bluuebunny/crossref_metadata_2025_split huggingface dataset:
TMET-08. RADIATION-INDUCED SLC25A22 CONTRIBUTES TO GLIOBLASTOMA RADIORESISTANCE ACQUISITION THROUGH REMODELING GLUTAMATE METABOLISM
Authors: Kim Byeongsoo , Lee Haksoo , Kim Dahye , Park Junhyeong , Park Sujin , Kang JiHoon , Youn HyeSook , Youn BuHyun 
Published: November 2024

Abstract
Glioblastoma Multiforme (GBM), a malignant primary brain tumor, is treated by surgical resection followed by chemo- and radiotherapy. Nevertheless, most GBM patients show dismal prognosis due to the radioresistance acquisition of GBM cells via metabolic rewiring. Therefore, it is urgently required to discover how metabolic rewiring attributes to GBM radioresistance, and its targeting strategies. To identify GBM radioresistance driver genes, we previously established radioresistance GBM cells (RGCs) via repetitive in vivo selection, followed by mRNA sequencing, and selected candidate genes that are altered in RGCs (fold change&gt;2 or &lt;0.5, p-value&lt;0.05) and also related with GBM patients’ prognosis. Here, we focused on amino acid transmembrane transporter (Gene Ontology: 0003333) and found that SLC25A22 was the most increased in RGCs. SLC25A22 exhibits uni-directional properties, exporting glutamate to cytosol, resulting in cytosolic glutamate accumulation in RGCs. Using 13C glutamine isotope tracing analysis following mitochondrial fractionation, we quantified the mitochondrial metabolic flux of glutamine. Despite decreased 13C glutamate efflux from RGCs mitochondria after genetic inhibition of SLC25A22, glutamine metabolites (a-ketoglutarate, succinate, malate, fumarate) remained constant. Cytosolic glutamate, as a substrate, is incorporated into various biosynthetic pathways, especially glutathione (GSH) and proline synthesis pathways in radioresistant GBM cells. GSH protects GBM cells by scavenging radiation-induced reactive oxygen species. Whereas, proline, a rate-limiting substrate for collagen biosynthesis, leads GBM cells to show an invasiveness phenotype via extracellular matrix remodeling. Genetic inhibition of SLC25A22 using short hairpin RNA (shRNA) or microRNA-184 mimic suppresses RGCs radioresistance and aggressiveness. Additionally, intranasal administration of microRNA-184 mimic prolonged the survival (median survival: 26 days after irradiation) of GBM-bearing mice, compared with non-target control (median survival: 16 days after irradiation). Together, our study demonstrates that SLC25A22 upregulation confers GBM radioresistance by inducing cytosolic glutamate-driven biosynthesis and suggests SLC25A22 as a therapeutic target to overcome GBM radioresistance.
TMET-11. IMPACT OF METABOLIC RISK FACTORS ON SURVIVAL IN GLIOBLASTOMA IDH-WILD TYPE
Authors: Paul Aboubechara John , Aboud Orwa 
Published: November 2024

Abstract
Altered cellular metabolism is a hallmark of cancer. Systemic metabolic dysregulation has been associated with the pathogenesis of cancer, including glioblastoma. In particular, the metabolic syndrome has been found to increase the risk of developing various systemic cancers, but it is not known how often the metabolic syndrome occurs in patients with glioblastoma or how it affects their clinical outcomes. This study retrospectively investigates the prevalence and impact of metabolic syndrome, and its component risk factors, on survival in patients with glioblastoma IDH-wild type. Interim analysis includes results from 73 patients with anticipation of over 100 patients who received treatment at UC Davis between 2018-2024. Metabolic syndrome prevalence prior to diagnosis was 41% (30/73), higher than the prevalence of 33% in the general population. Patients with metabolic syndrome showed a trend towards reduced overall survival. A significant dose-response association was found between the number of metabolic risk factors and overall survival (p=0.03). Hyperglycemia demonstrated worsened survival (p=0.04), aligning with prior studies. Obesity, hypertension, and dyslipidemia were not significantly associated with survival. These findings highlight the therapeutic potential for targeting systemic metabolic dysregulation, and hyperglycemia in particular, in patients with glioblastoma.
TMET-15. INVESTIGATING THE IL4I1-AHR AXIS IN GLIOBLASTOMA METABOLISM
Authors: Sayeeram Deepak , Holfelder Pauline , Prentzell Mirja T , Immler Lorena , Karabogdan Ivana , Hau Peter , Trump Saskia , Opitz Christiane A 
Published: November 2024

