Cancer stem cells (CSCs) hold a significant role in cancer metastasis, high mortality and severity responsible for therapy resistance and tumour recurrence. The 26S proteasome system plays a major role in protein degradation in normal cells. As most cancers have upregulated 26S proteasome machinery, cancer cells use the 26S proteasome system in their favour for growth support by degrading unwanted proteins, but dysfunction of the 26S proteasome system induces apoptosis in cells. Here, we used hematopoietic stem cells (HSCs) and HSCs-derived conditioned media (CM) to target colorectal cancer stem cells (CRC-CSCs). HSCs are otherwise used extensively to save the lives of patients suffering from hematological malignancies and inherited blood disorders. HSCs-derived conditioned media contains various cytokines, chemokines, and secretory small molecules, which can also target the CRC-CSCs. Moreover, HSCs have exhibited CRC-CSC tropism in vitro in our pilot studies. As therapeutic uses of HSCs for targeting colorectal cancer (CRC) have never been reported, we hypothesized the CRC-CSC targeting properties of HSCs. Our results indicated altered protein function of CRC-CSCs upon co-culture with HSCs. Proteomics approaches showed that HSCs-CM disrupted 26S proteasomal complex and altered the mitochondrial bioenergetics, thereby activating apoptosis in CRC-CSCs. Furthermore, we observed that HSCs-CM significantly induced double-stranded DNA damage and proteasomal degradation, leading to apoptosis and upregulating the autophagy system. This study, hence, provides the prospective targeting of cancer stem cells using HSCs-CM, indicating a possible therapeutic approach.

ARID3A is highly expressed in CRC patients. However, the functional role of ARID3A in CRC remains unexplored. We sought to demonstrate ARID3A function in CRC.

ARID3A was knocked-down using lentiviruses harboring shRNA. CRC patients' tissue cDNA array was used to assess expression of ARID3A. Effect of ARID3A on CSC-associated genes was analysed using real-time PCR array. Western-blot analysis and ChIP assay were used to validate the role of ARID3A. Paclitaxel-resistant CSC-enriched cell population was used to assess correlation between ARID3A, stemness and drug resistance potential. Ex vivo findings were corroborated on preclinical mouse model.

ARID3A expression was significantly higher throughout CRC stages than normal individuals. ARID3A expression was significantly higher in the aggressive CRC cell line HCT116 compared to HT29, which expressed higher levels of CD44, CD133, and EpCAM, suggesting a reciprocal relationship between ARID3A expression and CRC stemness. Real-time PCR-based stem cell array using ARID3A-knockdown HCT116 cells showed upregulation of 9 cancer stem cell (CSC)-associated genes. ChIP-assay verified binding of ARID3A on transcriptionally active promoter regions of CSC associated genes. ARID3A depletion led to enhanced proliferation, anchorage-independent growth, and ABCG2 upregulation in HCT116 cells. In paclitaxel-resistant HCT116 cells, ARID3A expression was dampened, whereas, CD44 and CD133 increased. ARID3A knockdown accelerated tumor growth and promoted larger tumor formation in nude-mouse xenograft model. Ki67, CD44 and CD133 were highly upregulated in knockdown tumors.

This study demonstrated that ARID3A inhibits CRC stemness, anchorage-independent growth, self-renewal, anti-cancer drug resistance of CRC cells and tumor growth in vivo.

Multiple myeloma (MM) is a blood cancer characterized by the uncontrolled growth of plasma cells in the bone marrow. These malignant plasma cells can proliferate locally and spread to other tissues and organs. The M-protein they produce can lead to various clinical symptoms, including anemia, hypercalcemia, bone pain, bone destruction, and kidney dysfunction. Despite significant advancements in treatment over the past two decades that have improved survival and outcomes for many patients, drug resistance remains a significant therapeutic challenge. This resistance is largely driven by the complex interactions between MM cells and the bone marrow microenvironment (BMME), making long-term disease control difficult. To improve treatment outcomes, it is essential to understand how the BMME supports MM cell growth and survival, as well as how these cells evade therapies. Investigating these processes will help identify key mechanisms behind drug resistance, offering a pathway to develop targeted therapies that can overcome this challenge. This review will explore the intricate relationship between MM cells and the BMME, focusing on how both cellular and non-cellular components of the microenvironment contribute to resistance mechanisms and prompt disease progression. These insights aim to inform future therapeutic strategies to enhance treatment options for MM patients.

The presence of cancer stem cells (CSCs) is one of the primary causes of recurring therapy resistance because they have two main capacities: self-renewal and avoiding apoptotic pathways. Despite their relevance, no full bibliometric analysis has yet been done in this topic. The goal of this work is to use bibliometric analysis to map the fundamental and emergent areas in therapeutics targeting colon cancer stem cells. To perform bibliometric analysis on colon cancer stem cells (CCSCs) literature, spanning roughly the last 40 years, in order to establish a firm base for future projections by emphasizing the findings of the most notable research. All information pertinent to CCSCs was accessed from Web of Science Core Collection database. In order to identify and analyze the research hotspots and trends related to this topic, Biblioshiny (RStudio) and VOSviewer were utilized to ascertain the countries/regions, institutions, journals, authors, references, and keywords involved. The targeted time span covered 1735 research-, and review articles. The most frequent keywords were "colorectal cancer," "cancer stem cells," and "colon cancer," while the most trending keywords in the last few years were "protein stability," "spheroid formation," "ubiquitination," "exosomes," "patient-derived organoids," and "gut microbiota." Over the past 40 years, there has been a significant advancement in researchers' understanding of colon cancer stem cells. In addition, the cluster map of co-cited literature showed that colon cancer stem cell research has emerged as a research hotspot. It was also anticipated that the main focus of the future efforts appears to involve clinical applications of cell-targeted colon cancer therapy. These results provide researchers with a comprehensive understanding of this field and provide insightful ideas for further research.

Mounting evidence underscores the prevalent hierarchical organization of cancer tissues. At the foundation of this hierarchy reside cancer stem cells, a subset of cells endowed with the pivotal role of engendering the entire cancer tissue through cell differentiation. In recent times, substantial attention has been directed toward the phenomenon of cancer cell plasticity, where the dynamic interconversion between cancer stem cells and nonstem cancer cells has garnered significant interest. Since the task of detecting cancer cell plasticity from empirical data remains a formidable challenge, we propose a Bayesian statistical framework designed to infer phenotypic plasticity within cancer cells, utilizing temporal data on cancer stem cell proportions. Our approach is grounded in a stochastic model, adept at capturing the dynamic behaviors of cells. Leveraging Bayesian analysis, we scrutinize the moment equation governing cancer stem cell proportions, derived from the Kolmogorov forward equation of our stochastic model. Our methodology introduces an improved Euler method for parameter estimation within nonlinear ordinary differential equation models, also extending insights to compositional data. Extensive simulations robustly validate the efficacy of our proposed method. To further corroborate our findings, we apply our approach to analyze published data from SW620 colon cancer cell lines. Our results harmonize with in situ experiments, thereby reinforcing the utility of our method in discerning and quantifying phenotypic plasticity within cancer cells.

