Stem Cell-like Properties Research Articles

FBXO31-mediated ubiquitination of OGT maintains O-GlcNAcylation homeostasis to restrain endometrial malignancy

Protein O-GlcNAcylation is a post-translational modification coupled to cellular metabolic plasticity. Aberrant O-GlcNAcylation has been observed in many cancers including endometrial cancer (EC), a common malignancy in women. However, clinical characterization of dysregulated O-GlcNAcylation homeostasis in EC and interrogating its molecular mechanism remain incomplete. Here we report that O-GlcNAcylation level is positively correlated with EC histologic grade in a Chinese cohort containing 219 tumors, validated in The Cancer Genome Atlas dataset. Increasing O-GlcNAcylation in patient-derived endometrial epithelial organoids promotes proliferation and stem-like cell properties, whereas decreasing O-GlcNAcylation limits the growth of endometrial cancer organoids. CRISPR screen and biochemical characterization reveal that tumor suppressor F-box only protein 31 (FBXO31) regulates O-GlcNAcylation homeostasis in EC by ubiquitinating the O-GlcNAc transferase OGT. Downregulation of O-GlcNAcylation impedes EC tumor formation in mouse models. Collectively, our study highlights O-GlcNAcylation as a useful stratification marker and a therapeutic vulnerability for the advanced, poorly differentiated EC cases.

Dandelion extract suppresses the stem-like properties of triple-negative breast cancer cells by regulating CUEDC2/β-catenin/OCT4 signaling axis.

Triple-negative breast cancer (TNBC) represents the most aggressive subtype of breast cancer, featuring a high proportion of cancer stem cells (CSCs) and the poorest clinical outcomes. Taraxacum mongolicum Hand. -Mazz., widely recognized as dandelion, is a traditional medicinal herb that has demonstrated promising anti-TNBC potential. However, the efficacy of dandelion in anti-TNBC stem-like properties remains to be elucidated. The aim was to examine the impact of dandelion extract on the stemness properties of TNBC and to delineate the underlying mechanisms. UHPLC-Q-Orbitrap HRMS was employed to characterize the components present in dandelion extract. Network pharmacology was utilized to explore the impact of dandelion-derived compounds on the molecular pathways associated with TNBC. The assessment of TNBC stem-like properties was conducted through mammosphere formation assays and flow cytometry analysis. Western blotting, qRT-PCR, and immunofluorescence were employed to investigate the mechanisms of dandelion extract. 4T1-luc xenograft tumor model was used to assess the anti-tumor effect of dandelion extract in vivo. IVIS imaging technology was used to monitor lung metastasis. In this study, pharmacological network analysis revealed the potential regulatory effects of dandelion extract on TNBC stemness. Dandelion extract disrupts the stem-like properties in MDA-MB-231 and MDA-MB-468 cell lines via reducing ALDH+ cells proportion, impeding mammosphere formation, and downregulating CSC-related markers, including SOX2, SOX9, NANOG, and FOXM1. Furthermore, CUE domain containing protein 2 (CUEDC2) promotes the maintenance of TNBC stemness and contributes to the anti-stemness effects of dandelion extract. Mechanistically, dandelion extract inhibits CUEDC2-mediated nuclear translocation of β-catenin, thereby reducing the transcriptional activity of OCT4. In vivo, dandelion extract suppresses tumor growth, lung metastasis, and decreases the expression of CSC-related markers. These findings suggest that dandelion extract inhibits TNBC stem-like properties via modulating the CUEDC2/β-catenin/OCT4 signaling axis, highlighting its potential as a therapeutic option for TNBC.

Hypoxic Cancer Cells-Derived Exosomes Strengthen the Development of Cancer Stem Cell-Like Properties Through Delivering LINC00665 in Thyroid Cancer Cells.

