bluuebunny/crossref_metadata_2025 huggingface dataset:
BIOM-73. CYTOKINE DYNAMIC DURING RADIATION THERAPY PREDICTS SURVIVAL IN GLIOBLASTOMA
Authors: Puri Sushant , Sloan Lindsey , Huang Peng , Doucet Michele , Ganguly Sudipto , Kleinberg Lawrence
Published: November 2024

Radiation Therapy affects a wide range of circulating lymphocyte subpopulations that are integral to mounting a successful lymphocyte-mediated immune response. Lymphopenia is associated with inferior tumor control and could be addressed to improve outcomes in glioblastoma. RT is one significant and potentially actionable iatrogenic suppressor of immune response that may limit the success of therapy. We hypothesized that a comprehensive evaluation of serial cytokine measurements during concurrent radiation and chemotherapy in glioblastoma will provide information about systemic immune status during treatment. 16 patients were enrolled in a single-institution, observational, immune surveillance study between 2018 and 2019. Peripheral blood was collected prior to starting radiation, and then weekly for a total of 7 timepoints. Plasma was isolated from blood, and cytokine levels were measured with a Luminex 23-cytokine panel. Survival was defined at 2 years since diagnosis. Patients >2 years were called survivors and <2 years were called non-survivors. Cytokine levels were compared with a cohort of 4 healthy controls. All data are log2 transformed using formula log2(x+1). ANOVA was used to find cytokines that differ among 3 groups. Only for those cytokines with significant ANOVA results, pair-wise t-test was performed. We found a total of 12 cytokines that were increased in plasma in glioblastoma patients undergoing radiation compared to control. Top cytokines to show differences were IL-10, M-CSF, TGF-b3 and TIM-3 (p<0.05). The others to show a difference were IP-10, MCP-1, TGF-b2, IL-34, PD-L1, LAG-3, PD-1, and CTLA-4. These cytokines are known to be immunosuppressive, and our results demonstrate a soluble mechanism of immunosuppression in this patient population. This cytokine signature can predict early during treatment the overall survival in patients with glioblastoma.
BIOM-76. EXPLORING CSF MICRORNA SIGNATURES AS DIAGNOSTIC BIOMARKERS IN IDH-WILDTYPE DIFFUSE GLIOMAS
Authors: Pirhoushiaran Maryam , Walker-Charles Kamilah , Putluri Satwik , Patel Nehal , Wang Daniel H , Arjuna Srividya , Dono Antonio , Nguyen Sophia , Huse Jason T , Kerrigan Brittany C Parker , Esquenazi Yoshua , Patel Chirag B , Lang Frederick F , Ballester Leomar Y
Published: November 2024

The most prevalent malignant tumors of the central nervous system are adult-type diffuse gliomas. Isocitrate dehydrogenase (IDH) mutations are identified in a subset of diffuse gliomas, leading to two distinct subtypes of gliomas: IDH-wildtype and IDH-mutant. In comparison to IDH-mutant gliomas, IDH-wildtype gliomas tend to be associated with a more rapid progression and lower overall survival rates. The analysis of differentially expressed microRNAs (DE-miRNAs) in cerebrospinal fluid (CSF) of IDH-wildtype diffuse gliomas could provide an effective and non-invasive approach to assist in the early diagnosis, classification, and management of the disease. Extracellular vesicle (EV)-derived miRNAs obtained from the CSF of 11 patients with IDH-wildtype diffuse gliomas and 8 controls were analyzed by microRNA sequencing (miRNA-seq). DE-miRNAs were defined using p-value≤0.05 and absolute log2 fold change (log2FC) ≥1. Candidate DE-miRNAs were validated by qRT-PCR in 24 samples (15 IDH-wildtype vs. 9 control) using the 2-ΔΔCT method, followed by receiver operating characteristic (ROC) curve analysis. Hsa-miR-24-3p was used as the internal control. miRNA-seq analysis identified hsa-miR-484, hsa-miR-223-3p, hsa-miR-1246, hsa-miR-323a-3p, hsa-miR-106b-3p, hsa-miR-21-5p, hsa-miR-15a-5p, has-miR-15b-5p, and hsa-miR-92a-3p among the top 20 upregulated miRNAs in the CSF of patients with IDH-wildtype diffuse gliomas. Further analysis by qPCR showed that patients with IDH-wildtype diffuse gliomas had significantly higher levels of has-miR-21-5p (2.28 ± 2.33) compared to control subjects (-2.22e-007 ± 1.08, p=0.012). The ROC curve analysis revealed an area under the curve (AUC) of 0.84 (95% CI, 0.68-1.0) for has-miR-21-5p CSF levels in distinguishing IDH-wildtype diffuse gliomas from control subjects. EV-derived miRNAs in CSF, including has-miR-21-5p, have the potential to distinguish IDH-wildtype diffuse gliomas from control individuals in a minimally-invasive manner and serve as diagnostic biomarkers.
BIOS-01. MACHINE LEARNING-BASED PREDICTION OF INPATIENT CARE COSTS FOR PATIENTS WITH BRAIN METASTASES: A REAL-WORLD ANALYSIS
Authors: Ozair Ahmad , Chen Chixiang , Woodworth Graeme , Mukherjee Debraj
Published: November 2024

INTRODUCTION

Brain metastases (BMs) are increasingly a cause of significant cancer-related morbidity, mortality, and economic burden. While BM-related healthcare costs have been previously described, predictive analytics based on contemporary cohorts, particularly for inpatient care, remain unavailable. This study sought to evaluate inpatient care costs (IPCC) and associated reimbursements for patients with BMs and perform predictive modeling through supervised machine learning (sML) using a contemporary, commercial US claims database.

