bims-instec Biomed News
on Intestinal stem cells and chemoresistance in colon cancer and intestinal regeneration
Issue of 2022‒03‒13
nine papers selected by
Maria-Virginia Giolito

  1. Stem Cell Reports. 2022 Feb 21. pii: S2213-6711(22)00092-3. [Epub ahead of print]
      The intestine is one of the organs that relies on stem cell function for maintaining tissue homeostasis. Recent findings on intestinal aging show that intestinal architecture, such as villus length, crypt size, and cell composition changes in the aged crypts. The correspondent decline in the regenerative capacity of the intestine is mainly due to a decline in intestinal stem cell function upon aging, as the underlying mechanisms of aging intestinal stem cells are beginning to unravel. This review summarizes our current knowledge on stem cell-intrinsic mechanisms of aging of intestinal stem cells and their connection to extrinsic factors, such as niche cells and microbiota and will introduce recent approaches to attenuate or even revert the aging of intestinal stem cells.
    Keywords:  Cdc42 activity; Wnt; aging; intestinal stem cells
  2. JCI Insight. 2022 Mar 08. pii: e153793. [Epub ahead of print]7(5):
      Recent data establish a logarithmic expansion of leucine rich repeat containing G protein coupled receptor 5-positive (Lgr5+) colonic epithelial stem cells (CESCs) in human colorectal cancer (CRC). Complementary studies using the murine 2-stage azoxymethane-dextran sulfate sodium (AOM-DSS) colitis-associated tumor model indicate early acquisition of Wnt pathway mutations drives CESC expansion during adenoma progression. Here, subdivision of the AOM-DSS model into in vivo and in vitro stages revealed DSS induced physical separation of CESCs from stem cell niche cells and basal lamina, a source of Wnt signals, within hours, disabling the stem cell program. While AOM delivery in vivo under non-adenoma-forming conditions yielded phenotypically normal mucosa and organoids derived thereof, niche injury ex vivo by progressive DSS dose escalation facilitated outgrowth of Wnt-independent dysplastic organoids. These organoids contained 10-fold increased Lgr5+ CESCs with gain-of-function Wnt mutations orthologous to human CRC driver mutations. We posit CRC originates by niche injury-induced outgrowth of normally suppressed mutated stem cells, consistent with models of adaptive oncogenesis.
    Keywords:  Adult stem cells; Colorectal cancer; Oncology; Stem cells; Tight junctions
  3. STAR Protoc. 2022 Mar 18. 3(1): 101218
      Organoids can enable the study of solid tumors initiated from a single cancer stem cell (CSC) ex vivo. We describe a serial tumor organoid plating protocol using primary colorectal cancer (CRC) tissues as a rapid and cost-efficient approach to evaluate the impact of therapeutic interventions on CSC functions. We detail the isolation of primary colorectal CSCs, organoid embedding, serial passaging, and CSC-related analytical techniques. For complete details on the use and execution of this protocol, please refer to Masibag et al. (2021) and Bergin et al. (2021).
    Keywords:  Cancer; Cell isolation; Cell-based Assays; Health Sciences; Microscopy; Organoids; Single Cell; Stem Cells; Tissue Engineering
  4. Cell Biol Int. 2022 Mar 07.
      ARID3A is upregulated in colorectal cancer and can promote the proliferation and metastasis of cancer cells. However, patients with higher level of ARID3A have a better prognosis. This study aimed to uncover the mechanism by which ARID3A benefits the prognosis of colon cancer. Our results indicated that ARID3A upregulation enhanced the chemosensitivity of colon cancer cells to 5-Fluorouracil (5-FU), whereas ARID3A downregulation inhibited the chemosensitivity of colon cancer cells to 5-FU. Through database analysis, we found that AKR1C3, a drug resistance related gene, was the target of ARID3A. Moreover, AKR1C3 was downregulated in colon cancer tissues compared to normal tissues. Next, we assessed the interaction between AKR1C3 and ARID3A, and found that ARID3A inhibited the transcription of AKR1C3, leading to the downregulation of AKR1C3 in colon cancer cells. We also verified that AKR1C3 inhibited the chemosensitivity of colon cancer cells to 5-FU. Moreover, patients with higher ratio of ARID3A to AKR1C3 had a better prognosis. This study suggested that ARID3A promoted chemosensitivity of colon cancer cells by inhibiting AKR1C3 in colon cancer. The ratio of ARID3A to AKR1C3 is a good marker to predict the prognosis of colon cancer patients. This article is protected by copyright. All rights reserved.
