ABSTRACT
Gastroenteropancreatic (GEP) neuroendocrine neoplasm (NEN) that consists of neuroendocrine tumor and neuroendocrine carcinoma (NEC) is a lethal but under-investigated disease owing to its rarity. To fill the scarcity of clinically relevant models of GEP-NEN, we here established 25 lines of NEN organoids and performed their comprehensive molecular characterization. GEP-NEN organoids recapitulated pathohistological and functional phenotypes of the original tumors. Whole-genome sequencing revealed frequent genetic alterations in TP53 and RB1 in GEP-NECs, and characteristic chromosome-wide loss of heterozygosity in GEP-NENs. Transcriptome analysis identified molecular subtypes that are distinguished by the expression of distinct transcription factors. GEP-NEN organoids gained independence from the stem cell niche irrespective of genetic mutations. Compound knockout of TP53 and RB1, together with overexpression of key transcription factors, conferred on the normal colonic epithelium phenotypes that are compatible with GEP-NEN biology. Altogether, our study not only provides genetic understanding of GEP-NEN, but also connects its genetics and biological phenotypes.
Subject(s)
Biological Specimen Banks , Neuroendocrine Tumors/pathology , Organoids/pathology , Animals , Chromosomes, Human/genetics , Genotype , Humans , Intercellular Signaling Peptides and Proteins/metabolism , Intestinal Neoplasms/genetics , Intestinal Neoplasms/pathology , Male , Mice , Models, Genetic , Mutation/genetics , Neuroendocrine Tumors/genetics , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , Phenotype , Stomach Neoplasms/genetics , Stomach Neoplasms/pathology , Transcriptome/genetics , Whole Genome SequencingABSTRACT
Recent sequencing analyses have shed light on heterogeneous patterns of genomic aberrations in human gastric cancers (GCs). To explore how individual genetic events translate into cancer phenotypes, we established a biological library consisting of genetically engineered gastric organoids carrying various GC mutations and 37 patient-derived organoid lines, including rare genomically stable GCs. Phenotype analyses of GC organoids revealed divergent genetic and epigenetic routes to gain Wnt and R-spondin niche independency. An unbiased phenotype-based genetic screening identified a significant association between CDH1/TP53 compound mutations and the R-spondin independency that was functionally validated by CRISPR-based knockout. Xenografting of GC organoids further established the feasibility of Wnt-targeting therapy for Wnt-dependent GCs. Our results collectively demonstrate that multifaceted genetic abnormalities render human GCs independent of the stem cell niche and highlight the validity of the genotype-phenotype screening strategy in gaining deeper understanding of human cancers.
Subject(s)
Adenocarcinoma/pathology , Organoids/pathology , Stomach Neoplasms/pathology , Stomach/pathology , Thrombospondins/metabolism , Wnt Proteins/metabolism , Adenocarcinoma/genetics , Adenocarcinoma/metabolism , Animals , Antigens, CD/genetics , Apoptosis , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Cadherins/genetics , Carcinogenesis , Cell Proliferation , Clustered Regularly Interspaced Short Palindromic Repeats , Humans , Male , Mice , Mice, Inbred NOD , Mice, SCID , Mutation , Organoids/metabolism , Stomach Neoplasms/genetics , Stomach Neoplasms/metabolism , Thrombospondins/genetics , Tumor Cells, Cultured , Tumor Suppressor Protein p53/genetics , Wnt Proteins/genetics , Xenograft Model Antitumor AssaysABSTRACT
Recent studies have documented frequent evolution of clones carrying common cancer mutations in apparently normal tissues, which are implicated in cancer development1-3. However, our knowledge is still missing with regard to what additional driver events take place in what order, before one or more of these clones in normal tissues ultimately evolve to cancer. Here, using phylogenetic analyses of multiple microdissected samples from both cancer and non-cancer lesions, we show unique evolutionary histories of breast cancers harbouring der(1;16), a common driver alteration found in roughly 20% of breast cancers. The approximate timing of early evolutionary events was estimated from the mutation rate measured in normal epithelial cells. In der(1;16)(+) cancers, the derivative chromosome was acquired from early puberty to late adolescence, followed by the emergence of a common ancestor by the patient's early 30s, from which both cancer and non-cancer clones evolved. Replacing the pre-existing mammary epithelium in the following years, these clones occupied a large area within the premenopausal breast tissues by the time of cancer diagnosis. Evolution of multiple independent cancer founders from the non-cancer ancestors was common, contributing to intratumour heterogeneity. The number of driver events did not correlate with histology, suggesting the role of local microenvironments and/or epigenetic driver events. A similar evolutionary pattern was also observed in another case evolving from an AKT1-mutated founder. Taken together, our findings provide new insight into how breast cancer evolves.
