Sphere Formation Assay Research Articles

Mesenchymal stem cell-derived exosomes carrying miR-486-5p inhibit glycolysis and cell stemness in colorectal cancer by targeting NEK2.

Colorectal cancer (CRC) is a major global concern. Mesenchymal stem cell-derived exosomes (MSC-EXOs) have demonstrated efficacy as a therapeutic approach for colorectal cancer. However, the precise mechanism by which MSC-EXOs treat colorectal cancer remains unclear. Human umbilical cord (hUC)-MSC-EXOs were isolated and identified. Cell Counting Kit-8 (CCK-8), Transwell, and colony formation assays were used to assess the activity of CRC cells. Glucose consumption, lactic acid production, and extracellular acidification rate (ECAR) were measured to assess glycolytic activity. Cell stemness was assessed using a sphere-formation assay. Furthermore, MSC-exosomal microRNAs (miRNAs) in CRC tissues were analyzed using the EVmiRNA database, and aberrantly expressed miRNAs in CRC cells were obtained from the Gene Expression Omnibus (GEO) database. The binding relationship between miR-486-5p and the never in mitosis gene A-related kinase 2 (NEK2) was predicted using the Starbase database and validated through RNA binding protein immunoprecipitation (RIP) and dual luciferase assays. These results showed that hUC-MSC-EXOs inhibited the proliferation and metastasis of CRC cells. Moreover, glycolysis and stemness abilities of CRC cells also decreased after treatment with hUC-MSC-EXOs. miR-486-5p was found to be enriched in hUC-MSC-EXOs and significantly downregulated in CRC cells. miR-486-5p directly bound to NEK2. Overexpression of NEK2 reversed the inhibitory effect of miR-486-5p on CRC cell glycolysis and stemness. Our study highlights that hUC-MSC-EXO miR-486-5p inhibits glycolysis and cell stemness in CRC by targeting NEK2. This finding offers compelling evidence supporting the potential application of hUC-MSC-EXOs in the treatment of CRC.

Shikonin Stimulates Mitochondria-Mediated Apoptosis by Enhancing Intracellular Reactive Oxygen Species Production and DNA Damage in Oral Cancer Cells.

Phytotherapy has rendered a new insight towards the treatment of various cancers, including oral cancer with fewer side effects, over the traditional chemotherapeutic drugs to overcome chemoresistance. Shikonin (Shk) is a natural biologically active alkaloid found in the Lithospermum erythrorhizon plant's root. It has potent cytotoxic activities against various cancers. Our study revealed the release time and anticancer potential of Shk on the SCC9 and H357 oral cancer cell lines. We investigated the antiproliferative, antimigratory, cell cycle arresting and apoptosis promoting activity of Shk in oral cancer cells by performing MTT and morphological assay, colony, and tumor sphere formation assay, AO/EtBr and DAPI staining, Annexin V-FITC/PI staining, assay for reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) measurement, comet assay, qRT-PCR, and western blot analysis. We also checked the interaction of DNA and Shk by docking and CD spectroscopy and EtBr displacement assay. As a result, we found that Shk reduced the viability, proliferation, and tumorigenicity of SCC9 and H357 cells in a time and concentration-dependent manner. We obtained half-maximal inhibitory concentration (IC50) at 0.5 µM for SCC9 and 1.25 µM for H357. It promotes apoptosis via overexpressing proapoptotic Bax and caspase 3 via enhancing ROS that leads to MMP depletion and DNA damage and arrests cells at the G2/M & G2/S phase. The antimigratory activity of Shk was performed by analyzing the expression of markers of epithelial-mesenchymal transition like E-cadherin, ZO-1, N-cadherin, and vimentin. These overall results recommended that Shk shows potent anticancer activity against oral cancer cell lines in both in vitro and ex vivo conditions. So, it could be an excellent agent for the treatment of oral cancer.

PDGFRB promotes dedifferentiation and pulmonary metastasis through rearrangement of cytoskeleton under hypoxic microenvironment in osteosarcoma

BackgroundOsteosarcoma (OS) cells commonly suffer from hypoxia and dedifferentiation, resulting in poor prognosis. We plan to identify the role of hypoxia on dedifferentiation and the associated cellular signaling. MethodsWe performed sphere formation assays and determined spheroid cells as dedifferentiated cells by detecting stem cell-like markers. RNAi assay was used to explore the relationship between hypoxia inducible factor 1 subunit alpha (HIF1A) and platelet derived growth factor receptor beta (PDGFRB). We obtained PDGFRB knockdown and overexpression cells through lentiviral infection experiments and detected the expression of PDGFRB, p-PDGFRB, focal adhesion kinase (FAK), p-FAK, phosphorylated myosin light chain 2 (p-MLC2), and ras homolog family member A (RhoA) in each group. The effects of PDGFRB on cytoskeleton rearrangement and cell adhesion were explored by immunocytochemistry. Wound-healing experiments, transwell assays, and animal trials were employed to investigate the effect of PDGFRB on OS cell metastasis both in vitro and in vivo. ResultsDedifferentiated OS cells were found to exhibit high expression of HIF1A and PDGFRB, and HIF1A upregulated PDGFRB, subsequently activated RhoA, and increased the phosphorylation of MLC2. PDGFRB also enhanced the phosphorylation of FAK. The OS cell morphology and vinculin distribution were altered by PDGFRB. PDGFRB promoted cell dedifferentiation and had a significant impact on the migration and invasion abilities of OS cells in vitro. In addition, PDGFRB increased pulmonary metastasis of OS cells in vivo. ConclusionOur results demonstrated that HIF1A up-regulated PDGFRB under hypoxic conditions, and PDGFRB regulated the actin cytoskeleton, a process likely linked to the activation of RhoA and the phosphorylation of, thereby promoting OS dedifferentiation and pulmonary metastasis.