Cancer stem cells (CSCs) constitute a small yet crucial subgroup in tumors, known for their capacity to self-renew, differentiate, and promote tumor growth, metastasis, and resistance to therapy. These characteristics position CSCs as significant factors in tumor recurrence and unfavorable clinical results, emphasizing their role as targets for therapy. Autophagy, an evolutionarily preserved cellular mechanism for degradation and recycling, has a complex function in cancer by aiding cell survival during stress and preserving balance by eliminating damaged organelles and proteins. Although autophagy can hinder tumor growth by reducing genomic instability, it also aids tumor advancement, particularly in harsh microenvironments, highlighting its dual characteristics. Recent research has highlighted the complex interactions between autophagy and CSCs, showing that autophagy governs CSC maintenance, boosts survival, and aids in resistance to chemotherapy and radiotherapy. On the other hand, in specific situations, autophagy may restrict CSC growth by increasing differentiation or inducing cell death. These intricate interactions offer both obstacles and possibilities for therapeutic intervention. Pharmacological modulation of autophagy, via inhibitors like chloroquine or by enhancing autophagy when advantageous, has demonstrated potential in making CSCs more responsive to standard treatments. Nonetheless, applying these strategies in clinical settings necessitates a better understanding of context-dependent autophagy dynamics and the discovery of dependable biomarkers indicating autophagic activity in CSCs. Progressing in this area might unveil novel, accurate strategies to tackle therapy resistance, lessen tumor recurrence, and ultimately enhance patient outcomes.

The immunosuppressive nature of the tumor microenvironment (TME) and the existence of cancer stem cells (CSCs) present significant hurdles in tumor therapy. The identification of therapeutic agents that can target both CSCs and the TME could be a potential approach to overcome treatment resistance.

We conducted an in vivo chemical screen to identify F1929-1458, which is capable of eliciting an organism-wide response to destroy stem cell tumors in Drosophila. We then performed functional validation using a mouse colorectal cancer graft tumor model established with the CT26 cell line characterized by its high content of CSCs. Single-cell sequencing was employed to analyze alterations in the TME. Small molecule pull-down mass spectrometry, cellular thermal shift assay, drug affinity experiment, and molecular docking were utilized to identify the target of F1929-1458. An in vitro co-culture system was applied to establish that the damage-associated molecular patterns (DAMPs) released by the tumor cells are accountable for the activation of dendritic cells (DCs).

We demonstrated that F1929-1458 treatment enhanced T cell infiltration and T cell mediated tumor regression, its anti-tumor effect was nullified in nude mice and was abolished after anti-CD3 neutralizing antibody treatment. We found that F1929-1458 binds NFKB1 to activate the NF-κB signaling pathway in tumor cells. The activation further elicits cellular stress, causing tumor cells to release DAMPs (HMGB1-gDNA complex, ATP, and OxLDL). These DAMPs, in turn, stimulate the cGAS-STING and NLRP3 inflammasome pathways in DCs, resulting in the generation of type I IFNs and IL-1β. These cytokines facilitate the maturation of DCs and antigen presentation, ultimately enhancing T cell-mediated anti-tumor immunity. Additionally, we showed that the combination of F1929-1458 and the anti-PD-1 antibody exhibited a synergistic anti-tumor effect.

Our study identified a novel NFKB1 agonist that promotes anti-tumor immunity by remodeling the TME and activating DCs and that may provide a new way to overcome resistance to current anti-tumor immunotherapy in colorectal cancer.

One of the key challenges in defeating advanced tumors is the ability of cancer cells to evade the selective pressure imposed by chemotherapy, targeted therapies, immunotherapy and cellular therapies. Both genetic and epigenetic alterations contribute to the development of resistance, allowing cancer cells to survive initially effective treatments. In this narration, we explore how genetic and epigenetic regulatory mechanisms influence the state of tumor cells and their responsiveness to different therapeutic strategies. We further propose that an altered balance between cell growth and cell death is a fundamental driver of drug resistance. Cell death programs exist in various forms, shaped by cell type, triggering factors, and microenvironmental conditions. These processes are governed by temporal and spatial constraints and appear to be more heterogeneous than previously understood. To capture the intricate interplay between death-inducing signals and survival mechanisms, we introduce the concept of Death-ision. This framework highlights the dynamic nature of cell death regulation, determining whether specific cancer cell clones evade or succumb to therapy. Building on this understanding offers promising strategies to counteract resistant clones and enhance therapeutic efficacy. For instance, combining DNMT inhibitors with immune checkpoint blockade may counteract YAP1-driven resistance or the use of transcriptional CDK inhibitors could prevent or overcome chemotherapy resistance. Death-ision aims to provide a deeper understanding of the diversity and evolution of cell death programs, not only at diagnosis but also throughout disease progression and treatment adaptation.

Glioblastoma is a fatal and aggressive cancer with no cure. It is becoming increasingly clear that glioblastoma initiation is a result of adult neural stem cell (NSC) transformation-most likely those within the subventricular zone (SVZ). Indeed, transcriptomic analysis indicates that glioblastomas are reminiscent of a neurodevelopmental hierarchy, in which neural stem and progenitor markers are widely expressed by tumour stem-like cells. However, NSC fates and the cues that drive them are poorly understood. Studying the crosstalk within NSC niches may better inform our understanding of glioblastoma initiation and development. Insulin-like growth factor binding protein 2 (IGFBP-2) has a well-established prognostic role in glioblastoma, and cell-based mechanistic studies show the independent activation of downstream oncogenic pathways. However, IGFBP-2 is more commonly recognised as a modulator of insulin-like growth factors (IGFs) for receptor tyrosine kinase signal propagation or attenuation. In the adult human brain, both IGFBP-2 and IGF-II expression are retained in the choroid plexus (ChP) and secreted into the cerebral spinal fluid (CSF). Moreover, secretion by closely associated cells and NSCs themselves position IGFBP-2 and IGF-II as interesting factors within the NSC niche. In this review, we will highlight the experimental findings that show IGFBP-2 and IGF-II influence NSC behaviour. Moreover, we will link this to glioblastoma biology and demonstrate the requirement for further analysis of these factors in glioma stem cells (GSCs).

