Murine Colonic Organoid Culture System and Downstream Assay Applications

Involvement of Intestinal Epithelium Aryl Hydrocarbon Receptor Expression and 3, 3'-Diindolylmethane in Colonic Tertiary Lymphoid Tissue Formation

Tertiary lymphoid tissues (TLTs) are adaptive immune structures that develop during chronic inflammation and may worsen or lessen disease outcomes in a context-specific manner. Immune cell activity governing TLT formation in the intestines is dependent on immune cell aryl hydrocarbon receptor (AhR) activation. Homeostatic immune cell activity in the intestines is further dependent on ligand activation of AhR in intestinal epithelial cells (IECs), yet whether AhR activation and signaling in IECs influences the formation of TLTs in the presence of dietary AhR ligands is not known. To this end, we used IEC-specific AhR deletion coupled with a mouse model of dextran sodium sulfate (DSS)-induced colitis to understand how dietary AhR ligand 3, 3'-diindolylmethane (DIM) influenced TLT formation. DIM consumption increased the size of TLTs and decreased T-cell aggregation to TLT sites in an IEC-specific manner. In DSS-exposed female mice, DIM consumption increased the expression of genes implicated in TLT formation (Interleukin-22, Il-22; CXC motif chemokine ligand 13, CXCL13) in an IEC AhR-specific manner. Conversely, in female mice without DSS exposure, DIM significantly reduced the expression of Il-22 or CXCL13 in iAhRKO mice, but this effect was not observed in WT animals. Our findings suggest that DIM affects the immunological landscape of TLT formation during DSS-induced colitis in a manner contingent on AhR expression in IECs and biological sex. Further investigations into specific immune cell activity, IEC-specific AhR signaling pathways, and dietary AhR ligand-mediated effects on TLT formation are warranted.

ZEB1-mediated fibroblast polarization controls inflammation and sensitivity to immunotherapy in colorectal cancer

The EMT-transcription factor ZEB1 is heterogeneously expressed in tumor cells and in cancer-associated fibroblasts (CAFs) in colorectal cancer (CRC). While ZEB1 in tumor cells regulates metastasis and therapy resistance, its role in CAFs is largely unknown. Combining fibroblast-specific Zeb1 deletion with immunocompetent mouse models of CRC, we observe that inflammation-driven tumorigenesis is accelerated, whereas invasion and metastasis in sporadic cancers are reduced. Single-cell transcriptomics, histological characterization, and in vitro modeling reveal a crucial role of ZEB1 in CAF polarization, promoting myofibroblastic features by restricting inflammatory activation. Zeb1 deficiency impairs collagen deposition and CAF barrier function but increases NFκB-mediated cytokine production, jointly promoting lymphocyte recruitment and immune checkpoint activation. Strikingly, the Zeb1-deficient CAF repertoire sensitizes to immune checkpoint inhibition, offering a therapeutic opportunity of targeting ZEB1 in CAFs and its usage as a prognostic biomarker. Collectively, we demonstrate that ZEB1-dependent plasticity of CAFs suppresses anti-tumor immunity and promotes metastasis.

Aryl hydrocarbon receptor activity in intestinal epithelial cells in the formation of colonic tertiary lymphoid tissues

After birth, the development of secondary lymphoid tissues (SLTs) in the colon is dependent on the expression of the aryl hydrocarbon receptor (AhR) in immune cells as a response to the availability of AhR ligands. However, little is known about how AhR activity from intestinal epithelial cells (IECs) may influence the development of tertiary lymphoid tissues (TLTs). As organized structures that develop at sites of inflammation or infection during adulthood, TLTs serve as localized centers of adaptive immune responses, and their presence has been associated with the resolution of inflammation and tumorigenesis in the colon. Here, we investigated the effect of the conditional loss of AhR activity in IECs in the formation and immune cell composition of TLTs in a model of acute inflammation. In females, loss of AhR activity in IECs reduced the formation of TLTs without significantly changing disease outcomes or immune cell composition within TLTs. In males lacking AhR expression in IECs, increased disease activity index, lower expression of functional-IEC genes, increased number of TLTs, increased T-cell density, and lower B- to T-cell ratio were observed. These findings may represent an unfavorable prognosis when exposed to dextran sodium sulfate (DSS)-induced epithelial damage compared with females. Sex and loss of IEC AhR also resulted in changes in microbial populations in the gut. Collectively, these data suggest that the formation of TLTs in the colon is influenced by sex and AhR expression in IECs.NEW & NOTEWORTHY This is the first research of its kind to demonstrate a clear connection between biological sex and the development of tertiary lymphoid tissues (TLT) in the colon. In addition, the research finds that in a preclinical model of inflammatory bowel disease, the expression of the aryl hydrocarbon receptor (AhR) influences the development of these structures in a sex-specific manner.

