bluuebunny/crossref_metadata_2025_split huggingface dataset:
EXTH-05. ANTI-TUMOR IMMUNE RESPONSE OF ONCOMAGNETIC MONOTHERAPY IN GLIOBLASTOMA
Authors: Pandey Arvind , Hambarde Shashank , Baskin David S , Helekar Santosh A 
Published: November 2023

Abstract

BACKGROUND
Glioblastoma (GBM) is the most lethal primary malignant brain tumor with a median survival of 15–20 months. Concurrent temozolomide (TMZ) chemotherapy and radiation (XRT) remain the current standard of care (SOC) treatment for newly diagnosed GBM. The addition of tumor treating fields (TTFs) improves median survival for newly diagnosed GBM from 16 to 20.9 months. This modest improvement underscores the urgent need to identify a new treatment modality as a safe and effective therapy.

PURPOSE
The noninvasive Oncomagnetic device developed in our laboratory selectively kills glioblastoma (GBM) in vitro by generating the spinning oscillating magnetic field (sOMF) which disrupts electron transport chain, leading to a marked increase in reactive oxygen species (ROS) and consequently to cancer cell death. We studied the cellular and molecular effects of sOMF treatment on GBM cell lines and investigated the immune response to Oncomagnetic monotherapy (OMT) in a syngeneic mouse model.

RESULTS
sOMF significantly reduces cell proliferation and cell survival in vitro . It induces DNA damage and arrests cells in G1-phase of the cell cycle. Whole-body sOMF stimulation caused a substantial retardation of tumor growth and reduction of the contrast-enhanced tumor volume in 9.4T MRI scans. OMT showed significant increase in overall survival in treated mice. We also observed upregulated immune response indicated by RNA sequencing data obtained from sOMF-treated LN229 cells as well as in treated GBM mouse tumor sections by imaging mass cytometry analysis. The tSNE analysis of various immune clusters suggests significant increase in immune response by activating CD4+, CD8+, murine-macrophages and M1-macrophages located at tumor site in the treated group.

CONCLUSION
The obtained data indicate significant anti-tumor response by inhibiting cancer signaling pathways and an increased immune response. Our findings suggest unique mechanism of action for sOMF stimulation and provide a strong rationale for standalone OMT for GBM.
EXTH-13. ENHANCING INDUCED NEURAL STEM CELL-BASED TRAIL THERAPY FOR GLIOBLASTOMA THROUGH COMBINATION WITH THE NOVEL SENSITIZING AGENT TR-107
Authors: Thang Morrent , Mellows Clara , Mann Breanna , Kass Lauren , Daglish Sabrina , Fennell Emily , Mercer-Smith Alison , Valdivia Alain , Aponte-Collazo Lucas , Graves Lee M , Satterlee Andrew B , Hingtgen Shawn 
Published: November 2023

Abstract
Tumor-homing neural stem cell therapy (tNSC) is emerging as a promising treatment for aggressive cancers of the brain. Despite their success, developing tNSC therapies that maintain durable tumor suppression remains a challenge. Here, we report a new synergistic combination regimen where the novel agent TR107 augments induced NSC-TRAIL therapy (hiNeuroS-TRAIL) in models of the incurable brain cancer glioblastoma (GBM). We found that the combination of hiNeuroS-TRAIL and TR-107 synergistically upregulated caspase markers and restored the sensitivity to the intrinsic apoptotic pathway by significantly downregulating inhibitory pathways associated with chemoresistance and radioresistance in GBM. This combination regimen showed dramatic tumor suppression and enhancement of survival of mice bearing human xenografts of both solid GBM and established invasive GBM. The combination also synergistically suppressed tumor growth in low-passage patient derived GBM cells established with an ex vivo brain slice platform. These findings elucidate a novel combination regimen and suggest combination of these clinically relevant agents may represent a new therapeutic option with increased potency for GBM patients.
EXTH-26. 3D LIVE MICROSCOPY AND SINGLE CELL TRANSCRIPTOMIC TO DECIPHER MOLECULAR ACTORS INVOLVED IN GLIOBLASTOMA CELL INVASION IN HUMAN CEREBRAL ORGANOIDS
Authors: Verreault Maite , Akbar David , Cherchame Emeline , Galet Benjamin , Quissac Emie , Ravassard Philippe , Idbaih Ahmed 
Published: November 2023

