bluuebunny/crossref_metadata_2025_split huggingface dataset:
STEM-02. SYNGN: A NOVEL EPIGENETIC PLATFORM FOR PATIENT-SPECIFIC DRUG-MATCHING IN GLIOBLASTOMA
Authors: Vinel Claire , Boot James , Zabet Radu , Brandner Sebastian , Marino Silvia 
Published: November 2023

Abstract
The alteration of the glioblastoma genome by epigenetic mechanisms that share functions with normal developmental processes, such as self-renewal and fate specification of NSC, is a key piece of evidence that links brain cancer pathogenesis with dysregulated stem cell functions. A patient-specific comparison of glioblastoma cells with NSC, a putative cell of origin of at least a proportion of these tumours, is not feasible as patient-matched endogenous NSC are not surgically accessible and all epigenetic studies in glioblastoma have so far compared epigenetic changes of different tumours with each other or to comparators obtained from foetal brains or an unrelated donor. We reasoned that availability of syngeneic GSC and NSC pairs would allow to identify crucial epigenetic differences on a patient-specific basis and would provide essential therapeutic contrast to define disease-and patient-intrinsic biomarkers of drug response that are less confounded by germline variation. We have derived GSC from IDH-wildtype glioblastoma and harnessed state-of-the-art stem cell technologies to generate patient-matched fibroblast-derived EPSC, which were induced to NSC (iNSC). We demonstrate that integrated analysis of the transcriptome and DNA methylome of GSC/iNSC pairs identifies druggable target genes (PTGER4, ALDH3B1, NTRK2) in a proportion of patients and we validate this patient-specific prediction of drug response at pre-clinical level in 3D synGLICO and in in vivo models. Integration of small RNA regulation to the pipeline allows refined in silico prediction of drug responses on a patient-specific basis. Most recently we have added assessment of chromatin remodelling (H3K4me3, H3K27ac, H3K3me3, H3K27me3 and ATACSeq) to the pipeline and shown that redistribution of selected histone marks as well as shifts in chromatin states across the genome identifies known and novel druggable regulatory mechanisms in GSC, which are specific of the neoplastic context. In conclusion, SYNGN is an epigenetic platform which can identify patient-specific druggable targets in glioblastoma.
STEM-05. HYPOXIA AND ACIDOSIS PROMOTE YAP/TAZ ACTIVATION, POTENTIALLY SUPPORTING GLIOMA STEM CELL MAINTENANCE IN THE PERI-NECROTIC ZONES
Authors: Shih Ling-Kai , Li Jiabo , Carneiro-Lobo Tatiana , Olson Cheryl , Brat Daniel 
Published: November 2023

Abstract
Glioblastoma (GBM) is a highly malignant brain tumor characterized by rapid growth and poor clinical outcomes. The development of necrosis is associated with massive tumor microenvironment (TME) reshaping and rapid progression characterized by accumulation of tumor-associated macrophages (TAMs) and glioma stem cells (GSCs) in peri-necrotic zones. Using Ivy-GAP and single-cell RNA seq data, we found that many canonical stem-cell associated transcription factors (SOX2, OLIG2, FOXM1) were not upregulated in the hypoxic peri-necrotic zone, yet Hippo transcriptional activation was consistently noted under these conditions. We hypothesized that Hippo activation promotes GSC stemness and may be due to direct effects of hypoxic; the acidic conditions associated with necrosis; or by cytokines secreted by adjacent TAMs. Using patient-derived GBM neurosphere cultures, we exposed glioma cells to 1% hypoxia and found that nuclear expression of YAP1 and TAZ, as well as Hippo pathway readout CYR61, were upregulated compared to normoxia (21%) at 48 hrs, indicating Hippo activation. Exposing cells to an acidic environment (pH 6.3) also caused Hippo transcriptional activation independent of hypoxia. Using single-cell RNA-seq data, we uncovered potential hypoxia-regulated upstream genes that could be responsible for nuclear YAP/TAZ transportation under hypoxia, including Zyxin, WBP2, and PP2A. We also found that culturing GBM cells with media conditioned by human primary macrophages activated Hippo transcription. Using human cytokine arrays, we identified cytokines that showed increased levels in TAM-conditioned media, including EGF, CXCL8, TGF-β, and CXCL5. Treating GBM cells with either hypoxia or a pharmacological activator of YAP/TAZ led to the upregulation of proteins in the inhibitor of differentiation (ID) family (ID1, ID2), which could represent a downstream mechanism related to stem-like behavior following Hippo activation. Our data support the conclusion that hypoxia and TAM cytokines directly stimulate YAP/TAZ activation to potentially promote GSC maintenance in the GBM peri-necrotic niche.
STEM-06. OSMR INTERACTOME MAPPING REVEALS THE SIGNIFICANCE OF A CHLORIDE CHANNEL IN CYTOKINE REGULATION AND BRAIN TUMOUR STEM CELL SELF-RENEWAL
Authors: Randhawa Kamaldeep , Raco Laura , Snider Jamie , Stagljar Igor , Jahani-Asl Arezu 
Published: November 2023