Despite advances in cancer immunotherapies across various cancers, survival outcomes in colorectal cancer (CRC) with these agents remain largely unsatisfactory despite the high tumour burden. Colorectal stem cells (CSCs), especially LGR5+ CSCs, are the significant drivers in CRC initiation, progression and resistance to conventional therapies. Although native immune surveillance is sufficient to combat early tumour formation, CRC evades early immune detection with its well-documented adenoma-to-carcinoma sequence. The exact mechanism underlying this phenomenon still needs to be better understood. SRY-related HMG box gene 17 (SOX17), a transcription factor that specifies embryonic gut formation, is increasingly recognised as a significant factor in CRC tumourigenesis. However, its role as a tumour suppressor or oncogene is still debated. Evidence from a recent study highlighted the critical role of SOX17 in reshaping the tumour immune ecosystem through the simultaneous inhibition of CD8+ T cells and selective suppression of LGR5 expression in CSCs through transcriptional repression, thereby facilitating disease progression. Given its role in immune evasion, SOX17 could be a promising marker in personalised therapy. Additionally, SOX17 could play a role in the diagnostic arena, potentially identifying dysplasia in the gastrointestinal tract. Future clinical, basic and genetic studies focusing on SOX17 are needed to ascertain its mechanistic role in tumour immunomodulation in CRC and diagnosing preneoplastic lesions in the gastrointestinal tract.

Colorectal cancer (CRC) recurs at a striking rate, specifically in patients with liver metastasis. Dormant CRC cells disseminated following initial primary tumor resection or treatment often resurface years later to form aggressive, therapy-resistant tumors that result in high patient mortality. Routine imaging-based screenings often fail to detect dormant cancer cell clusters, and there are no overt symptomatic presentations, making dormant CRC a major clinical challenge to diagnose and treat. Tissue engineering approaches are ideally suited to model dormant cancer cells and enable the discovery of therapeutic vulnerabilities or unique mechanistic dependencies of dormant CRC. Emerging evidence suggests that tissue-engineered approaches have been successfully used to model dormant breast and lung cancer. With CRC responsible for the second most cancer-related deaths worldwide and CRC patients commonly experiencing recurrence, it is essential to expand dormancy models to understand this phenomenon in the context of CRC. Most published in vitro models of CRC dormancy simplify the complex tumor microenvironment with two-dimensional culture systems to elucidate dormancy-driving mechanisms. Building on this foundation, future research should apply tissue engineering methods to this growing field to generate competent three-dimensional models and increase mechanistic knowledge. This review summarizes the current state of in vitro CRC dormancy models, highlighting the techniques utilized to give rise to dormant CRC cells: nutrient depletion, anticancer drugs, physical extracellular matrix interactions, and genetic manipulation. The metrics used to validate dormancy within each model are also consolidated to demonstrate the lack of established standards and the ambiguity around comparing studies that have been validated differently. The methods of these studies are organized in this review to increase comprehensibility and identify needs and opportunities for future bioengineered in vitro models to address dormancy-driven mortality in patients with CRC liver metastasis. Impact Statement Dormant cancer drives high patient mortality, especially in metastatic colorectal cancer, owing to the clinical inability to identify dormant cells prior to their overt recurrence. Lacking clinical insights, in vitro modeling for mechanistic and therapeutic discovery is hindered. Here, we review models and methods of inducing colorectal cancer dormancy with the goal of consolidating findings for reference. We also highlight the need for advanced, tissue-engineered models to better mimic the organ-specific 3D microenvironment of metastatic colorectal cancer. New models would enable breakthroughs in understanding mechanisms driving dormancy progression and reversal, thereby providing context for therapeutic advances to improve patient survival.

Meningiomas (MGs), which arise from meningothelial cells of the dura mater, represent a significant proportion of primary tumours of the central nervous system (CNS). Despite advances in treatment, the management of malignant meningioma (MMG) remains challenging due to diagnostic, surgical, and resection limitations. Cancer stem cells (CSCs), a subpopulation within tumours capable of self-renewal and differentiation, are highlighted as key markers of tumour growth, metastasis, and treatment resistance. Identifying additional CSC-related markers enhances the precision of malignancy evaluations, enabling advancements in personalised medicine. The review discusses key CSC biomarkers that are associated with high levels of expression, aggressive tumour behaviour, and poor outcomes. Recent molecular research has identified CSC-related biomarkers, including Oct-4, Sox2, NANOG, and CD133, which help maintain cellular renewal, proliferation, and drug resistance in MGs. This study highlights new therapeutic strategies that could improve patient prognosis with more durable tumour regression. The use of combination therapies, such as hydroxyurea alongside diltiazem, suggests more efficient and effective MG management compared to monotherapy. Signalling pathways such as NOTCH and hedgehog also offer additional avenues for therapeutic development. CRISPR/Cas9 technology has also been employed to create meningioma models, uncovering pathways related to cell growth and proliferation. Since the efficacy of traditional therapies is limited in most cases due to resistance mechanisms in CSCs, further studies on the biology of CSCs are warranted to develop therapeutic interventions that are likely to be effective in MG. Consequently, improved diagnostic approaches may lead to personalised treatment plans tailored to the specific needs of each patient.

AXL, a receptor tyrosine kinase, has recently emerged as a potential therapeutic target against various types of cancer. Gilteritinib, a FDA-approved small-molecule inhibitor, is used for the treatment of patients with FLT3-mutated acute myeloid leukemia. However, the antitumor activity of gilteritinib in solid tumors remains poorly elucidated. In this study, we explored the antitumor activity of gilteritinib in AXL-expressing esophageal cancer (EC), ovarian cancer (OC), and gastric cancer (GC), along with the underlying molecular mechanisms. Our data demonstrated that gilteritinib significantly inhibited cell proliferation and spheroid formation by triggering apoptosis and cell cycle arrest in AXL-positive EC, OC, and GC cells. Moreover, we found that gilteritinib treatment repressed EC, OC, and GC cell migration and invasion. Mechanistically, RNA-seq analysis revealed that gilteritinib significantly downregulated multiple cancer-related pathways, including those related to apoptosis, the cell cycle, the mTOR pathway, the AMPK pathway, the p53 pathway, the FOXO pathway, the Hippo pathway, and the Wnt pathway. Gilteritinib inhibited a unique set of E2F- and MYC target-associated genes in EC, OC, and GC cells. Intriguingly, interrogation of the EC, OC, and GC cohort demonstrated that these genes were overexpressed and associated with poor prognosis. Gilteritinib also displayed strong antitumor effects on AXL-positive PDX-derived explants (PDXEs) and PDX-derived organoids (PDXOs) ex vivo and PDXs in vivo. Collectively, these findings reveal that gilteritinib represents a potent therapeutic agent for the treatment of AXL-positive solid tumors. Zhang et al. demonstrate superior therapeutic efficacy of Gilteritinib, a FDA-approved small-molecule inhibitor, in the AXL-expressing esophageal cancer, ovarian cancer and gastric cancer cell lines, PDXOs and PDXs models. This work highlights Gilteritinib as a novel and potent therapeutic approach for the treatment of AXL-positive solid tumors.

The cap-binding complex (CBC) plays a crucial role in facilitating gene expression by safeguarding mRNA from nonsense-mediated decay, promoting mRNA splicing, 3'-end processing, and facilitating nuclear export. Nevertheless, the precise biological functions and clinical implications of CBC in cancer remain ambiguous, necessitating further investigation for clarification.

