scholarly journals HGG-21. MALIGNANT SYNAPTIC PLASTICITY IN PEDIATRIC HIGH-GRADE GLIOMAS

2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i21-i21
Author(s):  
Kathryn Taylor ◽  
Tara Barron ◽  
Griffin Hartmann ◽  
Helena Zhang ◽  
Alexa Hui ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Glioma Cells ◽  
Membrane Properties ◽  
High Grade ◽  
Synaptic Regulation ◽  
Electrophysiological Recordings ◽  
Glioma Xenograft ◽  
Synaptic Neurotransmission ◽  
High Grade Gliomas ◽  
Cell Depolarization

Abstract Pediatric high-grade gliomas (pHGG) are a devastating group of diseases that urgently require novel therapeutic options. We have previously demonstrated that pHGGs directly synapse onto neurons and the subsequent tumor cell depolarization, mediated by calcium-permeable AMPA channels, promotes their proliferation. The regulatory mechanisms governing these postsynaptic connections are unknown. Here, we investigated the role of BDNF-TrkB signaling in modulating the plasticity of the malignant synapse. BDNF ligand activation of its canonical receptor, TrkB (which is encoded for by the gene NTRK2), has been shown to be one important modulator of synaptic regulation in the normal setting. Electrophysiological recordings of glioma cell membrane properties, in response to acute neurotransmitter stimulation, demonstrate in an inward current resembling AMPA receptor (AMPAR) mediated excitatory neurotransmission. Extracellular BDNF increases the amplitude of this glutamate-induced tumor cell depolarization and this effect is abrogated in NTRK2 knockout glioma cells. Upon examining tumor cell excitability using in situ calcium imaging, we found that BDNF increases the intensity of glutamate-evoked calcium transients in GCaMP6s expressing glioma cells. Western blot analysis indicates the tumors AMPAR properties are altered downstream of BDNF induced TrkB activation in glioma. We find that BDNF-TrkB signaling promotes neuron-to-glioma synaptogenesis as measured by high-resolution confocal and electron microscopy in culture and tumor xenografts. Our analysis of published pHGG transcriptomic datasets, together with brain slice conditioned medium experiments in culture, indicate the tumor microenvironment as the chief source of BDNF ligand. Disruption of the BDNF-TrkB pathway in patient-derived orthotopic glioma xenograft models, both genetically and pharmacologically, results in an increased overall survival and reduced tumor proliferation rate. These findings suggest that gliomas leverage mechanisms of plasticity to modulate the excitatory channels involved in synaptic neurotransmission and they reveal the potential to target the regulatory components of glioma circuit dynamics as a therapeutic strategy for these lethal cancers.

scholarly journals Study of the biodistribution of fluorescein in glioma-infiltrated mouse brain and histopathological correlation of intraoperative findings in high-grade gliomas resected under fluorescein fluorescence guidance

2015 ◽  
Vol 122 (6) ◽  
pp. 1360-1369 ◽  
Author(s):  
Roberto Jose Diaz ◽  
Roberto Rey Dios ◽  
Eyas M. Hattab ◽  
Kelly Burrell ◽  
Patricia Rakopoulos ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Low Dose ◽  
Glioma Cells ◽  
High Grade ◽  
Fluorescein Sodium ◽  
Tumor Margins ◽  
Histopathological Correlation ◽  
High Grade Gliomas

