CD44 Knockdown Research Articles

Abstract 4128189: CD44 Knockdown Attenuates the Abnormal Cellular Phenotype of BMPR2-Deficient Primary Human Pulmonary Artery Endothelial Cells

Background: BMPR2 gene silencing in primary human pulmonary artery endothelial cells (PAECs) produces a proliferative, hypermigratory PAH-like cellular phenotype. Genome-wide expression profiling in BMPR2 -silenced cells uncovered CD44 , a cancer stem cell marker associated with tumor progression and metastasis, among the top upregulated transcripts. Therapeutic strategies that block CD44 or reduce its expression are currently in various stages of development for cancer. Thus, mechanistic studies investigating the contribution of CD44 to vascular remodeling in PAH may reveal new therapeutic targets. Hypothesis: Upregulation of CD44 contributes to the abnormal phenotype of BMPR2-deficient PAECs and thus may contribute to vascular remodeling in PAH. Aims: Determine the effect of CD44 -silencing on gene expression and cell proliferation in BMPR2-deficient PAECs. Methods: Commercially available primary, human PAECs were transfected with scrambled control (siCTRL) or gene specific siRNA(s). PAH patient-derived (N=24) and failed donor-derived (N=11) PAECs were obtained from the PHBI. mRNA and protein expression were determined by quantitative RT-PCR and Western blotting, respectively. Cell proliferation was assessed by BrdU incorporation 96h after siRNA transfection. Data was analyzed using t-tests or ANOVA with post hoc pairwise comparisons. Results: Consistent with our previous findings, CD44 protein expression was increased 4-fold in BMPR2 -silenced PAECs 48h following siRNA transfection (P<0.0001 vs siCTRL; N=10 unique donors). Genes involved in endothelial-mesenchymal transition and cell proliferation were also increased in BMPR2 -silenced PAECs including HMGA1 , ID1 , SNAI1, and SNAI2 (P<0.01 for all vs siCTRL; N=5 independent experiments) and co-silencing CD44 attenuated their upregulation (P<0.05 for all vs siBMPR2 alone). Importantly, CD44 knockdown reduced PAEC proliferation in the absence (P=0.01 vs siCTRL) and presence of BMPR2 deficiency (P=0.002 vs siBMPR2 alone). Like BMPR2 -silenced PAECs, CD44 mRNA levels were higher in PAH patient-derived versus failed donor control PAECs (P=0.07). Conclusions: CD44 knockdown corrected aberrant gene expression associated with endothelial-mesenchymal transition and reduced cellular proliferation in BMPR2-deficient PAECs. Thus, endothelial CD44 upregulation may contribute to pathologic vascular remodeling in PAH and represents an unexplored therapeutic target.

Bioinformatics investigation of the prognostic value and mechanistic role of CD9 in glioma

In recent years, CD9 has been extensively studied as a potential biomarker for cancer. However, the biological role of CD9 in gliomas remains unclear. This study investigates the function of CD9 in gliomas and its molecular mechanisms. Utilizing pan-cancer analysis with TCGA, CGGA, and GEO databases, differential expression of CD9 was observed in 11 tumor types within the TCGA cohort, and it was associated with patient survival rates. Analysis of the CGGA glioma database revealed that patients with high CD9 expression had lower survival rates. The area under the ROC curve (AUC) for GSE16011 was greater than 0.7, indicating a high discriminative ability. Through gene set enrichment analysis (GSEA), immune-related analysis, and CD9 mutation detection, CD9 was found to have the strongest correlation with neutrophil involvement (cor = 0.30, P < 0.05), and the high CD9 expression group exhibited higher rejection responses and TIDE scores, suggesting a lower likelihood of successful immunotherapy. The high CD9 expression group was more sensitive to 81 drugs, indicating potential therapeutic effects for gliomas. Furthermore, overexpression of CD9 in gliomas may be associated with gene mutations. Down-regulation or up-regulation of CD9 expression in the glioblastoma cell line LN229 showed that CD9 could positively regulate the migratory ability of LN229 cells. Further, several marker genes, such as VEGFR-2, TGF-β1, CASP1 and PI3K, were down regulated in CD9 knockdown cell lines and up regulated in CD9 overexpression cell lines, compared with control cell line. This study preliminarily explores the role of CD9 in gliomas and its prognostic value, providing new insights for personalized treatment strategies in glioma therapy.

