bims-instec Biomed News
on Intestinal stem cells and chemoresistance in colon cancer and intestinal regeneration
Issue of 2023‒01‒22
ten papers selected by
Maria-Virginia Giolito
Free University of Brussels

  1. Cell Stem Cell. 2023 Jan 05. pii: S1934-5909(22)00492-1. [Epub ahead of print]
      A central factor in the maintenance of tissue integrity is the response of stem cells to variations in the levels of niche signals. In the gut, intestinal stem cells (ISCs) depend on Wnt ligands for self-renewal and proliferation. Transient increases in Wnt signaling promote regeneration after injury or in inflammatory bowel diseases, whereas constitutive activation of this pathway leads to colorectal cancer. Here, we report that Discs large 1 (Dlg1), although dispensable for polarity and cellular turnover during intestinal homeostasis, is required for ISC survival in the context of increased Wnt signaling. RNA sequencing (RNA-seq) and genetic mouse models demonstrated that DLG1 regulates the cellular response to increased canonical Wnt ligands. This occurs via the transcriptional regulation of Arhgap31, a GTPase-activating protein that deactivates CDC42, an effector of the non-canonical Wnt pathway. These findings reveal a DLG1-ARHGAP31-CDC42 axis that is essential for the ISC response to increased niche Wnt signaling.
    Keywords:  Arhgap31; Cdc42; Dlg1; Wnt; cell death; epithelium; intestine; organoid; regeneration; stem cells
  2. Stem Cell Reports. 2022 Dec 29. pii: S2213-6711(22)00605-1. [Epub ahead of print]
      Adenomatous polyposis coli (APC) mutation is the hallmark of colorectal cancer (CRC), resulting in constitutive WNT activation. Despite decades of research, targeting WNT signaling in cancer remains challenging due to its on-target toxicity. We have previously shown that the deubiquitinating enzyme USP7 is a tumor-specific WNT activator in APC-truncated cells by deubiquitinating and stabilizing β-catenin, but its role in gut tumorigenesis is unknown. Here, we show in vivo that deletion of Usp7 in Apc-truncated mice inhibits crypt hyperproliferation and intestinal tumor development. Loss of Usp7 prolongs the survival of the sporadic intestinal tumor model. Genetic deletion, but not pharmacological inhibition, of Usp7 in Apc+/- intestine induces colitis and enteritis. USP7 inhibitor treatment suppresses growth of patient-derived cancer organoids carrying APC truncations in vitro and in xenografts. Our findings provide direct evidence that USP7 inhibition may offer a safe and efficacious tumor-specific therapy for both sporadic and germline APC-mutated CRC.
    Keywords:  APC; LGR5 stem cell; USP7; Wnt signaling; colorectal cancer
  3. Ann Transl Med. 2022 Dec;10(24): 1335
      Background: Colorectal cancer (CRC) is a malignant tumor associated with a high mortality rate. While the advent of immune checkpoint inhibitors (ICIs) has been a gamechanger, only a small percentage of CRC patients benefit from ICIs. The pathological mechanism of CRC is not well understood, but somatic mutations, especially missense mutations, are believed to play an important role. This study examined the relationship between ICIs in colorectal cancer and missense mutations in the axonemal dynein heavy chain gene 7 (DNAH7).Methods: A clinical cohort (n=690) and the CRC data from the publicly available Cancer Genome Atlas (TCGA) were examined. Gene Set Enrichment Analysis, ESTIMATE analysis, and clinical correlation analysis were performed to explore the effects and mechanisms of DNAH7 mutation on immunotherapy in colorectal cancer.
    Results: The results showed that CRC patients with DNAH7 mutations can benefit more from ICIs (P<0.05). Patients with DNAH7 mutation had higher ESTIMATE scores, immune scores, and matrix scores, compared to patients without the DNAH7 mutation (P<0.001). The transport of small molecules, keratinization, asthma, autoimmune thyroid disease, allograft rejection, and other pathways were significantly enriched in DNAH7 mutated tissues (P<0.05). The top key genes associated with the DNAH7 mutation included AQP8, MS4A12, GUCA2B, and ZG16 (P<0.01).
    Conclusions: The current study not only demonstrated the significance of DNAH7 as a risk factor and prognostic feature in CRC, but also revealed that DNAH7 mutations might affect the clinical efficacy of ICIs by impacting the tumor immune microenvironment.
