Normal Human Brain Cells Research Articles

Differential Effects of Extracellular Vesicles from Two Different Glioblastomas on Normal Human Brain Cells

Background/Objectives: Glioblastomas (GBMs) are dreadful brain tumors with abysmal survival outcomes. GBM extracellular vesicles (EVs) dramatically affect normal brain cells (largely astrocytes) constituting the tumor microenvironment (TME). We asked if EVs from different GBM patient-derived spheroid lines would differentially alter recipient brain cell phenotypes. This turned out to be the case, with the net outcome of treatment with GBM EVs nonetheless converging on increased tumorigenicity. Methods: GBM spheroids and brain slices were derived from neurosurgical patient tissues following informed consent. Astrocytes were commercially obtained. EVs were isolated from conditioned culture media by ultrafiltration, concentration, and ultracentrifugation. EVs were characterized by nanoparticle tracking analysis, electron microscopy, biochemical markers, and proteomics. Astrocytes/brain tissues were treated with GBM EVs before downstream analyses. Results: EVs from different GBMs induced brain cells to alter secretomes with pro-inflammatory or TME-modifying (proteolytic) effects. Astrocyte responses ranged from anti-viral gene/protein expression and cytokine release to altered extracellular signal-regulated protein kinase (ERK1/2) signaling pathways, and conditioned media from EV-treated cells increased GBM cell proliferation. Conclusions: Astrocytes/brain slices treated with different GBM EVs underwent non-identical changes in various omics readouts and other assays, indicating “personalized” tumor-specific GBM EV effects on the TME. This raises concern regarding reliance on “model” systems as a sole basis for translational direction. Nonetheless, net downstream impacts from differential cellular and TME effects still led to increased tumorigenic capacities for the different GBMs.

Metabolism changes caused by glucose in normal and cancer human brain cell lines by Raman imaging and chemometric methods

Glucose is the main source of energy for the human brain. This paper presents a non-invasive technique to study metabolic changes caused by glucose in human brain cell lines. In this paper we present the spectroscopic characterization of human normal brain (NHA; astrocytes) and human cancer brain (CRL-1718; astrocytoma and U-87 MG; glioblastoma) control cell lines and cell lines upon supplementation with glucose. Based on Raman techniques we have identified biomarkers that can monitor metabolic changes in lipid droplets, mitochondria and nucleus caused by glucose. We have studied the vibrations at 750 cm−1, 1444 cm−1, 1584 cm−1 and 1656 cm−1 as a function of malignancy grade. We have compared the concentration of cytochrome, lipids and proteins in the grade of cancer aggressiveness in normal and cancer human brain cell lines. Chemometric analysis has shown that control normal, control cancer brain cell lines and normal and cancer cell lines after supplementation with glucose can be distinguished based on their unique vibrational properties. PLSDA (Partial Least Squares Discriminant Analysis) and ANOVA tests have confirmed the main role of cytochromes, proteins and lipids in differentiation of control human brain cells and cells upon supplementation with glucose. We have shown that Raman techniques combined with chemometric analysis provide additional insight to monitor the biology of astrocytes, astrocytoma and glioblastoma after glucose supplementation.

Potential Benefits of Dietary Plant Compounds on Normal and Tumor Brain Cells in Humans: In Silico and In Vitro Approaches.

Neuroblastoma can be accessed with compounds of larger sizes and wider polarities, which do not usually cross the blood-brain barrier. Clinical data indicate cases of spontaneous regression of neuroblastoma, suggesting a reversible point in the course of cell brain tumorigenesis. Dual specificity tyrosine-phosphorylation-regulated kinase2 (DYRK2) is a major molecular target in tumorigenesis, while curcumin was revealed to be a strong inhibitor of DYRK2 (PBD ID: 5ZTN). Methods: in silico studies by CLC Drug Discovery Workbench (CLC) and Molegro Virtual Docker (MVD) Software on 20 vegetal compounds from the human diet tested on 5ZTN against the native ligand curcumin, in comparison with anemonin. In vitro studies were conducted on two ethanolic extracts from Anemone nemorosa tested on normal and tumor human brain cell lines NHA and U87, compared with four phenolic acids (caffeic, ferulic, gentisic, and para-aminobenzoic/PABA). Conclusions: in silico studies revealed five dietary compounds (verbascoside, lariciresinol, pinoresinol, medioresinol, matairesinol) acting as stronger inhibitors of 5ZTN compared to the native ligand curcumin. In vitro studies indicated that caffeic acid has certain anti-proliferative effects on U87 and small benefits on NHA viability. A. nemorosa extracts indicated potential benefits on NHA viability, and likely dangerous effects on U87.