Combined knockdown of CD151 and MMP9 may inhibit the malignant biological behaviours of triple-negative breast cancer through the GSK-3β/β-catenin-related pathway

Triple-negative breast cancer (TNBC) represents a significant health concern for women worldwide, and the overproduction of MMP9 and CD151 is associated with various cancers, influencing tumour growth and progression. This study aimed to investigate how CD151 and MMP9 affect TNBC cell migration, apoptosis, proliferation, and invasion. Immunohistochemical experiments revealed that CD151 and MMP9 were positively expressed in triple-negative breast cancer, and lymph node metastasis, the histological grade, and CD151 and MMP9 expression were found to be independent prognostic factors for the survival of patients with triple-negative breast cancer. Cytological experiments indicated that the knockdown of CD151 or MMP9 slowed triple-negative breast cancer cell growth, migration, and invasion and increased the apoptosis rate. Compared with CD151 knockdown, double MMP9 and CD151 knockdown further promoted cell death and inhibited TNBC cell proliferation, migration, and invasion. Moreover, β-catenin and p-GSK-3β were significantly downregulated. In summary, simultaneously silencing CD151 and MMP9 further suppressed the proliferation, migration and invasion of TNBC cells and promoted their apoptosis. One possible strategy for inducing this effect is to block the GSK-3β/β-catenin pathway.

CD24 affects the immunosuppressive effect of tumor-infiltrating cells and tumor resistance in a variety of cancers

BackgroundCluster of differentiation 24 (CD24) is a highly glycosylated glycosylphosphatidylinositol (GPI)-anchored surface protein, expressed in various tumor cells, as a "don't eat me" signaling molecule in tumor immune. This study aimed to investigate the potential features of CD24 in pan-cancer.MethodsThe correlations between 22 immune cells and CD24 expression were using TIMER analysis. R package “ESTIMATE” was used to predict the proportion of immune and stromal cells in pan-cancer. Spearman's correlation analysis was performed to evaluate the relationships between CD24 expression and immune checkpoints, chemokines, mismatch repair, tumor mutation burden and microsatellite instability, and qPCR and western blot were conducted to assess CD24 expression levels in liver hepatocellular carcinoma (LIHC). In addition, loss of function was performed for the biological evaluation of CD24 in LIHC.ResultsCD24 expression was positively correlated with myeloid cells, including neutrophils and myeloid-derived suppressor cells, in various tumors, such as BLCA, HNSC-HPV, HNSC, KICH, KIRC, KIRP, TGCT, THCA, THYM, and UCEC. In contrast, anti-tumor NK cells and NKT cells showed a negative association with CD24 expression in BRCA-Her2, ESCA, HNSC-HPV, KIRC, THCA, and THYM. The top three tumors with the highest correlation between CD24 and ImmuneScore were TGCT, THCA, and SKCM. Functional enrichment analysis revealed CD24 expression was negatively associated with various immune-related pathways. Immune checkpoints and chemokines also exhibited inverse correlations with CD24 in CESC, CHOL, COAD, ESCA, READ, TGCT, and THCA. Additionally, CD24 was overexpressed in most tumors, with high CD24 expression in BRCA, LIHC, and CESC correlating with poor prognosis. The TIDE database indicated tumors with high CD24 expression, particularly melanoma, were less responsive to PD1/PD-L1 immunotherapy. Finally, CD24 knockdown resulted in impaired proliferation and cell cycle progression in LIHC.ConclusionCD24 participates in regulation of immune infiltration, influences patient prognosis and serves as a potential tumor marker.

Lipid Regulatory Element Interact with CD44 on Mitochondrial Bioenergetics in Bovine Adipocyte Differentiation and Lipometabolism.

The CD44 gene is a critical factor in animal physiological processes and has been shown to affect insulin resistance and fat accumulation in mammals. Nevertheless, little research has been conducted on its precise functions in lipid metabolism and adipogenic differentiation in beef cattle. This study analyzed the expression of CD44 and miR-199a-3p during bovine preadipocyte differentiation. The luciferase reporter assay demonstrated that CD44 was a direct target of miR-199a-3p. Increased accumulation of lipid droplets and triglyceride levels, altered fatty acid metabolism, and accelerated preadipocyte differentiation were all caused by the upregulation of miR-199a-3p or a reduction in CD44 expression. CD44 knockdown upregulated the expression of adipocyte-specific genes (LPL and FABP4) and altered the levels of lipid metabolites (SOPC, l-arginine, and heptadecanoic acid). Multiomics highlights enriched pathways involved in energy metabolism (MAPK, cAMP, and calcium signaling) and shifts in mitochondrial respiration and glycolysis, indicating that CD44 plays a regulatory role in lipid metabolism. The findings show that intracellular lipolysis, glycolysis, mitochondrial respiration, fat deposition, and lipid droplet composition are all impacted by miR-199a-3p, which modulates CD44 in bovine adipocytes.