OBJECT Intravenous fluorescein sodium has been used during resection of high-grade gliomas to help the surgeon visualize tumor margins. Several studies have reported improved rates of gross-total resection (GTR) using high doses of fluorescein sodium under white light. The recent introduction of a fluorescein-specific camera that allows for high-quality intraoperative imaging and use of very low dose fluorescein has drawn new attention to this fluorophore. However, the ability of fluorescein to specifically stain glioma cells is not yet well understood. METHODS The authors designed an in vitro model to assess fluorescein uptake in normal human astrocytes and U251 malignant glioma cells. An in vivo experiment was also subsequently designed to study fluorescein uptake by intracranial U87 malignant glioma xenografts in male nonobese diabetic/severe combined immunodeficient mice. A genetically induced mouse glioma model was used to adjust for the possible confounding effect of an inflammatory response in the xenograft model. To assess the intraoperative application of this technology, the authors prospectively enrolled 12 patients who underwent fluorescein-guided resection of their high-grade gliomas using low-dose intravenous fluorescein and a microscope-integrated fluorescence module. Intraoperative fluorescent and nonfluorescent specimens at the tumor margins were randomly analyzed for histopathological correlation. RESULTS The in vitro and in vivo models suggest that fluorescein demarcation of glioma-invaded brain is the result of distribution of fluorescein into the extracellular space, most likely as a result of an abnormal blood-brain barrier. Glioblastoma tumor cell–specific uptake of fluorescein was not observed, and tumor cells appeared to mostly exclude fluorescein. For the 12 patients who underwent resection of their high-grade gliomas, the histopathological analysis of the resected specimens at the tumor margin confirmed the intraoperative fluorescent findings. Fluorescein fluorescence was highly specific (up to 90.9%) while its sensitivity was 82.2%. False negatives occurred due to lack of fluorescence in areas of diffuse, low-density cellular infiltration. Margins of contrast enhancement based on intraoperative MRI–guided StealthStation neuronavigation correlated well with fluorescent tumor margins. GTR of the contrast-enhancing area as guided by the fluorescent signal was achieved in 100% of cases based on postoperative MRI. CONCLUSIONS Fluorescein sodium does not appear to selectively accumulate in astrocytoma cells but in extracellular tumor cell-rich locations, suggesting that fluorescein is a marker for areas of compromised blood-brain barrier within high-grade astrocytoma. Fluorescein fluorescence appears to correlate intraoperatively with the areas of MR enhancement, thus representing a practical tool to help the surgeon achieve GTR of the enhancing tumor regions.

TAMI-28. IDENTIFICATION OF A NEUROLIGIN-3 BINDING PARTNER IN HIGH-GRADE GLIOMAS AND NORMAL PROGENITORS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi204-vi204
Author(s):  
Shawn Gillespie ◽  
Yoon Seok Kim ◽  
Anna Geraghty ◽  
Michael Quezada ◽  
James Reed ◽  
...  
Keyword(s):  
Neuronal Activity ◽  
Glioma Cells ◽  
Diffuse Intrinsic Pontine Glioma ◽  
Size Exclusion ◽  
Dependent Manner ◽  
High Grade ◽  
Gamma Secretase ◽  
Binding Partner ◽  
High Grade Gliomas

Abstract High-grade gliomas, including diffuse intrinsic pontine glioma, are lethal cancers whose progression is strongly regulated by neuronal activity. One way in which gliomas detect neuronal activity is via interaction with the ectodomain of post-synaptic adhesion protein neuroligin-3 (NLGN3), which is shed from neurons and oligodendrocyte precursors (OPCs) by the ADAM10 sheddase in an activity dependent manner. NLGN3 signaling drives glioma growth, but the cognate binding partner of shed NLGN3 (sNLGN3) on glioma cells is unknown. Here, we employed a proximity labeling technique to identify chondroitin sulfate proteoglycan 4 (CSPG4) as a putative binding partner of sNLGN3 in gliomas. We then confirmed complexing between recombinant proteins with size exclusion chromatography and are determining kinetics and affinity by surface plasmon resonance. When looking for evidence of binding in cells, we were surprised to find that sNLGN3 triggers regulated intramembrane proteolysis (RIP) of CSPG4, leaving no trace of the interaction at the membrane. sNLGN3 binding first induces ADAM10-mediated cleavage and release of the CSPG4 ectodomain, followed by gamma secretase-mediated release of the intracellular domain and downstream signaling in OPCs and gliomas. Pre-treatment of glioma cells or OPCs with an ADAM10 inhibitor entirely blocks sNLGN3-induced CSPG4 shedding. Acute depletion of CSPG4 via CRISPR gene editing renders glioma cells insensitive to the growth-promoting effects of sNLGN3 in vitro. Furthermore, we find that tamoxifen-induced deletion of NLGN3 from murine OPCs reduces the total number of OPCs, suggesting that this signaling axis promotes maintenance of OPC stemness in an autocrine fashion. Indeed, gamma secretase inhibition accelerates OPC differentiation in vitro, pointing towards a fundamental role for sNLGN3-CSPG4 signaling in OPCs and high-grade gliomas. Altogether, our results form a critical missing link in understanding how glioma cells detect a key neuronal activity-regulated signal, suggest intriguing links to OPC biology and identify a therapeutic target to disrupt neuron-glioma interactions.