METHODS

This retrospective study, reported following STROBE and TRIPOD+AI reporting guidelines, included adult patients (aged 18-65 years) in the United States (US) with BMs included in the MarketScan Commercial Claims and Encounters Database who received inpatient care during January 2016 to December 2021. Eligible patients were identified using ICD-10 codes. IPCC measures were adjusted using the Medical Care component of the 2023 Consumer Price Index. The primary study outcome was total IPCC, represented by adjusted gross total payments. After log-transformation performed due to data skew, sML was carried out using Random Forest algorithm with 1000 iterations with a 70:30 training-test data split, followed by residual analysis and evaluation of predictive performance using root-mean-squared error (RMSE), out-of-bag error (OOBE), and calibration curve. Multivariable linear regression was carried out for sensitivity analyses.

RESULTS

A total of 25117 unique inpatient admissions across 13477 BM patients were included, with median (IQR) age of 57 years (51-61). Gross median (IQR) CPI-medical-care-adjusted values per admission were: total payments $28,119.51 (16847.45-55111.67); hospital payments $24,678.74 (14601.66-47864.84); and payments to principal physician $884.80 (441.07-2434.15), being 3.6% (IQR 1.9-6.8) of total payment. Median inpatient length of stay was 4 days (IQR 2-8). ML model had an OOBE of 0.61 and, using test data, RMSE of 0.85, indicating robust performance. No major deviations were found on residual analysis.

CONCLUSIONS

Contemporary IPCCs for BM patients in US are substantial but driven minimally by payments to principal physician. sML may be utilized to successfully predict IPCC for BM patients.
CNSC-03. HIGH EXPRESSION OF PICCOLO AND SYNTAXIN-1A IN PAEDIATRIC MEDULLOBLASTOMA DUE TO BOTH: HIGH NEURONAL FRACTION AND ENDOGENOUS EXPRESSION
Authors: Timmer Marco , Kuhl Saskia , Goldbrunner Roland
Published: November 2024

Emerging evidence indicates that the “healthy” nervous system contributes to the pathogenesis of cancer. Tumor cells were found to form ultra-long protrusions with distinct synapses, mainly in the infiltrative zone, resulting in a neuron-to-brain tumor synaptic communication. Located at the presynapse, proteins of the cytomatrix of the active zone have been identified to maintain highly specialized functions in neurons. Further, the proteins were shown to be involved in progression in various tumors, but little is known about their role in brain tumors. This study examined the expression of CAZ proteins in glioma and medulloblastoma. Tumor samples of Astrocytoma, glioblastoma, pilocytic astrocytoma and medulloblastoma were obtained during neurosurgical resection. Transcription rate of following CAZ proteins was measured via qPCR: SNAP25, VAMP1, VAMP2, SYT1, PCLO, BSN, STX1A. To examine amount of neuronal tissue TUBB3 and for glial fraction GFAP were quantified. A medulloblastoma cell line (DAOY) was furthermore analyzed to evaluate origin of high expressed proteins. Medulloblastoma showed high expression of PCLO (pilocytic astrocytoma vs. medulloblastoma p=0.0126) and STX1A (pilocytic astrocytoma vs. medulloblastoma p=0.0006) compared to. Likewise a high transcriptional level of TUBB3 could be seen with significance to pilocytic astrocytoma (2.2 ± 1.4 vs. 0.2 ± 0.17; p = 0.0018), which could indicate a high amount of neuronal tissue in given medulloblastoma samples. To rule out a causal link between high proportion of neuronal tissue and high CAZ expression, a paediatric medulloblastoma cell line was analysed. High expression of PCLO and STX1A in absence of TUBB3 was shown (3.8 and 2.01 vs. 0.059), indicating endogenous expression of CAZ proteins in medulloblastoma.
CNSC-11. INVESTIGATION OF GLIOBLASTOMA NEURON-TUMOR NETWORKS WITH RABIES-BASED RETROGRADE TRACING
Authors: Tetzlaff Svenja K , Reyhan Ekin , Bengtson C Peter , Schroers Julian , Wagner Julia , Schubert Marc C , Layer Nikolas , Puschhof Maria C , Faymonville Anton J , Drewa Nina , Pramatarov Rangel L , Wissmann Niklas , Alhalabi Obada , Heuer Alina , Sivapalan Nirosan , Campos Joaquín , Boztepe Berin , Scheck Jonas G , Villa Giulia , Schröter Manuel , Sahm Felix , Forsberg-Nilsson Karin , Breckwoldt Michael O , Acuna Claudio , Suchorska Bogdana , Heiland Dieter Henrik , Saez-Rodriguez Julio , Venkataramani Varun
Published: November 2024

Glioblastomas are primary brain tumors known for their whole-brain invasion and high therapeutic resistance. In previous studies, neuron-to-glioma synapses have been shown to promote glioblastoma progression. A deep characterization of this communication and of tumor-connected neurons has not been possible due to technological limitations. We adapted a rabies virus-based retrograde tracing approach to investigate and manipulate neuron-tumor networks. Interestingly, we found that glioblastoma cells rapidly integrated into neural circuits across the brain, engaging with distal neurons of diverse subtypes in very early stages of tumor development. Beyond glutamatergic neurons, we identified cholinergic neurons as drivers of glioblastoma cell invasion. We revealed patient- and tumor cell state-dependent differences in the expression of synaptogenic genes which also correlated with neuron-tumor connectivity and tumor cell invasivity. Notably, radiotherapy led to increased neuron-tumor connectivity mediated via neuronal hyperexcitability. The anti-epileptic drug perampanel alongside radiotherapy mitigated this effect and enhanced treatment efficacy by simultaneous neuronal activity inhibition. Utilizing our rabies-based approach, we genetically ablated tumor-connected neurons leading to a significantly decreased tumor progression offering a potential novel therapeutic avenue. Taken together, we developed a framework for dedicated analysis of multicellular neuron-tumor networks and propose our methodology as a versatile and adaptable approach to tackle glioblastoma.
CNSC-19. ISCHEMIC STROKE DRIVES GLIOMA PROGRESSION BY REMODELING TUMOR-ASSOCIATED ASTROCYTES
Authors: Ye Qi , Madamba Christine , Choy Tiffany , Spjut Catalina , Harmanci Akdes Serin , Khatri Latha , Yalamanchili Hari Krishna , Rao Ganesh , Deneen Benjamin , Lee Hyun Kyoung
Published: November 2024

