CD24 expression as a marker for predicting clinical outcome in human gliomas

From mechanism to therapy: the journey of CD24 in cancer

CD24 is a glycosylphosphatidylinositol-anchored protein that is expressed in a wide range of tissues and cell types. It is involved in a variety of physiological and pathological processes, including cell adhesion, migration, differentiation, and apoptosis. Additionally, CD24 has been studied extensively in the context of cancer, where it has been found to play a role in tumor growth, invasion, and metastasis. In recent years, there has been growing interest in CD24 as a potential therapeutic target for cancer treatment. This review summarizes the current knowledge of CD24, including its structure, function, and its role in cancer. Finally, we provide insights into potential clinical application of CD24 and discuss possible approaches for the development of targeted cancer therapies.

New Visions on Natural Products and Cancer Therapy: Autophagy and Related Regulatory Pathways

Macroautophagy (autophagy) has been a highly conserved process throughout evolution and allows cells to degrade aggregated/misfolded proteins, dysfunctional or superfluous organelles and damaged macromolecules, in order to recycle them for biosynthetic and/or energetic purposes to preserve cellular homeostasis and health. Changes in autophagy are indeed correlated with several pathological disorders such as neurodegenerative and cardiovascular diseases, infections, cancer and inflammatory diseases. Conversely, autophagy controls both apoptosis and the unfolded protein response (UPR) in the cells. Therefore, any changes in the autophagy pathway will affect both the UPR and apoptosis. Recent evidence has shown that several natural products can modulate (induce or inhibit) the autophagy pathway. Natural products may target different regulatory components of the autophagy pathway, including specific kinases or phosphatases. In this review, we evaluated ~100 natural compounds and plant species and their impact on different types of cancers via the autophagy pathway. We also discuss the impact of these compounds on the UPR and apoptosis via the autophagy pathway. A multitude of preclinical findings have shown the function of botanicals in regulating cell autophagy and its potential impact on cancer therapy; however, the number of related clinical trials to date remains low. In this regard, further pre-clinical and clinical studies are warranted to better clarify the utility of natural compounds and their modulatory effects on autophagy, as fine-tuning of autophagy could be translated into therapeutic applications for several cancers.

Combinatorial delivery of CPI444 and vatalanib loaded on PEGylated graphene oxide as an effective nanoformulation to target glioblastoma multiforme: In vitro evaluation

Glioblastoma multiforme (GBM) is known as the primary malignant and most devastating form of tumor found in the central nervous system of the adult population. The active pharmaceutical component in current chemotherapy regimens is mostly hydrophobic and poorly water-soluble, which hampers clinical implications. Nanodrug formulations using nanocarriers loaded with such drugs assisted in water dispersibility, improved cellular permeability, and drug efficacy at a low dose, thus adding to the overall practical value. Here, we successfully developed a water-dispersible and biocompatible nanocargo (GO-PEG) based on covalently modified graphene oxide (GO) with a 6-armed poly(ethylene glycol) amine dendrimer for effective loading of the two hydrophobic anticancer drug molecules, CPI444 and vatalanib. These drug molecules target adenosine receptor (A2AR), vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and type III stem cell receptor tyrosine kinase (c-KIT), which plays a crucial role in cancers. The effective cellular delivery of the drugs when loaded on GO-PEG is attributed to the increased permeability of the drug-nanoconjugate formulation. We observed that this combinatorial drug treatment with nanocargo resulted in a significant reduction in the overall cell survival as supported by reduced calcium levels and stem cell markers such as Oct4 and Nanog, which are two of the prime factors for GBM stem cell proliferation. Furthermore, reduced expression of CD24 upon treatment with nanoformulation impeded cellular migration. Cellular assays confirmed inhibition of cell proliferation, migration, and angiogenic potential of GBM treated with GO-PEG–Drug conjugates. Ultimately, GBM U87 cells assumed programmed cell death at a very low concentration due to nanocarrier-mediated drug delivery along with the chosen combination of drugs. Together, this study demonstrated the advantage of GO-PEG mediated combined delivery of CPI444 and vatalanib drugs with increased permeability, a three-pronged combinatorial strategy toward effective GBM treatment.

Macrophages in Glioblastoma Development and Therapy: A Double-Edged Sword

Glioblastoma (GBM) is one of the leading lethal tumors, featuring aggressive malignancy and poor outcome to current standard temozolomide (TMZ) or radio-based therapy. Developing immunotherapies, especially immune checkpoint inhibitors, have improved patient outcomes in other solid tumors but remain fatigued in GBM patients. Emerging evidence has shown that GBM-associated macrophages (GAMs), comprising brain-resident microglia and bone marrow-derived macrophages, act critically in boosting tumor progression, altering drug resistance, and establishing an immunosuppressive environment. Based on its crucial role, evaluations of the safety and efficacy of GAM-targeted therapy are ongoing, with promising (pre)clinical evidence updated. In this review, we summarized updated literature related to GAM nature, the interplay between GAMs and GBM cells, and GAM-targeted therapeutic strategies.

Review: New horizons in retinoblastoma treatment: an updated review article

Retinoblastoma (Rb) is a rare childhood intraocular malignancy with an incidence rate of approximately 9000 children per year worldwide. The management of Rb is inherently complex and depends on several factors. The orders of priorities in the treatment of Rb are saving life, globe salvage and vision salvage. Rarity and the young age at diagnosis impede conducting randomized clinical trials (RCTs) for new therapeutic options, and therefore pre-RCTs studies are needed. This review provides an overview of advances in Rb treatment options, focusing on the emergence of new small molecules to treat Rb. Articles related to the management and treatments of Rb were searched in different databases. Several studies and animal models discussing recent advances in the treatment of Rb were included to have a better grasp of the biological mechanisms of Rb. Over the years, the principles of management and treatment of Rb have changed significantly. Innovations in targeted therapies and molecular biology have led to improved patient and ocular survival. However, there is still a need for further evaluation of the long-term effects of these new treatments.

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.

Angiogenin and plexin-B2 axis promotes glioblastoma progression by enhancing invasion, vascular association, proliferation and survival

BACKGROUND

Angiogenin is a multifunctional secreted ribonuclease that is upregulated in human cancers and downregulated or mutationally inactivated in neurodegenerative diseases. A role for angiogenin in glioblastoma was inferred from the inverse correlation of angiogenin expression with patient survival but had not been experimentally investigated.

METHODS

Angiogenin knockout mice were generated and the effect of angiogenin deficiency on glioblastoma progression was examined. Angiogenin and plexin-B2 genes were knocked down in glioblastoma cells and the changes in cell proliferation, invasion and vascular association were examined. Monoclonal antibodies of angiogenin and small molecules were used to assess the therapeutic activity of the angiogenin-plexin-B2 pathway in both genetic and xenograft animal models.

