Stem-like Properties Research Articles

Super-enhancer-hijacking RBBP7 potentiates metastasis and stemness of breast cancer via recruiting NuRD complex subunit LSD1

BackgroundAberrant epigenetic and transcriptional events that drive cancer progression could be precisely targeted. We aimed to uncover the epigenetic roles of RBBP7 on breast cancer (BCa) stemness and metastasis.MethodsThe bioinformatic analysis was used to assess the clinical significance of RBBP7 in BCa. CCK8, colony formation, and Transwell assays were utilized to estimate the oncogenic functions of RBBP7. The ChIP-qPCR and dual-luciferase reporter assays were used to investigate the epigenetic mechanisms of RBBP7. Tumor sphere formation assays were conducted to assess the self-renewal abilities of BCa cells. Tail vein injection models were constructed to assess the in vivo metastatic efficiency of BCa cells. The PDOs and PDX models were used to assess the clinical significance of ORY-1001 in suppressing BCa.ResultsHere, we found that RBBP7 is upregulated in BCa and associated with poor prognosis. Functional experiments demonstrated that RBBP7 enhanced BCa proliferation and distal metastasis. Mechanistically, a novel RBBP7-super-enhancer (SE) was identified using multiple databases in BCa. RBBP7-SE sustained high levels of RBBP7 and CRISPR/Cas9-mediated deletion of SE decreased RBBP7 levels and suppressed BCa malignant features. Further, our data showed that RBBP7 may correlate with stemness pathway and significantly potentiated BCa cancer stem-like properties. Additionally, RBBP7 interacts with LSD1 and relies on LSD1 to erase suppressive H3K9me3 markers in promoters of downstream stemness targets (SOX9/SOX2/OCT4/CCND1). Thus, RBBP7 recruits LSD1 to transcriptionally upregulate the expressions of key stemness genes, and promote tumor stemness capacity. Pharmacological inhibition of LSD1 by ORY-1001 effectively repressed RBBP7-high BCa tumor growth, stemness properties, and distant metastasis.ConclusionsTogether, our results establish that the SE-RBBP7-LSD1 axis represents a potential therapeutic target for BCa treatment.

Porphyromonas gingivalis potentiates stem-like properties of oral squamous cell carcinoma by modulating SCD1-dependent lipid synthesis via NOD1/KLF5 axis

Cancer stem cells (CSCs) are widely acknowledged as primary mediators to the initiation and progression of tumors. The association between microbial infection and cancer stemness has garnered considerable scholarly interest in recent years. Porphyromonas gingivalis (P. gingivalis) is increasingly considered to be closely related to the development of oral squamous cell carcinoma (OSCC). Nevertheless, the role of P. gingivalis in the stemness of OSCC cells remains uncertain. Herein, we showed that P. gingivalis was positively correlated with CSC markers expression in human OSCC specimens, promoted the stemness and tumorigenicity of OSCC cells, and enhanced tumor formation in nude mice. Mechanistically, P. gingivalis increased lipid synthesis in OSCC cells by upregulating the expression of stearoyl-CoA desaturase 1 (SCD1) expression, a key enzyme involved in lipid metabolism, which ultimately resulted in enhanced acquisition of stemness. Moreover, SCD1 suppression attenuated P. gingivalis-induced stemness of OSCC cells, including CSCs markers expression, sphere formation ability, chemoresistance, and tumor growth, in OSCC cells both in vitro and in vivo. Additionally, upregulation of SCD1 in P. gingivalis-infected OSCC cells was associated with the expression of KLF5, and that was modulated by P. gingivalis-activated NOD1 signaling. Taken together, these findings highlight the importance of SCD1-dependent lipid synthesis in P. gingivalis-induced stemness acquisition in OSCC cells, suggest that the NOD1/KLF5 axis may play a key role in regulating SCD1 expression and provide a molecular basis for targeting SCD1 as a new option for attenuating OSCC cells stemness.