Ischemic stroke and glioma are two deadly neurological disorders worldwide. Recent epidemiological studies reveal an increased risk of brain tumors, notably glioma, in patients with a history of stroke, resulting in a 10% co-occurrence. Comparative transcriptome analyses of brain samples collected from patients with common neurological disorders show that glioma is particularly enriched with stroke-associated gene signatures, especially in pathways related to their shared pathological features. These findings suggest a stroke-glioma interrelationship; however, it remains unknown how stroke alters the brain microenvironment to drive tumor progression. Here, we induced photothrombotic stroke in three mouse glioma models recapitulating multiple aspects of human glioma. Across all glioma models, we consistently observed that stroke increases tumor proliferation and infiltration towards stroke-affected regions, accompanied by reduced survival compared to sham control groups. Further analyses using single-cell RNA sequencing and spatial transcriptomic profiling in our stroke-glioma models reveal pronounced stroke-induced glioma microenvironment changes, among which tumor-associated astrocytes (TAAs) are most dramatically remodeled. Remarkably, we identified a unique stroke-induced astrocyte (SAA) at the tumor leading edge of the stroke-glioma group, characterized by diminished physiological astrocyte signatures and increased chromosomal and metabolic reprogramming. Among the top differentially expressed genes in SAA compared with TAA, the sodium-bicarbonate cotransporter Slc4a4 is interesting due to its enriched expression in TAA in both human and mouse gliomas, and it is significantly down-regulated at the infiltrating tumor edge. Consequently, we examine whether restoring astrocytic Slc4a4 expression rescues stroke-induced glioma progression. We found that astrocytic Slc4a4 overexpression reduces glioma growth and infiltration, accompanied by extended astroglial scar formation. Collectively, our study demonstrates that a subset of TAAs induced by stroke exacerbates glioma pathology, highlighting an indispensable astrocytic contribution to the stroke-glioma interaction.
CNSC-23. CROSSTALK BETWEEN STROKE AND GLIOMA: ISCHEMIA-INDUCED NEURONAL ACTIVATION ON GLIOMA INFILTRATION
Authors: Madamba Christine , Ye Qi , Lee Hyun Kyoung
Published: November 2024

Glioblastoma (GBM) is an aggressive primary brain tumor associated with dismal survival rates. GBM is difficult to treat due to its ability to invade neighboring brain regions, rendering complete surgical resection nearly impossible. Throughout tumor progression, several pathological changes occur in the tumor microenvironment (TME) including increased neuronal hyperactivity. Interestingly, these pathological features also occur in stroke, a leading global cause of death and disease burden. Clinical evidence from large cohort studies reveals a 10% risk of brain tumor development in stroke patients, suggesting a link between these two diseases. However, the intricacies of their association and whether stroke poses a long-term risk for GBM is unclear. To investigate this, we have developed innovative stroke-glioma mouse models to recapitulate and delineate the interrelationship between these two diseases. Our data using these models indicate a substantial increase in tumor growth and infiltration towards the infarct using both human GBM-patient derived glioma cells in immunodeficient mice as well as in immunocompetent de novo mouse GBM. Further, spatial manipulation of stroke and glioma induction revealed that glioma cells preferentially invade the contralateral hemisphere towards the stroke lesion compared to control. This suggests stroke-induced changes may trigger glioma cell infiltration. Histological analysis of the TME shows increased neuronal activity specifically excitatory neuron synaptic marker expression in the leading edge of glioma post-stroke compared to control. Overall, stroke induction may promote tumor growth and infiltration by modulating the TME through increasing excitatory neuronal activation. Together, this study aims to deepen our understanding of the influence of stroke on gliomas, paving the way for invaluable insights essential for identifying at-risk patients and the development of potential treatments for affected patients.
CNSC-34. SURGICAL INTERVENTION ASSOCIATION WITH THE DEVELOPMENT OF SUBSEQUENT DISSEMINATION IN CHILDHOOD DIFFUSE INTRINSIC PONTINE GLIOMAS (DIPG)
Authors: Bashir Shoaib , Lai Mingyao , Cai Linbo
Published: November 2024

BACKGROUND

Diffuse intrinsic pontine glioma (DIPG) is one of the most aggressive pediatric central nervous system tumors, and currently, there are no curative treatment options available. With the increasing application of molecular diagnostics, more and more DIPG patients are recommended to undergo surgery; however, its correlation with dissemination needs to be better understood. Hence, we conducted this cohort to analyze the predictors of subsequent metastasis in pediatric DIPGs.

METHODS

The final analysis included 142 pediatric (age ≤ 12) DIPG patients treated at Sanjiu Brain Hospital between January 2017 and September 2023. The data were retrospectively collected following the initial diagnosis. Patients were followed up for 6 months. The primary endpoint was the occurrence of subsequent metastasis. Univariable and multivariable logistic regression analyses were utilized to identify statistically significant predictors of subsequent dissemination. All statistical assessments were two-tailed, and only P < 0.05 was deemed to be statistically significant.

RESULTS

Among 142 patients, 14(9.9%) developed metastasis within the follow-up time. There were 77(54.2%) males and 65(45.8%) females. The median age was 7 years (ranging 1 - 12 years). The overall cohort demonstrated that surgery was the only predictor of dissemination both in univariable (OR 4.567, 95%CI 1.351 – 20.901, P = 0.024) and multivariable (OR 5.501, 95%CI 1.560 – 26.105, P = 0.014) analyses. However, subgroup analysis involving patients who received surgical intervention showed that biopsy was not superior nor inferior to resection in terms of relative risk for subsequent dissemination (16.7% vs. 15.8%).

