tbuckley/cabot-search huggingface dataset:
IMMU-06. H-FERRITIN AFFECTS IMMUNE CELL INFILTRATION INTO THE GLIOBLASTOMA TUMOR MICROENVIRONMENT IN A SEX-BIASED MANNER
Authors: Aurosman Pappus Sahu, Kondaiah Palsa, Ganesh Shenoy, Timothy B Helmuth, Becky Slagle-Webb, Elizabeth Neely, James R Connor
Journal: Neuro-Oncology (2024)

Abstract Glioblastoma (GBM) is an aggressive brain cancer that is sexually dimorphic in nature, with females less susceptible to developing it, responding better to therapy, and gaining a survival advantage. Iron metabolism is also sexually dimorphic and has been shown previously to contribute to sex bias in GBM. Ferritin is an iron-storing protein that has elevated expression in tumor cells and is essential to GBM growth. Here, we used an in vivo GBM model consisting of heterozygous FTH1 knockdown (FTH1-KD) mice and GL261 cells to study the role of host ferritin in GBM progression. We have previously published that FTH1 knockdown in female mice decreased overall survival compared to WT (P = 0.03). This work delves into potential mechanisms that contribute to this survival difference. GBM was induced in 6-8 weeks-old mice by injecting 2*10^4 GL261 cells intracranially by a stereotaxic apparatus. The tumor volume was measured 3 weeks post-injection by magnetic resonance imaging, followed by image segmentation. We observed that FTH1 knockdown did not affect tumor volume. Flow cytometry was used to examine the immune infiltrating cells (CD45high) population in the tumor-bearing hemisphere. In females, there was an increase in CD11b+ cells in FTH1KD mice compared to WT mice (P = 0.0607). Similarly, Female FTH1-KD mice had a lower T cell (CD3+) population than Female WT mice (P = 0.0033). This decrease in infiltrating CD3 cells was due to a reduction of CD4 T cells (CD3+ CD4+) in female FTH1-KD mice compared to female WT mice (P = 0.0375). We observed no difference in CD8 T cells (CD3+ CD8+). These data indicate that host ferritin affects immune infiltration into GBM cells in a sex-biased manner.
IMMU-09. REVERSING SYSTEMIC T CELL DYSFUNCTION TO LICENSE IMMUNOTHERAPY IN INTRACRANIAL TUMORS
Authors: Lucas Wachsmuth, Selena Lorrey, John Finlay, Corey Neff, Katayoun Ayasoufi, Mackenzie Price, Rachael Reesman, Quinn Ostrom, Peter Fecci
Journal: Neuro-Oncology (2024)

Abstract Intracranial tumors present unique challenges for immunotherapy. These can include both local and systemic modes of immune suppression, the mechanistic underpinnings of which are incompletely understood. Our work reveals that intracranial tumors elicit systemic increases in circulating catecholamine levels, and that this chronic sympathetic hyperactivity results in T cell dysfunction that impedes immunotherapeutic efficacy. We show that treatment with b-adrenergic blockade can partially overcome the negative impacts of chronic sympathetic hyperactivity by increasing NF-kB activity in immune cells, restoring T cell polyfunctionality, favorably modifying the tumor microenvironment, and extending survival in murine models of glioblastoma treated with immune-based therapies. Furthermore, we demonstrate that extended survival is also observed in glioblastoma patients receiving b-adrenergic blockade, as well as in patients with melanoma and lung cancer brain metastases who received b-blockade alongside concomitant immune checkpoint inhibition. Importantly, while local sympathetic hyperactivity in the tumor microenvironment and b-blockade also impact the anti-tumor immune response in the context of extracranial disease, these effects are markedly more pronounced in intracranial disease. Taken together, these data reveal that sympathetic hyperactivity facilitates systemic immune dysfunction in the setting of intracranial tumors and highlight a novel role for the application of b-adrenergic blockade to license immunotherapy in intracranial malignancies.
EPID-09. THE NATURAL HISTORY AND MOLECULAR ARCHITECTURE OF INCIDENTAL MENINGIOMAS
Authors: Minh Nguyen, William Chen, Kanish Mirchia, Stephen Magill, Ramin Morshed, David Raleigh
Journal: Neuro-Oncology (2024)

