bluuebunny/crossref_metadata_2025_split huggingface dataset:
CNSC-10. GLIOBLASTOMA CELLS IMITATE NEURON’S EXCITABILITY IN ACUTE AND ORGANOTYPIC HUMAN BRAIN SLICES
Authors: Tong Tong , Ozsvar Attila , Hou Wen-Hsien , Korshøj Anders 
Published: November 2023

Abstract
Glioblastoma (GBM) is a highly lethal cancer due to its inter- and intra-patient molecular and physiological heterogeneity, and its complex interaction with brain tissue. Recent findings demonstrate that Neuron-to-brain tumor-synaptic-communications (NBTSCs) engage in a vicious cycle of enhanced neuronal activity, driving glioma progression and invasion and tumor-induced epilepsy. However, the physiology of these synaptic interactions in the tumor-infiltrated human neocortex remains largely uncharacterized. To address this gap, our study focused on investigating the intrinsic electrical properties of glioma cells and NBTSCs in the tumor-infiltrated human cortex using a unique experimental workflow involving acute and cultured human tumor-infiltrated brain slices. Via an adeno-associated virus-assisted gene delivery technique, we selectively express fluorescence proteins in a cell-type specific manner. By performing fluorescence-guided whole-cell patch clamp recording, we characterized the electrophysiological properties of glioma cells and neurons under the tumor microenvironment. We observed that glioma cells from tumor-infiltrated human brain samples displayed depolarized resting membrane potential (-32.21 ± 2.1mV) and high input resistance (1.24 ± 0.18 GΩ). Approximately 69.2% of glioma cells exhibited spikelets or distorted-action potentials upon current injection. Consistent with other studies, a subset of glioma cells (11.8%) exhibited spontaneous excitatory postsynaptic currents (sEPSC). In addition, the tumor-infiltrated microenvironment significantly influences the proximal neurons’ physiology and the neuronal microcircuitry, leading to abnormal intrinsic electrical properties, depolarized resting membrane potential (-37.66 ± 4.32 mV), and a significant reduction in spontaneous synaptic input frequency. Collectively, our study consolidates the existence of NBTSCs in human cancer patients and reveals that glioma cells exhibit neuron-like excitability, which is contrary to the common understanding that they are considered as non-excitable. Under the tumor microenvironment, neurons display hyperexcitability. Our newly established organotypic human brain slice culture platform provides potential grounds for exploring further the biological characteristics of gliomas and NBTSCs.
CNSC-16. MOLECULAR PROFILING AND ACTIONABLE MUTATIONS IN ADULT PATIENTS WITH IDH WILD TYPE GLIOMAS AND GLIONEURONAL AND NEURONAL TUMORS
Authors: Pellerino Alessia , Marchesani Elena Maria , Bertero Luca , Ricci Alessia Andrea , Mangherini Luca , Bruno Francesco , Soffietti Riccardo , Rudà Roberta 
Published: November 2023

Abstract

BACKGROUND
Next generation sequencing (NGS) assays enable the identification of genetic alterations that may guide a personalized treatment in glioma patients. Material and

METHODS
From July 2021 to May 2023 a NGS analysis (Myriapod® NGS Cancer DNA and RNA panels) was performed in a cohort of 211 adults IDH wild type (wt) gliomas or circumscribed astrocytoma or glioneuronal/neuronal tumors. The aim was to identify actionable molecular alterations and provide targeted therapy at recurrence accordingly.

RESULTS
NGS analysis was available in 211 patients (95.5%), while NGS was not feasible in 10 patients (4.5%). 188/211 (89.1%) had an IDH wt glioblastoma (GBM) (median age 61 years), 6 (2.8%) had IDH wt lower grade gliomas (LGG) (median age 63 years), and 17 (8.1%) had circumscribed astrocytoma or glioneuronal/neuronal tumor (median age 37 years). Overall, actionable molecular alterations were found in 13/211 patients (6.2%). 7/211 patients (3.3%) had BRAF V600E mutation (3 IDH wt GBM, 1 IDH wt LGG, and 3 circumscribed/glioneuronal and neuronal tumor), 4/211 patients (1.9%) had FGFR3-TACC3 fusion (all GBM), 1/211 patients (0.5%) had PIK3CA mutation (GBM), and 1/211 patients (0.5%) had NTRK1 fusion (glioneuronal tumor). Other molecular mutations, including ALK, ERBB2, MET, KIT, KRAS, PDGFRA, and RET have not been detected. Three patients recurred after first-line therapy: 1 with BRAF mutated GBM, 1 with GBM harboring FGFR3-TACC3 fusion, and 1 with NTRK1 fusion positive glioneuronal tumor received specific BRAF/MEK inhibitor (dabrafenib/trametinib), FGFR inhibitor (pemigatinib), and NTRK inhibitor (larotrectinib), respectively. A remarkable activity of BRAF/MEK and NTRK inhibitors was observed (9 and 6 months, respectively *), while FGFR inhibitor did not display an activity to control disease (9 weeks). * ongoing