Non-glycanated ΔDCN isoform in muscle invasive bladder cancer mediates cancer stemness and gemcitabine resistance.

The small leucine-rich proteoglycan decorin (DCN) is recognized for its diverse roles in tissue homeostasis and malignant progression. Nevertheless, the regulatory effects of DCN on bladder cancer stem cells (BCSCs) and the underlying mechanisms in muscle-invasive bladder cancer (MIBC) remain to be elucidated. The study obtained data (including scRNA-seq, clinicopathological characteristics, and survival) were acquired from TCGA and GEO. The BCSCs were cultured by enriching the suspension culture in a serum-free medium, followed by flow cytometry sorting. Overexpression/knockdown was constructed by utilizing lentivirus. The surface biomarkers of cancer stem cells were identified via flow cytometry. Cell proliferation and self-renewal were evaluated by CCK8 and Sphere formation assays, and in vivo tumor growth was evaluated with subcutaneous xenografts. Total DCN expression was significantly elevated in muscle-invasive bladder cancer (MIBC) and was associated with poor prognosis. The ΔDCN isoform, which lacks glycosylation sites, was identified in bladder cancer stem cells (BCSCs) derived from clinical tissue samples and bladder cancer cell lines. Suppression of ΔDCN expression resulted in a reduction of BCSC stemness. Both in vitro and in vivo experiments indicated that overexpression of full-length DCN inhibited stemness within the extracellular matrix. Conversely, overexpression of ΔDCN and the introduction of exogenous recombinant decorin protein in ΔDCN-knockdown BCSC-SW780 cell lines enhanced stemness within the cytoplasm. The ΔDCN isoform exhibited resistance to gemcitabine chemotherapy in vitro. Non-glycanated ΔDCN isoforms were identified in bladder cancer stem cells (BCSCs), where they exhibited differential cytoplasmic localization and promoted oncogenic effects by inducing a stemness phenotype and conferring resistance to gemcitabine chemotherapy. These oncogenic effects are in stark contrast to the anti-tumor functions of glycosylated DCN in the extracellular matrix. The ratio of ΔDCN isoforms to glycosylated DCN is pivotal in predicting tumor progression and therapeutic resistance.

MiR-124-3p inhibits cell stemness in glioblastoma via targeting EPHA2 through ALKBH5-mediated m6A modification.

Glioblastoma (GBM) is the most aggressive form of glioma, characterized by high mortality and poor prognosis. Dysregulation of microRNAs (miRNAs) plays a critical role in the progression and metastasis of GBM. This study aimed to investigate the role and molecular mechanism of miR-124-3p in GBM. Levels of miR-124-3p, EPHA2, and ALKBH5 were measured using quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation, migration, invasion, and stemness were assessed using the Cell Counting Kit-8 (CCK-8), colony formation, Transwell, and sphere formation assays, respectively. Bioinformatics prediction, dual-luciferase reporter assays, and RNA pull-down experiments were employed to validate the target of miR-124-3p. RNA binding protein immunoprecipitation (RIP) and methylated RNA immunoprecipitation (Me-RIP) were utilized to evaluate the regulation of miR-124-3p maturation by ALKBH5. The results indicated that overexpression of miR-124-3p inhibited the proliferation, migration, invasion, and stemness of GBM cells. EPHA2 was identified as a direct downstream target of miR-124-3p, and its overexpression reversed the inhibitory effects of miR-124-3p on cellular functions. Furthermore, miR-124-3p targeted EPHA2 to inactivate the Wnt/β-catenin pathway. Additionally, ALKBH5 negatively regulated miR-124-3p by impeding its processing. In conclusion, knockdown of ALKBH5 promoted the processing of pri-miR-124-3p, increasing mature miR-124-3p levels, which inhibited the malignant behaviors of GBM cells by targeting EPHA2. These findings highlight the importance of the ALKBH5/miR-124-3p/EPHA2 axis in GBM.

