bluuebunny/crossref_metadata_2025_split huggingface dataset:
CNSC-25. NEURAL SIGNATURE OF GBM EXHIBITS SYNAPTOGENIC AND OPC-LIKE FEATURES AND INDEPENDENTLY PREDICTS PATIENT SURVIVAL
Authors: Drexler Richard , Khatri Robin , Sauvigny Thomas , Mohme Malte , Ryba Alice , Dührsen Lasse , Maire Cecile , Salviano-Silva Amanda , Lamszus Katrin , Westphal Manfred , Gempt Jens , Wefers Annika , Neumann Julia , Bode Helena , Hausmann Fabian , Huber Tobias , Bonn Stefan , Delev Daniel , Weber Katharina , Harter Patrick , Onken Julia , Vajkoczy Peter , Capper David , Wiestler Benedikt , Monje Michelle , Silverbush Dana , Hovestadt Volker , Suva Mario , Krishna Saritha , Hervey-Jumper Shawn , Schüller Ulrich , Heiland Dieter Henrik , Hänzelmann Sonja , Ricklefs Franz L 
Published: November 2023

Abstract
Interactions of neural cells with glioma cells drive tumor growth. In this study, we identified an epigenetically-defined, malignant neural signature of IDH-wildtype glioblastoma (GBM) that significantly influenced patients’ outcome. We used DNA methylation-based reference signatures of neural cells to deconvolve 1.058 primary patient GBM samples. Samples were classified based on the neural reference signature and annotated as low or high neural GBM. A high neural GBM was linked to hypomethylation of CpG sites associated with invasiveness, neuron-to-glioma-interactions, and transsynaptic signaling. Through spatially resolved, single cell transcriptomic and proteomic profiling, we discovered a correlation between the high neural signature and the upregulation of early development programs in OPC and NPC-like cells. These traits were accompanied by diminished immune infiltration and immunological response, further highlighting the distinctive neural-like nature of GBM. High neural GBM demonstrated increased connectivity as evidenced by magnetoencephalography and resting state magnet resonance imaging. Spatiotemporal tumor sampling showed a homogeneous and stable neural signature in newly diagnosed and recurrent GBM. In newly diagnosed GBM, a high neural signature correlated with decreased survival in 306 patients (median OS 15.0 versus 20.0 months, p&lt; 0.001). Patient-derived xenograft models corroborated the aggressive nature of high neural GBM, showing a significantly reduced median OS of 58 days compared to 73 days (p&lt; 0.01). These high neural GBM xenografts also exhibited an elevated tumor burden and an increase in neuron-glioma synapse formation. Consideration of the extent of resection showed a dependency on the neural subgroup as high neural GBM had an increased benefit from a complete contrast enhancing tumor removal when compared to low neural GBM. As a preoperative biomarker, the concentration of BDNF was increased in serum of high neural GBM patients (p &lt; 0.01). Overall, we present an epigenetically-defined malignant neural signature in GBM that is associated with an unfavorable patient survival.
CNSC-38. CHARACTERIZATION OF THE FUNCTIONAL RELEVANCE OF INTRA- AND INTERTUMORAL NETWORKS IN PRIMARY BREAST CANCER
Authors: Nürnberg Christina , Schrenk-Siemens Katrin , Würth Roberto , Trumpp Andreas , Mayer Chanté , Karreman Matthia , Pan Chenchen , Wick Wolfgang , Winkler Frank 
Published: November 2023