    Keywords:  AKR1C3; ARID3A; Colon cancer; chemosensitivity
  5. Cancer Lett. 2022 Mar 04. pii: S0304-3835(22)00092-1. [Epub ahead of print]534 215617
      Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. Abundant metabolic fuels have been implicated as potential drivers of CRC. However, it remains unclear whether fructose, an ample sugar in daily diets, is essential for CRC growth. In the present study, we found that glucose levels were always insufficient in human CRC tissues. Compensating for this, fructose was flexibly utilized by tumor cells as an alternative energy source to maintain proliferation and exert chemotherapy resistance in vitro by upregulating GLUT5, a major fructose transporter encoded by SLC2A5. Mechanistically, in glucose-deprived but fructose-rich environments, GLUT5 could interact with ketohexokinase and inhibit its autophagy-dependent degradation, thus trapping fructose into glycolysis and tricarboxylic acid cycle for the malignant growth of CRC cells. In addition, reducing dietary fructose or pharmacological blockade of fructose utilization significantly reduced CRC growth and sensitized CRC cells to chemotherapy in vivo. Taken together, our findings highlight the role of elevated fructose utilization mediated by the GLUT5-KHK axis in governing CRC growth and imply that efforts to refine fructose intake or inhibit fructose-mediated actions may serve as potential therapeutic strategies.
    Keywords:  Chemotherapy resistance; Colorectal cancer; Fructose metabolism; GLUT5; KHK
  6. Front Cell Dev Biol. 2022 ;10 838332
      Background: 5-Fluorouracil (5-FU) is one of the most effective and widely used chemotherapeutic drugs in the treatment of colon cancer, yet chemoresistance is a common feature of colon cancer treatment, resulting in poor prognosis and short survival. Dynamic reprogramming of chromatin accessibility is crucial for proper regulation of gene transcription associated with cancer drug resistance by providing the gene regulatory machinery with rapid access to the open genomic DNA. Methods: Here, we explored the global chromatin accessibility and transcription changes by the assay for transposase-accessible chromatin using sequencing (ATAC-seq) in combination with transcriptome sequencing of both parental and 5-FU-resistant HCT15 cells, followed by integrative analysis to better understand the regulatory network underlying 5-FU resistance in colon cancer cells. Results: A total of 3,175 differentially expressed mRNAs (DEGs), lncRNAs (DELs), and miRNAs (DEMs) related to 5-FU resistance were identified, including significantly upregulated IL33, H19, and miR-17-5p; the downregulated AKR1B10, LINC01012, and miR-125b-5p; and chromatin modifiers such as INO80C, HDAC6, and KDM5A. The construction of the ceRNA regulatory network revealed that H19, HOXA11-AS, and NEAT1 might function as ceRNAs associated with 5-FU resistance in HCT15 cells. Moreover, 9,868 differentially accessible regions (DARs) were obtained, which were positively (r = 0.58) correlated with their nearest DEGs and DELs. The upregulated genes related to 4,937 hyper-accessible regions were significantly enriched in signaling pathways of MAPK, FOX, and WNT, while the 4,931 hypo-accessible regions were considered to be involved in declined biosynthesis of amino acids and nucleotide sugars, signaling pathways of Notch, and HIF-1. Analyses of the DAR sequences revealed that besides the AP-1 family, the TF motifs of FOX and KLF family members were highly enriched in hyper- and hypo-accessible regions, respectively. Finally, we obtained several critical TFs and their potential targets associated with DARs and 5-FU resistance, including FOXA1 and KLF3. Conclusion: These data provided clear insights and valuable resources for an improved understanding of the non-genetic landscape of 5-FU-resistant colon cancer cells based on chromatin accessibility and transcript levels, which allowed for genome-wide detection of TF binding sites, potential cis-regulatory elements and therapeutic targets.