Hypoxia is a common phenomenon for solid tumors due to a lack of effective vascular system, and has been deemed as an important factor that drives the progression of thyroid cancer (TC) via altering the characteristics of tumor cells. The present study suggested that hypoxic TC cells enhanced cancer stem cell properties and progression of TC by delivering long intergenic non-protein coding RNA 665 (LINC00665)-containing exosomes. Specifically, TPC1 cells were exposed to normoxic or hypoxic environment, and it was found that hypoxic TPC1 cells-secreted exosomes (H-exo) were enriched with LINC00665, compared to normoxic TPC1 cells-derived exosomes (N-exo). In addition, by establishing the in vitro exosomes-TC cells coculture system, we found that in contrast to N-exo, H-exo apparently promoted cell proliferation, epithelial mesenchymal transition (EMT) and cancer stem cell properties via delivering LINC00665. This was supported by the in vivo results that H-exo transferred LINC00665 to promote tumorigenesis and the expression of EMT and stemness-associated markers in xenograft tumor-bearing mice models. Further mechanical experiments validated that LINC00665 combined with EPHB4 mRNA to sustain its stability to enhance cancer aggressiveness of TC. Altogether, our findings verified that hypoxic TC cells-secreted exosomes regulated the LINC00665/EPHB4 axis to enhance cancer stem cell properties of TC, providing novel signatures for TC diagnosis and therapy.

The Multifaceted Roles of MicroRNA-181 in Stem Cell Differentiation and Cancer Stem Cell Plasticity.

Stem cells are undifferentiated or partially differentiated cells with an extraordinary ability to self-renew and differentiate into various cell types during growth and development. The epithelial-mesenchymal transition (EMT), a critical developmental process, enhances stem cell-like properties in cells, and is associated with both normal stem cell function and the formation of cancer stem cells. Cell stemness and the EMT often coexist and are interconnected in various contexts. Cancer stem cells are a critical tumor cell population that drives tumorigenesis, cancer progression, drug resistance, and metastasis. Stem cell differentiation and the generation of cancer stem cells are regulated by numerous molecules, including microRNAs (miRNAs). These miRNAs, particularly through the modulation of EMT-associated factors, play major roles in controlling the stemness of cancer stem cells. This review presents an up-to-date summary of the regulatory roles of miR-181 in human stem cell differentiation and cancer cell stemness. We outline studies from the current literature and summarize the miR-181-controlled signaling pathways responsible for driving human stem cell differentiation or the emergence of cancer stem cells. Given its critical role in regulating cell stemness, miR-181 is a promising target for influencing human cell fate. Modulation of miR-181 expression has been found to be altered in cancer stem cells' biological behaviors and to significantly improve cancer treatment outcomes. Additionally, we discuss challenges in miRNA-based therapies and targeted delivery with nanotechnology-based systems.

Betaine inhibits the stem cell-like properties of hepatocellular carcinoma by activating autophagy via SAM/m6A/YTHDF1-mediated enhancement on ATG3 stability.

Background: Stem cell-like properties are known to promote the recurrence and metastasis of hepatocellular carcinoma (HCC), contributing to a poor prognosis for HCC patients. Betaine, an important phytochemical and a methyl-donor related substance, has shown protective effects against liver diseases. However, its effect on HCC stem cell-like properties and the underlying mechanisms remains uninvestigated. Methods: We measured the effects of betaine on the stem cell-like properties and malignant progression of HCC using patient-derived xenografts, cell-derived xenografts, tail vein-lung metastasis models, in vitro limiting dilution, tumor sphere formation, colony formation, and transwell assays. Mechanistic exploration was conducted using western blots, dot blots, methylated RNA immunoprecipitation-qPCR, RNA stability assays, RNA immunoprecipitation-qPCR, RNA pull-down, and gene mutation assays. Results: A cohort study of HCC found that a higher serum concentration of betaine was associated with decreased levels of stemness-related markers. Furthermore, in HCC cells and xenograft mice, betaine suppressed the stem cell-like properties of HCC by activating autophagy. Mechanistically, betaine increased the m6A modification in HCC by producing S-adenosylmethionine (SAM) via betaine-homocysteine S-methyltransferase (BHMT). This increase in SAM subsequently triggered autophagy by enhancing the stability of autophagy-related protein 3 (ATG3) via YTHDF1 in an m6A-dependent manner, thereby inhibiting the stem cell-like properties of HCC cells. Conclusions: These findings indicate that betaine inhibits the stem cell-like properties of HCC via the SAM/m6A/YTHDF1/ATG3 pathway. This study underscores the potential anti-tumor effects of betaine on HCC and offers novel therapeutic prospects for HCC patients.

Doublecortin-like kinase 1 promotes stem cell-like properties through the Hippo-YAP pathway in prostate cancer.