Abstract
Glioblastoma (GB) is the most frequent and malignant form of primary brain tumors in adults. Despite multi-modal therapy consisting of surgery, radio- and chemotherapy, tumors recur and overall survival remains poor. Previously, we identified that besides the classical tryptophan-catabolizing enzyme tryptophan-2,3-dioxygenase (TDO2), the L-amino acid oxidase interleukin-4-induced 1 (IL4I1) is able to activate the transcription factor aryl hydrocarbon receptor (AHR) via production of downstream metabolites. Activation of the AHR in GB may promote tumor progression e.g. by inhibiting anti-tumor immune responses. In this study, we aim to elucidate further the specific effects of the metabolic enzyme IL4I1 and its metabolites on AHR activation in GB. Further, we set out to identify and validate novel AHR target genes downstream of IL4I1. Harnessing the IL4I1-AHR axis might lead to the development of novel therapy strategies helping to overcome resistance in GB in the future.
TMET-28. RECIPROCAL LINKS BETWEEN METHIONINE METABOLISM, DNA REPAIR AND THERAPY RESISTANCE IN GLIOBLASTOMA
Authors: Korimerla Navyateja , Wilder-Romans Kari , Xu Jie , Haq Isra , Zhou Weihua , Kalev Peter , Qi Nathan , Evans Charles , Kachman Maureen , Zhao Zitong , Lin Angelica , Scott Andrew J , O’Brien Alexandra , Kothari Ayesha , Palavalasa Sravya , Peterson Erik , Hyer Marc L , Marjon Katya , Lyssiotis Costas A , Sleger Taryn , Wahl Daniel R 
Published: November 2024

Abstract
Glioblastoma (GBM) is uniformly lethal due to profound treatment resistance. Altered cellular metabolism is a key mediator of GBM treatment resistance. Uptake of the essential sulfur-containing amino acid methionine is drastically elevated in GBMs compared to normal cells, however, it is not known how this methionine is utilized or whether it relates to GBM treatment resistance.Here, we find that radiation acutely increases the levels of methionine-related metabolites in a variety of treatment-resistant GBM models. Stable isotope tracing studies further revealed that radiation acutely activates methionine to S-adenosyl methionine (SAM) conversion through an active signaling event mediated by the kinases of the DNA damage response. In vivo tumor SAM synthesis increases after radiation, while normal brain SAM production remains unchanged, indicating a tumor-specific metabolic alteration to radiation. Pharmacological and dietary strategies to block methionine to SAM conversion slowed DNA damage response and increased cell death following radiation in vitro. Mechanistically, these effects are due to depletion of DNA repair proteins and are reversed by SAM supplementation. These effects are selective to GBMs lacking the methionine salvage enzyme methylthioadenosine phosphorylase. Pharmacological inhibition of SAM synthesis hindered tumor growth in flank and orthotopic in vivo GBM models when combined with radiation. By contrast, methionine depletion does not reduce tumor SAM levels and fails to radiosensitize intracranial models, indicating depleting SAM, as opposed to simply lowering methionine, is critical for hindering tumor growth in intracranial models of GBM. These results highlight a new signaling link between DNA damage and SAM synthesis and define the metabolic fates of methionine in GBM in vivo. Inhibiting radiation-induced SAM synthesis slows DNA repair and augments radiation efficacy in GBM. Using MAT2A inhibitors to deplete SAM may selectively overcome treatment resistance in GBMs with defective methionine salvage while sparing normal brain.
TMIC-16. SPECIFIC TARGETING OF THE MRNA EXPRESSION OF TGFB2 LIGAND TO POTENTIALLY ENHANCE IMMUNE THERAPIES IN LOW-GRADE GLIOMAS
Authors: Qazi Sanjive , Chang Wen-Han , Maida Anthony , Trieu Vuong , Lee Cynthia 
Published: November 2024

