bims-instec Biomed News
on Intestinal stem cells and chemoresistance in colon cancer and intestinal regeneration
Issue of 2023‒04‒02
seventeen papers selected by
Maria-Virginia Giolito
Free University of Brussels


  1. Curr Top Dev Biol. 2023 ;pii: S0070-2153(23)00001-7. [Epub ahead of print]153 281-326
      The intestinal epithelium plays a key role in digestion and protection against external pathogens. This tissue presents a high cellular turnover with the epithelium being completely renewed every 5days, driven by intestinal stem cells (ISCs) residing in the crypt bases. To sustain this dynamic renewal of the intestinal epithelium, the maintenance, proliferation, and differentiation of ISCs must be precisely controlled. One of the central pathways supporting ISC maintenance and dynamics is the Wnt pathway. In this chapter, we examine the role of Wnt signaling in intestinal epithelial homeostasis and tissue regeneration, including mechanisms regulating ISC identity and fine-tuning of Wnt pathway activation. We extensively discuss the contribution of the stem cell niche in maintaining Wnt signaling in the intestinal crypts that support ISC functions. The integration of these findings highlights the complex interplay of multiple niche signals and cellular components sustaining ISC behavior and maintenance, which together supports the immense plasticity of the intestinal epithelium.
    Keywords:  Intestine; Niche; Stem cell; Wnt signaling
    DOI:  https://doi.org/10.1016/bs.ctdb.2023.01.001
  2. bioRxiv. 2023 Mar 24. pii: 2023.03.23.533814. [Epub ahead of print]
      Cell-to-cell signalling between niche and stem cells regulates tissue regeneration. While the identity of many mediating factors is known, it is largely unknown whether stem cells optimize their receptiveness to niche signals according to the niche organization. Here, we show that Lgr5+ small intestinal stem cells (ISCs) regulate the morphology and orientation of their secretory apparatus to match the niche architecture, and to increase transport efficiency of niche signal receptors. Unlike the progenitor cells lacking lateral niche contacts, ISCs orient Golgi apparatus laterally towards Paneth cells of the epithelial niche, and divide Golgi into multiple stacks reflecting the number of Paneth cell contacts. Stem cells with a higher number of lateral Golgi transported Epidermal growth factor receptor (Egfr) with a higher efficiency than cells with one Golgi. The lateral Golgi orientation and enhanced Egfr transport required A-kinase anchor protein 9 (Akap9), and was necessary for normal regenerative capacity in vitro . Moreover, reduced Akap9 in aged ISCs renders ISCs insensitive to niche-dependent modulation of Golgi stack number and transport efficiency. Our results reveal stem cell-specific Golgi complex configuration that facilitates efficient niche signal reception and tissue regeneration, which is compromised in the aged epithelium.
    DOI:  https://doi.org/10.1101/2023.03.23.533814
  3. Cell Rep. 2023 Mar 30. pii: S2211-1247(23)00335-2. [Epub ahead of print]42(4): 112324
      Patient-derived organoids (PDOs) are widely heralded as a drug-screening platform to develop new anti-cancer therapies. Here, we use a drug-repurposing library to screen PDOs of colorectal cancer (CRC) to identify hidden vulnerabilities within therapy-induced phenotypes. Using a microscopy-based screen that accurately scores drug-induced cell killing, we have tested 414 putative anti-cancer drugs for their ability to switch the EGFRi/MEKi-induced cytostatic phenotype toward cytotoxicity. A majority of validated hits (9/37) are microtubule-targeting agents that are commonly used in clinical oncology, such as taxanes and vinca-alkaloids. One of these drugs, vinorelbine, is consistently effective across a panel of >25 different CRC PDOs, independent of RAS mutational status. Unlike vinorelbine alone, its combination with EGFR/MEK inhibition induces apoptosis at all stages of the cell cycle and shows tolerability and effective anti-tumor activity in vivo, setting the basis for a clinical trial to treat patients with metastatic RAS-mutant CRC.