Progesterone Receptor Signaling Promotes Cancer Associated Fibroblast Mediated Tumorigenicity in ER+ Breast Cancer.

Breast cancer progression involves intricate interactions between cancer cells and the tumor microenvironment (TME). This study elucidates the critical role of progesterone receptor (PR) signaling in mediating the protumorigenic effects of cancer-associated fibroblasts (CAFs) on estrogen receptor-positive (ER+) luminal breast cancer cells. We demonstrate that CAFs produce physiologically relevant levels of estrogen and progesterone, which significantly contribute to breast cancer tumorigenicity. Specifically, CAF conditioned media (CM) promoted PR-dependent anchorage-independent growth, tumorsphere formation/stem cell expansion, and CD44 upregulation. CAF cells formed co-clusters more frequently with PR+ breast cancer cells relative to PR-null models. While both PR isoforms mediated these actions, PR-A was a dominant driver of tumorsphere formation/stemness, while PR-B induced robust CD44 expression and CAF/tumor cell co-cluster formation. CD44 knockdown impaired CAF/tumor cell co-clustering. Fibroblast growth factor 2 (FGF2), also secreted by CAFs, phosphorylated PR (Ser294) in a MAPK-dependent manner and activated PR to enhance CD44 expression and breast cancer tumorigenicity. The FGF receptor (FGFR) inhibitor PD173074 diminished CAF- and FGF2-dependent PR activation, tumorsphere formation, and co-clustering. In summary, this study reveals a novel mechanism through which stromal CAFs orchestrate elevated PR signaling in ER+ luminal breast cancer via secretion of both progesterone and FGF2, a potent activator of ERK1/2. Understanding tumor cell/TME interactions provides insights into potential therapeutic strategies aimed at disrupting PR- and/or FGF2/FGFR-dependent signaling pathways to prevent early metastasis in patients with ER+ breast cancer.

RBM10 loss induces aberrant splicing of cytoskeletal and extracellular matrix mRNAs and promotes metastatic fitness.

RBM10 modulates transcriptome-wide cassette exon splicing. Loss-of-function RBM10 mutations are enriched in thyroid cancers with distant metastases. Analysis of transcriptomes and genes mis-spliced by RBM10 loss showed pro-migratory and RHO/RAC signaling signatures. RBM10 loss increases cell velocity. Cytoskeletal and ECM transcripts subject to exon-inclusion events included vinculin (VCL), tenascin C (TNC) and CD44. Knockdown of the VCL exon inclusion transcript in RBM10-null cells reduced cell velocity, whereas knockdown of TNC and CD44 exon-inclusion isoforms reduced invasiveness. RAC1-GTP levels were increased in RBM10-null cells. Mouse Hras G12V /Rbm1O KO thyrocytes develop metastases that are reversed by RBM10 or by combined knockdown of VCL, CD44 and TNC inclusion isoforms. Thus, RBM10 loss generates exon inclusions in transcripts regulating ECM-cytoskeletal interactions, leading to RAC1 activation and metastatic competency. Moreover, a CRISPR-Cas9 screen for synthetic lethality with RBM10 loss identified NFkB effectors as central to viability, providing a therapeutic target for these lethal thyroid cancers.

LINC00525 enhances ZNF460-regulated CD24 expression through the sponge miR-125a-5p to promote malignant progression of breast cancer