Subject(s)
Breast Neoplasms , Cell Lineage , Clone Cells , Evolution, Molecular , Mutagenesis , Mutation , Adolescent , Adult , Female , Humans , Young Adult , Breast Neoplasms/diagnosis , Breast Neoplasms/genetics , Breast Neoplasms/pathology , Cell Lineage/genetics , Clone Cells/metabolism , Clone Cells/pathology , Epigenesis, Genetic , Epithelial Cells/cytology , Epithelial Cells/metabolism , Epithelium/pathology , Microdissection , Mutation Rate , Premenopause , Tumor MicroenvironmentABSTRACT
Cancer relapse after chemotherapy remains a main cause of cancer-related death. Although the relapse is thought to result from the propagation of resident cancer stem cells1, a lack of experimental platforms that enable the prospective analysis of cancer stem cell dynamics with sufficient spatiotemporal resolution has hindered the testing of this hypothesis. Here we develop a live genetic lineage-tracing system that allows the longitudinal tracking of individual cells in xenotransplanted human colorectal cancer organoids, and identify LGR5+ cancer stem cells that exhibit a dormant behaviour in a chemo-naive state. Dormant LGR5+ cells are marked by the expression of p27, and intravital imaging provides direct evidence of the persistence of LGR5+p27+ cells during chemotherapy, followed by clonal expansion. Transcriptome analysis reveals that COL17A1-a cell-adhesion molecule that strengthens hemidesmosomes-is upregulated in dormant LGR5+p27+ cells. Organoids in which COL17A1 is knocked out lose the dormant LGR5+p27+ subpopulation and become sensitive to chemotherapy, which suggests that the cell-matrix interface has a role in the maintenance of dormancy. Chemotherapy disrupts COL17A1 and breaks the dormancy in LGR5+p27+ cells through FAK-YAP activation. Abrogation of YAP signalling prevents chemoresistant cells from exiting dormancy and delays the regrowth of tumours, highlighting the therapeutic potential of YAP inhibition in preventing cancer relapse. These results offer a viable therapeutic approach to overcome the refractoriness of human colorectal cancer to conventional chemotherapy.
Subject(s)
Colonic Neoplasms , Neoplastic Stem Cells , Autoantigens/metabolism , Cell Cycle Proteins/metabolism , Cell Lineage , Cell Proliferation , Cell Tracking , Colonic Neoplasms/drug therapy , Colonic Neoplasms/genetics , Colonic Neoplasms/pathology , Focal Adhesion Kinase 1/metabolism , Gene Expression Profiling , Heterografts , Humans , Neoplasm Recurrence, Local/pathology , Neoplastic Stem Cells/pathology , Non-Fibrillar Collagens/metabolism , Organoids/metabolism , Organoids/pathology , Receptors, G-Protein-Coupled/metabolism , Transcription Factors/metabolism , Collagen Type XVIIABSTRACT
The small intestine is the main organ for nutrient absorption, and its extensive resection leads to malabsorption and wasting conditions referred to as short bowel syndrome (SBS). Organoid technology enables an efficient expansion of intestinal epithelium tissue in vitro1, but reconstruction of the whole small intestine, including the complex lymphovascular system, has remained challenging2. Here we generate a functional small intestinalized colon (SIC) by replacing the native colonic epithelium with ileum-derived organoids. We first find that xenotransplanted human ileum organoids maintain their regional identity and form nascent villus structures in the mouse colon. In vitro culture of an organoid monolayer further reveals an essential role for luminal mechanistic flow in the formation of villi. We then develop a rat SIC model by repositioning the SIC at the ileocaecal junction, where the epithelium is exposed to a constant luminal stream of intestinal juice. This anatomical relocation provides the SIC with organ structures of the small intestine, including intact vasculature and innervation, villous structures, and the lacteal (a fat-absorbing lymphatic structure specific to the small intestine). The SIC has absorptive functions and markedly ameliorates intestinal failure in a rat model of SBS, whereas transplantation of colon organoids instead of ileum organoids invariably leads to mortality. These data provide a proof of principle for the use of intestinal organoids for regenerative purposes, and offer a feasible strategy for SBS treatment.