    Keywords:  CP: Cancer; CP: Stem cell research; colorectal cancer; image-based drug screening; microtubule-targeting agents; organoids; targeted therapy
    DOI:  https://doi.org/10.1016/j.celrep.2023.112324
  4. Int J Mol Sci. 2023 Mar 09. pii: 5252. [Epub ahead of print]24(6):
      The presence of cancer stem cells (CSCs) has been associated with the induction of drug resistance and disease recurrence after therapy. 5-Fluorouracil (5FU) is widely used as the first-line treatment of colorectal cancer (CRC). However, its effectiveness may be limited by the induction of drug resistance in tumor cells. The Wnt pathway plays a key role in the development and CRC progression, but it is not clearly established how it is involved in CSCs resistance to treatment. This work aimed to investigate the role played by the canonical Wnt/β-catenin pathway in CSCs resistance to 5FU treatment. Using tumor spheroids as a model of CSCs enrichment of CRC cell lines with different Wnt/β-catenin contexts, we found that 5FU induces in all CRC spheroids tested cell death, DNA damage, and quiescence, but in different proportions for each one: RKO spheroids were very sensitive to 5FU, while SW480 were less susceptible, and the SW620 spheroids, the metastatic derivative of SW480 cells, displayed the highest resistance to death, high clonogenic capacity, and the highest ability for regrowth after 5FU treatment. Activating the canonical Wnt pathway with Wnt3a in RKO spheroids decreased the 5FU-induced cell death. But the Wnt/β-catenin pathway inhibition with Adavivint alone or in combination with 5FU in spheroids with aberrant activation of this pathway produced a severe cytostatic effect compromising their clonogenic capacity and diminishing the stem cell markers expression. Remarkably, this combined treatment also induced the survival of a small cell subpopulation that could exit the arrest, recover SOX2 levels, and re-grow after treatment.
    Keywords:  cancer stem cells; canonical Wnt signaling; chemoresistance; colon cancer; quiescence induction; tumor spheroids
    DOI:  https://doi.org/10.3390/ijms24065252
  5. J Pathol. 2023 Mar 28.
      Chemotherapy-induced diarrhea causes dehydration, debilitation, infection, and even death, but there are currently no Food and Drug Administration (FDA)-approved drugs for treatment of chemotherapy-induced diarrhea. It is generally believed that the timely regulation of intestinal stem cell (ISC) fate may provide a meaningful solution for intestinal injuries. However, the lineage plasticity of ISCs during and after chemotherapy remains poorly understood. Here, we demonstrated that palbociclib, a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor, regulated the fate of active or quiescent ISCs, provided multilineage protection from the toxicity of several different chemotherapeutics, and accelerated gastrointestinal epithelium recovery. Consistent with in vivo results, we determined that palbociclib enhanced intestinal organoid and ex vivo tissue survival after chemotherapy. Lineage tracing studies have shown that palbociclib protects active ISCs marked by Lgr5 and Olfm4 during chemotherapy and unexpectedly activates quiescent ISCs marked by Bmi1 to immediately participate in crypt regeneration after chemotherapy. Furthermore, palbociclib does not decrease the efficacy of cytotoxic chemotherapy in tumor grafts. The experimental evidence suggests that the combination of CDK4/6 inhibitors with chemotherapy could reduce damage to the gastrointestinal epithelium in patients. © 2023 The Pathological Society of Great Britain and Ireland.
    Keywords:  Bmi1; CDK4/6 inhibitor; Lgr5; chemotherapy-induced diarrhea (CID); intestinal stem cells
    DOI:  https://doi.org/10.1002/path.6078
  6. Front Immunol. 2023 ;14 1122258
      Paneth cells are a group of unique intestinal epithelial cells, and they play an important role in host-microbiota interactions. At the origin of Paneth cell life, several pathways such as Wnt, Notch, and BMP signaling, affect the differentiation of Paneth cells. After lineage commitment, Paneth cells migrate downward and reside in the base of crypts, and they possess abundant granules in their apical cytoplasm. These granules contain some important substances such as antimicrobial peptides and growth factors. Antimicrobial peptides can regulate the composition of microbiota and defend against mucosal penetration by commensal and pathogenic bacteria to protect the intestinal epithelia. The growth factors derived from Paneth cells contribute to the maintenance of the normal functions of intestinal stem cells. The presence of Paneth cells ensures the sterile environment and clearance of apoptotic cells from crypts to maintain the intestinal homeostasis. At the end of their lives, Paneth cells experience different types of programmed cell death such as apoptosis and necroptosis. During intestinal injury, Paneth cells can acquire stem cell features to restore the intestinal epithelial integrity. In view of the crucial roles of Paneth cells in the intestinal homeostasis, research on Paneth cells has rapidly developed in recent years, and the existing reviews on Paneth cells have mainly focused on their functions of antimicrobial peptide secretion and intestinal stem cell support. This review aims to summarize the approaches to studying Paneth cells and introduce the whole life experience of Paneth cells from birth to death.