The present study utilized the cBioPortal database to investigate the genetic alterations of nuclear cap binding protein subunit 2 (NCBP2) in pan-cancer. The Cancer Genome Atlas (TCGA) and online web tools were employed to analyze the correlation between NCBP2 and prognosis, genome instability, immune infiltration, immune response, cancer stemness, and chemotherapeutic efficacy in pan-cancer. Furthermore, the expression of NCBP2 was confirmed by immunohistochemistry (IHC) and functional analysis at the single-cell level was conducted using the CancerSEA database.

NCBP2 exhibited distinct genetic alterations in pan-cancer with an increased expression in 24/32, while decreased expression in 3/32, types of cancers. IHC confirmed the aberrant expression of NCBP2 in lung squamous cell carcinoma (LUSC), pancreatic adenocarcinoma (PAAD), kidney renal papillary cell carcinoma (KIRP) and kidney renal clear cell carcinoma (KIRC). NCBP2 was correlated with overall survival (OS), disease-specific survival (DSS), and progression-free survival (PFS) in various cancers. Importantly, it was identified as a risk factor for OS, DSS and PFS in PAAD and uterine corpus endometrial carcinoma (UCEC). Gene Set Enrichment Analysis (GSEA) demonstrated that elevated NCBP2 was linked to immune and proliferation related pathways across multiple cancer types. Furthermore, a negative association between NCBP2 and stromal score, immune score, and ESTIMATE score was detected, and a positive correlation was observed between NCBP2 and diverse immune cells as well as stemness-indexes in the majority of cancer types. Drug sensitivity analysis revealed that drugs associated with NCBP2 primarily targeted DNA replication, chromatin histone methylation, ABL signaling, cell cycle, and PI3K signaling. Additionally, an examination at the single-cell level indicated that NCBP2 was positively correlated with cell cycle progression, DNA damage, DNA repair, invasion, and stemness in most cancer types, while negatively correlated with apoptosis, inflammation, and hypoxia in certain cancers.

In this study, we revealed the correlation of NCBP2 with prognosis, microenvironment and stemness, indicating that NCBP2 might be a potential therapeutic target for more effective and personalized therapy strategies in pan-cancer.

Colorectal cancer (CRC) remains a leading cause of cancer-related morbidity and mortality worldwide, driven by a complex interplay of genetic, environmental, and immune-related factors. Among the pivotal pathways implicated in CRC tumorigenesis, the Notch signaling pathway is instrumental in governing cell fate decisions, tissue renewal, homeostasis, and immune cell development. As a highly conserved mechanism, Notch signaling not only modulates tumor cell behavior but also shapes the immune landscape within the tumor microenvironment (TME). Aberrant Notch signaling in CRC fosters immune evasion and tumor progression through its effects on the balance and functionality of immune cells, including myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). Elevated Notch pathway activation correlates with advanced clinicopathological features and poorer clinical outcomes, highlighting its relevance as both a prognostic biomarker and a therapeutic target. Therapeutic approaches aimed at inhibiting the Notch pathway, such as γ-secretase inhibitors (GSIs) or monoclonal antibodies (mAbs) in combination with other therapies, have demonstrated promising efficacy in preclinical and clinical settings. This review examines the impact of Notch signaling on CRC immunity, elucidating its regulatory mechanisms within immune cells and its role in promoting tumor progression. Additionally, this review discusses therapeutic strategies targeting Notch signaling, including GSIs, mAbs, and potential combination therapies designed to overcome resistance and improve patient outcomes. By elucidating the multifaceted role of Notch within the CRC TME, this review underscores its potential as a target for innovative therapeutic strategies.

Head and Neck Squamous Cell Carcinomas (HNSCC) are the seventh most prevalent form of cancer and are associated with human papilloma virus infection (HPV-positive) or with tobacco and alcohol use (HPV-negative). HPV-negative HNSCCs have a high recurrence rate, and individual patients' responses to treatment vary greatly due to the high level of cellular heterogeneity of the tumor and its microenvironment. Here, we describe a HNSCC single cell atlas, which we created by integrating six publicly available datasets encompassing over 230,000 cells across 54 patients. We contextualized the relationships between existing signatures and cell populations, identified new subpopulations, and show the power of this large-scale resource to robustly identify associations between transcriptional signatures and clinical phenotypes that would not be possible to discover using fewer patients. We reveal a previously undefined myeloid population, sex-associated changes in cell type proportions, and novel interactions between CXCL8-positive fibroblasts and vascular endothelial cells. Beyond our findings, the atlas will serve as a public resource for the high-resolution characterization of tumor heterogeneity of HPV-negative HNSCC.

The targeting of cancer stem cells (CSCs) has proven to be an effective approach for limiting tumor progression, thus necessitating the identification of new drugs with anti-CSC activity. Through a high-throughput drug repositioning screen, we identify the antibiotic Nifuroxazide (NIF) as a potent anti-CSC compound. Utilizing a click chemistry strategy, we demonstrate that NIF is a prodrug that is specifically bioactivated in breast CSCs. Mechanistically, NIF-induced CSC death is a result of a synergistic action that combines the generation of DNA interstrand crosslinks with the inhibition of the Fanconi anemia (FA) pathway activity. NIF treatment mimics FA-deficiency through the inhibition of STAT3, which we identify as a non-canonical transcription factor of FA-related genes. NIF induces a chemical HRDness (Homologous Recombination Deficiency) in CSCs that (re)sensitizes breast cancers with innate or acquired resistance to PARP inhibitor (PARPi) in patient-derived xenograft models. Our results suggest that NIF may be useful in combination with PARPi for the treatment of breast tumors, regardless of their HRD status.

Cell plasticity emerges as a novel cancer hallmark and is pivotal in driving tumor heterogeneity and adaptive resistance to different therapies. Cancer stem-like cells (CSCs) are considered the root of cancer. While first defined as tumor-initiating cells with the potential to develop a heterogeneous tumor, CSCs further demonstrate their roles in cancer metastasis and adaptive therapeutic resistance. Generally, CSCs come from the malignant transformation of somatic stem cells or the de-differentiation of other cancer cells. The resultant cells gain more plasticity and are ready to differentiate into different cell states, enabling them to adapt to therapies and metastatic ecosystems. Therefore, CSCs are likely the nature of tumor cells that gain cell plasticity. However, the phenotypic plasticity of CSCs has never been systematically discussed. Here, we review the distinct intrinsic signaling pathways and unique microenvironmental niches that endow CSC plasticity in solid tumors to adapt to stressful conditions, as well as emerging opportunities for CSC-targeted therapy.