TAMI-47. MIR-542-3P CONTRIBUTES TO THE HK2-MEDIATED HIGH GLYCOLYTIC PHENOTYPE IN HUMAN GLIOMA CELLS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi208-vi208
Author(s):  
Junhyung Kim ◽  
Min Woo Park ◽  
Ju Won Ahn ◽  
Jeong Min Sim ◽  
Suwan Kim ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Cellular Proliferation ◽  
Glioma Cells ◽  
Low Grade ◽  
High Grade ◽  
Human Glioma ◽  
Human Glioma Cells ◽  
Glycolytic Activity ◽  
High Grade Gliomas ◽  
Glycolytic Phenotype

Abstract BACKGROUND The elevation of glucose metabolism is linked to high-grade gliomas such as glioblastoma multiforme (GBM). The high glycolytic phenotype is associated with cellular proliferation and resistance to treatment with chemotherapeutic agents in GBM. MicroRNA-542-3p (miR-542-3p) has been implicated in several tumors including gliomas. However, the role of miR-542-3p in glucose metabolism in human gliomas remains unclear. METHODS We measured the levels of cellular proliferation in human glioma cells. We measured the glycolytic activity in miR-542-3p knockdown and over-expressed human glioma cells. We measured the levels of miR-542-3p and HK2 in glioma tissues from patients with low- and high-grade gliomas using imaging analysis. RESULTS We show that knockdown of miR-542-3p significantly suppressed cellular proliferation in human glioma cells. Knockdown of miR-542-3p suppressed HK2-induced glycolytic activity in human glioma cells. Consistently, over-expression of miR-542-3p increased HK2-induced glycolytic activity in human glioma cells. The levels of miR-542-3p and HK2 were significantly elevated in glioma tissues of patients with high-grade gliomas relative to that in low-grade gliomas. The elevation of HK2 levels in patients with high-grade gliomas were positively correlated with the high levels of miR-542-3p in GBM and low-grade gliomas (LGG) based on the datasets from the Cancer Genome Atlas (TCGA) database. Moreover, the high levels of miR-542-3p were associated with poor survival rate in the TCGA database. CONCLUSIONS miR-542-3p contributes to the HK2-mediated high glycolytic phenotype in human glioma cells.

scholarly journals PS2 - 178 Brevican-Specific Peptides for the Development of Next-Generation Targeted Theranostics for High Grade Gliomas

2016 ◽  
Vol 43 (S4) ◽  
pp. S14-S14
Author(s):  
C.F. Cho ◽  
K. Kasai ◽  
J. Wolfe ◽  
K. Hornburg ◽  
F. Bononi ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Glioma Cells ◽  
Specific Protein ◽  
Cell Uptake ◽  
Detection Methods ◽  
High Grade ◽  
Current Standard ◽  
Anti Cancer ◽  
High Grade Gliomas ◽  
Theranostic Agents