IntroductionCD24 is a highly glycosylated glycosylphosphatidylinositol anchored membrane protein that plays an important role in tumor progression. The aim of this study was to investigate the effect of abnormal expression of CD24 on the proliferation, migration and invasion of breast cancer (BC) cells, and the molecular mechanism of regulating CD24 expression in breast cancer.MethodologyThe bioinformatics method was used to predict the expression level of CD24 in BC and its relationship with the occurrence and development of BC. IHC, RT-qPCR and WB were used to detect the expression of CD24 in BC tissues and cells. The proliferation of CD24 was evaluated by CCK-8 and colony formation assay, and the migration and invasion of CD24 were evaluated by wound healing and transwell. In addition, the effect of CD24 on the malignancy of BC in vivo was further evaluated by subcutaneous tumorigenesis assay. Molecular mechanisms were measured by luciferase reporter assays, biotin-labeled miRNA pull-down assay, RIP, and western blotting.ResultsThe results show that CD24 is highly expressed in breast cancer tissues and cell lines, and knockdown of CD24 in vivo and in vitro can inhibit the proliferation, migration and invasion of BC cells. Mechanistically, the transcription factor ZNF460 promotes its expression by binding to the CD24 promoter, and the expression of ZNF460 is regulated by miR-125a-5p, which inhibits its expression by targeting the 3’UTR of ZNF460. In addition, LINC00525 acts as a ceRNA sponge to adsorb miR-125a-5p and regulate its expression.ConclusionsOverexpression of CD24 is involved in the development and poor prognosis of BC, which can be used as a potential target for the treatment of BC and provide a theoretical basis for the treatment of BC.

Abstract PO1-24-02: Enhancement of TGF-β Receptor Inhibitor Efficacy through CD44 Suppression in Claudin-low Breast Cancer

Abstract Introduction: Claudin-low breast cancer is mostly classified as triple-negative breast cancer and is known to possess cancer stem cell properties with high expression of epithelial-to-mesenchymal transition (EMT) markers. However, specific therapeutic targets for this subtype have not yet been identified. While reports suggest that inhibition of EMT using EMT inhibitors can suppress cell and tumor proliferation, monotherapy may not be sufficient. The expression of CD44, a surface marker of cancer stem cells, has been reported to be involved in multiple signaling pathways, promoting cancer growth and invasion. In this study, we focus on CD44 and the TGF-β receptor, which is involved in EMT, to investigate the effect of inhibiting TGF-β receptor through CD44 inhibition in Claudin-low breast cancer and validate its potential as an effective treatment. Methods: SUM159 and MDA-MB-231 cell lines were used as Claudin-low breast cancer cell models. CD44 knockdown cells were established to examine the effects of TGF-β receptor inhibition and downstream signaling. Results: CD44 knockdown did not affect the expression of TGF-β receptor. Both SUM159 and MDA-MB-231 cells showed comparable cell growth inhibition through CD44 knockdown and TGF-β receptor inhibition, with enhanced effects observed in CD44 knockdown cells in response to TGF-β receptor inhibition. Furthermore, CD44 knockdown combined with TGF-β receptor inhibition significantly reduced the expression of Smad2/3. Conclusion: In Claudin-low breast cancer cells, CD44 knockdown enhances the effectiveness of TGF-β receptor inhibition and significantly influences the expression level of Smad2/3. Citation Format: Ryoichi Matsunuma, Sae Imada, Shoko Sato, Ryosuke Hayami, Michiko Tsuneizumi. Enhancement of TGF-β Receptor Inhibitor Efficacy through CD44 Suppression in Claudin-low Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-24-02.

POLE2 promotes osteosarcoma progression by enhancing the stability of CD44.

Osteosarcoma (OS) is the most prevalent primary malignancy of bone in children and adolescents. It is extremely urgent to develop a new therapy for OS. In this study, the GSE14359 chip from the GEO database was used to screen differentially expressed genes in OS. DNA polymerase epsilon 2 (POLE2) was confirmed to overexpress in OS tissues and cell lines by immunohistochemical staining, qPCR and Western blot. Knockdown of POLE2 inhibited the proliferation and migration of OS cells in vitro, as well as the growth of tumors in vivo, while the apoptosis rate was increased. Bioinformatics analysis revealed that CD44 and Rac signaling pathway were the downstream molecule and pathway of POLE2, which were inhibited by knockdown of POLE2. POLE2 reduced the ubiquitination degradation of CD44 by acting on MDM2. Moreover, knockdown of CD44 inhibited the tumor-promoting effects of POLE2 overexpression on OS cells. In conclusion, POLE2 augmented the expression of CD44 via inhibiting MDM2-mediated ubiquitination, and then activated Rac signaling pathway to influence the progression of OS, indicating that POLE2/CD44 might be potential targets for OS treatment.

Pan-cancer and single-cell analyses identify CD44 as an immunotherapy response predictor and regulating macrophage polarization and tumor progression in colorectal cancer.

