Checkpoint CD24 function on tumor and immunotherapy.

CD24 is a protein found on the surface of cells that plays a crucial role in the proliferation, invasion, and spread of cancer cells. It adheres to cell membranes through glycosylphosphatidylinositol (GPI) and is associated with the prognosis and survival rate of cancer patients. CD24 interacts with the inhibitory receptor Siglec-10 that is present on immune cells like natural killer cells and macrophages, leading to the inhibition of natural killer cell cytotoxicity and macrophage-mediated phagocytosis. This interaction helps tumor cells escape immune detection and attack. Although the use of CD24 as a immune checkpoint receptor target for cancer immunotherapy is still in its early stages, clinical trials have shown promising results. Monoclonal antibodies targeting CD24 have been found to be well-tolerated and safe. Other preclinical studies are exploring the use of chimeric antigen receptor (CAR) T cells, antibody-drug conjugates, and gene therapy to target CD24 and enhance the immune response against tumors. In summary, this review focuses on the role of CD24 in the immune system and provides evidence for CD24 as a promising immune checkpoint for cancer immunotherapy.

CD24 negativity reprograms mitochondrial metabolism to PPARα and NF-κB-driven fatty acid ß-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.

The Oncolytic Activity of Zika Viral Therapy in Human Neuroblastoma In Vivo Models Confers a Major Survival Advantage in a CD24-dependent Manner.

Neuroblastoma is the most common extracranial tumor, accounting for 15% of all childhood cancer-related deaths. The long-term survival of patients with high-risk tumors is less than 40%, and MYCN amplification is one of the most common indicators of poor outcomes. Zika virus (ZIKV) is a mosquito-borne flavivirus associated with mild constitutional symptoms outside the fetal period. Our published data showed that high-risk and recurrent neuroblastoma cells are permissive to ZIKV infection, resulting in cell type-specific lysis. In this study, we assessed the efficacy of ZIKV as an oncolytic treatment for high-risk neuroblastoma using in vivo tumor models. Utilizing both MYCN-amplified and non-amplified models, we demonstrated that the application of ZIKV had a rapid tumoricidal effect. This led to a nearly total loss of the tumor mass without evidence of recurrence, offering a robust survival advantage to the host. Detection of the viral NS1 protein within the tumors confirmed that a permissive infection preceded tissue necrosis. Despite robust titers within the tumor, viral shedding to the host was poor and diminished rapidly, correlating with no detectable side effects to the murine host. Assessments from both primary pretreatment and recurrent posttreatment isolates confirmed that permissive sensitivity to ZIKV killing was dependent on the expression of CD24, which was highly expressed in neuroblastomas and conferred a proliferative advantage to tumor growth. Exploiting this viral sensitivity to CD24 offers the possibility of its use as a prognostic target for a broad population of expressing cancers, many of which have shown resistance to current clinical therapies. SIGNIFICANCE: Sensitivity to the tumoricidal effect of ZIKV on high-risk neuroblastoma tumors is dependent on CD24 expression, offering a prognostic marker for this oncolytic therapy in an extensive array of CD24-expressing cancers.

High Expression and Significance of Siglec10/CD24 in Unexplained Missed Abortion.

OBJECTIVE: To investigate the expression of Siglec10 and CD24 in normal early pregnancy and missed abortion, and their significance in the maternal-fetal interface. METHODS: For our research, we employed Q-PCR and WB techniques to evaluate the traits and expression of Siglec10 and CD24 in the nonpregnant endometrium, as well as in the villus and decidua of women in their 6-10 weeks of normal early pregnancy and those who experienced missed abortion. Additionally, we utilized ELISA to determine the levels of Siglec10 and CD24 in the peripheral blood of pregnancy, missed abortion, and non-pregnant individuals. T-test and ANOVA were used to compare groups. RESULTS: 1. Villous tissues in early pregnancy showed high expression of Siglec10 and CD24, with a significant increase in expression in the missed abortion group (P < 0.01).2. Nonpregnant endometrial tissue showed low expression of Siglec10 and CD24, while early pregnancy decidua showed high expression, with even higher expression in missed abortion (all P < 0.05).3. Serum levels of Siglec10 and CD24 in normal early pregnancy were significantly higher than non-pregnancy (P < 0.01). However, the missed abortion group showed significantly higher levels than normal pregnancy (P < 0.01).4. CD24 expression in serum of missed abortion increases with Siglec10 expression, indicating a significant positive correlation (r = 0.500, P < 0.01). CONCLUSION: Siglec10 and CD24 expression in villus, decidua, and peripheral blood are up-regulated in unexplained missed abortions than those of women with normal pregnancies. This suggests that the levels of serum Siglec10 and CD24 can be used as an effective predictor of missed abortion.