Background: Doublecortin-like kinase 1 (DCLK1) has been revealed to be involved in modulating cancer stemness and tumor progression, but its role in prostate cancer (PCa) remains obscure. Castration-resistant and metastatic PCa exhibit aggressive behaviors, and current therapeutic approaches have shown limited beneficial effects on the overall survival rate of patients with advanced PCa. This study aimed to investigate the biological role and potential molecular mechanism of DCLK1 in the progression of PCa. Methods: The role of DCLK1 in maintaining PCa stem cell-like properties was explored via gain- and loss-of-function studies, including colony formation assays, sphere formation assays and measurement of stemness-related marker expression. A set of transcriptomic data for patients with PCa was downloaded from The Cancer Genome Atlas to analyze the correlations between DCLK1 and Hippo pathway gene expression. The mechanism by which DCLK1 regulates Hippo signaling and cancer stemness was further investigated in vitro by methods such as Western blot analysis, quantitative real-time PCR analysis, immunofluorescence staining, and luciferase reporter assays and in vivo by animal studies. Results: The gain- and loss-of-function studies demonstrated that upregulating DCLK1 promoted but downregulating DCLK1 suppressed aspects of the PCa stem cell-like phenotype, including colony formation, sphere formation and the expression of stemness-related markers (c-Myc, OCT4, CD44, NANOG, SOX2, and KLF4). Importantly, bioinformatics analysis indicated that DCLK1 is closely correlated with the Hippo signaling pathway in PCa. Further in vitro assays revealed that DCLK1 inhibits the Hippo signaling pathway, leading to yes-associated protein (YAP) activation via large tumor suppressor homolog 1 (LATS1). Moreover, the effect of DCLK1 on abolishing stemness traits in PCa was observed after treatment with verteporfin, a small molecule inhibitor of YAP. Consistent with the in vitro findings, the in vivo findings confirmed that DCLK1 promoted the tumorigenicity and stem cell-like traits of PCa cells via Hippo-YAP signaling. Conclusion: DCLK1 promotes stem cell-like characteristics by inducing LATS1-mediated YAP signaling activation, ultimately leading to PCa tumor growth and progression. Thus, our findings identify an attractive candidate for the development of cancer stem cell-targeted therapies to improve treatment outcomes in advanced PCa.

Effect of Pioglitazone and Cetuximab on Colon Cancer Stem-like Cell (CCSLCs) Properties.

One of the main reasons for cancer resistance to chemotherapy is the presence of cancer stem cells (CSCs) in cancer tissues. It is also believed that CSCs are the unique originators of all tumor cells. On the other hand, the Epithelial-Mesenchymal Transition pathway (EMT) can act as the main agent of metastasis. Therefore, it is possible that targeting CSCs as well as the EMT pathway could help in cancer therapy. Considering that CSCs constitute only a small percentage of the total tumor mass, enrichment before study is necessary. In our previous study, CSCs were enriched in the human colon cancer cell line HT29 by induction of EMT. These CSC-enriched HT29 cells with mesenchymal morphology were named "HT29-shE". In the present study, these cells were used to investigate the effect of pioglitazone (Pio) and Cetuximab (Cet) in order to find CSC and EMT targeting agents. The viability and IC50 rate of cells treated with different concentrations of Pio and Cet were evaluated using the MTT test. EMT and CSC markers and cell morphology were assessed in Pio and Cet treated and untreated HT29-shE cells using flow cytometry, realtime PCR, immunocytochemistry, and microscopic monitoring. The findings showed that Pio and Cet at concentrations of 250 μM and 40 μg/ml, respectively, decrease cell viability by 50%. Also, they were able to reduce the expression of CSC markers (CD133 and CD44) in the CSC enriched HT29 cell line. Furthermore, Pio and Cet could efficiently reduce the expression of vimentin as a mesenchymal marker and significantly upregulate the expression of E-cadherin as an epidermal marker of EMT and its reverse mesenchymal-- to-epithelial transition (MET). In addition, the mesenchymal morphology of HT29-shE changed into epithelial morphology after Cet treatment. Pio and Cet could inhibit EMT and reduce CSC markers in the EMT induced/CSC enriched cell line. We expect that focus on finding EMT/CSC-targeting agents like these drugs can be helpful for cancer treatment.

Ganglioside GD2 Contributes to a Stem-Like Phenotype in Intrahepatic Cholangiocarcinoma.