    Keywords:  5-FU resistance; chromatin accessibility; colon cancer; differentially accessible regions; transcription factors
  7. Cancers (Basel). 2022 Feb 25. pii: 1195. [Epub ahead of print]14(5):
      Proprotein convertases or PCs are known to regulate the malignant phenotype of colon cancer cells by different mechanisms, but their effects on cancer stem cells (CSCs) have been less widely investigated. Here, we report that PCs expression is altered in colon CSCs, and the inhibition of their activity reduced colon CSCs growth, survival, and invasion in three-dimensional spheroid cultures. In vivo, repression of PCs activity by the general PC inhibitors α1-PDX, Spn4A, or decanoyl-RVKR-chloromethylketone (CMK) significantly reduced tumor expression levels of the stem cell markers LGR5 and NANOG that are associated with reduced tumor xenografts. Further analysis revealed that reduced tumor growth mediated by specific silencing of the convertase Furin in KRAS or BRAF mutated-induced colon tumors was associated with reduced expression of LGR5 and NANOG compared to wild-type KRAS and BRAF tumors. Analysis of various calcium regulator molecules revealed that while the calcium-transporting ATPase 4 (ATP2B4) is downregulated in all the Furin-silenced colon cancer cells, the Ca2+-mobilizing P2Y receptors, was specifically repressed in BRAF mutated cells and ORAI1 and CACNA1H in KRAS mutated cells. Taken together, our findings indicate that PCs play an important role in the malignant phenotype of colon CSCs and stem cell markers' expression and highlight PCs repression, particularly of Furin, to target colon tumors with KRAS or BRAF mutation.
    Keywords:  BRAF; KRAS; LGR5; NANOG; calcium; cancer stem cells; colon cancer
  8. Nat Chem Biol. 2022 Mar 10.
      Precision oncology presumes an accurate prediction of drug response on the basis of the molecular profile of tumors. However, the extent to which patient-derived tumor organoids recapitulate the response of in vivo tumors to a given drug remains obscure. To gain insights into the pharmacobiology of human colorectal cancer (CRC), we here created a robust drug screening platform for patient-derived colorectal organoids. Application of suspension culture increased organoid scalability, and a refinement of the culture condition enabled incorporation of normal and precursor organoids to high-throughput drug screening. Drug screening identified bromodomain and extra-terminal (BET) bromodomain protein inhibitor as a cancer-selective growth suppressor that targets genes aberrantly activated in CRC. A multi-omics analysis identified an association between checkpoint with forkhead and ring finger domaines (CHFR) silencing and paclitaxel sensitivity, which was further validated by gene engineering of organoids and in xenografts. Our findings highlight the utility of multiparametric validation in enhancing the biological and clinical fidelity of a drug screening system.
  9. Int J Mol Sci. 2022 Feb 24. pii: 2519. [Epub ahead of print]23(5):
      BACKGROUND: Next to breast cancer, advanced stage metastatic colon cancer represents a major cause for mortality in women. Germline or somatic mutations in tumor suppressor genes or in DNA mismatch repair genes represent risk factors for genetic predisposition of colon cancer that are also detectable in sporadic colon cancer. Conventional chemotherapy for colon cancer includes combination of 5-fluoro-uracil with oxaliplatin and irinotecan or targeted therapy with non-steroid anti-inflammatory drugs and selective cyclooxygenase-2 inhibitors. Major limitations of these therapeutic interventions are associated with systemic toxicity, acquired tumor resistance and the emergence of drug resistant stem cells that favor initiation, progression and metastasis of therapy-resistant disease. These limitations emphasize an unmet need to identify tumor stem cell selective testable alternatives. Drug-resistant stem cell models facilitate the identification of new testable alternatives from natural phytochemicals and herbal formulations. The goal of this review is to provide an overview relevant to the current status of conventional/targeted therapy, the role of cancer stem cells and the status of testable alternatives for therapy-resistant colon cancer. Experimental models: Hyper-proliferative and tumorigenic cell lines from genetically predisposed colonic tissues of female mice represent experimental models. Chemotherapeutic agents select drug-resistant phenotypes that exhibit upregulated expressions of cellular and molecular stem cell markers. Mechanistically distinct natural phytochemicals effectively inhibit stem cell growth and downregulate the expressions of stem cell markers.CONCLUSIONS: The present review discusses the status of colon cancer therapy and inherent limitations, cancer stem cell biology, potential lead compounds and their advantages over chemotherapy. The present experimental approaches will facilitate the identification of pharmacological and naturally-occurring agents as lead compounds for stem cell targeted therapy of colon cancer.
    Keywords:  colon cancer; drug-resistant stem cells; natural products