CONCLUSION

Surgical intervention increases the relative risk of dissemination occurrence to four times more than those who did not receive surgery. Surgical intervention is crucial given the potential of molecular analysis leading to improved therapeutic options. Nonetheless, patients should be informed about the risks associated with surgery, including subsequent metastasis.
CNSC-35. TEMOZOLOMIDE POTENTIALLY POSTPONES THE DEVELOPMENT OF SUBSEQUENT METASTASES IN PEDIATRIC DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG) PATIENTS
Authors: Bashir Shoaib , Lai Mingyao , Cai Linbo
Published: November 2024

OBJECTIVE

Surgical intervention is thought to increase the likelihood of subsequent dissemination in diffuse intrinsic pontine glioma (DIPG) patients. However, there is no study evaluating the factors influencing the timing of metastasis development. Hence, the present analysis was conducted to shed light on factors associated with subsequent dissemination timing.

METHODS

This analysis included 28 pediatric (age≤12) DIPG cases with metastasis treated at Sanjiu Brain Hospital between June 1, 2017 and June 30, 2023. The clinical data were retrospectively collected following the initial diagnosis. The diagnosis was established by typical imaging features of DIPG. The same three radiologists analyzed the imaging data independently. Time to subsequent metastasis was estimated using Kaplan–Meier analysis, and a log-rank test evaluated the differences between groups.

RESULTS

Of 28 patients, 13 (46.4%) were males and 15 were females. 23 (82.1%) underwent surgical intervention, while 5 (17.9%) did not receive surgery. The patients’ median age was 7 years (2-12 yrs.). The Kaplan-Meier method showed that the median time to metastasis was 5.8 months (95%CI 4.2-9.1). The log-rank test demonstrated that adjuvant temozolomide was the only variable that could significantly delay metastasis in the pediatric DIPG population (P=0.03). The median time to metastasis from the day of initial diagnosis for those who received adjuvant temozolomide was 6.8 months (95%CI 5-10.7) vs. 3 months for those who did not receive adjuvant temozolomide (95%CI 2.3-NA). Sex, age, surgical intervention, and concurrent irradiation and temozolomide were not associated with metastasis timing.

CONCLUSION

Adjuvant temozolomide administration might benefit DIPG patients by delaying metastasis, especially in those who are at higher risk for subsequent metastasis, such as those who underwent surgical intervention. However, prospective studies are warranted to confirm these results.
CNSC-36. REGULATION OF CELL FATE IN PAEDIATRIC HIGH-GRADE GLIOMA BY THE HOMEOBOX TRANSCRIPTION FACTOR DLX2
Authors: Furst Liam , Roussel Enola , Leung Ryan , George Ankita , Li Jason , Best Sarah , Whittle James , Cain Jason , Firestein Ron , Faux Maree , Eisenstat David
Published: November 2024

Paediatric high-grade gliomas (pHGG) are nearly uniformly fatal cancers that arise predominantly in children and adolescents and encompass Diffuse Midline Glioma (DMG) and Diffuse Hemispheric Glioma (DHG). Most patients harbour mutations in histone variants H3.1 or H3.3, resulting in global epigenetic dysregulation and a stalled oligodendroglial progenitor (OPC) or GABAergic interneuron progenitor (IP) fate for DMG and DHG, respectively. DLX2, a homeobox transcription factor, represses OPC fate and promotes IP cell fate and migration during early neurogenesis. Our lab has shown that Dlx2 binds to and regulates the promoters of Gad1/Gad2, as well as early (Olig2, Nkx2.2) and late (Myt1, Plp1) genes required for OPC differentiation in vivo. Co-expression of Dlx2 with these target sequences reduces reporter gene expression in vitro and Dlx1/2 double knockout mice exhibit increased expression of these OPC markers in vivo. Transient overexpression of a Dlx2-GFP construct in murine DMG cells led to significant IP marker increase (Gad1/2), decrease of OPC markers (Olig2, Nkx2.2) and global restoration of H3K27me3. Additionally, decreased proliferation, colony growth, invasion and migration were observed in vitro. To translate these findings in human pHGG, analysis of a bulk RNA-seq database of 62 patient-derived pHGG cell lines revealed an inverse relationship between DLX2 and OLIG2. DLX2 was knocked out of DLX2high/OLIG2low DHG cell lines using CRISPR-Cas9, and overexpressed in DLX2low/OLIG2high DMG cell lines using a DLX2-mCherry overexpression construct. Evaluation of cell fate markers and epigenetic marks will be presented. Changes in migration, invasion, and proliferation in vitro will also be presented, in addition to changes in tumour growth using a neonatal xenograft murine model in vivo. Manipulation of DLX2 in pHGG provides a model for investigating the link between the factors that control cell fate decisions in the developing brain and the aberrant differentiation state in pHGG.
CNSC-38. INFLUENCE OF AGE, IMMUNOREGULATORY IDO, AND IMMUNOTHERAPY ON THE MICROBIOME IN MICE WITH AN EXPERIMENTAL BRAIN TUMOR
Authors: Zhai Lijie , Shrestha Akriti , Lauing Kristen , Penco-Campillo Manon , Ojo Oluwatomilayo , Bommi Prashant , Koch Taylor , Hatton Kyla , McCusker Robert , Anderson Douglas , Prabhu Vikram , Thakkar Jigisha , Allen Jacob , Wainwright Derek
Published: November 2024

OBJECTIVE

This study aimed to determine how IDO and subject age impact the gut microbiome and microbial metabolites during immunotherapy for glioblastoma (GBM).