Abstract The prevalence of asymptomatic, incidental meningiomas is increasing due to greater frequency of brain imaging. This retrospective cohort study of adult patients presenting at a single institution from 1996-2020 integrated clinical data, serial magnetic resonance imaging (MRI) volumetrics, DNA methylation profiling, and targeted gene expression profiling to define the natural history and molecular architecture of incidental meningiomas. Volumetrics were calculated from contrast-enhanced brain MRIs at time of diagnosis compared to serial surveillance MRIs (average 3 MRIs per patient pre-intervention, range: 1-12) DNA methylation groups and gene expression risk scores were defined for 123 samples that underwent resection. Time-to-event analyses were performed for progression-free survival (PFS), symptom-free survival (SFS), and treatment-free survival (TFS). The cohort included 238 meningiomas from 207 patients. Median age at diagnosis was 59 years and 81.5% of patients were female. Median clinical and imaging follow-up were 9.1 and 6.7 years, respectively, during which time 50.8% progressed. Median maximum diameter and volume at diagnosis were 2.20 cm and 4.25 cm3, respectively, and median pre-treatment volumetric growth rate was 19.2% per year. Median pre-treatment PFS and TFS were 3.10 and 1.27 years, respectively, and median SFS and post-treatment PFS were not reached. Cox proportional hazards regression identified maximum diameter at diagnosis as a significant predictor of worse pre-treatment PFS (multivariate HR 1.65 per 1 cm [95% CI 1.19–2.28], p=0.0027) and worse TFS (multivariate HR 1.44 per 1 cm [95% CI 1.17–1.76], p&amp;lt;0.001). Skull base tumors had with worse SFS (multivariate HR 2.48 [95% CI 1.02–6.00], p=0.045). Molecular and histological features among incidental meningiomas that ultimately underwent resection (n=176, 74.0%) were reassuring (89.2% WHO grade 1, 10.2% WHO grade 2). These findings suggest maximum diameter at diagnosis of incidental meningiomas is significantly associated with earlier progression and eventual treatment, and skull base tumors have earlier symptom development.
DDDR-15. UTILIZING DEEP DOCKING AND ARTIFICIAL INTELLIGENCE FOR THE DISCOVERY OF NOVEL PARP1-SELECTIVE INHIBITORS FOR USE AGAINST BRAIN TUMORS
Authors: Sarah Truong, Fuqiang Ban, Jason Smith, Beibei Zhai, Louise Ramos, Mona Marzban, Fariba Ghaidi, Hans Adomat, Xiaoqi Chen, John Langlands, Dennis Brown, Jeffrey Bacha, Colin Collins, Artem Cherkasov, Mads Daugaard
Journal: Neuro-Oncology (2024)

Abstract Brain tumors, including primary brain tumors and central nervous system (CNS) metastases, remain among the most challenging malignancies to treat, with therapeutic options often limited by the inability of drugs to penetrate the blood-brain barrier. Poly(ADP-ribose) polymerase (PARP) is a key enzyme in DNA repair, and inhibition of PARP1 specifically drives synthetic lethality in BRCA-mutated disease. While they’ve achieved commercial success, first generation PARP inhibitors are limited in their utility as they cannot readily pass through the blood-brain barrier and have adverse side effects, likely driven by the collateral inhibition of PARP2. Development of a PARP1-selective, CNS penetrant inhibitor could reduce toxicity, while providing a new therapeutic option for brain tumors. Traditional drug discovery methods are time-consuming and costly, necessitating innovative approaches. Here, we describe the application of Deep Docking, an advanced artificial intelligence (AI) approach, to discover a novel, PARP1-selective inhibitor for use against brain tumors. Deep Docking utilizes deep learning to accelerate the prediction of the binding affinity of a large number of compounds to target proteins, streamlining the virtual screening process and allowing for rapid docking of billions of compounds against the PARP1 protein. Additionally, state-of-the-art generative algorithms and deep learning techniques for predicting drug-like properties such as metabolism, permeability, and safety profiles, can be combined to rapidly perform hit-to-lead optimization. We will present preliminary Deep Docking screening results from billions of compounds, identifying several with predicted high binding affinities for PARP-1. Validating in vitro and in vivo data, including PARP1 selectivity, metabolic stability, pharmacokinetic profile, CNS penetration and safety profile, will be described. Application of the Deep Docking AI platform is being used to significantly accelerate the discovery of a selective PARP-1 inhibitor for brain tumors. This approach will not only improve the efficiency of drug discovery but also enhance the specificity and efficacy of potential therapeutics.
CSIG-30. EXPLORING THE ROLE OF CAPICUA (CIC) IN RESISTANCE MECHANISMS OF MEK INHIBITORS IN GLIOBLASTOMA
Authors: Phooja Persaud
Journal: Neuro-Oncology (2024)

