A novel human colon signet-ring cell carcinoma organoid line: establishment, characterization and application.

Colon signet-ring cell carcinoma (SRCC) is a rare type of malignant dedifferentiated adenocarcinomas, and is associated with poor survival. However, an in-depth study of the biological features of SRCC is hindered by the lack of a reliable in vitro model of colon SRCC. Thus, the establishment of cell cultures from SRCC has become the most challenging task. Here, by harnessing the power of the organoid culture system, we describe the establishment of a human colon SRCC organoid line from a surgical sample from one patient with colon SRCC. The colon SRCC organoid line, YQ-173, was characterized for morphology, histology, ultrastructure and chromosome stability levels, showing that it resembles the histological and growth characteristics of the original tumor cells; xenografts were used to show that it also has a high tumor formation rate. RNA sequencing of YQ-173 compared with the normal tissue verified its mucinous nature. Capture-based targeted DNA sequencing combined with drug screening based on a bespoke 88 compound library identified that JAK2 might be a treatment target. An in vitro drug screening found that AT9283 and Pacritinib could be effective JAK2 inhibitors, which was consistent with the in vivo xenograft response. We report, for the first time, the establishment of an SRCC organoid line allowing in-depth study of SRCC biology, as well as a strategy to assess in vitro drug testing in a personalized fashion.

Interleukin-33 Potentiates TGF-ß Signaling to Regulate Intestinal Stem Cell Regeneration After Radiation Injury.

Epithelial regeneration is critical for barrier maintenance and organ function after intestinal radiation injury. Accumulating evidence indicates that the interleukin family members play critical roles in intestinal stem-cell-mediated epithelial regeneration. However, little is known about the relationship between interleukin 33 (IL-33)/ST2 axis and intestinal regeneration after radiation injury. We demonstrate here that IL-33 expression significantly increased after radiation treatment. Deficiency of IL-33/ST2 promotes intestinal epithelial regeneration, resulting in a reduction of mortality during radiation-induced intestine injury. Using ex vivo organoid cultures, we show that recombinant IL-33 promotes intestinal stem cell differentiation. Mechanistically, the effects of IL-33 were mediated by activation of transforming growth factor-ß signaling. Our findings reveal a fundamental mechanism by which IL-33 is able to regulate the intestinal crypt regeneration after tissue damage.

Pharmaco-proteogenomic characterization of liver cancer organoids for precision oncology.

Organoid models have the potential to recapitulate the biological and pharmacotypic features of parental tumors. Nevertheless, integrative pharmaco-proteogenomics analysis for drug response features and biomarker investigation for precision therapy of patients with liver cancer are still lacking. We established a patient-derived liver cancer organoid biobank (LICOB) that comprehensively represents the histological and molecular characteristics of various liver cancer types as determined by multiomics profiling, including genomic, epigenomic, transcriptomic, and proteomic analysis. Proteogenomic profiling of LICOB identified proliferative and metabolic organoid subtypes linked to patient prognosis. High-throughput drug screening revealed distinct response patterns of each subtype that were associated with specific multiomics signatures. Through integrative analyses of LICOB pharmaco-proteogenomics data, we identified the molecular features associated with drug responses and predicted potential drug combinations for personalized patient treatment. The synergistic inhibition effect of mTOR inhibitor temsirolimus and the multitargeted tyrosine kinase inhibitor lenvatinib was validated in organoids and patient-derived xenografts models. We also provide a user-friendly web portal to help serve the biomedical research community. Our study is a rich resource for investigation of liver cancer biology and pharmacological dependencies and may help enable functional precision medicine.

Bach2 Deficiency Promotes Intestinal Epithelial Regeneration by Accelerating DNA Repair in Intestinal Stem Cells.