RESULTS

Deletion of Ang1 gene prolonged survival of PDGF-induced glioblastoma in mice in the Ink4a/Arf^-/-:Pten^-/- background, accompanied by decreased invasion, vascular association and proliferation. Angiogenin upregulated MMP9 and CD24 leading to enhanced invasion and vascular association. Inhibition of angiogenin or plexin-B2, either by shRNA, monoclonal antibody or small molecule inhibitor, decreases sphere formation of patient-derived glioma stem cells, reduces glioblastoma proliferation and invasion and inhibits glioblastoma growth in both genetic and xenograft animal models.

CONCLUSIONS

Angiogenin and its receptor, plexin-B2, are a pair of novel regulators that mediate invasion, vascular association and proliferation of glioblastoma cells. Inhibitors of the angiogenin-plexin-B2 axis have therapeutic potential against glioblastoma.

Glycomaterials to Investigate the Functional Role of Aberrant Glycosylation in Glioblastoma

Glioblastoma (GBM) is a stage IV astrocytoma that carries a dismal survival rate of ≈10 months postdiagnosis and treatment. The highly invasive capacity of GBM and its ability to escape therapeutic challenges are key factors contributing to the poor overall survival rate. While current treatments aim to target the cancer cell itself, they fail to consider the significant role that the GBM tumor microenvironment (TME) plays in promoting tumor progression and therapeutic resistance. The GBM tumor glycocalyx and glycan-rich extracellular matrix (ECM), which are important constituents of the TME have received little attention as therapeutic targets. A wide array of aberrantly modified glycans in the GBM TME mediate tumor growth, invasion, therapeutic resistance, and immunosuppression. Here, an overview of the landscape of aberrant glycan modifications in GBM is provided, and the design and utility of 3D glycomaterials are discussed as a tool to evaluate glycan-mediated GBM progression and therapeutic efficacy. The development of alternative strategies to target glycans in the TME can potentially unveil broader mechanisms of restricting tumor growth and enhancing the efficacy of tumor-targeting therapeutics.

CD24, A Review of its Role in Tumor Diagnosis, Progression and Therapy

CD24, is a mucin-like GPI-anchored molecules. By immunohistochemistry, it is widely detected in many solid tumors, such as breast cancers, genital system cancers, digestive system cancers, neural system cancers and so on. The functional roles of CD24 are either fulfilled by combination with ligands or participate in signal transduction, which mediate the initiation and progression of neoplasms. However, the character of CD24 remains to be intriguing because there are still opposite voices about the impact of CD24 on tumors. In preclinical studies, CD24 target therapies, including monoclonal antibodies, target silencing by RNA interference and immunotherapy, have shown us brighten futures on the anti-tumor application. Nevertheless, evidences based on clinical studies are urgently needed. Here, with expectancy to spark new ideas, we summarize the relevant studies about CD24 from a tumor perspective.

Prospects of antibodies targeting CD47 or CD24 in the treatment of glioblastoma

Glioma is a malignant tumor with the highest incidence among all brain tumors (about 46% of intracranial tumors) and is the most common primary intracranial tumor. Among them, glioblastoma (GBM) is highly malignant and is one of the three refractory tumors with the highest mortality rate in the world. The survival time from glioblastoma diagnosis to death is only 14–16 months for patients with standard treatment such as surgery plus radiotherapy and chemotherapy. Due to its high malignancy and poor prognosis, in‐depth studies have been conducted to explore effective therapeutic strategies for glioblastoma. In addition to the conventional surgery, radiotherapy, and chemotherapy, the glioblastoma treatments also include targeted therapy, immunotherapy, and electric field treatment. However, current treatment methods provide limited benefits because of the heterogeneity of glioblastoma and the complexity of the immune microenvironment within a tumor. Therefore, seeking an effective treatment plan is imperative. In particular, developing an active immunotherapy for glioblastoma has become an essential objective in the field. This article reviews the feasibility of CD47/CD24 antibody treatment, either individually or in combination, to target the tumor stem cells and the antitumor immunity in glioblastoma. The potential mechanisms underlying the antitumor effects of CD47/CD24 antibodies are also discussed.

The signal transducer CD24 suppresses the germ cell program and promotes an ectodermal rather than mesodermal cell fate in embryonal carcinomas

Testicular germ cell tumors (GCTs) are stratified into seminomas and nonseminomas. Seminomas share many histological and molecular features with primordial germ cells, whereas the nonseminoma stem cell population—embryonal carcinoma (EC)—is pluripotent and thus able to differentiate into cells of all three germ layers (teratomas). Furthermore, ECs are capable of differentiating into extra‐embryonic lineages (yolk sac tumors, choriocarcinomas). In this study, we deciphered the molecular and (epi)genetic mechanisms regulating expression of CD24, a highly glycosylated signaling molecule upregulated in many cancers. CD24 is overexpressed in ECs compared with other GCT entities and can be associated with an undifferentiated pluripotent cell fate. We demonstrate that CD24 can be transactivated by the pluripotency factor SOX2, which binds in proximity to the CD24 promoter. In GCTs, CD24 expression is controlled by epigenetic mechanisms, that is, histone acetylation, since CD24 can be induced by the application histone deacetylase inhibitors. Vice versa, CD24 expression is downregulated upon inhibition of histone methyltransferases, E3 ubiquitin ligases, or bromodomain (BRD) proteins. Additionally, three‐dimensional (3D) co‐cultivation of EC cells with microenvironmental cells, such as fibroblasts, and endothelial or immune cells, reduced CD24 expression, suggesting that crosstalk with the somatic microenvironment influences CD24 expression. In a CRISPR/Cas9 deficiency model, we demonstrate that CD24 fulfills a bivalent role in differentiation via regulation of homeobox, and phospho‐ and glycoproteins; that is, it is involved in suppressing the germ cell/spermatogenesis program and mesodermal/endodermal differentiation, while poising the cells for ectodermal differentiation. Finally, blocking CD24 by a monoclonal antibody enhanced sensitivity toward cisplatin in EC cells, including cisplatin‐resistant subclones, highlighting CD24 as a putative target in combination with cisplatin.

The Past, Present and Future of Flow Cytometry in Central Nervous System Malignancies

Central nervous system malignancies (CNSMs) are categorized among the most aggressive and deadly types of cancer. The low median survival in patients with CNSMs is partly explained by the objective difficulties of brain surgeries as well as by the acquired chemoresistance of CNSM cells. Flow Cytometry is an analytical technique with the ability to quantify cell phenotype and to categorize cell populations on the basis of their characteristics. In the current review, we summarize the Flow Cytometry methodologies that have been used to study different phenotypic aspects of CNSMs. These include DNA content analysis for the determination of malignancy status and phenotypic characterization, as well as the methodologies used during the development of novel therapeutic agents. We conclude with the historical and current utility of Flow Cytometry in the field, and we propose how we can exploit current and possible future methodologies in the battle against this dreadful type of malignancy.