Abstract Glioblastoma multiforme (GBM) is the most common and fatal primary brain tumor, resistant to conventional therapy. Despite its heterogeneous nature, a key feature of GBM is aberrant kinase signaling. Specifically, hyperactivation of receptor tyrosine kinases (RTK) and their downstream tumorigenic effectors Ras/MEK/Extracellular Signal Regulated Kinase (ERK) pathway are attributed to the aggressive nature of GBM. Capicua (CIC) is a High Mobility Group (HMG) box transcriptional repressor that directly binds to DNA and counteracts the transcription of genes typically expressed only in response to RTK activation such as oncogenic transcription factors ETV1/4/5. Hyperactive MEK/ERK signaling in GBM causes CIC degradation. The mechanism of CIC’s repressor function is not well understood, however, transcriptional repressors (like CIC) typically form co-repressor complexes to repress target genes. We discovered a novel interaction between CIC and the transcriptional regulator yin yang 1 (YY1), a context-dependent transcription factor that can repress or activate gene expression. We uncovered that 90-kDa ribosome S6 protein kinase (p90RSK), a downstream effector of ERK and a known CIC regulator, mediates the CIC/YY1 interaction. Interestingly, we found re-activation of p90RSK following MEK/ERK inhibition implicating p90RSK in the resistance mechanism of RTK/MEK/ERK inhibition in GBM. We hypothesize that p90RSK inhibition will stabilize the CIC/YY1 co-repressor complex and re-sensitize towards MEK/ERK inhibition. Patient-derived glioma stem-like cells (GSCs) were treated with increasing doses of BI-D1870 or LJI308 (p90RSK inhibitors) with and without selumetinib (MEK inhibitor) and various functional assays were performed to examine the effect of p90RSK inhibition on the CIC/YY1 complex and sensitization to MEK/ERK inhibition. Treatment with BI-D1870 and LJI308 markedly reduced viability and mRNA expression of ETV1/4/5 indicating that p90RSK inhibition may mediate CIC /YY1 DNA binding ability. Importantly, inhibiting p90RSK sensitized GSCs to MEK/ERK inhibition. These results highlight the importance of downstream p90RSK inhibition in stabilizing CIC/YY1 repressor complex function and sensitizing cells to RTK/MEK/ERK inhibition.
CSIG-27. GLIOBLASTOMA CELL STATE PLASTICITY AND THERAPEUTIC RESISTANCE IS MEDIATED BY BRD2
Authors: Raghavendra Vadla, Brett Taylor, Shunichiro Miki, Yohei Miyake, Daisuke Kawauchi, Frank Furnari
Journal: Neuro-Oncology (2024)

Abstract GBM is a highly aggressive primary brain tumor in adults, notable for its heterogeneity, high recurrence rates, and increased resistance to therapy. Multi-omics analyses have consistently identified three distinct transcriptionally defined cell states – proneural (PN), classical (CL), and mesenchymal (MES) – in IDH-wildtype GBM, with high plasticity among these states in response to diverse stimuli. Transition of GBM cells to a MES cell state is particularly associated with high invasiveness, resistance to therapy, and recurrence. However, the underlying mechanisms driving the MES transition remain poorly understood. In this study we identified the PTEN/NF-kB/BRD2 pathway as key driver of the MES transition, with BRD2 acting as a crucial epigenetic modulator for cell state transitions in GBM. We demonstrate that PTEN plays a critical role in regulating the chromatin binding of BRD2, BRD4 and p65/RelA. Additionally, acetylation of RelA at lysine 310 is required for BRD2 localization to the promoters of MES genes, which is essential for their expression. Loss of BRD2 leads to transition of GBM cells from MES to PN cell state and displayed enhanced sensitivity to ionizing radiation (IR). Further, bromo domains (BDs) of BRD2 are important for MES transition, as mutations in these domains resulted in transitioning of GBM cells from MES to other cell states. Furthermore, we show that BD2-specific BET inhibitors displace BRD2 from MES gene promoters, abrogate MES transition, and enhance GBM sensitivity to IR. Using a brain-penetrant BD2 inhibitor, we effectively reduced GBM cell invasion and tumor-associated microglia/macrophage (TAM) abundance in orthotopic xenograft models. These findings establish BRD2 as a key regulator of MES transition and therapeutic resistance in GBM models, paving the way for the use of bromodomain-specific BET inhibitors in targeting MES GBM.
CNSC-69. GLIOBLASTOMA-NETWORK CONNECTIVITY IS REGULATED THROUGH ALTERATIONS IN CHLORIDE HOMEOSTASIS AND GABAERGIC SIGNALING
Authors: Saritha Krishna, Cesar Nava Gonzales, Andy Daniel, Kevin Lee, Abraham Dada, Hunter Yamada, Vardhaan Ambati, Pavithra Viswanath, Shawn Hervey-Jumper
Journal: Neuro-Oncology (2024)

