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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. LGR5 + cells in human colorectal cancer tissue xenografted into mice act as cancer stem cells, and differentiated cancer cells can revert to cancer stem cells and express LGR5 after ablation of existing LGR5 + cells. Probing the plasticity of cancer stem cells Cancer stem cells are thought to maintain tumour growth by self-renewal but their clonal dynamics and plasticity in humans are not well understood. Mariko Shimokava et al . study the role of Lgr5 + cancer stem cells in patient-derived organoids that are transplanted into mice to monitor tumour growth. Through lineage tracing, they find that tumour growth is fuelled by Lgr5 + cells, which either self-renew or differentiate into KRT20 + cells. Unexpectedly, ablation of Lgr5 + cells only leads to temporary tumour regression and tumour growth resumes driven by KRT20 + cells that exhibit compensatory proliferation and conversion to Lgr5 + cells. They also find that targeting tumours with an anti-EGFR antibody that upregulates Lgr5 acts in synergy with Lgr5 + cell ablation to block tumour growth. These findings shed new light on cell plasticity within a hierarchical cancer stem cell model and suggest new therapeutic strategies.

Genome editing applied to human intestinal organoids enables the study of the functional effects of mutations recurrent in human tumors. Human colorectal tumors bear recurrent mutations in genes encoding proteins operative in the WNT, MAPK, TGF-β, TP53 and PI3K pathways 1 , 2 . Although these pathways influence intestinal stem cell niche signaling 3 , 4 , 5 , the extent to which mutations in these pathways contribute to human colorectal carcinogenesis remains unclear. Here we use the CRISPR-Cas9 genome-editing system 6 , 7 to introduce multiple such mutations into organoids derived from normal human intestinal epithelium. By modulating the culture conditions to mimic that of the intestinal niche, we selected isogenic organoids harboring mutations in the tumor suppressor genes APC , SMAD4 and TP53 , and in the oncogenes KRAS and/or PIK3CA. Organoids engineered to express all five mutations grew independently of niche factors in vitro , and they formed tumors after implantation under the kidney subcapsule in mice. Although they formed micrometastases containing dormant tumor-initiating cells after injection into the spleen of mice, they failed to colonize in the liver. In contrast, engineered organoids derived from chromosome-instable human adenomas formed macrometastatic colonies. These results suggest that 'driver' pathway mutations enable stem cell maintenance in the hostile tumor microenvironment, but that additional molecular lesions are required for invasive behavior.

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 vitro 1 , but reconstruction of the whole small intestine, including the complex lymphovascular system, has remained challenging 2 . 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. In a rat model of short bowel syndrome, transplantation of small intestinal organoids into the colon partially restores intestinal function and improves survival—a proof of principle that organoid transplantation might have therapeutic benefit.

With ageing, normal human tissues experience an expansion of somatic clones that carry cancer mutations 1 – 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 mice 8 – 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. Whole-exome sequencing of colon organoids derived from patients with ulcerative colitis identifies somatic mutations in components of the IL-17 signalling pathway, which may confer a growth advantage to cells under inflammatory conditions.

In 2020, Olympus Medical Systems Corporation introduced the Texture and Color Enhancement Imaging (TXI) as a new image-enhanced endoscopy. This study aimed to evaluate the visibility of neoplasms and mucosal atrophy in the upper gastrointestinal tract through TXI. We evaluated 72 and 60 images of 12 gastric neoplasms and 20 gastric atrophic/nonatrophic mucosa, respectively. The visibility of gastric mucosal atrophy and gastric neoplasm was assessed by six endoscopists using a previously reported visibility scale (1 = poor to 4 = excellent). Color differences between gastric mucosal atrophy and nonatrophic mucosa and between gastric neoplasm and adjacent areas were assessed using the International Commission on Illumination L*a*b* color space system. The visibility of mucosal atrophy and gastric neoplasm was significantly improved in TXI mode 1 compared with that in white-light imaging (WLI) (visibility score: 3.8 ± 0.5 vs. 2.8 ± 0.9, p  < 0.01 for mucosal atrophy; visibility score: 2.8 ± 1.0 vs. 2.0 ± 0.9, p  < 0.01 for gastric neoplasm). Regarding gastric atrophic and nonatrophic mucosae, TXI mode 1 had a significantly greater color difference than WLI (color differences: 14.2 ± 8.0 vs. 8.7 ± 4.2, respectively, p  < 0.01). TXI may be a useful observation modality in the endoscopic screening of the upper gastrointestinal tract.