Attenuated Salmonella carrying siRNA-CD24 improved the effect of oxaliplatin on HCC.

Oxaliplatin is a chemotherapy drug currently utilized in the treatment of advanced cancer patients. However, its tolerability poses a limitation to its clinical application. Studies have demonstrated that the presence of tumor-associated macrophages is positively correlated with poor prognosis in various solid tumors, including hepatocellular carcinoma (HCC), and is a significant factor contributing to oxaliplatin resistance. Therefore, targeting tumor-associated macrophages may be an effective strategy to improve the efficacy of oxaliplatin in the treatment of HCC patients. CD24 is a novel target for tumor therapy that can interact with the inhibitory receptor Siglec-10 on tumor-associated macrophages, transmitting immune inhibitory signals and inhibiting macrophage phagocytosis function. In this study, we utilized RNAi technology to inhibit the expression of CD24 in tumor cells and combined it with oxaliplatin, resulting in reduced tumor invasion, migration, and proliferation, as well as increased cell apoptosis. Furthermore, immunofluorescence and flow cytometry results indicated that both the single treatment group and combination treatment group enhanced the infiltration of immune cells. This study presents a novel approach to identifying combination therapy and targets for the clinical treatment of HCC with oxaliplatin.

CD24 targeting with NK-CAR immunotherapy in testis, prostate, renal and (luminal-type) bladder cancer and identification of direct CD24 interaction partners.

Alternative therapeutic options targeting urologic malignancies, such as germ cell tumours, as well as urothelial, renal and prostate carcinomas, are still urgently needed. The membrane protein CD24 represents a promising immunotherapeutical approach. The present study aimed to decipher the molecular function of CD24 in vitro and evaluate the cytotoxic capacity of a third-generation natural killer (NK) cell chimeric antigen receptor (CAR) against CD24 in urologic tumour cell lines. Up to 20 urologic tumour cell lines and several non-malignant control cells were included. XTT viability assays and annexin V/propidium iodide flow cytometry analyses were performed to measure cell viability and apoptosis rates, respectively. Co-immunoprecipitation followed by mass spectrometry analyses identified direct interaction partners of CD24. Luciferase reporter assays were used to functionally validate transactivation of CD24 expression by SOX2. N- and O-glycosylation of CD24 were evaluated by enzymatic digestion and mass spectrometry. The study demonstrates that SOX2 transactivates CD24 expression in embryonal carcinoma cells. In cells of different urological origins, CD24 interacted with proteins involved in cell adhesion, ATP binding, phosphoprotein binding and post-translational modifications, such as histone acetylation and ubiquitination. Treatment of urological tumour cells with NK-CD24-CAR cells resulted in a decreased cell viability and apoptosis induction specifically in CD24+ tumour cells. Limitations of the study include the in vitro setting, which still has to be confirmed in vivo. In conclusion, we show that CD24 is a promising novel target for immune therapeutic approaches targeting urologic malignancies.

[Expression of CD24 gene in human malignant pleural mesothelioma and its relationship with prognosis].