Abstract
Glioblastomas are characterized by a highly invasive phenotype involving heterogeneous and dynamic molecular effectors. This process is one of the first causes of relapse following standard treatment. In vitro 2D cell migration assays do not recapitulate the biological and cellular microenvironment present in the human brain. Here, human induced pluripotent stem cells (hiPSC) -derived ventral forebrain organoids (hVFO) were used to assess the invasion phenotype of a panel of glioblastoma patient-derived cell lines (PDCLs) from mesenchymal, proneural and classical molecular subtypes. 3D live confocal microscopy allowed to characterize invasion phenotypes between PDCLs. A wide diversity of invasion phenotypes was observed which could not be explained by molecular subtypes. Single cell transcriptomic analysis was performed on a highly invasive PDCL following hVFO invasion, which permitted the identification of putative molecular candidates involved in invasion processes. Functional validation of druggable candidates is ongoing and will be presented.
EXTH-32. SYNERGISTIC EFFICACY OF Y BOX BINDING PROTEIN 1 (YBX1) INHIBITION COMBINED WITH CHEMOTHERAPY FOR THE TREATMENT OF MYC-AMPLIFIED MEDULLOBLASTOMA
Authors: Carney Stephen , Bonatto Christian , Guadarrama Guadalupe , Tailor Dhanir , Malhotra Sanjay , Evans Myron 
Published: November 2023

Abstract
Medulloblastoma is the most common pediatric brain tumor in children. Patients diagnosed with MYC-amplified group 3 (G3) have a dismal prognosis with a 5 year survival rate of &lt; 50%. Standard of care consists of maximal resection surgery followed by craniospinal irradiation and chemotherapy, but patients experience diminished quality of life from these extensive treatment regimens. Recent observations have shown that Y-box binding protein 1 (YBX1) is upregulated across human medulloblastoma subgroups compared to normal cerebellum. G3 patient tumors have the highest expression of YBX1, possibly due to an oncogenic feedback loop. We utilized an orthogonal pharmacogenetic approach to target YBX1. Knockdown/out of YBX1 significantly inhibits proliferation of G3 MB cells in vitro and in vivo. We next investigated the therapeutic potential of a novel YBX1 inhibitor, which displays single agent efficacy at decreasing the proliferation of medulloblastoma cell line derived xenografts (CDX). Since YBX1 targeting downregulated ABC transporter expression, we hypothesize that inhibition of YBX1 may sensitize medulloblastoma cells to chemotherapeutic agents. We performed drug synergy experiments combining YBX1 inhibition and commonly used standard of care chemotherapy. We identify that combining YBX1 inhibition sensitizes to both gemcitabine and vincristine in vitro and in vivo. We are currently evaluating this YBX1 inhibitor in an “anchor-probe” screen combining with all currently FDA approved drugs. Our findings impart an alluring prospect of targeting YBX1 in combination with chemotherapy, and possibly other compounds could improve patients’ outcomes.
EXTH-37. FUNCTIONAL GENOMICS IDENTIFIES THERAPEUTIC VULNERABILITIES OF GLIOMA SUBTYPES AND YAP/TAZ-ENRICHED TUMORS
Authors: Lin Wan-Hsin , Kosari Farhad , Smadbeck James , Barrett Michael , Feathers Ryan , Penheiter Alan , Lynch Jamie , Sotiriou Sotiris , Sadeghian Dorsay , Maruthi Vijaya Kadam , Johnson Sarah , Karagouga Giannoula , Harris Faye , Berry Taylor , McCune Alexa , Murphy Stephen , Kinsella Lindsey , Moniz-Garcia Diogo , Ensign Shannon Fortin , Yang Lin , Emanuel Angela , Salvatori Rebecca , Klein Janet Schaefer , Ida Cristine , Jentoft Mark , Salomao Marcela , Sherman Wendy , Porter Alyx , Rosenfeld Steven , Kizilbash Sani H , Jaeckle Kurt , Mrugala Maciej , Mansfield Aaron , Borad Mitesh , Bendok Bernard , Burns Terry , Quiñones-Hinojosa Alfredo , Cheville John , Vasmatzis George , Anastasiadis Panos 
Published: November 2023