    Keywords:  Colorectal cancer (CRC); DNAH7; immune checkpoint inhibitors (ICIs); mutation; tumor
  4. Cancer Cell. 2023 Jan 10. pii: S1535-6108(22)00595-5. [Epub ahead of print]
      Interferon-γ (IFN-γ) signaling mediates host responses to infection, inflammation and anti-tumor immunity. Mutations in the IFN-γ signaling pathway cause immunological disorders, hematological malignancies, and resistance to immune checkpoint blockade (ICB) in cancer; however, the function of most clinically observed variants remains unknown. Here, we systematically investigate the genetic determinants of IFN-γ response in colorectal cancer cells using CRISPR-Cas9 screens and base editing mutagenesis. Deep mutagenesis of JAK1 with cytidine and adenine base editors, combined with pathway-wide screens, reveal loss-of-function and gain-of-function mutations, including causal variants in hematological malignancies and mutations detected in patients refractory to ICB. We functionally validate variants of uncertain significance in primary tumor organoids, where engineering missense mutations in JAK1 enhanced or reduced sensitivity to autologous tumor-reactive T cells. We identify more than 300 predicted missense mutations altering IFN-γ pathway activity, generating a valuable resource for interpreting gene variant function.
    Keywords:  IFN-γ signaling; base editing; cancer genetics; cancer immunotherapy; drug resistance; functional genomics; gene editing; interferon gamma; variants of uncertain significance
  5. BMC Cancer. 2023 Jan 16. 23(1): 55
      BACKGROUND: Macrophage infiltration in the tumor microenvironment participates in the regulation of tumor progression. Previous studies have found that Notch signaling pathway is involved in regulating the progression of colorectal cancer (CRC), however, the specific mechanism is still unclear.METHODS: The correlation between Notch signaling pathway and macrophage infiltration was investigated in TCGA database and verified in clinical samples of patients with CRC using immunohistochemistry. Gene Set Enrichment Analysis was used to find out genes related to Notch3 expression. Colony formation assay, and flow cytometry were utilized to test tumor growth and immune cell infiltration in vitro and in vivo.
    RESULTS: Using bioinformatics analysis and clinical sample validation, we found that Notch3 was highly expressed in colon tumor tissues compared to adjacent normal tissues, and it participated in regulating the recruitment of macrophages to the tumor microenvironment. Furthermore, we found that the Notch3 expression was positively correlated with the expression of macrophage recruitment-related cytokines in colon tumor tissues. Finally, we demonstrated that depletion of Notch3 had no significant effect on the growth of colon tumor cells in vitro, while, attenuated the growth of colon cancer tumors in vivo. Simultaneous, immunosuppressive cells, macrophages and myeloid-derived suppressor cell (MDSC) infiltration were dramatically reduced in the tumor microenvironment.
    CONCLUSION: Our study illustrated that Notch3 could facilitate the progression of CRC by increasing the infiltration of macrophages and MDSCs to promote the immunosuppressive tumor microenvironment. Targeting Notch3 specifically is a potentially effective treatment for CRC.
    Keywords:  Colorectal tumor; Macrophage infiltration; Notch3; Tumor microenvironment
  6. Sci Adv. 2023 Jan 20. 9(3): eadd5668
      Spatiotemporally coordinated transformations in epithelial curvature are necessary to generate crypt-villus structures during intestinal development. However, the temporal regulation of mechanotransduction pathways that drive crypt morphogenesis remains understudied. Intestinal organoids have proven useful to study crypt morphogenesis in vitro, yet the reliance on static culture scaffolds limits the ability to assess the temporal effects of changing curvature. Here, a photoinduced hydrogel cross-link exchange reaction is used to spatiotemporally alter epithelial curvature and study how dynamic changes in curvature influence mechanotransduction pathways to instruct crypt morphogenesis. Photopatterned curvature increased membrane tension and depolarization, which was required for subsequent nuclear localization of yes-associated protein 1 (YAP) observed 24 hours following curvature change. Curvature-directed crypt morphogenesis only occurred following a delay in the induction of differentiation that coincided with the delay in spatially restricted YAP localization, indicating that dynamic changes in curvature initiate epithelial curvature-dependent mechanotransduction pathways that temporally regulate crypt morphogenesis.
