bluuebunny/crossref_metadata_2025_split huggingface dataset:
BIOS-03. COPY NUMBER VARIATION (CNV) AND CLINICAL OUTCOMES IN IDH-WILDTYPE VERSUS IDH-MUTANT GLIOMA
Authors: Chow Jocelyn , Bray David , Rupji Manali , Mannam Sai , Greenberg Ross , Dansby Kamaria , Neill Stewart , Switchenko Jeffrey , Bojanowski-Hoang Kimberly 
Published: November 2023

Abstract
Genomic classification of gliomas has the potential for improved prognostication and treatment guidance. However, much work remains to elucidate the full potential of genomics in glioma characterization. IDH mutant gliomas generally carry an improved survival compared to their wild-type counterparts, but their clinical course is significantly more variable and challenging to predict. The goal of this study is to characterize tumor genetic/genomic parameters associated with progression-free survival (PFS) and overall survival (OS) of both IDH-wildtype and IDH-mutant gliomas and compare the two subtypes for further stratification. We collected data for 203 patients diagnosed with IDH-wildtype gliomas (WHO Grade IV) and 88 patients with IDH-mutant gliomas (WHO Grade II-IV) from the Emory Healthcare system. Microarray single nucleotide polymorphism-copy number analysis was performed to detect total CNVs which are associated with tumor mutational burden. We analyzed total CNV based on the median, quartiles, and optimal cut points via the ideal cutpoint calculator, Cutoff Finder. We then estimated the correlation between % total CNV, PFS, and OS using the Pearson correlation coefficient. For IDH-wildtype gliomas, the mean CNV was 18.69 (standard deviation (SD): 9.62), and the median was 16.00 (IQR: 1-57). The optimal cutoff was defined as 39 for PFS analysis and 20.5 for OS analysis. For IDH-mutant gliomas, the mean CNV was 12.8 (SD: 11.36), and the median was 8.5 (IQR: 5 – 17.5). The optimal cutoff was defined as 10.5 for OS analysis and 7.5 for PFS analysis. Overall, higher CNV was associated with lower PFS and OS in both groups. However, the results were only statistically significant for OS at the optimal cutoff (20.5) for IDH-wildtype gliomas (p-value = 0.0379), and for PFS at the optimal cutoff (7.5) for IDH-mutant gliomas (p-value = 0.0420). These findings suggest that CNV may be useful as a potential prognosis factor for both tumor subtypes in different contexts.
CNSC-02. GLUTAMATERGIC SYNAPTIC INPUT DRIVES BRAIN METASTASIS OF BREAST CANCER AND MELANOMA
Authors: Karreman Matthia , Venkataramani Varun , Nguyen Linh C , Hebach Nils , Tehranian Cedric , Mayer Chanté , Meyer Lasse , Mughal Sadaf , Geckeler Lukas , Westphal Dana , Breckwoldt Michael , Wick Wolfgang , Kuner Thomas , Winkler Frank 
Published: November 2023

Abstract
The nervous system is implicated in pathology of both cranial and extracranial cancers. In glioblastoma, direct excitatory glutamatergic synapses between neurons and cancer cells were discovered. Importantly, these neuron-cancer contacts drive glioblastoma proliferation and invasion. However, such synapses have not yet been documented in other types of brain cancer. In the context of brain metastases, indirect, peri-synaptic contacts between breast cancer cells and neurons were observed, which promote brain metastatic growth through glutamatergic signaling via NMDA receptors on the neoplastic cells. Recently, two studies have demonstrated that neuronal activity supports the growth of both the primary tumor and brain metastases from neuroendocrine carcinoma small cell lung cancer. In the work presented here, we demonstrate direct neuron-cancer synapses in early-stage brain metastases originating from breast cancer and melanoma. These synapses exhibited the typical structural features observed in synaptic connections and induced postsynaptic currents in the cancer cells through the activation of AMPA subtype glutamate receptors. Importantly, genetic and pharmacological perturbation of these receptors reduces the number of brain metastases and the overall metastatic burden in preclinical models of breast cancer and melanoma. These results uncover a previously unknown form of direct communication between neurons and brain-metastatic breast cancer and melanoma tumor cells. This neuronal-tumor synaptic interaction demonstrates the significance of the neuronal microenvironment in the early stages of the brain metastatic cascade. Furthermore, it unveils a potential therapeutic vulnerability associated with the neuronal microenvironment, suggesting that targeting the synaptic communication between neurons and cancer cells could be a promising strategy to impede the progression of brain metastases.
CNSC-13. NEURODEVELOPMENTAL TRANSCRIPTION FACTORS PROMOTE PROLIFERATION, REGULATE CELL TYPE, AND PLAY OPPOSING ROLES IN CELLULAR MIGRATION IN GLIOBLASTOMA
Authors: Myers Bianca , Brayer Kathryn , Paez-Beltran Luis , Vue Tou Yia 
Published: November 2023