Binge-like mephedrone treatment induces memory impairment concomitant with brain kynurenic acid reduction in mice

While mephedrone (4-methylmethcathinone), a synthetic cathinone derivative, is widely abused by adolescents and young adults, the knowledge about its long-term effects on memory processes is limited. Kynurenic acid (KYNA) is a neuroactive metabolite of the kynurenine pathway of tryptophan degradation. KYNA is considered an important endogenous modulator influencing physiological and pathological processes, including learning and memory processes. The aim of this study was to determine whether (A) binge-like mephedrone administration (10.0 and 30.0 mg/kg, intraperitoneally, in 4 doses separated by 2 h) induces memory impairments, assessed 2, 8 and 15 days after mephedrone cessation in the passive avoidance test in mice, and whether (B) KYNA is involved in these memory processes. To clarify the role of KYNA in the mephedrone effects, its production in the murine brain in vivo, and in cortical slices in vitro, as well as the activities of kynurenine aminotransferases (KATs) I and II were assessed. Furthermore, cell line experiments were conducted to investigate the effects of mephedrone on normal human brain cells. Our results showed memory impairments 8 and 15 days after binge-like mephedrone administration. At the same time, reduction in the KYNA level in the murine brain was noted. In vitro studies showed no effect of mephedrone on the production of KYNA in cortical slices or on the activity of the KAT I and II enzymes. Finally, exposure of normal cells to mephedrone in vitro resulted in a modest reduction of cell viability and proliferation.

Analysis of Cellular Heterogeneity in Immune Microenvironment of Primary Central Nervous System Lymphoma by Single-Cell Sequencing.

BackgroundPrimary central nervous system lymphoma (PCNSL) is characterized by a lack of specificity and poor prognosis. Further understanding of the tumor heterogeneity and molecular phenotype of PCNSL is of great significance for improving the diagnosis and treatment of this disease.MethodsTo explore the distinct phenotypic states of PCNSL, transcriptome-wide single-cell RNA sequencing was performed on 34,851 PCNSL cells from patients. The cell types, heterogeneity, and gene subset enrichment of PCNSL were identified. A comparison of the PCNSL cells with 21,250 normal human fetal brain (nHFB) cells was further analyzed to reveal the differences between PCNSL and normal sample.ResultsSix cell populations were mainly identified in the PCNSL tissue, including four types of immune cells—B cell, T cell, macrophage and dendritic cell—and two types of stromal cells: oligodendrocyte and meningeal cell. There are significant cellular interactions between B cells and several other cells. Three subpopulations of B cells indicating diffident functions were identified, as well as a small number of plasma cells. Different subtypes of T cells and dendritic cells also showed significant heterogeneity. It should be noted that, compared with normal, the gene expression and immune function of macrophages in PCNSL were significantly downregulated, which may be another important feature of PCNSL in addition to B cell lesions and may be a potential target for PCNSL therapy.

LncRNA TCONS_00004099-derived microRNA regulates oncogenesis through PTPRF in gliomas.