Cancer is a heterogeneous disease, which contributes to its rapid progression and therapeutic failure. Besides interpatient tumor heterogeneity, tumors within a single patient can present with a heterogeneous mix of genetically and phenotypically distinct subclones. These unique subclones can significantly impact the traits of cancer. With the plasticity that intratumoral heterogeneity provides, cancers can easily adapt to changes in their microenvironment and therapeutic exposure. Indeed, tumor cells dynamically shift between a more differentiated, rapidly proliferating state with limited tumorigenic potential and a cancer stem cell (CSC)-like state that resembles undifferentiated cellular precursors and is associated with high tumorigenicity. In this context, CSCs are functionally located at the apex of the tumor hierarchy, contributing to the initiation, maintenance, and progression of tumors, as they also represent the subpopulation of tumor cells most resistant to conventional anti-cancer therapies. Although the CSC model is well established, it is constantly evolving and being reshaped by advancing knowledge on the roles of CSCs in different cancer types. Here, we review the current evidence of how CSCs play a pivotal role in providing the many traits of aggressive tumors while simultaneously evading immunosurveillance and anti-cancer therapy in several cancer types. We discuss the key traits and characteristics of CSCs to provide updated insights into CSC biology and highlight its implications for therapeutic development and improved treatment of aggressive cancers.

We describe a novel device to mimic the metastasis of cancer cells from the colon into the liver in a human model. The colon mimic is connected to the liver model by a gravity-driven recirculating unidirectional flow of a blood surrogate and can mimic the five steps of the metastatic cascade: invasion in the colon, intravasation into the bloodstream, systemic transportation, extravasation into the liver, and colonization in the liver. The colon mimic uses established normal colon epithelial organoid cells (NL) and human umbilical vein endothelial cells (HUVEC) plated on opposite sides of a membrane. To better mimic the colon structure the NL side of the membrane is exposed to air to establish an air-liquid interface. The liver mimic consists of human liver sinusoidal endothelial cells (HHSEC) and epithelial hepatic cells (HepG2 C3A) plated in Matrigel on opposite sides of a membrane. Labeled colorectal cancer cells/clusters (CA) from organoids are introduced into an established normal colon epithelial cell (NL) layer from the same patient before assembly of the system or alternatively NL organoids and fluorescently labeled CA organoids from the same patient were prepared as a ratio of 10:1 NL:CA and established together before assembly of the system. Cell viability is greater than 85% in this system. We demonstrate that over 5 days of operation that the five steps of the metastatic cascade are replicated. This novel device allows an in vitro estimate of metastatic capability (as measured by using percentages of the labeled areas per device through ImageJ) in response to selected variables. In this study, the metastatic capability depends on the source of cancer cells (e.g., the patient), the clumping of cancer cells, glucose concentration, and oxygen levels (hypoxia). For the first time, this new in vitro system mimics all five steps of the metastatic cascade in a single device and provides a new device to probe and observe the process of metastasis in a human-based model in only 5 days. The rapid observation is due to the use of a high concentration of cancer cells in the colon (e.g. 10%) and the absence of the immune system. Our device makes it possible to probe aspects of each step of metastasis and interactions between steps.

Prominin-1, or CD133, is a membrane-bound pentaspan protein that has been utilized recently to identify cancer stem cells (CSCs) in a variety of carcinomas. Today, bioinformatics offers a potent tool for studying the structural and functional relationships of fusion proteins. A structure-activity relationship model based on physicochemical characteristics, biological functions of single-chain antibodies, and molecular conformation can be developed by the integration of biomolecular computer models with biological experiments. In the present study, a mice library of single-chain variable fragment (scFv) antibodies was developed by mRNA extracted from mice immunized for the efficient and specific identification of the N-terminal domain of recombinant CD133 (D-EC1). First, a part of sequences of the scFvs library were cloned in the T.vector and sequenced. Then, bioinformatics was used to select the scFvs with high affinity by molecular dynamics simulations and docking. Based on bioinformatics analysis, three scFvs were cloned and expressed. Finally, the ability of the selected scFv was confirmed with the indirect enzyme-linked immunosorbent assay (ELISA) and immunocytochemistry (ICC). ELISA data showed that scFv3 had a greater affinity for the N-terminal of recombinant CD133, and it was selected for the immunocytochemistry (ICC) analysis. The immunocytochemistry experiments confirmed that the obtained scFv could bind to the CD133-expressing HT-29 cells. Our results suggest that using bioinformatics tools could be applied as a new, rapid, and valid method for the design and development of antibodies with improved properties. The selected scFv may be successfully applied in scFv-based diagnostics and therapeutics.

Patient-derived xenograft (PDX) models are powerful tools in cancer research, offering an accurate platform for evaluating cancer treatment efficacy and predicting responsiveness. However, these models necessitate surgical techniques for tumor tissue transplantation and face challenges with non-uniform tumor growth among animals. To address these issues, we attempted to develop a new PDX modeling method using high-grade serous ovarian cancer (HGSC), a fatal disease with a 5-year survival rate of 29%, which requires personalized research due to its morphological, genetic, and molecular heterogeneities. In this study, we developed a new patient-derived cancer cell xenograft (PDCX) model with high engraftment efficiency (64%) that utilizes primary cancer cells instead of patient tissues. Primary cancer cells can be stably cryopreserved for extended periods (up to 485 days), and when transplanted into female NSGA mice, they maintain morphological and molecular characteristics without significant genetic differences compared to their original primary tumors. Furthermore, PDCX models can be easily produced using a syringe, allowing for uniform tumor sizes across multiple animals. Additionally, M2 PDCXs exhibited a significantly faster growth rate compared to M2 PDTXs. Consequently, our PDCX model offers a streamlined approach for evaluating personalized cancer treatments with minimal experimental variability.

Malignant melanoma is a lethal skin cancer containing melanoma-initiating cells (MICs), implicated in tumorigenesis, invasion, and drug resistance, and characterized by an elevated expression of stem cell markers, including CD133. siRNA knockdown of CD133 has been previously shown to enhance apoptosis induced by the MEK inhibitor trametinib in melanoma cells. This study investigates the underlying mechanisms of CD133's anti-apoptotic activity in patient-derived BAKP melanoma, harboring the difficult-to-treat NRASQ61K driver mutation, after CRISPR-Cas9 CD133 knockout or Doxycycline (Dox)-inducible re-expression of CD133. CD133 knockout in BAKP cells increased trametinib-induced apoptosis by reducing anti-apoptotic p-AKT and p-BAD and increasing pro-apoptotic BAX. Conversely, Dox-induced CD133 expression diminished apoptosis in trametinib-treated cells, coincident with elevated p-AKT, p-BAD, and decreased activation of BAX and caspase-3. However, trametinib in combination with pan-AKT inhibitor capivasertib reduced cell survival as measured by XTT viability assays and apoptosis and colony formation assays, independent of CD133 status. CD133 may therefore activate a survival pathway wherein (1) increased AKT phosphorylation and activation induces (2) BAD phosphorylation and inactivation, which (3) decreases BAX activation, and (4) reduces caspases-3 activity and caspase-mediated PARP cleavage, leading to apoptosis suppression and drug resistance in melanoma. In vivo mouse xenograft studies using Dox-inducible melanoma cells revealed increased rates of tumor growth after induction of CD133 expression in trametinib-treated +Dox mice, an effect which was synergistically suppressed by combination treatment. Targeting nodes of the AKT and MAPK survival pathways with trametinib and capivasertib highlights the potential for combination therapies for NRAS-mutant melanoma stem cells for the development of more effective treatments for patients with high-risk melanoma.