Amalgamation of PI3K and EZH2 blockade synergistically regulates invasion and angiogenesis: combination therapy for glioblastoma multiforme

Glioblastoma multiforme is known as the primary malignant and most devastating form of tumor in central nervous system of adult population. Amongst all CNS cancers, Glioblastoma multiforme GBM is a rare grade IV astrocytoma and it has the worst prognosis initiated by metastasis to supra-tentorial region of the brain. Current options for the treatment include surgery, radiation therapy and chemotherapy. Substantial information of its pathology and molecular signaling exposed new avenues for generating innovative therapies. In our study, we have undertaken a novel combination approach for GBM treatment. PI3K signaling participates in cancer progression and plays a significant role in metastasis. Here, we are targeting PI3K signaling pathways in glioblastoma along with EZH2, a known transcriptional regulator. We found that targeting transcriptional regulator EZH2 and PI3K affect cellular migration and morphological changes. These changes in signatory activities of cancerous cells led to inhibit its progression in vitro. With further analysis we confirmed the angiogenic inhibition and reduction in stem-ness potential of GBM. Later, cytokine proteome array analysis revealed several participants of metastasis and tumor induced angiogenesis using combination regime. This study provides a significant reduction in GBM progression investigated using Glioblastoma Multiforme U-87 cells with effective combination of pharmacological inhibitors PI-103 and EPZ-6438. This strategy will be further used to combat GBM more innovatively along with the existing therapies.

Haloperidol Induced Cell Cycle Arrest and Apoptosis in Glioblastoma Cells

Although several antipsychotic drugs have been shown to possess anticancer activities, haloperidol, a “first-generation” antipsychotic drug, has not been extensively evaluated for potential antineoplastic properties. The aim of this study was to investigate the antitumoral effects of haloperidol in glioblastoma (GBM) U87, U251 and T98 cell lines, and the effects of combined treatment with temozolomide (TMZ) and/or radiotherapy, using 4 Gy of irradiation. The viability and proliferation of the cells were evaluated with trypan blue exclusion assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis, using the annexin-propidium iodide (PI), and cell cycle, cluster of differentiation (CD) expression and caspase-8 activation were measured using flow cytometry. Treatment with haloperidol significantly reduced cell viability in U87, U251 and T98 GBM cell lines. Haloperidol induced apoptosis in a dose-dependent manner, inhibited cell migration and produced an alteration in the expression of CD24/CD44. The additional effect of haloperidol, combined with temozolomide and radiation therapy, increased tumor cell death. Haloperidol was observed to induce apoptosis and to increase caspase-8 activation. In conclusion, haloperidol may represent an innovative strategy for the treatment of GBM and further studies are warranted in glioma xenograft models and other malignancies.

The Emerging Role of CD24 in Cancer Theranostics-A Novel Target for Fluorescence Image-Guided Surgery in Ovarian Cancer and Beyond

Complete cytoreductive surgery is the cornerstone of the treatment of epithelial ovarian cancer (EOC). The application of fluorescence image-guided surgery (FIGS) allows for the increased intraoperative visualization and delineation of malignant lesions by using fluorescently labeled targeting biomarkers, thereby improving intraoperative guidance. CD24, a small glycophosphatidylinositol-anchored cell surface receptor, is overexpressed in approximately 70% of solid cancers, and has been proposed as a prognostic and therapeutic tumor-specific biomarker for EOC. Recently, preclinical studies have demonstrated the benefit of CD24-targeted contrast agents for non-invasive fluorescence imaging, as well as improved tumor resection by employing CD24-targeted FIGS in orthotopic patient-derived xenograft models of EOC. The successful detection of miniscule metastases denotes CD24 as a promising biomarker for the application of fluorescence-guided surgery in EOC patients. The aim of this review is to present the clinical and preclinically evaluated biomarkers for ovarian cancer FIGS, highlight the strengths of CD24, and propose a future bimodal approach combining CD24-targeted fluorescence imaging with radionuclide detection and targeted therapy.

Identification of CD24 as a potential diagnostic and therapeutic target for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive malignancy of the pleura that is currently incurable due to the lack of an effective early diagnostic method and specific medication. The CDKN2A (p16) and NF2 genes are both frequently mutated in MPM. To understand how these mutations contribute to MPM tumor growth, we generated NF2/p16 double-knockout (DKO) cell clones using human MeT-5A and HOMC-B1 mesothelial cell lines. Cell growth and migration activities were significantly increased in DKO compared with parental cells. cDNA microarray analysis revealed differences in global gene expression profiles between DKO and parental cells. Quantitative PCR and western blot analyses showed upregulation of CD24 concomitant with increased phosphorylation of AKT, p70S6K, and c-Jun in DKO clones. This upregulation was abrogated by exogenous expression of NF2 and p16. CD24 knockdown in DKO cells significantly decreased TGF-β1 expression and increased expression of E-cadherin, an epithelial-mesenchymal transition marker. CD24 was highly expressed in human mesothelioma tissues (28/45 cases, 62%) and associated with the loss of NF2 and p16. Public data analysis revealed a significantly shorter survival time in MPM patients with high CD24 gene expression levels. These results strongly indicate the potential use of CD24 as a prognostic marker as well as a novel diagnostic and therapeutic target for MPM.

CD24 blunts the sensitivity of retinoblastoma to vincristine by modulating autophagy

Retinoblastoma (RB) is the most common childhood malignant intraocular tumor. The clinical efficacy of vincristine (VCR) in the treatment of RB is severely limited by drug resistance. Here, we found that CD24, a GPI-anchored protein, was overexpressed in human RB tissues and RB cell lines, and was associated with the sensitivity of RB cells in response to VCR therapy. We demonstrated that CD24 plays a critical role in impairing RB sensitivity to VCR via regulating autophagy. Mechanistically, CD24 recruits PTEN to the lipid raft domain and regulates the PTEN/AKT/mTORC1 pathway to activate autophagy. Lipid raft localization was essential for CD24 recruitment function. Collectively, our findings revealed a novel role of CD24 in regulating RB sensitivity to VCR and showed that CD24 is a potential target for improving chemotherapeutic sensitivity and RB patient outcomes.

Association of CD44 and CD24 phenotype with lymph node metastasis and survival in triple-negative breast cancer

BACKGROUND

CD44⁺CD24^-/low phenotypes are associated with poor outcome of triple-negative breast cancer (TNBC); however, the role of the CD44⁺CD24^-/low phenotype in lymph node metastasis and survival has not been fully understood in TNBC.

METHODS

A total of 51 TNBC patients were included. CD44 and CD24 expression was determined using immunohistochemistry by which CD44 and CD24 were double-immunostained. Overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method.