GD2, a member of the ganglioside (GS) family (sialic acid-containing glycosphingolipids), is a potential biomarker of cancer stem cells (CSC) in several tumours. However, the possible role of GD2 and its biosynthetic enzyme, GD3 synthase (GD3S), in intrahepatic cholangiocarcinoma (iCCA) has not been explored. The stem-like subset of two iCCA cell lines was enriched by sphere culture (SPH) and compared to monolayer parental cells (MON). GS profiles were evaluated by chromatography, after feeding with radioactive sphingosine. Membrane GD2 expression was evaluated by FACS, and the expression of enzymes of GS biosynthesis was analysed by RT-qPCR. The modulation of stem features by GS was investigated invitro and invivo using GD3S-overexpressing cells and corroborated by global transcriptomic analysis. GS composition was markedly different comparing SPH and MON. Among complex GS, iCCA-SPH showed increased GD2 levels, in agreement with the high expression levels of GD3 and GM2/GD2 synthases. iCCA cells overexpressing GD3S had higher sphere-forming ability, invasive properties and drug resistance than parental cells. NOD/SCID mice implanted with CCLP1 cells overexpressing GD3S developed larger tumours than control cells. By global transcriptomic analysis, ontology investigation identified 74 processes shared by the iCCA-SPH and GD3S-transfected cells, with enrichment for development and morphogenesis processes, MAPK signalling and locomotion. In a cohort of patients with iCCA, GD3S expression was correlated with lymph node invasion, indicating a possible relevance of GD3S in the clinical setting. The profile of GS derivatives regulates the stem-like properties of iCCA cells.

SNAI1 promotes epithelial-mesenchymal transition and maintains cancer stem cell-like properties in thymic epithelial tumors through the PIK3R2/p-EphA2 Axis

BackgroundThymic epithelial tumors (TETs) are infrequent malignancies that arise from the anterior mediastinum. Therapeutic options for TETs, especially thymic carcinoma (TC), remain relatively constrained. This study aims to investigate the oncogenic hub gene and its underlying mechanisms in TETs, as well as to identify potential therapeutic targets.MethodsWeighted gene co-expression network analysis (WGCNA) and differential gene expression (DEG) analysis were utilized to identify significant oncogenes using The Cancer Genome Atlas (TCGA) database. LASSO logistic regression analysis was performed to assess the association between hub genes and clinical parameters. The influence of the hub gene on promoting epithelial-mesenchymal transition (EMT), tumor progression, and regulating cancer stem cell-like properties was assessed both in vitro and in vivo. Single-cell RNA sequencing (scRNA-seq) was utilized to analyze the alterations in the tumor and its microenvironment following the administration of the hub gene’s inhibitor. Multiplex immunohistochemistry (mIHC) was employed to validate the results. The potential mechanism was further elucidated through the utilization of Cleavage Under Targets and Tagmentation (CUT&Tag), RNA-sequencing, chromatin immunoprecipitation (ChIP), CUT&RUN, luciferase reporter assay, co-immunoprecipitation (Co-IP), mass spectrometry (MS) and phosphoproteomic assays.ResultsSNAI1 was identified as a hub transcription factor for TETs, and its positive correlation with the invasiveness of the disease was confirmed. Subsequent experiments revealed that the upregulation of SNAI1 augmented the migration, invasion, and EMT of TET cell lines. Furthermore, we observed that the overexpression of SNAI1 sustained cancer stem cell-like properties. ScRNA-seq demonstrated that the use of a SNAI1 inhibitor inhibited the transition of macrophages from M1 to M2 phenotype, a finding further validated by multiplex immunohistochemistry (mIHC). Phosphoinositide-3-kinase regulatory subunit 2 (PIK3R2) was identified as one of the downstream targets of SNAI1 through CUT&Tag and RNA-sequencing, a finding validated by ChIP-qPCR, CUT&RUN-qPCR, luciferase reporter and immunofluorescence assays. Co-IP, MS and phosphoproteomic assays further confirmed that PIK3R2 directly interacted with phosphorylated EphA2 (p-EphA2), facilitating downstream GSK3β/β-catenin signaling pathway.ConclusionThe tumorigenic role of SNAI1 through the PIK3R2/p-EphA2 axis was preliminarily validated in TETs. A potential therapeutic strategy for TETs may involve the inhibition of SNAI1.