    Keywords:  Paneth cell; antibacterial peptide; cell death; cell differentiation; intestinal stem cell
    DOI:  https://doi.org/10.3389/fimmu.2023.1122258
  7. Mol Pharm. 2023 Mar 28.
      Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. Despite recent therapeutic advancements, resistance to 5-fluorouracil (5-FU) remains a major obstacle to the successful treatment of this disease. We have previously identified the ribosomal protein uL3 as a key player in the cell response to 5-FU, and loss of uL3 is associated with 5-FU chemoresistance. Natural products, like carotenoids, have shown the ability to enhance cancer cell response to drugs and may provide a safer choice to defeat chemoresistance in cancer. Transcriptome analysis of a cohort of 594 colorectal patients revealed a correlation between uL3 expression and both progression-free survival and response to treatment. RNA-Seq data from uL3-silenced CRC cells demonstrated that a low uL3 transcriptional state was associated with an increased expression of specific ATP-binding cassette (ABC) genes. Using two-dimensional (2D) and three-dimensional (3D) models of 5-FU-resistant CRC cells stably silenced for uL3, we investigated the effect of a novel therapeutic strategy by combining β-carotene and 5-FU using nanoparticles (NPs) as a drug delivery system. Our results indicated that the combined treatment might overcome 5-FU chemoresistance, inducing cell cycle arrest in the G2/M phase and apoptosis. Furthermore, the combined treatment significantly reduced the expression levels of analyzed ABC genes. In conclusion, our findings suggest that β-carotene combined with 5-FU may be a more effective therapeutic approach for treating CRC cells with low levels of uL3.
    Keywords:  chemoresistance; colorectal cancer; nanoparticles; ribosomal protein uL3; β-carotene
    DOI:  https://doi.org/10.1021/acs.molpharmaceut.2c00876
  8. Sci Adv. 2023 Mar 29. 9(13): eadf0927
      Cell state plasticity is carefully regulated in adult epithelia to prevent cancer. The aberrant expansion of the normally restricted capability for cell state plasticity in neoplasia is poorly defined. Using genetically engineered and carcinogen-induced mouse models of intestinal neoplasia, we observed that impaired differentiation is a conserved event preceding cancer development. Single-cell RNA sequencing (scRNA-seq) of premalignant lesions from mouse models and a patient with hereditary polyposis revealed that cancer initiates by adopting an aberrant transcriptional state characterized by regenerative activity, marked by Ly6a (Sca-1), and reactivation of fetal intestinal genes, including Tacstd2 (Trop2). Genetic inactivation of Sox9 prevented adenoma formation, obstructed the emergence of regenerative and fetal programs, and restored multilineage differentiation by scRNA-seq. Expanded chromatin accessibility at regeneration and fetal genes upon Apc inactivation was reduced by concomitant Sox9 suppression. These studies indicate that aberrant cell state plasticity mediated by unabated regenerative activity and developmental reprogramming precedes cancer development.
    DOI:  https://doi.org/10.1126/sciadv.adf0927
  9. Curr Stem Cell Res Ther. 2023 Mar 30.
      BACKGROUND: Despite effective clinical responses, a large proportion of patients undergo resistance to radiotherapy. The low response rate to current treatments in different stages of colorectal cancer depends on the prominent role of stem cells in cancer.OBJECTIVE: In the present study, the role of BMP-2 as an ionizing radiation-sensitive factor in colorectal cancer cells was investigated.
    METHODS: A sphere formation assay was used for the enrichment of HCT-116 cancer stem cells (CSCs). The effects of combination therapy (BMP-2+ radiation) on DNA damage response (DDR), proliferation, and apoptosis were evaluated in HCT-116 and CSCs. Gene expressions of CSCs and epithelial-mesenchymal transition (EMT) markers were also evaluated.
    RESULTS: We found that the sphere formation assay showed a significant increase in the percentage of CSCs. Moreover, expression of CSCs markers, EMT-related genes, and DNA repair proteins significantly decreased in HCT-116 cells compared to the CSCs group after radiation. In addition, BMP-2 promoted the radiosensitivity of HCT-116 cells by decreasing the survival rate of the treated cells at 2, 4, and 6 Gy compared to the control group in HCT-116 cells.