Abstract
Glioblastomas (GBM) make up ~50% of primary brain tumors and prognosis has not improved over the last 30 years. Despite high inter- and intratumoral heterogeneity, basic-helix-loop-helix (bHLH) transcription factors, ASCL1 and OLIG2, are present in the majority of tumors. Previously, we showed in patient-derived GBM xenograft (PDX-GBM) that ASCL1 binds to promoter and enhancer regions of cell cycle genes, as well as neurodevelopmental transcription factors including OLIG2. Similarly, we showed that OLIG2 binding overlaps with the majority (~90%) of ASCL1 binding sites, including at promoter and/or enhancer regions of ASCL1 and OLIG1/2 loci, illustrating their potential redundant and/or feed-forward function in GBM. It has been proposed that ASCL1 and OLIG2 contribute to the neural stem cell-like properties of tumor cells, which may promote tumor growth and progression but also the treatment resistivity and high recurrence rate of GBMs in patients. Using an immune competent glioma mouse model, we are able to efficiently induce tumors from glial progenitors surrounding the lateral ventricle while altering the levels of ASCL1 and OLIG2 to assess their combinatory roles in GBM progression. Remarkably, we found that loss of both Ascl1 and Olig2 prevents tumor formation in 80% of mice, whereas the loss of only Ascl1 resulted in reduced cellular migration from the tumor bulk while the loss of Olig2 promotes a highly migratory phenotype. Conversely, elevating the levels of Ascl1increased both tumor cell proliferation and migration similar to the loss of OLIG2. Using single cell RNA-sequencing, we found that tumor cells which express high levels of Ascl1 exhibit neural stem cell/astrocytic gene signatures, which supports ASCL1’s role as a marker of glioma-stem-cells. Collectively, these findings illustrate the role of ASCL1 and OLIG2 in regulating GBM initiation, proliferation, and migration where ASCL1 may directly be responsible for the highly invasive and proliferative phenotype of GBMs.
CNSC-17. WHOLE-BRAIN SPECTRAL CHANGE IN GLIOBLASTOMA PATIENTS: ASSOCIATIONS WITH CLINICAL COMORBIDITIES AND OVERALL SURVIVAL
Authors: Park Ki Yun , Snyder Abraham , Olufawo Michael , Trevino Gabriel , Luckett Patrick , Lamichhane Bidhan , Xie Tao , Lee John , Shimony Joshua , Leuthardt Eric 
Published: November 2023

Abstract
Glioblastoma, a highly aggressive form of brain tumor, is a brain-wide disease. We evaluated the impact of tumor burden on whole brain resting-state functional magnetic resonance imaging (rs-fMRI) activity. Specifically, we analyzed rs-fMRI signals in the temporal frequency domain in terms of the power-law exponent and fractional amplitude of low-frequency fluctuations (fALFF). We contrasted 189 patients with newly-diagnosed glioblastoma versus 189 age-matched reference participants. The patient and reference datasets were matched for age and head motion. The principal finding was markedly flatter spectra and reduced grey matter fALFF in the patients as compared to the reference dataset. We posit that the whole-brain spectral change is attributable to global dysregulation of excitatory and inhibitory balance and metabolic demand in the tumor-bearing brain. Additionally, we observed that clinical comorbidities, in particular, seizures, and MGMT promoter methylation, were associated with flatter spectra. Notably, the degree of change in spectra was predictive of overall survival. Our findings suggest that frequency domain analysis of rs-fMRI activity provides prognostic information in glioblastoma patients and offers a means of noninvasively studying the effects of glioblastoma on the whole brain.
CNSC-20. MGMT PROMOTER METHYLATED HIGH GRADE GLIOMA WITH DISTANT RECURRENCE AND STABLE ORIGINAL TUMOR SITE: CASE SERIES
Authors: Jani Ronak , Lee Jonathan , Jusue-Torres Ignacio , Germanwala Anand , Borys Ewa , Solanki Abhishek , Mallik Atul , Barton Kevin , Prabhu Vikram 
Published: November 2023