RESULTS

The proportion of the CD44⁺CD24^-/low phenotype was 33.3% in TNBC specimens without lymph node metastases and 69.0% in those with lymph node metastases. In addition, the CD44⁺CD24^-/low phenotype correlated significantly with tumor size, histologic classification, TNM stage, and lymph node metastasis (P < 0.05). The CD44⁺CD24^-/low phenotype was detected in 69.0% of TNBC patients with lymph node metastases, and 51.7% of TNBC patients without lymph node metastases. In TNBC patients without lymph node metastases, the median DFS and OS were 18.2 and 28 months in cases with a CD44⁺CD24^-/low phenotype and 26.5 and 42.5 months in those without a CD44⁺CD24^-/low phenotype (P < 0.05), and in TNBC patients with lymph node metastases, the median DFS and OS were 17.2 and 25.7 months in cases with a CD44⁺CD24^-/low phenotype and 24.5 and 39.3 months in those without a CD44⁺CD24^-/low phenotype, respectively (P < 0.05).

CONCLUSIONS

CD44 and CD24 are independent prognostic markers for patients with TNBC. The CD44⁺CD24^-/low phenotype correlates with more aggressive clinicopathologic features and is strongly associated with poor prognosis in patients with TNBC.

CD24 and CK4 are upregulated by SIM2, and are predictive biomarkers for chemoradiotherapy and surgery in esophageal cancer

Definitive chemoradiotherapy (CRT) is a less invasive therapy compared with surgery for some types of cancer; however, the 5‑year survival rate of patients with stages II‑III esophageal squamous cell carcinoma (ESCC) is only 37%. Therefore, prediction of CRT responders is necessary. Unfortunately, no definitive biomarker exists that is useful to predict survival outcome following CRT. From our previous microarray study, CD24 and keratin 4 (KRT4), which encodes cytokeratin 4 (CK4), were overexpressed in the favorable prognostic epithelial subtype with SIM bHLH transcription factor 2 (SIM2) expression. This study investigated the association between their mRNA and protein expression levels, and clinicopathological characteristics, and also investigated the functions of CD24 in SIM2‑mediated tumor differentiation and CRT sensitivity. High CD24 and KRT4 mRNA expression was associated with a favorable prognosis following CRT. Multivariate analyses revealed that high CD24 and CK4 protein expression, as determined by immunohistochemistry, and differentiated type were independent factors for predicting a favorable prognosis in response to CRT. Notably, in cases with low CD24 or CK4, surgery was suggested to be a good therapeutic modality compared with CRT. CD24 and KRT4 were expressed preferentially in differentiated layers of the normal esophageal mucosa, and their mRNA expression in 3D cultured ESCC cells was induced by SIM2 transfection, thus suggesting that CD24 and KRT4 were downstream differentiation markers of SIM2. Furthermore, CD24 small interfering RNA increased the mRNA expression levels of superoxide dismutase 2 and enhanced H2O2 resistance, thus indicating the involvement of CD24 in the radiosensitivity of patients with ESCC; however, it had no effect on cisplatin sensitivity. In conclusion, the two markers CD24 and CK4 may be considered predictive biomarkers for definitive CRT.

Deglucohellebrin: A Potent Agent for Glioblastoma Treatment

BACKGROUND

Glioblastoma is the most common primary brain tumor in adults with a dismal prognosis. To date, several anticancer agents have been isolated from plants. Helleborus odorus subsp. Cyclophyllus is an endemic plant of the Balcan flora. Herewith, we investigated for the first time, the anti-glioma effect of deglucohellebrin (DGH) extracted from the roots of Helleborus.

METHODS

We investigated the effect of DGH in U251MG, T98G and U87G glioblastoma cell lines. We selected the T98G cells because of their inherent temozolomide resistance.

RESULTS

The IC50 value of reduced viability for DGH was 7x10-5M in U251MG cells, 5x10-5M for the T98G cells and 4x10-5M in U87G cells during 72h treatment. DGH induced G2/M cell cycle arrest, caspace-8 activation and significant mitochondrial membrane depolarization, suggesting the activation of the intrinsic, mitochondrial- dependent apoptotic pathway. DGH and temozolomide induced changes in CDs' expression in U251MG and T98G cells. In zebrafish, DGH did not induce toxicity or behavioral alterations.

CONCLUSION

The present study is the first to determine the anti-glioma activity of DGH. DGH may be a potent agent for glioblastoma treatment and further studies are needed.

Reduced DAXX Expression Is Associated with Reduced CD24 Expression in Colorectal Cancer

The presence of an activating mutation of the Wnt/β-catenin signaling pathway is found in ~90% of colorectal cancer (CRC) cases. Death domain-associated protein (DAXX), a nuclear protein, interacts with β-catenin in CRC cells. We investigated DAXX expression in 106 matched sample pairs of CRC and adjacent normal tissue by Western blotting. This study evaluated DAXX expression and its clinical implications in CRC. The results revealed that DAXX expression was significantly lower in the patients with the positive serum carcinoembryonic antigen (CEA) screening results compared to the patients with negative CEA screening levels (p < 0.001). It has been reported that CD24 is a Wnt target in CRC cells. Here, we further revealed that DAXX expression was significantly correlated with CD24 expression (rho = 0.360, p < 0.001) in 106 patients. Consistent with this, in the CEA-positive subgroup, of which the carcinomas expressed DAXX at low levels, they were significantly correlated with CD24 expression (rho = 0.461, p < 0.005). Therefore, reduced DAXX expression is associated with reduced CD24 expression in CRC. Notably, in the Hct116 cells, DAXX knockdown using short-hairpin RNA against DAXX (shDAXX) not only caused significant cell proliferation, but also promoted metastasis. The DAXX-knockdown cells also demonstrated significantly decreased CD24 expression, however the intracellular localization of CD24 did not change. Thus, DAXX might be considered as a potential regulator of CD24 or β-catenin expression, which might be correlated with proliferative and metastatic potential of CRC.

Anti-CD24 bio Modified PEGylated Gold Nanoparticles as Targeted Computed Tomography Contrast Agent

Purpose: Molecular imaging is one of the import methods for recognition of cancer at the early stage in order to enhance the capacity of remedy. This study was aimed to introduce a new contrast agent that was targeted with CD24 so as to improve the CT scan detection of cancer cells with higher CD24 expression. Methods: The surface modifications of gold nanoparticles (Au-NPs) were done with long PEG (HS-PEG-CH3O) and short PEG (HS-PEG-COOH) chains to enhance their stability and capacity for immobilization of different antibodies. MTT assay was carried out to assess the biocompatibility of the NPs. The obtained contrast agent was implemented in the targeted CT imaging based on in vitro and in vivo studies of breast cancer. Results: The results revealed that the attached CD24 to the cell surface of PEGylated Au-NPs could enhance significantly the cells CT number (40.45 HU in 4T1, while it was 16.61 HU in CT26) It was shown that the attenuation coefficient of the molecularly targeted cells was more than 2 times excessive than the control groups. Further, the tumor region in model of xenograft tumor has higher density compare to the omnipaque groups, 60 min after injection (45 Hu vs.81 Hu). These results showed that the nanoparticles stayed in tumor region for longer time. Conclusion: It is predicted that the synthesized nanoparticle can be used as computed tomography contrast agent. Also, it can be used to identify the tumor cells with higher expression of CD24 at the early stages more efficiently compare to the other routine methods.