Tuft cells promote human intestinal epithelium regeneration as reserve stem cells after irradiation

Intestinal epithelium regeneration is crucial for homeostatic maintenance of the intestinal functions. A recent study published in Nature uncovers tuft cells as an unexpected key player in the regenerative process. Human tuft cells, traditionally recognized for their involvement in immune defense and pathogen protection, were found to exhibit stem cell-like properties following radiation-induced injury. These cells not only resist damage but also have the ability to generate functional stem cells, promoting the repair of the intestinal epithelium. This finding suggests that tuft cells may function as a reserve pool of stem cells, essential for efficient intestinal regeneration after injury.

Clinicopathological significance of SOX2 and FOXG1 expression patterns in ovarian immature teratomas

Objective: To investigate the relationship between the expression patterns of SOX2 and FOXG1 and the differentiation/development level of neural components in immature teratoma and to determine the clinical significance and potential application of this correlation in a clinical setting. Methods: We conducted a comprehensive whole transcriptome sequencing analysis to identify differentially expressed genes (DEGs) across various subtypes of ovarian germ cell tumors. Additionally, immunohistochemical staining of paraffin-embedded tissue sections was employed to assess the nuclear staining pattern of SOX2 and FOXG1 proteins within the tumor tissues. Results: The transcriptome sequencing data showed that transcription factors SOX2 and FOXG1 exhibited high levels of expression typically in immature teratoma and occupied a pivotal position within the protein-protein interaction network. Immunohistochemical staining revealed the absence of both SOX2 and FOXG1 protein expression in dysgerminoma and yolk sac tumor samples. In immature teratoma, immunohistochemical staining demonstrated diffuse expression of SOX2 and FOXG1 proteins within the inner layer of densely-arranged primitive neuroepithelial tubules. This pattern of expression suggested the presence of stem cell-like properties within these tumor cells. In the sparsely peripheral neurogliocytes, FOXG1 maintained a diffuse nuclear staining pattern resembling that of neuroepithelial cells, while SOX2 exhibited a scattered pattern of positive staining, hinting at a neural lineage differentiation potential. This spatial differential expression pattern of SOX2 and FOXG1 proteins in immature teratoma suggested that primitive neural components within these tumors often recapitulated the trajectory of neural formation and cortical development that was typically observed during embryogenesis. The primitive neural tube acted as the center that constantly moved from inside to outside, with a dynamic shift from the interior to the exterior, paralleled by the sequential differentiation of cell lineages from primitive neuroepithelial stem cells to radial glia, intermediate progenitor cells, and ultimately to precursor glia. Conclusions: This spatial expression pattern of SOX2 and FOXG1 proteins observed in immature teratoma mirrors the lineage differentiation and migration trajectories of primitive neuroepithelial components typically seen in embryonic neurogenesis and cortical development. In daily practice, the combined application of SOX2 and FOXG1 SOX2 and FOXG1 helps identify the primitive neuroepithelial components in immature teratoma, avoid misjudgment of similar morphologies, and thereby assist in the histological grading and clinical decision-making.

Profiling the extracellular vesicles of two human placenta-derived mesenchymal stromal cell populations.

Increasing evidence shows extracellular vesicles (EVs) are primarily responsible for the beneficial effects of cell-based therapies. EVs derived from mesenchymal stromal cells (MSCs) show promise as a source of EVs for cell-free therapies. The human placental fetal-maternal interface is a rich and abundant source of MSCs from which EVs can be isolated. This study focusses on chorionic MSCs (CMSC) located on the fetal aspect of the interface and decidual MSCs (DMSC) on the maternal aspect. This study used Ligand-based Exosome Affinity Purification (LEAP) chromatography to isolate EVs from well-characterized placental hTERT-transduced CMSC29 and DMSC23 cell lines, which retain many important stem cell-like properties of primary CMSC and DMSC, respectively. After initial biophysical characterization of the EVs isolated from each cell line, the biological activities and the protein, lipid and small RNA contents of CMSC29-EVs and DMSC23-EVs were compared and assessed. LEAP-purified EVs from both sources were validated at the biophysical level by Spectradyne, Cryo-Transmission Electron Microscopy (Cryo-TEM), and Western blot analysis. EVs from each type were labelled with the live cell stain PKH26 and their in vitro uptake and internalization by human dermal fibroblast cells was assessed, as well as their phosphorylation of the protein kinase B/AKT (AKT) pathway. The protein and lipid contents were analyzed by mass spectrometry and the nucleic acid content by RNA sequencing (RNA-seq). Lastly, the biological activities of the EVs were evaluated in a BioMAP® Diversity PLUS® screen system across a panel of 12 human primary cell-based systems and in vitro cell proliferation. EVs isolated from both DMSC23 and CMSC29 significantly increased proliferation of fibroblasts and showed phosphorylation of the AKT pathway. Protein mass spectrometry analysis identified a large number of proteins including cell surface receptors, cytokines, chemokines, matrix molecules and enzymes in both EV types. Lipidomic analysis identified species including phosphatidylcholine, triacylglycerides and diacylglycerides in both DMSC23 and CMSC29-derived EVs. There were some significant differences in identified microRNAs (miRNAs) between the two EV types. The top differentially expressed miRNAs between the two EV types show pathways association with matrix interaction, transcriptional regulation, proliferation, cellular protein modification processes, and vasculogenesis. Differences were also detected between DMSC23- and CMSC29-EVs in the biological activity they displayed in the BioMAP® Diversity PLUS® screen.