CONCLUSION
The incidence of actionable molecular alterations in IDH wt gliomas and glioneuronal/neuronal tumors was low. However, the use of targeted therapies may lead to significant impact on the outcome.
CNSC-19. HYPOXIA-INDUCED NEURONAL ACTIVITY IN GLIOMA PATIENTS POLARIZES MICROGLIA BY POTENTIATING RNA M6A DEMETHYLATION
Authors: Guo Xiaofan , Wei Qiu , Li Gang 
Published: November 2023

Abstract
Neuronal activity in the brain has been reported to promote the malignant progression of glioma cells via nonsynaptic paracrine and electrical synaptic integration mechanisms. However, the interaction between neuronal activity and the immune microenvironment in glioblastoma (GBM) remains largely unclear. In this study, by applying chemogenetic techniques, we enhanced and inhibited neuronal activity in vitro and in a mouse model to study how neuronal activity regulates microglial polarization and affects GBM progression. Here, we demonstrate that hypoxia induces glioma stem cells (GSCs) to produce glutamate, which activates local neurons. The hypoxia-induced neuronal activity promotes GBM progression by facilitating microglial M2 polarization. We found that when microglia were co-cultured with activated neurons, the level of RNA m6A methylation in microglia was impaired, which subsequently induced microglial M2 polarization. In the mouse model, cortical neuronal activation promoted regional microglial M2 polarization while cortical neuronal inhibition decreased regional microglial M2 polarization in GBM xenografts. Together, these findings indicate that hypoxic GSC-induced neuronal activation promotes GBM progression by polarizing microglia via decreasing their m6A methylation levels.
CNSC-21. INVESTIGATING THE EVOLUTION OF NEURON-GLIOMA CIRCUIT DYNAMICS USING AN IN VIVO IMAGING METHOD
Authors: Shamardani Kiarash , Keough Michael , Monje Michelle 
Published: November 2023

Abstract
Pediatric high-grade gliomas (pHGG) are aggressive primary brain neoplasms with a dismal prognosis, making them the leading cause of brain tumor-related deaths in children. pHGGs occur in specific anatomical locations at specific ages underscoring their origin in neurodevelopment and the critical importance of the brain tumor microenvironment. Activity-regulated mechanisms are major regulators of neural development and plasticity. Many pHGGs originate from oligodendroglial precursor cells (OPC) and, like OPCs, neuronal activity promotes pHGG proliferation. Recent work has demonstrated that pHGG cells form calcium-permeable AMPAR-mediated synapses with neurons analogous to the axo-glial synapses that form between neurons and OPCs. Neuronal activity drives pHGG growth through secretion of activity-regulated mitogens and through electrochemical communication with pHGG cells that integrate into neural circuits. In turn, pHGG increases neuronal excitability and remodels functional neural circuits. The interconnected network of glioma cells and neurons is fundamental to pHGG progression. However, how these neuron-glioma networks evolve over time remains to be fully understood. We hypothesize that as gliomas progress, the neuron-glioma malignant circuitry evolves chiefly through synaptogenesis to promote activity that fosters glioma progression. Thus, we developed a two-color in vivo imaging method to study neuron-glioma cell interactions over time in freely behaving mice enabling us to record the frequency, pattern, and synchronicity of calcium transients in neurons, glioma cells, and their coactivity giving us a comprehensive view of the changes in neuron-glioma circuit dynamics over time. We have observed increasing neuronal activity throughout the disease, consistent with increasing neural hyperexcitability over time, and have observed that different types of gliomas exhibit unique patterns of calcium transients (rise time, peak amplitude, decay time, and half-width). Our imaging paradigm offers a unique ability to study neuron-glioma interactions at the systems level and will allow us to study how pharmacological inhibitors and neuronal experience shape neuron-glioma malignant circuit dynamics.
CNSC-23. ROLE OF GLIAL PH-DEPENDENT METABOLIC REGULATION IN GLIOMA PROGRESSION
Authors: Ye Qi , Oh Heavin , Choy Tiffany , Madamba Christine , Serin-Harmanci Akdes , Rao Ganesh , Lee Hyun Kyoung 
Published: November 2023