Correlation of CD133 and Oct-4 expression with clinicopathological and demographic parameters in oral squamous cell carcinoma patients

OBJECTIVE

Squamous cell carcinoma of oral cavity is one of the most common cancers of Indian subcontinent with the 5-year survival rate of 50% despite the recent advances in the treatment. The aim of the present study was to study cancer stem cell markers CD133 and Oct-4 in oral squamous cell carcinoma (OSCC) patients and their correlation with clinicopathological variables.

MATERIALS AND METHODS

This was a prospective study which included 50 cases of histopathologically proven squamous cell carcinoma of oral cavity. Expression of CD133 and Oct-4 was evaluated by immunohistochemistry (IHC) and their expression was correlated with various clinicopathological and demographic parameters.

RESULTS

CD133 expression was seen in 20.6% cases of clinical Stage I-II and in 79.4% of clinical stage of III-IV OSCC patients, the difference being statistically significant with the P = 0.048. There was no statistically significant association between CD133 expression and any other clinicopathological or demographic variable. Oct-4 was expressed only in one case.

CONCLUSIONS

CD133 expression was significantly seen higher in Stage III-IV tumors, the stem cells may be responsible for the aggressiveness of the OSCCs and these stem cells can be potential prognostic markers and targets for the future targeted therapy.

CD24 and Nanog expression in Stem Cells in Glioblastoma: Correlation with Response to Chemoradiation and Overall Survival

Background and aim: Glioblastoma (GBM) is one of the most common and aggressive brain tumors with a median survival of 12-14 months. The aim of present study was to evaluate the gene expression profile of stem cell markers Nanog and CD24 in GBM and to determine its relationship to outcome in terms of treatment response and overall survival. Material and methods: This was a retrospective as well as retrospective study which included 51 histologically confirmed cases of GBM. Expression of CD24, and Nanog was evaluated by RT-PCR. Control tissue included debrided brain tissue from open head injury cases. All cases of GBM underwent total surgical resection and subsequently chemotherapy. Immediate treatment response was evaluated at 3 months using Response Evaluation Criteria In Solid Tumors (RECIST) guidelines and overall survival was measured at 36 months. Result: As compared to control gene, expression of CD24 and Nanog was seen to be unregulated to 24.5% and 31.7% respectively. However, the difference in mean expression of cases and controls was not statistically significant. Correlation between expressions of these two markers was also not statistically significant. On univariate cox regression analysis, cases with >2 fold expression of CD24 and Nanog had significantly poor survival as compared to those with <2 fold expression. On multivariate analysis > 2 fold CD24 expression had a statistically significant correlation with poor survival. Conclusion: An overexpression of CD24 by more than two fold was associated with poor overall survival in GBM. Poor survival may be related to increased “stemness” of tumour cells. Targeted therapy inclusive of drugs targeting stem cells directly or indirectly may be a promising therapeutic option.

CD24 expression is a marker for predicting clinical outcome and regulates the epithelial-mesenchymal transition in ovarian cancer via both the Akt and ERK pathways

The degree of peritoneal dissemination and chemotherapy-resistant tumors is related to the prognosis in patients with advanced-stage ovarian cancer. The epithelial-mesenchymal-transition (EMT) is a multifaceted pathological program that endows cancer cells with the ability to invade and disseminate. CD24 is frequently overexpressed in various human cancers and is correlated with a poor prognosis. We herein examined the functions of CD24 in human ovarian cancer cell lines and evaluated how it contributes to the molecular mechanism underlying the regeneration of cancer stem-like cells (CSCs) through the EMT mechanism in ovarian carcinoma. We demonstrated that CD24 was expressed in 70.1% of primary ovarian carcinoma tissues, which were obtained from 174 patients, and that the expression of CD24 was an independent predictor of survival in patients with ovarian cancer. The expression of CD24 has been found to be correlated with the FIGO stage, presence of peritoneal and lymph node metastasis. CD24 induces the EMT phenomenon, which is involved in cell invasion, the highly proliferative phenotype, colony formation and which is associated with cisplatin resistance and the properties of CSCs, via the activation of PI3K/Akt, NF-κB and ERK in Caov-3 cisplatin-resistant cell lines. CD24-positive ovarian carcinomas have been shown to have a greater potential for intra-abdominal tumor cell dissemination in in vivo models. Our findings suggest that CD24 induced the EMT phenomenon in ovarian cancer, and that CD24 amplified cell growth-related intracellular signaling via the PI3K/Akt and MAPK pathways by affecting the EMT signal pathways. We believe that CD24 is a key molecule of metastatic progression in the EMT phenomenon and a promising therapeutic target for advanced ovarian cancer.

N-(p-coumaroyl) serotonin inhibits glioblastoma cells growth through triggering S-phase arrest and apoptosis

Glioblastoma is the most common and most malignant primary brain tumor with a median survival of 15 months. N-(p-coumaroyl) serotonin (CS) is an indole alkaloid with antioxidant, cardioprotective effects after ischemia and antitumor activity. In the present study we sought to determine whether could exert cytotoxic and cytostatic effects in glioma cells in vitro. CS was tested for toxicity in zebrafish. We investigated the effect of CS in U251MG and T98G glioblastoma cell lines. Viability and proliferation of the cells were examined with trypan blue exclusion assay and the xCELLigence system. Cell cycle, activation of caspase-8, mitochondrial membrane potential and CD24/CD44/CD56/CD15/CD71 expression were tested with flow cytometry. Treatment with CS significantly reduced cell viability in both cell lines tested. Induction of cell death and cell cycle arrest at G2/M and S-phase was confirmed with flow cytometry in both cell lines. CS produced significant higher activity of caspase-8 compared to control. After treatment with CS there was a dose-dependent increase in CD15 and CD71 expression, whereas there was no change in CD24/CD44/CD56 expression in both cell lines. The zebrafish mortality on the fifth post fertilization day was zero for even 1 mM of CS concentration. The treatment of glioblastoma cell lines with CS may represent a novel strategy for targeting glioblastoma. Further studies are obviously needed to elucidate the complete mechanism of its antitumor activity.