    CONCLUSION: Our findings indicated that BMP-2 could affect numerous signaling pathways involved in radioresistance. Therefore, BMP-2 ‎ can be considered an appealing therapeutic target for the treatment of radioresistant human colorectal cancer.
    Keywords:  BMP-2; cancer stem cells; colorectal cancer; epithelial-mesenchymal transition; radioresistancecolorectal cancer; radiosensitivity
    DOI:  https://doi.org/10.2174/1574888X18666230330085615
  10. Cancer Discov. 2023 Mar 31. OF1
      Urea cycle activity in colorectal cancer is associated with the absence of ureolytic gut bacteria.
    DOI:  https://doi.org/10.1158/2159-8290.CD-RW2023-050
  11. Int J Mol Sci. 2023 Mar 16. pii: 5678. [Epub ahead of print]24(6):
      Current 3D cancer models (in vitro) fail to reproduce complex cancer cell extracellular matrices (ECMs) and the interrelationships occurring (in vivo) in the tumor microenvironment (TME). Herein, we propose 3D in vitro colorectal cancer microtissues (3D CRC μTs), which reproduce the TME more faithfully in vitro. Normal human fibroblasts were seeded onto porous biodegradable gelatin microbeads (GPMs) and were continuously induced to synthesize and assemble their own ECMs (3D Stroma μTs) in a spinner flask bioreactor. Then, human colon cancer cells were dynamically seeded onto the 3D Stroma μTs to achieve the 3D CRC μTs. Morphological characterization of the 3D CRC μTs was performed to assess the presence of different complex macromolecular components that feature in vivo in the ECM. The results showed the 3D CRC μTs recapitulated the TME in terms of ECM remodeling, cell growth, and the activation of normal fibroblasts toward an activated phenotype. Then, the microtissues were assessed as a drug screening platform by evaluating the effect of 5-Fluorouracil (5-FU), curcumin-loaded nanoemulsions (CT-NE-Curc), and the combination of the two. When taken together, the results showed that our microtissues are promising in that they can help clarify complex cancer-ECM interactions and evaluate the efficacy of therapies. Moreover, they may be combined with tissue-on-chip technologies aimed at addressing further studies in cancer progression and drug discovery.
    Keywords:  5-Fluorouracil (5-FU); cancer associated fibroblasts (CAF); curcumin-loaded nanoemulsion (CT-NE-Curc); extracellular matrix (ECM); tumor microenvironment (TME)
    DOI:  https://doi.org/10.3390/ijms24065678
  12. Int J Mol Sci. 2023 Mar 15. pii: 5600. [Epub ahead of print]24(6):
      The study of the tumor microenvironment (TME) has become an important part of colorectal cancer (CRC) research. Indeed, it is now accepted that the invasive character of a primary CRC is determined not only by the genotype of the tumor cells, but also by their interactions with the extracellular environment, which thereby orchestrates the development of the tumor. In fact, the TME cells are a double-edged sword as they play both pro- and anti-tumor roles. The interaction of the tumor-infiltrating cells (TIC) with the cancer cells induces the polarization of the TIC, exhibiting an antagonist phenotype. This polarization is controlled by a plethora of interconnected pro- and anti-oncogenic signaling pathways. The complexity of this interaction and the dual function of these different actors contribute to the failure of CRC control. Thus, a better understanding of such mechanisms is of great interest and provides new opportunities for the development of personalized and efficient therapies for CRC. In this review, we summarize the signaling pathways linked to CRC and their implication in the development or inhibition of the tumor initiation and progression. In the second part, we enlist the major components of the TME and discuss the complexity of their cells functions.
    Keywords:  colorectal cancer; dual function; effectors; signaling pathways; tumor microenvironment
    DOI:  https://doi.org/10.3390/ijms24065600
  13. Front Oncol. 2023 ;13 1121787
      Introduction: Cancer Stem Cells (CSC) are responsible for maintaining tumor growth, chemoresistance, and metastasis. Therefore, understanding their characteristics is critical to progress in cancer therapy. While the contribution of the canonical Wnt/b-catenin signaling in both normal and CSCs had been well established, the function of non-canonical Wnt signaling cascades in stem cells is unclear. Recently, we reported that Wnt ligands trigger complex signaling in which the canonical and non-canonical responses can be simultaneously activated by one ligand in colon cancer cells, suggesting, therefore, that noncanonical Wnt pathways may also be important in CSCs.Methods: The present work aimed to know the role of the Wnt/Ca2+ pathway in colon CSCs. We used tumorspheres as a model of CSCs enrichment of CRC cell lines with different Wnt/b-catenin contexts.