BackgroundThis multicenter prospective study (UMIN000019958) aimed to evaluate the usefulness of serum leucin-rich alpha-2 glycoprotein (LRG) levels in monitoring disease activity in inflammatory bowel disease (IBD).MethodsPatients with moderate-to-severe IBD initiated on adalimumab therapy were enrolled herein. Serum LRG, C-reactive protein (CRP), and fecal calprotectin (fCal) levels were measured at week 0, 12, 24, and 52. Colonoscopy was performed at week 0, 12, and 52 for ulcerative colitis (UC), and at week 0, 24, and 52 for Crohn’s disease (CD). Endoscopic activity was assessed using the Simple Endoscopic Score for Crohn’s Disease (SES-CD) for CD and the Mayo endoscopic subscore (MES) for UC.ResultsA total of 81 patients was enrolled. Serum LRG levels decreased along with improvements in clinical and endoscopic outcomes upon adalimumab treatment (27.4 ± 12.6 μg/ml at week 0, 15.5 ± 7.7 μg/ml at week 12, 15.7 ± 9.6 μg/ml at week 24, and 14.5 ± 6.8 μg/ml at week 52), being correlated with endoscopic activity at each time point (SES-CD: r = 0.391 at week 0, r = 0.563 at week 24, r = 0.697 at week 52; MES: r = 0.534 at week 0, r = 0.429 at week 12, r = 0.335 at week 52). Endoscopic activity better correlated with LRG compared to CRP and fCal on pooled analysis at all time points (SES-CD: LRG: r = 0.636, CRP: r = 0.402, fCal: r = 0.435; MES: LRG: r = 0.568, CRP: 0.389, fCal: r = 0.426).ConclusionsSerum LRG is a useful biomarker of endoscopic activity both in CD and UC during the adalimumab treatment.

N-glycosylation of glycoproteins, a major post-translational modification, plays a crucial role in various biological phenomena. In central nervous systems, N-glycosylation is thought to be associated with differentiation and regeneration; however, the state and role of N-glycosylation in neuronal differentiation remain unclear. Here, we conducted sequential LC/MS/MS analyses of tryptic digest, enriched glycopeptides, and deglycosylated peptides of proteins derived from human-induced pluripotent stem cells (iPSCs) and iPSC-derived neuronal cells, which were used as a model of neuronal differentiation. We demonstrate that the production profiles of many glycoproteins and their glycoforms were altered during neuronal differentiation. Particularly, the levels of glycoproteins modified with an N-glycan, consisting of five N -acetylhexosamines, three hexoses, and a fucose (HN5H3F), increased in dopaminergic neuron-rich cells (DAs). The N-glycan was deduced to be a fucosylated and bisected biantennary glycan based on product ion spectra. Interestingly, the HN5H3F-modified proteins were predicted to be functionally involved in neural cell adhesion, axon guidance, and the semaphorin-plexin signaling pathway, and protein modifications were site-selective and DA-selective regardless of protein production levels. Our integrated method for glycoproteome analysis and resultant profiles of glycoproteins and their glycoforms provide valuable information for further understanding the role of N-glycosylation in neuronal differentiation and neural regeneration.