  7. Cell. 2023 Jan 19. pii: S0092-8674(22)01571-9. [Epub ahead of print]186(2): 363-381.e19
      Advanced solid cancers are complex assemblies of tumor, immune, and stromal cells characterized by high intratumoral variation. We use highly multiplexed tissue imaging, 3D reconstruction, spatial statistics, and machine learning to identify cell types and states underlying morphological features of known diagnostic and prognostic significance in colorectal cancer. Quantitation of these features in high-plex marker space reveals recurrent transitions from one tumor morphology to the next, some of which are coincident with long-range gradients in the expression of oncogenes and epigenetic regulators. At the tumor invasive margin, where tumor, normal, and immune cells compete, T cell suppression involves multiple cell types and 3D imaging shows that seemingly localized 2D features such as tertiary lymphoid structures are commonly interconnected and have graded molecular properties. Thus, while cancer genetics emphasizes the importance of discrete changes in tumor state, whole-specimen imaging reveals large-scale morphological and molecular gradients analogous to those in developing tissues.
    Keywords:  3D microscopy; PD1-PDL1 interaction; cellular; colorectal cancer; intermixed molecular; large-scale; morphological features; multiplexed imaging; spatial gradients; spatial proteomics; spatial transcriptomics; tertiary lymphoid structures; tumor atlas; tumor budding
  8. Cell Rep Med. 2023 Jan 17. pii: S2666-3791(22)00487-6. [Epub ahead of print]4(1): 100908
      In a recent issue of Cancer Cell, Amodio and colleagues report an interesting method of modulating immunosurveillance in colorectal tumors with DNA mismatch repair (MMR) heterogeneity.1 By pharmacologically enriching the MMR deficient (MMRd) component using 6-thioguanine, they demonstrate improved tumor control in murine models.
  9. Drug Metab Pharmacokinet. 2022 Nov 06. pii: S1347-4367(22)00039-8. [Epub ahead of print] 100482
      Rodent-derived intestinal tissues or human colon cancer-derived Caco-2 cells are widely used for in vitro pharmacokinetic tests. However, both entail problems such as species differences from humans and low expression levels of specific pharmacokinetic-related factors, respectively. To solve these problems, many groups, including ours, have been focusing on human biopsy-derived intestinal organoids (b-IOs) and human iPS cell-derived intestinal organoids (i-IOs). However, no reports directly compare the two. Therefore, we established both from a single individual and conducted a comparative study. b-IOs had a shorter doubling time than i-IOs: about 59 h vs 148 h. b-IOs also had higher gene expression levels of major drug transporters and drug-metabolizing enzymes than i-IOs. To evaluate their applicability to pharmacokinetics, both organoids were two-dimensionally cultured. Although the b-IO monolayer had a lower transepithelial electrical resistance than the i-IO monolayer, it had higher gene expression levels of many drug transporters and major drug-metabolizing enzymes than the i-IO monolayer. RNA-seq analysis showed that the i-IOs monolayer had a more complex structure than the b-IOs monolayer because the former contained neuronal and vascular endothelial cells. This study provides basic information for pharmacokinetic applications of human biopsy-derived and human iPS cell-derived intestinal organoids.
    Keywords:  Intestinal first-pass effect; Intestinal organoids; Monolayer culture; Small intestine; iPS cell
  10. Ann Transl Med. 2022 Dec;10(24): 1404
      Background and Objective: In recent years, adoptive cell therapy (ACT) has shown great potential in antitumor treatment. To significantly improve the clinical efficacy of ACT against solid tumors, we may need to carefully study the latest developments in ACT. As one of the most common malignancies, colorectal cancer (CRC) is a major risk to human health and has become a significant burden on global healthcare systems. This article reviews the recent advances in the treatment of CRC with ACT.Methods: We searched PubMed for articles related to ACT for CRC published as of August 31, 2022, and retrieved relevant clinical trial information on the National Institutes of Health website. Based on search results, comprehensive and systematic review is made.
    Key Content and Findings: This article provides an overview of the research progress of ACT for CRC, including chimeric antigen receptor (CAR) T-cell therapy, T-cell receptor (TCR)-engineered T-cell therapy, and tumor-infiltrating lymphocyte (TIL) therapy. Common tumor-associated antigens (TAAs) in clinical trials of CAR-T cell therapy for CRC are described.
    Conclusions: Despite many obstacles, ACT shows great promise in treating CRC. Therefore, more basic experimental studies and clinical trials are warranted to further clarify the effectiveness and safety of ACT.
    Keywords:  Adoptive cellular therapy; clinical trials; colorectal cancer (CRC)