather than cell death. In vivo drug response of xenotransplanted RAS mutant organoids confirmed this growth arrest upon pan-HER/MEK combination therapy. Altogether, our studies demonstrate the potential of patient-derived CRC organoid libraries in evaluating inhibitors and drug combinations in a preclinical setting.
Cycling intestinal Lgr5⁺ stem cells are intermingled with their terminally differentiated Paneth cell daughters at crypt bottoms. Paneth cells provide multiple secreted (e.g., Wnt, EGF) as well as ...surface-bound (Notch ligand) niche signals. Here we show that ablation of Paneth cells in mice, using a diphtheria toxin receptor gene inserted into the P-lysozyme locus, does not affect the maintenance of Lgr5⁺ stem cells. Flow cytometry, single-cell sequencing, and histological analysis showed that the ablated Paneth cells are replaced by enteroendocrine and tuft cells. As these cells physically occupy Paneth cell positions between Lgr5 stem cells, they serve as an alternative source of Notch signals, which are essential for Lgr5⁺ stem cell maintenance. Our combined in vivo results underscore the adaptive flexibility of the intestine in maintaining normal tissue homeostasis.
Proliferation of the self-renewing epithelium of the gastric corpus occurs almost exclusively in the isthmus of the glands, from where cells migrate bidirectionally toward pit and base. The isthmus ...is therefore generally viewed as the stem cell zone. We find that the stem cell marker Troy is expressed at the gland base by a small subpopulation of fully differentiated chief cells. By lineage tracing with a Troy-eGFP-ires-CreERT2 allele, single marked chief cells are shown to generate entirely labeled gastric units over periods of months. This phenomenon accelerates upon tissue damage. Troy+ chief cells can be cultured to generate long-lived gastric organoids. Troy marks a specific subset of chief cells that display plasticity in that they are capable of replenishing entire gastric units, essentially serving as quiescent “reserve” stem cells. These observations challenge the notion that stem cell hierarchies represent a “one-way street.”
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•A subset of quiescent, differentiated chief cells express Troy•Troy+ chief cells can generate all differentiated lineages of the gastric epithelium•Troy+ chief cells act as “reserve” stem cells upon challenge of tissue homeostasis•Troy+ chief cells can initiate long-term in vitro cultures
Gastric chief cells expressing the marker Troy, although mature and differentiated, can re-enter the cell cycle and ultimately produce all cell lineages of the gastric epithelium, suggesting that they act as reserve stem cells.
Stem cells generate rapidly dividing transit-amplifying cells that have lost the capacity for self-renewal but cycle for a number of times until they exit the cell cycle and undergo terminal ...differentiation. We know very little of the type of signals that trigger the earliest steps of stem cell differentiation and mediate a stem cell to transit-amplifying cell transition. We show that in normal intestinal epithelium, endoplasmic reticulum (ER) stress and activity of the unfolded protein response (UPR) are induced at the transition from stem cell to transit-amplifying cell. Induction of ER stress causes loss of stemness in a Perk-eIF2α-dependent manner. Inhibition of Perk-eIF2α signaling results in stem cell accumulation in organoid culture of primary intestinal epithelium. Our findings show that the UPR plays an important role in the regulation of intestinal epithelial stem cell differentiation.
Despite the enormous replication potential of the human liver, there are currently no culture systems available that sustain hepatocyte replication and/or function in vitro. We have shown previously ...that single mouse Lgr5+ liver stem cells can be expanded as epithelial organoids in vitro and can be differentiated into functional hepatocytes in vitro and in vivo. We now describe conditions allowing long-term expansion of adult bile duct-derived bipotent progenitor cells from human liver. The expanded cells are highly stable at the chromosome and structural level, while single base changes occur at very low rates. The cells can readily be converted into functional hepatocytes in vitro and upon transplantation in vivo. Organoids from α1-antitrypsin deficiency and Alagille syndrome patients mirror the in vivo pathology. Clonal long-term expansion of primary adult liver stem cells opens up experimental avenues for disease modeling, toxicology studies, regenerative medicine, and gene therapy.
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•Establishment of a long-term human liver organoid culture•Human liver stem cells retain genetic stability after long-term expansion•Liver organoid cultures differentiate to functional hepatocytes in vitro and in vivo•Organoids derived from patients with genetic disorders model liver disease in vitro
A culture system that allows long-term expansion of human liver can be used to model and study various human diseases.
In Rspondin-based 3D cultures, Lgr5 stem cells from multiple organs form ever-expanding epithelial organoids that retain their tissue identity. We report the establishment of tumor organoid cultures ...from 20 consecutive colorectal carcinoma (CRC) patients. For most, organoids were also generated from adjacent normal tissue. Organoids closely recapitulate several properties of the original tumor. The spectrum of genetic changes within the “living biobank” agrees well with previous large-scale mutational analyses of CRC. Gene expression analysis indicates that the major CRC molecular subtypes are represented. Tumor organoids are amenable to high-throughput drug screens allowing detection of gene-drug associations. As an example, a single organoid culture was exquisitely sensitive to Wnt secretion (porcupine) inhibitors and carried a mutation in the negative Wnt feedback regulator RNF43, rather than in APC. Organoid technology may fill the gap between cancer genetics and patient trials, complement cell-line- and xenograft-based drug studies, and allow personalized therapy design.
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•Tumor and normal organoids were derived from colorectal carcinoma patients•Tumor organoids recapitulate somatic copy number and mutation spectra found in CRC•Organoids are amenable to high-throughput drug screening•Patient-derived organoids allow personalized therapy design
3D organoid cultures derived from healthy and tumor tissue from colorectal cancer patients are used for a high throughput drug screen to identify gene-drug associations that may facilitate personalized therapy.
The spread of cancer cells from primary tumors to regional lymph nodes is often associated with reduced survival. One prevailing model to explain this association posits that fatal, distant ...metastases are seeded by lymph node metastases. This view provides a mechanistic basis for the TNM staging system and is the rationale for surgical resection of tumor-draining lymph nodes. Here we examine the evolutionary relationship between primary tumor, lymph node, and distant metastases in human colorectal cancer. Studying 213 archival biopsy samples from 17 patients, we used somatic variants in hypermutable DNA regions to reconstruct high-confidence phylogenetic trees. We found that in 65% of cases, lymphatic and distant metastases arose from independent subclones in the primary tumor, whereas in 35% of cases they shared common subclonal origin. Therefore, two different lineage relationships between lymphatic and distant metastases exist in colorectal cancer.
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