bims-instec Biomed News
on Intestinal stem cells and chemoresistance in colon cancer and intestinal regeneration
Issue of 2022‒03‒20
seven papers selected by
Maria-Virginia Giolito

  1. Stem Cell Rev Rep. 2022 Mar 12.
      The intestinal epithelium undergoes rapid cell turnover to maintain the integrity of the mucosal barrier, which is driven by the proliferation and differentiation of intestinal stem cells (ISCs). Due to their properties, ISCs are not only vulnerable targets during intestinal damage, but also act as the resources responsible for repair and regeneration. Moreover, the intestinal tract is the largest immune organ in the body, with the greatest number of immune cells including, but not limited to, macrophages, innate lymphoid cells and T cells. With the advance of intestinal organoid culture systems and single-cell RNA sequencing, the effects of immune cells on ISCs have been initially explored. As a component of the stem cell niche, these activated immune cells and their corresponding cytokines directly modulate apoptosis or survival of ISCs, leading to either destruction or protection of the intestinal epithelium in immune-mediated diseases, such as inflammatory bowel disease and graft-versus-host disease. In this review, we describe the effects of various immune cells on ISCs, as well as the mechanisms underlying these effects. We also highlight the remarkable role of ISCs in intestinal pathogenesis and raise the possibility of developing novel and effective therapeutic strategies for immune-mediated diseases based on ISCs.
    Keywords:  Colorectal cancer; Cytokines; Graft-versus-host disease; Immune cells; Inflammatory bowel disease; Innate lymphoid cells; Intestinal stem cells; T cells
  2. Cell Res. 2022 Mar 16.
      Diet can impact on gut health and disease by modulating intestinal stem cells (ISCs). However, it is largely unknown if and how the ISC niche responds to diet and influences ISC function. Here, we demonstrate that Lepr+ mesenchymal cells (MCs) surrounding intestinal crypts sense diet change and provide a novel niche signal to maintain ISC and progenitor cell proliferation. The abundance of these MCs increases upon administration of a high-fat diet (HFD) but dramatically decreases upon fasting. Depletion of Lepr+ MCs resulted in fewer intestinal stem/progenitor cells, compromised the architecture of crypt-villus axis and impaired intestinal regeneration. Furthermore, we showed that IGF1 secreted by Lepr+ MCs is an important effector that promotes proliferation of ISCs and progenitor cells in the intestinal crypt. We conclude that Lepr+ MCs sense diet alterations and, in turn, modulate intestinal stem/progenitor cell function via a stromal IGF1-epithelial IGF1R axis. These findings reveal that Lepr+ MCs are important mediators linking systemic diet changes to local ISC function and might serve as a novel therapeutic target for gut diseases.
  3. STAR Protoc. 2022 Mar 18. 3(1): 101225
      Quiescent cancer stem cells (qCSCs) are a major source of posttreatment relapse, but methods to identify molecular targets for qCSC elimination are limited. Here, we present a protocol using the fluorescent dye PKH26 to isolate label-retaining qCSCs from colorectal cancer (CRC) patient-derived organoids (PDOs). We describe processing of organoids to single cells, followed by PKH26 labeling and FACS-based cell isolation. We then detail steps for functional assays and RNA sequencing. This protocol can also be applied to normal tissue-derived organoids. For complete details on the use and execution of this protocol, please refer to Regan et al. (2021).
    Keywords:  Cancer; Cell Biology; Cell culture; Cell isolation; Cell-based Assays; Flow Cytometry/Mass Cytometry; Organoids; RNAseq; Stem Cells
  4. Stem Cell Reports. 2022 Feb 28. pii: S2213-6711(22)00098-4. [Epub ahead of print]
      Intestinal progenitor cells integrate signals from their niche, and the gut lumen, to divide and differentiate at a rate that maintains an epithelial barrier to microbial invasion of the host interior. Despite the importance of evolutionarily conserved innate immune defenses to maintain stable host-microbe relationships, we know little about contributions of stem-cell immunity to gut homeostasis. We used Drosophila to determine the consequences of intestinal-stem-cell immune activity for epithelial homeostasis. We showed that loss of stem-cell immunity greatly impacted growth and renewal in the adult gut. In particular, we found that inhibition of stem-cell immunity impeded progenitor-cell growth and differentiation, leading to a gradual loss of stem-cell numbers with age and an impaired differentiation of mature enteroendocrine cells. Our results highlight the importance of immune signaling in stem cells for epithelial function in the adult gut.
    Keywords:  Drosophila; IMD; differentiation; immunity; intestinal stem cell; proliferation
  5. Front Oncol. 2022 ;12 805290
      Objective: Aberrant activation of Wnt/β-catenin signaling contributes to the maintenance of cancer stem cells and chemoresistance in colorectal cancer (CRC). Retinoic acid-induced 2 (RAI2) was proved to be a tumor suppressor in CRC in our previous report. In this study, the role of RAI2 in Wnt/β-catenin signaling was further investigated.Methods: As a transcriptional co-regulator, C-terminal Binding Protein 2 (CtBP2) was reported to be involved in Wnt signaling in multiple and complex ways. The correlation of RAI2 and CtBP2 in CRC was analyzed by TCGA dataset, and the interaction between RAI2 and CtBP2 was explored by co-immunoprecipitation (Co-IP) in CRC cells. The effect of RAI2 on the activity of Wnt signaling and the location of β-catenin was detected by Dual-Luciferase reporter assay and Immunofluorescence respectively. Western blotting analysis was performed to detect the expression of target genes involved in Wnt signaling. Sphere formation assay was employed to detect the effect of RAI2 on stem cell like properties. Cell viability assay was used to detect the chemosensitivity of cells before and after transfection of RAI2.