Matcha tea powder is believed to have various physiological benefits; however, its detailed mechanism of action has been poorly understood. Here, we investigated whether the mental state of mice, due to social isolation stress, affects the antidepressant-like effect of Matcha tea powder by using the tail suspension test. Oral administration of Matcha tea powder reduced the duration of immobility in the stress-susceptible C57BL/6J strain, but not in BALB/c strain. In C57BL/6J mice, SCH23390, a dopamine D1 receptor blocker, prevented Matcha tea powder from exerting its antidepressant-like effect. Matcha tea powder also increased the number of c-Fos-positive cells in the prefrontal cortex (PFC) region and the nucleus accumbens (NAc) region in C57BL/6J mice, but not in BALB/c mice. In contrast, Matcha tea powder did not change the number of c-Fos-positive cells in the ventral tegmental area (VTA) region. Notably, C57BL/6J mice with a shorter immobility time had a higher number of c-Fos-positive cells in the PFC, NAc, and VTA regions. However, no such correlation was observed in the stress-tolerant BALB/c mice. These results suggest that Matcha tea powder exerts an antidepressant-like effect through the activation of the dopaminergic system including the PFC-NAc-VTA circuit and that mental states are important factors affecting the physiological benefits of Matcha tea powder.

Although EGFR tyrosine kinase inhibitors (EGFR-TKIs) are effective for EGFR -mutant lung adenocarcinoma (LUAD), resistance inevitably develops through diverse mechanisms, including secondary genetic mutations, amplifications and as-yet undefined processes. To comprehensively unravel the mechanisms of EGFR-TKI resistance, we establish a biobank of patient-derived EGFR -mutant lung cancer organoids, encompassing cases previously treated with EGFR-TKIs. Through comprehensive molecular profiling including single-cell analysis, here we identify a subgroup of EGFR-TKI-resistant LUAD organoids that lacks known resistance-related genetic lesions and instead exhibits a basal-shift phenotype characterized by the hybrid expression of LUAD- and squamous cell carcinoma-related genes. Prospective gene engineering demonstrates that NKX2-1 knockout induces the basal-shift transformation along with EGFR-target therapy resistance. Basal-shift LUADs frequently harbor CDKN2A/B loss and are sensitive to CDK4/6 inhibitors. Our EGFR -mutant lung cancer organoid library not only offers a valuable resource for lung cancer research but also provides insights into molecular underpinnings of EGFR-TKI resistance, facilitating the development of therapeutic strategies. Resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs) is prevalent. Here the authors establish a biobank of patient-derived EGFR-mutant lung cancer organoids and identify a subgroup of EGFR-TKI-resistant lung adenocarcinoma organoids, which exhibit a basal-shift phenotype and vulnerability to CDK4/6 inhibitors.

Vasoactive intestinal peptide (VIP) is a modulator of inflammatory responses. VIP receptors are expressed in several tumor types, such as colorectal carcinoma. The study described herein was conducted to confirm the presence of VIP and its receptors (VPAC1 and VPAC2) in surgically resected hepatocellular carcinoma (HCC) tissues and in the HCC cell line Huh7. The mechanism responsible for apoptosis of HCC cells was then examined because VIP treatment (10−10 M) significantly suppressed proliferation of Huh7 cells. In examining apoptosis‐related proteins, we found caspase‐3 to be significantly increased and Bcl‐xL and cyclic AMP (cAMP) response element‐binding protein (CREB) to be significantly decreased in Huh7 cells cultured with VIP. Furthermore, the CREB level and phosphorylation were reduced. These effects were reversed by the addition of VIP receptor antagonist or cAMP antagonist Rp‐cAMPS. Pretreatment with cAMP analogue blocked the increased apoptosis, suggesting that VIP induces apoptosis via a PKA‐independent signaling mechanism. Our data indicate that VIP prevents the progression of HCC by apoptosis through the cAMP/Bcl‐xL pathway. Immunohistochemical staining for VIP, VPAC1 and VPAC2 in non‐HPV‐B‐related HCC, non‐HPV‐C‐related HCC and Huh7 cells.