Subject(s)
Colon/cytology , Ileum/transplantation , Intestinal Mucosa/cytology , Organoids/transplantation , Regeneration , Regenerative Medicine/methods , Short Bowel Syndrome/therapy , Animals , Colon/blood supply , Colon/innervation , Colon/surgery , Disease Models, Animal , Heterografts , Humans , Ileum/cytology , Intestinal Mucosa/blood supply , Intestinal Mucosa/innervation , Intestinal Mucosa/surgery , Male , Organ Culture Techniques , Organoids/cytology , Rats , Rats, Inbred Lew , Short Bowel Syndrome/pathology , Short Bowel Syndrome/surgeryABSTRACT
With ageing, normal human tissues experience an expansion of somatic clones that carry cancer mutations1-7. However, whether such clonal expansion exists in the non-neoplastic intestine remains unknown. Here, using whole-exome sequencing data from 76 clonal human colon organoids, we identify a unique pattern of somatic mutagenesis in the inflamed epithelium of patients with ulcerative colitis. The affected epithelium accumulates somatic mutations in multiple genes that are related to IL-17 signalling-including NFKBIZ, ZC3H12A and PIGR, which are genes that are rarely affected in colon cancer. Targeted sequencing validates the pervasive spread of mutations that are related to IL-17 signalling. Unbiased CRISPR-based knockout screening in colon organoids reveals that the mutations confer resistance to the pro-apoptotic response that is induced by IL-17A. Some of these genetic mutations are known to exacerbate experimental colitis in mice8-11, and somatic mutagenesis in human colon epithelium may be causally linked to the inflammatory process. Our findings highlight a genetic landscape that adapts to a hostile microenvironment, and demonstrate its potential contribution to the pathogenesis of ulcerative colitis.
Subject(s)
Colitis, Ulcerative/genetics , Epithelium/metabolism , Interleukin-17/genetics , Mutation , Colitis, Ulcerative/metabolism , Humans , Interleukin-17/metabolism , Phenotype , Signal TransductionABSTRACT
Precision oncology presumes an accurate prediction of drug response on the basis of the molecular profile of tumors. However, the extent to which patient-derived tumor organoids recapitulate the response of in vivo tumors to a given drug remains obscure. To gain insights into the pharmacobiology of human colorectal cancer (CRC), we here created a robust drug screening platform for patient-derived colorectal organoids. Application of suspension culture increased organoid scalability, and a refinement of the culture condition enabled incorporation of normal and precursor organoids to high-throughput drug screening. Drug screening identified bromodomain and extra-terminal (BET) bromodomain protein inhibitor as a cancer-selective growth suppressor that targets genes aberrantly activated in CRC. A multi-omics analysis identified an association between checkpoint with forkhead and ring finger domaines (CHFR) silencing and paclitaxel sensitivity, which was further validated by gene engineering of organoids and in xenografts. Our findings highlight the utility of multiparametric validation in enhancing the biological and clinical fidelity of a drug screening system.
