Project description:The discrepancy between organoid and immortalized cell line cultures for cancer target discovery remains unclear. Here, our multi-tiered CRISPR screens reveal in vivo-relevant metabolic dependencies and synthetic lethal pairs that can be uncovered with tumor organoids but not cell lines or even 3D spheroids. These screens identify lanosterol synthase and acetyl-CoA carboxylase inhibitors as effective treatments that impede xenografted tumor growth in mice. These lipid metabolic inhibitors exhibit nanomolar IC50 values across diverse human gastric cancer organoids resistant to first-line treatments. Mechanistically, gastric cancer organoids and in vivo tumor exhibit lipid metabolic adaptations not seen in 2D in vitro cultures. Additionally, enteric neurons modulate lipid metabolism in tumor organoids, altering drug sensitivity by up to two orders of magnitude. A neuron-cocultured CRISPR screen further reveals that acetyl-CoA carboxylase expression determines lanosterol synthase inhibitor efficacy. These findings highlight the critical roles of organoid environment and neuronal interaction in cancer lipid reliance.
Project description:Enteric glia are the predominant cell type in the enteric nervous system yet their identities and roles in gastrointestinal function are not well classified. Using our optimized single nucleus RNA-sequencing method, we identified distinct molecular classes of enteric glia and defined their morphological and spatial diversity. Our findings revealed a functionally specialized biosensor subtype of enteric glia that we call “hub cells.” Deletion of the mechanosensory ion channel PIEZO2 from adult enteric glial hub cells, but not other subtypes of enteric glia, led to defects in intestinal motility and gastric emptying in mice. These results provide insight into the multifaceted functions of different enteric glial cell subtypes in gut health and emphasize that therapies targeting enteric glia could advance the treatment of gastrointestinal diseases.
Project description:Enteric glia are the predominant cell type in the enteric nervous system yet their identities and roles in gastrointestinal function are not well classified. Using an optimized single nucleus RNA-sequencing method, we identified distinct molecular classes of enteric glia and defined their morphological and spatial diversity. Our findings revealed a functionally specialized class of enteric glial cells that we call “hub cells.” Hub cells retain dual functionality: they generate neurons and glia and act as force transducers to regulate intestinal physiology. Deletion of the mechanosensory ion channel PIEZO2 from adult enteric glial hub cells, but not other subtypes of enteric glia, led to defects in intestinal motility and gastric emptying in mice. These results provide insight into the multifaceted functions of different enteric glial cell subtypes in gut health and emphasize that therapies targeting enteric glia could advance the treatment of gastrointestinal diseases.
Project description:Enteric glia are the predominant cell type in the enteric nervous system yet their identities and roles in gastrointestinal function are not well classified. Using an optimized single nucleus RNA-sequencing method, we identified distinct molecular classes of enteric glia and defined their morphological and spatial diversity. Our findings revealed a functionally specialized class of enteric glial cells that we call “hub cells.” Hub cells retain dual functionality: they generate neurons and glia and act as force transducers to regulate intestinal physiology. Deletion of the mechanosensory ion channel PIEZO2 from adult enteric glial hub cells, but not other subtypes of enteric glia, led to defects in intestinal motility and gastric emptying in mice. These results provide insight into the multifaceted functions of different enteric glial cell subtypes in gut health and emphasize that therapies targeting enteric glia could advance the treatment of gastrointestinal diseases.
Project description:Background & Aims: Spasmolytic polypeptide/TFF2-expressing metaplasia (SPEM) is known to emerge following parietal cell loss and during Helicobacter pylori infection, however its role in gastric ulcer repair is unknown. Therefore, we sought to investigate if SPEM plays a role in epithelial regeneration. Methods: Acetic acid ulcers were induced in young (2-3 months) C57BL/6 mice to determine the quality of ulcer repair. Gastric tissue was collected and analyzed to determine the expression of SPEM within the regenerating epithelium. As a comparison to native tissue the expression of SPEM was also identified within cultured gastric mouse-derived organoids. Results: Wound healing in the mice coincided with the emergence of SPEM expressing CD44v within the ulcerated region. The emergence of SPEM was also observed in cultured gastric organoids. Conclusions: These data demonstrate the SPEM may play a role in epithelial regeneration. Conclusions: These data demonstrate the SPEM may play a role in epithelial regeneration. 4 samples were used for ulcerated and uninjured tissue. 1 sample was used for intact tissue and organoid-derived RNA. The 'Ulcerated' samples represent C57BL/6 mice with ulcers and the 'Uninjured' samples represent the healthy controls (for "ulcerated" samples). The "Intact stomach tissue" and "Gastric organoids" samples are other types of samples that compared separately. "Gastric organoids" in this comparison are derived from "Intact stomach tissue".
Project description:Genome-wide mRNA expression profiles of 70 primary gastric tumors from the Australian patient cohort. Like many cancers, gastric adenocarcinomas (gastric cancers) show considerable heterogeneity between patients. Thus, there is intense interest in using gene expression profiles to discover subtypes of gastric cancers with particular biological properties or therapeutic vulnerabilities. Identification of such subtypes could generate insights into the mechanisms of cancer progression or lay the foundation for personalized treatments. Here we report a robust gene-xpression-based clustering of a large collection of gastric adenocarcinomas from Singaporean patients [GSE34942 and GSE15459]. We developed and validated a classifier for the three subtypes in Australian patient cohort. Profiling of 70 primary gastric tumors on Affymetrix GeneChip Human Genome U133 Plus 2.0 Array. All tumors were collected with approvals from Peter MacCallum Cancer Center, Australia; the Research Ethics Review Committee; and signed patient informed consent.