Abstract
Malignant glioma is a devastating brain cancer with barely any improvement in prognosis over decades. One key mechanism for glioma invasiveness is the dynamic metabolic communication between glioma and surrounding cells shaping the tumor microenvironment. While extracellular acidosis is a pathological hallmark of glioma, pH-dependent mechanisms underlying tumor metabolic reprogramming remain poorly defined. Our study focuses on a glial-enriched sodium-bicarbonate cotransporter, Slc4a4, which was previously identified as intracellular and extracellular pH regulator. While Slc4a4-mediated pH regulation is important for physiological brain function and responses after injury, its role in glioma progression is largely undefined. To begin addressing this question, we analyzed The Cancer Genome Atlas (TCGA) database, finding high Slc4a4 expression correlates with prolonged survival in glioma patients. Corroboratively, Slc4a4 gain-of-function (GOF) drastically decreases tumorigenesis and angiogenesis in patient-derived-xenograft and CRISPR-mediated de novo mouse glioma models. These results are further complemented by loss-of-function (LOF) studies using glial-specific Slc4a4 knockout mice, suggesting an inhibitory role of Slc4a4 in glioma growth and associated angiogenesis. A combination of unbiased metabolomic and cancer-targeted proteomic profiling of Slc4a4 GOF/LOF mouse glioma reveals an inverse correlation between Slc4a4 and a key lipid metabolism protein, FABP5 (Fatty Acid Binding Protein 5), which is coupled with dysregulated lipid metabolism. Moreover, analysis of TCGA database shows inverse expression and survival correlation of Slc4a4 and FABP5 in glioma patients. Further functional study shows that overexpression of FABP5 reverses Slc4a4’s inhibitory effects on glioma growth in immunocompetent mouse glioma model, supporting a functional antagonism between Slc4a4 and FABP5. Together, our study indicates that Slc4a4 plays a protective role in glioma progression by regulating metabolic activities, providing critical insights into pH-dependent metabolic reprogramming in glioma.
CNSC-27. LOSS OF CAPICUA IMPAIRS OLIGODENDROGENESIS IN THE DEVELOPING MOUSE BRAIN
Authors: Pyczek Joanna , Hall Courtney F , Johnston Michael , Singhal Divya , Gallo Marco , Morrissy Sorana , Chan Jennifer 
Published: November 2023

Abstract

INTRODUCTION
70% of all oligodendrogliomas (ODG) harbor hemizygous loss-of-function Capicua (Cic) mutations. Cic is a transcriptional repressor downstream of MAPK signaling. Loss of Cic in neural precursors has been linked to increased proliferation and developmental bias towards differentiation-incompetent oligodendrocyte precursor cells (OPCs). This study aims to elucidate the consequences of OPC-specific Cic loss for oligodendroglia development and assess its contribution to ODG formation.

METHODS
Pdgfra-CreERT2;Cicfl/+;Rosa26EYFP (heterozygote control, Cic-HET) and Pdgfra-CreERT2;Cicfl/fl;Rosa26EYFP (homozygous knockout, Cic-KO) mice were used to induce Cic deletion and EYFP expression in OPCs during the postnatal wave of oligodendrocyte production (P3+P5). Double labeling with BrdU at P6 and EdU 6 hours prior to experimental endpoint was used to birthdate and assess active proliferation, respectively. Cic knockout was confirmed on the genomic level by qPCR. Formalin-fixed mouse brains were analyzed at 7-, 14- and 28-days post injection (dpi) for expression of proliferation and oligodendrocyte stage-specific markers by multiplex immunofluorescent staining. FACS-sorting was used to enrich for recombined cells based on EYFP expression. The 10x Genomics platform was used to analyze the single cell transcriptome (scRNAseq) of Cic-KO vs Cic-HET brains at designated time points.

RESULTS
7dpi Cic-KO brains displayed an increased percentage of Pdgfra+ OPCs (25.76% KO vs. 15.95% HET) and a decreased percentage of CC1+ mature oligodendrocytes (27.69% KO vs. 33.93% HET) compared to heterozygote control. Cic-KO OPCs showed an increased proliferation rate as demonstrated by higher frequency of Ki67+ (3.16% HET vs 7.26%KO) and EdU+ (22.47% HET vs 44.44% KO) cells. scRNAseq revealed upregulation of genes involved in “nervous system development” and downregulation of “myelination” program upon Cic knockout.