Analysis of Chemopredictive Assay for Targeting Cancer Stem Cells in Glioblastoma Patients

INTRODUCTION

The prognosis of glioblastoma (GBM) treated with standard-of-care maximal surgical resection and concurrent adjuvant temozolomide (TMZ)/radiotherapy remains very poor (less than 15 months). GBMs have been found to contain a small population of cancer stem cells (CSCs) that contribute to tumor propagation, maintenance, and treatment resistance. The highly invasive nature of high-grade gliomas and their inherent resistance to therapy lead to very high rates of recurrence. For these reasons, not all patients with similar diagnoses respond to the same chemotherapy, schedule, or dose. Administration of ineffective anticancer therapy is not only costly but more importantly burdens the patient with unnecessary toxicity and selects for the development of resistant cancer cell clones. We have developed a drug response assay (ChemoID) that identifies the most effective chemotherapy against CSCs and bulk of tumor cells from of a panel of potential treatments, offering great promise for individualized cancer management. Providing the treating physician with drug response information on a panel of approved drugs will aid in personalized therapy selections of the most effective chemotherapy for individual patients, thereby improving outcomes. A prospective study was conducted evaluating the use of the ChemoID drug response assay in GBM patients treated with standard of care.

METHODS

Forty-one GBM patients (mean age 54 years, 59% male), all eligible for a surgical biopsy, were enrolled in an Institutional Review Board-approved protocol, and fresh tissue samples were collected for drug sensitivity testing. Patients were all treated with standard-of-care TMZ plus radiation with or without maximal surgery, depending on the status of the disease. Patients were prospectively monitored for tumor response, time to recurrence, progression-free survival (PFS), and overall survival (OS). Odds ratio (OR) associations of 12-month recurrence, PFS, and OS outcomes were estimated for CSC, bulk tumor, and combined assay responses for the standard-of-care TMZ treatment; sensitivities/specificities, areas under the curve (AUCs), and risk reclassification components were examined.

RESULTS

Median follow-up was 8 months (range 3-49 months). For every 5% increase in in vitro CSC cell kill by TMZ, 12-month patient response (nonrecurrence of cancer) increased two-fold, OR=2.2 (P=.016). Similar but somewhat less supported associations with the bulk tumor test were seen, OR=2.75 (P=.07) for each 5% bulk tumor cell kill by TMZ. Combining CSC and bulk tumor assay results in a single model yielded a statistically supported CSC association, OR=2.36 (P=.036), but a much attenuated remaining bulk tumor association, OR=1.46 (P=.472). AUCs and [sensitivity/specificity] at optimal outpoints (>40% CSC cell kill and >55% bulk tumor cell kill) were AUC=0.989 [sensitivity=100/specificity=97], 0.972 [100/89], and 0.989 [100/97] for the CSC only, bulk tumor only, and combined models, respectively. Risk categorization of patients was improved by 11% when using the CSC test in conjunction with the bulk test (risk reclassification nonevent net reclassification improvement [NRI] and overall NRI=0.111, P=.030). Median recurrence time was 20 months for patients with a positive (>40% cell kill) CSC test versus only 3 months for those with a negative CSC test, whereas median recurrence time was 13 months versus 4 months for patients with a positive (>55% cell kill) bulk test versus negative. Similar favorable results for the CSC test were observed for PFS and OS outcomes. Panel results across 14 potential other treatments indicated that 34/41 (83%) potentially more optimal alternative therapies may have been chosen using CSC results, whereas 27/41 (66%) alternative therapies may have been chosen using bulk tumor results.

CONCLUSIONS

The ChemoID CSC drug response assay has the potential to increase the accuracy of bulk tumor assays to help guide individualized chemotherapy choices. GBM cancer recurrence may occur quickly if the CSC test has a low in vitro cell kill rate even if the bulk tumor test cell kill rate is high.

The CD24 surface antigen in neural development and disease

A cell's surface molecular signature enables its reciprocal interactions with the associated microenvironments in development, tissue homeostasis and pathological processes. The CD24 surface antigen (heat-stable antigen, nectadrin; small cell lung cancer antigen cluster-4) represents a prime example of a neural surface molecule that has long been known, but whose diverse molecular functions in intercellular communication we have only begun to unravel. Here, we briefly summarize the molecular fundamentals of CD24 structure and provide a comprehensive review of CD24 expression and functional studies in mammalian neural developmental systems and disease models (rodent, human). Striving for an integrated view of the intracellular signaling processes involved, we discuss the most pertinent routes of CD24-mediated signaling pathways and functional networks in neurobiology (neural migration, neurite extension, neurogenesis) and pathology (tumorigenesis, multiple sclerosis).

Gene Expression Profiling of Prostate Cancer–Associated Genes Identifies Fibromodulin as Potential Novel Biomarker for Prostate Cancer

Background

The aim of this study was to evaluate the gene expression profiles of a set of prostate cancer–associated genes in prostate cancer cell lines, to determine their association with different cancer phenotypes and identify potential novel biomarkers for this disease.

Methods

Quantitative real-time PCR was used to determine the expression profiles of 21 prostate cancer–associated genes in the human prostate cancer cell lines PC-3 and LNCaP, using the nontumorigenic cell line PWR-1E as control cell line. Genes evaluated were ESM-1, SERPINE2, CLU, BGN, A2M, PENK, FMOD, CD81, DCN, TSPAN8, KBTBD10, F2RL1, TMSB4X, SNCG, CXXC5, FOXQ1, PDPN, SPN, CAV1, CD24 and KLK3. A potential biomarker from this set of genes, the FMOD gene, encoding the small leucine-rich proteoglycan fibromodulin, was selected for further evaluation in clinical samples from patients diagnosed with benign or malignant prostatic disease.

Results

Several of the evaluated genes showed significantly altered expression in the prostate cancer cell lines, compared with nontumorigenic PWR-1E cells. Further evaluation of FMOD transcript in prostate clinical samples from patients diagnosed with benign or malignant prostatic disease identified a significant difference in the expression levels of this proteoglycan between benign and malignant tissue (p<0.05).

Conclusions

A number of gene transcripts were differentially expressed by the cell lines assayed. Among them, FMOD was further evaluated in clinical samples and was found to be differentially expressed between benign and prostate cancer tissue. Further validation of FMOD transcript in a larger population is required to ascertain its usefulness as biomarker for prostate cancer.

CD24 promotes HCC progression via triggering Notch-related EMT and modulation of tumor microenvironment

CD24 is known as a cell surface molecule in hematopoiesis and also described as a diagnostic marker for tumors. Previous studies suggested the important role of CD24 in hepatocellular carcinoma (HCC) pathogenesis. However, precise functions of CD24 in HCC are still unknown. Here, we found that CD24 is highly expressed in HCC both in mRNA and protein levels. Further, the epithelial-mesenchymal transition (EMT) and Notch1 signaling activations mediated by CD24 were elucidated as potential mechanisms of HCC promotion in Hepa1-6/Hepa1-6-CD24 cell models. Additionally, possible systemic immune reaction was explored through immune cells and Hepa1-6/Hepa1-6-CD24 cell co-culture. We demonstrated that the EMT process of HCC cell was effectively induced by CD24; also, the tumor immune microenvironment was changed by facilitating Notch-related EMT in vivo. These results reveal the underlying link between the HCC processes mediated by CD24. Moreover, as a clear tumor promoter, CD24 is considered a potential new target for HCC treatment.