Abstract The specific pathophysiological mechanisms underlying glioma-related epilepsy, which presents an unfavorable clinical course, are still not well explored. To identify the candidate pathways involved in glioblastoma-induced neuronal hyperexcitability, we used high-density electrode arrays in vivo in humans to record local field potentials from cortically projecting gliomas and identified hyperexcitable intratumoral regions with elevated functional connectivity to the brain. Single-cell RNA sequencing (13,730 cells analyzed) of the functionally connected intratumoral regions identified several circuit assembly and GABAergic signaling genes elevated in glioma-intrinsic neurons, including the sodium-potassium-chloride co-transporter 1 (NKCC1), which accumulates chloride in the cells. We hypothesized that the hyperexcitable behavior of glioma-intrinsic neurons in glioblastoma is mediated by elevated NKCC1 and chloride dysregulation and that inhibiting NKCC1 would reinforce the inhibitory action of GABA and rescue the neuronal hyperresponsive phenotype. Single-nucleus (sNuc-seq) sequencing was performed on neuron-glioblastoma co-cultures (54,000 cells analyzed) to determine NKCC1-facilitated GABAergic signaling in glioblastoma-mediated neuronal responses. Mechanistic and functional studies using perforated whole-cell patch-clamp recordings, multielectrode array, calcium, and chloride imaging for validating therapeutic vulnerabilities to NKCC1 silencing by shRNA knockdown and by the FDA-approved drug bumetanide were performed using in vitro and organotypic mouse slice culture models. sNuc-seq revealed an upregulation of neuronal NKCC1 and GABAA receptors when co-cultured with NKCC1-high-expressing glioblastoma cells, indicating the strong association between neuronal NKCC1 and GABAergic signaling. Electrophysiological analysis of glioblastoma-neuron co-cultures demonstrated increased network burst synchrony and a positive shift in the GABA reversal potential (EGABA). This increase was eliminated in the presence of NKCC1 inhibition using bumetanide and shRNA knockdown, which correlated with a significant decrease in intracellular neuronal chloride. Mechanistically, glioma NKCC1 downregulation significantly decreased GAP43-mediated tumor microtube (TMT) formation. Whether this reduced TMT formation also results in decreased chloride release by glioma cells, thereby altering neuronal chloride equilibrium, is currently under investigation. Collectively, these findings aim to identify a new mechanism of glioma-associated epilepsy, which may provide a novel approach to treatment.
NCOG-12. TREATMENT AND MORTALITY OF PRIMARY BRAIN TUMORS: A SINGLE CENTER OBSERVATIONAL STUDY OF GLIOBLASTOMAS AND ASTROCYTOMAS
Authors: John Santare, David Sosidko, Claire Dawyot, Mina Aiad, Harsh Bhalala, Elizabeth Forget, Sophia Starner, Meriam Deeb, Melissa Wilson
Journal: Neuro-Oncology (2024)

Abstract Glioblastoma multiforme (GBM) is a WHO grade IV malignant tumor with a relatively poor prognosis (median survival of 15 months). Astrocytomas are WHO grade I-III tumors with a better prognosis than GBM; their median survival ranging from 2-10 years. We assessed the response to various mainstay treatment modalities in patients with GBM and astrocytoma, expecting to find that surgery and stereotactic radiation (SRS) treatment confer greater survival benefits than non-surgical and whole brain radiation (WBRT) options. We analyzed 108 patients at St. Luke’s University Health Network (SLUHN) who were previously diagnosed with a primary brain tumor consistent with GBM (90) or astrocytoma (18) prior to January 1, 2023. Mainstays of treatment were surgery with or without different radiation modalities (WBRT and SRS, and WBRT+SRS). Glioblastoma typically affected older patients (65.5), had mostly single lobe involvement (86.7%), and was predominantly located in the frontal (41.1%) and temporal lobes (37.7%). Astrocytoma was slightly younger (51.2), less often single lobe (72.2%), and mostly involved the frontal (44.4%), temporal (44.4%), and parietal lobes (33.3%). GBM found the greatest benefit from WBRT (without co-occurring SRS) with an increase of 16.4 months to 20.2 months (p=.789). Surgery, regardless of radiation status, appeared to provide the greatest benefit for patients with astrocytoma increasing average lifespan from 36.7 months to 53.6 months (p=.181). Patients with glioblastoma that underwent surgery also had increased survival of 18.2 months compared with nonsurgical patients at 12 months (p=0.097). While we were interested to see the impact these treatment modalities had on patient survival, our sample size was small and our results lacked statistical significance. Future studies with greater sample sizes would help determine whether statistical significance is correlated with meaningful clinical outcomes.
CNSC-66. STRUCTURAL AND ELECTROPHYSIOLOGICAL CONNECTIVITY IN GLIOBLASTOMA IS MEDIATED BY TUMOR AND IMMUNE DERIVED CYTOKINES
Authors: Thiebaud Picart, Saritha Krishna, Andy Daniel, Abraham Dada, Sena Oten, Hyer Jeanette, Shawn Hervey-Jumper
Journal: Neuro-Oncology (2024)