METHODS

Serum and colon contents were collected from young 16-20- or older adult 92-118-week-old wild-type (WT; C57BL/6), IDO knockout (IDOKO), and IDO enzyme null (H350A) mice analyzed for 16S rRNA gut microbiome composition and microbial-derived aromatic amino acid metabolites via LC/MS/MS. Fecal samples from young 7-8 or older adult 81-85 week-old WT mice with intracranial GL261 brain tumors treated with or without brain radiation (RT) and PD-1 mAb were also analyzed.

RESULTS

Young and old IDOKO and H350A mice demonstrated a unique gut microbiome signature with an elevated abundance of Bifidobacterium and Helicobacter (p<0.05) and a reduced abundance of Ventriosum and Sireaum compared to WT mice (p<0.001). Prevotellaceae, Muribaculum, Alistipes, Enterohabdus, Clostridia, and Akkermansia were different in IDOKO and H350A mice compared to WT - but only in old mice. Serum aryl-lactates including phenyllactate, indolelacatate, and 4-hydroxyphenyllactate were increased in IDOKO mice compared to WT and H350A mice (p<0.001) – again, only in old mice. Older adult WT mice with GL261 showed lower fecal aryl-lactates compared to younger counterparts. Treatment with RT + PD-1 mAb decreased phenyllactate levels in old but not young mice with GL261 (p<0.05).

CONCLUSIONS

There are IDO enzyme- and non-enzyme-dependent effects on gut microbiota composition and bioactive microbial aromatic amino acid metabolites. These data warrant further investigation into how microbial metabolism affects immunotherapy efficacy and brain tumor survival across the lifespan.
CNSC-47. SENOLYTICS ERADICATE SENESCENT MICROGLIA IN THE BRAIN PARENCHYMA AND IMPROVE SURVIVAL IN OLDER ADULT MICE WITH GLIOBLASTOMA
Authors: Penco-Campillo Manon , Zhai Lijie , Bommi Prashant , Ojo Patience , Lauing Kristen L , Sanchez-Gomez Pilar , Anderson Douglas , Prabhu Vikram , Thakkar Jigisha , Lukas Rimas V , Wainwright Derek A
Published: November 2024

BACKGROUND

Glioblastoma (GBM) is the most common aggressive primary malignant brain tumor in adults with a poor median survival rate. Despite the aggressive standard of care treatment combining surgical resection, chemo-, and radio-therapy, the median overall survival (OS) is only ~15-18 months. Progressively increasing subject age is inversely associated with GBM patient OS such that older adults tend to have significantly worse survival outcomes compared to younger counterparts. Senescent cells accumulate in the body during progressive aging and contribute to worse outcomes in older adult mice with GBM. Senolytics are pharmacologics that cause senescent cells to undergo cell death.

OBJECTIVE

To comprehensively profile the treatment effect of senolytics combined with or without immunotherapy in mice with GBM across the lifespan.

METHODS

Young 7-9- and older adult 97-104-week-old wild-type (WT; C57BL/6) and 110-130-week-old INK-ATTAC mice with or without intracranial SB28 cells were treated with or without brain radiation (RT), PD-1 mAb, and an IDO enzyme inhibitor with the senolytics, dasatinib + quercetin, or the AP compound that induces p16INK4A+ senescent cell death in INK-ATTAC mice (n=5/group). The quantification of beta-galactosidase positive cells by flow cytometry was performed on brain-resident neurons, astrocytes, oligodendrocytes, microglia, as well as dendritic cells, macrophages, neutrophils, T cells in the tumor and non-tumor bulk mass. Overall survival was also evaluated.

RESULTS

Senolytics or AP compound treatment both decrease beta-galactosidase positive microglia in the older adult brain with GBM (p<0.05). Combining radio- and immuno-therapy with senolytics improves overall survival of older adult mice with intracranial GBM (p<0.05).

CONCLUSIONS

Our ongoing work aims to understand how senescent microglia affect neuronal health and function in the older adult brain with GBM.

KEYWORDS

Glioma, senescence, senolytic.
CNSC-52. OLIGODENDROGLIOMA SPATIAL TRANSCRIPTOMIC SEQUENCING REVEALS THERAPY-DEPENDENT EVOLUTION OVER TIME
Authors: Mirchia Kanish , Young Jacob , Nguyen Minh , Vasudevan Harish , de Groot John , Raleigh David
Published: November 2024

Oligodendroglioma evolution is incompletely understood. Here we analyze serial oligodendroglioma samples to define genomic and cellular mechanisms underlying treatment resistance. RNA sequencing was performed on 53,406 spatial transcriptomes from 31 oligodendrogliomas (IDH mutant, 1p/19q-codeleted) that were resected from 16 patients. There were 15 CNS WHO grade 2 and 16 grade 3 oligodendrogliomas, which were stratified for temporal progression across grades (n=5 grade 2 to 2, n=5 grade 2 to 3, n=6 grade 3 to 3) and treatments between serial resections (n=2 TMZ/RT, n=2 TMZ, n=1 mTOR inhibition, n=1 IDH inhibition, n=10 surgical monotherapy). Spatial transcriptomic clusters were defined using cell signature gene sets, cell cycle analysis, differentially expressed marker genes, immunohistochemistry, spatial copy number alterations (CNAs), and deconvolution of 18,628 oligodendroglioma single-cell transcriptomes from 16 independent patients. Specificity was tested using immunofluorescence on independent oligodendrogliomas that did not recur after surgical monotherapy (n=8 samples, median follow-up 8.4 years) and spatial transcriptomic sequencing on 8 matched-paired astrocytomas from 4 patients. Integrated uniform manifold approximation and projection revealed a proneural/NPC-like cluster that was enriched in grade 3 oligodendroglioma samples and represented the starting point in oligodendroglioma lineage differentiation using RNA velocity, Monocle, and subclonal spatiotemporal CNA evolution. Comparison across treatment regimens showed (1) enrichment of the proneural/NPC-like cluster in recurrent versus primary tumors that were treated with surgical monotherapy, (2) enrichment of a proneural/OPC-like cluster and depletion of an oligodendrocyte-like cluster after TMZ/RT, (3) enrichment of proneural/NPC-like and immediate-early response clusters after TMZ/RT, (4) enrichment of the oligodendrocyte-like cluster following mTOR inhibition, and (5) enrichment of cancer associated fibroblasts (CAFs) following IDH inhibition. These data show the spatiotemporal landscape of oligodendroglioma is associated with branched lineage differentiation that is modified by postoperative therapy, and suggest that therapy-dependent druggable dependencies may exist to treat oligodendrogliomas that are resistant to standard interventions.
CNSC-55. UNCOVERING THE ROLE OF COLLAGEN EXTRACELLULAR MATRIX IN GLIOBLASTOMA BRAIN MICROENVIRONMENT TRANSFORMATION
Authors: Hashemi Melika , Selvam Durgadevi , Hale Reid J , Shockley Katelynn , Zhyrgalbekovna Ailin , Comba Andrea
Published: November 2024