CD24 expression as a marker for predicting clinical outcome and invasive activity in uterine cervical cancer

CD24, a small heavily glycosylated mucin-like glycosylphosphatidylinositol-anchored cell surface protein, plays an important role in the carcinogenesis of various human malignancies. However, its function in cervical cancer remains unclear. The aim of the present study was to evaluate the expression of CD24 clinicopathologically and to analyze its functional behavior biologically in cervical cancer. A total of 117 uterine cervical cancer tumors were immunohistochemically analyzed using a CD24 monoclonal antibody on paraffin blocks. We also examined whether CD24 enhanced the invasive activity or the Akt, ERK, NF-κB and MMP activity in a uterine cervical cancer cell line (CaSki) by a western blot analysis. The patients with enhanced CD24 expression had a higher rate of advanced clinical stage (50 vs. 16.5%, p<0.01), lymph node metastasis (34.6 vs. 14.3%) and lymphovascular involvement (65.4 vs. 20.4%, p=0.01), and a poor overall and disease-free survival (5-year survival rate: 62 vs. 86%, p=0.03). CD24 overexpression in CaSki cells resulted in activation of Cell Signaling proteins, including Akt, ERK, NF-κB and MMP-9. An invasion assay showed that CD24 overexpression in CaSki cells led to increased invasion ability. The CD24 overexpression also increased mRNA expression of Slug but not Snail. Moreover, the CD24 overexpression also decreased expression of E-cadherin and increased N-cadherin protein levels. Increased expression of CD24 may be associated with tumor progression and prognosis in patients with uterine cervical cancer. CD24 expression may therefore be used not only as a prognostic marker in uterine cervical cancer, but also as a target for the development of new therapeutic approaches.

Intracellular CD24 disrupts the ARF-NPM interaction and enables mutational and viral oncogene-mediated p53 inactivation

CD24 is overexpressed in nearly 70% human cancers, whereas TP53 is the most frequently mutated tumour-suppressor gene that functions in a context-dependent manner. Here we show that both targeted mutation and short hairpin RNA (shRNA) silencing of CD24 retard the growth, progression and metastasis of prostate cancer. CD24 competitively inhibits ARF binding to NPM, resulting in decreased ARF, increase MDM2 and decrease levels of p53 and the p53 target p21/CDKN1A. CD24 silencing prevents functional inactivation of p53 by both somatic mutation and viral oncogenes, including the SV40 large T antigen and human papilloma virus 16 E6-antigen. In support of the functional interaction between CD24 and p53, in silico analyses reveal that TP53 mutates at a higher rate among glioma and prostate cancer samples with higher CD24 mRNA levels. These data provide a general mechanism for functional inactivation of ARF and reveal an important cellular context for genetic and viral inactivation of TP53.

P53 is a tumour suppressor that is frequently mutated or downregulated in cancer. Here, Wang et al. show that CD24, a molecule frequently overexpressed in cancer, promotes p53 degradation by disrupting a regulatory ARF–MDM2 interaction, and silencing CD24 prevents the downregulation of p53.

Identification of novel tumor-associated cell surface sialoglycoproteins in human glioblastoma tumors using quantitative proteomics

Glioblastoma multiform (GBM) remains clinical indication with significant “unmet medical need”. Innovative new therapy to eliminate residual tumor cells and prevent tumor recurrences is critically needed for this deadly disease. A major challenge of GBM research has been the identification of novel molecular therapeutic targets and accurate diagnostic/prognostic biomarkers. Many of the current clinical therapeutic targets of immunotoxins and ligand-directed toxins for high-grade glioma (HGG) cells are surface sialylated glycoproteins. Therefore, methods that systematically and quantitatively analyze cell surface sialoglycoproteins in human clinical tumor samples would be useful for the identification of potential diagnostic markers and therapeutic targets for malignant gliomas. In this study, we used the bioorthogonal chemical reporter strategy (BOCR) in combination with label-free quantitative mass spectrometry (LFQ-MS) to characterize and accurately quantify the individual cell surface sialoproteome in human GBM tissues, in fetal, adult human astrocytes, and in human neural progenitor cells (NPCs). We identified and quantified a total of 843 proteins, including 801 glycoproteins. Among the 843 proteins, 606 (72%) are known cell surface or secreted glycoproteins, including 156 CD-antigens, all major classes of cell surface receptor proteins, transporters, and adhesion proteins. Our findings identified several known as well as new cell surface antigens whose expression is predominantly restricted to human GBM tumors as confirmed by microarray transcription profiling, quantitative RT-PCR and immunohistochemical staining. This report presents the comprehensive identification of new biomarkers and therapeutic targets for the treatment of malignant gliomas using quantitative sialoglycoproteomics with clinically relevant, patient derived primary glioma cells.

Genomic analyses reveal broad impact of miR-137 on genes associated with malignant transformation and neuronal differentiation in glioblastoma cells

miR-137 plays critical roles in the nervous system and tumor development; an increase in its expression is required for neuronal differentiation while its reduction is implicated in gliomagenesis. To evaluate the potential of miR-137 in glioblastoma therapy, we conducted genome-wide target mapping in glioblastoma cells by measuring the level of association between PABP and mRNAs in cells transfected with miR-137 mimics vs. controls via RIPSeq. Impact on mRNA levels was also measured by RNASeq. By combining the results of both experimental approaches, 1468 genes were found to be negatively impacted by miR-137--among them, 595 (40%) contain miR-137 predicted sites. The most relevant targets include oncogenic proteins and key players in neurogenesis like c-KIT, YBX1, AKT2, CDC42, CDK6 and TGFβ2. Interestingly, we observed that several identified miR-137 targets are also predicted to be regulated by miR-124, miR-128 and miR-7, which are equally implicated in neuronal differentiation and gliomagenesis. We suggest that the concomitant increase of these four miRNAs in neuronal stem cells or their repression in tumor cells could produce a robust regulatory effect with major consequences to neuronal differentiation and tumorigenesis.