Objective: To investigate the expression of CD24 gene in human malignant pleural mesothelioma (MPM) cells and tissues, and evaluate its relationship with clinicopathological characteristics and clinical prognosis of MPM patients. Methods: In February 2021, UALCAN database was used to analyze the correlation between CD24 gene expression and clinicopathological characteristics in 87 cases of MPM patients. The TIMER 2.0 platform was used to explore the relationship between the expression of CD24 in MPM and tumor immune infiltrating cells. cBioportal online tool was used to analyze the correlation between CD24 and MPM tumor marker gene expression. RT-qPCR was used to analyze the expressions of CD24 gene in human normal pleural mesothelial cell lines LP9 and MPM cell lines NCI-H28 (epithelial type), NCI-H2052 (sarcoma type), and NCI-H2452 (biphasic mixed type). RT-qPCR was performed to detect the expressions of CD24 gene in 18 cases of MPM tissues and matched normal pleural tissues. The expression difference of CD24 protein in normal mesothelial tissue and MPM tissue was analyzed by immunohistochemistry. A Kaplan-Meier model was constructed to explore the influence of CD24 gene expression on the prognosis of MPM patients, and Cox regression analysis of prognostic factors in MPM patients was performed. Results: The CD24 gene expression without TP53 mutation MPM patients was significantly higher than that of patients in TP53 mutation (P<0.05). The expression of CD24 gene in MPM was positively correlated with B cells (r(s)=0.37, P<0.001). The expression of CD24 gene had a positive correlation with the expressions of thrombospondin 2 (THBS2) (r(s)=0.26, P<0.05), and had a negative correlation with the expression of epidermal growth factor containing fibulin like extracellular matrix protein 1 (EFEMP1), mesothelin (MSLN) and calbindin 2 (CALB2) (r(s)=-0.31, -0.52, -0.43, P<0.05). RT-qPCR showed that the expression level of CD24 gene in MPM cells (NCI-H28, NCI-H2052 and NCI-H2452) was significantly higher than that in normal pleural mesothelial LP9 cells. The expression level of CD24 gene in MPM tissues was significantly higher than that in matched normal pleural tissues (P<0.05). Immunohistochemistry showed that the expressions of CD24 protein in epithelial and sarcoma MPM tissues were higher than those of matched normal pleural tissues. Compared with low expression of CD24 gene, MPM patients with high expression of CD24 gene had lower overall survival (HR=2.100, 95%CI: 1.336-3.424, P<0.05) and disease-free survival (HR=1.800, 95%CI: 1.026-2.625, P<0.05). Cox multivariate analysis showed that compared with the biphasic mixed type, the epithelial type was a protective factor for the prognosis of MPM patients (HR=0.321, 95%CI: 0.172-0.623, P<0.001). Compared with low expression of CD24 gene, high expression of CD24 gene was an independent risk factor for the prognosis of MPM patients (HR=2.412, 95%CI: 1.291-4.492, P=0.006) . Conclusion: CD24 gene and protein are highly expressed in MPM tissues, and the high expression of CD24 gene suggests poor prognosis in MPM patients.

CD24-associated ceRNA network reveals prognostic biomarkers in breast carcinoma.

Breast cancer is one of the most common cancer types which is described as the leading cause of cancer death in women. After competitive endogenous RNA (ceRNA) hypothesis was proposed, this triple regulatory network has been observed in various cancers, and increasing evidences reveal that ceRNA network plays a significant role in the migration, invasion, proliferation of cancer cells. In the current study, our target is to construct a CD24-associated ceRNA network, and to further identify key prognostic biomarkers in breast cancer. Using the transcriptom profiles from TCGA database, we performed a comprehensive analysis between CD24high tumor samples and CD24low tumor samples, and identified 132 DElncRNAs, 602 DEmRNAs and 26 DEmiRNAs. Through comprehensive analysis, RP1-228H13.5/miR-135a-5p/BEND3 and SIM2 were identified as key CD24-associated biomarkers, which exhibited highly significance with overall survival, immune microenvironment as well as clinical features. To sum up the above, the current study constructed a CD24-associated ceRNA network, and RP1-228H13.5/miR-135a-5p/BEND3 and SIM2 axis worked as a potential therapeutic target and a predictor for BRCA diagnosis and prognosis.

CD24+CD44+CD54+EpCAM+ gastric cancer stem cells predict tumor progression and metastasis: clinical and experimental evidence.