Glioblastoma (GBM) is a highly malignant brain tumor characterized by diffuse infiltration and significant heterogeneity, without effective treatment. Mesenchymal-like (MES) glioma cells drive tumor aggression by promoting brain invasion and tumor microenvironment remodeling. Previous spatial transcriptomic analyses identified Collagen, particularly COL1A, as a key extracellular matrix (ECM) component, enriched in MES areas termed oncostreams. Depletion of COL1A1 disrupted oncostreams, influencing the tumor microenvironment to support cell survival, and migration. Reactive astrocytes and macrophages, essential components of the brain microenvironment, impact glioma progression. However, the interplay between glioma-secreted collagen and the brain microenvironment remains poorly understood. To elucidate this, we generated orthotopic mouse glioma models with high-collagen (NPD) and low-collagen (NPDshCol1A1). Our data revealed that downregulation of COL1A1 in glioma cells alters the abundance and spatial distribution of reactive astrocytes and macrophages/microglia. Immunofluorescence and flow cytometry analysis showed that tumors with low-collagen had decreased GFAP+ reactive astrocyte cells at the invasive edge and perivascular niche compared to high-collagen gliomas. Moreover, our results shows that high collagen levels may activate astrocytes through distant communication, as evidenced by the higher presence of reactive astrocytes in the contralateral cortex of NPD tumors. However, low-collagen tumors exhibited an increase in astrocytes (GFAP+) in the tumor core. Furthermore, high-collagen gliomas demonstrated increased macrophage infiltration, promoting an immunosuppressive environment. Using multiplex immunohistochemistry assays, we observed that reactive astrocytes along the invasive tumor edge were associated with glioma cells expressing elevated levels of COL1A1 and TGF-β ligand. In summary, our results show that glioma cell-expressed COL1A1 promotes the activation of peritumoral and perivascular brain-resident astrocytes and macrophages. The interactions of reactive astrocyte with glioma cells enriched in collagen form a feedback loop that enhances tumor invasion and vascular proliferation, suggesting that targeting the ECM-astrocyte interactions could disrupt these processes and offer a therapeutic avenue for GBM.
CNSC-57. THE ROLE OF NEURON-TO-GLIOMA SYNAPTIC COMMUNICATION IN THERAPEUTIC RESISTANCE
Authors: Tetzlaff Svenja K , Reyhan Ekin , Bengtson C Peter , Layer Nikolas , Faymonville Anton J , Heuer Alina , Venkataramani Varun
Published: November 2024

Glioblastomas, primary brain tumors known for their extensive brain colonization and high therapeutic resistance, pose significant treatment challenges. Recent research has revealed that glioblastoma cells can form functional multicellular networks both with themselves, surrounding astrocytes and neurons. However, the investigation of the glioblastoma neuronal connectome has been limited by a lack of suitable methodologies. In this study, we utilized an adapted rabies-based retrograde tracing approach to characterize tumor-connected neurons and examine the neuronal connectome of the tumor in the context of therapy resistance. Our initial findings demonstrated that radiotherapy induces hyperexcitability in tumor-connected neurons, as shown by patch-clamp electrophysiology. This hyperexcitability was associated with an increase in neuron-tumor connectivity post-irradiation. To mitigate this increased neuronal input to therapy-resistant glioblastoma cells, we combined radiotherapy with the anti-epileptic drug perampanel. This combination therapy, which inhibits overall neuronal activity while delivering tumor cell-toxic photon irradiation, proved significantly more effective in reducing the number of therapy-resistant tumor cells. In summary, we employed a novel methodology to investigate the role of the neuronal tumor connectome in therapeutic resistance, identifying tumor-connected neurons as a potential target for improving glioblastoma treatment.
CNSC-61. NEURONAL-ACTIVITY DEPENDENT MECHANISMS OF SMALL CELL LUNG CANCER PATHOGENESIS
Authors: Savchuk Solomiia , Wang Wengang , Gentry Kaylee , Carleton Elana , Biagi Carlos , Yalçın Belgin , Ni Lijun , Farnsworth Hannah , Davis Rachel , Liu Yin , Acosta-Alvarez Lehi , Hartmann Griffin , Pavarino Elisa , LaBelle Jenna , Toland Angus , Woo Pamelyn , Qu Fangfei , Filbin Mariella , Krasnow Mark , Ligon Keith , Sage Julien , Sabatini Bernardo , Monje Michelle , Venkatesh Humsa
Published: November 2024