BackgroundGlioblastoma is the most common and aggressive primary tumor in the central nervous system (CNS). Patients with glioblastomas have poor prognosis due to its aggressive clinical behavior and resistance to the chemotherapeutic agent temozolomide (TMZ). Aberrant long non-coding RNAs (lncRNAs) are involved in glioma progression and its regulatory mechanisms. Analysis of sequencing data identified a new lncRNA, named lncRNA TCONS_00004099, which could derive a new microRNA and was highly expressed in glioma.MethodsTo elucidate the role of lncRNA TCONS_00004099 in gliomas, Quantitative Real-time PCR (qPCR) was used to assess the differential expression of lncRNA TCONS_00004099 and its related miRNA in glioma tissues, normal brain tissues, glioma cell lines (U87 and U251 cells), and a normal human embryonic brain cell line (HEB). Cell Counting Kit-8 (CCK8) assays to assess cell proliferation, flow cytometry assays examining apoptosis and the cell cycle, colony formation assays, wound healing assay, transwell assays, and zebrafish xenograft models were performed to further clarify the effects of the lncRNA and the related miRNA. Finally, Western blots were carried out to verify the mechanisms related to PTPRF (Protein Tyrosine Phosphatase Receptor Type F).ResultsLncRNA TCONS_00004099 was significantly increased in glioma tissues and glioma cell lines. A novel miRNA (miRNA TCONS_00004099) derived from the lncRNA was identified by qPCR. Knockdown of this lncRNA suppressed cell proliferation, migration, invasion and enhanced TMZ-induced apoptosis in U87 and U251 cell lines in vitro and in vivo. The miRNA mimics or inhibitor of miRNA TCONS_00004099 was used to reverse the effects of knockdown or overexpression of lncRNA TCONS_00004099, respectively. Western Blot analyses verified that PTPRF is one of the downstream targets of lncRNA TCONS_00004099.ConclusionsThese results demonstrated that lncRNA TCONS_00004099 promoted malignant behaviors in gliomas, including proliferation, metastasis, and anti-apoptosis. The effect of lncRNA TCONS_00004099 was mediated through miRNA TCONS_00004099 and its target PTPRF. Thus, the lncRNA TCONS_00004099/miRNA/PTPRF axis may be a potential therapeutic target for gliomas.

Single-cell RNA-seq reveals that glioblastoma recapitulates a normal neurodevelopmental hierarchy

Cancer stem cells are critical for cancer initiation, development, and treatment resistance. Our understanding of these processes, and how they relate to glioblastoma heterogeneity, is limited. To overcome these limitations, we performed single-cell RNA sequencing on 53586 adult glioblastoma cells and 22637 normal human fetal brain cells, and compared the lineage hierarchy of the developing human brain to the transcriptome of cancer cells. We find a conserved neural tri-lineage cancer hierarchy centered around glial progenitor-like cells. We also find that this progenitor population contains the majority of the cancer’s cycling cells, and, using RNA velocity, is often the originator of the other cell types. Finally, we show that this hierarchal map can be used to identify therapeutic targets specific to progenitor cancer stem cells. Our analyses show that normal brain development reconciles glioblastoma development, suggests a possible origin for glioblastoma hierarchy, and helps to identify cancer stem cell-specific targets.

Abstract A13: Leveraging Zika virus and the immune system to treat glioblastoma

Abstract Glioblastoma (GBM) kills most adults within 2 years. One reason for inevitable recurrence is that GBM stem cells (GSCs) are resistant to existing therapies. Additionally, GBM is the hallmark example of an immunotherapy-resistant tumor. Since GSCs share properties with neural stem cells, we investigated whether the natural honing and lytic activity of Zika virus (ZIKV) could be harnessed to target and kill GSCs. We published the first use of ZIKV to kill GSCs: ZIKV kills GSCs in tumors removed from patients, with minimal impact on non-GSC tumor cells and importantly, normal human brain cells were not affected by ZIKV. In vivo, ZIKV more than doubled median survival in immunocompetent mice bearing orthotopic gliomas, and in 40-50% of cases, mice were cured. In new unpublished work, we assessed brains of mice treated with ZIKV and found that treatment induces a robust inflammatory response. Using MHC-I tetramers presenting ZIKV envelope (E) protein or luciferase peptides (expressed in the tumor cells), we found that CD8+ T cells in the region of the tumor respond to both ZIKV and tumor, and anti-tumor CD8+ T cells are increased after ZIKV infection compared to vehicle. Additionally, cured mice were protected against tumor rechallenge, suggesting ZIKV induces immunologic memory that can surveil against recurrence. Using blocking antibodies, we discovered that CD8+ T cells are required for the efficacy of ZIKV, and CD8+ T cells are required for long-term protection. Our findings suggest that ZIKV may be an effective therapy for GBM for two reasons: its direct targeting of treatment-resistant tumor cells in turn produces an antitumor inflammatory response. Such a response may now be further leveraged by immunotherapies. Citation Format: Arijita Jash, Jennifer Govero, Sharmila Nair, Michael S. Diamond, Milan G. Chheda. Leveraging Zika virus and the immune system to treat glioblastoma [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr A13.

Multimodal quantitative imaging of brain cancer in cultured cells.