Abstract
Low-grade glioma (LGG) tumors are characterized by a low infiltration of immune cells, requiring therapies augmenting the immune response in the tumor microenvironment (TME). The Transforming Growth Factor beta (TGFB) pathway contributes to an immunosuppressive environment. We propose targeting the specific inhibition of Transforming Growth Factor Beta 2, TGFB2 mRNA, as an attractive therapeutic strategy using antisense oligonucleotides. We conducted a bioinformatic-led investigation highlighting the ratio of TGFB2:TGFB1 mRNA expression levels in the cohort of 513 TCGA patients, revealing the TGFB2 ratio as a negative prognostic indicator through utilizing a multivariate Cox proportional hazards model that included the TGFB2 ratio and age at diagnosis as linear covariates to predict overall survival (OS). The model showed a 1.8-fold higher TGFB2 ratio relative to TGFB1 mRNA expression correlated to worse OS. Furthermore, the impact of the TGFB2 ratio was significantly affected by the age at diagnosis, in which older patients exhibited worse OS at increased TGFB2 ratios. Increasing the ratio of TGFB2 relative to TGFB1, TGFB3, TGFBR1, or TGFBR2 in LGG patients led to significant increases in multivariate Cox model determined hazards ratios, HR (HR (95% CI range)) of 1.372 (1.224-1.539), 1.434 (1.288-1.560), 1.327 (1.195-1.473), and 1.381 (1.233-1.547) respectively (P&lt;0.0001 for all comparisons). Correlation of TGFB2:TGFB1/TGFB3/TGFBR1/TGFBR2 ratio across 1330 Reactome pathways using Gene Set Enrichment Analysis showed the most positively correlated genes were members of TME pathways including PD-1 signaling, Syndecan interactions, Non-integrin membrane-ECM interactions, EPH-Ephrin signaling, and Collagen biosynthesis and modifying enzymes. These results suggest that the specific targeting TGFB2 in LGG can remodel the TME for immune therapies to improve OS outcomes.
TMIC-17. TARGETING THE FLUIDIC FORCE-SENSING MECHANISM TO TREAT BRAIN TUMOR METASTASIS
Authors: Huang Xi 
Published: November 2024

Abstract
Biofluid flow generates fluid shear stress (FSS), a mechanical force widely present in tissue microenvironment. How brain tumor growth alters the conduit of biofluid, thereby impacting FSS-regulated cancer progression is unknown. Medulloblastoma (MB) is the most common malignant brain tumor in children. Dissemination of MB cells into the cerebrospinal fluid (CSF) initiates metastasis within the central nervous system. By simulating CSF dynamics based on magnetic resonance imaging of MB patients, we discovered that FSS is elevated at the cervicomedullary junction. Strikingly, we found that MB-relevant FSS promotes metastasis along mouse spinal cords. Mechanistically, FSS induces metastatic cell behaviours, including weakened cell-substrate adhesion, increased motility, cell clustering, and plasma membrane localization of glucose transporter 1 (GLUT1) to enhance glucose uptake. FSS is perceived by mechanosensitive ion channel PIEZO2, which drives actomyosin contractility-dependent GLUT1 recruitment at the plasma membrane. Genetic targeting of PIEZO2 or pharmacologic inhibition of GLUT1 mitigates metastasis. Collectively, these findings define a targetable FSS-activated mechano-metastatic cascade for the treatment of MB metastasis.
TMIC-18. ROLE OF NEUROTRANSMITTERS IN GLIOBLASTOMA PATHOPHYSIOLOGY: EMERGING INSIGHTS
Authors: Irshad Khushboo , Singh Sanjay , Ahmad Khalil Ali , Ban Kechen , Aghoghovwia Benjamin , Mahalingam Rajasekaran , Harris Momo , Alnassiry Sama , Bertrand Renae , Gargapati Aishani , Bui Nathan , Kuo Truc , Lang Frederick , Pan Yuan 
Published: November 2024