BACKGROUND: Gastric cancer (GC) is a leading cause of cancer-related deaths worldwide. Specific and thorough identification of cancer cell subsets with higher tumorigenicity and chemoresistance, such as cancer stem cells (CSCs), could lead to the development of new and promising therapeutic targets. For better CSC identification, a complete or extended surface marker phenotype is needed to provide increased specificity for new cell targeting approaches. Our goal is to identify and characterize a putative extended phenotype for CSCs derived from patients with GC before treatment, as well as to evaluate its clinical value. In addition, we aim to ensure that cells with this phenotype have stemness and self-renewal capabilities. METHODS: This is a cohort study including 127 treatment-naïve patients with GC who attended the Instituto Nacional de Cancerología. Multiparametric flow cytometry analysis was performed to determine the extended phenotype of cells derived from gastric biopsies. The tumorigenic capability of cells identified in patients was assessed in a zebrafish model. RESULTS: CD24+CD44+CD54+EpCAM+ cells were present in all treatment-naïve patients included, with a median abundance of 1.16% (0.57-1.89%). The percentage of CD24+CD44+CD54+EpCAM+ cells was categorized as high or low using 1.19% as the cutoff for the CD24+CD44+CD54+EpCAM+ cell subset. Additionally, a higher TNM stage correlated with a higher percentage of CD24+CD44+CD54+EpCAM+ cells (Rho coefficient 0.369; p < 0.0001). We also demonstrated that a higher percentage of CD24+CD44+CD54+EpCAM+ cells was positively associated with metastasis. The metastatic potential of these cells was confirmed in a zebrafish model. Ultimately, under our conditions, we conclude that CD24+CD44+CD54+EpCAM+ cells are true gastric cancer stem cells (GCSCs). CONCLUSION: The CD24+CD44+CD54+EpCAM+ cells present in tissue samples from patients are true GCSCs. This extended phenotype results in better and more specific characterization of these highly tumorigenic cells. The relative quantification of CD24+CD44+CD54+EpCAM+ cells has potential clinical value, as these cells are associated with metastatic disease, making their presence an additional prognostic marker and possibly a target for the design of new antineoplastic treatments in the era of precision oncology. Overall, the extended CD24+CD44+CD54+EpCAM+ phenotype of GCSCs could support their isolation for the study of their stemness mechanisms, leading to the identification of better molecular targets for the development of both new therapeutic approaches such as oncoimmunotherapy and new diagnostic and clinical prognostic strategies for GC.

GATA3 Encapsulated by Tumor-Associated Macrophage-Derived Extracellular Vesicles Promotes Immune Escape and Chemotherapy Resistance of Ovarian Cancer Cells by Upregulating the CD24/Siglec-10 Axis.

Tumor-associated macrophages (TAMs) possess great potential in the development of ovarian cancer (OC). Aberrant GATA-binding protein-3 (GATA3) expression has been found in TAM-derived extracellular vesicles (EVs). This study is intended to investigate the regulatory mechanism of TAM-derived EVs, expressing GATA3 in immune escape and chemotherapy resistance of OC cells. In silico analysis was employed to identify differentially expressed genes. The expression of GATA3, CD24, and sialic acid-binding igg-like lectin 10 (Siglec-10) in OC tissues and cells was characterized, with their correlation verified. OC cells were co-cultured with TAM-derived EVs and CD8+T cells. The functional significance of GATA3/CD24/Siglec-10 in immune escape and chemotherapy resistance of OC cells was assayed by the gain and loss of function experiments. In vivo experiments were also performed for further validation. High expressions of GATA3, CD24, and Siglec-10 were observed in OC tissues and cells. GATA3 could be transferred by TAM-derived EVs into OC cells, which facilitated immune escape and resistance to cisplatin of OC cells. GATA3 up-regulated CD24 to increase Siglec-10 expression. The in vivo assay confirmed the promoting effect of GATA3 delivered by TAM-derived EVs on OC through activation of the CD24/Siglec-10 axis. Collectively, TAM-derived EVs harboring GATA3 played a tumor-promoting role in immune escape and chemotherapy resistance of OC cells via the CD24/Siglec-10 axis.