Abstract
Sequencing efforts have identified key oncogenic drivers and transcriptomic subtypes of high-grade gliomas (HGGs), but this knowledge has not resulted in individualized therapy or improved patient outcomes. Here, we used a functional genomics approach combining integrated genomic/transcriptomic analyses with patient-derived 3D micro-cancers (mCancers) to rapidly identify individualized therapeutic vulnerabilities and determine predictive response biomarkers. 30 primary/recurrent HGGs, including 20 glioblastomas, 5 astrocytomas, and 5 oligodendrogliomas, were included for drug testing. mCancers recapitulated the structural and molecular alterations, cellularity, and heterogeneity, of parental patient tumors. A total of 119 single-agent drugs and 183 drug combinations were tested, while a pre-selected drug panel comprising 25 glioma-relevant treatment strategies was tested across all cases. In general, mCancer efficacy corresponded well to historical responses to previously tested agents (EGFR, HDAC inhibitors, etc.). Combined, strong efficacy (i.e. &gt;70% growth inhibition at Cmax) of single treatments targeting deregulated receptor tyrosine kinase (RTK), p53/apoptosis, cell cycle, DNA damage repair, IDH, or telomere maintainance pathways, was observed in 14 out of 30 cases. Surprisingly, transcriptional signatures, but not specific genetic alterations, were found to stratify drug responses. For example, mCancers enriched for the most aggressive mesenchymal (MES) and glycolytic/plurimetabolic (GPM) transcriptional subtypes exhibited stronger response to the BET inhibitor JQ1 (and other clinical BET inhibitors) and the DNA-PKcs/mTOR dual inhibitor CC-115. This therapeutic vulnerability was associated with enrichment of YAP/TAZ signaling, and the glioblastoma stem cell G-STEM signature. Notably, individual combination strategies were effective across tumors, with strong responses ranging from 38% to 77% of all tumors tested. Overall, this study underscores the value of functional genomics in identifying novel vulnerabilities of HGGs and associated response biomarkers. It also highlights the need for further clinical validation of several novel therapies and especially drug combination strategies with strong efficacy in the ex vivo setting.
EXTH-38. VELCRIN MOLECULAR GLUES INDUCE CELL DEATH IN GLIOBLASTOMAS WITH HIGH PDE3A AND SLFN12 EXPRESSION
Authors: Aquilanti Elisa , Goldoni Silvia , Baker Andrew , Kotynkova Kristina , Andersen Sawyer , Gao Galen , Cherniack Andrew , Lange Martin , Kopitz Charlotte , Lienau Philip , Lewis Timothy , Garrido Marine , Gradl Stefan , Seidel Henrik , Ligon Keith , Wen Patrick , Meyerson Matthew , Greulich Heidi 
Published: November 2023

