bluuebunny/crossref_metadata_2025_split huggingface dataset:
TMIC-77. UNVEILING THE DEPTHS: EXPLORING DIFFUSE MIDLINE GLIOMA, TUMORIGENESIS, AND RADIATION RESISTANCE
Authors: Patel Palak , Kukreja Bharti , Kalish Brian , Pajovic Sanja , Hawkins Cynthia 
Published: November 2023

Abstract
Diffuse Midline Glioma (DMG) is a highly aggressive form of brainstem cancer that primarily affects children, leading to a grim prognosis and limited treatment options. Despite extensive research efforts, many crucial aspects of DMG development and progression remain poorly understood. One significant knowledge gap lies in comprehending the invasive nature of DMG cells, which enables their escape from the primary tumor site and dissemination to other regions of the brain. Additionally, understanding the molecular basis that drives this invasive behavior is essential but remains largely unexplored, necessitating further investigation. To address these critical knowledge gaps, we have generated one of the largest single-cell multi-omic datasets ( &gt;300,000 cells) specifically focusing on pons development in humans and its relation to DMG. This dataset provides a valuable resource for investigating the intricacies of tumorigenesis and the development of resistance to radiation therapy. Comprehensive analyses of this dataset shed light on the molecular events driving DMG progression and radiation resistance, ultimately paving the way for the discovery of novel therapeutic targets and the development of innovative strategies to combat this devastating pediatric cancer. In summary, our study aims to deepen our understanding of DMG by elucidating the mechanisms associated with histone mutations, unraveling the invasive behavior of DMG cells, and exploring the factors contributing to radiation resistance. Through these endeavors, we hope to make significant advancements in the field and improve the outcomes for patients affected by DMG.
TMIC-81. DECODING THE ROLE OF MICROENVIRONMENT ON DISTINCT FAILURE PATTERNS OF MALIGNANT GLIOMAS
Authors: Choi Seung-Won , Rabadan Raul 
Published: November 2023

Abstract
Most malignant gliomas experience recurrence with distinct failure patterns. The spatial relationship between the primary and recurrent tumors usually represents the genomic distanc; however, the molecular backgrounds of these failure patterns have not been evaluated yet. Our aim was to investigate the molecular profiles underlying the distinct failure patterns of malignant gliomas. This study involved 272 malignant glioma patients, with transcriptomic data available for 166 of these cases. The failure pattern was defined according to the spatial relationship between the primary and recurrent pairs including local recurrence, remote recurrence, and leptomeningeal seeding. When the recurrent tumor exhibits more than one failure pattern simultaneously, we define this as a combined failure pattern. Local recurrence was the most frequent pattern, followed by combined failure pattern (62.9% & 22.8%, respectively). Multi-variate cox analysis showed that combined failure pattern was a significant prognostic factor (odds ratio= 3.34, p-value &lt; 0.001). We defined a genomic signature for malignant gliomas with a combined failure pattern (comb-GS) and validated its worse prognostic impact in other cohorts (GLASS, TCGA). Using public scRNA-seq data with regional annotation, we found that two distinct non-tumor components, immune and neuronal components, contributed to the development of the combined failure pattern. This finding was well correlated with the variability of comb-GS in different anatomic regions in IVY-gap dataset. In summary, this study demonstrated that both immune and neuronal components are involved in the progression of malignant gliomas. These two microenvironmental elements exhibit a shared negative clinical outcome, despite presenting distinct phenotype. To decipher the exact biological role of each component, experimental validation is necessary.
TMIC-84. A DEEP LEARNING-BASED METHOD FOR RAPID, PATIENT-SPECIFIC ASSAY OF MACROPHAGE INFILTRATION IN HIGH-GRADE GLIOMA USING LABEL-FREE STIMULATED RAMAN HISTOLOGY
Authors: Alber Daniel , Lock Emily , Sangwon Karl , Smith Andrew , Movahed-Ezazi Misha , Oermann Eric , Hollon Todd , Orringer Daniel 
Published: November 2023

Abstract

BACKGROUND
5-Aminolevulinic acid (5-ALA), the most widely used fluorophore in image-guided glioma surgery, identifies tumor-associated macrophages (TAM) in high-grade glioma (HGG) tissue. Infiltrating macrophages, the predominant immune cells in glioma, are highly implicated in tumor progression, recurrence, and treatment response – particularly in immunotherapy. Using a unique, paired dataset of label-free stimulated Raman histology (SRH) and two-photon microscopy (TPEF) images sharing one-to-one spatial resolution, we developed a deep-learning approach to automatically quantify TAM infiltration from intraoperatively acquired SRH images.