Cluster of differentiation (CD) 44 is a non-kinase cell surface transmembrane glycoprotein critical for tumor maintenance and progression. We conducted a systematic analysis of the expression profile and genomic alteration profile of CD44 in 33 types of cancer. The immune characteristics of CD44 were comprehensively explored by TIMER2.0 and CIBERSORT. In addition, the CD44 transcriptional landscape was examined at the single-cell level. Then, Pseudotime trajectory analysis of CD44 gene expression was performed using Monocle 2, and CellChat was utilized to compare the crosstalk differences between CD44+monocytes and CD44- monocytes. Tumor immune dysfunction and exclusion (TIDE) was used to evaluate the predictive ability of CD44 for immune checkpoint blockade (ICB) responses. The effects of CD44 on colorectal cancer (CRC) and macrophage polarization were investigated by knocking down the expression of CD44 in HCT-116 cell and macrophages in vitro. The expression of CD44 elevated in most cancers, predicting unfavorable prognosis. In addditon, CD44 was correlation with immune cell infiltration and key immune regulators. CD44+ monocytes had a higher information flow intensity than CD44- monocytes. CD44 had good predictive ability for immune checkpoint blockade responses. Knockdown of CD44 inhibited the proliferation, migration, and invasion of HCT-116 cell in vitro. Knockdown of CD44 inhibited M2 macrophage polarization. These findings suggest that CD44 is involved in regulating tumor development, macrophage polarization, and has certain predictive value for patient clinical prognosis and response to immunotherapy.

Abstract 4318: CD24 enhances cisplatin resistance in ovarian cancer by suppressing autophagy

Abstract Ovarian cancer is one of the most common gynecological cancers with the highest mortality rate. Most patients are diagnosed with advanced disease and will relapse due to chemoresistance. CD24, a highly glycosylated GPI-anchored membrane protein. Recent studies have shown that CD24 expression is significantly up-regulated in ovarian cancer and is associated with chemotherapy resistance, and CD24 also plays an inhibitory role in tumor immunity by binding to Siglec-10 on macrophages. However, the molecular mechanisms of how CD24 affects chemotherapy resistance in ovarian cancer remain unclear. In this study, we used shRNAs to knockdown CD24 and explore the impact and mechanism of CD24 on the chemotherapy resistance of ovarian cancer cells. The results showed that knockdown of CD24 in ovarian cancer cells SKOV3 and TOV21G significantly reduced cell proliferation and arrested the cell cycle in S phase. Knockdown of CD24 also significantly increased the sensitivity of ovarian cancer cells to cisplatin but had no effect on paclitaxol treatment. Further experiments showed that knockdown of CD24 increased cisplatin sensitivity by promoting autophagy-induced cell death. In addition, Gene Set Enrichment Analysis (GSEA) was used to analyze the correlation between the expression of CD24 and its biological functions in the TCGA ovarian cancer dataset. The results showed that CD24 is mostly correlated to cell proliferation and autophagy-related pathways in ovarian cancers. Further mouse xenograft tumor transplantation experiments also confirmed that knockdown of CD24 reduced tumor size and increased sensitivity to cisplatin treatment by increasing cell autophagy. Taken together, these results indicate that CD24 regulates cell growth and chemoresistance in ovarian cancer cells and that inhibition of CD24 may be helpful in the treatment of ovarian cancer. Citation Format: Yuh-Ling Chen, Tse-Ming Hong, Yu-Yi Wen. CD24 enhances cisplatin resistance in ovarian cancer by suppressing autophagy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4318.

Unraveling the role of CD24 in Hepatocellular carcinoma: Involvement of inactivated Hippo signaling and SOX4-mediated regulation

Hepatocellular carcinoma (HCC) is a prevalent type of liver cancer, and CD24 gene is reportedly involved in HCC progression. However, the precise regulatory mechanisms of CD24 in HCC remain unclear. In this study, we established a primary HCC mouse model and observed that CD24, induced by inactivation of the Hippo pathway, was highly expressed in HCC. Using a systematic molecular and genomic approach, we identified the Hippo-YAP1-SOX4 pathway as the mechanism through which YAP1 induces CD24 upregulation in HCC cells. CD24 knockdown significantly attenuated YAP1 activation-induced HCC. These findings shed light on the link between CD24 and HCC progression, particularly in the Hippo-inactivated subclass of HCC. Therefore, CD24 may serve as a potential target for specific treatment of this HCC subclass.