Abstract
Recurrence pattern in high grade glioma is classified as local and distant recurrence based on distance from original resection cavity and radiation field. We report the first series of three cases of O6-methylguanine-DNA methyltransferase (MGMT) promoter methylated high grade glioma with distant recurrence without local recurrence throughout the disease course. Patient 1: 65 year-old female with WHO grade 4 glioblastoma, isocitrate dehydrogenase enzyme (IDH) wild type (WT), MGMT methylated. She underwent gross total resection followed by Stupp protocol. Postoperative ischemic volume was &lt; 1 ml. Distant recurrence occurred 4 months after completion of Stupp protocol. Patient 2: 55 year-old male with WHO grade 4 glioblastoma, IDH wild type, MGMT methylated. He underwent gross total resection followed by Stupp protocol. Postoperative ischemic volume was 18 ml. Distant recurrence occurred 5 months after completion of Stupp protocol. Patient 3: 31 year-old male with WHO grade 4 astrocytoma, IDH mutant, MGMT promoter methylated. He underwent gross total resection followed by Stupp protocol. Postoperative ischemic volume was 2 ml. Distant recurrence occurred 10 months after completion of Stupp protocol. Distant recurrence is more common in MGMT promoter methylated tumors. All 3 patients in our case series had poor outcomes after distant recurrence without local recurrence at the original tumor site. This observation indicates good local control in MGMT promoter methylated high grade glioma with current standard treatment. For one patient, next generation sequencing (NGS) was available for both original and recurrent tumor and did not reveal any major differences in the genetics of original tumor and distant recurrent tumor other than temozolomide induced high tumor mutational burden in the distant recurrent tumor. Understanding risk factors for distant recurrence in MGMT promoter methylated high grade gliomas and investigating correlations between recurrences will help plan therapeutic strategies to prevent distant recurrence and improve outcomes.
CNSC-26. GLIOBLASTOMA-NEURONAL CIRCUIT INTEGRATION IS MODULATED BY INTERLEUKIN-6
Authors: Daniel Andy , Krishna Saritha , Hervey-Jumper Shawn 
Published: November 2023

Abstract
The pleiotropic cytokine interleukin-6 (IL-6) is known to be involved in both pro- and anti-inflammatory signaling cascades. In glioblastoma studies using animal and human models, IL-6 promotes immunosuppression and tumor progression and is negatively associated with survival. Intriguingly, IL-6 also contributes to increased synaptogenesis during development and following focal brain injury. Glioblastoma remodeling of neuronal circuits influences patient survival; therefore, it is possible that IL-6 has mechanistic significance. Here, we investigated IL-6 as a driver of activity-dependent glioblastoma proliferation using patient-derived xenograft (PDX) mouse and human glioblastoma models. We assessed neuronal activity by microelectrode arrays and in vitro calcium imaging using weighted mean firing rate (WMFR), network burst frequency (NBF), and synchrony index. Next, we used bulk and single-cell RNA sequencing on 13,731 cells from ten tumors including pair-matched samples to identify differentially expressed genes in intratumoral regions with elevated functional connectivity and found IL6 to be highly upregulated. Mouse embryonic cortical neurons and cerebral organoids co-cultured with primary patient-derived glioblastoma cells demonstrated concentration-dependent neuronal hyperexcitability (increased WMFR and NBF) in IL-6-overexpressing conditions compared to the neuron-only condition. Pharmacological inhibition using the humanized IL-6 receptor antibody tocilizumab reduced network synchrony across models. These findings suggest that IL-6-induced glioma-neuronal hyperexcitability may be inhibited by the FDA-approved tocilizumab, thereby providing preclinical support for its use to treat activity-dependent mechanisms of glioblastoma proliferation. Future studies are needed to uncover mechanisms and clinical efficacy.
CNSC-28. CELLULAR AND FUNCTIONAL REMODELING OF HUMAN CEREBRAL ORGANOIDS BY GLIOBLASTOMA STEM-LIKE CELLS
Authors: Singh Sanjay , Milutinovic Bojana , Bronk Lawrence , Bronk Julianna , Shepherd Andrew , Grosshans David , Phillips Lynette , Lang Frederick 
Published: November 2023