Abstract

INTRODUCTION
Glioblastoma (GBM) are the most common primary brain tumor in adults associated with a dismal patient outcome. While it is well-known that glutamatergic neurons can form functional synapses with glioblastoma cells to enhance tumor growth, lesser is known about the effects of activity of other neuronal types on glioblastoma biology, especially among different glioblastoma molecular subtypes. Here, we examined the effects of various neurotransmitters on the growth of glioblastoma cells characterized as classical, proneural and mesenchymal subtypes.

METHODS
Patient-derived glioblastoma cell lines were exposed to varying concentrations of different neurotransmitters and assessed for cell viability using CCK-8 assay. Transcriptomic data from TCGA (The Cancer Genome Atlas) database was analyzed for correlation of expression of neurotransmitter receptors (NTRs) with patient survival. Using IVY-GAP database, we compared the expression of NTRs at leading-edge versus tumor core of tumors to assess their possible involvement in cell migration and microenvironmental interactions.

RESULTS
Consistent with previous findings, we observed an increase in cell viability in all GBM cell lines after being incubated with L-glutamate. The classical subtype has a stronger growth response to L-glutamate compared to the other two subtypes. TCGA data revealed the expression of GRIK4 (glutamate ionotropic receptor kainate type subunit 4) as highest in the classical subtype as well as inversely correlated with worse patient survival in this GBM subtype, as opposed to proneural or mesenchymal patient groups. CCK8 assay also suggested that acetylcholine and dopamine increase glioblastoma cell growth. A subset of cholinergic and glutamatergic receptors (CHRM1, GRM2) was found upregulated in infiltrating/leading-edge regions of glioblastoma tumors compared to the tumor core, suggesting possible involvement in glioblastoma-neuron interactions.

CONCLUSION
Our findings suggest that GBM subtypes may differentially leverage neuro-modulatory mechanisms to support their growth. Future studies will investigate the differential neuronal responses in GBM subtypes using pharmacological/genetic approaches.
TMIC-21. PYK2/MAPK/ERK SIGNALING PATHWAY REGULATES EXTRACELLULAR VESICLE RELEASE IN GLIOBLASTOMA
Authors: Ramires Serrano Neisha , Perez Emir Perez , Kucheryavykh Yuriy , Kucheryavykh Lilia 
Published: November 2024

Abstract
Glioblastoma (GBM), the deadliest brain cancer, typically proves fatal within a year despite treatment. Tumor-associated myeloid cells (TAMs) support GBM growth, treatment resistance, and immune surveillance. Extracellular vesicles (EVs) facilitate communication between tumor and TAMs, exchanging proteins, lipids, RNA, and genetic material. As EVs can travel through the bloodstream to distant tissues, they trigger signaling pathways and metabolic changes in remote organs while also recruiting bone marrow-derived cells and modulating immune responses. Therefore, EVs serve as a crucial mechanism for the distant regulation of the tumor’s immune microenvironment. We hypothesize that Pyk2/MAPK/Erk signaling regulates EV release by modulating the actin cytoskeleton, impacting TAM infiltration and activation in tumors. This study aims to investigate the role of Pyk2/MAPK/Erk in specific EV release in GBM cells, potentially offering insights into therapeutic targets. Using confocal imaging and flow cytometric analysis of EVs, purified from medium conditioned from human primary GBM cell lines with and without Pyk2 CRISPR/Cas9 knock-out (Pyk2KO), the study identified that Pyk2KO cells do not release the population of EVs with diameter bigger then 600nm and up-regulate release of smaller EVs. Additionally, flow cytometric analysis of EVs, released from cells, fluorescently labeled with membrane dye carboxyfluorescein diacetate succinimidyl ester (CFDA-SE), detected 14% of CFSE+ events in EV’s population, purified from Pyk2WT, vs. to 2.5% from Pyk2KO cells. Membrane labeling of cells enables the tracking of microvesicles (MV) shedding and was used to differentiate between MV and ES based on the process of their biogenesis. Considering that larger size and the transition of fluorescence from the plasma membrane are indicative of MVs, our data indicate that Pyk2 is involved in the regulation of MV release. FUNDING: PRSTRT2022 and NIH Grant 1R15CA287203
TMIC-24. BICARBONATE RECEPTOR SLC4A4 SENSITIZES INFILTRATING GLIOBLASTOMA CELLS TO CHANGES IN EXTRACELLULAR PH
Authors: Patel Kunal , Perryman Travis , Prabhu Ashna , Harper Stuart , Dudley Lindsey , Delgadillo Alondra , Gor Aidan , Bhaduri Aparna , Kornblum Harley 
Published: November 2024