High-grade gliomas are deadly cancers, and current standard-of-care has demonstrated limited success. The ability to specifically target glioma cells can allow for the development of improved theranostic agents leading to better detection methods, as well as safer anti-cancer therapies. Brevican (Bcan), a CNS-specific protein is upregulated in glioma cells and correlates with tumor progression. Particularly, a Bcan isoform lacking normal glycosylation, called B/bDg is a unique glioma marker and is not expressed in non-cancerous tissues. Therefore, B/bDg represents a valuable target for anti-cancer strategies. We describe here the discovery of novel high-affinity B/bDg-targeted peptides using rapid combinatorial library screening approaches and a microfluidic sorting device of our own design. Briefly, a one-bead-one-compound (OBOC) peptide library was screened against small magnetic particles decorated with B/bDg. Positive “hit” beads labeled with magnetic particles were isolated using an inexpensive but yet, accurate and high-throughput in-house microfluidic magnetic-activated sorter. These hits were exposed to cells expressing B/bDg, and beads with the highest cell association were isolated and sequenced. Seven novel peptides were identified. Cell uptake analyses and blocking studies revealed that 5 of these peptides displayed specific uptake in B/bDg-overexpressing cells. These candidates displayed nano-/micromolar binding affinity for recombinant B/bDg protein. Further analyses of these candidates using confocal microscopy revealed increased peptide binding/uptake in patient-derived glioma stem cells (GSCs) compared with primary human astrocytes. We plan to incorporate these onto multi-functional BBB-penetrating nanoparticles loaded with imaging agents or a drug payload to translate them into highly selective and efficacious brain cancer theranostic agents.

Recombinant vesicular stomatitis virus vectors as oncolytic agents in the treatment of high-grade gliomas in an organotypic brain tissue slice—glioma coculture model

2004 ◽  
Vol 100 (6) ◽  
pp. 1049-1059 ◽  
Author(s):  
Christopher D. Duntsch ◽  
Qihong Zhou ◽  
Himangi R. Jayakar ◽  
James D. Weimar ◽  
Jon H. Robertson ◽  
...  
Keyword(s):  
Brain Tissue ◽  
Vesicular Stomatitis Virus ◽  
Glioma Cells ◽  
Tissue Slice ◽  
High Grade ◽  
Content Type ◽  
Coculture System ◽  
Vesicular Stomatitis ◽  
High Grade Gliomas ◽  
Fine Print

Object. The purpose of this study was to evaluate both replication-competent and replication-restricted recombinant vesicular stomatitis virus (VSV) vectors as therapeutic agents for high-grade gliomas by using an organotypic brain tissue slice—glioma coculture system. Methods. The coculture system involved growing different brain structures together to allow neurons from these tissues to develop synaptic connections similar to those found in vivo. Rat C6 or human U87 glioma cells were then introduced into the culture to evaluate VSV as an oncolytic therapy. The authors found that recombinant wild-type VSV (rVSV-wt) rapidly eliminated C6 glioma cells from the coculture, but also caused significant damage to neurons, as measured by a loss of microtubule-associated protein 2 immunoreactivity and a failure in electrophysiological responses from neurons in the tissue slice. Nonetheless, pretreatment with interferon beta (IFNβ) virtually eliminated VSV infection in healthy tissues without impeding any oncolytic effects on tumor cells. Despite the protective effects of the IFNβ pretreatment, the tissue slices still showed signs of cytopathology when exposed to rVSV-wt. In contrast, pretreatment with IFNβ and inoculation with a replication-restricted vector with its glycoprotein gene deleted (rVSV-ΔG) effectively destroyed rat C6 and human U87 glioma cells in the coculture, without causing detectable damage to the neuronal integrity and electrophysiological properties of the healthy tissue in the culture. Conclusions. Data in this study provide in vitro proof-of-principle that rVSV-ΔG is an effective oncolytic agent that has minimal toxic side effects to neurons compared with rVSV-wt and therefore should be considered for development as an adjuvant to surgery in the treatment of glioma.