Abstract
Despite intensive efforts to improve current therapeutical strategies, breast cancer continues to be a life-shortening diagnosis for a significant number of affected women. Considering that the innervation density of breast cancers negatively correlates with the prognosis, the emerging field of Cancer Neuroscience, which deals with the reciprocal interactions between the nervous system and cancer cells, represents an attractive novel research direction. In fact, studies on breast cancer brain metastases have proven that the metastatic cells receive growth stimuli by hijacking healthy glutamatergic synapses. Beyond being capable of forming direct glutamatergic cancer-neuron synapses, primary brain tumor cells also connect to a multicellular intercommunicating network that contributes to therapy resistance. Whether similar mechanisms also apply to tumors outside the brain – accountable for the majority of cancer cases – remains unknown. Here, we aim at unraveling the functional role of intratumoral networks and the influence of (potential) direct primary breast cancer cell-neuron interactions. We hypothesize that purinergic signaling as a universal synaptic signaling mechanism enhances tumor growth. Through the application of ex vivo whole-organ tissue-clearing and nerve-labeling approaches, we noticed prevalent sensory and sympathetic innervation in the healthy and diseased murine mammary gland. Furthermore, we measured tumor cell proliferation rates in an in vitro model of primary murine sensory DRG-neurons co-cultured with breast cancer stem cells and compared these to monoculture controls. By implanting a mammary imaging window over the growing primary tumor, we longitudinally track the calcium activity of breast cancer cells in their natural microenvironment in the living mouse. We thereby are able to record co-activity of neighboring cells indicative of intratumoral network communication in primary breast cancers. Overall, our data support the existence of functional intra- and intertumoral breast cancer cell networks as an alternative therapeutical target. Future work needs to concentrate on unequivocally detecting direct neuron-cancer cell contacts.
CNSC-39. GENERATION AND CHARACTERIZATION OF LIVING ORGANOTYPIC BRAIN SLICE CULTURES AS A NOVEL PRE-CLINICAL MODEL FOR BRAIN CANCER
Authors: Dasari Rajaneekar , Mann Breanna , Zhang Xiaopei , Bell Noah , Adefolaju Adebimpe , Thang Morrent , 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
A challenge in cancer research is developing reproducible, reliable, and practical models which can capture the complexity of cancer development and treatment. The development of functional precision medicine platforms is emerging as a promising strategy for improving pre-clinical drug testing and guiding clinical decisions. We have developed an organotypic brain slice culture (OBSC) technology composed of intact multicellular tissue which can be rapidly used for spatiotemporal drug response testing. OBSCs are reproducibly generated from Sprague-Dawley rat pups and used as living tissue substrates to culture treat different tumor cell lines and uncultured patient brain tumor resection tissue. We evaluated OBSC quality and reproducibility throughout the study by using a propidium iodide nuclear permeability assay. This technique enabled a broad dynamic range to distinguish between healthy and unhealthy slices. In these studies, the rat pup age at the time of generation had an impact on OBSC quality and quantity, indicating that OBSCs should be generated from eight-day-old pups. We also found that optimal OBSCs were generated using improved methods for brain dissection and OBSC culture conditions, establishing our robust, standardized procedure for OBSC generation. Following this optimization period, we continued to conduct quality control analysis with 6 OBSCs per batch for reproducibility. We also conducted immunohistochemistry analysis immediately after slicing and concluded that morphology of neurons in OBSCs remained unchanged between day 0 and 4. In addition, the activation of astrocytes attenuates by day 4 but persists in macrophages/microglia, suggesting that the myeloid cells can phagocytose dead cells and debris in OBSCs. In summary, these results indicate that the OBSC platform may be an effective model that accelerates preclinical drug testing and directs drug development towards clinical evaluation.
CNSC-43. TARGETING NEURONAL EXCITABILITY FOR NF1 LOW-GRADE GLIOMA THERAPY
Authors: Anastasaki Corina , Chatterjee Jit , Gao Yunqing , Koleske Joshua P , Bozeman Stephanie L , Chen Ji-Kang , Kernan Chloe M , Gutmann David 
Published: November 2023

Abstract
While neuronal activity has previously been implicated in malignant glioma growth control, we recently demonstrated that neuron excitability can also regulate low-grade (optic) glioma initiation and progression. In this prior study, we showed that NF1 germline mutation-dependent neuronal excitability sustains optic glioma growth through HCN channel-mediated midkine activation of a T cell-microglia stromal circuit. Relevant to clinical translation, lamotrigine modulation of HCN channel function reduced neuronal hyperexcitability, midkine production and optic glioma (OPG) growth. To establish an obligate role for neuronal activity and midkine (Mdk) production in OPG growth, we leveraged a series of unique genetically engineered mouse models. First, we demonstrate that midkine is necessary for gliomagenesis, as Nf1-OPG; Mdk-/- mice do not develop tumors and have restored retinal pathology, as evidenced by increased retinal ganglion cell (RGC) numbers and retinal nerve fiber layer thickness. Second, we show that midkine production and neuronal hyperactivity are interdependent, such that only tumor-associated germline Nf1 mutations result in increased RGC excitability and midkine production, whereas those mutations that do not cause optic gliomas lack RGC hyperexcitability or elevated midkine expression. Third, lamotrigine treatment both during and after Nf1-OPG development attenuates midkine levels and tumor proliferation. Moreover, this anti-tumoral effect is durable for months after the cessation of treatment. Fourth, oral treatment of Nf1-OPG-bearing mice with clinically relevant doses of lamotrigine (2.5-7.5mg/kg/day) during OPG development blocks tumor formation. Together, these data establish midkine and neuronal hyperexcitability as key drivers of Nf1 optic glioma growth, relevant to planned clinical trials of this anti-seizure medication for children with NF1-OPG.
STEM-01. PLEXIN-B2 DRIVES CONFINED MIGRATION OF GLIOBLASTOMA STEM CELLS THROUGH MEMBRANE TENSION, ENDOCYTOSIS, AND MECHANO-ELECTRO REGULATION
Authors: Alves Chrystian Junqueira , Dixon Angela , Hannah Theodore , Wiener Robert , Nguyen Ha , Tipping Murray , Ladeira Júlia Silva , Dias Rodrigo Alves , Capriles Priscila Zabala , de Mendonça José Paulo Rodrigues Furtado , Slesinger Paul , Costa Kevin , Zou Hongyan , Friedel Roland 
Published: November 2023