Epithelial regeneration is critical for barrier maintenance and organ function after intestinal injury, although the repair mechanisms are unclear. Here, we found that Bach2 deficiency promotes intestinal epithelial cell proliferation during homeostasis. Moreover, genetic inactivation of Bach2 in mouse intestinal epithelium facilitated crypt regeneration after irradiation, resulting in a reduction in mortality. RNA-sequencing analysis of isolated crypts revealed that Bach2 deficiency altered the expression of numerous genes, including those regulating double-strand break repair. Mechanistic characterizations indicated that Bach2 deletion facilitated DNA repair in intestinal crypt cells, as evidenced by faster resolution of γ-H2AX and 53BP1 foci in Bach2-/- crypt cells, compared with Bach2+/+ control. Together, our studies highlight that Bach2 deficiency promotes intestinal regeneration by accelerating DNA repair in intestinal stem cells after radiation damage.

CBP/P300 Inhibitors Mitigate Radiation-Induced GI Syndrome by Promoting Intestinal Stem Cell-Mediated Crypt Regeneration.

PURPOSE: Radiation-induced gastrointestinal syndrome (RIGS) is currently the main cause of death for people exposed to a high dose of irradiation during nuclear incidents, and there is currently no approved effective therapy. Here, we found that CBP/P300 inhibitors, with high efficacy and low toxicity, might be promising radiation mitigators that can cure RIGS. METHODS AND MATERIALS: Ex vivo 3D organoid cultures derived from mouse jejunum and human ileum and colon were used to examine the radio-mitigative effects of CBP/P300 inhibitors. The radio-mitigative effect was evaluated by quantifying the survival rate and size of organoids after radiation. SGC-CBP30 (50 mg/kg body weight), an inhibitor of CBP/P300, was intraperitoneally injected into C57B/6J mice 24 hours after subtotal-body irradiation or whole-body irradiation. The regenerated crypts and animal survival were determined by microcolony assay and the Kaplan-Meier method, respectively. Lgr5-lacZ mice were used to evaluate the survival of intestinal stem cells after treatments. RESULTS: We found that CBP/P300 inhibitors were effective mitigators that could be used to treat RIGS. CBP/P300 inhibition promoted the regeneration of intestinal organoids in vitro and of crypts in vivo. Remarkably, the administration of CBP/P300 inhibitors to mice 24 hours after lethal irradiation promoted Lgr5+ intestinal stem cell and crypt recovery, resulting in improved mouse survival. Moreover, our data show that CBP/P300 inhibitors rescued irradiated mice from RIGS by delaying intestinal epithelial cell cycle progression after radiation. CONCLUSIONS: These data demonstrate that CBP/P300 inhibitors are effective medical countermeasures to mitigate gastrointestinal toxicity from radiation.

SIRT1 inhibitors mitigate radiation-induced GI syndrome by enhancing intestinal-stem-cell survival.

High-dose radiation exposure induces gastrointestinal (GI) stem cell death, resulting in denudation of the intestinal mucosa and lethality from GI syndrome, for which there is currently no effective therapy. Studying an intestinal organoid-based functional model, we found that Sirtuin1(SIRT1) inhibition through genetic knockout or pharmacologic inhibition significantly improved mouse and human intestinal organoid survival after irradiation. Remarkably, mice administered with two doseages of SIRT1 inhibitors at 24 and 96 h after lethal irradiation promoted Lgr5+ intestinal stem cell and crypt recovery, with improved mouse survival (88.89% of mice in the treated group vs. 0% of mice in the control group). Moreover, our data revealed that SIRT1 inhibition increased p53 acetylation, resulting in the stabilization of p53 and likely contributing to the survival of intestinal epithelial cells post-radiation. These results demonstrate that SIRT1 inhibitors are effective clinical countermeasures to mitigate GI toxicity from potentially lethal radiation exposure.

Patient-Derived Organoids Predict Chemoradiation Responses of Locally Advanced Rectal Cancer.

Accumulating evidence indicates that patient-derived organoids (PDOs) can predict drug responses in the clinic, but the ability of PDOs to predict responses to chemoradiation in cancer patients remains an open question. Here we generate a living organoid biobank from patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiation (NACR) enrolled in a phase III clinical trial. Our co-clinical trial data confirm that rectal cancer organoids (RCOs) closely recapitulate the pathophysiology and genetic changes of corresponding tumors. Chemoradiation responses in patients are highly matched to RCO responses, with 84.43% accuracy, 78.01% sensitivity, and 91.97% specificity. These data imply that PDOs predict LARC patient responses in the clinic and may represent a companion diagnostic tool in rectal cancer treatment.