Neural activity is increasingly recognized as a crucial regulator of cancer growth. In the brain, neuronal activity robustly influences glioma growth both through paracrine mechanisms and through electrochemical integration of malignant cells into neural circuitry via neuron-to-glioma synapses. Outside of the CNS, innervation of tumors such as prostate, breast, pancreatic, and gastrointestinal cancers by peripheral nerves similarly regulates cancer progression. However, the extent to which the nervous system regulates lung cancer progression, either in the lung or when metastatic to the brain, is less well understood. Small cell lung cancer (SCLC) is a lethal high-grade neuroendocrine tumor that exhibits a strong propensity to metastasize to the brain. Here we demonstrate that SCLC cells in the brain co-opt neuronal activity-regulated mechanisms to stimulate growth and progression. With in vivo optogenetic stimulation, we show that glutamatergic and GABAergic cortical neuronal activity each drive proliferation of SCLC through both paracrine and synaptic neuron-cancer interactions. In the brain, SCLC cells form bona fide neuron-to-SCLC synapses evident on immunoelectron microscopy for the first time for non-brain derived malignancy. Using electrophysiology and two-photon calcium imaging, we find that SCLC cells exhibit depolarizing currents with consequent calcium transients in response to neuronal activity. SCLC cell membrane depolarization is sufficient to promote the growth of intracranial tumors. We also demonstrate reciprocal effects of SCLC on neurons, manifesting as increased neuronal synaptogenesis and elevated field potentials in regions of the tumor. Finally, in the lung, vagus nerve transection markedly inhibits primary lung tumor formation and development and awards survival benefit in spontaneous genetic SCLC model, highlighting a critical role for innervation in overall SCLC growth. Taken together, these studies illustrate that neuronal activity plays a crucial role in dictating SCLC pathogenesis in both the lung and the brain.
CCRG-04. RIBOCICLIB RESPONSIVE MENINGIOMA IN THE TREATMENT OF BREAST CANCER
Authors: Schipani Elke , Cathcart-Rake Elizabeth , Gilbertson Julie , Lanzino Giuseppe , Sener Ugur
Published: November 2024

BACKGROUND

Meningiomas are the most common primary intracranial tumors, typically managed with surgical resection and/or radiation therapy. Systemic therapy options are limited and reserved for cases refractory to conventional interventions. Cyclin dependent kinase (CDK) proteins are key cell cycle regulators. CDK inhibitors are clinically available, approved for treatment of breast cancer and in clinical trials for meningioma.

METHODS

We present a case where a patient with incidentally-discovered intracranial meningioma undergoing CDK inhibitor therapy with ribociclib for breast cancer experienced a radiographic response.

RESULTS

A 73-year-old female was diagnosed with estrogen receptor (ER) positive, progesterone receptor (PR) positive, HER2 negative metastatic invasive ductal carcinoma of the breast. She was treated with estrogen receptor antagonist fulvestrant and CDK 4/6 inhibitor ribociclib. MRI of the brain performed for disease staging demonstrated an extraaxial, dural-based, homogenously enhancing mass along the left posterior petrous ridge consistent with a meningioma. Two-month interval scan demonstrated a marginal decrease in size of the mass (15.6x18.3 mm to 15.4x17.5 mm). Systemic disease related to breast cancer concurrently improved. Two years later, with ongoing fulvestrant and ribociclib therapy, a repeat MRI brain demonstrated further decrease in size of the meningioma (13.4x16.8 mm).

CONCLUSIONS

Hormonally-directed therapies previously demonstrated limited benefit for meningiomas despite PR/ER positivity reported for these tumors. However, CDK 4/6 inhibitors abemaciclib and ribociclib have demonstrated activity in treatment of recurrent grade 2/3 meningiomas. The radiographic response noted in our case suggests there may be a role for systemic therapy even in treatment-naive cases that may not be amenable to surgical resection or radiation therapy.
CSIG-08. AGGRESSIVE HIGH-GRADE NF2 MUTANT MENINGIOMAS DOWNREGULATE ONCOGENIC YAP SIGNALING VIA THE UPREGULATION OF VGLL4 AND FAT3/4
Authors: Parrish Abigail , Arora Sonali , Thirimanne H Nayanga , Rudoy Dmytro , Schmid Sebastian , Sievers Philipp , Sahm Felix , Holland Eric , Szulzewsky Frank
Published: November 2024

Meningiomas are the most common primary brain tumors in adults. Although generally benign, a subset is of higher grade, shows aggressive growth behavior and recurs even after multiple surgeries. Around half of all meningiomas harbor inactivating mutations in NF2. While benign low-grade NF2 mutant meningiomas exhibit few genetic events in addition to NF2 inactivation, aggressive high-grade NF2 mutant meningiomas frequently harbor a highly aberrant genome. We and others have previously shown that NF2 inactivation leads to YAP1 activation and that YAP1 acts as the pivotal oncogenic driver in benign NF2 mutant meningiomas. Using bulk and single-cell RNA-Seq data from a large cohort of human meningiomas, we show that aggressive NF2 mutant meningiomas harbor decreased levels YAP1 activity compared to their benign counterparts. Furthermore, decreased expression levels of YAP target genes are significantly associated with an increased risk of recurrence. We then identify the increased expression of the YAP1 competitor VGLL4 as well as the YAP1 upstream regulators FAT3/4 as a potential mechanism for the downregulation of YAP activity in aggressive NF2 mutant meningiomas. High expression of these genes is significantly associated with an increased risk of recurrence. In vitro, overexpression of VGLL4 resulted in the downregulation of YAP activity in benign NF2 mutant meningioma cells, confirming the direct link between VGLL4 expression and decreased levels of YAP activity observed in aggressive NF2 mutant meningiomas. Our results shed new insight on the biology of benign and aggressive NF2 mutant meningiomas and may have important implications for the efficacy of therapies targeting oncogenic YAP1 in NF2 mutant meningiomas.
CSIG-10. DEFINING THE ROLE OF EZHIP ON CHROMOSOMAL INSTABILITY IN EPENDYMOMA
Authors: Faruck Lukmanul Hakkim
Published: November 2024