Amelioration of cancer stem cells in macrophage colony stimulating factor-expressing U87MG-human glioblastoma upon 5-fluorouracil therapy

Macrophage colony stimulating factor (MCSF) regulates growth, proliferation and differentiation of haematopoietic cell lineages. Many cancers are known to secrete high level of MCSF, which recruit macrophages into the tumour micro-environment, supporting tumour growth. Herein, we report the cloning of MCSF and subsequent generation of U87MG expressing MCSF stable cell line (U87-MCSF). Cytotoxicity of anti-cancer drug 5-fluorouracil (5-FU) was evaluated on both U87MG and U87-MCSF cells. Interestingly, the proliferation of U87-MCSF cells was less (p<0.001) than that of U87MG cells alone, after treatment with 5-FU. Significant decrease in expression levels of cyclin E and A2 quantified by real time PCR analysis corroborated the reduced proliferation of 5-FU treated U87-MCSF cells. However, JC-1 staining did not reveal any apoptosis upon 5-FU treatment. Notch-1 upregulation induced a possible epithelial-mesenchymal transition in U87-MCSF cells, which accounted for an increase in the proportion of CD24^high/CD44^less cancer stem cells in U87-MCSF cells after 5-FU treatment. The elevated resistance of U87-MCSF cells towards 5-FU was due to the increase in the expressions (10.2 and 6 fold) of ABCB1 and mdm2, respectively. Furthermore, increase in expressions of ABCG1, mdm2 and CD24 was also observed in U87MG cells after prolonged incubation with 5-FU. Our studies provided mechanistic insights into drug resistance of U87MG cells and also described the pivotal role played by MCSF in augmenting the resistance of U87MG cells to 5-FU.

CD24 induces the invasion of cholangiocarcinoma cells by upregulating CXCR4 and increasing the phosphorylation of ERK1/2

Cholangiocarcinoma is a malignant biliary tract tumor with an extremely poor prognosis. CD24 expression has been linked to the aggressiveness of cholangiocarcinoma cells and the adverse prognosis of cholangiocarcinoma patients. In the present study, the underlying mechanism of aggressive CD24⁺ cholangiocarcinoma cell behavior was elucidated. The magnetic-activated cell sorting system was used to isolate CD24⁺ and CD24^- cell populations from RMCCA1 cholangiocarcinoma cells. Using a human tumor metastasis PCR array, it was observed that numerous tumor-associated genes were upregulated in the CD24⁺ cells, including CXC chemokine receptor type 4 (CXCR4). In addition, an intracellular signaling array demonstrated the activation of extracellular signal-regulated kinase (ERK)1/2, which is downstream of the CXCR4 signaling cascade, in the CD24⁺ cells. Inhibition of CXCR4 or ERK1/2 significantly inhibited the motility and invasiveness of the CD24⁺ cells. The present study indicates that CXCR4 and ERK1/2 are induced by CD24 and that these proteins are associated with cholangiocarcinoma cell invasion.

CD44/CD24 as potential prognostic markers in node-positive invasive ductal breast cancer patients treated with adjuvant chemotherapy

The hypothesis on cancer stem cells assumes the existence of small subpopulation of cells that possess the ability to undergo self-renewal and can give rise to the diversity of differentiated cells that form the tumour. It has been accepted that CD44(+)/CD24(-/low) phenotype is one of the features characterizing breast cancer stem cells. The aim of our study was to assess (1) prognostic significance of CD44/CD24 expression as well as (2) a relation between the above-mentioned phenotype and breast cancer subtypes [based on estrogen (ER), progesterone receptors, human epidermal growth factor receptor 2 and Ki67 status] and expression of selected markers such as fascin, laminin-5 gamma-2 chain, cytokeratin (CK) 5/6 and 8/18, epidermal growth factor receptor (EGFR), smooth muscle actin, P-cadherin and lymphocytic infiltration in invasive ductal breast cancer patients (T ≥ 1, N ≥ 1, M0), who underwent mastectomy followed by chemotherapy (with taxanes and/or anthracyclines) or/and hormonotherapy. We noted that most cancers with CD44-/CD24- and CD44-/CD24+ phenotype were ER positive. The majority of CD44-/CD24-, CD44-/CD24+ and CD44+/CD24- tumours were characterized by CK5/6 and EGFR negativity. In univariate analysis we demonstrated that patients with pN1/pN2 and with CD44 +/CD24- carcinomas had significantly lower risk of progression or cancer-related death than those with pN3 or tumours characterised by other CD44/CD24 expression patterns. We also found 100 % DFS in 12 patients with CD44+/CD24-/CK5/6+/ER- phenotype. Other analysed parameters were insignificant. We conclude that tumours with immunophenotypes: CD44+/CD24- and CD44+/CD24-/CK5/6+/ER- might be more sensitive for chemotherapy based on taxanes and/or anthracyclines.

Transcriptional differences between normal and glioma-derived glial progenitor cells identify a core set of dysregulated genes

Glial progenitor cells (GPCs) are a potential source of malignant gliomas. We used A2B5-based sorting to extract tumorigenic GPCs from human gliomas spanning World Health Organization grades II-IV. Messenger RNA profiling identified a cohort of genes that distinguished A2B5+ glioma tumor progenitor cells (TPCs) from A2B5+ GPCs isolated from normal white matter. A core set of genes and pathways was substantially dysregulated in A2B5+ TPCs, which included the transcription factor SIX1 and its principal cofactors, EYA1 and DACH2. Small hairpin RNAi silencing of SIX1 inhibited the expansion of glioma TPCs in vitro and in vivo, suggesting a critical and unrecognized role of the SIX1-EYA1-DACH2 system in glioma genesis or progression. By comparing the expression patterns of glioma TPCs with those of normal GPCs, we have identified a discrete set of pathways by which glial tumorigenesis may be better understood and more specifically targeted.

Increased expression of CD24 is associated with tumor progression and prognosis in patients suffering osteosarcoma

OBJECTIVE

As a small heavily glycosylated mucin-like glycosyl-phosphatidylinositol-anchored cell surface protein, CD24 plays an important role in carcinogenesis of various human malignancies. However, its involvement in osteosarcoma is still unclear. The aim of this study was to investigate the expression pattern and the clinical significance of CD24 in human osteosarcoma.

METHODS

CD24 mRNA and protein expression levels were, respectively, detected by RT-PCR and Western blot assays using 30 pairs of osteosarcoma and noncancerous bone tissues. Then, immunohistochemistry was performed to analyze the association of CD24 expression in 166 osteosarcoma tissues with clinicopathological factors or survival of patients.

RESULTS

CD24 expression at mRNA and protein levels were both significantly higher in osteosarcoma tissues than those in corresponding noncancerous bone tissues (both P < 0.001). In addition, CD24 protein was positively expressed in 129 of 166 (77.7 %) osteosarcoma specimens with a cytoplasmic and membraneous staining, and also increased in the osteosarcoma specimens with advanced clinical stage (P = 0.01) and positive distant metastasis (P = 0.005). The univariate and multivariate analyses showed that osteosarcoma patients with high CD24 expression had poorer overall and disease-free survival, and high CD24 expression was an independent prognostic factor for both overall and disease-free survival.

CONCLUSION

The aforementioned findings offer convincing evidence for the first time that the increased expression of CD24 is correlated with tumor aggressiveness and tumor metastasis of osteosarcoma, and this molecule is an independent prognostic marker for osteosarcoma patients.