Abstract
Glioblastoma is a malignant brain tumor of uncontrolled proliferation and infiltration. GBM stem cells (GSCs) are constantly challenged by confined spaces during their migration through the brain parenchyma. Understanding the factors that drive GSC confined migration (CM) is thus critical for effective drug development. Using microchannel devices, we showed that GSCs are adept at squeezing through narrow constrictions at faster speed than through non-constricted spaces. During CM, cytoskeletal components and plasma membrane self-organize to establish polarity and propel the cell through the constrictions. Among the mechanical plasticity observed for meeting the challenges of CM the cells remodel their shape and plasma membrane through increased endocytosis. Rapid endocytosis of inner leaflet anionic phospholipids-such as PI(4,5)P2 and phosphatidylserine at the front of the cell collectively contribute to drive positive-charged actin filaments and calcium to the rear end of cells, abruptly leading to localized changes in membrane potential and propelling the cell. Correspondingly, inhibiting endocytosis abrogates polarity and results in failure to CM. These effects were recapitulated by deletion of the cell surface receptor Plexin-B2. Plexin-B2-CRISPR knockout (KO) GSCs displayed reduced capability to squeeze through constrictions in microchannel devices. Mechanistically, Plexin-B2 KO in GSCs compromised membrane dynamics and reduced endocytosis as consequence of low cell stiffness and membrane tension. Computational simulations demonstrated that membrane tension couples with cell stiffness in feedback loops and support the model that Plexin-B2 controls membrane tension through actomyosin contractility. On a molecular level, the locked extracellular ring domain of Plexin-B2 prevents GSCs to migrate through constrictions and recapitulates the defects associated with Plexin-B2 KO phenotype, indicating that ring bending is required for membrane tension. Thus, our results describe critical mechano-electro events necessary to establish polarity and prompt GSCs migration under confinement and provide a mechanism by which a single mechanosensor exert regulation at the cytoskeletal and membrane levels.
STEM-16. PROMOTING THE CANCER STEM CELL SUBPOPULATION AND PHENOTYPE IN GLIOBLASTOMA VIA EXTRACELLULAR VESICLE CROSS-TALK
Authors: Inocencio Julio , Asad Mohammad , Aguilan Jennifer , Behnan Jinan , Sidoli Simone , Himes Benjamin 
Published: November 2023

Abstract

INTRODUCTION
Extracellular vesicles (EVs) released from cancer cells contain bioactive molecules that have been long implicated in tumorigenesis. In glioblastoma (GBM), there is mounting evidence that EVs play a role in critical processes including angiogenesis, immune suppression, and invasion. GBM secreted EVs have also been demonstrated to promote a cancer stem cell (CSC) phenotype by transporting stemness markers and proteins (I.e. Notch-1) involved in stem-cell activating pathways. Understanding the maintenance of CSCs, which contributes to tumor proliferation, treatment resistance, and re-expansion of the tumor bulk, can offer insight into new therapeutic drug targets that can disrupt this subpopulation.

METHODS
EVs were isolated from patient-derived primary GBM cell lines maintained as adherent cultures and free floating spheres (n = 3) using a staged ultracentrifugation technique. Normal astrocytes were used as the control group (n = 1). Protein expression profiles were then generated via high-throughput mass spectrometry for both EVs and whole cell lysate samples from the same cell line and compared against each other.