Subject(s)
Colorectal Neoplasms , Organoids , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Early Detection of Cancer , Epigenesis, Genetic , Humans , Organoids/pathology , Precision MedicineABSTRACT
BACKGROUND & AIMS: In the mouse intestinal epithelium, Lgr5+ stem cells are vulnerable to injury, owing to their predominantly cycling nature, and their progenies de-differentiate to replenish the stem cell pool. However, how human colonic stem cells behave in homeostasis and during regeneration remains unknown. METHODS: Transcriptional heterogeneity among colonic epithelial cells was analyzed by means of single-cell RNA sequencing analysis of human and mouse colonic epithelial cells. To trace the fate of human colonic stem or differentiated cells, we generated LGR5-tdTomato, LGR5-iCasase9-tdTomato, LGR5-split-Cre, and KRT20-ERCreER knock-in human colon organoids via genome engineering. p27+ dormant cells were further visualized with the p27-mVenus reporter. To analyze the dynamics of human colonic stem cells in vivo, we orthotopically xenotransplanted fluorescence-labeled human colon organoids into immune-deficient mice. The cell cycle dynamics in xenograft cells were evaluated using 5-ethynyl-2'-deoxyuridine pulse-chase analysis. The clonogenic capacity of slow-cycling human stem cells or differentiated cells was analyzed in the context of homeostasis, LGR5 ablation, and 5-fluorouracil-induced mucosal injury. RESULTS: Single-cell RNA sequencing analysis illuminated the presence of nondividing LGR5+ stem cells in the human colon. Visualization and lineage tracing of slow-cycling LGR5+p27+ cells and orthotopic xenotransplantation validated their homeostatic lineage-forming capability in vivo, which was augmented by 5-FU-induced mucosal damage. Transforming growth factor-ß signaling regulated the quiescent state of LGR5+ cells. Despite the plasticity of differentiated KRT20+ cells, they did not display clonal growth after 5-FU-induced injury, suggesting that occupation of the niche environment by LGR5+p27+ cells prevented neighboring differentiated cells from de-differentiating. CONCLUSIONS: Our results highlight the quiescent nature of human LGR5+ colonic stem cells and their contribution to post-injury regeneration.
Subject(s)
Receptors, G-Protein-Coupled , Stem Cells , Humans , Mice , Animals , Receptors, G-Protein-Coupled/genetics , Receptors, G-Protein-Coupled/metabolism , Stem Cells/metabolism , Colon/metabolism , Intestinal Mucosa/metabolism , Fluorouracil , Transforming Growth Factors/metabolismABSTRACT
The cancer stem cell (CSC) theory highlights a self-renewing subpopulation of cancer cells that fuels tumour growth. The existence of human CSCs is mainly supported by xenotransplantation of prospectively isolated cells, but their clonal dynamics and plasticity remain unclear. Here, we show that human LGR5+ colorectal cancer cells serve as CSCs in growing cancer tissues. Lineage-tracing experiments with a tamoxifen-inducible Cre knock-in allele of LGR5 reveal the self-renewal and differentiation capacity of LGR5+ tumour cells. Selective ablation of LGR5+ CSCs in LGR5-iCaspase9 knock-in organoids leads to tumour regression, followed by tumour regrowth driven by re-emerging LGR5+ CSCs. KRT20 knock-in reporter marks differentiated cancer cells that constantly diminish in tumour tissues, while reverting to LGR5+ CSCs and contributing to tumour regrowth after LGR5+ CSC ablation. We also show that combined chemotherapy potentiates targeting of LGR5+ CSCs. These data provide insights into the plasticity of CSCs and their potential as a therapeutic target in human colorectal cancer.