Clear-cell renal cell carcinoma (ccRCC) is the most common subtype of kidney malignancy. ccRCC is considered a major health concern worldwide because its numbers of incidences and deaths continue to rise and are predicted to continue rising in the foreseeable future. Therefore new strategy for early diagnosis and therapeutics for this disease is urgently needed. The discovery of cancer stem cells (CSCs) offers hope for early cancer detection and treatment. However, there has been no definitive identification of these cancer progenitors for ccRCC. A majority of ccRCC is characterized by the loss of the von Hippel-Lindau (VHL) tumor suppressor gene function. Recent advances in genome analyses of ccRCC indicate that in ccRCC, tumor-initiating cells (TICs) and metastasis-initiating cells (MICs) are two distinct groups of progenitors. MICs result from various genetic changes during subclonal evolution, while TICs reside in the stem of the ccRCC phylogenetic tree of clonal development. TICs likely originate from kidney tubule progenitor cells bearing VHL gene inactivation, including chromatin 3p loss. Recent studies also point to the importance of microenvironment reconstituted by the VHL-deficient kidney tubule cells in promoting ccRCC initiation and progression. These understandings should help define the progenitors of ccRCC and facilitate early detection and treatment of this disease.

Pancreatic cancer is an extremely deadly illness for which there are few reliable treatments. Recent research indicates that malignant tumors are highly variable and consist of a tiny subset of unique cancer cells, known as cancer stem cells (CSCs), which are responsible for the beginning and spread of tumors. These cells are typically identified by the expression of specific cell surface markers. A population of pancreatic cancer stem cells with aberrantly active developmental signaling pathways has been identified in recent studies of human pancreatic tumors. Among these Notch signaling pathway has been identified as a key regulator of CSCs self-renewal, making it an attractive target for therapeutic intervention. Chrysin-loaded polylactic acid (PLA) as polymeric nanoparticles systems have been growing interest in using as platforms for improved drug delivery. This review aims to explore innovative strategies for targeted therapy and optimized drug delivery in pancreatic CSCs by manipulating the Notch pathway and leveraging PLA-based drug delivery systems. Furthermore, we will assess the capability of PLA nanoparticles to enhance the bioavailability and effectiveness of gemcitabine in pancreatic cancer cells. The insights gained from this review have the potential to contribute to the development of novel treatment approaches that combine targeted therapy with advanced drug delivery utilizing biodegradable polymeric nanoparticles.

The intestinal stem cell (ISC) niche is vital for maintaining the integrity and function of the intestinal epithelium. ISC populations, characterized by their high proliferation and multipotency, reside within a specialized microenvironment at the base of crypts. Crypt base columnar (CBC) cells at the deepest part of crypts serve as replicating ISCs, while position 4 label-retaining cells (LRCs) located higher up in the crypts are also important for ISC maintenance during experiments. The interplay between CBCs, position 4 LRCs, transient amplifying (TA) cells and other niche components, including the pericrypt stromal cells, ensures a continuous supply of differentiated epithelial cells. Recent advancements in ISC biomarker studies have provided valuable insights into their molecular signatures, regulatory pathways and roles in the pathogenesis of intestinal disorders. Understanding the ISC niche has significant therapeutic implications, as manipulating ISC behaviors and regenerating damaged or diseased intestinal tissue show promise for novel therapeutic approaches. ISC organoids have also provided a platform for studying intestinal diseases and testing personalized therapies. This comprehensive review covers the anatomical composition, physiological regulation, ISC biomarker studies, contribution to intestinal disorder pathogenesis and potential therapeutic implications of the ISC niche.

Accumulating evidence supports the idea that cancer stem cells (CSCs) are those with the capacity to initiate tumors, generate phenotypical diversity, sustain growth, confer drug resistance, and orchestrate the spread of tumor cells. It is still controversial whether CSCs originate from normal stem cells residing in the tissue or cancer cells from the tumor bulk that have dedifferentiated to acquire stem-like characteristics. Although CSCs have been pointed out as key drivers in cancer, knowledge regarding their physiology is still blurry; thus, research focusing on CSCs is essential to designing novel and more effective therapeutics. The purinergic system has emerged as an important autocrine-paracrine messenger system with a prominent role at multiple levels of the tumor microenvironment, where it regulates cellular aspects of the tumors themselves and the stromal and immune systems. Recent findings have shown that purinergic signaling also participates in regulating the CSC phenotype. Here, we discuss updated information regarding CSCs in the purinergic system and present evidence supporting the idea that elements of the purinergic system expressed by this subpopulation of the tumor represent attractive pharmacological targets for proposing innovative anti-cancer therapies.

The presence of cancer stem cells is linked to aggressive disease and higher risk of recurrence, and multiple markers have been proposed to detect cancer stem cells. However, a detailed evaluation of the expression patterns and the prognostic value of markers relevant for endometrial cancer is lacking. As organoid models are suggested to be enriched in cancer stem cells, such models may prove valuable to define tissue-specific cancer stem cells. To address this, imaging mass cytometry and multiplex single-cell analyses were performed on an endometrial cancer patient series including both tumor biopsies and corresponding patient-derived organoids. An antibody panel focused on cancer stem cell markers was used to identify cancer stem cell phenotypes. Over 70% of epithelial cells in the tumor biopsies expressed at least one putative cancer stem cell marker. We identified distinct cancer cell phenotypes with heterogeneous expression within individual patients and between patient samples. Few differences in the distribution of cancer cell phenotypes were observed between tumor biopsies and corresponding organoids. Cells expressing aldehyde dehydrogenase 1 (ALDH1) were more prevalent in high-grade tumors, while expression of CD44 was more prevalent in grade 1 tumors. Spatial analysis revealed significantly less interaction between ALDH1- and CD44-expressing cells. Gene expression data was used to further investigate selected markers. CD44 gene expression was associated with a favorable prognosis and was further validated using immunohistochemistry. High expression of CD44 was significantly associated with better survival. The general high expression of proposed stem cell markers may indicate alternative roles for these in endometrial cancer.

Extracellular membrane vesicles (EVs) offer promising values in various medical fields, e.g., as biomarkers in liquid biopsies or as native (or bioengineered) biological nanocarriers in tissue engineering, regenerative medicine and cancer therapy. Based on their cellular origin EVs can vary considerably in composition and diameter. Cell biological studies on mammalian prominin-1, a cholesterol-binding membrane glycoprotein, have helped to reveal new donor membranes as sources of EVs. For instance, small EVs can originate from microvilli and primary cilia, while large EVs might be produced by transient structures such as retracting cellular extremities of cancer cells during the mitotic rounding process, and the midbody at the end of cytokinesis. Here, we will highlight the various subcellular origins of prominin-1+ EVs, also called prominosomes, and the potential mechanism(s) regulating their formation. We will further discuss the molecular and cellular characteristics of prominin-1, notably those that have a direct effect on the release of prominin-1+ EVs, a process that might be directly implicated in donor cell reprogramming of stem and cancer stem cells. Prominin-1+ EVs also mediate intercellular communication during embryonic development and adult homeostasis in healthy individuals, while disseminating biological information during diseases.