Glycocalyx hyaluronan removal-induced increasing of cell stiffness delays breast cancer cells progression

Triple-negative breast cancer (TNBC) cells are rich in glycocalyx (GCX) that is closely correlated with the reorganization of cytoskeletal filaments. Most studies have focused on cell membrane glycoproteins in this context, but rarely on the significance of glycosaminoglycans, particularly the hyaluronan (HA)-associated GCX. Here, we reported that removal of GCX HA could significantly increase breast cancer cells (BCCs) stiffness, leading to impaired cell growth and decreased stem-like properties. Furthermore, we found that the delay of TNBC cells progression could be restored after the cells were re-softened. Meanwhile, in vivo studies revealed that hyaluronidase (HAase)-pretreated BCCs displayed reduced tumor growth and migration. Intriguingly, we identified that ZC3H12A, a zinc-finger RNA binding protein encoded gene, was significantly upregulated after the GCX HA impairment. Of note, knockdown of ZC3H12A could soften the HAase-treated TNBC cells, implying a GCX HA-ZC3H12A regulation on cell stiffening. Taken together, our findings suggested that the breakdown of pericellular HA coat could influence TNBC cells mechanical properties which might be helpful to the future breast cancer research.

Geniposide Inhibits Non-Small Cell Lung Cancer by Regulating Proliferation, Apoptosis, Invasion, Migration, Epithelial-Mesenchymal Transition, and Cancer Stem-Like Cell Property Via Wnt/β-Catenin Pathway.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer death worldwide. Geniposide, an active compound of Gardeniae Fructus, has antithrombotic, antitumor, neuroprotective, hepatoprotective, cholestatic, and other effects. The present study aimed to investigate the effects of geniposide on NSCLC cells, as well as its underlying mechanism. Two NSCLC cell lines (H1975 and A549) were treated with different doses of geniposide. The proliferation, apoptosis, migratory and invasive capacities, epithelial-mesenchymal transition (EMT), and stem cell characteristics of NSCLC cells were evaluated using a series of in vitro experiments, including colony formation, flow cytometry, wound healing, transwell, western blotting, and tube formations assays. H1975 cells were subcutaneously injected into nude mice to establish the xenograft tumor models, and the models were intraperitoneally injected with 100mg/kg geniposide or/and 6mg/kg SKL2001, an agonist of Wnt pathway. Immunohistochemistry, immunofluorescence, and western blotting analyses of the tumors were performed. Geniposide restrained the proliferation of NSCLC cells, as shown by reduced number of colonies and downregulation of Ki67 and PCNA expression levels. Geniposide promoted apoptosis by reducing Bcl-2 expression and increasing Bax expression. Additionally, geniposide inhibited the migratory and invasive abilities of NSCLC cells as well as reversed the EMT by downregulating vimentin, N-cadherin, snail, and slug and upregulating E-cadherin in the absence or presence of TGF-β1. Furthermore, geniposide attenuated the stem cell characteristics of NSCLC cells. In mechanism, geniposide repressed the activation of Wnt/β-catenin pathway. SKL2001 reversed the anti-NSCLC effects of geniposide in vitro. In the xenograft tumor models, 100mg/kg geniposide suppressed NSCLC tumor growth, which was reversed by SKL2001 treatment. Overall, geniposide inhibits NSCLC progression by reducing cancer cell proliferation, migration, invasiveness, EMT, and stem cell characteristics. This information might provide novel insights into the potential use of geniposide in lung cancer intervention.

Impact of G1 phase kinetics on the acquisition of stemness in cancer cells: the critical role of cyclin D.