Transcription factor YY1-activated GNG5 facilitates glioblastoma cell growth, invasion, stemness and glycolysis through Wnt/β-catenin pathway

G protein subunit Gamma 5 (GNG5) has been found to be involved in regulating glioma progression. However, its function and mechanism in glioblastoma (GBM) progression need to be further elucidated. GBM cell proliferation, apoptosis, invasion and stemness were assessed by cell counting kit 8 assay, EdU assay, flow cytometry, transwell assay and sphere formation assay. The mRNA and protein levels of GNG5 and Yin Yang 1 (YY1) were determined by quantitative real-time PCR and western blot (WB). Detection of the glucose consumption, lactate production and ATP/ADP ratios were used to assess cell glycolysis. Besides, Wnt/β-catenin pathway-related protein levels were examined by WB. Mice xenograft model was also constructed to explore GNG5 roles in vivo. GNG5 was highly expressed in GBM, and its silencing inhibited GBM cell proliferation, invasion, stemness and glycolysis, while promoted apoptosis. Transcription factor YY1 could bind to the GNG5 promoter region and induce its expression. GNG5 overexpression reversed the inhibitory effects of YY1 silencing on GBM cell growth, invasion, stemness and glycolysis. YY1/GNG5 axis could activate the Wnt/β-catenin pathway, and Wnt/β-catenin pathway agonists SKL2001 could revert the effects of GNG5 silencing on GBM cell progression. Furthermore, GNG5 facilitated GBM tumor growth by mediating the Wnt/β-catenin pathway. YY1-mediated GNG5 promoted GBM progression through the Wnt/β-catenin pathway.

FBW7-Mediated Degradation of CHD3 Suppresses Hepatocellular Carcinoma Metastasis and Stemness to Enhance Oxaliplatin Sensitivity.

Ubiquitination plays a key role in various cancers, and F-box and WD repeat domain containing 7 (FBW7) is a tumor suppressor that targets several cancer-causing proteins for ubiquitination. This paper set out to pinpoint the role of FBW7 in hepatocellular carcinoma (HCC). The target proteins of FBW7 and the expression of hromodomain helicase DNA binding protein 3 (CHD3) were analyzed in liver HCC (LIHC) samples using the BioSignal Data website. The effects of CHD3 and FBW7 on HCC cell viability, migration, invasion and stemness were investigated through cell counting kit (CCK)-8, wound healing, transwell and sphere formation assays. Detection on CHD3 and FBW7 expressions as well as their relationship was performed employing quantitative reverse transcription-polymerase chain reaction (qRT-PCR), immunoprecipitation, ubiquitination and western blot analyses. The prediction of Ubibrowser revealed CHD3 as a target protein of FBW7. The data of starBase exhibited a higher expression level of CHD3 in LIHC samples relative to normal samples. CHD3 was upregulated in HCC cells. CHD3 knockdown inhibited HCC cell proliferation, migration, invasion, stemness and oxaliplatin sensitivity. FBW7 targeted CHD3 for ubiquitination. FBW7 overexpression restrained HCC cell migration, invasion and stemness, and attenuated the effects of overexpressed CHD3 on promoting migration, invasion, stemness and oxaliplatin resistance in HCC cells. FBW7 overexpression suppresses HCC cell metastasis, stemness and oxaliplatin resistance via targeting CHD3 for ubiquitylation and degradation.

Effects of BYL-719 (alpelisib) on human breast cancer stem cells to overcome drug resistance in human breast cancer.

Breast cancer continues to be a major health concern and is currently the most commonly diagnosed cancer worldwide. Relapse, metastasis, and therapy resistance are major clinical issues that doctors need to address. We believe BYL-719, which is PI3 kinase p110а inhibitor, could also inhibit the breast cancer stem cell phenotype and epithelial-to-mesenchymal transition (EMT). In addition to the PI3K/AKT signaling pathway, BYL-719 can also inhibit essential cancer-related signaling pathways, all of which would ultimately act on the microenvironment of cancer stem cells, which is quite complicated and regulates the characteristics of tumors. These include the stemness and resistance of malignant tumors, plasticity of cancer stem cells, and anti-apoptotic features. A three-dimensional (3D) mammosphere culture method was used in vitro to culture and collect breast cancer stem cells (BCSCs). MTT, clonogenic, and cell apoptosis assays were used to detect cell viability, self-renewal, and differentiation abilities. A sphere formation assay under 3D conditions was used to detect the mammophore inhibition rate of BYL-719. The subpopulation of CD44+CD24- was detected using flow cytometry analysis while EMT biomarkers and essential signaling pathways were detected using western blotting. All the data were analyzed using GraphPad Prism 9 software. BCSC-like cells were obtained by using the 3D cell culture method in vitro. We confirmed that BYL-719 could inhibit BCSC-like cell proliferation in 3D cultures and that the stemness characteristics of BCSC-like cells were inhibited. The PI3K/AKT/mTOR signaling pathway could be inhibited by BYL-719, and the Notch, JAK-STAT and MAPK/ERK signaling pathways which have crosstalk in the tumor microenvironment (TME) are also inhibited. By comparing eribulin-resistant breast cancer cell lines, we confirmed that BYL-719 could effectively overcome drug resistance. The 3D cell culture is a novel and highly effective method for enriching BCSCs in vitro. Furthermore, the stemness and EMT of BCSCs were inhibited by BYL-719 by acting on various signaling pathways. Finally, we believe that drug resistance can be overcome by targeting the BCSCs. Conjugation of BYL-719 with other anti-neoplastic agents may be a promising treatment for this in clinic.