Diffuse Midline Gliomas (DMGs) are highly aggressive pediatric cancers with no effective treatments. Over 80% of DMGs harbor histone mutations, particularly H3.1 K27M, H3.3 K27M, and H3.3 G34R/V. These mutations impair the function of the Polycomb Repressive Complex 2 (PRC2), leading to reduced levels of H3K27me3. Overexpression of the EZHIP has been identified in ependymomas and DMGs. EZHIP overexpression is marked by widespread H3K27me3 loss and is mutually exclusive with histone mutations. EZHIP overexpression mimics the effects of the H3K27M mutation by reducing H3K27me3 levels. It is believed to inhibit the catalytic activity of EZH2 by binding to its SET domain, similar to the K27M mutant. Expression of EZHIP is tightly regulated and typically absent in most cell types. The transcriptional regulation of EZHIP is poorly understood; however, promoter hypermethylation is likely involved in regulating its expression. We investigate EZHIP’s role in DMG tumorigenesis, focusing on its regulation, impact on histone modifications, and chromosomal stability. Initial analyses have revealed transcription factor binding sites within the EZHIP promoter, including EGR2, SOX2, and ICP4, indicating that various transcription factors and viral infections might directly affect EZHIP expression. Utilizing RNA-Seq, we have identified both shared and unique transcriptomic alterations in DMG cells related to EZHIP expression and H3.3 K27M mutations. To study the role of EZHIP in tumorigenesis, we developed a mouse model expressing EZHIP-HA p2A PDFGB in RCAS-Nestin TVA mice. EZHIP expression induces high-grade tumors and significantly reduces survival. Our ongoing research suggests that EZHIP functions similarly to H3.3 K27M mutations in driving tumor growth, not only by reducing K27me3 but also through chromosomal missegregation. We aim to elucidate the full extent of EZHIP’s role in epigenetic control, histone post-translational modifications, chromosomal accessibility, and instability. Our findings will provide critical insights into the mechanisms underlying DMG tumorigenesis and potential therapeutic targets.
CSIG-15. ACROLEIN INDUCES THE MIR-30A-5P/NCAM AXIS VIA THE AKT/GSK3Β/Β-CATENIN PATHWAY, PROMOTING GLIOMA PROGRESSION
Authors: Chen Pin-Yuan , Liu Pei-Yu , Huang Chiungyin , Wang Hsiang-Tsui
Published: November 2024

Glioblastoma (GBM), the most aggressive brain tumor, exhibits resistance to treatment and thrives in low-oxygen (hypoxic) environments, leading to the accumulation of reactive oxygen species (ROS). Hypoxia activates the hypoxia-inducible factor (HIF)-1α pathway, enhancing tumor malignancy. Acrolein, a reactive aldehyde produced during lipid peroxidation in hypoxia, induces toxicity through DNA damage, inflammation, mitochondrial dysfunction, and oxidative stress. Our previous study found elevated acrolein levels in hypoxic glioma cells and linked acrolein-induced DNA damage (Acr-dG) with poor GBM prognosis. However, the role of acrolein in GBM progression remains unclear. This study aims to elucidate the impact of acrolein on GBM. In vitro experiments demonstrated acrolein production under hypoxia, which increased glioma cell migration and spheroid formation. RNA sequencing identified five affected pathways: cell adhesion molecules, PI3K-AKT signaling, ECM-receptor interaction, MAPK signaling, and neuroactive ligand-receptor interaction. Acrolein downregulated NCAM (neural cell adhesion molecule) via the miR-30a-5p-AKT-GSK3β/β-catenin axis in GBM cell lines and patient-derived cells. Overexpressing NCAM reduced cell migration and spheroid formation. Lower NCAM levels in GBM tissues correlated with poor patient survival. This study suggests the potential of NCAM as a therapeutic target for GBM and provides insights into early detection and treatment strategies for this malignancy.
CSIG-18. YAP/TAZ TARGET GENES MAY DETERMINE THE SELF-RENEWAL AND SURVIVAL OF GLIOBLASTOMA STEM CELLS
Authors: Ishan Mohamed , Oh Se-Yeong , Young Elizabeth , Hu Zhengang , Read Renee D
Published: November 2024

Glioblastoma, a neoplasm arising from neuro-glial stem/progenitor cells, is the most aggressive and lethal form of brain cancer, with a median survival of 14 months. Despite intensive treatments like surgery, radiation, and chemotherapy, recurrence is inevitable, underscoring the urgent need for new treatment strategies. Progress is limited by an incomplete understanding of the biological mechanisms that drive glioblastoma formation and progression, hindering the development of effective therapies. Key molecular pathways, particularly the receptor tyrosine kinases, such as EGFR, and their effector pathways play a critical role in the initiation and maintenance of glioblastoma. Our lab’s research using patient-derived glioblastoma neurospheres and mouse models has shown that the transcriptional co-activators YAP and TAZ are overexpressed downstream of EGFR activity in EGFR-amplified or mutant glioblastoma tumors. YAP/TAZ proteins interact with the TEAD family DNA-binding proteins to promote expression of transcriptional target genes, including SOX2, C-MYC, and EGFR itself in glioblastoma, creating a positive feedback loop that enhances tumor stem cell renewal, proliferation, and survival. Furthermore, our research has demonstrated that inhibiting YAP/TAZ activity with the drug Verteporfin induces apoptosis and promotes growth arrest in patient-derived EGFR-amplified/mutant glioblastoma models. Our findings highlight YAP/TAZ-TEAD as key mediators of glioblastoma stem cell (GSC) self-renewal and survival. Ongoing experiments aim to identify tumor cell-specific YAP/TAZ-TEAD transcriptional target genes predictive of response to YAP/TAZ inhibition in GSCs within EGFR-amplified glioblastomas. Our research seeks to uncover the epigenetic basis of YAP/TAZ dependencies and to determine which genes and cellular processes are critical for tumor stem cell survival, tumor progression, and sensitivity to YAP/TAZ inhibition. These target genes could serve as biomarkers for predicting therapeutic response to YAP/TAZ inhibitors in glioblastoma.