Subject(s)
Cell Tracking , Colonic Neoplasms/drug therapy , Colonic Neoplasms/pathology , Molecular Targeted Therapy , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/pathology , Receptors, G-Protein-Coupled/metabolism , Animals , Cell Differentiation , Cell Lineage , Cell Proliferation , Cell Self Renewal , Colonic Neoplasms/genetics , Colonic Neoplasms/metabolism , Gene Knock-In Techniques , Humans , Keratin-20/genetics , Keratin-20/metabolism , Male , Mice , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/transplantation , Organoids/metabolism , Organoids/pathology , Organoids/transplantation , Receptors, G-Protein-Coupled/genetics , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND AND AIMS: Diffuse-type gastric cancer (GC) is currently subdivided into signet-ring cell carcinoma (SRCC) and non-SRCC, referred to as poorly cohesive carcinoma not otherwise specified (PCC-NOS). Although these subtypes are considered to be independent, they often coexist in the same tumors, raising a question of whether they clonally differ or not. To tackle this question, we established an experimental platform for human diffuse GC that enables accurate modeling of histologic subtypes. METHODS: Seven patient-derived diffuse GC organoid lines were established, characterized by histopathologic analysis, in situ hybridization, and gene expression analysis. For genetic modeling of diffuse GC, we knocked out CDH1 and/or TP53 in human normal gastric organoids. Green fluorescent protein-labeled GC organoids were xenotransplanted into immune-deficient mice for in vivo assessment. RESULTS: PCC-NOS organoids transformed into SRCC-like structures on removal of Wnt and R-spondin from the culture medium. This morphologic change paralleled downregulation of Wnt-target and gastric stem cell genes, including LGR5, and elevation of differentiation markers, such as KRT20 and MUCs. The association between Wnt target gene expression and histologic subtypes was confirmed in 3 patient-derived GC tissues. In vivo, single clone-derived organoids formed tumors that comprised 2 distinct histologic compartments, each corresponding to SRCC and PCC-NOS. The transition from PCC-NOS to SRCC histology reflected the abundance of surrounding R-spondin-expressing fibroblasts. CONCLUSIONS: SRCC and PCC-NOS were clonally identical, and their morphology was regulated by extracellular Wnt and R-spondin expression. Our results decoded how genetic mutations and the tumor environment shape pathohistologic and biologic phenotypes in human diffuse GCs.
Subject(s)
Carcinoma, Signet Ring Cell/parasitology , Gastric Mucosa/pathology , Stomach Neoplasms/pathology , Wnt Signaling Pathway , Aged , Animals , Antigens, CD/genetics , Antigens, CD/metabolism , Cadherins/genetics , Cadherins/metabolism , Carcinoma, Signet Ring Cell/genetics , Female , Gastric Mucosa/cytology , Gene Knockout Techniques , Humans , Male , Mice , Middle Aged , Organoids/pathology , Primary Cell Culture , RNA-Seq , Stomach Neoplasms/genetics , Thrombospondins , Tumor Cells, Cultured , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Exome Sequencing , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND & AIMS: Traditional serrated adenomas (TSAs) are rare colorectal polyps with unique histologic features. Fusions in R-spondin genes have been found in TSAs, but it is not clear whether these are sufficient for TSA development, due to the lack of a chromosome engineering platform for human tissues. We studied the effects of fusions in R-spondin genes and other genetic alterations found in TSA using CRISPR-Cas9-mediated chromosome and genetic modification of human colonic organoids. METHODS: We introduced chromosome rearrangements that involve R-spondin genes into human colonic organoids, with or without disruption of TP53, using CRISPR-Cas9 (chromosome-engineered organoids). We then knocked a mutation into BRAF encoding the V600E substitution and overexpressed the GREM1 transgene; the organoids were transplanted into colons of NOG mice and growth of xenograft tumors was measured. Colon tissues were collected and analyzed by immunohistochemistry or in situ hybridization. We also established 2 patient-derived TSA organoid lines and characterized their genetic features and phenotypes. We inserted a bicistronic cassette expressing a dimerizer-inducible suicide gene and fluorescent marker downstream of the LGR5 gene in the chromosome-engineered organoids; addition of the dimerizer eradicates LGR5+ cells. Some tumor-bearing mice were given intraperitoneal injections of the dimerizer to remove LGR5-expressing cells. RESULTS: Chromosome engineering of organoids required disruption of TP53 or culture in medium containing IGF1 and FGF2. In colons of mice, organoids that expressed BRAFV600E and fusions in R-spondin genes formed flat serrated lesions. Patient-derived TSA organoids grew independent of exogenous R-spondin, and 1 line grew independent of Noggin. Organoids that overexpressed GREM1, in addition to BRAFV600E and fusions in R-spondin genes, formed polypoid tumors in mice that had histologic features similar to TSAs. Xenograft tumors persisted after loss of LGR5-expressing cells. CONCLUSIONS: We demonstrated efficient chromosomal engineering of human normal colon organoids. We introduced genetic and chromosome alterations into human colon organoids found in human TSAs; tumors grown from these organoids in mice had histopathology features of TSAs. This model might be used to study progression of human colorectal tumors with RSPO fusion gene and GREM1 overexpression.