Hyaluronic acid-modified extracellular vesicles for targeted doxorubicin delivery in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), a prevalent and deadly cancer, poses a significant challenge with current treatments due to limitations such as poor stability, off-target effects, and severe side effects. Extracellular vesicles (EVs), derived from tumor cells, have the remarkable ability to home back to their cells of origin and can serve as Trojan horses for drug delivery. CD44, a cell surface glycoprotein, promotes cancer stem cell-like properties and is linked to poor prognosis and resistance to chemotherapy in HCC. Therefore, targeting CD44-expressing HCC cells is of interest in the development of novel therapeutic strategies for the treatment of HCC. In this study, we developed tumor cell-derived EVs (TEVs) functionalized with hyaluronic acid (HA) to serve as natural carriers for the precise delivery of doxorubicin (Dox), which specifically targets HCC cells expressing CD44. Our results demonstrated that HA-engineered EVs (HA-EVs) significantly enhanced Dox accumulation within HCC cells. In a mouse model, HA-EVs effectively delivered Dox to tumors, suppressing their growth and progression while minimizing systemic toxicity. This study demonstrates the potential of HA-functionalized EVs as a novel and targeted therapeutic platform for HCC, offering a valuable strategy for improving drug delivery and patient outcomes. This study presents a promising strategy to advance targeted chemotherapy for HCC and address the challenges associated with conventional treatments. Engineered HA-functionalized EVs offer a tailored and efficient approach to increase drug delivery precision, underscoring their potential as a novel therapeutic platform in the realm of HCC treatment.

Synthetic Retinoid Sulfarotene Selectively Inhibits Tumor-Repopulating Cells of Intrahepatic Cholangiocarcinoma via Disrupting Cytoskeleton by P-Selectin/PSGL1 N-Glycosylation Blockage.

Intrahepatic cholangiocarcinoma (ICC) is a highly lethal malignancy that currently lacks effective clinical treatments. Eliminating stem cell-like cancer cells is an extremely promising but challenging strategy for treating ICC. A recently developed synthetic retinoid, sulfarotene, abrogates proliferation, and induces apoptosis of tumor-repopulating cells (TRCs) that exhibit stem cell-like properties, yet its effect and underlying mechanisms remain elusive in ICC. It is found that although 5-fluorouracil, cisplatin, pemigatinib, and gemcitabine all inhibit ICC-TRCs, sulfarotene demonstrates superior efficacy. Sulfarotene induces retinoic acid receptor alpha (RARɑ) translocation from the cytoplasm to the nucleus, suppressing P-selectin expression at the transcriptional level. Moreover, it directly interacts with fucosyltransferase 8 (FUT8), inhibiting the core fucosylation of P-selectin glycoprotein ligand 1 (PSGL1). These actions collectively inhibit ICC-TRCs via destroying PSGL1-regulated cytoskeleton. The findings provide a strategy of inhibiting P-selectin/PSGL1 interaction and altering PSGL1 glycosylation pattern to compromise the cytoskeletal integrity and eliminate ICC-TRCs.

Stayin' Alive: Targeting Chromatin Regulators of Clonal Hematopoiesis Promotes CD8 T-cell Stemness.