A Three-Step Protocol to Differentiate iPSC into Colon Organoids

Organoids, three-dimensional, stem cell-based structures that mimic the cellular and functional architecture of tissues, have emerged as an innovative in vitro tool. They offer highly efficient models for studying both embryonic development and disease progression processes. Colon organoids can also be generated from biopsies obtained during a colonoscopy. However, the invasive nature of biopsy collection poses practical challenges and introduces biases when studying patients who are already afflicted. Therefore, the use of iPSC-derived colon organoids can be considered a more practical approach for researchers and patients alike. Numerous protocols have been published for generating colon organoids from iPSCs. While most of these protocols share a common developmental process, some are labor-intensive or require additional equipment. Taking these considerations into account, we present a cost-effective and straightforward yet functionally robust colon organoid protocol: (1) definitive endoderm differentiation, (2) hindgut endoderm differentiation, and (3) maturation of colon spheroids into mature organoids.

Mutant APC reshapes Wnt signaling plasma membrane nanodomains by altering cholesterol levels via oncogenic β-catenin

Although the role of the Wnt pathway in colon carcinogenesis has been described previously, it has been recently demonstrated that Wnt signaling originates from highly dynamic nano-assemblies at the plasma membrane. However, little is known regarding the role of oncogenic APC in reshaping Wnt nanodomains. This is noteworthy, because oncogenic APC does not act autonomously and requires activation of Wnt effectors upstream of APC to drive aberrant Wnt signaling. Here, we demonstrate the role of oncogenic APC in increasing plasma membrane free cholesterol and rigidity, thereby modulating Wnt signaling hubs. This results in an overactivation of Wnt signaling in the colon. Finally, using the Drosophila sterol auxotroph model, we demonstrate the unique ability of exogenous free cholesterol to disrupt plasma membrane homeostasis and drive Wnt signaling in a wildtype APC background. Collectively, these findings provide a link between oncogenic APC, loss of plasma membrane homeostasis and CRC development.

Three-Dimensional Culture of Murine Colonic Crypts to Study Intestinal Stem Cell Function Ex Vivo

The intestinal epithelium regenerates every 5-7 days, and is controlled by the intestinal epithelial stem cell (IESC) population located at the bottom of the crypt region. IESCs include active stem cells, which self-renew and differentiate into various epithelial cell types, and quiescent stem cells, which serve as the reserve stem cells in the case of injury. Regeneration of the intestinal epithelium is controlled by the self-renewing and differentiating capabilities of these active IESCs. In addition, the balance of the crypt stem cell population and maintenance of the stem cell niche are essential for intestinal regeneration. Organoid culture is an important and attractive approach to studying proteins, signaling molecules, and environmental cues that regulate stem cell survival and functions. This model is less expensive, less time-consuming, and more manipulatable than animal models. Organoids also mimic the tissue microenvironment, providing in vivo relevance. The present protocol describes the isolation of colonic crypts, embedding these isolated crypt cells into a three-dimensional gel matrix system and culturing crypt cells to form colonic organoids capable of self-organization, proliferation, self-renewal, and differentiation. This model allows one to manipulate the environment-knocking out specific proteins such as claudin-7, activating/deactivating signaling pathways, etc.-to study how these effects influence the functioning of colonic stem cells. Specifically, the role of tight junction protein claudin-7 in colonic stem cell function was examined. Claudin-7 is vital for maintaining intestinal homeostasis and barrier function and integrity. Knockout of claudin-7 in mice induces an inflammatory bowel disease-like phenotype exhibiting intestinal inflammation, epithelial hyperplasia, weight loss, mucosal ulcerations, epithelial cell sloughing, and adenomas. Previously, it was reported that claudin-7 is required for intestinal epithelial stem cell functions in the small intestine. In this protocol, a colonic organoid culture system is established to study the role of claudin-7 in the large intestine.