The high mortality rate of metastatic colorectal cancer (CRC) is primarily attributed to resistance to chemotherapy, where cancer stem cells (CSCs) play a crucial role. Deubiquitinating enzymes are essential regulators of CSC maintenance, making them potential targets for eliminating CSCs and overcoming chemotherapy resistance. This study aims to identify key deubiquitinating enzymes regulating CSCs and drug resistance of CRC.

RNA sequencing was performed to examine the mRNA expression of known deubiquitinating enzymes in CRC tissues from patients with alternate response to chemotherapy. Gain- and loss-of-function experiments were performed to evaluate the function of USP4 in regulation of stemness and drug sensitivity in CRC. High-throughput virtual screening and target management assays were conducted to identify small molecule inhibitor targeting USP4. Cell lines, organoids and animal models were used to evaluate the function of USP4 and its small molecule inhibitor in stemness and chemotherapy response.

The expression of USP4 was significantly elevated in CRC samples from progressive disease (PD) or stable disease (SD) patients compared to partial response (PR) specimen. USP4 promoted stemness by stabilizing the β-catenin and Twist1 proteins in CRC cells. A natural small molecule product U4-I05 diminished the stem-like features of CSCs and enhanced their sensitivity to oxaliplatin and 5-fluorouracil by targeting inhibition of its deubiquitinating enzyme activity through binding the catalytic domain of USP4 (311 cysteine site) at nanomolar concentrations, triggering proteasome-mediated degradation of β-catenin and Twist1. Treatment with U4-I05 also inhibited tumor metastasis and extended survival in a genetically engineered CRC mouse model.

This study identifies U4-I05 as a USP4 inhibitor with significant therapeutic efficacy against CRC, offering a promising avenue for the development of new treatments targeting cancer stemness and chemotherapy resistance.

Oncological diseases consistently occupy leading positions among the most life-threatening diseases, including in highly developed countries. At the same time, the second most common cause of cancer death is colorectal cancer. The current level of research shows that the development of effective therapy, in this case, requires a new grade of understanding processes during the emergence and development of a tumor. In particular, the concept of cancer stem cells that ensure the survival of chemoresistant cells capable of giving rise to new tumors is becoming widespread. To provide adequate conditions that reproduce natural processes typical for tumor development, approaches based on increasingly complex cellular systems are being improved. This review discusses the main strategies that allow for the study of the properties of tumor cells with an emphasis on colorectal cancer stem cells. The features of working with tumor cells and the advantages and disadvantages of 2D and 3D culture systems are considered.

The existence of cancer stem cells (CSCs) in various tumors has become increasingly clear in addition to their prominent role in therapy resistance, metastasis, and recurrence. For early diagnosis, disease progression monitoring, and targeting, there is a high demand for clinical-grade methods for quantitative measurement of CSCs from patient samples. Despite years of active research, standard measurement of CSCs has not yet reached clinical settings, especially in the case of solid tumors. This is because detecting this plastic heterogeneous population of cells is not straightforward. This review summarizes various techniques, highlighting their benefits and limitations in detecting CSCs from patient samples. In addition, methods designed to detect CSCs based on secreted and niche-associated signaling factors are reviewed. Spatial and single-cell methods for analyzing patient tumor tissues and noninvasive techniques such as liquid biopsy and in vivo imaging are discussed. Additionally, methods recently established in laboratories, preclinical studies, and clinical assays are covered. Finally, we discuss the characteristics of an ideal method as we look toward the future.

Cancer stem cells (CSCs) cause therapy-resistance and recurrence, therefore an establishment of therapeutic approaches targeting CSCs is essential for eradicating cancers; however, a lot of aspects of the mechanisms of CSCs generation remain unclear. We previously demonstrated that human glioblastoma cell lines cultured on double-network (DN) hydrogel were rapidly reprogrammed into CSCs. To elucidate molecular mechanisms underlying CSCs generation, we here focused on the elastic modulus of hydrogels mimicking the stiffness of tumor tissues. Mouse NIH3T3 fibroblasts transformed with representative oncogenes H-Ras and Src were employed as cancer model cells, and cultured on (2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) gel with different elastic modulus. The H-Ras-, but not Src-, transformed NIH3T3 cells induced stem cell properties on the PAMPS gel, particularly with elastic modulus of approximately 10 kPa that mimics general tumor tissues. On the gels, expression levels of stemness markers such as Sox2, Nanog, and Oct4 were increased in the parental and H-Ras-transformed cells. Pull-down assay demonstrated that multiple proteins in H-Ras-transformed cells bound to the PAMPS gels with 9.3 kPa stiffness, and desmoplakin was identified as one of the gel-bound proteins by LC-MS/MS analysis. Among Ca2+ channels functioning as mechanosensors, the expression levels of TRPC and TRPV families were efficiently increased on the gel with approximately 10 kPa, as well as stemness markers. These data suggest that tumor tissues with the stiffness of 10 kPa effectively trigger the signals for generating CSCs through alterations of membrane structures and Ca2+ influx, which will be beneficial for developing novel therapeutic applications targeting CSCs.

Colon cancer is one of the most common cancer-related deaths. Drug resistance is one of the biggest challenges in cancer treatment. Numerous pharmacological and biochemical investigations have documented the benzimidazole ring's anticancer, anti-inflammatory, and antioxidant properties. Within the scope of our project, the effect of newly synthesized benzimidazolium salt (BS) on cell proliferation was tested with MTT assay, and its effect on apoptosis and cell cycle was tested with annexin V and PI in the two different colon cancer cell lines (HT-29 and DLD-1). Our study examined the expressions of some genes related to apoptosis and, additionally, caspase activities with the multicaspase kit. BS showed an antiproliferative effect at lower doses in HT-29 colon cancer cells. When HT-29 cells were exposed to a 20 µM dosage, they showed increased caspase activity and apoptosis compared to DLD-1 cells. HT-29 accumulated in the G2/M phase of the cell cycle, whereas DLD-1 cells accumulated more in the S phase. In HT-29 cells, colony formation was inhibited; however, in DLD-1 cells, this effect was insufficient. Based on the apoptosis-death pathway, BS is expected to have anti-cancer effects. As a result of this work, this chemical was thoroughly examined in two different colon cancer cell lines, and additional, more comprehensive initiatives are being planned in light of the information obtained from this study.