T-cell exhaustion remains a significant barrier to immunotherapeutic success for many patients with solid tumors. Growing evidence suggests that enhanced survival and self-renewal properties of a stem-like precursor T-cell population are correlated with a survival advantage in immunotherapy. In a recent study published in Science, Kang and colleagues found that three epigenetic regulators commonly mutated in clonal hematopoiesis also control precursor T-cell progression to exhaustion. By leveraging the finding that patients with enhanced survival in myelodysplastic syndrome had T-cell mutations in the ASXL1 gene, this study demonstrates that loss of ASXL1 in T cells preserves their stem cell-like properties of self-renewal and survival, leading to increased antitumor responses when combined with immunotherapy in both mouse models and human cancers. These findings have significant implications for new therapeutic options that target epigenetic modifiers promoting exhaustion together with immune checkpoint blockade to improve response rates in patients.

USP5-dependent HDAC1 promotes cisplatin resistance and the malignant progression of non-small cell lung cancer by regulating RILP acetylation levels.

Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related deaths worldwide, with cisplatin (DDP) resistance being a significant challenge in its treatment. Histone deacetylase 1 (HDAC1) has been implicated in the regulation of NSCLC progression; however, its role in the resistance of NSCLC to DDP remains unclear. The mRNA levels of HDAC1, ubiquitin specific peptidase 5 (USP5), and Rab interacting lysosomal protein (RILP) were analyzed by quantitative real-time polymerase chain reaction. The protein expression of HDAC1, multidrug resistance protein 1 (MRP1) and RILP was detected by western blotting assay or immunohistochemistry assay. The IC50 value of DDP was determined using a cell counting kit-8 assay, while cell proliferation, apoptosis, and invasion were assessed using 5-Ethynyl-2'-deoxyuridine assay, flow cytometry, and trans well invasion assay, respectively. Cancer stem-like cell properties were analyzed by a sphere formation assay. The interaction between USP5 andHDAC1 was investigated using MG132 assay and co-immunoprecipitation (Co-IP).RILP acetylation was analyzed by a Co-IP assay. A xenograft mouse model assay was employed to study the in vivo effects of HDAC1 silencing on DDP sensitivity. HDAC1 expression was upregulated in DDP-resistant NSCLC tissues and cells. Silencing HDAC1 enhanced the sensitivity of NSCLC cells to DDP, inhibited cell proliferation, invasion, and the formation of microspheres and induced cell apoptosis. USP5 was found to deubiquitinate and stabilize HDAC1 in DDP-resistant NSCLC cells. Moreover, HDAC1 overexpression reversed the effects induced by USP5 silencing. HDAC1 also sensitized Rab-interacting lysosomal protein (RILP) acetylation in DDP-resistant NSCLC cells, and RILP upregulation counteracted the effects of HDAC1 overexpression in DDP-resistant NSCLC cells. HDAC1 silencing also improved the sensitivity of tumors to DDP in vivo. USP5-dependentstabilization of HDAC1 contributed to cisplatin resistance and the malignancy of NSCLC by diminishing the levels of RILP acetylation, which suggested that targeting the HDAC1-USP5axis might represent a novel therapeutic strategy for overcoming DDP resistance in NSCLC patients.

Myofibroblast-derived extracellular vesicles facilitate cancer stemness of hepatocellular carcinoma via transferring ITGA5 to tumor cells