METHODS
We compiled a dataset of 906 paired whole-slide SRH/TPEF images from 79 patients with HGG. We first trained a pix2pix generative adversarial network to convert raw, label-free SRH into synthetic TPEF with identifiable macrophages. Next, we trained a MaskR-CNN model to locate and segment TAMs. The pix2pix network was trained using 5,531 hand-picked 300-by-300-pixel fields-of-view (FOV) best exemplifying TAMs. We used a human-in-the-loop approach to train the segmentation network on 1,000 hand-labeled FOVs.

RESULTS
Macrophage segmentation from purely histologic data was near-identical to the fluorescence-based ground truth, with a mean dice score of 90.3%. Predicted TAM density was highly correlated with r=0.735. Subgroup analyses of TAM density in 346,836 non-overlapping FOVs revealed significantly lower TAM density in IDH-mutant (p&lt; 0.01) and MGMT-hypermethylated (p=0.03) tumors. Our end-to-end algorithm uses fresh, unlabeled tissue specimens in the operating room and takes just three minutes to analyze whole-slide SRH images.

CONCLUSION
We demonstrate how deep neural networks can be used to rapidly and quantitatively evaluate macrophage infiltration in HGG in the operating room. Our software enables analysis of glioma patients’ tumor immune environment without immunohistochemistry or fluorescent labels, and may be leveraged to study the effects of immune-modulating therapies in the tumor microenvironment. Future work will focus on evaluating macrophage density and distribution as biomarkers for response to immunotherapies showing efficacy in glioma patients.
MODL-01. INTRACRANIAL TUMORS HIJACK THE MENINGEAL VENOLYMPHATIC NETWORK THROUGH VEGFR-2 SIGNALING
Authors: McGavern D , Ampie Leonel 
Published: November 2023

Abstract

INTRODUCTION
Glioblastoma and other intracranial neoplasms have been associated with breakdown of the blood brain barrier. Other protective CNS barriers have sparsely been studied in brain tumors. Here, we identify the ability of intracranial neoplasms to hijack the meningeal venolymphatic network, which is driven through VEGFR-2/VEGF-A signaling.

METHODS
C57BL/6J mice were stereotactically injected with syngeneic SB28 (glioblastoma) cell lines. Mice were treated with either isotype control or a VEGFR-2 inhibitor. Two-photon microscopy was used to visualize vascular cytoarchitecture and dynamics in vivo. Meningeal whole mounts, brains and spleens were also collected and analyzed by confocal microscopy and high parameter flow cytometry. Similar experiments were conducted with a PECAM-1 inhibitor to assess the role of endothelial cell crosstalk in venolymphatic expansion. Human dura mater from glioblastoma patients underwent multiplex immunohistochemistry to confirm the translatability of our findings.

RESULTS
Our imaging studies revealed that glioblastomas can generate an extensive de novo network of meningeal blood vessels and lymphatics both in mice and humans. Lymphatic vessels were often observed developing in parallel to the newly formed vasculature. Intravital two-photon microscopy further revealed that the peritumoral vascular bed in the meninges of mice was leaky, dysfunctional, and generated a hypoxic microenvironment. Importantly, inhibition of VEGFR signaling impeded formation of this faulty venolymphatic network, which slowed tumor growth, reduced peritumoral hypoxia, enhanced immune infiltration, and increased survival. PECAM-1 (CD31) inhibition had a similar effect on the tumor microenvironment, suggesting that endothelial cell crosstalk is required for glioblastomas to optimally invade the meninges.

CONCLUSION
Our results demonstrate that glioblastomas can invade the meninges and hijack the venolymphatic network through VEGFR-2 and PECAM-1 signaling. While VEGFR-2 is associated with angiogenesis, our data suggest that it may also have an important role in regulating the simultaneous development of de novo meningeal venous and lymphatic drainage during glioblastoma.
MODL-03. AN EX VIVO PLATFORM BASED ON ORGANOTYPIC BRAIN SLICE CULTURE FOR INFORMING PERSONALIZED BRAIN CANCER THERAPY
Authors: Zhang Xiaopei , Mann Breanna , Bell Noah , Adefolaju Adebimpe , Thang Morrent , Dasari Rajaneekar , Kanchi Krishna , Valdivia Alain , Yang Yang , Buckley Andrew , Lettry Vivien , Quinsey Carolyn , Rauf Yasmeen , Kram David , Cassidy Noah , Vaziri Cyrus , Corcoran David L , Rego Stephen , Jiang Yuchao , Graves Lee M , Dunn Denise , Floyd Scott , Baldwin Albert , Hingtgen Shawn , Satterlee Andrew B 
Published: November 2023