Cancer stem cells (CSCs) are implicated as the underlying cause of tumor recurrence due to their refractoriness to conventional therapies. Targeting CSCs through novel approaches can hinder their survival and proliferation, potentially reducing the challenges associated with tumor relapse. Our previous study demonstrated that colorectal cancer stem cells (CR-CSCs) showed sensitivity to Vitamin C (Vit C), displaying a dose-responsive effect where low doses (2-10 µM) promoted cell proliferation while high doses induced cell death. In this study, we unraveled the mechanistic effects of low doses that, although induced proliferation, remarkably facilitated stemness reduction in HT-29 cell line-derived CR-CSCs. Our findings revealed that Vit C doses of 2 and 6 µM resulted in a reduction in stemness as evidenced by a reduced CD44+ cell population, representing CR-CSCs. The key finding was the remarkable increase in the expression of β-catenin protein following low-dose Vit C treatment, despite a reduction in stemness, accompanied by a mesenchymal to epithelial transition (MET). The sequestration of upregulated β-catenin via E-cadherin to the cell membrane was identified as a mechanism for reduced stemness, MET, and differentiation of CR-CSCs. Importantly, the epithelial phenotype induced by low-dose Vit C rendered CR-CSCs sensitive to conventional treatments, enhancing chemosensitivity to Cisplatin, Paclitaxel, and 5-Fluorouracil by 60%-90%. These findings suggest that low dose Vit C could serve as an adjuvant to conventional therapeutic strategies for targeting advanced colorectal cancer by sensitizing CR-CSCs to chemotherapy and potentially reducing tumor recurrence.

The nervous system is the dominant regulatory system in the human body. The traditional theory is that tumors lack innervation. However, an increasing number of studies have shown complex bidirectional interactions between tumors and the nervous system. Globally, colorectal cancer (CRC) is the third most common cancer. With the rise of tumor neuroscience, the role of nervous system imbalances in the occurrence and development of CRC has attracted increasing amounts of attention. However, there are still many gaps in the research on the interactions and mechanisms involved in the nervous system in CRC. This article systematically reviews emerging research on the bidirectional relationships between the nervous system and CRC, focusing on the following areas: (1) Effects of the nervous system on colon cancer. (2) Effects of CRC on the nervous system. (3) Treatment of CRC associated with the nervous system.

Colorectal cancer (CRC) ranks as China's second most common cancer and fifth top cancer death cause. The study highlights the role of Natural Killer (NK) cells in targeting cancer stem cells (CSCs) that evade immune responses in CRC. Colorectal cancer stem cells (CCSCs) were stem from HT-29 cells and co-cultured with NK cells under normoxic or hypoxic conditions. The impact of this co-culture was evaluated using CCK8 assays for NK cell viability, ELISA for cytokine level changes, and flow cytometry for assessing NK cell apoptosis and activation. Comprehensive metabolomic and transcriptomic analyses were also performed to identify key genes and metabolites involved in the interaction between CCSCs and NK cells Co-culture of CCSCs with NK cells under hypoxia reduced NK cytotoxicity, increased NK apoptosis, and altered cytokine secretion by decreasing IFN-γ and TNF-α levels while increasing IL-6. Transcriptomic and metabolomic analysis identified 4 genes (FADS1, ALDH3A2, GCSH, MTCL1) and 3 metabolites (glyoxylic acid, spermine, DDA) as significant. Interfering with FADS1 counteracted the suppression of IFN-γ and TNF-α induced by CSC cells. Curiously, this inhibition caused by si-FADS1 could be neutralized by the addition of exogenous DDA. Co-culturing with NK cells notably increased spermine levels. Exogenous spermine resulted in a significant reduction in HT-29 cell death rates at 32 µM, 64 µM, and 128 µM, compared to NK cells without spermine. Our research explored CCSCs employed the FADS1/DDA axis to evade NK cell-mediated immunosuppression after co-cultured with NK cells under hypoxia.

Colorectal cancer (CRC) is the third diagnosed cancer worldwide. Forty-four percent of metastatic colorectal cancer patients were diagnosed at an early stage. Despite curative resection, approximately 40% of patients will develop metastases within a few years. Previous studies indicate the presence of cancer stem cells (CSCs) and their contribution to CRC progression and metastasis. miRNAs deregulation plays a role in CSCs formation and in tumor development. In light of previous studies, we investigated the role of miR-486-5p to understand its role in CSC better.

The expression of miR-486-5p was assessed in adherent cells and spheres generated from two CRC cell lines to observe the difference in expression in CSC-enriched spheroids. Afterward, we overexpressed and underexpressed this miRNA in adherent and sphere cultures through the transfection of a miR-486-5p mimic and a mimic inhibitor.

The results demonstrated that miR-486-5p exhibited a notable downregulation in CSC models, and its overexpression led to a significant decrease in colony size.

In this study, we confirmed that miR-486-5p plays an oncosuppressive role in CRC, thereby advancing our understanding of the role of this microRNA in the CSC phenotype.

Cancer remains a significant global challenge, and despite the numerous strategies developed to advance cancer therapy, an effective cure for metastatic cancer remains elusive. A major hurdle in treatment success is the ability of cancer cells, particularly cancer stem cells (CSCs), to resist therapy. These CSCs possess unique abilities, including self-renewal, differentiation, and repair, which drive tumor progression and chemotherapy resistance. The resilience of CSCs is linked to certain signaling pathways. Tumors with pathway-dependent CSCs often develop genetic resistance, whereas those with pathway-independent CSCs undergo epigenetic changes that affect gene regulation. CSCs can evade cytotoxic drugs, radiation, and apoptosis by increasing drug efflux transporter activity and activating survival mechanisms. Future research should prioritize the identification of new biomarkers and signaling molecules to better understand drug resistance. The use of cutting-edge approaches, such as bioinformatics, genomics, proteomics, and nanotechnology, offers potential solutions to this challenge. Key strategies include developing targeted therapies, employing nanocarriers for precise drug delivery, and focusing on CSC-targeted pathways such as the Wnt, Notch, and Hedgehog pathways. Additionally, investigating multitarget inhibitors, immunotherapy, and nanodrug delivery systems is critical for overcoming drug resistance in cancer cells.

Although the concept of cancer stem cells is still controversial, previous studies have shown that blood cancers, as well as specific types of solid cancers such as colorectal cancer, rely on stem cells during the onset of tumor growth and further tumor development. Moreover, resistance to therapeutic treatment in leukemias such as acute myeloid leukemia and in colorectal cancer can be attributed to a small population of cells with stemness properties known as minimal residual disease. In this review, we look back on the discovery of cancer stem cells and the contribution of the findings in blood cancer to a parallel discovery in solid cancers. We focus on CD44 as a stem cell marker, both in blood cancers and in several types of solid cancers, particularly of the gastrointestinal tract. This review highlights newly discovered molecular mechanisms of action of CD44 which indicate that CD44 has indeed a function in stemness, stem cell maintenance, and drug resistance. We attempt here to make the link between the functions of CD44 isoforms in stemness and their involvement in specific steps of tumor growth and metastasis.