Subject(s)
Adenoma/genetics , Colonic Neoplasms/genetics , Intercellular Signaling Peptides and Proteins/genetics , Organoids/pathology , Thrombospondins/genetics , Adenoma/pathology , Animals , CRISPR-Cas Systems , Colonic Neoplasms/pathology , Eukaryotic Initiation Factor-3/genetics , Gene Fusion , Genetic Engineering , Humans , Male , Mice , Models, Biological , Neoplasm Transplantation , Proto-Oncogene Proteins B-raf/genetics , Receptor-Like Protein Tyrosine Phosphatases, Class 2/genetics , Receptors, G-Protein-Coupled/genetics , Tumor Suppressor Protein p53/genetics , Wnt Signaling PathwayABSTRACT
The enzyme involved in the increase in glutamic acid content in chicken meat during cooking was identified and characterized. Chicken homogenate produced significantly more free glutamic acid and exhibited higher glutamyl p-nitroanilide (Glu-pNA) hydrolyzing activity than beef when heat cooked. Amino acid sequencing revealed the presence of aspartyl aminopeptidase (DNPEP) in chicken meat. Using RT-PCR, DNPEP gene expression was detected in chicken breast and thigh muscles, liver, and small intestine, together with various other peptidase genes. Full-length DNPEP cDNA was cloned, and recombinant chicken DNPEP (cDNPEP) was expressed in Escherichia coli. cDNPEP showed five-fold higher activity against Glu-pNA than against aspartyl-pNA, which represents a different substrate specificity than observed for recombinant bovine DNPEP (bDNPEP). The Km values of both DNPEPs with Glu p-NA substrates indicated a higher affinity of cDNPEP for glutamyl residues. This unique substrate specificity of cDNPEP contributes to efficient glutamic acid production in chickens.
ABSTRACT
Riboflavin-binding protein (RBP) is a glycophosphoprotein found in hen eggs. We previously identified the extraordinary characteristic of RBP in reducing bitterness. For a more detailed study on the mode of action and industrial application of this characteristic, we investigated the microbial production of recombinant RBP (rRBP). We constructed a chicken RBP gene expression vector by inserting the RBP cDNA in pNCMO2, the Escherichia coli-Brevibacillus choshinensis shuttle vector. B. choshinensis HPD31 transformants produced 0.8g/l of processed and unglycosylated RBP in a soluble form in the culture supernatant. However, the expressed RBP was partially dimerized and monomeric RBP was purified by two step anion-exchange and gel-filtration chromatographies. The purified rRBP elicited bitterness reduction against quinine and caffeine, although it largely lost its riboflavin-binding ability. These results indicated that glycosylation and riboflavin-binding ability are not essential for the bitterness reduction of RBP. In addition, we assessed the usefulness of the Brevibacillus system for the expression and secretion of RBP as a new type of bitterness inhibitor.