Cancer stem cells (CSCs) represent a unique subpopulation of cells with the ability to self-renew and differentiate, thereby sustaining tumor growth and contributing to disease recurrence. Although CSCs predominantly reside in the G0 phase, their stem-like properties, such as the expression of specific CD markers, self-renewal, differentiation potential, tumor initiation, drug resistance, and increased invasive and metastatic potential, manifest during their active proliferative phase. Rapidly dividing cells exhibit alterations in their cell cycle, often characterized by shortened or bypassed G1 phases, a phenomenon observed in both embryonic stem cells and cancerous cells. Dysregulation of cell cycle control is a hallmark of cancer, leading to uncontrolled cellular proliferation and tumorigenesis. Disruption in key regulatory proteins, signaling pathways, and cell cycle checkpoints-particularly during the G1 phase-enables cancer cells to escape normal proliferation restrictions. The rapid cell-cycle progression can impair the timely degradation of proteins critical for cell cycle regulation, particularly cyclin D, thereby compromising proper cell cycle control. Therefore these proteins may be passed to daughter cells, promoting further rounds of rapid cycles. Additionally, cyclin D is often overexpressed in cancer cells, further exacerbating uncontrolled proliferation. These mechanisms may underpin key properties of CSCs, including rapid proliferation and their stem-like traits. This review examines the relationship between G1 phase kinetics and the acquisition of stem-like characteristics, emphasizing how rapid G1 phase progression and transitions between dormancy and active proliferation contribute to the emergence of CSC traits.

CD4 T cell depletion increases memory differentiation of endogenous and CAR T cells and enhances the efficacy of Super2 and IL-33-armored CAR T cells against solid tumors

BackgroundResponsiveness to chimeric antigen receptor (CAR) T cell therapy correlates with CAR T cell expansion and persistence in vivo. Multiple strategies improve persistence by increasing stem-like properties or sustaining CAR...

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.

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

The E2F4 transcriptional repressor is a key mechanistic regulator of colon cancer resistance to irinotecan (CPT-11).

Colorectal carcinomas (CRCs) are seldom eradicated by cytotoxic chemotherapy. Cancer cells with stem-like functional properties, often referred to as "cancer stem cells" (CSCs), display preferential resistance to several anti-tumor agents used in cancer chemotherapy, but the molecular mechanisms underpinning their selective survival remain only partially understood. In this study, we used Transcription Factor Target Genes (TFTG) enrichment analysis to identify transcriptional regulators (activators or repressors) that undergo preferential activation by chemotherapy in CRC cells with a "bottom-of-the-crypt" phenotype (EPCAM+/CD44+/CD166+; CSC-enriched) as compared to CRC cells with a "top-of-the-crypt" phenotype (EPCAM+/CD44neg/CD166neg; CSC-depleted). The two cell populations were purified in parallel by fluorescence-activated cell sorting (FACS) from a patient-derived xenograft (PDX) line representative of a moderately differentiated human CRC, following in vivo chemotherapy with irinotecan (CPT-11). The transcriptional regulators identified as differentially activated were tested for differential expression in normal vs. cancer tissues, and in cell populations enriched in stem/progenitor cell-types as compared to differentiated lineages (goblet cells, enterocytes) in the mouse colon epithelium. Finally, the top candidate was tested for mechanistic contribution to drug-resistance by selective down-regulation using short-hairpin RNAs (shRNAs). Our analysis identified E2F4 and TFDP1, two core components of the DREAM transcriptional repression complex, as transcriptional modulators preferentially activated by irinotecan in EPCAM+/CD44+/CD166+ as compared to EPCAM+/CD44neg/CD166neg cancer cells. The expression levels of both genes (E2F4, TFDP1) were found up-regulated in CRCs as compared to human normal colon tissues, and in a sub-population of mouse colon epithelial cells enriched in stem/progenitor elements (Epcam+/Cd44+/Cd66alow/Kitneg) as compared to other sub-populations enriched in either goblet cells (Epcam+/Cd44+/Cd66alow/Kit+) or enterocytes (Epcam+/Cd44neg/Cd66ahigh). Most importantly, E2F4 down-regulation using shRNAs dramatically enhanced the sensitivity of human CRCs to in vivo treatment with irinotecan, across three independent PDX models. Our data identified E2F4 and the DREAM repressor complex as critical regulators of human CRC resistance to irinotecan, and as candidate targets for the development of chemo-sensitizing agents.