Abstract
Oncostatin M Receptor (OSMR) is a key regulator of brain tumour stem cell (BTSC) self-renewal and glioblastoma (GB) tumourigenesis. This receptor is found in a complex with Epidermal Growth Factor Receptor variant III (EGFRvIII) and orchestrates a positive feedback loop with STAT3. OSMR also regulates oxidative phosphorylation and participates in promoting the transition of cells towards mesenchymal-like glioma states. How OSMR drives GB tumorigenesis via multiple mechanisms remains largely unclear. Here, we map OSMR interactome in different GB subtypes using the Mammalian Membrane Two Hybrid High Throughput Screen (MaMTH-HTS). Analysis of these data followed by functional validation has uncovered distinct OSMR interactome in a context dependent manner. Follow up investigations, however, have led to the discovery of the Chloride Intracellular Channel 1 (CLIC1), essential in the regulation of OSMR cytokine signaling and GB progression independently of the genetic profile of the GB tumour. CLIC1 forms a complex with OSMR to promote BTSC self-renewal and knockout of CLIC1 or pharmacological inhibitors to CLIC1 impairs OSM mediated STAT3 phosphorylation. Our work suggests that CLIC1 and OSMR form a complex in BTSCs and functionally interact to activate STAT3.
STEM-10. SOX2 POSITIVE, PRESUMED TUMOR INVASION MEASURED WELL BEYOND CONTRAST ENHANCEMENT AND FLAIR HYPERINTENSITY IN BOTH TREATED AND UNTREATED GLIOBLASTOMA PATIENTS ASSESSED AT AUTOPSY
Authors: Stebbins Margaret , Bobholz Samuel , Duenweg Savannah , Lowman Allison , Flatley Michael , Nath Biprojit , Kyereme Fitzgerald , Winiarz Aleksandra , Connelly Jennifer , Coss Dylan , Krucoff Max , Banerjee Anjishnu , LaViolette Peter 
Published: November 2023

Abstract
In the treatment of glioblastoma (GBM), MRI is used to determine location and extent of cancer. It is poorly understood how far tumor invasion may exist outside of contrast enhancement (CE) and FLAIR hyperintensity (FL). This study identifies presumed non-enhancing tumor invasion using SOX2 staining on tissue collected at autopsy, which may highlight invading glioma cells. Three patients with primary GBM were included for this study. Patient 1 (P1) with an overall survival (OS) of 148 days received no treatment following sub-total resection. Patient 2 (P2) (OS = 1601) and patient 3 (P3) (OS = 629 days) underwent the clinical standard of care treatment including chemo-radiation and bevacizumab at recurrence. At autopsy, brains were sliced axially to match patients’ last MRI scan. Samples were obtained including regions suspicious of tumor and regions appearing normal. SOX2 positive cells were identified visually on digitized autopsy histology. Samples were visually matched to the patient’s last T1C and FLAIR MRI acquisition prior to death. Approximate distance from CE and FL from SOX2 positive cells was measured digitally, limited to the same MRI slice (2D assessment). For P1 who received no treatment, SOX2 positive cells were identified 3.9cm from CE and 4.1cm from FL within the same hemisphere as the primary tumor, and 2.1cm and 2.3cm within the opposite hemisphere, respectively. For P2 and (P3), SOX2 positive cells were identified approximately 4.4cm (5.2 cm) from CE and 4.0cm (2.0cm) from FL within the same hemisphere as primary tumor, and 4.7cm (4.4cm) from CE and 4.1 cm (4.7cm) from FL within the opposite hemisphere. This study uses SOX2 to identify presumed GBM cells well beyond clinically identified regions of tumor, on T1C and FLAIR imaging. Additional research is necessary to determine SOX2 sensitivity and specificity for identifying GBM cells outside regions with readily identifiable GBM characteristics.
STEM-12. TARGETING GLIOBLASTOMA WITH A BRAIN PENETRANT DRUG THAT IMPAIRS BRAIN TUMOUR STEM CELLS
Authors: Jahani-Asl Arezu 
Published: November 2023