Application of Organoids in Carcinogenesis Modeling and Tumor Vaccination

Organoids well recapitulate organ-specific functions from their tissue of origin and remain fundamental aspects of organogenesis. Organoids are widely applied in biomedical research, drug discovery, and regenerative medicine. There are various cultivated organoid systems induced by adult stem cells and pluripotent stem cells, or directly derived from primary tissues. Researchers have drawn inspiration by combination of organoid technology and tissue engineering to produce organoids with more physiological relevance and suitable for translational medicine. This review describes the value of applying organoids for tumorigenesis modeling and tumor vaccination. We summarize the application of organoids in tumor precision medicine. Extant challenges that need to be conquered to make this technology be more feasible and precise are discussed.

Loss of aryl hydrocarbon receptor suppresses the response of colonic epithelial cells to IL22 signaling by upregulating SOCS3

IL22 signaling plays an important role in maintaining gastrointestinal epithelial barrier function, cell proliferation, and protection of intestinal stem cells from genotoxicants. Emerging studies indicate that the aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, promotes production of IL22 in gut immune cells. However, it remains to be determined if AhR signaling can also affect the responsiveness of colonic epithelial cells to IL22. Here, we show that IL22 treatment induces the phosphorylation of STAT3, inhibits colonic organoid growth, and promotes colonic cell proliferation in vivo. Notably, intestinal cell-specific AhR knockout (KO) reduces responsiveness to IL22 and compromises DNA damage response after exposure to carcinogen, in part due to the enhancement of suppressor of cytokine signaling 3 (SOCS3) expression. Deletion of SOCS3 increases levels of pSTAT3 in AhR KO organoids, and phenocopies the effects of IL22 treatment on wild-type (WT) organoid growth. In addition, pSTAT3 levels are inversely associated with increased azoxymethane/dextran sulfate sodium (AOM/DSS)-induced colon tumorigenesis in AhR KO mice. These findings indicate that AhR function is required for optimal IL22 signaling in colonic epithelial cells and provide rationale for targeting AhR as a means of reducing colon cancer risk.NEW & NOTEWORTHY AhR is a key transcription factor controlling expression of IL22 in gut immune cells. In this study, we show for the first time that AhR signaling also regulates IL22 response in colonic epithelial cells by modulating SOCS3 expression.

A β-Catenin-TCF-Sensitive Locus Control Region Mediates GUCY2C Ligand Loss in Colorectal Cancer

BACKGROUND & AIMS

Sporadic colorectal cancers arise from initiating mutations in APC, producing oncogenic β-catenin/TCF-dependent transcriptional reprogramming. Similarly, the tumor suppressor axis regulated by the intestinal epithelial receptor GUCY2C is among the earliest pathways silenced in tumorigenesis. Retention of the receptor, but loss of its paracrine ligands, guanylin and uroguanylin, is an evolutionarily conserved feature of colorectal tumors, arising in the earliest dysplastic lesions. Here, we examined a mechanism of GUCY2C ligand transcriptional silencing by β-catenin/TCF signaling.

METHODS

We performed RNA sequencing analysis of 4 unique conditional human colon cancer cell models of β-catenin/TCF signaling to map the core Wnt-transcriptional program. We then performed a comparative analysis of orthogonal approaches, including luciferase reporters, chromatin immunoprecipitation sequencing, CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats) knockout, and CRISPR epigenome editing, which were cross-validated with human tissue chromatin immunoprecipitation sequencing datasets, to identify functional gene enhancers mediating GUCY2C ligand loss.

RESULTS

RNA sequencing analyses reveal the GUCY2C hormones as 2 of the most sensitive targets of β-catenin/TCF signaling, reflecting transcriptional repression. The GUCY2C hormones share an insulated genomic locus containing a novel locus control region upstream of the guanylin promoter that mediates the coordinated silencing of both genes. Targeting this region with CRISPR epigenome editing reconstituted GUCY2C ligand expression, overcoming gene inactivation by mutant β-catenin/TCF signaling.

CONCLUSIONS

These studies reveal DNA elements regulating corepression of GUCY2C ligand transcription by β-catenin/TCF signaling, reflecting a novel pathophysiological step in tumorigenesis. They offer unique genomic strategies that could reestablish hormone expression in the context of canonical oncogenic mutations to reconstitute the GUCY2C axis and oppose transformation.