A highly potent small-molecule antagonist of exportin-1 selectively eliminates CD44+CD24- enriched breast cancer stem-like cells.

Breast cancer stem-like cells (BCSCs) have been suggested as the underlying cause of tumor recurrence, metastasis and drug resistance in triple-negative breast cancer (TNBC). Here, we report the discovery and biological evaluation of a highly potent small-molecule antagonist of exportin-1, LFS-1107. We ascertained that exportin-1 (also named as CRM1) is a main cellular target of LFS-1107 by nuclear export functional assay, bio-layer interferometry binding assay and C528S mutant cell line. We found that LFS-1107 significantly inhibited TNBC tumor cells at low-range nanomolar concentration and LFS-1107 can selectively eliminate CD44+CD24- enriched BCSCs. We demonstrated that LFS-1107 can induce the nuclear retention of Survivin and consequent strong suppression of STAT3 transactivation abilities and the expression of downstream stemness regulators. Administration of LFS-1107 can strongly inhibit tumor growth in mouse xenograft model and eradicate BCSCs in residual tumor tissues. Moreover, LFS-1107 can significantly ablate the patient-derived tumor organoids (PDTOs) of TNBC as compared to a few approved cancer drugs. Lastly, we revealed that LFS-1107 can enhance the killing effects of chemotherapy drugs and downregulate multidrug resistance related protein targets. These new findings provide preclinical evidence of defining LFS-1107 as a promising therapeutic agent to deplete BCSCs for the treatment of TNBC.

Loss of CD24 promotes radiation­ and chemo­resistance by inducing stemness properties associated with a hybrid E/M state in breast cancer cells.

Cancer stem cells (CSCs) serve an essential role in failure of conventional antitumor therapy. In breast cancer, CD24­/low/CD44+ phenotype and high aldehyde dehydrogenase activity are associated with CSC subtypes. Furthermore, CD24­/low/CD44+ pattern is also characteristic of mesenchymal cells generated by epithelial­mesenchymal transition (EMT). CD24 is a surface marker expressed in numerous types of tumor, however, its biological functions and role in cancer progression and treatment resistance remain poorly documented. Loss of CD24 expression in breast cancer cells is associated with radiation resistance and control of oxidative stress. Reactive oxygen species (ROS) mediate the effects of anticancer drugs as well as ionizing radiation; therefore, the present study investigated if CD24 mediates radiation­ and chemo­resistance of breast cancer cells. Using a HMLE breast cancer cell model, CD24 expression has been artificially modulated and it was observed that loss of CD24 expression induced stemness properties associated with acquisition of a hybrid E/M phenotype. CD24­/low cells were more radiation­ and chemo­resistant than CD24+ cells. The resistance was associated with lower levels of ROS; CD24 controlled ROS levels via regulation of mitochondrial function independently of antioxidant activity. Together, these results suggested a key role of CD24 in de­differentiation of breast cancer cells and promoting acquisition of therapeutic resistance properties.

Expression of CD24 gene in human malignant pleural mesothelioma and its relationship with prognosis / 中华劳动卫生职业病杂志