The NEDD4/FLRT2 axis regulates NSCLC cell stemness.

Lung cancer is the leading cause of cancer-related death worldwide. The treatment for lung cancer, particularly for non-small cell lung cancer (NSCLC), remains a clinical challenge. Cancer stem cells are vital for lung cancer development. This study aimed to determine the influence of the neuronally expressed developmentally downregulated 4-fibronectin leucine-rich transmembrane 2 (NEDD4-FLRT2) axis on cancer cell stemness in NSCLC. FLRT2 expression in NSCLC tissues and stem cells was investigated using western blot and RT-qPCR. The sphere formation assay and the abundance of stemness markers were employed to confirm the stemness of NSCLC stem cells. The CCK-8, colony formation, and Trans-well assays, as well as flow cytometry, were used to determine NSCLC stem cell growth, metastasis, and apoptosis, respectively. The Co-IP assay was used to confirm the binding between NEDD4 and FLRT2. Xenograft tumor mouse models were used to investigate tumorigenesis in vivo. Here, we reported that FLRT2 expression was reduced in NSCLC tissues, cells, and NSCLC stem cells. FLRT2 upregulation inhibited NSCLC stem cell proliferation, sphere formation, and drug resistance and promoted drug-resistant cell apoptosis. Furthermore, FLRT2 overexpression demonstrated antitumor effects in a xenograft tumor mouse model. Mechanically, FLRT2 was ubiquitinated and degraded by E3 ligase NEDD4. NEDD4 overexpression significantly abolished the inhibitory effects of FLRT2 on NSCLC stemness, as evidenced by in vitro and in vivo experiments. This study revealed that FLRT2 acted as a tumor suppressor by inhibiting cancer cell stemness in NSCLC. NEDD4 promoted ubiquitination degradation of FLRT2 protein. NEDD4 counteracted the inhibitory effects of FLRT2 on NSCLC stem cell tumorigenesis.

Integrated multi-omics analysis of PBX1 in mouse adult neural stem- and progenitor cells identifies a transcriptional module that functionally links PBX1 to TCF3/4.

Developmental transcription factors act in networks, but how these networks achieve cell- and tissue specificity is still poorly understood. Here, we explored pre-B cell leukemia homeobox 1 (PBX1) in adult neurogenesis combining genomic, transcriptomic, and proteomic approaches. ChIP-seq analysis uncovered PBX1 binding to numerous genomic sites. Integration of PBX1 ChIP-seq with ATAC-seq data predicted interaction partners, which were subsequently validated by mass spectrometry. Whole transcriptome spatial RNA analysis revealed shared expression dynamics of Pbx1 and interacting factors. Among these were class I bHLH proteins TCF3 and TCF4. RNA-seq following Pbx1, Tcf3 or Tcf4 knockdown identified proliferation- and differentiation associated genes as shared targets, while sphere formation assays following knockdown argued for functional cooperativity of PBX1 and TCF3 in progenitor cell proliferation. Notably, while physiological PBX1-TCF interaction has not yet been described, chromosomal translocation resulting in genomic TCF3::PBX1 fusion characterizes a subtype of acute lymphoblastic leukemia. Introducing Pbx1 into Nalm6 cells, a pre-B cell line expressing TCF3 but lacking PBX1, upregulated the leukemogenic genes BLK and NOTCH3, arguing that functional PBX1-TCF cooperativity likely extends to hematopoiesis. Our study hence uncovers a transcriptional module orchestrating the balance between progenitor cell proliferation and differentiation in adult neurogenesis with potential implications for leukemia etiology.

Inhibition of EREG/ErbB/ERK by Astragaloside IV reversed taxol-resistance of non-small cell lung cancer through attenuation of stemness via TGFβ and Hedgehog signal pathway.

Taxol is the first-line chemo-drug for advanced non-small cell lung cancer (NSCLC), but it frequently causes acquired resistance, which leads to the failure of treatment. Therefore, it is critical to screen and characterize the mechanism of the taxol-resistance reversal agent that could re-sensitize the resistant cancer cells to chemo-drug. The cell viability, sphere-forming and xenografts assay were used to evaluate the ability of ASIV to reverse taxol-resistance. Immunohistochemistry, cytokine application, small-interfering RNA, small molecule inhibitors, and RNA-seq approaches were applied to characterize the molecular mechanism of inhibition of epiregulin (EREG) and downstream signaling by ASIV to reverse taxol-resistance. ASIV reversed taxol resistance through suppression of the stemness-associated genes of spheres in NSCLC. The mechanism exploration revealed that ASIV promoted the K48-linked polyubiquitination of EREG along with degradation. Moreover, EREG could be triggered by chemo-drug treatment. Consequently, EREG bound to the ErbB receptor and activated the ERK signal to regulate the expression of the stemness-associated genes. Inhibition of EREG/ErbB/ERK could reverse the taxol-resistance by inhibiting the stemness-associated genes. Finally, it was observed that TGFβ and Hedgehog signaling were downstream of EREG/ErbB/ERK, which could be targeted using inhibitors to reverse the taxol resistance of NSCLC. These findings revealed that inhibition of EREG by ASIV reversed taxol-resistance through suppression of the stemness of NSCLC via EREG/ErbB/ERK-TGFβ, Hedgehog axis.