BackgroundMyofibroblasts constitute a significant component of the tumor microenvironment (TME) and play a pivotal role in the progression of hepatocellular carcinoma (HCC). Integrin α5 (ITGA5) is a crucial regulator in myofibroblasts of malignant tumors. Therefore, the potential of ITGA5 as a novel target for the therapeutic strategy of HCC should be investigated.MethodsDigital scanning and analysis of the HCC tissue microarray were performed to locate the distribution of ITGA5 and conduct the prognosis analysis. CRISPR Cas9-mediated ITGA5 knockout was performed to establish the ITGA5-KO myofibroblast cell line. Extracellular vesicles (EVs) derived from LX2 were extracted for the treatment of HCC cells. Subsequently, the sphere-forming ability and the stemness markers expression of the treated HCC cells were examined. An orthotopic HCC mouse model with fibrotic injury was constructed to test the outcomes of ITGA5-targeting therapy and its efficacy in the programmed death-ligand 1 (PD-L1) treatment. Co-immunoprecipitation/mass spectrometry and transcriptome data were integrated to delve into the mechanism.ResultsThe tissue microarray results revealed that ITGA5 was highly enriched in the stromal myofibroblasts of HCC tissues and contributed to enhanced tumor progression and poor prognosis. Notably, ITGA5 transmission via extracellular vesicles (EVs) from myofibroblasts to HCC cells induced the acquisition of cancer stem cell-like properties. Mechanistically, ITGA5 directly bind to YES1, facilitating the activation of YES1 and its downstream pathways, thereby enhancing the stemness of HCC cells. Furthermore, the blockade of ITGA5 impeded tumor progression driven by ITGA5+ myofibroblasts and enhanced the efficacy of treatment with PD-L1 in a mouse model of HCC.ConclusionsOur findings elucidated a novel mechanism by which the EV-mediated transfer of ITGA5 from myofibroblasts to tumor cells augmented HCC stemness. ITGA5-targeting therapy helped prevent the progression of HCC and improved the efficacy of PD-L1 treatment.Graphical

BIOM-26. ROLE OF EXTRA-DOMAIN B FIBRONECTIN IN MODULATING GLIOBLASTOMA CELL INVASIVE PROPERTIES

Abstract Glioblastoma (GBM) is a highly malignant tumor characterized by its resistance to current treatment modalities and high recurrence rates. Extra-domain B Fibronectin (EDB-FN), a glycoprotein not found in normal tissues but selectively expressed in the tumor microenvironment, was previously identified by our team as a promising molecular marker for brain tumors, offering potential for both prognostic prediction and therapeutic targeting. However, the specific role and mechanism of action of EDB-FN in GBM cells remain unclear. In this study, we sought to elucidate the potential role of EDB-FN and the underlying mechanisms contributing to GBM malignancy through in vitro investigations. Our findings reveal that silencing EDB-FN in GBM cells leads to a decrease in cell migration, invasiveness, extracellular matrix adhesion ability, and stem cell-like properties. Furthermore, we discovered that FAK and ERK signaling pathways play a crucial role in GBM cell progression in response to EDB-FN. This study underscores the potential of EDB-FN as a specific biomarker for GBM treatment, paving the way for future research in this area.

Erratum: Stem Cell Protein PIWIL2 Promotes EMT Process and Stem Cell-Like Properties in MCF7 Breast Cancer Cell Line

Erratum: Stem Cell Protein PIWIL2 Promotes EMT Process and Stem Cell-Like Properties in MCF7 Breast Cancer Cell Line

Regulatory roles of NAMPT and NAD+ metabolism in uterine leiomyoma progression: Implications for ECM accumulation, stemness, and microenvironment

Uterine leiomyoma (UL), commonly referred to as benign tumors, is characterized by excessive cell proliferation, extracellular matrix (ECM) accumulation, and the presence of stem cell-like properties. Nicotinamide adenine dinucleotide (NAD+) metabolism, regulated in part by nicotinamide phosphoribosyltransferase (NAMPT), plays a crucial role in these pathological processes and has emerged as a potential therapeutic target. Additionally, redox signaling pathways are integral to the pathogenesis of UL, influencing the dynamics of NAD+ metabolism. This study sought to elucidate the regulatory functions of NAMPT and NAD+ metabolism, in conjunction with redox signaling, in the progression of UL, and to explore potential therapeutic strategies targeting these pathways. Evaluation of NAMPT expression in human UL tissues revealed a positive correlation between elevated NAMPT levels and increased ECM deposition, as well as the expression of stemness markers. The use of FK866 and nicotinamide (NAM), to inhibit NAMPT significantly suppressed UL cell viability and attenuated stem cell-like characteristics. Redox signaling pathways, including those associated with DNA damage, lysosomal function homeostasis, and redox-sensitive phagophore formation, were implicated in the regulation of ECM dynamics, particularly through ECM-targeted inhibition. This study highlights the pivotal roles of NAMPT, NAD+ metabolism, and redox signaling in the pathophysiology of UL. Targeting NAMPT, particularly through the use of inhibitors FK866 and NAM, represents a promising therapeutic approach for mitigating UL progression by modulating redox and ECM dynamics. These findings offer novel insights into UL pathogenesis and establish NAMPT as a compelling target for future clinical investigation.