CD24 negativity reprograms mitochondrial metabolism to PPARα and NF-κB-driven fatty acid β-oxidation in triple-negative breast cancer

CD24 is a well-characterized breast cancer (BC) stem cell (BCSC) marker. Primary breast tumor cells having CD24-negativity together with CD44-positivity is known to maintain high metastatic potential. However, the functional role of CD24 gene in triple-negative BC (TNBC), an aggressive subtype of BC, is not well understood. While the significance of CD24 in regulating immune pathways is well recognized in previous studies, the significance of CD24 low expression in onco-signaling and metabolic rewiring is largely unknown. Using CD24 knock-down and over-expression TNBC models, our in vitro and in vivo analysis suggest that CD24 is a tumor suppressor in metastatic TNBC. Comprehensive in silico gene expression analysis of breast tumors followed by lipidomic and metabolomic analyses of CD24-modulated cells revealed that CD24 negativity induces mitochondrial oxidative phosphorylation and reprograms TNBC metabolism toward the fatty acid beta-oxidation (FAO) pathway. CD24 silencing activates PPARα-mediated regulation of FAO in TNBC cells. Further analysis using reverse-phase protein array and its validation using CD24-modulated TNBC cells and xenograft models nominated CD24-NF-κB-CPT1A signaling pathway as the central regulatory mechanism of CD24-mediated FAO activity. Overall, our study proposes a novel role of CD24 in metabolic reprogramming that can open new avenues for the treatment strategies for patients with metastatic TNBC.

High CD133 expression in proximal tubular cells in diabetic kidney disease: good or bad?

BackgroundProximal tubular cells (PTCs) play a critical role in the progression of diabetic kidney disease (DKD). As one of important progenitor markers, CD133 was reported to indicate the regeneration of dedifferentiated PTCs in acute kidney disease. However, its role in chronic DKD is unclear. Therefore, we aimed to investigate the expression patterns and elucidate its functional significance of CD133 in DKD.MethodsData mining was employed to illustrate the expression and molecular function of CD133 in PTCs in human DKD. Subsequently, rat models representing various stages of DKD progression were established. The expression of CD133 was confirmed in DKD rats, as well as in human PTCs (HK-2 cells) and rat PTCs (NRK-52E cells) exposed to high glucose. The immunofluorescence and flow cytometry techniques were utilized to determine the expression patterns of CD133, utilizing proliferative and injury indicators. After overexpression or knockdown of CD133 in HK-2 cells, the cell proliferation and apoptosis were detected by EdU assay, real-time cell analysis and flow analysis. Additionally, the evaluation of epithelial, progenitor cell, and apoptotic indices was performed through western blot and quantitative RT-PCR analyses.ResultsThe expression of CD133 was notably elevated in both human and rat PTCs in DKD, and this expression increased as DKD progressed. CD133 was found to be co-expressed with CD24, KIM-1, SOX9, and PCNA, suggesting that CD133+ cells were damaged and associated with proliferation. In terms of functionality, the knockdown of CD133 resulted in a significant reduction in proliferation and an increase in apoptosis in HK-2 cells compared to the high glucose stimulus group. Conversely, the overexpression of CD133 significantly mitigated high glucose-induced cell apoptosis, but had no impact on cellular proliferation. Furthermore, the Nephroseq database provided additional evidence to support the correlation between CD133 expression and the progression of DKD. Analysis of single-cell RNA-sequencing data revealed that CD133+ PTCs potentially play a role in the advancement of DKD through multiple mechanisms, including heat damage, cell microtubule stabilization, cell growth inhibition and tumor necrosis factor-mediated signaling pathway.ConclusionOur study demonstrates that the upregulation of CD133 is linked to cellular proliferation and protects PTC from apoptosis in DKD and high glucose induced PTC injury. We propose that heightened CD133 expression may facilitate cellular self-protective responses during the initial stages of high glucose exposure. However, its sustained increase is associated with the pathological progression of DKD. In conclusion, CD133 exhibits dual roles in the advancement of DKD, necessitating further investigation.