Objective: To investigate the expression of CD24 gene in human malignant pleural mesothelioma (MPM) cells and tissues, and evaluate its relationship with clinicopathological characteristics and clinical prognosis of MPM patients. Methods: In February 2021, UALCAN database was used to analyze the correlation between CD24 gene expression and clinicopathological characteristics in 87 cases of MPM patients. The TIMER 2.0 platform was used to explore the relationship between the expression of CD24 in MPM and tumor immune infiltrating cells. cBioportal online tool was used to analyze the correlation between CD24 and MPM tumor marker gene expression. RT-qPCR was used to analyze the expressions of CD24 gene in human normal pleural mesothelial cell lines LP9 and MPM cell lines NCI-H28 (epithelial type), NCI-H2052 (sarcoma type), and NCI-H2452 (biphasic mixed type). RT-qPCR was performed to detect the expressions of CD24 gene in 18 cases of MPM tissues and matched normal pleural tissues. The expression difference of CD24 protein in normal mesothelial tissue and MPM tissue was analyzed by immunohistochemistry. A Kaplan-Meier model was constructed to explore the influence of CD24 gene expression on the prognosis of MPM patients, and Cox regression analysis of prognostic factors in MPM patients was performed. Results: The CD24 gene expression without TP53 mutation MPM patients was significantly higher than that of patients in TP53 mutation (P<0.05). The expression of CD24 gene in MPM was positively correlated with B cells (r(s)=0.37, P<0.001). The expression of CD24 gene had a positive correlation with the expressions of thrombospondin 2 (THBS2) (r(s)=0.26, P<0.05), and had a negative correlation with the expression of epidermal growth factor containing fibulin like extracellular matrix protein 1 (EFEMP1), mesothelin (MSLN) and calbindin 2 (CALB2) (r(s)=-0.31, -0.52, -0.43, P<0.05). RT-qPCR showed that the expression level of CD24 gene in MPM cells (NCI-H28, NCI-H2052 and NCI-H2452) was significantly higher than that in normal pleural mesothelial LP9 cells. The expression level of CD24 gene in MPM tissues was significantly higher than that in matched normal pleural tissues (P<0.05). Immunohistochemistry showed that the expressions of CD24 protein in epithelial and sarcoma MPM tissues were higher than those of matched normal pleural tissues. Compared with low expression of CD24 gene, MPM patients with high expression of CD24 gene had lower overall survival (HR=2.100, 95%CI: 1.336-3.424, P<0.05) and disease-free survival (HR=1.800, 95%CI: 1.026-2.625, P<0.05). Cox multivariate analysis showed that compared with the biphasic mixed type, the epithelial type was a protective factor for the prognosis of MPM patients (HR=0.321, 95%CI: 0.172-0.623, P<0.001). Compared with low expression of CD24 gene, high expression of CD24 gene was an independent risk factor for the prognosis of MPM patients (HR=2.412, 95%CI: 1.291-4.492, P=0.006) . Conclusion: CD24 gene and protein are highly expressed in MPM tissues, and the high expression of CD24 gene suggests poor prognosis in MPM patients.

Modeling Preeclampsia In Vitro: Polymorphic Variants of STOX1-A/B Genes Can Downregulate CD24 in Trophoblast Cell Lines.

CD24 is a mucin-like immunosuppressing glycoprotein whose levels increase during pregnancy and decrease in the syncytio- and cytotrophoblasts in early and preterm preeclampsia. We used two modified cell lines that mimic in vitro features of preeclampsia to identify if this phenomenon could be reproduced. Our model was the immortalized placental-derived BeWo and JEG-3 cell lines that overexpress the STOX1 A/B transcription factor gene that was discovered in familial forms of preeclampsia. BeWo and JEG-3 cells stably transduced with the two major isoforms of STOX1-A/B or by an empty vector (control), were propagated, harvested, and analyzed. CD24 mRNA expression was determined by quantitative real-time polymerase nuclear chain reaction (qRT-PCR). CD24 protein levels were determined by Western blots. In STOX1-A/B overexpressing in BeWo cells, CD24 mRNA was downregulated by 91 and 85%, respectively, compared to the control, and by 30% and 74%, respectively in JEG-3 cells. A 67% and 82% decrease in CD24 protein level was determined by immunoblot in BeWo overexpressing STOX1-A/B, respectively, while the reduction in JEG-3 cells was between 47 and 62%. The immortalized BeWo and JEG-3 cell lines overexpressing STOX1-A/B had reduced CD24. Although both cell lines were affected, BeWo appears to be more susceptible to downregulation by STOX-1 than JEG-3, potentially because of their different cell origin and properties. These results strengthen the in vivo results of reduced CD24 levels found in early and preterm preeclampsia. Accordingly, it implies the importance of the reduced immune tolerance in preeclampsia, which was already demonstrated in vivo in the STOX1-A/B model of preeclampsia, and is now implied in the in vitro STOX-1 model, a subject that warrants further investigations.

Adult human kidney organoids originate from CD24+ cells and represent an advanced model for adult polycystic kidney disease.