CONCLUSION
We showed that OPC-specific Cic knockout results in increased cellular proliferation and maturation defects in the developing mouse brain. Cic loss may contribute to ODG formation by promoting developmental programs and inhibiting oligodendrocyte maturation in postnatal OPCs.
CNSC-30. CD4 T CELLS MEDIATED UPREGULATION OF CCL4 CHEMOKINE DRIVES GLIOBLASTOMA TUMOR MICROENVIRONMENT REPROGRAMMING FOLLOWING TREATMENT WITH A NOVEL MRNA VACCINE
Authors: Chauhan Anjali , Ebrahim Ghaidaa , Dastmalchi Farhad , McGrath Kyle , Thomas Nagheme , Takacs Gregory Pal , Harrison Jeffrey , Frain Matthew , Mendez-Gomez Hector , Sayour Elias , Subramaniam Vignesh , Angelini Thomas , Von Roemeling Christina , Mitchell Duane , Rahman Maryam 
Published: November 2023

Abstract

INTRODUCTION
Intra-tumoral immunosuppression is a major cause of treatment failure for patients with glioblastoma (GBM). Our group has developed a proprietary vaccine that combines mRNA encapsulated in lipid nanoparticles with PEG hydrogel and a chemokine (CXCL9). This hydrogel-chemokine-mRNA (HCM) vaccine is delivered subcutaneously (SQ) and results in significant anti-tumor efficacy in syngeneic murine glioma models. The objective of this study was to evaluate the effects of the vaccine on the tumor microenvironment (TME).

METHODS
C57BL/6 mice underwent intracranial implantation of KR158-luc tumor cells and underwent SQ injection of the HCM vaccine using total tumor mRNA. Tumors were collected for analysis. Q-PCR and flow cytometry were done to evaluate the differential gene expression and CCR5 expression (receptor for CCL4) in the TME.

RESULTS
CCL4 was found to be upregulated in tumor-bearing animals treated with HCM vaccine using PCR. In a separate experiment, CCL4 blockade was given prior to HCM vaccination and this resulted in abrogation of the survival benefit of the vaccine. Next, flow cytometry was performed and microglia in the TME had the highest expression of the CCR5 receptor. CD4 T cells in the TME had significantly increased CCL4 expression after treatment with HCM vaccine.

CONCLUSION
The HCM vaccine results in significant anti-tumor efficacy in murine syngeneic murine glioma which is dependent on upregulation of CCL4 in the TME driven by CD4 T cells. The CCL4 exerts its effect through microglia expressing CCR5 in the TME. Further analysis of the effects of vaccination on microglia phenotype and function are underway.
CNSC-35. EVALUATING THE THERAPEUTIC POTENTIAL OF NOVEL NTRK AGONISTS AND ANTAGONISTS IN HIGH-RISK NEUROBLASTOMA
Authors: Johnson David , Schlichthaerle Thomas , Pattwell Siobhan , Baker David 
Published: November 2023

Abstract
Neuroblastoma is the most common extra-cranial tumor diagnosed in children within the first two years of their lives. Although low-risk and intermediate -risk neuroblastoma patients have a survival rate of 90-95%, high-risk neuroblastoma patients have a survival rate of approximately 50%. To improve the survival rate in high-risk patients, our group focuses on tropomyosin receptor kinases (TRKs), which are family of tyrosine kinases that have been heavily implicated in crucial developmental processes, such as differentiation, that are typically hijacked in cancer. Using de novo agonists specifically designed against three different neurotrophin receptors (TrkA, TrkB, TrkC), our group is investigating the fundamental biological role of TRK receptors in mediating tumorigenesis in neuroblastoma. Preliminary results show that our TrkA agonist not only increase both ERK and AKT activity but also causes a significant decrease in TrkA expression in several neuroblastoma cell lines which we hypothesize is due to constitutive activation of TrkA, leading to its internalization and degradation. Phenotypically, we observe that neuroblastoma cell line SK-N-SY5Y, which is typically used in differentiation studies, lose their neuroblast-like phenotype when treated with TrkA agonist, and begin to exhibit neurite outgrowth which may be indicative of differentiation-associated pathways being activated due to TrkA activation. Using a combination of de novo protein design, immunoblotting, RNA-sequencing, and in vivo studies to characterize the effect(s) TRK agonists have on neuroblastoma, we hope to assess whether targeting and modifying the activity of TrkA, and other Trk receptors such as TrkB and TrkC, holds new therapeutic promise for patients with high-risk neuroblastoma.
CNSC-36. INDOLENT INTRAVASCULAR LARGE B-CELL LYMPHOMA (IVLBCL) ORIGINALLY PRESENTING AS A STROKE MIMIC
Authors: Cabrera Nynoshka Bassatt , Philip Karan , Nasany Ruham Alshiekh 
Published: November 2023