Multi-omics analysis unveils the predictive value of IGF2BP3/SPHK1 signaling in cancer stem cells for prognosis and immunotherapeutic response in muscle-invasive bladder cancer

BackgroundMuscle invasive bladder cancer (MIBC) is a life-threatening malignant tumor characterized by high metastasis rates, poor prognosis, and limited treatment options. Immune checkpoint inhibitors (ICIs) targeting PD-1 and PD-L1 represent an emerging treatment for MIBC immunotherapy. However, the characteristics of patients likely to benefit from immunotherapy remain unclear.MethodsWe performed single-cell mass cytometry (CyTOF) analysis of 179,483 single cells to characterize potential immunotherapy-related cancer stem cells (CSCs)-like populations in the tumor microenvironment of 38 MIBC tissues. The upregulated expression of IGF2BP3 in CD274 + ALDH + CSC-like cells, which was associated with poor clinical prognosis, was analyzed by bulk RNA-sequencing data from an in-house cohort. The functional role of IGF2BP3 was determined through cell proliferation, colony formation, cell apoptosis and sphere formation assays. The regulation of SPHK1 expression by IGF2BP3 was investigated using methylated RNA immunoprecipitation sequencing (MeRIP-seq) and bulk RNA-sequencing (bulk RNA-seq). We further utilized single-nucleus RNA sequencing (snRNA-seq) data from 67,988 cells of 25 MIBC tissues and single-cell RNA sequencing (scRNA-seq) data from MIBC patient-derived organoids to characterize the molecular features of bladder cancer cells co-expressing IGF2BP3 and SPHK1. Spatial transcriptomics (ST) and co-detection by indexing (CODEX) analysis were used to describe the spatial distribution and interactions of IGF2BP3 + SPHK1 + bladder cancer cells and immune cells.ResultsA subset of CD274 + ALDH + CSC-like cells was identified, associating with immunosuppression and low survival rates in MIBC patients. IGF2BP3, an m6A reader gene, was found to be upregulated in the CD274 + ALDH + CSC-like cell population and linked to poor clinical prognosis in MIBC. Knockout of IGF2BP3 dramatically promoted cell apoptosis and reduced cell proliferation in T24 cells. By integrating MeRIP-seq and bulk RNA-seq analyses, we identified SPHK1 served as a substrate for IGF2BP3 in an m6A-dependent manner. Further snRNA-seq, scRNA-seq, ST, and CODEX analysis revealed a closer topographical distance between IGF2BP3 + SPHK1 + bladder cancer cells and exhausted CD8 + T cells, providing one explanation for the superior response to immunotherapy in IGF2BP3 + SPHK1 + bladder cancer cells-enriched patients. Finally, an ICI-associated signature was developed based on the enriched genes of IGF2BP3 + SPHK1 + bladder cancer cells, and its potential ability to predict the response to immunotherapy was validated in two independent immunotherapy cohort.ConclusionsOur study highlighted the critical involvement of the IGF2BP3/SPHK1 signaling in maintaining the stemness of CSCs and promoting MIBC progression. Additionally, these findings suggested that the IGF2BP3/SPHK1 signaling might serve as a biomarker for prognosis and immunotherapy response in MIBC.

Interference of FZD2 suppresses proliferation, vasculogenic mimicry and stemness in glioma cells via blocking the Notch/NF‑κB signaling pathway.

Frizzled family protein 2 (FZD2) is widely associated with tumor development and metastasis. The present study aimed to gain an insight into the role and regulatory mechanism of FZD2 in glioma. The expression level of FZD2 in normal astrocyte and glioma cells was determined by reverse transcription-quantitative PCR and western blotting, and cell transfection was conducted for FZD2 expression knockdown. Malignant behaviors including cell proliferation, migration and invasion, vasculogenic mimicry (VM) and cell stemness were determined using Cell Counting Kit-8, 5-Ethynyl-2'-deoxyuridine (EdU) staining, colony formation, wound healing, Transwell, 3D culturing and sphere formation assays. The expression levels of proteins related to stemness, epithelial-mesenchymal transition (EMT) and Notch/NF-κB signaling were measured by western blotting. Then, the Notch agonist, Jagged-1 (JAG), was adopted for rescue experiments. The results demonstrated that FZD2 was highly expressed in glioma cells. Interference of FZD2 expression suppressed the proliferation of glioma cells, as evidenced by the reduced cell viability and the number of EdU+ cells and colonies. Meanwhile, the reduced sphere formation ability and decreased protein expression of Nanog, Sox2 and Oct4 following FZD2 knockdown confirmed that FZD2 repressed cell stemness in glioma. Additionally, FZD2 knockdown suppressed the migration, invasion, EMT and VM formation capabilities of glioma cells, and also blocked the Notch/NF-κB signaling pathway. Furthermore, activation of Notch by JAG treatment partially reversed the aforementioned FZD2 knockdown-mediated changes in glioma cell malignant behaviors. In conclusion, FZD2 may contribute to glioma progression through activating the Notch/NF-κB signaling pathway, providing a plausible therapeutic target for the treatment of glioma.