Adult kidney organoids have been described as strictly tubular epithelia and termed tubuloids. While the cellular origin of tubuloids has remained elusive, here we report that they originate from a distinct CD24+ epithelial subpopulation. Long-term-cultured CD24+ cell-derived tubuloids represent a functional human kidney tubule. We show that kidney tubuloids can be used to model the most common inherited kidney disease, namely autosomal dominant polycystic kidney disease (ADPKD), reconstituting the phenotypic hallmark of this disease with cyst formation. Single-cell RNA sequencing of CRISPR-Cas9 gene-edited PKD1- and PKD2-knockout tubuloids and human ADPKD and control tissue shows similarities in upregulation of disease-driving genes. Furthermore, in a proof of concept, we demonstrate that tolvaptan, the only approved drug for ADPKD, has a significant effect on cyst size in tubuloids but no effect on a pluripotent stem cell-derived model. Thus, tubuloids are derived from a tubular epithelial subpopulation and represent an advanced system for ADPKD disease modeling.

CD44+/CD24- Expression as predictors of ovarian cancer chemoresistance: immunohistochemistry and flow cytometry study.

BACKGROUND: The conventional standard treatment for ovarian cancer is not very effective, and the disease is fatal for women. Cancer Stem Cells (CSCs) that express CD44+/CD24- can contribute to chemoresistance and a poor prognosis. We seek to investigate the expression of CSCs (CD44+/CD24-) in ovarian cancer and their predictive significance. METHODS: The ambispective cohort was performed on 64 patients (32 patients in each group) at four hospitals (Cipto Mangunkusumo, Tarakan, Fatmawati, and Dharmais Hospital). Debulking surgery was performed on the patients, followed by histopathological analysis. The patients had six rounds of chemotherapy and were under monitoring for six months. The therapeutic responses were evaluated using the RECIST criteria (Response Criteria in Solid Tumors) and categorized as chemoresistant or chemosensitive. Using immunohistochemistry, we directly assess the CSCs from ovarian cancer tissue and using flow cytometry to assess the CSCs from the blood. RESULTS: High CSCs expression and ovarian cancer chemoresistance were significantly related in both trials (p 0.05). A better outcome was obtained using CD44+/CD24- immunohistochemistry. CONCLUSIONS: We conclude that there is a substantial association between high CSCs expression and chemoresistance in ovarian cancer and that CSCs immunohistochemistry has a higher predictive value.

CD24-Siglec axis is an innate immune checkpoint against metaflammation and metabolic disorder.

The molecular interactions that regulate chronic inflammation underlying metabolic disease remain largely unknown. Since the CD24-Siglec interaction regulates inflammatory response to danger-associated molecular patterns (DAMPs), we have generated multiple mouse strains with single or combined mutations of Cd24 or Siglec genes to explore the role of the CD24-Siglec interaction in metaflammation and metabolic disorder. Here, we report that the CD24-Siglec-E axis, but not other Siglecs, is a key suppressor of obesity-related metabolic dysfunction. Inactivation of the CD24-Siglec-E pathway exacerbates, while CD24Fc treatment alleviates, diet-induced metabolic disorders, including obesity, dyslipidemia, insulin resistance, and nonalcoholic steatohepatitis (NASH). Mechanistically, sialylation-dependent recognition of CD24 by Siglec-E induces SHP-1 recruitment and represses metaflammation to protect against metabolic syndrome. A first-in-human study of CD24Fc (NCT02650895) supports the significance of this pathway in human lipid metabolism and inflammation. These findings identify the CD24-Siglec-E axis as an innate immune checkpoint against metaflammation and metabolic disorder and suggest a promising therapeutic target for metabolic disease.

Prognosis assessment of CD44+/CD24- in breast cancer patients: a systematic review and meta-analysis.