Abstract

BACKGROUND
IVBCL is a rare subtype of extranodal diffuse large B-cell lymphoma, characterized by the growth of neoplastic cells in blood vessels with no other apparent extravascular mass, making diagnosis a challenge. It usually has an aggressive and fast-paced course; however, there is limited data regarding incidence due to its rarity.

CASE
A 73 year-old woman presented with progressive gait worsening a year prior to presentation to our institution. Her symptoms then developed to include left-sided hemiparesis with associated headaches, warranting a local emergency department visit. Brain magnetic resonance imaging (MRI) without contrast showed a Flair hyperintense lesion in the right MCA territory with restricted diffusion, assumed to be an ischemic stroke, and she was started on stroke prevention measures. The patient continued to decline, becoming wheelchair-bound and developing short-term memory loss, chronic headaches, and pseudobulbar affect. Repeat brain MRI without contrast five months later showed progression of the Flair hyperintensity to the left hemisphere with restricted diffusion. Brain MRI with contrast followed, revealing subtle enhancement. Vessel imaging was unremarkable, and cerebrospinal fluid (CSF) analysis was normal with negative cytology and flow cytometry, yet elevated beta-2-microglobulin at 3.25 mcg/mL. A year after symptoms onset, the patient presented to our Neuro-Oncology clinic. Repeat Brain MRI with contrast and spectroscopy showed progression on the left-sided lesion with persistent restriction diffusion and enhancement, prompting a biopsy. Pathology confirmed large B cell lymphoma. PET-CT body scan showed no evidence of systematic disease. The patient was treated with Rituximab, Methotrexate, Vincristine, and Procarbazine (RMVP) with complete response demonstrated by complete resolution of the diffusion restriction and symptoms improvement.

CONCLUSIONS
Although IVLBCL is known for being a fast progressive disease, we present a case of indolent course delaying diagnosis. Unexplained progressive neurological symptoms with restricted diffusion on MRI should prompt consideration for this diagnosis.
CNSC-41. DOES ISCHEMIC STROKE DRIVE BRAIN TUMOR PROGRESSION?
Authors: Ye Qi , Madamba Christine , Khatri Latha , Yang Yuhui , Rao Ganesh , Lee Hyun Kyoung 
Published: November 2023

Abstract
Glioblastoma multiforme is the most common and lethal primary brain tumor, with a 5-year survival rate of less than 5%. Its complex pathophysiology, highlighted by massive inflammatory responses, enhances tumor progression and impedes therapeutic interventions, leading to its dismal prognosis. Inflammatory responses are also a cardinal feature of brain injury and remarkably, clinical evidence from large-scale patient cohort studies indicates a link between glioma and cerebral ischemic stroke, where approximately 10% of ischemic stroke patients develop glioma. This observation suggests that brain injury may be a risk factor for the development of brain tumors; however, whether and how stroke occurrence promotes brain tumor progression is unknown. To address this knowledge gap, we employed a photothrombotic stroke mouse model in conjunction with established glioma models. In these models, we observed a significant increase in tumor cell proliferation and infiltration towards the infarct region and blood-brain barrier disruption. Intriguingly, spatial transcriptomic analysis in stroke-glioma models highlighted altered pH regulation in the microenvironment at the leading edge of tumor cells near stroke lesions. Further analysis revealed that the astrocytic pH regulator, Slc4a4, is significantly downregulated in the infiltrating tumor cells near infarct lesions, and that Slc4a4 inhibits tumor progression in our glioma models. Based on patient cohort studies that link glioma occurrence with cerebral ischemia and our new mouse model results, our data demonstrates that exposure to cortical ischemia-induced-hypoxia during tumorigenesis, promotes malignant glioma progression by altering the brain microenvironment via pH modulation. These conceptually innovative studies will integrate our new stroke-glioma models and advanced methodologies to investigate the stroke-glioma interaction via hypoxia and pH modulation, potentially identifying new therapy targets.