CD24 induced cellular quiescence-like state and chemoresistance in ovarian cancer cells via miR-130a/301a-dependent CDK19 downregulation

Cancer stem-like cell (CSC) is thought to be responsible for ovarian cancer recurrence. CD24 serves as a CSC marker for ovarian cancer and regulates the expression of miRNAs, which are regulators of CSC phenotypes. Therefore, CD24-regulated miRNAs may play roles in manifesting the CSC phenotypes in ovarian cancer cells. Our miRNA transcriptome analysis showed that 94 miRNAs were up or down-regulated in a CD24-high clone from an ovarian cancer patient compared to a CD24-low one. The CD24-dependent expression trend of the top 7 upregulated miRNAs (miR-199a-3p, 34c, 199a-5p, 130a, 301a, 214, 34b*) was confirmed in other 8 clones (4 clones for each group). CD24 overexpression upregulated the expression of miR-199a-3p, 34c, 199a-5p, 130a, 301a, 214, and 34b* in TOV112D (CD24-low) cells compared to the control, while CD24 knockdown downregulated the expression of miR-199a-3p, 199a-5p, 130a, 301a, and 34b* in OV90 (CD24-high) cells. miR-130a and 301a targeted CDK19, which induced a cellular quiescence-like state (increased G0/G1 phase cell population, decreased cell proliferation, decreased colony formation, and decreased RNA synthesis) and resistance to platinum-based chemotherapeutic agents. CD24 regulated the expression of miR-130a and 301a via STAT4 and YY1 phosphorylation mediated by Src and FAK. miR-130a and 301a were positively correlated in expression with CD24 in ovarian cancer patient tissues and negatively correlated with CDK19. Our results showed that CD24 expression may induce a cellular quiescence-like state and resistance to platinum-based chemotherapeutic agents in ovarian cancer via miR-130a and 301a upregulation. CD24-miR-130a/301a-CDK19 signaling axis could be a prognostic marker for or a potential therapeutic target against ovarian cancer recurrence.

Integrating spatial and single-cell transcriptomics to characterize the molecular and cellular architecture of the ischemic mouse brain.

Neuroinflammation is acknowledged as a pivotal pathological event after cerebral ischemia. However, there is limited knowledge of the molecular and spatial characteristics of nonneuronal cells, as well as of the interactions between cell types in the ischemic brain. Here, we used spatial transcriptomics to study the ischemic hemisphere in mice after stroke and sequenced the transcriptomes of 19,777 spots, allowing us to both visualize the transcriptional landscape within the tissue and identify gene expression profiles linked to specific histologic entities. Cell types identified by single-cell RNA sequencing confirmed and enriched the spatial annotation of ischemia-associated gene expression in the peri-infarct area of the ischemic hemisphere. Analysis of ligand-receptor interactions in cell communication revealed galectin-9 to cell-surface glycoprotein CD44 (LGALS9-CD44) as a critical signaling pathway after ischemic injury and identified microglia and macrophages as the main source of galectins after stroke. Extracellular vesicle-mediated Lgals9 delivery improved the long-term functional recovery in photothrombotic stroke mice. Knockdown of Cd44 partially reversed these therapeutic effects, inhibiting oligodendrocyte differentiation and remyelination. In summary, our study provides a detailed molecular and cellular characterization of the peri-infact area in a murine stroke model and revealed Lgals9 as potential treatment target that warrants further investigation.

CD44s and CD44v8-10 isoforms confer acquired resistance to osimertinib by activating the ErbB3/STAT3 signaling pathway

AimsAlthough epidermal growth factor receptor (EGFR)-mutant lung cancers respond well to osimertinib, acquired resistance to osimertinib eventually develops through EGFR-dependent and EGFR-independent resistance mechanisms. CD44 splicing variants are widely expressed in lung cancer tissues. However, it remains unclear whether specific splicing variants are involved in acquired resistance to osimertinib. Main methodsThe real-time PCR was performed to measure the expression levels of total CD44 and specific CD44 splicing variants (CD44s or CD44v). Gene knockdown and restoration were performed to investigate the effects of CD44 splicing variants on osimertinib sensitivity. Activation of the signaling pathway was evaluated using receptor-tyrosine-kinase phosphorylation membrane arrays, co-immunoprecipitation, and western blotting. Key findingsClinical analysis demonstrated that the expression level of total CD44 increased in primary cancer cells from lung adenocarcinomas patients after the development of acquired resistance to osimertinib. Furthermore, osimertinib-resistant cells showed elevated levels of either the CD44s variant or CD44v variants. Manipulations of CD44s or CD44v8-10 were performed to investigate their effects on treatment sensitivity to osimertinib. Knockdown of CD44 increased osimertinib-induced cell death in osimertinib-resistant cells. However, restoration of CD44s or CD44v8-10 in CD44-knockdown H1975/AZD-sgCD44 cells induced osimertinib resistance. Mechanically, we showed that ErbB3 interacted with CD44 and was transactivated by CD44, that consequently triggered activation of the ErbB3/STAT3 signaling pathway and led to CD44s- or CD44v8-10-mediated osimertinib resistance. SignificanceCD44 is a co-receptor for ErbB3 and triggers activation of the ErbB3 signaling axis, leading to acquired resistance to osimertinib. CD44/ErbB3 signaling may represent a therapeutic target for overcoming osimertinib resistance.