Novel repurposing of sulfasalazine for the treatment of adrenocortical carcinomas, probably through the SLC7A11/xCT-hsa-miR-92a-3p-OIP5-AS1 network pathway

BackgroundRecent multigenomic analysis of adrenocortical carcinomas (ACCs) identified SLC7A11/xCT as a novel biomarker. The Food and Drug Administration–approved anti-inflammatory drug, sulfasalazine (SAS), induces ferroptosis by blocking SLC7A11 expression. We hypothesize that SAS could be repurposed to target ACC cells. MethodsExpression of SLC7A11 and its association with ACC survival was analyzed using Gene Expression Profiling Interactive Analysis (GEPIA). The validated ACC cell lines NCI-H295R, ACC1, and ACC2 were grown in 2D culture. In vitro studies included the CellTiter-Glo assay to calculate viability, Western blot (WB) analysis for apoptosis and other target protein changes, reverse transcriptase polymerase chain reaction for steroidogenic enzyme changes, C11BODIPY for lipid peroxidation, and mass spectrometry for changes in lipids. ResultsThe Cancer Genome Atlas Program database analysis in GEPIA showed that SLC7A11 and linked long noncoding RNA OAP5-AS1 are highly expressed in ACC tumors versus normal adrenals (n = 77 vs 128; P < .05). This was associated with poor overall and disease-free survival with hazard ratios of 4.3 and 5.2 for SLC7A11 and 4.8 and 2.7 for OAP5-AS1, respectively. ACC cell line half-inhibitory maximum concentration values after 72-hour SAS treatment ranged from 412 nM (ACC1) to 799 nM (ACC2), and all showed cleavage of poly (ADP-ribose) polymerase, upregulation of p-Akt and p-ERK, and downregulation of GPX4 and SLC7A11 (P < .05) by WB analysis. Sphere formation, migration, and invasion assay showed inhibition, and lipid peroxidation using C11BODIPY, increase in intracellular iron, induction of oxidative stress, and significant upregulation of oxidized polyunsaturated fatty acid phospholipids (P < .05 each) by mass spectrometry suggests induction of ferroptosis. ConclusionSAS downregulates tSLC7A11 in ACCs, targets the Akt/ERK pathway and lipid metabolism, and induces cell death in vitro, warranting additional translational studies to define its therapeutic potential in ACC.

N6-methyladenosine-modified TRIM37 augments sunitinib resistance by promoting the ubiquitin-degradation of SmARCC2 and activating the Wnt signaling pathway in renal cell carcinoma

Tripartite motif-containing 37 (TRIM37) is reportedly a key member of the superfamily of TRIM proteins. Emerging evidence underscores the close association between dysregulated TRIM37 expression and the progression of various human malignancies. However, the precise biological functions and regulatory mechanisms of TRIM37 remain elusive. This study aimed to elucidate the impact of TRIM37 on the chemotherapy sensitivity of renal cell carcinoma (RCC) and uncover its specific molecular regulatory role. Using RT-qPCR and western blot assays, we assessed TRIM37 expression in both RCC patients and RCC cells. Through in vitro and in vivo experiments, we investigated the effects of TRIM37 silencing and overexpression on RCC cell proliferation, stemness capacity, and chemotherapy sensitivity using colony formation and sphere formation assays. Additionally, a co-immunoprecipitation (Co-IP) experiment was conducted to explore putative interacting proteins. Our results revealed elevated TRIM37 expression in both RCC patient tumor tissues and RCC cells. Functional experiments consistently demonstrated that TRIM37 silencing reduced proliferation and stemness capacity while enhancing chemotherapy sensitivity in RCC cells. Furthermore, we discovered that TRIM37 mediates the degradation of SMARCC2 via ubiquitin-proteasome pathways, thereby further activating the Wnt signaling pathway. In conclusion, this study not only sheds light on the biological role of TRIM37 in RCC progression but also identifies a potential molecular target for therapeutic intervention in RCC patients.

Cephalomannine reduces radiotherapy resistance in non-small cell lung cancer cells by blocking the β-catenin-BMP2 signaling pathway