Abstract
The burgeoning field of cancer neuroscience focuses on deciphering the role of normal neural cells in brain tumor growth. Until recently, representation of normal human neural cells in brain tumor model systems was lacking. By utilizing human induced-pluripotent stem cells derived cerebral organoids (COs) co-cultured with glioblastoma stem-like cells (RFP-luciferase tagged MDA-GSCs, n = 3 representing each glioblastoma molecular sub-type), we investigated the effects of GSCs on CO-derived neural cells and their activity. COs and CO+MDA-GSCs were subjected to single-cell RNA-sequencing (scRNA-seq). As per typical micro-anatomy of COs, neural stem/progenitor cells are interiorly distributed whereas differentiated neurons are positioned on the surfaces, enabling measurement of neuronal action potential on surfaces of COs by micro-electrode arrays (MEA). The scRNA-seq data from CO+MDA-GSC samples were subset into CO-derived (luciferase-ve) and GSCs-derived (luciferase+ve). Compared with COs, co-cultured samples had significantly higher percentage of non-telencephalon neural progenitor cells (ntNPCs) (CO_vs._CO+MDA-GSC(luciferase-ve): 15.6% vs. 47.2%-63.4%) while the percentages of cortical NPC (cNPCs) and intermediate progenitors (IPs) was lower (CO_vs._CO+MDA-GSC(luciferase-ve): 39.2% vs. 12.0%-20.5%). These alterations in NPC/IPs abundance were accompanied by decreased proportions of cortical excitatory neurons (CO_vs._CO+MDA-GSC(Luciferase-ve): 33.2% vs. 7.9%-23.4%). Among luciferase+ve MDA-GSCs-derived cells in co-culture samples, mesenchymal MDA-GSCs had higher abundance of ntNPCs versus cNPCs (30.4% versus 63.6%) whereas, among classical and proneural MDA-GSCs ntNPCs were 11.45-22.8 times higher. Interestingly, 14.9% of proneural MDA-GSCs derived cells displayed inhibitory neuron signatures. After 3 weeks, the mean firing rate measured by MEA was significantly lower in co-cultures compared to COs (CO_vs._CO+MDA-GSC: 0.052 Hz vs. 0.0081 Hz p-value 0.000219), suggesting functional remodeling. Our results show that cellular remodeling of normal cells resulted in progenitor-like cell-state whereas that of MDA-GSCs varied across molecular sub-type. These results suggest interactions between normal and tumor cells can potentially be leveraged to manage brain tumor growth and its impact on normal brain.
CNSC-29. NKCC1 SIGNALING IN GLIOBLASTOMA REGULATES NEURONAL HYPEREXCITABILITY THROUGH GABAERGIC TONE
Authors: Krishna Saritha , Daniel Andy , Ambati Vardhaan , Seibert Clara , Hervey-Jumper Shawn 
Published: November 2023

Abstract
Over 90% of patients with glioma experience tumor-associated epilepsy, however first-line treatment fails to control seizures in most patients. Thus, there is a critical need to identify novel drivers of glioblastoma-induced neuronal hyperexcitability. We therefore used high-density electrode arrays to record local field potentials in vivo from gliomas. We then developed cerebral organoid and mouse models using primary glioblastoma cells from patients and neurons derived from induced pluripotent stem cells. Single-cell RNA sequencing (13,730 cells analyzed) in this system identified genes elevated in glioma-intrinsic neurons, including the sodium-potassium-chloride co-transporter 1 (NKCC1), which mediates chloride (Cl-) influx into cells. This elevated NKCC1 expression and subsequent increase of intracellular Cl- sets the reversal potential of GABAAR-mediated currents promoting depolarizing excitatory GABAergic responses. Electrophysiological analysis of glioma-neuron co-cultures using multi-electrode array and live-cell calcium imaging demonstrated increased network burst synchrony in the presence of NKCC1-high expressing tumor cells. Single-nucleus sequencing (54,000 cells analyzed) of embryonic neurons in co-culture with GBM cells further confirmed the elevated expression of circuit assembly genes including neuronal NKCC1. Live-cell imaging of iPSC-induced neuron organoids co-cultured with NKCC1-high-and low-GBM cells revealed increased migration and integration of NKCC1-elevated tumor cells. Mechanistic and functional studies validating therapeutic vulnerabilities to NKCC1 silencing by shRNA knockdown and by the FDA-approved diuretic drug, bumetanide was performed in vitro. The reduction in neuronal synchrony induced by NKCC1 downregulation correlated with a decrease in extracellular GABA and glutamate, suggesting a strong association between excitatory GABAergic and glutamate signaling with neuronal hypersynchrony in glioblastoma. Patient-derived xenograft in vivo experiments evaluated the effect of NKCC1 on tumor growth and progression and NKCC1-high GBM cells exhibited greater tumor burden compared to control mice. Collectively, these findings reveal a novel mechanism driving neuronal hyperactivity in glioblastoma and identifies potential therapeutic vulnerabilities for the treatment of glioma-associated epilepsy.
CNSC-32. SIMULTANEOUS INVESTIGATION OF TUMOR CELL BEHAVIOR AND CONNECTIVITY WITH CORRELATIVE IN VIVO TWO-PHOTON AND EX VIVO EXPANSION MICROSCOPY
Authors: Reyhan Ekin , Wick Wolfgang , Venkataramani Varun 
Published: November 2023