Fluorescence emission, polarization and subcellular localization of methylene blue (MB) were studied in four cancerous and two normal human brain cell lines. Fluorescence emission and polarization images were acquired and analyzed. The co-localization of MB with mitochondria, lysosomes and nuclei of the cells was evaluated. Glioblastoma cells exhibited significantly higher MB fluorescence polarization compared to normal astrocytes. Preferential accumulation of MB in mitochondria of glioblastoma cells may explain higher fluorescence polarization values in cancer cells as compared to normal. These findings may lead to the development of a quantitative method for the detection of brain cancer in single cells.

Abstract 1896: Blockade of laminin-411-notch crosstalk as an effective therapy for glioblastoma treatment

Abstract Purpose: The extracellular matrix (ECM) in tumor microenvironment including laminins is important for tumor development, and we aimed to develop an effective glioblastoma therapy via blocking the communication between tumor and their microenvironment mediated by laminin-411-Notch axis. Methods: The glioma vascular protein, laminin-411(α4β1γ1) expression was examined in >200 glioma patient specimens by immunohistochemistry. In glioblastoma bearing mice, laminin-411 expression in tumor cells was disrupted by CRISPR/Ca9 system, and its impact on two glioblastoma cell lines was studied in intracranial xenografts. Laminin-411-Notch crosstalk was further dissected in vitro using cell cultures. Finally, a nanobioconjugate was developed to block laminin-411 expression in vivo. The effects of blocking laminin-411-Notch axis via systemic administration of this nanodrug were investigated in vivo using MRI, immunohistochemistry, western blot and survival analysis. Results: Laminin-411 (α4β1γ1) expression in a panel of 226 patient brain glioma samples was correlated with higher tumor grade, and expression of cancer stem cell (CSC) markers including Notch pathway, CD133, Nestin, and c-Myc. Laminin-411 overexpression was also correlated with higher recurrence rate and shorter survival of glioma patients. Depletion of laminin-411 α4 and β1 chains with CRISPR/Cas9 in human glioblastoma cells led to slower growth of resultant intracranial tumors compared to wild type tumors as revealed by MRI. Concomitantly, survival of host animals carrying the laminin-411 knockout tumors was significantly increased. Mechanistic studies in vitro and in vivo showed that laminin-411 inhibition suppressed Notch pathway in both normal and malignant human brain cell types. A nanobioconjugate potentially suitable for clinical use and capable of crossing blood-brain barrier was designed to block laminin-411 expression. Nanobioconjugate treatment of mice carrying intracranial glioblastoma significantly increased animal survival and inhibited multiple CSC markers including Notch axis. Conclusion: The depletion of “malignant” laminin-411 α4 and β1 chains with CRISPR/Cas9 led to slower growth of resultant intracranial tumors compared to wild type tumors, and a systemic nanodrug treatment to inhibit laminin-411-Notch crosstalk provides a new strategy for glioblastoma treatment. This study demonstrates a new strategy of glioblastoma treatment through targeting a critical component of tumor microenvironment, largely independent of heterogeneous genetic mutations in the tumor. Citation Format: Dmytro Klymyshyn, Anna Galstyan, Rameshwar Patil, Hui Ding, Ekaterina Shatalova, Shawn Wagner, Keith Black, Alexander Ljubimov, Eggehard Holler, Julia Ljubimova, Tao Sun. Blockade of laminin-411-notch crosstalk as an effective therapy for glioblastoma treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1896.

Blockade of a Laminin-411-Notch Axis with CRISPR/Cas9 or a Nanobioconjugate Inhibits Glioblastoma Growth through Tumor-Microenvironment Cross-talk.

There is an unmet need for the treatment of glioblastoma multiforme (GBM). The extracellular matrix, including laminins, in the tumor microenvironment is important for tumor invasion and progression. In a panel of 226 patient brain glioma samples, we found a clinical correlation between the expression of tumor vascular laminin-411 (α4β1γ1) with higher tumor grade and with expression of cancer stem cell (CSC) markers, including Notch pathway members, CD133, Nestin, and c-Myc. Laminin-411 overexpression also correlated with higher recurrence rate and shorter survival of GBM patients. We also showed that depletion of laminin-411 α4 and β1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of resultant intracranial tumors in mice and significantly increased survival of host animals compared with mice with untreated cells. Inhibition of laminin-411 suppressed Notch pathway in normal and malignant human brain cell types. A nanobioconjugate potentially suitable for clinical use and capable of crossing blood-brain barrier was designed to block laminin-411 expression. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, including the Notch axis. This study describes an efficient strategy for GBM treatment via targeting a critical component of the tumor microenvironment largely independent of heterogeneous genetic mutations in glioblastoma.Significance: Laminin-411 expression in the glioma microenvironment correlates with Notch and other cancer stem cell markers and can be targeted by a novel, clinically translatable nanobioconjugate to inhibit glioma growth.