scholarly journals miR-542-3p Contributes to the HK2-Mediated High Glycolytic Phenotype in Human Glioma Cells

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 633
Author(s):  
Junhyung Kim ◽  
Min Woo Park ◽  
Young Joon Park ◽  
Ju Won Ahn ◽  
Jeong Min Sim ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Cellular Proliferation ◽  
Glioma Cells ◽  
Low Grade ◽  
High Grade ◽  
Human Glioma ◽  
Human Glioma Cells ◽  
Glycolytic Activity ◽  
High Grade Gliomas ◽  
Glycolytic Phenotype

(1) Background: The elevation of glucose metabolism is linked to high-grade gliomas such as glioblastoma multiforme (GBM). The high glycolytic phenotype is associated with cellular proliferation and resistance to treatment with chemotherapeutic agents in GBM. MicroRNA-542-3p (miR-542-3p) has been implicated in several tumors including gliomas. However, the role of miR-542-3p in glucose metabolism in human gliomas remains unclear; (2) Methods: We measured the levels of cellular proliferation in human glioma cells. We measured the glycolytic activity in miR-542-3p knockdown and over-expressed human glioma cells. We measured the levels of miR-542-3p and HK2 in glioma tissues from patients with low- and high-grade gliomas using imaging analysis; (3) Results: We show that knockdown of miR-542-3p significantly suppressed cellular proliferation in human glioma cells. Knockdown of miR-542-3p suppressed HK2-induced glycolytic activity in human glioma cells. Consistently, over-expression of miR-542-3p increased HK2-induced glycolytic activity in human glioma cells. The levels of miR-542-3p and HK2 were significantly elevated in glioma tissues of patients with high-grade gliomas relative to that in low-grade gliomas. The elevation of HK2 levels in patients with high-grade gliomas were positively correlated with the high levels of miR-542-3p in GBM and low-grade gliomas (LGG) based on the datasets from the Cancer Genome Atlas (TCGA) database. Moreover, the high levels of miR-542-3p were associated with poor survival rate in the TCGA database; (4) Conclusions: miR-542-3p contributes to the HK2-mediated high glycolytic phenotype in human glioma cells.

Venous Thromboembolism and High Grade Gliomas

1993 ◽  
Vol 70 (03) ◽  
pp. 393-396 ◽  
Author(s):  
Mandeep S Dhami ◽  
Robert D Bona ◽  
John A Calogero ◽  
Richard M Hellman
Keyword(s):  
Risk Factors ◽  
Venous Thromboembolism ◽  
Medical Center ◽  
Significant Risk ◽  
Bleeding Complications ◽  
Fisher Exact Test ◽  
High Grade ◽  
Chi Square ◽  
Exact Test ◽  
High Grade Gliomas

SummaryA retrospective study was done to determine the incidence of and the risk factors predisposing to clinical venous thromboembolism (VTE) in patients treated for high grade gliomas. Medical records of 68 consecutive patients diagnosed and treated at Saint Francis Hospital and Medical Center from January 1986 to June 1991 were reviewed. The follow up was to time of death or at least 6 months (up to December 1991). All clinically suspected episodes of VTE were confirmed by objective tests. Sixteen episodes of VTE were detected in 13 patients for an overall episode rate of 23.5%. Administration of chemotherapy (p = 0.027, two tailed Fisher exact test) and presence of paresis (p = 0.031, two tailed Fisher exact test) were statistically significant risk factors for the development of VTE. Thrombotic events were more likely to occur in the paretic limb and this difference was statistically significant (p = 0.00049, chi square test, with Yates correction). No major bleeding complications were seen in the nine episodes treated with long term anticoagulation.We conclude that venous thromboembolic complications are frequently encountered in patients being treated for high grade gliomas and the presence of paresis and the administration of chemotherapy increases the risk of such complications.

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