Abstract
Velcrins are molecular glues that kill cells by inducing the formation of a protein complex between the RNase, SLFN12, and the phosphodiesterase, PDE3A. Formation of the complex activates SLFN12, which cleaves tRNALeu(TAA) and induces apoptosis. Velcrins such as the clinical investigational compound, BAY 2666605, were found to have activity across multiple solid tumor cell lines from the Cancer Cell Line Encyclopedia (CCLE), including glioblastoma cell lines. We therefore aimed to characterize velcrins as novel therapeutic agents in glioblastoma. We measured PDE3A and SLFN12 expression levels in commercially available glioblastoma cells as well as glioblastoma neurospheres from the Center for Patient Derived Models at Dana Farber Cancer Institute. We identified velcrin-sensitive glioblastoma cell lines and neurospheres, and determined that velcrin response is highly correlated with PDE3A expression. We also determined that sensitive cells exhibit a reduction in nascent polypeptide formation upon velcrin treatment, which is rescued by CRISPR-induced knockout of PDE3A. To assess velcrin efficacy in vivo, we measured central nervous system and plasma levels of the velcrin, BAY 2666605, and determined that it freely crosses the blood brain barrier. We also determined that twice daily dosing of BAY 2666605 elicits full tumor regression in an orthotopic glioblastoma xenograft model, with sustained complete responses after treatment withdrawal. Lastly, we demonstrated that the velcrins BAY 2666605 and BAY 2501293 induce tumor regression in biomarker-positive subcutaneous glioblastoma patient-derived xenograft models. In summary, our data demonstrates that velcrins have anti-tumor activity in preclinical models of glioblastoma, warranting further investigation as potential therapeutic agents.
EXTH-39. D2C7-CAR: A NOVEL, DUAL-SPECIFIC CHIMERIC ANTIGEN RECEPTOR T CELL WITH HIGH SPECIFICITY FOR EGFR AND EGFRVIII IMPROVES SURVIVAL IN EGFR/EGFRVIII GLIOBLASTOMA AND EGFR OVER-EXPRESSING MEDULLOBLASTOMA
Authors: Wilson Zach , Wilkinson Daniel , Ryan Katherine , Chandramohan Vidya , Bigner Darrell , Fecci Peter 
Published: November 2023

Abstract

BACKGROUND
GBM is the most common primary malignant brain tumor found in adults. Despite strenuous efforts at improving outcomes, overall survival remains dismal (15-20 months). D2C7-CAR is a dual specific CAR T cell that targets EGFR and EGFRvIII. We performed pre-clinical analysis of D2C7-CAR glioblastoma and other EGFR aberrant tumor models to assessed efficacy and safety.

METHODS
U87 and U87vIII glioblastoma and DAOY medulloblastoma cell lines were characterized by flow cytometry to evaluate for EGFR and EGFRvIII expression. Cytotoxicity assays were performed utilizing flow cytometry on serially diluted effector: target ratios of U87, U87vIII, and DAOY mixed with D2C7 CAR. U87 and U87vIII was orthotopically implanted into the frontal lobe and DAOY was orthotopically implanted into the frontal lobe and posterior fossa of NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ (NSG) mice. After tumor implantation, D2C7 CAR, vIII CAR, or Mock CAR was introduced within the tumor bed. Survival was measured and analyzed using the Log-rank test. Bioluminescence with IVIS imaging of CT2AVIII with luciferase was utilized to perform time point analysis of IC tumor response to treatment vs control. Toxicity against somatic tissue EGFR expression was assessed by in vitro cytotoxicity assay as described above.

RESULTS
EGFR was detected in U87, U87vIII, and DAOY on flow analysis. EGFRvIII was expressed only on U87vIII. D2C7 CAR demonstrated effective in vitro cytotoxicity against all three cell lines with &gt;90% cytotoxicity achieved at an effector: target ratio of 2.5:1. In vivo, D2C7 CAR significantly prolonged survival compared to treatment with mock and vIII CAR when tumor was implanted intracranially. Bioluminescence imaging demonstrated robust tumor response. D2C7 was not cytotoxic when co-cultured with EGFR expressing human keratinocytes.

CONCLUSION
D2C7-CAR demonstrates effective preclinical results both in vitro and in vivo. D2C7-CAR is not cytotoxic against human keratinocytes, suggesting it will be well tolerated in clinical trials.
EXTH-41. COMBINATION TREATMENT OF CALCIUM CHANNEL ANTAGONIST MIBEFRADIL ENHANCES THE EFFECT OF HYDROXYUREA AT THERAPEUTIC RANGES IN HIGH-GRADE MENINGIOMA IN VITRO
Authors: White Erik , Prabhu Michael , Thakkar Jigisha , Barton Kevin , Prabhu Vikram , Piedras-Renteria Erika 
Published: November 2023