TC2N maintains stem cell-like characteristics to accelerate lung carcinogenesis by blockade of dual specificity protein phosphatase 3

BackgroundTandem C2 domains, nuclear (TC2N) is a protein that has been characterized to contain C2A domain, C2B domain, and a short C-terminus with a WHXL motif. In previous studies, we have uncovered the oncogenic role and mechanisms of TC2N in lung cancer: TC2N achieves this by inhibiting the p53 signaling pathway and activating the NF-kappaB signaling pathway. Beyond that, its precise function in tumorigenesis is not fully understood.MethodsTC2N-engineered mice model was used to assess the effect of TC2N knockout on normal lung and urethane-induced carcinogenesis. Tumor tissues of 395 lung cancer patients were subjected to tissue microarray and further assessed the associations of TC2N expression with tumor differentiation degree. The protein levels of TC2N and stem cell markers in cell lines and tissue specimens were monitored by WB and immunohistochemistry. In vitro cell assays were performed to assess the effect of TC2N ectopic expression on the stem cell-like characteristics of lung cancer cells. The downstream signaling pathway or target molecule of TC2N was mined using a combination of transcriptomics and proteomics, and the underlying mechanism was explored by WB and co-IP assays.ResultsHerein, TC2N appeared to have a strong effect in promoting lung tumorigenesis caused by urethane, whereas it seemed to lose its function in the normal lung. Meanwhile, we found that the functional differences of TC2N between lung tumor and normal lung were linked to its potential role in cancer cell stemness. Function-wise, TC2N overexpression maintained stem-like properties of lung cancer cell. Mechanism-wise, TC2N upregulated the phosphorylation of EGFR, ERK, STAT3 and FAK1 to activate these signaling pathways by the inhibition of DUSP3 phosphatase via a dual mechanism. Firstly, TC2N competes with EGFR, ERK, STAT3 and FAK1 for binding to DUSP3. This competition prevents these signaling molecules from being dephosphorylated by DUSP3, resulting in their sustained activation. Secondly, TC2N bind to DUSP3 and restrict the enzyme’s ability to dephosphorylate the signaling molecules.ConclusionsOverall, this study revealed a previously unknown role and mechanism of TC2N in the regulation of tumorigenesis and stemness in lung cancer cells.

Relationship between transmembrane emp24 domain containing 2 expression and tumor stem cell characteristics in oral cancer.

Transmembrane Emp24 Domain Containing 2 (TMED2) is a mediator of membrane protein trafficking involved in intracellular protein transport. Recent research suggests that TMED2 plays an important role in the development and metastasis of tumors; however, its exact mechanisms in oral cancer (OC) remain unclear. This study aims to elucidate the role and possible mechanisms of TMED2 in OC. We investigated the impact of TMED2 knockdown on the invasion, migration, and proliferation capabilities of OC cells. Furthermore, we analyzed the in vitro and in vivo interactions between TMED2 and polypeptide-N-acetylgalactosaminyltransferase 7 (GALNT7) as well as explored the regulatory function of TMED2 on GALNT7. The alterations in stem cell markers were assessed using clone formation assays, western blot, and quantitative real-time polymerase chain reaction. The upregulation of TMED2 promoted the proliferation and invasion abilities of OC cells. Further analysis revealed that TMED2 enhanced the stem-like properties and tumorigenicity of OC cells by directly regulating the expression of GALNT7. In vivo and in vitro results suggested that silencing TMED2 expression reduced the incidence of OC. Our data imply that TMED2 stimulates GALNT7 transcription, which in turn amplifies the stem-like characteristics and carcinogenic potential of OC cells. Moreover, the block of TMED2 prevents cancers from growing and spreading in vivo. This finding provides a new therapeutic target for the treatment of OC and highlights the critical role of TMED2 in the condition.

Coupling of response biomarkers between tumor and peripheral blood in patients undergoing chemoimmunotherapy.

Coupling of response biomarkers between tumor and peripheral blood in patients undergoing chemoimmunotherapy.