10027-CBMS-3 POSTOPERATIVE EPILEPTOGENICITY IN GLIOBLASTOMA ARE ACHIEVED AS THE RESULT OF INTERACTIVE FLUCTUATIONS OF GLUTAMATE AND STEM CELL MARKER

Abstract BACKGROUND AND OBJECTIVE In our recent Glioblastoma multiforme (GBM) cases, postoperative epilepsy mostly occurred later than twenty-eight days after surgery. CD44, a stem cell marker, is known to relate with tumor cell invasiveness, however, little are known with epilepsy nor glutamate (Glu). We investigated the relationship between CD44 and the pathophysiology of this post operative late-phase epilepsy. MATERIALS AND METHODS A total of 10 GBM cases received surgery and postoperative treatment at our institute were divided into two groups; 4 cases of epilepsy onset, group E, and 6 cases without, group NE. In each group, the tumor was separated into core and periphery, from which Glu was measured (Amino Acid Analyzer L8900; Hitachi High-Tech Corporation) with expression of xCT, EAAT2 and CD44 examined (Western blot). The same objects were also examined on our three glioma stem-like cell (GSC) lines. In addition, we figured Factor X (F-X) as a key related factor, and evaluated the same objects on the GSCs under conditioned F-X (under submission). RESULTS Group E showed higher Glu than group NE both in the core and periphery. CD44 expression was significantly higher in group E in the periphery, and xCT was higher in group E both in the core and periphery. EAAT2 was lower in group E both in the core and periphery. Among the GSCs, GSC-2 had the highest CD44 expression while having the lowest xCT and extracellular Glu, and the highest EAAT2. In addition, CD44 knockdown in GSC-2 resulted in significant increase of xCT expression and extracellular Glu. Furthermore, changing the concentration of F-X low to high led to decreased expression of CD44 and increased xCT. CONCLUSION The postoperative epileptogenicity could be gained by the increase of Glu which results from the alterations of CD44, xCT and EAAT2. F-X could enhance the ability of Glu discharge.

Hyaluronic Acid Induction Promotes the Differentiation of Human Neural Crest-like Cells into Periodontal Ligament Stem-like Cells.

Periodontal ligament (PDL) stem-like cells (PDLSCs) are promising for regeneration of the periodontium because they demonstrate multipotency, high proliferative capacity, and the potential to regenerate bone, cementum, and PDL tissue. However, the transplantation of autologous PDLSCs is restricted by limited availability. Since PDLSCs are derived from neural crest cells (NCs) and NCs persist in adult PDL tissue, we devised to promote the regeneration of the periodontium by activating NCs to differentiate into PDLSCs. SK-N-SH cells, a neuroblastoma cell line that reportedly has NC-like features, seeded on the extracellular matrix of PDL cells for 2 weeks, resulted in the significant upregulation of PDL marker expression. SK-N-SH cell-derived PDLSCs (SK-PDLSCs) presented phenotypic characteristics comparable to induced pluripotent stem cell (iPSC)-derived PDLSCs (iPDLSCs). The expression levels of various hyaluronic acid (HA)-related genes were upregulated in iPDLSCs and SK-PDLSCs compared with iPSC-derived NCs and SK-N-SH cells, respectively. The knockdown of CD44 in SK-N-SH cells significantly inhibited their ability to differentiate into SK-PDLSCs, while low-molecular HA (LMWHA) induction enhanced SK-PDLSC differentiation. Our findings suggest that SK-N-SH cells could be applied as a new model to induce the differentiation of NCs into PDLSCs and that the LMWHA-CD44 relationship is important for the differentiation of NCs into PDLSCs.