Abstract
Brain tumour stem cells (BTSCs) are a population of self-renewing malignant stem cells that play an important role in glioblastoma tumour hierarchy and contribute to tumour growth, therapeutic resistance, and tumour relapse. Thus, targeting of BTSCs within the bulk of tumours represents a crucial therapeutic strategy. Here, we report a potent brain penetrant drug (AJ5939) that impairs BTSCs and impedes glioblastoma progression. We show that AJ5939 inhibits the self-renewal and growth of BTSCs harbouring a diverse range of oncogenic mutations without affecting non-oncogenic neural stem cells. Global gene expression profiling revealed significant alterations in BTSC transcriptome and attenuation of the expression of a large panel of genes involved in cell cycle progression, stemness, and DNA repair mechanisms. Mechanistically, we show that AJ5939 impairs Notch signalling pathway via directly targeting this pathway and altering the stemness signature. In combination with ionizing radiation (IR), however, AJ5939 suppresses the DNA repair mechanisms and facilitate the response of the BTSC to ionizing radiation induced cell death. Finally, we present data that AJ5939 treatment of brain tumours in preclinical models significantly prolongs lifespan.
STEM-15. STAT5-OLIG2 TRANSCRIPTIONAL COMPLEX MEDIATES GLIOMA STEM CELL SELF RENEWAL AND INVASION
Authors: Miller Aunay , Cascio Costanza Lo , Blomquist Mylan , McNamara James , Orndorff Keely , Dufault Matthew , Sereduk Christopher , Loftus Joseph , Mehta Shwetal , Tran Nhan 
Published: November 2023

Abstract
Glioblastoma (GBM) is the most common and lethal primary brain tumor in adults, despite current treatment options. One of the major contributing factors to this dismal outcome is a subset of cells called glioma stem cells (GSCs) that are highly tumorigenic, invasive, and resistant to conventional treatments. Thus, studies that focus on the properties of GSC biology are needed to develop novel therapies to improve overall survival. Here we report a novel role of STAT5 in GSC stemness and survival. In GBM tumors, STAT5 has been shown to be active in the infiltrative, residual population of cells remaining post-surgery. Knockdown of STAT5 results in the decrease in GSC stemness and therapeutic resistance. Interestingly, we find that expression of OLIG2, a key cell fate factor important for the tumorigenic potential of GSCs, affects STAT5 activation with a positive correlation between OLIG2 and STAT5 mRNA expression in GBM tumors. Furthermore, we find that in GSCs expressing EGFRvIII, STAT5 interacts with OLIG2 and pharmacological inhibition of STAT5 activation or knockdown of STAT5 expression results in decrease of OLIG2-mediated GSC invasion. Together, these data suggest a novel transcriptional complex, STAT5-OLIG2, in the potential role for GSC survival, maintenance, and invasion.
STEM-20. REGULATION OF GLIOMA STEM CELL MAINTENANCE AND THERAPEUTIC RESISTANCE BY EGFR MISSENSE MUTATIONS
Authors: Weaver Sidney , Miller Aunay , Blomquist Mylan , McNamara James , Orndorff Keely , Kloss Jean , Sereduk Christopher , Loftus Joseph , Mehta Shwetal , Tran Nhan 
Published: November 2023

Abstract
Glioblastoma (GBM) tumors contain a subpopulation of glioma stem cells (GSC) which can escape therapeutic effects through self-renewal and invasion. Epidermal growth factor receptor (EGFR) mutations are the most common alteration in GBM. EGFRvIII (deletion of exons 2-7) is observed in GBM (20-25%) resulting in a constitutively activated EGFR receptor. In addition, extracellular domain missense point mutations, (e.g. G598V, A289V, R108K) are observed in GBM (14.4%). These missense mutations in the EGFR extracellular domain also induces a highly active receptor by enhancing ligand binding. Earlier reports have shown that these EGFR missense point mutations have exhibited therapeutic resistance; however, the molecular mechanism of these missense point mutations in GBM remains unknown. Previous studies in our lab showed that EGFRvIII promotes GSC maintenance and therapeutic resistance via oligodendrocyte transcription factor 2 (OLIG2) signaling. OLIG2 is universally expressed in glioma and essential for reprogramming GBM cells into stem-like tumor cells. Increased OLIG2 expression promotes invasion, growth, proliferation, and survival. Here we report an increase in OLIG2 protein expression in GSCs harboring EGFR-G598V or EGFR-A289V mutations, suggesting these mutations may support stemness properties in GBM tumors. GSC expressing these point mutations display increased self-renewal, growth, and survival. In addition, EGFR-G598V and EGFR-A289V trigger distinct downstream signaling pathways in GSCs to regulate OLIG2 function. Hence, we hypothesize that GBM tumors harboring EGFR missense mutations (G598V, A289V) influence stem cell properties via multiple pathways to evade therapeutic effects and inhibiting these different signaling pathways will decrease therapeutic resistance in GBM. Understanding the mechanism of these EGFR mutations may lead to improved therapeutic strategies for GBM patients.
CCRG-04. AUTOMATED REAL TIME TRACKING OF GLIOBLASTOMA CELL CYCLE TRANSITIONS IN ASSEMBLOIDS LINKS G2 CELLS TO INFILTRATION
Authors: Akhunbay-Fudge Christopher Yusuf , Critchley Kevin , Mathew Ryan , Wurdak Heiko 
Published: November 2023