Subject(s)
Biochemistry/methods , Brevibacterium/metabolism , Extracellular Space/metabolism , Membrane Transport Proteins/biosynthesis , Membrane Transport Proteins/pharmacology , Taste/drug effects , Animals , Cell Culture Techniques , Chickens , Membrane Transport Proteins/isolation & purification , Protein Binding , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Riboflavin/metabolism , Time FactorsABSTRACT
BACKGROUND: Sex steroid hormone receptors are classified into three classes of receptors: estrogen receptors (ER) α and ß, androgen receptor (AR), and progesterone receptor (PR). They belong to the nuclear receptor superfamily and activate their downstream genes in a ligand-dependent manner. Since sex steroid hormones are involved in a wide variety of physiological processes and cancer development, synthetic chemical substances that exhibit sex steroid hormone activities have been applied as pharmaceuticals and consumed in large amounts worldwide. They are potentially hazardous contaminants as endocrine disruptors in the environment because they may induce inappropriate gene expression mediated by sex steroid hormone receptors in vivo. RESULTS: To develop simple reporter gene assays with enhanced sensitivity for the detection of sex steroid hormones, we newly established mutant yeast strains lacking the CWP and PDR genes encoding cell wall mannoproteins and plasma membrane drug efflux pumps, respectively, and expressing human ERα, ERß, AR, and PR. Reporter gene assays with mutant yeast strains responded to endogenous and synthetic ligands more strongly than those with wild-type strains. Sex steroid hormone activities in some pharmaceutical oral tablets and human urine were also detectable in these yeast assays. CONCLUSIONS: Yeast reporter gene assay systems for all six steroid hormone receptors, including previously established glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) assay yeasts, are now available. Environmental endocrine disrupters with steroid hormone activity will be qualitatively detectable by simple and easy procedures. The yeast-based reporter gene assay will be valuable as a primary screening tool to detect and evaluate steroid hormone activities in various test samples. Our assay system will strongly support the detection of agonists, antagonists, and inverse agonists of steroid hormone receptors in the field of novel drug discovery and assessments of environmental pollutants.
ABSTRACT
Intestinal epithelial homeostasis is maintained by adult intestinal stem cells, which, alongside Paneth cells, appear after birth in the neonatal period. We aimed to identify regulators of neonatal intestinal epithelial development by testing a small library of epigenetic modifier inhibitors in Paneth cell-skewed organoid cultures. We found that lysine-specific demethylase 1A (Kdm1a/Lsd1) is absolutely required for Paneth cell differentiation. Lsd1-deficient crypts, devoid of Paneth cells, are still able to form organoids without a requirement of exogenous or endogenous Wnt. Mechanistically, we find that LSD1 enzymatically represses genes that are normally expressed only in fetal and neonatal epithelium. This gene profile is similar to what is seen in repairing epithelium, and we find that Lsd1-deficient epithelium has superior regenerative capacities after irradiation injury. In summary, we found an important regulator of neonatal intestinal development and identified a druggable target to reprogram intestinal epithelium toward a reparative state.
Subject(s)
Intestinal Mucosa , Paneth Cells , Cell Differentiation/genetics , Histone Demethylases/genetics , Humans , Infant, Newborn , OrganoidsABSTRACT
The version of this paper originally published shows incorrect units for two plasmid concentrations. In the "Reagent Setup" section, the instructions for sgRNA-Cas9 plasmid should read "Adjust the concentration of each plasmid to 1 µg µl-1," rather than "to 1 µg ml-1." Similarly, all concentrations in the tables in Steps 49A, 49C, and 49D should be in µg µl-1 instead of µg ml-1. Please note that these units have not been corrected in the PDF and HTML versions of the protocol available online.
ABSTRACT
Fermented food contains numerous peptides derived from material proteins. Bitter peptides formed during the fermentation process are responsible for the bitter taste of fermented food. We investigated whether human bitter receptors (hTAS2Rs) recognize bitterness of peptides with a heterologous expression system. HEK293 cells expressing hTAS2R1, hTAS2R4, hTAS2R14, and hTAS2R16 responded to bitter casein digests. Among those cells, the hTAS2R1-expressing cell was most strongly activated by the synthesized bitter peptides Gly-Phe and Gly-Leu, and none of the cells was activated by the non-bitter dipeptide Gly-Gly. The results showed that these bitter peptides, as well as many other bitter compounds, activate hTAS2Rs, suggesting that humans utilize these hTAS2Rs to recognize and perceive the structure and bitterness of peptides.