Abstract BACKGROUND In glioblastomas (GBM), the pleiotropic cytokine interleukin-6 (IL-6) upregulates PD-L1 expression. This results in local immunosuppression favorable to tumor progression, and may account for the limited efficacy of immune checkpoint inhibition. Additionally, IL-6 increases synaptogenesis during development, and contributes to neuronal network remodeling following focal brain or spinal cord injury. Therefore, the aim was to determine whether IL-6 contributes to GBM-induced circuit remodeling from a structural and electrophysiological perspective. METHODS In magnetoencephalography (MEG)-based intratumoral regions of High- (HFC) and Low-Functional Connectivity (LFC) from GBM patients, the expression of IL-6 and GAP43 was compared using bulk and single-cell RNA sequencing and immunofluorescence staining in biological replicates (n=44). In mouse postnatal cortical neurons and primary patient-derived GBM cell cocultures, the expression of Ki67, GAP43, tumor connectivity and neuronal activity were monitored after exogenous application of recombinant human IL-6 (rIL-6) or microglial depletion using PLX5622. Results. IL-6 and GAP43 were overexpressed in HFC compared to LFC regions. In neuron-GBM cocultures, the tumour proliferation index was significantly increased by rIL-6 and decreased by PLX5622. Morphologically, the number of microtubes per tumor cell was significantly increased by rIL-6 and decreased by PLX5622. The expression of GAP43 was inconstantly increased by rIL-6, suggesting the regulation of other pathways involved in tumour microtube formation. Multielectrode array recordings showed a significant increase or decrease in the neuronal activity, following the addition of rIL-6 or microglial depletion, respectively. CONCLUSIONS IL-6-signaling increases proliferation, structural and electrophysiological connectivity in gliomas and may contribute to neuronal network hyper-excitability and synchrony. Microglial depletion provided opposite effects. Additional experiments are mandatory to determine whether the effects of IL-6 on GBM cells depend on the presence of microglial cells or not. These data will be critical to design new therapeutic options, likely to improve the oncological and functional outcomes of patients treated for GBM.
EPCO-56. INHERITED PREDISPOSITION TO ADULT GLIOMAS: OVERVIEW OF THE CURRENT CLINICAL PRACTICE AND FUTURE RECOMMENDATIONS
Authors: Saumya Patel, Lara Balay, Tara Maga, Stefania Maraka
Journal: Neuro-Oncology (2024)

Abstract Gliomas are the most common adult primary malignant brain tumor and occur in ages 45-65 years old. While most gliomas are sporadic in nature, a small portion is related to cancer predisposition syndromes (CPS), such as Li Fraumeni or Lynch syndromes. Given that 5–10% of patients will have a family history of glioma, there is currently an effort in identifying germline variants associated with gliomas. Additionally, with the advent of somatic tumor testing, it is possible to pick up suspected germline mutations in genes that cause CPS. Our experience includes a 32-year-old patient diagnosed with astrocytoma IDH mutant, Grade 2 who was found to have a BRAC1 mutation on somatic brain tumor testing. 10 years later, the patient was found with metastatic ovarian cancer and a germline BRAC1 mutation. Early identification of CPS can lead to early detection or prevention of malignancies in affected patients and relatives. However, gliomas are rarely the primary or presenting tumor of CPS, and guidance of CPS screening for these individuals is still lacking. Due to the increasing interest and importance of CPS testing in patients with glioma we have developed a collaborative protocol between our neuro-oncologists and genetic counselors aso that patients have access to germline testing. We propose that all patients with glioma at age of 50 or under, patients with strong family history of cancer including gliomas, and patients with suspected germline mutations based on tumoral somatic mutational profile should be referred to the genetic counselors. Our preliminary findings include 8 patients who completed germline genetic testing. Of these, one patient tested positive for a BRCA1 pathogenic variant. We are planning to continue to collect this data to better inform clinical practice.