Abstract
Glioblastoma (GB) is the most aggressive primary brain tumour in adults associated with survival rates below 5% despite treatment. Tumour repopulating residual cells in the surgical cavity resist treatment due to their molecular heterogeneity. Single-cell transcriptomic studies have linked GB heterogeneity to the cell cycle; however, it remains unclear to what extent cell cycle states affect the infiltrative capacity of GB. The “go or grow” paradigm predicts that migration and proliferation are separate spatiotemporal events. We used a brain tumour-cerebral organoid (assembloid) approach to test the migratory potential of GB cell cycle phases during assembloid infiltration. Human induced pluripotent cells were differentiated into cerebral organoids that self-assemble with spheroids of patient-derived GB cells, expressing a fluorescent cell cycle reporter (FUCCI). Utilising live-cell confocal imaging, the process of GB assembloid infiltration was captured. Resultant videos were analysed with automated image analysis capable of tracking cell cycle transitions and cellular migration in confocal microscopy planes, enabling the longitudinal quantification of GB migration and invasion. Our analysis revealed a subset of highly infiltrative GB cells, containing a significant number of cycling G2 phase cells that demonstrated a ~1.4-fold increase in directional infiltrative capacity compared to their non cycling G1 phase counterparts. To isolate and characterize the G2 migratory GB cell state, we developed a phenotypic separation assay using microenvironmental cues. Specifically, we found that these cues markedly affect GB migration routes enabling the isolation of the highly migratory GB cells for further investigation. Our results question the “go or grow” hypothesis at the level of GB cellular subpopulations. We hypothesise that the observed G2 migratory capacity of GB cells could be critical to tumour recurrence following surgery. Further research is underway to define the underlying mechanisms of G2 GB cell migration.
CCRG-05. A UNIFYING AND SELF-REINFORCING MECHANISM OF TUMOR IMMORTALITY IN TERT PROMOTER MUTANT CANCERS
Authors: Stevers Nicholas , Barger Carter , Yuan Jimmy , Kim Somang , Hong Chibo , Lenzo Olivia , McKinney Andrew , Wu Samuel , Lee Yu-Jin , Collins Sara , Batsios Georgios , Kwok Darwin , Suwala Abigail , Appin Christina , Viswanath Pavithra , Kasahara Noriyuki , Gordan John , Molinaro Annette , Song Jun , Costello Joseph 
Published: November 2023