3352 Surgical Adjuvant of Immunomodulatory Gene Circuits for Treatment of Glioblastoma

OBJECTIVES/SPECIFIC AIMS: Glioblastoma (GBM) is a brain cancer with a devastatingly short overall survival of under two years. The poor prognosis of GBM is largely due to cell invasion and maintenance of cancer initiating cells that evade the brain’s innate and adaptive immune responses which enables escape from surgical resection and drives inevitable recurrence. While targeting the brain’s immune microenvironment has long been proposed as a strategy for treating GBM, translational progress has been slow, underscoring the need to investigate the brain’s immune microenvironment for therapeutic avenues. METHODS/STUDY POPULATION: Recent advancements in tunable synthetic immunomodulatory gene circuits targeting metastatic cancers has demonstrated the novel ability to use engineering principles to induce infiltrative cancer cells to express combinatorial immunomodulatory outputs that enable T-cell killing4. Our central hypothesis is: we will be able to significantly improve survival with a lasting immune-mediated control of GBM by using synthetic immunomodulatory gene circuits driving GBM cells to express a local combination of immunomodulatory proteins: human IL15, a surface T-cell engager, PD-L1-CD3 bispecific antibody, and the protein, LIGHT (TNFRSF14). Importantly, the co-expression of LIGHT and anti-PD-L1 therapies was recently shown to rescue PD-L1 checkpoint blockage in the preclinical models of brain tumors and significant enhance survival outcomes highlighting the benefits of novel combinations of immunomodulatory proteins for treatment of GBM. To identify genes whose expression is dramatically upregulated in GBM compared to normal human brain cells, a pooled of six thousand lentiviral oncogene promoters that drive expression of a red-fluorescent protein has been infected into three human GBM cell lines. RESULTS/ANTICIPATED RESULTS: We have successfully infected our GBM cells and are preparing samples for next generation DNA sequencing to determine highly active promoters in GBM that are not expressed in multiple normal brain cells types, astrocytes and neurons. These chosen promoters will then be used to drive an AND gate logic gene circuit immunotherapy outputs which is currently under development for both in-vitro and in-vivo experiments. DISCUSSION/SIGNIFICANCE OF IMPACT: We anticipate that local expression of multiple immune effectors proteins will significantly enhance tumor control and survival in both synergistic murine and human-murine xenograft pre-clinical models of GBM. Ultimately, our goal is to rapidly translate this technology advance into the clinical trial for adult GBM patients.

Radiation resistance of normal human astrocytes: the role of non-homologous end joining DNA repair activity.

Radiotherapy is a common modality for treatment of brain cancers, but it can induce long-term physiological and cognitive deficits. The responses of normal human brain cells to radiation is not well understood. Astrocytes have been shown to have a variety of protective mechanisms against oxidative stress and have been shown to protect neurons. We investigated the response of cultured normal human astrocytes (NHAs) to X-ray irradiation. Following exposure to 10 Gy X-irradiation, NHAs exhibited DNA damage as indicated by the formation of γ-H2AX foci. Western blotting showed that NHAs displayed a robust increase in expression of non-homologous end joining DNA repair enzymes within 15 min post-irradiation and increased expression of homologous recombination DNA repair enzymes ~2 h post-irradiation. The cell cycle checkpoint protein p21/waf1 was upregulated from 6–24 h, and then returned to baseline. Levels of DNA repair enzymes returned to basal ~48 h post-irradiation. NHAs re-entered the cell cycle and proliferation was observed at 6 days. In contrast, normal human mesenchymal stem cells (MSCs) failed to upregulate DNA repair enzymes and instead displayed sustained upregulation of p21/waf1, a cell cycle checkpoint marker for senescence. Ectopic overexpression of Ku70 was sufficient to protect MSCs from sustained upregulation of p21/waf1 induced by 10 Gy X-rays. These findings suggest that increased expression of Ku70 may be a key mechanism for the radioresistance of NHAs, preventing their accelerated senescence from high-dose radiation. These results may have implications for the development of novel targets for radiation countermeasure development.