Abstract
High-grade meningiomas (MNs), WHO Grade II- III, are highly aggressive brain tumors that are difficult to treat. Standard chemotherapy agents are, at best, moderately effective in treating high-grade MNs. There is great interest in developing combinatorial drug treatment regimens to enhance the effects of standard chemotherapy. Many cancer types, including brain tumors, have an increase in the expression of voltage-gated calcium channels (VGCCs). These channels are involved in the regulation of cell cycle, proliferation, and apoptosis, among other functions. FDA-approved VGCC antagonists nimodipine (NIMO) and mibefradil (MIB) target two different VGCCs, L- and T-type channels, and have been of great interest for their use in combination therapy in other cancers. We sought to determine the efficacy of chemotherapy agents tested at clinically relevant concentrations for the treatment of high-grade MNs alone or in combination with NIMO or MIB. We cultured CH-157MN and IOMM-Lee MN cells and assessed their cell survival, apoptosis, and proliferation in the presence of temozolomide, octreotide, sunitinib, or hydroxyurea (HU). We confirmed that HU (150 µM) was the most efficacious chemotherapy agent, decreasing cell viability at therapeutic ranges. Monotherapy treatment with 2 or 4 µM MIB significantly decreased cell viability in both cell lines, whereas 1 µM NIMO only affected IOMM-Lee cells. The combination of HU and MIB further decreased cell viability but only in the most aggressive cell line, IOMM-Lee, whereas NIMO did not enhance HU’s ability to decrease cell survival. Remarkably, we detect an enhancement of HU’s effect by MIB when both agents are used within therapeutic ranges, as reported by pharmacokinetic studies. Here we demonstrate for the first time that T-type calcium channels play an important role in MN survival. The combination of HU and MIB suggests their use could be a promising treatment for high-grade MN.
EXTH-48. PROTOPORPHYRIN IX LEVELS IN PATIENTS’ PLASMA, BLOOD, AND BRAIN TUMOR BY A VALIDATED LC-MS/MS METHOD
Authors: Knight William , Margaryan Tigran , Sanai Nader , Tovmasyan Artak 
Published: November 2023

Abstract

BACKGROUND
Protoporphyrin IX (PPIX) is an intermediate molecule in the heme biosynthesis pathway. Cancer cells, having a higher metabolic rate than normal cells, accumulate PPIX when an exogenous dose of its precursor, 5-aminolevulinic acid (5-ALA), is administered. 5-ALA is currently approved by the U.S. FDA for the visualization of high-grade gliomas (HGG) and fluorescence guided surgery. 5-ALA and PPIX are also central to experimental treatments of photodynamic and sonodynamic therapy for HGG patients. Accurate quantitation of PPIX in brain tumor, plasma, and blood is necessary to evaluate its pharmacokinetics and hence optimize its therapeutic benefit in the context of experimental therapies and tumor visualization.

METHODS
Plasma was used as a matrix for PPIX quantitation in plasma and brain homogenate. Brain homogenates (1:7) were prepared in 5 mM ammonium formate containing 0.2% formic acid. A separate plasma curve was used for blood quantitation. Before protein precipitation, blood and corresponding calibrators were diluted five times with water. PPIX was extracted from human plasma, blood, and brain homogenate samples using methanol containing PPIX-d6 (internal standard). Sample preparation was performed under low light conditions (&lt; 5 lux). Chromatographic separation of the analyte was achieved isocratically on Phenomenex Kinetex™ EVO C18 column, with a total run time of 3.5 min. Analyte detection was performed on Sciex QTRAP 6500+ MS/MS detector.

RESULTS
The method was validated for 1-2000 nmol/L range. Using plasma as a surrogate matrix, the maximum coefficient of variation for intra- and inter-day precision and accuracy were within acceptable ranges for all matrices.

CONCLUSIONS
A new rapid and sensitive LC-MS/MS method was successfully validated for the PPIX quantitation in human plasma, blood, and brain. It is currently used in a sonodynamic therapy clinical trial (NCT04559685) to evaluate PPIX pharmacokinetic profile in plasma and blood, and to determine levels in brain tumors of HGG patients.
EXTH-51. IDENTIFYING REGULATORS OF HETEROGENEITY IN DMGS USING SCREGCLUST
Authors: Yildirim Irem , Larsson Ida , Nelander Sven 
Published: November 2023