Abstract
While the improved classification of CNS tumors is already enhancing the scientific rigor of clinical brain cancer treatment guidelines, the impact of these integrated diagnoses based on histopathological features or molecular insight on precision oncology medicine has yet to demonstrate widespread clinical benefit. Patient tumor-derived cancer models, including patient tumor-derived cell lines, organoids, and explants, have provided practical models based on a patient’s individual tumor for effective therapeutic drugs. Importantly, patient tumor-derived organoids have shown potential to guide personalized care and optimize clinical outcomes by functionally predicting patient response to antitumor drugs prior to in vivo treatment. Our team has built an organotypic brain slice culture (OBSC)-based platform and multi-parametric algorithm that allows for the ex vivo engraftment, rapid treatment, and systemic analysis of resected patient brain tumor tissue. This OBSC platform has successfully supported engraftment of each patient tumor tested to this point, including high- and low-grade adult and pediatric tumor tissue. The established patient tumor-derived organoids show the ability to activate the endogenous astrocytes within OBSCs, which have been reported in brain tumor. Whole exome sequencing analysis showed that patient tumor tissue engrafted onto OBSCs maintained a significant genetic resemblance to their parent tumor, while tumor tissue expanded in vitro displayed a distinctly different DNA profile. Additionally, our algorithm calculates dose-response relationships of both tumor kill and normal brain tissue toxicity, generating summarized drug sensitivity scores based on therapeutic window and allowing us to normalize response profiles across a panel of FDA-approved and exploratory agents. Summarized patient tumor scores after OBSC treatment revealed positive associations to clinical outcomes, suggesting the OBSC platform can provide rapid, accurate, functional testing to ultimately guide patient care.
MODL-06. THE GUT MICROBIOTA OF BRAIN TUMOR PATIENTS CAN IMPACT IMMUNOTHERAPY EFFICACY IN A PRECLINICAL MODEL OF GLIOMA
Authors: Kim Donggeon , Sarvesh Sujith , Valbak Olivia , Backan Olivia , Chen Dongquan , Morrow Casey , Benvensite Etty , Nabors Burt , Bekal Mahesh , Dono Antonio , Esquenazi Yoshua , Forsyth Peter , Yu Hsiang-Hsuan Michael , Khushalani Nikhil , Egan Kathleen , McFarand Braden 
Published: November 2023

Abstract
Combination immune checkpoint inhibitors (ICI) can affect durable response in melanoma brain metastases (MBM) but have largely been ineffective for the treatment of glioblastoma (GBM), a primary brain tumor. Recent studies in animal models and humans have suggested that the microbe composition of the gut can influence the effectiveness of ICI in melanoma and other cancers. Our central hypothesis is that the gut microbiome can influence immunotherapy responsiveness for GBM patients. We obtained microbiome (stool) samples from GBM and MBM patients prior to beginning any treatment or surgical interventions. We then transplanted these microbiome samples into gnotobiotic mice to create humanized microbiome mice. We transplanted two GBM patients and two MBM patients microbiome samples to create 4 unique patient-derived humanized microbiome mouse lines (GBM1, GBM2, MBM1, and MBM2). Using 16s ribosomal RNA microbiome sequencing, we found that each patient-derived microbiome mouse line had a unique microbiome composition as measured by relative abundance and diversity of species. Mice from each line were then intracranially injected with GL261 murine glioma cells and treated with the ICI anti-PD-1 or isotype control. We found that MBM1 and GBM2 mice were resistant to anti-PD-1 and did not display prolonged survival with anti-PD-1 treatment. However, GBM1 and MBM2 mice were positive responders to anti-PD-1 and displayed significantly prolonged survival compared to isotype control. Additional microbiome sequencing analyses are ongoing that will reveal positive microbiome profiles among these patient-derived lines, and additional GBM and MBM patient-derived microbiome lines are being created and tested for immunotherapy efficacy. Ultimately, understanding how certain microbial communities can enhance the effectiveness of immunotherapy may lead to the development of new approaches that include modification or transplantation of microbe communities in GBM patients for increased therapeutic impact.
MODL-16. GLIOBLASTOMA GROWTH IS SHAPED BY INVASION ROUTE-SPECIFIC FUNCTIONAL SIGNATURES
Authors: Krona Cecilia , Rosén Emil , Kundu Soumi , Olausson Karl Holmberg , Larsson Ida , Elfineh Ludmila , Doroszko Milena , Elgendy Ramy , Wickström Johan , Jörnsten Rebecka , Nelander Sven 
Published: November 2023