Abstract

BACKGROUND
Glioblastoma progression involves changes in extracellular pH (pHe) related to rapid cell turnover and growth. There exist differences in pH between contrast-enhancing solid tumor and non-enhancing infiltrating tumor. SLC4A4 is a two-way bicarbonate transporter used in cortical astrocytes to buffer intracellular pH.

METHODS
In patients undergoing surgery for newly diagnosed IDH wild-type glioblastoma, we obtained tissue from solid tumor and infiltrating tumor. Single-nucleus RNA sequencing (n=15), immunohistochemistry (n=20) were carried out to identify SLC4A4 in infiltrating tumor beyond the contrast enhancing edge. SLC4A4 knock-down models were used to evaluate functional biology of this bicarbonate receptor using our tumor – cortical organoid model of infiltrating glioma and gliomaspheres. pH measurements were recorded using pH sensitive microelectrodes to evaluate changes on pH buffering ability of tumor cells during acid titration assays.

RESULTS
Single-nucleus RNA sequencing (n=15) and spatial RNA sequencing (n=3) showed SLC4A4 to be the highest expressed transmembrane receptor on infiltrating glioblastoma cells but not solid tumor. IHC (n=20) confirmed higher protein expression in infiltrating tumor (p=0.0390). Infiltrating cells were specifically sensitive to decreasing pHe (p=0.0105). In the infiltrating glioma cortical-organoid model, the slc4a4- had increased proliferation (GFP+ cell quantitation; n=10, p=0.0410). There was also increased proliferation in wild-type cells treated with SLC4A4 inhibitor DIDS (n=10, p=0.0016). Immunostaining of these models showed that downmodulation of SLC4A4 was associated with increased Ki67 and decreased caspase staining.

CONCLUSIONS
SLC4A4 plays a role in pH buffering in glioblastoma. We hypothesize that loss of SLC4A4 in solid tumor allows for desensitization of these cells to an acidic extracellular environment and allows for increased tumor growth and density while infiltrating tumor remains sensitivity to changes in pHe. An understand of pH regulation may lead to therapeutic efficacy through pH modulation of tumor.
TMIC-26. IMMUNE CELL DYNAMICS WITHIN GLIOMAS: THE INFLUENCE OF GRADE AND IDH STATUS
Authors: Grewal Eric P , GK Richardson Leland , Sun Jing , Ramapriyan Rishab , Martinez-Lage Maria , Miller Julie J , Carter Bob S , Cahill Daniel P , Curry William T , Choi Bryan D 
Published: November 2024