The investigation of the pyrethroid insecticide lambda-cyhalothrin (LCT)-affected Ca2+ homeostasis and -activated Ca2+-associated mitochondrial apoptotic pathway in normal human astrocytes: The evaluation of protective effects of BAPTA-AM (a selective Ca2+ chelator)

Exposure to insecticides has been found to have deleterious effects on human health. Lambda-cyhalothrin (LCT), a mixture of isomers of cyhalothrin, is a pyrethroid insecticide routinely used in pest control programs. LCT was reported to cause neurotoxic effects in various models. However, the mechanism of underlying effect of LCT on cytotoxicity in normal human brain cells is still elusive. This study examined whether LCT affected Ca2+ homeostasis and Ca2+-related physiology in Gibco® Human Astrocytes (GHA cells), and explored whether BAPTA-AM (1,2-bis(2-aminophenoxy)ethane-N,N,N'N'-tetraacetic acid), a selective Ca2+ chelator, has protective effects on LCT-treated GHA cells. The data show that LCT (10–15 μM) concentration-dependently induced cytotoxicity in both GHA cells and DI TNC1 normal rat astrocytes but only induced intracellular Ca2+ concentration ([Ca2+]i) rises in GHA cells. In terms of Ca2+ signaling in GHA cells, LCT-induced [Ca2+]i rises were reduced by removing extracellular Ca2+ and were inhibited by store-operated Ca2+ channel modulators (2-APB, econazole or SKF96365). In Ca2+-free medium, pretreatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin abolished LCT-induced [Ca2+]i rises. Conversely, incubation with LCT abolished thapsigargin-induced [Ca2+]i rises. Regarding cytotoxicity, LCT evoked apoptosis by regulating apoptotic protein expressions (Bax, BCl-2, cleaved caspase-9/-3). This apoptotic response was significantly inhibited by prechelating cytosolic Ca2+ with BAPTA-AM. Together, in GHA cells, LCT induced [Ca2+]i rises by inducing Ca2+ entry via store-operated Ca2+ channels and Ca2+ release from the endoplasmic reticulum. Moreover, BAPTA-AM has a protective effect on inhibiting LCT-activated mitochondrial apoptotic pathway. This study provided new insights into the molecular protective mechanism of LCT-induced cytotoxicity in normal human astrocytes.

Differential gene expression analysis in glioblastoma cells and normal human brain cells based on GEO database.

The differentially expressed genes between glioblastoma (GBM) cells and normal human brain cells were investigated to performed pathway analysis and protein interaction network analysis for the differentially expressed genes. GSE12657 and GSE42656 gene chips, which contain gene expression profile of GBM were obtained from Gene Expression Omniub (GEO) database of National Center for Biotechnology Information (NCBI). The ‘limma’ data packet in ‘R’ software was used to analyze the differentially expressed genes in the two gene chips, and gene integration was performed using ‘RobustRankAggreg’ package. Finally, pheatmap software was used for heatmap analysis and Cytoscape, DAVID, STRING and KOBAS were used for protein-protein interaction, Gene Ontology (GO) and KEGG analyses. As results: i) 702 differentially expressed genes were identified in GSE12657, among those genes, 548 were significantly upregulated and 154 were significantly downregulated (p<0.01, fold-change >1), and 1,854 differentially expressed genes were identified in GSE42656, among the genes, 1,068 were significantly upregulated and 786 were significantly downregulated (p<0.01, fold-change >1). A total of 167 differentially expressed genes including 100 upregulated genes and 67 downregulated genes were identified after gene integration, and the genes showed significantly different expression levels in GBM compared with normal human brain cells (p<0.05). ii) Interactions between the protein products of 101 differentially expressed genes were identified using STRING and expression network was established. A key gene, called CALM3, was identified by Cytoscape software. iii) GO enrichment analysis showed that differentially expressed genes were mainly enriched in ‘neurotransmitter:sodium symporter activity’ and ‘neurotransmitter transporter activity’, which can affect the activity of neurotransmitter transportation. KEGG pathway analysis showed that the differentially expressed genes were mainly enriched in ‘protein processing in endoplasmic reticulum’, which can affect protein processing in endoplasmic reticulum. The results showed that: i) 167 differentially expressed genes were identified from two gene chips after integration; and ii) protein interaction network was established, and GO and KEGG pathway analyses were successfully performed to identify and annotate the key gene, which provide new insights for the studies on GBN at gene level.