RESULTS
EGF-containing fibulin extracellular matrix protein 1 (EFEMP1) was shown to be upregulated in GBM derived EVs compared to control. Further analysis shows that EFEMP1 is enhanced in adherent cultures compared to free floating sphere cultures.

CONCLUSION
EFEMP1 is an extracellular matrix protein that has been identified as an oncogenic protein in GBM by activating Notch-1, Akt, and NF-Kb signaling pathways resulting in increased Temozolomide resistance, cellular proliferation, and invasion, all of which are hallmark characteristics of CSCs. EFEMP1 is also a downstream effector in the HIF-1 pathway, which has been strongly correlated in the maintenance of CSCs. Our results therefore demonstrate a possible EV mediated mechanism for the maintenance of the CSC population and phenotype in GBM.
STEM-21. DETERMINATION OF RACIAL DISPARITIES IN GLIOMA THROUGH RAP1B/NOTCH -INDUCED TUMORIGENESIS AND STEMNESS
Authors: Guo Shanchun , Guo Alyssa , Li Jason , Rama Vanajothi , Akpobiyeri Hannah , Hudson Breanna , Liu Mingli 
Published: November 2023

Abstract

BACKGROUND
The incidence of GBM and survival rates after diagnosis vary significantly by race, with Caucasian Americans (CAs) having higher incidence and lower survival rates than African Americans (AAs). Accumulating evidence suggests that the failure of current therapies is partly attributed to the presence of glioma stem cells (GSC), leading to tumor progression and recurrence. Our recent work demonstrates that Ras-associated protein 1 (Rap1), a Ras-like small GTP-binding protein superfamily member, has roles in glioma cell proliferation and invasion.

METHODS
1) The TCGA database was analyzed to investigate the predictive role of Rap1b in glioma patients. 2) The immunohistochemical staining for Rap1b1 was performed using the rabbit polyclonal anti-Rap1b in glioma tissue microarrays (TMA) from 76 glioma patients with 10 normal individuals. The staining intensity of cells in TMA was evaluated in three different bright fields (≥100 cells/field). The semi-quantitative HSCORE was calculated for Rap1b. 3) The mechanism of the oncogenic role of Rap1b in glioma was examined using in vitro cell culture.

RESULTS
1. TCGA data showed that Rap1b mRNA is highly expressed in GBM patients compared to normal controls, indicating that Rap1b is a potential oncotarget in GBM. Expression of Rap1b is associated with worse survival in glioma patients, especially in CAs, but not in AAs. 2. The TMA data showed that elevated Rap1b protein expression correlates with grades in glioma patients. 3. In vitro studies showed that GSCs exhibit high levels of Rap1b, silencing Rap1b decreases glioma cell growth and invasion through G1/S arrest and the induction of apoptosis, as well as reduces Notch1 signaling in glioma cells; while potentiates GBM cell response to TMZ.

CONCLUSION
This study provided new knowledge of Rap1b’s potential as a therapeutic drug target for GBM therapy and revealed biological diversity across races and unaddressed health disparities.
STEM-22. SINGLE-CELL LINEAGE TRACING IN PRIMARY GLIOBLASTOMA REVEALS DISTINCT PROGENITOR SUBTYPES DRIVING INTRATUMORAL HETEROGENEITY
Authors: Fazzari Elisa , Azizad Daria , Ge Weihong , Li Matthew , Tum Andrew , Tse Christopher , Patel Kunal , Muthukrishnan Sree Deepthi , Kornblum Harley , Nathanson David , Bhaduri Aparna 
Published: November 2023