Role of the Aryl Hydrocarbon Receptor (AhR) in Mediating the Effects of Coffee in the Colon

SCOPE

This study investigates the mechanism of action and functional effects of coffee extracts in colonic cells, on intestinal stem cell growth, and inhibition of dextran sodium sulfate (DSS)-induced intestinal barrier damage in mice.

METHODS AND RESULTS

Aqueous coffee extracts induced Ah receptor (AhR) -responsive CYP1A1, CYP1B1, and UGT1A1 gene expression in colon-derived Caco2 and YAMC cells. Tissue-specific AhR knockout (AhR^f/f x Lgr5-GFP-CreERT2 x Villin-Cre), wild-type (Lgr5-CreERT2 x Villin-Cre) mice are sources of stem cell enriched organoids and both coffee extracts and norharman, an AhR-active component of these extracts inhibited stem cell growth. Coffee extracts also inhibit DSS-induced damage to intestinal barrier function and DSS-induced mucosal inflammatory genes such as IL-6 and TGF-β1 in wild-type (AhR^+/+ ) but not AhR^-/- mice. In contrast, coffee does not exhibit protective effects in intestinal-specific AhR knockout mice. Coffee extracts also enhanced overall formation of AhR-active microbial metabolites.

CONCLUSIONS

In colon-derived cells and in the mouse intestine, coffee induced several AhR-dependent responses including gene expression, inhibition of intestinal stem cell-enriched organoid growth, and inhibition of DSS-induced intestinal barrier damage. We conclude that the anti-inflammatory effects of coffee in the intestine are due, in part, to activation of AhR signaling.

SHP2 regulates the development of intestinal epithelium by modifying OSTERIX+ crypt stem cell self-renewal and proliferation

The protein tyrosine phosphatase SHP2, encoded by PTPN11, is ubiquitously expressed and essential for the development and/or maintenance of multiple tissues and organs. SHP2 is involved in gastrointestinal (GI) epithelium development and homeostasis, but the underlying mechanisms remain elusive. While studying SHP2's role in skeletal development, we made osteoblast-specific SHP2 deficient mice using Osterix (Osx)-Cre as a driver to excise Ptpn11 floxed alleles. Phenotypic characterization of these SHP2 mutants unexpectedly revealed a critical role of SHP2 in GI biology. Mice lacking SHP2 in Osx⁺ cells developed a fatal GI pathology with dramatic villus hypoplasia. OSTERIX, an OB-specific zinc finger-containing transcription factor is for the first time found to be expressed in GI crypt cells, and SHP2 expression in the crypt Osx+ cells is critical for self-renewal and proliferation. Further, immunostaining revealed the colocalization of OSTERIX with OLFM4 and LGR5, two bona fide GI stem cell markers, at the crypt cells. Furthermore, OSTERIX expression is found to be associated with GI malignancies. Knockdown of SHP2 expression had no apparent influence on the relative numbers of enterocytes, goblet cells or Paneth cells. Given SHP2's key regulatory role in OB differentiation, our studies suggest that OSTERIX and SHP2 are indispensable for gut homeostasis, analogous to SOX9's dual role as a master regulator of cartilage and an important regulator of crypt stem cell biology. Our findings also provide a foundation for new avenues of inquiry into GI stem cell biology and of OSTERIX's therapeutic and diagnostic potential.

Loss of aryl hydrocarbon receptor potentiates FoxM1 signaling to enhance self-renewal of colonic stem and progenitor cells

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor that senses xenobiotics, diet, and gut microbial-derived metabolites, is increasingly recognized as a key regulator of intestinal biology. However, its effects on the function of colonic stem and progenitor cells remain largely unexplored. Here, we observed that inducible deletion of AhR in Lgr5⁺ stem cells increases the percentage of colonic stem cells and enhances organoid initiating capacity and growth of sorted stem and progenitor cells, while AhR activation has the opposite effect. Moreover, intestinal-specific AhR knockout increases basal stem cell and crypt injury-induced cell proliferation and promotes colon tumorigenesis in a preclinical colitis-associated tumor model by upregulating FoxM1 signaling. Mechanistically, AhR transcriptionally suppresses FoxM1 expression. Activation of AhR in human organoids recapitulates phenotypes observed in mice, such as reduction in the percentage of colonic stem cells, promotion of stem cell differentiation, and attenuation of FoxM1 signaling. These findings indicate that the AhR-FoxM1 axis, at least in part, mediates colonic stem/progenitor cell behavior.