SEPT7 overexpression inhibits glioma cell migration by targeting the actin cytoskeleton pathway.

Glioma cell metastasis is a serious obstacle for surgical treatment and prognosis, of which locomotion of the cytoskeleton is a key contributor of cancer cell spreading. SEPT7 is documented as a cytoskeletal protein with GTPase activity and involved in glioma progression. However, the underlying mechanism of SEPT7 in glioma invasion remains unresolved. Our study investigated whether SEPT7 influences glioma cell migration involved in cytoskeleton modulation. The SEPT7 expression in various glioma cell lines was markedly decreased compared to in normal human brain cells. It was demonstrated that SEPT7 overexpression significantly inhibits LN18 cell migration and chemotaxis induced by IGF‑1 (P<0.01 and P<0.01). Moreover, MMP‑2 and MMP‑9 were dramatically depressed after SEPT7 upregulation. To understand the mechanisms by which SEPT7 modulates homeostasis of the actin cytoskeleton, the F‑actin/G‑actin ratio and cofilin expression were determined. The data revealed that the F‑actin/G‑actin ratio and cofilin were reduced, and p‑cofilin increased conversely in cells with SEPT7 overexpression, indicating that SEPT7 reduced glioma cell migration by promoting cofilin phosphorylation and depolymerizing actin. Then, to understand the role of cofilin in SEPT7‑mediated actin dynamic equilibrium and cell migration, cofilin siRNA was transfected into cells. Surprisingly, cell migration and actin polymerization which had been improved by SEPT7 siRNA were significantly reversed, and the accompanying cofilin phosphorylation increased, indicating that cofilin phospho‑regulation played an important role in SEPT7‑mediated cytoskeleton locomotion and glioma cell migration. In conclusion, SEPT7 is involved in glioma cell migration with the assistance of cofilin phospho‑mediated cytoskeleton locomotion.

Ionizing Radiation Perturbs Cell Cycle Progression of Neural Precursors in the Subventricular Zone Without Affecting Their Long-Term Self-Renewal

Damage to normal human brain cells from exposure to ionizing radiation may occur during the course of radiotherapy or from accidental exposure. Delayed effects may complicate the immediate effects resulting in neurodegeneration and cognitive decline. We examined cellular and molecular changes associated with exposure of neural stem/progenitor cells (NSPs) to 137Cs γ-ray doses in the range of 0 to 8 Gy. Subventricular zone NSPs isolated from newborn mouse pups were analyzed for proliferation, self-renewal, and differentiation, shortly after irradiation. Strikingly, there was no apparent increase in the fraction of dying cells after irradiation, and the number of single cells that formed neurospheres showed no significant change from control. Upon differentiation, irradiated neural precursors did not differ in their ability to generate neurons, astrocytes, and oligodendrocytes. By contrast, progression of NSPs through the cell cycle decreased dramatically after exposure to 8 Gy (p < .001). Mice at postnatal day 10 were exposed to 8 Gy of γ rays delivered to the whole body and NSPs of the subventricular zone were analyzed using a four-color flow cytometry panel combined with ethynyl deoxyuridine incorporation. Similar flow cytometric analyses were performed on NSPs cultured as neurospheres. These studies revealed that neither the percentage of neural stem cells nor their proliferation was affected. By contrast, γ-irradiation decreased the proliferation of two classes of multipotent cells and increased the proliferation of a specific glial-restricted precursor. Altogether, these results support the conclusion that primitive neural precursors are radioresistant, but their proliferation is slowed down as a consequence of γ-ray exposure.