Abstract
Glioblastoma (GBM) is the most common type of adult primary brain tumor with nearly a 100% rate of recurrence. One of the key clinical challenges is the vast degree of inter- and intra-tumoral variation in cell types and cell states, which change throughout the course of disease. Single-cell RNA-sequencing (scRNA-seq) studies in GBM samples have illuminated the complex landscape of cell type composition in primary and recurrent GBM, however these studies do not address how this diverse array of cell types developed or which cell populations are principally responsible for generating the heterogeneity and treatment resistance in the tumor. In this study, we implement a scRNA-seq compatible lineage tracing strategy, CellTagging, to track the behavior of individual tumor cells over time. Human GBM samples are dissociated immediately upon resection and infected with the CellTag DNA barcode library. The labeled cells are transplanted onto human cortical organoids, which facilitate the crucial normal-tumor cell interactions that enable GBM growth and invasion. After a period of proliferation, tumor cells are dissociated from the organoid and a fraction are harvested for scRNA-seq for transcriptomic and DNA barcode analysis. The remaining tumor cells are re-transplanted onto new organoids and harvested for scRNA-seq at later timepoints. Clonal relationships are determined by identifying cells with the same DNA barcode profile, and cell type characterizations are assigned via transcriptomic analysis. Transcriptomic profiling demonstrates the existence of multiple subtypes of tumor progenitors across timepoints. Strikingly, clonal analysis indicates that each progenitor subtype gives rise to numerous mature tumor cell types, suggesting multiple distinct lineages that contribute to tumor heterogeneity. Through differential expression analysis, we can predict which progenitors are most likely to drive which cell states. By introducing a treatment paradigm into our lineage tracing protocol, we identify tumor progenitor populations that contribute to treatment resistance.
CCRG-01. INFERENCE OF CELL CYCLE REGULATION BETWEEN GLIOBLASTOMA SUBPOPULATIONS IN VIVO TO DRIVE COMPUTATIONAL AND MATHEMATICAL MODELS OF THE CANCER COMPLEX SYSTEM
Authors: Harbour Nicholas , Curtin Lee , Velez Sebastian , Chappell Michael , Hubbard Matthew , Al-Dalahmah Osama , Canoll Peter , Owen Markus , Swanson Kristin 
Published: November 2023

Abstract
Glioblastoma (GBM) is the most aggressive and most common primary malignant brain tumor in adults, with a poor median survival time of 15 months. One of the key challenges in treating GBM is its highly heterogeneous nature, with multiple distinct subtypes that have been shown to occur on both inter- and intra-patient levels. Three main classifications, known as classical/proliferative, mesenchymal and proneural have become commonly demonstrated phenotypes. The cell cycle is a fundamental and highly conserved process that controls faithful division of cells; dysregulation of the cell cycle is known to be a key driver in many cancers. However, how the cell cycle is differently regulated between these subtypes has not been well classified in vivo. We investigate these three GBM subtypes using a recently published single nucleus RNAseq (snRNAseq) data set. We compare cell cycle regulation/dysregulation among these three subtypes using Tricycle, an R/Bioconductor package that utilises dimension reduction via principal component analysis and transfer learning to infer cell cycle position from any snRNAseq data set. We find that the classical GBM subtype has the highest proportion of actively dividing cells (cells in: S/G2/M phases), while the mesenchymal and proneural subtypes have a very low proportion of actively dividing cells. This supports the idea of a proliferation-migration dichotomy between GBM subtypes. We use this proportion of actively proliferating cells to calibrate a minimal spatiotemporal mathematical model for GBM tumor growth that accounts for the differences in cell cycle regulation between these three GBM subtypes.
CCRG-03. KAT5 REGULATES DEVELOPMENTAL TRANSITIONS AND CELLULAR HETEROGENEITY IN AN IN VIVO MODEL OF GLIOBLASTOMA
Authors: Mihalas Anca , Cucinotta Christine , Arora Sonali , Kim Dayoung , Tsukiyama Toshio , Plaisier Christopher , Patel Anoop , Paddison Patrick 
Published: November 2023

Abstract
In solid tumors, G0-like states are likely critical for maintaining developmental hierarchies and cellular heterogeneity and promoting tumor growth/recurrence, yet little is known about tumor G0 states or regulation of their ingress/egress. To discover G0-like states and their regulators for glioblastoma (GBM), we previously performed a genome-wide CRISPR-Cas9 screen in patient-derived GBM stem-like cells (GSCs) for genes that trap cells in G0 when inhibited. We identify the protein acetyltransferase KAT5 as a key regulator of GBM G0 ingress/egress. Here, we show in an in vivo GSC-derived orthotopic xenograft model that KAT5 regulates transcriptional, epigenetic, and proliferative heterogeneity impacting transitions into G0-like states. We show that KAT5 activity suppresses the emergence of non-dividing subpopulations with oligodendrocyte progenitor and radial glial cell characteristics. With regard to chromatin regulation, we show that loss of KAT5 activity alters sites of mixed epigenetic valency (which have both activating and repressive marks in bulk tumor populations) to promote emergence of OPC/RG G0-like populations in tumors. Our data reveal KAT5-associated transcriptional and epigenetic changes in tumors, which indicate that KAT5 activity biases cell state distribution away from OPC and RG-like subpopulations. In addition, loss of KAT5 resulted in a less invasive phenotype and prolonged survival of mice harboring orthotopic xenografts.