USP14 modulates stem-like properties, tumorigenicity, and radiotherapy resistance in glioblastoma stem cells through stabilization of MST4-phosphorylated ALKBH5

USP14 modulates stem-like properties, tumorigenicity, and radiotherapy resistance in glioblastoma stem cells through stabilization of MST4-phosphorylated ALKBH5

Antibody/siRNA Nanocarriers Against Wnt Signaling Suppress Oncogenic and Stem-Like Behavior in Triple-Negative Breast Cancer Cells.

Triple-negative breast cancer (TNBC) is infamous for its aggressive phenotype and poorer prognosis when compared to other breast cancer subtypes. One factor contributing to this poor prognosis is that TNBC lacks expression of the receptors that available hormonal or molecular-oriented therapies attack. New treatments that exploit biological targets specific to TNBC are desperately needed to improve patient outcomes. One promising target for therapeutic manipulation is the Wnt signaling pathway, which has been associated with many invasive breast cancers, including TNBC. This pathway is activated in TNBC cells when extracellular Wnt ligands bind to overexpressed Frizzled7 (FZD7) transmembrane receptors, leading to downstream activation of intracellular β-catenin proteins. To target and inhibit Wnt signaling in TNBC cells, polymer nanoparticles (NPs) modified with anti-FZD7 antibodies and β-catenin small interfering RNAs (siRNAs) were developed, and their impact on the oncogenic behavior of treated TNBC cells was investigated. When compared to control NPs, the Wnt-targeted NPs induced greater levels of Wnt oncogene suppression. This led to greater inhibition of oncogenic and stem-like properties, including cell proliferation, drug resistance, and spheroid formation capacity. This work demonstrates a promising approach for targeting the Wnt pathway in TNBC to counter the cellular phenotypes that drive disease progression.

Molecular mechanisms driving lineage plasticity in prostate cancer: NANOG and beyond

Developing resistance to androgen receptor (AR) signaling inhibitors is a significant challenge in the treatment of castration-resistant prostate cancer. Prolonged use of inhibitors like enzalutamide can cause prostate cancer cells to undergo lineage reprogramming, transitioning to neuroendocrine subtypes that no longer rely on AR signaling. These neuroendocrine subtypes are among the most aggressive forms of prostate cancer. During this process of lineage plasticity, cancer cells experience extensive transcriptional rewiring and acquire stem-like properties characterized by increased stemness. Research has shown that prostate cancer cells gain these stem-like traits through the expression of stem cell-associated proteins such as NANOG, particularly under stable and accumulating conditions. The post-translational modification of NANOG at specific sites is critical for maintaining its stability, which in turn enhances the tumorigenic potential of the cells. This review discusses the mechanisms by which NANOG phosphorylation promotes stemness and lineage plasticity in prostate cancer.

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.

MicroRNA Profiling of PRELI-Modulated Exosomes and Effects on Hepatic Cancer Stem Cells.

The increasing incidence and mortality rates of liver cancer have heightened the demand for the development of effective anticancer drugs with minimal side effects. In this study, the roles of exosomes derived from liver cancer stem cells (LCSCs) with PRELI (Protein of Relevant Evolutionary and Lymphoid Interest) modulation and their miRNAs were investigated to explore their therapeutic properties for liver cancer. Various techniques, such as miRNA profiling, microRNA transfection, overexpression, flow cytometry, Western blotting, and immunocytochemistry, were used to evaluate the effects of exosomes under PRELI up- and downregulation. Downregulated PRELI cellular exosomes (DPEs) reduced the levels of five markers-CD133, CD90, CD24, CD13, and EpCAM-in LCSCs, with the exception of OV-6. Conversely, upregulated PRELI cellular exosomes (UPEs) significantly increased the expression of CD90, CD24, and CD133 in NHs, with the maximum increase in CD24. PRELI upregulation altered expression levels of miRNAs, including hsa-miR-378a-3p (involved in stem-like properties), hsa-miR-25-3p (contributing to cell proliferation), and hsa-miR-423-3p (driving invasiveness). Exosomes with downregulated PRELI inhibited the AKT/mTORC1 signaling pathway, whereas LCSCs transfected with the candidate miRNAs activated it. Additionally, under PRELI upregulation, exosomes showed increased surface marker expression, promoting cancer progression. The modulation of PRELI in LCSCs affected miRNA expression significantly, revealing candidate miRNA targets for liver cancer treatment. Exosomes with PRELI downregulation show potential as a novel therapeutic strategy. Consequently, this study proposes the potential of PRELI-induced exosomes and the three miRNAs as a liver anticancer therapeutic candidate.