BackgroundThe management of non-small cell lung cancer (NSCLC) often includes the use of radiotherapy, with individual outcomes being impacted by the tumor's response to this treatment modality. Cephalomannine (CPM), a taxane diterpenoid found in Taxus spp, has been found to have anti-tumor activity. This study was aim to the explore the role and mechanism by which CPM affects radiotherapy resistance in NSCLC. MethodsH460 cells were pretreated with different doses of CPM. H460 cells were transfected with β-catenin overexpression plasmids. The cell viability, colony-forming ability, migration ability, and sphere-forming ability and apoptosis of the cells were measured by using CCK-8, colony-forming, transwell, and sphere-forming assay and flow cytometry. Western blot assay was employed to detect the expression of β-catenin and BMP2. ResultsThe cell viability, proliferation, migration and sphere-forming ability of cells in the radiotherapy-resistant (RR) group were significantly higher than those in the radiotherapy-sensitivity (RS) group. Conversely, the apoptosis rate of cells in the RR group was lower than that in the RS group. However, after CPM pretreatment of RR group cells, the above phenomena were reversed in a CPM dose-dependent manner. Subsequently, pretreatment with CPM resulted in a decrease in the expression levels of β-catenin and BMP2 in the RR group. In addition, overexpression of β-catenin mitigated the inhibitory effects of CPM on radiotherapy-resistant NSCLC cells. ConclusionCPM has the potential to decrease radiotherapy resistance in NSCLC cells by inhibiting the β-catenin-BMP2 signaling pathway, promoting apoptosis, and ultimately impeding cell growth.

USP1-mediated deubiquitination of KDM1A promotes the malignant progression of triple-negative breast cancer.

Previous research has indicated the highly expressed lysine-specific histone demethylase 1A (KDM1A) in several human malignancies, including triple-negative breast cancer (TNBC). However, its detailed mechanisms in TNBC development remain poorly understood. The mRNA levels of KDM1A and Yin Yang 1 (YY1) were determined by RT-qPCR analysis. Western blot was performed to measure KDM1A and ubiquitin-specific protease 1 (USP1) protein expression. Cell proliferation, apoptosis, invasion, migration and stemness were evaluated by MTT assay, EdU assay, flow cytometry, transwell invasion assay, wound-healing assay and sphere-formation assay, respectively. ChIP and dual-luciferase reporter assays were conducted to determine the relationship between YY1 and KDM1A. Xenograft tumor experiment and IHC were carried out to investigate the roles of USP1 and KDM1A in TNBC development in vivo. The highly expressed KDM1A was demonstrated in TNBC tissues and cells, and KDM1A knockdown significantly promoted cell apoptosis, and hampered cell proliferation, invasion, migration, and stemness in TNBC cells. USP1 could increase the stability of KDM1A via deubiquitination, and USP1 depletion restrained the progression of TNBC cells through decreasing KDM1A expression. Moreover, YY1 transcriptionally activated KDM1A expression by directly binding to its promoter in TNBC cells. Additionally, USP1 inhibition reduced KDM1A expression to suppress tumor growth in TNBC mice in vivo. In conclusion, YY1 upregulation increased KDM1A expression via transcriptional activation. USP1 stabilized KDM1A through deubiquitination to promote TNBC progression.

Effects of normal mitochondrial transplantation on proliferation, apoptosis and stemness of triple-negative breast cancer cells

Objectives: To observe the mitochondrial morphology of normal and triple-negative breast cancer cells, extract mitochondria from normal cells, and investigate the effects of mitochondrial transplantation on proliferation, apoptosis, and stemness of triple-negative breast cancer cells. Methods: The morphology of mitochondria was observed by transmission electron microscope. Mitochondria were extracted by mitochondrial extraction kit, mitochondrial protein was identified by western blot, and mitochondrial activity was detected by mitochondrial membrane potential detection kit. MitoTracker Green or MitoTracker Deep Red fluorescent probes were used to label the mitochondria of living cells, and the degree of mitochondria entering LTT cells was observed by confocal laser microscopy at 12, 24, and 96 hours. The effects of mitochondrial transplantation on proliferation, apoptosis, and stemness of breast cancer cells were examined by CCK8, colony formation assay, flow cytometry, and sphere formation assay after 24 hours of mitochondrial transplantation. Results: The mitochondria of normal cells were rod-shaped or elongated, while the mitochondria of triple-negative breast cancer cells were swollen and vacuolated. Western blot results showed that cytochrome c oxidase subunit I (MT-CO1) protein encoded by mitochondria was present in the isolated mitochondria. The content of heat shock protein 60 (HSP60) was higher in mitochondria than that in cytoplasm. The result of the multi-mode microplate reader showed that the content of mitochondrial J-aggregates/monomer was 1.67±0.06, which was significantly higher than 0.35±0.04 of the control group (P＜0.001). Exogenous mitochondria were observed in LTT cells at 12, 24, and 96 hours after mitochondrial transplantation. The results of the CCK8 experiment showed that OD450 of LTT cells was 0.27±0.13 after 48 hours transplantation, which was lower than 0.62±0.36 of the control group (P=0.023). The OD450 of MDA-MB-468 cells was 0.30±0.03, which was lower than 0.65±0.10 of the control group (P=0.004). After 120 hours of mitochondrial transplantation, OD450 in both groups was still significantly lower than that in the control group (P＜0.01). The number of clones formed by mitochondrial transplantation of LTT cells was 21.33±7.31, which was lower than 35.22±13.59 of the control group (P=0.016). Flow cytometry showed that the early apoptosis rate of LTT cells was (30.07±2.15)% after 24 hours of mitochondrial transplantation, which was higher than 2.07±1.58 of the control group (P＜0.001). The proportion of early apoptosis in MDA-MB-468 cells was 24.47%±5.22%, which was higher than (7.83±2.06)% in the control group (P=0.007). In addition, the number of mitochondria transplanted LTT cells into the cell sphere was 46.25±5.40, which was significantly lower than 62.58±6.43 of the control group (P＜0.001). Conclusion: Normal mitochondria can enter triple-negative breast cancer cells by co-culture, inhibit the proliferation and stemness of triple-negative breast cancer cells, and promote the apoptosis of triple-negative breast cancer cells.