Abstract
One of the defining features of glioblastomas (GBMs) is the capacity for invasive growth along multiple anatomical pathways in the brain. GBM is well-studied on a genetic and molecular level, but clinically relevant and experimentally tractable models of invasive growth are largely lacking. Here, we report an integrated study of patient-matched information, genomic- and molecular profiles with growth in mouse brains to expose treatments and biomarkers associated with glioblastoma invasion and recurrence. In total, 64 patient-derived cell lines (PDCLs) were injected into the striatum of n ≥ 4 mice each. The 45 tumor-forming PDCLs were each scored for 10 distinct growth characteristics (n = 182 mice). The repertoire of phenotypes was highly divergent, and our material included clear cases of perivascular route invasion, white matter route invasion, perineuronal satellitosis, and gliosarcoma. We explored if cellular pathways, monitored by RNA-sequencing, could account for these differences. GSEA highlighted a positive enrichment for highly proliferative proneural tumors characterized by Notch activation, neuronal signaling, and epigenetic gene regulatory programs in the tumor-initiating lines. Transcriptional signatures were also strongly predictive of route-specific invasion. Diffuse invasion was predominantly seen in classical-subtype PDCLs with astrocytic or outer radial glia-like signatures. Proneural PDCLs, in turn, grew as solid tumors with an invasive peripheral region around vasculature, and mesenchymal tumors were more demarcated. To explore the therapeutic implications of our findings, we used our data-driven method (TargetTranslator, Nat Comm 2020) to predict the drug vulnerabilities of different types of invasive glioblastoma. Defined GBM tumors with perivascular invasion are characterized by increased IGFR1, MAPK/ERK, PI3K/AKT/mTOR, and JAK2 signaling. Diffusively growing GBM tumors, on the other hand, depend more on Wnt/β-catenin signaling, neuronal signaling, and active inflammatory response. Using a sphere invasion assay, we confirm that targeting both PI3K- and Wnt signaling selectively reduces glioblastoma invasion, highlighting their therapeutic potential.
MODL-19. DEVELOPMENT OF A RECURRENT GLIOBLASTOMA MURINE MODEL FOLLOWING SURGICAL RESECTION: INVESTIGATING THE TUMOR-IMMUNE MICROENVIRONMENT TO EVALUATE NOVEL PERIOPERATIVE THERAPIES
Authors: Das Arabinda , Stephens Heather R , Mark Joe , Garrison Jeff , Sekerak Penny , Baraso Randy , McDonald Daniel G , Yazdani Milad , Welsh Cynthia A , Infinger Libby Kosnik , Eskandari Ramin , Vandergrift III William A , Varma Abhay K , Patel Sunil J , Cachia David , Zukas Alicia M , Lindhorst Scott M 
Published: November 2023

Abstract

BACKGROUND
Most glioblastoma (GBM) patients experience tumor recurrence following standard-of-care treatment which includes tumor resection, radiation, and chemotherapy with concomitant and adjuvant temozolomide. Currently, no murine surgical GBM resection models to evaluate novel therapies exist and understanding of postsurgical tumor microenvironment (TME) has yet to be fully elucidated in pre-clinical GBM models.

METHODS
GL261 GBM cells were orthotopically implanted in C57BL/6 mice on day 1. On day 14, tumor resection was performed using the NICO Murine Neuroscience System, an automated, intraoperative, pre-clinical surgical resection system designed to minimize damage to surrounding tissue thus preventing the need for animal sacrifice. Standard T2-MRI and Terason uSmart 3200T ultrasound system were used to analyze tumor size following resection and recurrent growth. Immunological and biochemical assays were performed to explore local TME.

RESULTS
We observed that surgically resected GL261 GBM mice survived 55 + 8 days whereas mice with unresected GBM survived 35 + 7 days following tumor implantation. This new preclinical surgical resection recurrent immunocompetent GBM (Sur-rGBM) model was used for analyzing TME. Our results demonstrated significant changes in TME, such as an increase in astrocytic activation (GFAP+), increased microglia/macrophage (CD11b+, and IBA-1+) infiltration to surrounding tissue, increase in M2 macrophage (TGM2+ and CCL22+) and NK regulatory cells (CDC 26 +), and increased angiogenesis (VEGF) in Sur-rGBM as compared to unresected GBM. We also observed increased proliferation (Ki-67) and upregulation of stem cell markers CD133, Nestin, and Olig2 at the protein level.