Abstract
Diffuse Midline Gliomas (DMGs) are pediatric brain tumors that arise in the pons, thalamus or the brainstem. DMGs present a pressing clinical problem since they cannot be surgically removed and respond poorly to radio- and chemotherapies. Like adult gliomas, DMGs present a high degree of intra-tumoral heterogeneity, with cells adopting different levels of differentiation similar to oligodendrocytes, astrocytes, precursor and mesenchymal cells. These different phenotypes possibly play distinct roles in tumor progression. Yet, we lack a good understanding of the underlying mechanisms of DMG heterogeneity. Here, we present a novel strategy to uncover regulator genes of DMG heterogeneity in a comprehensive and unbiased fashion, using an integration of machine learning with Cas9-based Perturb-seq. We first use a new data-driven modeling technique, termed single cell regulatory-driven clustering (scRegClust; Larsson et al., BioRxiv 2023) to uncover transcriptional modules, and their upstream transcriptional and kinase regulators. The goal of this analysis is to identify regulator genes that control cellular processes relevant to the disease, thereby enhancing our understanding of DMGs and uncover potential therapeutic targets. Applied to recently available single-cell data from 90 DMG patients, scRegClust revealed 160 regulators of meta-modules including oligodendrocyte-like, oligodendrocyte-progenitor-like, astrocyte-like and mesenchymal like cells. To validate the importance of these regulators, we are establishing a Perturb-seq experimental pipeline by combining pooled CRISPR knock-out and single cell RNA sequencing in patient-derived DMG cell lines. By perturbing the candidate regulators both in vitro and in vivo we aim to evaluate their impact on DMG tumorigenicity. This comprehensive strategy will ultimately increase our understanding of the molecular processes in DMGs and present the functional significance of these regulators and their involvement in disease progression.
EXTH-66. SINGLE-CELL SPATIOTEMPORAL GENOMICS REVEALS CLONAL EVOLUTION AND THERAPEUTIC TARGET IN RECURRENT DISSEMINATED MEDULLOBLASTOMA
Authors: Liu Hailong , Li Jiankang , Wang Ziwei , Liu Fei , Qiu Xiaoguang , Jiang Tao 
Published: November 2023

Abstract
Despite the cellular heterogeneity observed in single-cell studies of medulloblastoma, limited knowledge exists regarding the genetic features and spatiotemporal states of specific cell populations following tumor relapse and dissemination, leading to a lack of effective treatment strategies. In this study, we conducted single-cell transcriptomic, chromatin accessibility, and spatial transcriptomic analyses on 15 primary and recurrent Group 3 medulloblastomas, along with two PDX models (including a lung metastasis model). Subsequently, we deconvoluted our findings with our RNA-seq cohort to further validate cell cluster-specific gene expression associated with relapse and its prognostic significance. We analyzed malignant cells, including cancer stem cells (MB-CSCs), proliferating cells, and differentiated cell populations, and examined gene expression features closely associated with clinical prognosis. To elucidate the origin and maturation process of these malignant cells accurately, we compared tumor cell profiles with early human cerebellar cell-types. Furthermore, we described the spatiotemporal transitions from MB-CSCs to terminal states, with a particular emphasis on the extensive spatial heterogeneity within the tumor during the processes of primary, local relapse, and dissemination. Through computational non-negative matrix factorization (cNMF) analysis, we identified a group of tumor cells in recurrent Group 3 medulloblastoma with high cellular plasticity (HCP), demonstrating strong stemness and proliferative capabilities, as well as the ability to differentiate into multiple functional tumor cell subgroups. This cell population exhibited elevated expression of PTPRZ1, which phosphorylates downstream molecules to promote tumor progression. Through single-cell transcriptomic and chromatin accessibility analyses, we validated the expression of PTPRZ1 in human samples, PDX samples, and transgenic mouse samples. In vitro and in vivo inhibition of PTPRZ1 function using small molecule inhibitors effectively suppressed tumor proliferation and metastatic activity. By employing single-cell spatiotemporal genomics, we elucidated the evolutionary states and subclonal events of primary and recurrent medulloblastoma, and identified PTPRZ1 as a target for effectively inhibiting tumor progression.