    Results: Using Wnt3a and Wnt5a as prototype ligands to activate the canonical or the non-canonical pathways, respectively, we found that both Wnt3a and Wnt5a promote sphere-formation capacity and proliferation without stimulating b-catenin-dependent transcription. Upregulation of sphere formation by Wnt5a or Wnt3a requires the downstream activation of Phospholipase C and transcriptional factor NFAT. Moreover, the single specific inhibition of PLC or NFAT, using U73122 and 11R-VIVIT, respectively, leads to impaired sphere formation.
    Discussion: Our results indicate that both types of ligands activate the Wnt/Ca2+ signaling axis to induce/maintain the self-renewal efficiency of CSCs, demonstrating to be essential for the functions of CSC in colon cancer.
    Keywords:  NFAT; PLC; cancer stem cell; non-canonical Wnt/Ca2+ signaling; tumor spheres
    DOI:  https://doi.org/10.3389/fonc.2023.1121787
  14. J Cancer Res Clin Oncol. 2023 Mar 28.
      BACKGROUND: Prolyl hydroxylase 1 (PHD1) is a prognostic marker in several cancers.AIMS AND SCOPES: This study was undertaken to elucidate the clinical relevance of PHD1 in colorectal cancer (CRC) prognosis.
    MATERIALS AND METHODS: We compared PHD1 expression on a tissue microarray (TMA) containing samples from 1800 CRCs with corresponding clinicopathological tumor variables and patient survival.
    RESULTS: While PHD1 staining was always high in benign colorectal epithelium, high PHD1 staining was detectable in only 71.8% of CRCs. Low PHD1 staining was associated with advanced tumor stage (p = 0.0101) and shortened overall survival in CRC patients (p = 0.0011). In a multivariable analysis including tumor stage, histological type and PHD1 staining revealed tumor stage and histological type (p < 0.0001 each), but also PHD1 staining (p = 0.0202) to be independent prognostic markers for CRC.
    CONCLUSIONS: In our cohort, loss of PHD1 expression independently identified a subset of CRC patients with poor overall survival and might, thus, be a promising prognostic marker. PHD1 targeting may even allow for specific therapeutic approaches for these patients.
    Keywords:  Colorectal cancer; IHC; PHD1; Tissue microarray
    DOI:  https://doi.org/10.1007/s00432-023-04717-y
  15. Int J Mol Sci. 2023 Mar 18. pii: 5797. [Epub ahead of print]24(6):
      Tumor-associated carbonic anhydrases IX (CAIX) and XII (CAXII) have long been in the spotlight as potential new targets for anti-cancer therapy. Recently, CAIX/CAXII specific inhibitor SLC-0111 has passed clinical phase I study and showed differential response among patients with colorectal cancer (CRC). CRC can be classified into four different consensus molecular subgroups (CMS) showing unique expression patterns and molecular traits. We questioned whether there is a CMS-related CAIX/CAXII expression pattern in CRC predicting response. As such, we analyzed transcriptomic data of tumor samples for CA9/CA12 expression using Cancertool. Protein expression pattern was examined in preclinical models comprising cell lines, spheroids and xenograft tumors representing the CMS groups. Impact of CAIX/CAXII knockdown and SLC-0111 treatment was investigated in 2D and 3D cell culture. The transcriptomic data revealed a characteristic CMS-related CA9/CA12 expression pattern with pronounced co-expression of both CAs as a typical feature of CMS3 tumors. Protein expression in spheroid- and xenograft tumor tissue clearly differed, ranging from close to none (CMS1) to strong CAIX/CAXII co-expression in CMS3 models (HT29, LS174T). Accordingly, response to SLC-0111 analyzed in the spheroid model ranged from no (CMS1) to clear (CMS3), with moderate in CMS2 and mixed in CMS4. Furthermore, SLC-0111 positively affected impact of single and combined chemotherapeutic treatment of CMS3 spheroids. In addition, combined CAIX/CAXII knockdown and more effective treatment with SLC-0111 reduced clonogenic survival of CMS3 modelling single cells. In conclusion, the preclinical data support the clinical approach of targeted CAIX/CAXII inhibition by showing linkage of expression with response and suggest that patients with CMS3-classified tumors would most benefit from such treatment.