CONCLUSION
Our data demonstrated the upregulation of tumor-promoting activation factors in Sur-rGBM as compared to unresected GBM. Currently, the Sur-rGBM model does not fully resemble the entire treatment regimen offered to GBM patients. Thus, our future aim is to further refine this resection model and assess adjuvant therapies at different time points along disease progression without needing to sacrifice the animal for analysis of tissue.
MODL-20. PRECLINICAL MODELING OF LASER INTERSTITIAL THERMAL THERAPY IN MURINE BRAIN TUMORS FOR TRANSLATIONAL IMMUNO-ONCOLOGY
Authors: Haskell-Mendoza Aden , Wachsmuth Lucas , Tyc Richard , Fecci Peter 
Published: November 2023

Abstract

INTRODUCTION
Cytoreductive surgery is a cornerstone of management for intracranial tumors. However, resection may remove an important source of neoantigen. In the case of laser interstitial thermal therapy (LITT), ablated tumor remans in situ, allowing for an anti-tumor immune response. To characterize these phenomena, we developed a murine model of LITT for use with syngeneic brain tumor cell lines.

RESULTS
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METHODS
To establish anatomical boundaries for our ablation, we characterized our CT-2A glioma model on T2 MRI, selecting 10 days post-implantation for LITT based on lesion size. We simultaneously implanted a 400 μm laser fiber and thermocouple probe into the center and edge of the target volume, respectively, for simultaneous ablation and temperature monitoring. Using a clinical 1064 nm Nd:YAG laser, we first performed a dose titration of laser power/time in normal mouse brains, finding that doses above 1.5 W for 60s produced cavitary lesions with charring that resulted in death at 24h post-LITT. We therefore selected 1 W for 60s as a safe laser power dose in our tumor model. Ablations at this setting rapidly heated the lesion edge to a peak temperature of mean 43.79 ± 2.993 °C, sparing the surrounding brain. MRI imaging at 1, 3, and 7 days post-LITT revealed expansile T2 hyperintense lesions that resolved over time, with hemorrhage and necrosis on H&E. LITT increased survival to 28 from 25.5 days (vs sham, P = 0.0172).

CONCLUSIONS
Our model successfully recapitulates the essential clinical features of LITT: a cytoreductive survival benefit; lesion expansion on MRI; and focal necrosis with hemorrhagic vasculature on H&E. This model is well suited for study of LITT-adjunctive interventions and characterization of the immunobiology of hyperthermia.
MODL-21. INVESTIGATING THE PATHOGENIC MECHANISMS OF FOXR2-MUTATED PEDIATRIC BRAIN TUMOR USING A HUMAN-EMBRYONIC STEM CELL-BASED MODEL
Authors: Royston Hitomi , Emerson Miriam , Hampton Autumn , Funato Kosuke 
Published: November 2023

Abstract
FOXR2-activated CNS neuroblastoma is a recently identified subtype of brain tumor characterized by genomic rearrangements at the FOXR2 locus and elevated expression of the transcription factor FOXR2. However, the precise mechanisms underlying the tumorigenesis of this specific subtype, including the cell type of origin, are not fully understood. In this study, we established a new tumor model using human embryonic stem cells (hESCs) to determine the cell type of origin and the underlying pathogenic mechanisms. Expression profile analysis of patient tumors revealed increased expression of interneuronal marker genes, such as DLX1, NKX2.1, and SST (Somatostatin). Given that NKX2.1 and SST are markers for interneuronal cells originating from the Medial Ganglionic Eminence (MGE) in the ventral forebrain, we hypothesized that MGE-derived interneuronal progenitors are the cell type of origin. To test this hypothesis, we differentiated hESCs into MGE-type interneuronal progenitors using a chemically defined protocol, while using cortical excitatory neural progenitors as a control cell type. Subsequently, we overexpressed FOXR2 in these cell populations and analyzed the cellular phenotype. Our data showed that, in low density culture, FOXR2 overexpression in the MGE-type interneuronal progenitors led to a significantly greater increase in proliferation compared to the cortical progenitor cells, indicating a cell-type-specific effect of FOXR2. Our novel model holds great promise for elucidating the molecular mechanisms underlying the formation of FOXR2-activated CNS neuroblastoma and paving the way for the discovery of therapeutic targets and effective treatments for patients suffering from this devastating disease.