Age-related taste cell generation in circumvallate papillae organoids via regulation of multiple signaling pathways

Sense of taste is central to evaluate food before digestion. Taste stem cells undergo constant differentiation throughout the life. However, the mechanism underlying the generation of taste receptor cells is still not clear. Here, we cultured taste organoids from either Lgr5+ or Lgr5-cells, and found the preferential generation of Car4+ and Gustducin + taste receptor cells in organoids derived from Lgr5+ cells in circumvallate, foliate or fungiform papillae. Taste organoids derived from Lgr5+ cells in circumvallate papillae of neonatal mice showed stronger capacity to generate taste receptor cells compared to the organoids from Lgr5+ cells of the adult circumvallate papillae. Massive transcriptional differences were found in multiple signaling pathways including taste transduction between organoids derived from circumvallate papillae of adult and neonatal mice. Inhibiting the Notch signaling pathway by LY411575 enhanced taste receptor cell generation in organoids from circumvallate papillae and modulated multiple signaling pathways. Thus, we concluded that receptor cell generation in taste organoids was age-related and regulated via multiple signaling pathways.

Effects of high-fat diet and intestinal aryl hydrocarbon receptor deletion on colon carcinogenesis

Consumption of a high-fat diet has been associated with an increased risk of developing colorectal cancer (CRC). However, the effects of the interaction between dietary fat content and the aryl hydrocarbon receptor (AhR) on colorectal carcinogenesis remain unclear. Mainly known for its role in xenobiotic metabolism, AhR has been identified as an important regulator for maintaining intestinal epithelial homeostasis. Although previous research using whole body AhR knockout mice has revealed an increased incidence of colon and cecal tumors, the unique role of AhR activity in intestinal epithelial cells (IECs) and modifying effects of fat content in the diet at different stages of sporadic CRC development are yet to be elucidated. In the present study, we have examined the effects of a high-fat diet on IEC-specific AhR knockout mice in a model of sporadic CRC. Although loss of AhR activity in IECs significantly induced the development of premalignant lesions, in a separate experiment, no significant changes in colon mass incidence were observed. Moreover, consumption of a high-fat diet promoted cell proliferation in crypts at the premalignant colon cancer lesion stage and colon mass multiplicity as well as β-catenin expression and nuclear localization in actively proliferating cells in colon masses. Our data demonstrate the modifying effects of high-fat diet and AhR deletion in IECs on tumor initiation and progression.NEW & NOTEWORTHY Through the use of an intestinal-specific aryl hydrocarbon receptor (AhR) knockout mouse model, this study demonstrates that the expression of AhR in intestinal epithelial cells is required to reduce the formation of premalignant colon cancer lesions. Furthermore, consumption of a high-fat diet and the loss of AhR in intestinal epithelial cells influences the development of colorectal cancer at various stages.

AdipoRon Attenuates Wnt Signaling by Reducing Cholesterol-Dependent Plasma Membrane Rigidity

The increasing prevalence of adult and adolescent obesity and its associated risk of colorectal cancer reinforces the urgent need to elucidate the underlying mechanisms contributing to the promotion of colon cancer in obese individuals. Adiponectin is an adipose tissue-derived adipokine, whose levels are reduced during obesity. Both epidemiological and preclinical data indicate that adiponectin suppresses colon tumorigenesis. We have previously demonstrated that both adiponectin and AdipoRon, a small-molecule adiponectin receptor agonist, suppress colon cancer risk in part by reducing the number of Lgr5+ stem cells in mouse colonic organoids. However, the mechanism by which the adiponectin signaling pathway attenuates colon cancer risk remains to be addressed. Here, we have hypothesized that adiponectin signaling supports colonic stem cell maintenance through modulation of the biophysical properties of the plasma membrane (PM). Specifically, we investigated the effects of adiponectin receptor activation by AdipoRon on the biophysical perturbations linked to the attenuation of Wnt-driven signaling and cell proliferation as determined by LEF luciferase reporter assay and colonic organoid proliferation, respectively. Using physicochemical sensitive dyes, Di-4-ANEPPDHQ and C-laurdan, we demonstrated that AdipoRon decreased the rigidity of the colonic cell PM. The decrease in membrane rigidity was associated with a reduction in PM free cholesterol levels and the intracellular accumulation of free cholesterol in lysosomes. These results suggest that adiponectin signaling plays a role in modulating cellular cholesterol homeostasis, PM biophysical properties, and Wnt-driven signaling. These findings are noteworthy because they may in part explain how obesity drives colon cancer progression.