    Keywords:  CMS; SLC-0111; carbonic anhydrases; chemotherapy; colorectal cancer; consensus molecular subtypes; targeted inhibition of carbonic anhydrases
    DOI:  https://doi.org/10.3390/ijms24065797
  16. Cancers (Basel). 2023 Mar 20. pii: 1865. [Epub ahead of print]15(6):
      New treatment targets are needed for colorectal cancer (CRC). We define expression of High Mobility Group Box 1 (HMGB1) protein throughout colorectal neoplastic progression and examine the biological consequences of aberrant expression. HMGB1 is a ubiquitously expressed nuclear protein that shuttles to the cytoplasm under cellular stress. HMGB1 impacts cellular responses, acting as a cytokine when secreted. A total of 846 human tissue samples were retrieved; 6242 immunohistochemically stained sections were reviewed. Subcellular epithelial HMGB1 expression was assessed in a CRC Tissue Microarray (n = 650), normal colonic epithelium (n = 75), adenomatous polyps (n = 52), and CRC polyps (CaP, n = 69). Stromal lymphocyte phenotype was assessed in the CRC microarray and a subgroup of CaP. Normal colonic epithelium has strong nuclear and absent cytoplasmic HMGB1. With progression to CRC, there is an emergence of strong cytoplasmic HMGB1 (p < 0.001), pronounced at the leading cancer edge within CaP (p < 0.001), and reduction in nuclear HMGB1 (p < 0.001). In CRC, absent nuclear HMGB1 is associated with mismatch repair proteins (p = 0.001). Stronger cytoplasmic HMGB1 is associated with lymph node positivity (p < 0.001) and male sex (p = 0.009). Stronger nuclear (p = 0.011) and cytoplasmic (p = 0.002) HMGB1 is associated with greater CD4+ T-cell density, stronger nuclear HMGB1 is associated with greater FOXP3+ (p < 0.001) and ICOS+ (p = 0.018) lymphocyte density, and stronger nuclear HMGB1 is associated with reduced CD8+ T-cell density (p = 0.022). HMGB1 does not directly impact survival but is associated with an 'immune cold' tumour microenvironment which is associated with poor survival (p < 0.001). HMGB1 may represent a new treatment target for CRC.
    Keywords:  HMGB1; colorectal cancer; cytokine; lymphocytes; mismatch repair; therapy
    DOI:  https://doi.org/10.3390/cancers15061865
  17. Adv Cancer Res. 2023 ;pii: S0065-230X(22)00096-3. [Epub ahead of print]158 293-335
      Traditional chemotherapy against cancer is often severely hampered by acquired resistance to the drug. Epigenetic alterations and other mechanisms like drug efflux, drug metabolism, and engagement of survival pathways are crucial in evading drug pressure. Herein, growing evidence suggests that a subpopulation of tumor cells can often tolerate drug onslaught by entering a "persister" state with minimal proliferation. The molecular features of these persister cells are gradually unraveling. Notably, the "persisters" act as a cache of cells that can eventually re-populate the tumor post-withdrawal drug pressure and contribute to acquiring stable drug-resistant features. This underlines the clinical significance of the tolerant cells. Accumulating evidence highlights the importance of modulation of the epigenome as a critical adaptive strategy for evading drug pressure. Chromatin remodeling, altered DNA methylation, and de-regulation of non-coding RNA expression and function contribute significantly to this persister state. No wonder targeting adaptive epigenetic modifications is increasingly recognized as an appropriate therapeutic strategy to sensitize them and restore drug sensitivity. Furthermore, manipulating the tumor microenvironment and "drug holiday" is also explored to maneuver the epigenome. However, heterogeneity in adaptive strategies and lack of targeted therapies have significantly hindered the translation of epigenetic therapy to the clinics. In this review, we comprehensively analyze the epigenetic alterations adapted by the drug-tolerant cells, the therapeutic strategies employed to date, and their limitations and future prospects.
    Keywords:  Chromatin structure; Drug-tolerant; Epigenetic; Gene expression; Tumor cell; ncRNAs
    DOI:  https://doi.org/10.1016/bs.acr.2022.12.006