SC-03 * PAR1 INHIBITION SUPPRESSES A2B5-DEFINED GLIOMA PROGENITOR CELLS AND THEIR DERIVED GLIOMAS IN VIVO

In a comparison of gene expression by A2B5-defined glial tumor progenitor cells (TPCs) to glial progenitor cells derived from normal adult human brain (Cell Reports 3:2127-41, 2013), we found that the F2R gene encoding PAR1 was differentially over-expressed by TPCs isolated from primary gliomas at every stage of glioma progression. In this study, we therefore asked if PAR1 activation was causally associated with glioma progression. Lentiviral shRNAi knock-down of PAR1 inhibited the expansion and proliferation of glioma TPCs in vitro. We further found that the PAR-1 receptor antagonists SCH79797 and SCH530348 (vorapaxar) inhibited A2B5+ TPC expansion and migration in vitro. PAR1 knockdown also suppressed the tumorigenic potential of A2B5+ TPCs after transplantation into the brains of immunodeficient mice. In addition, mice given subcutaneous grafts of A2B5+ human glioma TPCs exhibited delayed tumor growth if treated with Vorapaxar, relative to xenografted control mice treated with only vehicle. Together, these data suggest that PAR1 may contribute to glioma progenitor expansion and tumor growth; as such, the abrogation of PAR1 signaling may contribute to the treatment of malignant glioma.

Human brain derived cells respond in a type-specific manner after exposure to urban particulate matter (PM)

Exposure to particulate matter (PM), a component of urban air pollution, may cause adverse effects in the brain. Although the exact mechanisms involved are unknown, both oxidative and inflammatory responses have been reported. Since the main route of exposure to particulate matter is through inhalation, there is a potential for compounds to directly enter the brain and alter normal cellular function. Enhancement in both oxidative stress and neuroinflammatory markers has been observed in neurodegenerative disorders and PM-induced potentiation of these events may accelerate the disease process. The objective of this pilot study was to use normal human brain cells, a model system which has not been previously used, to assess cell-type-specific responses after exposure to ultrafine particles (UFP). Human microglia, neurons, and astrocytes were grown separately or as co-cultures and then exposed to aqueous UFP suspensions. Reactive Oxygen Species (ROS) formation and the proinflammatory cytokine tumor necrosis factor alpha (TNF-α) were measured as markers of oxidative stress or inflammation respectively. Our results revealed that after exposure to 2μg/ml of particles, normal human neurons exhibit a decrease in ROS formation and an increase in TNF-α. The observed decrease in ROS formation persisted in the presence of glial cells, which contrasts previous studies done in rodent cells reporting that PM-induced microglial activation modulates neuronal responses. Our study indicates that human CNS cells may respond differently compared to rodent cells and that their use may be more predictive in risk assessment.

Effects of Ionizing Radiation on Neural Precursor Cells (P02.023)

Objective: To elucidate cellular and molecular changes associated with the exposure of neural stem cells (NSCs) to high and low doses of ionizing radiation. Background Damage to normal human brain cells from targeted exposure to ionizing radiation may occur during the course of cancer radiotherapy or from accidental exposure. Delayed effects may complicate the acute immediate effects, and in particular have been associated with neurodegeneration and cognitive decline. These delayed effects may arise from the slow death of irradiated cells, damage to cells that survive the radiation exposure, or from negative effects on normal cell replenishment of non-targeted brain cells from neural stem cells. Design/Methods: Subventricular zone (SVZ) neural precursors isolated from newborn mouse pups were analyzed for survival, proliferation and differentiation after exposure to low and high doses of γ rays (range from 0 to 8 Gy). Results: The ability of the neurospheres to differentiate into astroglia, neurons, and oligodendroglia was assessed in the studied groups 8 days after irradiation. There were no significant changes in the neurosphere differentiation ability between the irradiated cells and controls (p>0.05). Surprisingly, the number of neurospheres formed showed no significant change from control, up to 8 Gy of γ irradiation. Meanwhile, the size of the spheres increased slightly at low doses without any significant change(0.4 or 0.5 Gy), and decreased dramatically at 8 Gy (p Conclusions: Our data suggest that neural stem cells/neural precursors derived from the SVZ are resistant to ionizing irradiation. However, their proliferation is inhibited subsequent to exposure to ionizing radiation. Supported by: Start up fund. Disclosure: Dr. Chen has nothing to disclose. Dr. Levison has nothing to disclose. Dr. De Toledo has nothing to disclose. Dr. Azzam has nothing to disclose. Dr. Souayah has received personal compensation for activities with Walgreens as a consultant. Dr. Souayah has received research support from Talecris.