Mechanism study of serum extracellular nano-vesicles miR-412-3p targeting regulation of TEAD1 in promoting malignant biological behavior of sub-centimeter lung nodules.

To investigate the impact and potential mechanisms of serum extracellular nano-vesicles (sEVs) miR-412-3p released from sub-centimeter lung nodules with a diameter of ⩽ 10mm on the malignant biological function of micro-nodular lung cancer (mnLC). A total of 87participants were included and divided into a mnLC group (n= 30), a benign lung nodule (BLN) group (n= 27), and a healthy people control group (n= 30). Transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and Western blot (WB) were used to measure the morphological characteristics and surface markers of sEVs. In vitro analysis, real-time quantitative polymerase chain reaction (RT-qPCR), CCK-8 cell proliferation assay, clone formation assay, Transwell, stem cell sphere-forming assay, and WB assay were conducted to verify the effect of miR-412-3p/TEAD1 signaling axis on the biological function of lung cancer cells through, respectively. Further validation was conducted using the serum sEVs of the participants. The expression level of sEVs-miR-412-3p in the mnLC group was significantly higher than that in the BLN and healthy groups (P< 0.01). In lung cancer cell lines, miR-412-3p can negatively regulate the targeted gene TEAD1. The miR-412-3p/TEAD1 signaling axis is involved in promoting the EMT signaling pathway and regulating the malignant biological functions of lung cancer cell proliferation, migration, and stemness (P< 0.05). In addition, sEVs in the mnLC group significantly promoted lung cancer cell proliferation, migration, and stemness compared to the BLN and healthy groups, inhibited the expression of E-cadherin and TEAD1 in lung cancer cells, and promoted the expression of N-cadherin and Vimentin (P< 0.05). sEVs-miR-412-3p could promote the biological process of EMT, and lead to the occurrence of malignant biological behavior in sub-centimeter lung nodules. This provides evidence for the miR-412-3p/TEAD1 signaling axis as a potential therapeutic target for mnLC.

Abstract A077: The role of RhoV in basal-like pancreatic cancer

Abstract Background Pancreatic ductal adenocarcinoma is a devastating disease lacking targeted therapy. Basal-like pancreatic cancer is a tumor subtype with a worse clinical outcome than other subtypes. These cancers are characterized by the expression of basal keratins and mesenchymal markers. However, the genes that drive the basal-like phenotype are poorly understood. Ras homolog family member V (RhoV) is one of the Rho GTPases, and it has been demonstrated to drive the progression of lung and breast cancers. The current study aims to reveal the role of RhoV in basal-like pancreatic cancer. Design RhoV, p63, and CK5/6 were stained in sequential sections by immunohistochemistry. Expression of RhoV in pancreatic cancer and cell lines was reanalyzed based on the data from ProteinAtlas and Broad Insitute DepMap Portal. Basal cell line, BxPC3, and non-basal cell line, Panc1 were selected for functional evaluation based on their differentiated RhoV expression. RhoV gene was overexpressed and knocked down using the CRISPR/gRNA-based Lentiviral system, followed by sphere formation, colony formation, migration, and invasion assays. Results RhoV, p63, and CK5/6 were expressed in the same histologic location of basal pancreatic cancer. The gene expression level of RhoV was co-expressed with p63 (a classic basal marker) in four pancreatic cancer cell lines (broadinstitute.org). Knockout of RhoV by three runs of gRNAs in BxPC3 cells all significantly attenuated tumor sphere formation with less colony formation as compared to mock knockout. Overexpression of RhoV in non-basal-like cells, Panc 1, significantly increased the size of sphere formation, numbers of colony formation, and p38 activation compared to EV control. Cell migration and invasion assays showed the same RhoV-dependent migration and invasion in corresponding cells. Panc1 cells with RhoV knockout significantly generated smaller tumor xenografts in immunodeficient mice and RhoV overexpression led to larger tumor sizes. Conclusion Finding the driver of the basal-like phenotype helps to reveal the pathophysiology of the basal-like subtype of pancreatic cancer and facilitates the identification of new targets for therapeutic purposes. Our preliminary results indicated that RhoV, a small G protein from the Rho family of GTPases, played essential roles in tumor proliferation and progression, by activating the p38 signaling pathway. Further study will be focused on revealing Rhov's downstream pathways and exploring the role of RhoV in apoptosis/cell cycle, cell metabolism, autophagy, etc. in basel-like pancreatic cancer. Citation Format: Shang Wu, Jia Feng, Selina Gao, Ting Wang, Zebang Li, Yifei Liu, Chiung-Kuei Huang, Shaolei Lu. The role of RhoV in basal-like pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A077.