Inhibition of SIRT1 promotes taste bud stem cell survival and mitigates radiation-induced oral mucositis in mice.

Taste loss is one of the debilitating complications in radiation-induced oral mucositis (RIOM), as occurs in head and neck cancer patients undergoing radiotherapy. We report here a radio-mitigation effect of Sirtuin 1 (SIRT1) inhibitors in taste bud organoids and a mouse model of radiation-induced taste bud injury. The organoids, developed from circumvallate (CV) papilla, were irradiated with single dose of X-rays and inhibitors of SIRT1 or SIRT2 were added 24 h later. The survival was evaluated by measuring the number and size of regenerated organoids after irradiation (IR). Oral mucositis (OM) was induced by IR of the oral region of Lgr5-lacZ transgenic mice. The surviving Lgr5+ taste bud stem cells were identified after lacZ-staining and the mucosal ulceration on tongue dorsal surface was determined by histological methods. Results showed that SIRT1 inhibitors (nicotinamide, EX527, salermide and sirtinol), but not SIRT2 inhibitors, significantly improve taste bud organoid survival after IR. Remarkably, administration of nicotinamide (NAM), a recognized inhibitor of SIRT1 to mice 24 h after IR promotes the survival of Lgr5+ taste bud stem cells, resulting in alleviated tongue mucositis. In conclusion, SIRT1 inhibitors promote Lgr5+ taste bud stem cell survival and mitigate RIOM in mice. These observations have important implications for efforts to develop therapeutic strategies against taste dysfunction and mucosal ulceration in RIOM.

Activated B Lymphocyte Inhibited the Osteoblastogenesis of Bone Mesenchymal Stem Cells by Notch Signaling.

Estrogen is very important to the differentiation of B lymphocytes; B lymphopoiesis induced by OVX was supposedly involved in osteoporosis. But the effects of B lymphocytes on the osteogenic differentiation of bone mesenchymal stem cells (BMSCs) are not clear. In this study, we detected bone quality and bone loss in a trabecular bone by electronic universal material testing machine and microcomputed tomography (micro-CT) in OVX and splenectomized-ovariectomy (SPX-OVX) rats. Additionally, changes in lymphocytes (B lymphocyte, CD4+ and CD8+ T lymphocytes, and macrophages) in the bone marrow were analyzed by flow cytometry. The osteogenesis of BMSCs cocultured with normal and LPS-pretreated B lymphocytes was detected by BCIP/NBT and Alizarin red S staining. Measurement of the Notch2, Notch4, Hey1, Hey2, Hes1, and runt-related transcription factor 2 (Runx2) expression in BMSCs cocultured with B lymphocytes was done using real-time PCR. The effects of dexamethasone and DAPT (inhibitor of Notch signaling) on osteogenesis of BMSCs were detected by BCIP/NBT, Alizarin red S staining, and real-time PCR. Osteoporosis happened in OVX rats, more serious in SPX-OVX rats, B lymphocytes increased in OVX rats, and sharply higher in SPX-OVX rats. Osteoporosis did not happen in SPX rats which is still companied with a high increase of B lymphocytes. LPS-pretreated B lymphocytes suppressed the osteogenesis of BMSCs, but the normal B lymphocytes could not. The LPS-pretreated B lymphocytes upregulated the expression of Notch4, Hes1, and Hey2 and downregulated the expression of Runx2 in BMSCs. Dexamethasone and DAPT could downregulate the high expression of Notch4, Hes1, Hey2 and upregulate the low expression of Runx2 in BMSCs which cocultured with LPS treated B lymphocytes, the inhibited ALP and Alizarin red staining in BMSCs which cocultured with LPS treated B lymphocytes also partly restored.