Subject(s)
Kidney/drug effects , Kidney/metabolism , Peptides/administration & dosage , Receptors, G-Protein-Coupled/metabolism , Taste/physiology , Cell Line , Humans , Taste/drug effectsABSTRACT
Cellular diversity that shapes tissue architecture and function is governed by multiple niche signals. Nonetheless, maintaining cellular diversity in human intestinal organoids has been challenging. Based on niche ligands present in the natural stem cell milieu, we establish a refined organoid culture condition for intestinal epithelia that allows human intestinal organoids to concurrently undergo multi-differentiation and self-renewal. High-throughput screening reveals that the combination of insulin-like growth factor 1 (IGF-1) and fibroblast growth factor 2 (FGF-2) enhances the clonogenic capacity and CRISPR-genome engineering efficiency of human intestinal stem cells. The combination equally enables long-term culture of a range of intestinal organoids, including rat small intestinal organoids. Droplet-based single-cell RNA sequencing further illustrates the conservation of the native cellular diversity in human small intestinal organoids cultured with the refined condition. The modified culture protocol outperforms the conventional method and offers a viable strategy for modeling human intestinal tissues and diseases in an in vivo relevant context.
Subject(s)
Cell Culture Techniques , Cell Self Renewal , Intestines/cytology , Organoids/cytology , Stem Cell Niche , Animals , Cells, Cultured , Humans , Male , Rats , Rats, Inbred LewABSTRACT
Genetic lineage tracing has revealed that Lgr5+ murine colon stem cells (CoSCs) rapidly proliferate at the crypt bottom. However, the spatiotemporal dynamics of human CoSCs in vivo have remained experimentally intractable. Here we established an orthotopic xenograft system for normal human colon organoids, enabling stable reconstruction of the human colon epithelium in vivo. Xenografted organoids were prone to displacement by the remaining murine crypts, and this could be overcome by complete removal of the mouse epithelium. Xenografted organoids formed crypt structures distinctively different from surrounding mouse crypts, reflecting their human origin. Lineage tracing using CRISPR-Cas9 to engineer an LGR5-CreER knockin allele demonstrated self-renewal and multipotency of LGR5+ CoSCs. In contrast to the rapidly cycling properties of mouse Lgr5+ CoSCs, human LGR5+ CoSCs were slow-cycling in vivo. This organoid-based orthotopic xenograft model enables investigation of the functional behaviors of human CoSCs in vivo, with potential therapeutic applications in regenerative medicine.
Subject(s)
Colon/physiology , Intestinal Mucosa/physiology , Regeneration/physiology , Animals , Humans , Male , Mice , Organoids/metabolism , Receptors, G-Protein-Coupled/metabolism , Transplantation, HeterologousABSTRACT
Despite recent efforts to dissect the inter-tumor heterogeneity of pancreatic ductal adenocarcinoma (PDAC) by determining prognosis-predictive gene expression signatures for specific subtypes, their functional differences remain elusive. Here, we established a pancreatic tumor organoid library encompassing 39 patient-derived PDACs and identified 3 functional subtypes based on their stem cell niche factor dependencies on Wnt and R-spondin. A Wnt-non-producing subtype required Wnt from cancer-associated fibroblasts, whereas a Wnt-producing subtype autonomously secreted Wnt ligands and an R-spondin-independent subtype grew in the absence of Wnt and R-spondin. Transcriptome analysis of PDAC organoids revealed gene-expression signatures that associated Wnt niche subtypes with GATA6-dependent gene expression subtypes, which were functionally supported by genetic perturbation of GATA6. Furthermore, CRISPR-Cas9-based genome editing of PDAC driver genes (KRAS, CDKN2A, SMAD4, and TP53) demonstrated non-genetic acquisition of Wnt niche independence during pancreas tumorigenesis. Collectively, our results reveal functional heterogeneity of Wnt niche independency in PDAC that is non-genetically formed through tumor progression.