    Results: The interaction between RAI2 and CtBP2 was confirmed by Co-IP in CRC cells. Besides, the negative correlation of RAI2 and CtBP2 in CRC was found by analyzing the TCGA dataset. Re-expression of RAI2 in human colon cancer cells (HCT116 and LoVo) suppressed the fluorescent activity of Wnt signaling, increased the phosphorylation and inhibited nuclear translocation of β-catenin, with down-regulation of target genes like c-Myc, CyclinD1, ASCL2, and LGR5. In contrast, the mutated RAI2, which can't interact with CtBP2, has no above effects. We observed low expression of RAI2 in 33.89% (101/298) of CRC patients, which was significantly associated with reduced phosphorylation of β-catenin (r=0.8866, P<0.0001), poor 5-year relapse-free survival (RFS) (P = 0.0029) and overall survival (OS) (P = 0.0102). Restoration of RAI2 in HCT116 and LoVo cells inhibited stem cell-like properties of CRC cells and increased chemosensitivity of these cells to oxaliplatin and fluorouracil.
    Conclusion: Low expression of RAI2 can serve as an independent poor prognostic marker. RAI2 inhibits Wnt signaling by interacting with or down-regulating CtBP2, resulting in repression of stem cell-like properties and increased chemosensitivity of CRC cells.
    Keywords:  RAI2; Wnt/β-catenin signaling; chemosensitivity; colorectal cancer; stem cell-like properties
  6. J Chemother. 2022 Mar 14. 1-13
      Therapeutic approaches of advanced colorectal cancer are more complex, here we present a living biobank of patient-derived tumoroids from advanced colorectal cancer patients and show examples of how these tumoroids can be used to to simulate cancer behavior ex vivo and provide more evidence for tumoroids could be utilized as a predictive platform during chemotherapy treatment to identify the chemotherapy response. Morphological, histological and genomic characterization analysis of colorectal cancer tumoroids was conducted. Further, we treated colorectal cancer tumoroids with different drugs to detect cellular activities to evaluate drug sensitivity using CellTiter-Glo 3 D cell viability assay. Then the drug sensitivity of tumoroids was compared with clinical outcomes. Our results implied that tumoroids recapitulated the histological features of the original tumours and genotypic profiling of tumoroids showed a high-level of similarity to the matched primary tumours. Dose-response curves, area under the curve and tumour inhibitory rate of each therapeutic profiling calculations in tumoroids demonstrated a great diversity and we gained 88.24% match ratio between the sensitivity data of tumoroids with their paired patients' clinical outcomes. tumour inhibitory rate of each treatment parameters in tumoroids performed positive correlation with progression-free survival while area under the curve of each treatment parameters performed negative correlation with progression-free survival of the corresponding patients. In summary, We presented a living biobank of tumoroids from advanced colorectal cancer patients and show tumoroids got great potential for predicting clinical responses to chemotherapy treatment of advanced colorectal cancer.
    Keywords:  Tumoroids; advanced colorectal cancer; chemotherapy; living biobank; patient-derived organoids; personalized medicine program
  7. Biochem Biophys Res Commun. 2022 Mar 10. pii: S0006-291X(22)00359-X. [Epub ahead of print]604 96-103
      Different regions and states of the human colon are likely to have a distinct influence on immune cell functions. Here we studied the immunometabolic mechanisms for spatial immune specialization and dysregulated immune response during ulcerative colitis at single-cell resolution. We revealed that the macrophages and CD8+ T cells in the lamina propria of the human colon possessed an effector phenotype and were more activated, while their lipid metabolism was suppressed compared with those in the epithelial. Also, IgA+ plasma cells accumulated in lamina propria of the sigmoid colon were identified to be more metabolically activated versus those in the cecum and transverse colon, and the improved metabolic activity was correlated with the expression of CD27. In addition to the immunometabolic reprogramming caused by spatial localization colon, we found dysregulated cellular metabolism was related to the impaired immune functions of macrophages and dendritic cells in patients with ulcerative colitis. The cluster of OSM+ inflammatory monocytes was also identified to play its role in resistance to anti-TNF treatment, and we explored targeted metabolic reactions that could reprogram them to a normal state. Altogether, this study revealed a landscape of metabolic reprogramming of human colonic immune cells in different locations and disease states, and offered new insights into treating ulcerative colitis by immunometabolic modulation.
    Keywords:  Anti-TNF therapy Resistance; Human colon; Immunometabolic modulation; Inflammation; Single-cell immunometabolism; Spatial immune specialization; Ulcerative colitis