A novel morphometry system automatically assessing the growth and regeneration of intestinal organoids

As compared with 2D cell line cultures, 3D intestinal organoids are better at maximally recapitulating the physiological features of stem cells in vivo. However, the complex 3D structure is an obstacle which must be objectively and automatically evaluated to assess colony growth and regeneration. Meanwhile, no internal standard currently exists for evaluating the size of heterogeneities in organoids or defining those regenerating colonies. Herein, we developed a simple morphometry system to image MTT-stained organoids. The growth curve of organoids can be automatically generated based upon analyzing the integrated optical density using software. Referencing the definition standards of in vivo regenerating crypts, the perimeters of crypts cultured 24 h after seeding were selected as an "Organoid Unit" to further evaluate colony survival rate and colony size heterogeneities after exposure to varying doses of irradiation. Moreover, the morphometry-based quantification data collected confirmed other findings associated with radiation sensitizing effects of ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related protein (ATR) inhibitor and the radiation protective effect of IL-22. In summary, the novel organoid morphometry system combined with a new internal reference is a practical means for standardizing assessment of growth, survival and regeneration of intestinal organoid colonies. This method has promise to facilitate drug screens in intestinal and other organoid systems.

Adenylyl cyclase 6 is involved in the hyposecretory status of experimental colitis

One of the cardinal symptoms of intestinal inflammation is diarrhea. Acute intestinal inflammation is associated with inhibition of ion absorption and increased secretion, along with fluid leakage due to epithelial injury and changes in permeability. However, in the chronic situation, a downregulation of both absorptive and secretory transport has been reported. We investigated how experimental colitis reduces cAMP levels in intestinal epithelial cells through modulation of adenylyl cyclases (AC). Primary colonic epithelial cells obtained from rats with trinitrobenzenesulfonic acid colitis and non-colitic controls were analyzed for AC expression by RT-qPCR and Western blot, following a preliminary microarray analysis. AC6 and AC5 were found to be expressed in colonocytes, and downregulated by inflammation, with the former exhibiting considerably higher mRNA levels in both cases. To test the hypothesis that inflammatory cytokines may account for this effect, Caco 2 cells were treated with IL-1β, TNF-α, or IFN-γ. All three cytokines inhibited forskolin evoked short-circuit currents in Ussing chambers and lowered intracellular cAMP, but failed to alter AC6 mRNA levels. AC5/AC6 expression was however inhibited in mouse jejunal organoids treated with IFN-γ and TNF-α, but not IL-1β. Gene knockdown of AC6 resulted in a significant decrease of ion secretion in T84 cells. We conclude that the disturbances in ion secretion observed in rat TNBS colitis are associated with low intracellular levels of cAMP in the epithelium, which may be explained in part by the downregulation of AC5/AC6 expression by proinflammatory cytokines.

Patient-derived organoid models help define personalized management of gastrointestinal cancer

BACKGROUND

The prognosis of patients with different gastrointestinal cancers varies widely. Despite advances in treatment strategies, such as extensive resections and the addition of new drugs to chemotherapy regimens, conventional treatment strategies have failed to improve survival for many tumours. Although promising, the clinical application of molecularly guided personalized treatment has proven to be challenging. This narrative review focuses on the personalization of cancer therapy using patient-derived three-dimensional 'organoid' models.

METHODS

A PubMed search was conducted to identify relevant articles. An overview of the literature and published protocols is presented, and the implications of these models for patients with cancer, surgeons and oncologists are explained.

RESULTS

Organoid culture methods have been established for healthy and diseased tissues from oesophagus, stomach, intestine, pancreas, bile duct and liver. Because organoids can be generated with high efficiency and speed from fine-needle aspirations, biopsies or resection specimens, they can serve as a personal cancer model. Personalized treatment could become a more standard practice by using these cell cultures for extensive molecular diagnosis and drug screening. Drug sensitivity assays can give a clinically actionable sensitivity profile of a patient's tumour. However, the predictive capability of organoid drug screening has not been evaluated in prospective clinical trials.

CONCLUSION

High-throughput drug screening on organoids, combined with next-generation sequencing, proteomic analysis and other state-of-the-art molecular diagnostic methods, can shape cancer treatment to become more effective with fewer side-effects.