PURPOSE: This meta-analysis investigated the relationships between the CD44+/CD24- phenotype and tumor size, lymph node metastasis, distant metastasis, disease-free survival (DFS), and overall survival (OS) in 8036 postoperative breast cancer patients enrolled in 23 studies. METHODS: A literature search of PubMed, Medline, Cochrane, Embase, and PMC was conducted to identify eligible studies. The combined odds ratios (ORs) and 95% confidence intervals (95% CIs) were analyzed to evaluate the relationships between the CD44+/CD24- phenotype and the pathological and biological characteristics of breast cancer patients, and the combined hazard ratios (HRs) and 95% CIs were calculated to evaluate the relationships between CD44+/CD24- and DFS and OS of breast cancer patients using Stata12.0 software. RESULTS: The CD44+/CD24- phenotype were not related to the tumor size (tumor size > 2.0 vs ≤ 2.0 cm, combined OR = 0.98, 95% CI 0.68-1.34, p = 0.792) and did not promote lymph node metastasis (lymph node metastasis vs. no lymph node metastasis, OR = 0.92, 95% CI 0.67-1.27, p = 0.626) and distant metastasis (distant metastasis vs no distant metastasis, combined OR = 3.88, 95% CI 0.93-16.24, p = 0.064). The CD44+/CD24- phenotype was negatively correlated with postoperative DFS (HR = 1.67, 95% CI 1.35-2.07, p < 0.00001) and OS (combined HR = 1.52, 95% CI 1.21-1.91, p = 0.0004). CONCLUSION: These results suggested expression of the CD44+/CD24- phenotype cannot be used as a reliable indicator of the tumor size, lymph node metastasis, and distant metastasis, however, it can be used be a potential therapeutic targets of DFS, OS in breast cancer patients.

Phenotypic and molecular states of IDH1 mutation-induced CD24-positive glioma stem-like cells.

Mutations in IDH1 and IDH2 drive the development of gliomas. These genetic alterations promote tumor cell renewal, disrupt differentiation states, and induce stem-like properties. Understanding how this phenotypic reprogramming occurs remains an area of high interest in glioma research. Previously, we showed that IDH mutation results in the development of a CD24-positive cell population in gliomas. Here, we demonstrate that this CD24-positive population possesses striking stem-like properties at the molecular and phenotypic levels. We found that CD24 expression is associated with stem-like features in IDH-mutant tumors, a patient-derived gliomasphere model, and a neural stem cell model of IDH1-mutant glioma. In orthotopic models, CD24-positive cells display enhanced tumor initiating potency compared to CD24-negative cells. Furthermore, CD24 knockdown results in changes in cell viability, proliferation rate, and gene expression that closely resemble a CD24-negative phenotype. Our data demonstrate that induction of a CD24-positive population is one mechanism by which IDH-mutant tumors acquire stem-like properties. These findings have significant implications for our understanding of the molecular underpinnings of IDH-mutant gliomas.

CD24 is a surrogate for 'immune-cold' phenotype in aggressive large B-cell lymphoma.

The tumor microenvironment (TME) is a critical regulator of the development of malignant lymphoma. Therapeutics targeting the TME, especially immune checkpoint molecules, are changing the treatment strategy for lymphoma. However, the overall response to these therapeutics for diffuse large B-cell lymphoma (DLBCL) is modest and new targets of immunotherapy are needed. To find critical immune checkpoint molecules for DLBCL, we explored the prognostic impact of immune checkpoint molecules and their ligands using publicly available datasets of gene expression profiles. In silico analysis of three independent datasets (GSE117556, GSE10846, and GSE181063) revealed that DLBCL expressing CD24 had a poor prognosis and had a high frequency of MYC aberrations. Moreover, gene set enrichment analysis showed that the 'MYC-targets-hallmark' (false discovery rate [FDR] = 0.024) and 'inflammatory-response-hallmark' (FDR = 0.001) were enriched in CD24-high and CD24-low DLBCL, respectively. In addition, the expression of cell-specific markers of various immune cells was higher in CD24-low DLBCL than in CD24-high DLBCL. CIBERSORT analysis of the datasets showed fewer macrophages in CD24-high DLBCL than in CD24-low DLBCL. Additionally, immunohistochemical analysis of 335 cases of DLBCL showed that few TME cells were found in CD24-high DLBCL, although statistical differences were not observed. These data indicate that CD24 expression suppresses immune cell components of the TME in DLBCL, suggesting that CD24 may be a target for cancer immunotherapy in aggressive large B-cell lymphoma.