Abstract
Mutations in isocitrate dehydrogenase (IDH) are known to significantly impact the prognosis and biology of diffuse gliomas. A number of studies have compared the immune microenvironment of IDH-wildtype glioma versus IDH-mutant glioma, and have also characterized the impact of mutant-IDH on lymphocytes. However, few studies have explored how mutant-IDH may affect tumors as they progress and increase in grade, or have delved into the myeloid immune cell compartment. Thus, we sought to understand whether tumor progression affected intratumoral immune cell composition within IDH-mutant glioma, and aimed to compare IDH-mutant versus IDH-wildtype glioma in both humans and mice. Using bulk RNA sequencing, we compared paired samples from patients with IDH-mutant glioma before and after progression, focusing on differentially-expressed immunological genes and relative immune cell proportions. We also compared grade 4 IDH-mutant astrocytoma cases to IDH-wildtype glioblastoma, performing both transcriptomic and cellular analyses. Finally, we engineered murine glioma cells to test the effect of mutant-IDH alone in the tumor microenvironment. We found that multiple immune-related genes distinguish low- and high-grade IDH-mutant glioma, and that high-grade tumors contain greater proportions of suppressive myeloid cells. When comparing IDH-wildtype to IDH-mutant glioma, we found enrichment of suppressive macrophages and myeloid-derived suppressor cells (MDSC) in IDH-wildtype tumors. Finally, our murine model of IDH-wildtype versus IDH-mutant glioma mirrored many of the myeloid cell shifts observed in human tumors. Our data show that progression of IDH-mutant tumors is a significant immunological phenomenon, associated with marked alterations in the tumor immune microenvironment. We also show that IDH-mutant glioma harbors greater inflammatory signatures and fewer suppressive myeloid cells than IDH-wildtype glioma, and that engineering mutant IDH into murine tumors is sufficient to model these differences. These findings improve our understanding of key intratumoral cell populations that may be harnessed by future immunotherapeutic strategies.
TMIC-29. IMMUNE SPECIFIC IMAGING TECHNIQUES IN GLIOBLASTOMA: SELFI MRI IDENTIFIES AGGRESSIVE AND IMMUNOSUPPRESSIVE BIOLOGICAL FEATURES THAT CONTRIBUTE TO THERAPEUTIC RESISTANCE
Authors: Stoller Jared , Schwartz Daniel , Wongsawaeng Doonyaporn , Holland Samantha , Stateler Cooper , Kersch Cymon , Starkey Alicia , Muldoon Leslie , Ambady Prakash , Raslan Ahmed , Dogan Aclan , Sanusi Olabisi , Harrington Christina , Neuwelt Edward , Barajas Ramon 
Published: November 2024

Abstract
Gadolinium (Gd) enhanced MRI is nonspecific for identifying aggressive glioblastoma biology. Glioblastoma-associated macrophages (GAMs) are pivotal in regrowth. Segregation and Extravascular Localization of Ferumoxytol Imaging (SELFI) is a quantitative immune specific MRI technique. SELFI+ values quantify M2 GAMs by phagocytized Ferumoxytol (Fe), while SELFI- values delineate intravascular Fe, cerebral blood volume. The relationship between SELFI and biology driving therapeutic resistance remains unknown. We aimed to determine if SELFI identified immunosuppressive GAMs and biology contributing to poor outcomes, a capability not yet achievable in clinical practice. This prospective study included four patients with glioblastoma. All underwent preoperative Gd and Fe (7 mg/kg up to 510 mg) enhanced MRI allowing for image guided biopsy based on Gd enhancement and FLAIR hyperintensity. RNA was analyzed on GeneChip Clariom Arrays. Intraoperative biopsy location was referenced to MRI for placement of volumes of interest (VOIs). VOIs quantified MRI phenotype and SELFI values. Gene Set Enrichment Analysis (GSEA) assessed differential expression between MRI features. T-test assessed differences in SELFI (p &lt;0.05) and GSEA significance was assessed by normalized enrichment score (NES) and false discovery rate (FDR) q-value. Four patients provided 36 image guided tissue samples with sufficient quality to assess the causal relationships between MRI features and transcriptomics. Stratification by patient MGMT methylation status (N= 3 unmethylated) demonstrated Gd+ regions had significantly elevated SELFI+ values (Mean±SD, Gd+ = 0.24±0.17, Gd- = 0.08±0.09, P&lt;0.01). GSEA demonstrated that tissues with elevated SELFI+ and lowered SELFI- values were comprised of significantly upregulated hypoxia and transforming growth factor-beta (TGFβ) signaling; among others (NES&gt;1.5, FDR q-value&lt;0.05). SELFI MRI uniquely quantifies glioblastoma by localizing sites of biological aggressiveness known to contribute to therapeutic resistance and disease recurrence. Patient enrollment continues to further define the causal relationships between SELFI, GAMs, and glioblastoma biology.