Abstract
Glioblastomas are the most aggressive primary brain tumors, characterized by whole-brain colonization, high therapeutic resistance, and inevitable recurrence. It has previously been shown that glioblastoma cells can form functionally gap-junction connected tumor cell networks with other tumor cells and/or astrocytes, which play a crucial role in tumor progression and treatment response. Furthermore, there is increasing evidence that synaptic neuron-glioma networks promote tumor growth. However, methodologies to investigate the direct link between synaptic, astrocytic and tumor cell connectivity together with tumor cell behavior including invasion, proliferation and therapeutic resistance are yet lacking. We aimed to characterize neuron-tumor and tumor-tumor/astrocyte cell interactions on a single cell level by using correlative in vivo two-photon and ex vivo expansion microscopy with near synaptic-resolution. We studied glioblastoma cells with intravital two-photon microscopy using patient-derived glioblastoma mouse models and the fluorescent functional imaging dye Sulforhodamine 101 allowing to investigate intratumoral and astrocytic connectivity over an extended period up to weeks. Subsequently, these functional tumor cell subpopulations could be directly correlated ex vivo to identify neuron-glioma synaptic connectivity. We utilized machine learning based segmentation and a semi-automated analysis pipeline to explore the connection of different glioblastoma morphological and behavioral subtypes to direct and indirect neuronal input in multiple xenograft models. With this new correlative method, we were able to simultaneously evaluate tumor cell behavior, synaptic and tumor-tumor/astrocyte connections on a single cell level. In addition, we demonstrated that this pipeline can be used for patient samples, revealing its clinical-translational potential for cancer neuroscience. In summary, we have established a new correlative technology that interlinks two key aspects of brain cancer neuroscience: cancer cell behavior and brain tumor network connectivity. This methodology promises a more thorough understanding of glioblastoma biology, facilitating the discovery of cancer biology, including the role of brain tumor networks in therapeutic resistance.
CNSC-33. MOLECULAR AND FUNCTIONAL DRIVERS OF ACTIVITY DEPENDENT GLIOBLASTOMA PROLIFERATION
Authors: Negussie Mikias , Krishna Saritha , Wei Ying , Aabedi Alexander , Ambati Vardhaan , Daniel Andy , Lu Katie , Hervey-Jumper Shawn 
Published: November 2023

Abstract
Glioblastoma, the most common primary brain tumor in adults, is a major cause of neurological morbidity and mortality with no effective therapies. Its proliferation and invasion are regulated by direct and paracrine-mediated neuronal activity. In this study, we uncover molecular targets and protein-protein signaling driving activity dependent proliferation. To identify candidate molecular pathways, we used high-density electrode arrays in vivo to record human local field potentials. Single-cell RNA sequencing identified Netrin-G1 (NTNG1) and thrombospondin-1 (TSP1) elevation in glioblastoma clonal population that proliferates in response to the presence of neurons. The amino acid sequence of NTNG1 and the TSR1 domain of TSP1 were utilized to predict the 3D interaction surface of NTNG1 and TSP1. Compared to structure predictions of NTNG1 and its known binding partner NGL1, NTNG1 and TSP1 complex predictions showed agreement between machine learning predicted models and lower predicted aligned error in interdomain regions of the complex, suggesting higher confidence in the relative position of NTNG1-TSP1 as compared to NTNG1-NGL1. We performed 45 protein structure predictions and two molecular dynamics simulations of mutant and WT TSP1 in complex with NTNG1. Each simulation box consisted of &gt;263,000 atoms, each run for 50 million 2 femtosecond timesteps for a total simulation time of 200 ns. These calculations confirmed a stable complex in the WT condition and significant conformational change in the R46A condition, emphasizing the importance of this residue in mediating NTNG1-TSP1 binding. Computational affinity models between NTNG1 and TSP1 were validated by pull-down assays and immunofluorescence labelling using cerebral organoid and human glioma-neuronal coculture models. Finally, we design small molecule and fusion-protein inhibitors disrupting this interaction. Here we advance the development of targeted precision-medicine therapies to treat glioblastoma proliferation through activity-dependent mechanisms.