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.

Rhaponticin suppresses the stemness phenotype of gastric cancer stem-like cells CD133+/CD166 + by inhibiting programmed death-ligand 1

BackgroundGastric cancer stem cells (GCSCs) are key contributors to tumorigenesis, recurrence and metastasis, complicating gastric cancer (GC) treatment. Rhaponticin (RA), a potential novel anticancer drug, has unexplored effects on GCSCs.MethodsGCSCs were isolated using CD133 and CD166 markers with magnetic bead separation method and then evaluated their response to the IC50 concentrations of RA (16.90 µg/mL for BGC-823 and 22.18 µg/mL for SGC-7901), and effects on cell proliferation, migration, invasion, and stemness were measured. We analyzed the GCSC-related microarray dataset GSE111556 and explored RA’s role in restoring programmed cell death ligand 1 (PD-L1) function in CD133+/CD166 + cells post-PD-L1 knockdown. RA’s impact on tumour growth and immune microenvironment was assessed in a xenograft mouse model.ResultsThe CD133+/CD166 + subpopulation exhibited stem-like characteristics, with the highest proportion in BGC-823 (38.85%) and SGC-7901 (43.81%) cells. These cells formed tumour spheres and had increased expression of stemness markers Sox2 and Oct-4 (compared to the parental cell line, P < 0.001). RA treatment showed no toxicity to normal GES-1 cells but reduced the viability of CD133+/CD166 + cells in a dose-dependent manner, with IC50 values of 16.90 µg/ml for BGC-823 and 22.18 µg/ml for SGC-7901. RA also decreased the proportion of CD133+/CD166 + cells and their stem-like properties (P < 0.001). Analysis of the GEO database identified PD-L1 as a key target gene of RA, with high expression in GC tissues. Knocking down PD-L1 in CD133+/CD166 + cells and introducing RA did not significantly change PD-L1 expression (P>0.05), suggesting RA’s effect may be PD-L1 dependent. In a xenograft mouse model, the tumour size in the RA treatment group was approximately one-sixth that of the CD133+/CD166 + group (P < 0.001). Post-RA treatment, there was an elevation in the expression levels of CD4 and CD8, alongside a reduction in PD-L1 expression (P < 0.001).ConclusionsRA suppresses GCSC stem - like phenotype by inhibiting PD - L1 and enhancing T cell tumour infiltration in the studied models. These findings suggest that RA may have potential for further exploration as a candidate for GC treatment, but extensive preclinical and clinical studies are required to determine its true therapeutic value.

Micropapillary structure: A natural tumor collective invasion model with enhanced stem-like properties.

Cancer stem cells aggregate to form clusters, which have enhanced stem-like properties and metastasis potential. However, the molecular mechanisms underlying the formation of cancer stem cell cluster-like structures with acquisition of stronger invasion and metastasis abilities remain unclear. Micropapillary carcinoma (MPC) is a subpopulation of small, merulioid, inverted, nonfibrous vascular clusters floating in the stroma present in a range of solid malignant tumors and characterized by frequent vascular/lymphatic vessel invasion and lymph node metastasis. Our results showed that these cell clusters exhibit a stem cell phenotype, supporting the premise that MPC may serve as a promising solid tumor model for studying invasion and metastasis of cancer stem cell clusters. In this review, we discuss the latest advances in MPC research and targeted therapy, focusing on analysis of their stem-like characteristics, mapping their multiomics characteristics, and elucidating the vascular and immune microenvironment of MPC. The existing MPC organoid model was employed to explore potential breakthroughs in targeted therapy and immunotherapy for cancer stem cell clusters.