Abstract
Telomerase Reverse Transcriptase promoter mutations enable tumor cell immortality in millions of cancer patients annually. While prior therapies targeting telomerase lacked tumor selectivity and were poorly tolerated, TERT promoter mutations and their regulation present a unique opportunity for tumor specific reversal of cellular immortality. The two hotspot mutations, G228A and G250A, generate identical de novo E26 transformation specific (ETS) transcription factor binding sites. However, the 28 ETS factors share a similar binding site preference, raising the question of whether all ETS factors can reactivate TERT. In glioblastoma and a few other cancers, we have shown the de novo ETS site along with a nearby native ETS site (ETS-195/200) recruit one ETS factor, the GA-binding protein (GABP) tetramer, to reactivate TERT. This GABP-mediated mechanism may be restricted to specific cancer types and the two hotspot mutations or could be widely relevant to any cancer with a de novo ETS TERT promoter mutation. We have found that the GABP tetramer activates 6 distinct mutant TERT promoters across 16 different cancer types. However, TERT expression is maintained in most tetramer depleted tumor cells as the tetramer is serially replaced by GABP dimers and weakly by a paralogous tetramer complex that increase following disengagement of GABP tetramer-mediated negative feedback loops. Elimination of both the tetramer and dimer reinstates epigenetic repression of TERT, shortens telomeres, and prevents cancer cell division. However, some knockout cancer cells avoid this fate through weak activation of TERT by the paralogous GABP tetramer complex. The compensatory maintenance of TERT expression can be overcome with a dominant negative GABPB1, leading to TERT silencing, evidenced by gene expression and non-invasive metabolic imaging correlates, and telomere shortening in TERT promoter mutant glioblastoma. We are currently investigating the delivery of this dominant negative to tumor cells via clinically approved retroviral replicating vectors.
CCRG-07. GOLD NANOPARTICLES DEMONSTRATE FAVORABLE EFFECTS ON THE BEHAVIOR OF MESENCHYMAL STEM CELLS, THEREBY AUGMENTING THEIR OVERALL BIOLOGICAL PERFORMANCE
Authors: Shen Chiung-Chyi , Lin Ruei-Hong , Yang Yi-Chin , Hung Huey-Shan 
Published: November 2023

Abstract
Gold nanoparticles (AuNPs) have been extensively studied for their interaction with cells, particularly mesenchymal stem cells (MSCs), and their potential to influence various cellular behaviors such as proliferation and differentiation. In this research, AuNP solutions at concentrations ranging from 1.25 to 10 ppm were prepared to investigate their biocompatibility. The presence of AuNPs was confirmed using ultraviolet-visible spectroscopy, while Dynamic Light Scattering assay characterized their size and scanning electron microscopy revealed their shape. MSCs were treated with different concentrations of AuNPs to assess biocompatibility. The results indicated that 1.25 and 2.5 ppm concentrations of AuNPs significantly enhanced MSC proliferation, reduced reactive oxygen species generation, and attenuated platelet/monocyte activation. Furthermore, the presence of filopodia and lamellipodia suggested improved adhesion ability of MSCs when incubated with 1.25 and 2.5 ppm AuNPs. The expression of matrix metalloproteinase (MMP-2/9) was also upregulated under these concentrations, indicating enhanced cell migration ability. Lower levels of apoptosis were observed in MSCs treated with 1.25 and 2.5 ppm AuNPs compared to higher concentrations, as assessed by Annexin-V/PI double staining and Fluorescence Activated Cell Sorting (FACS). Western blotting analysis showed increased expression of anti-apoptotic proteins Cyclin-D1 and Bcl-2. Additionally, real-time PCR analysis demonstrated reduced expression of inflammatory cytokines (TNF-α, IL-1β, IFN-γ, IL-6, and IL-8) in MSCs treated with 1.25 and 2.5 ppm AuNPs. Animal model tests revealed that these concentrations of AuNPs exhibited better biocompatibility, including anti-inflammatory effects and endothelialization. Overall, 1.25 and 2.5 ppm AuNP solutions were shown to enhance the biological functions of MSCs, suggesting their potential as biocompatible nanomedicine for regenerative research.
CSIG-01. DEFINING THE INVOLVEMENT OF THE PERIVASCULAR NICHE IN BRAIN TUMOR METASTASES
Authors: Fong Vernon , Abeysundara Namal , Livingston Bryn , Richman Cory , Erickson Anders , Taylor Michael 
Published: November 2023

Abstract
Medulloblastomas (MB) are the most prevalent malignant pediatric brain tumors, originating in either the cerebellum or the dorsal brainstem. They are classified into four distinct subgroups (WNT, SHH, Group 3, and Group 4), characterized by unique gene expression profiles, metastatic patterns, and recurrence rates. Metastatic progression of MB is frequently associated with poor prognosis, affecting approximately 30% of patients at diagnosis. Despite considerable research on primary tumors, there are currently no approved specific treatments for MB leptomeningeal metastases. Thus, gaining further insights into metastatic MB and developing targeted therapies are imperative. The leptomeningeal niche, where metastatic MB tumor cells reside, comprises a complex network of blood vessels supported by perivascular cells, including pericytes, smooth muscle cells, and fibroblasts. However, the specific adhesion molecules and signaling pathways within the leptomeningeal niche that contribute to tumor cell colonization remain elusive. In this study, we hypothesize that the perivascular niche plays a critical role in the colonization and survival of metastatic cells within the leptomeninges. To investigate this, we employed an innovative sLP-mCherry niche labeling system in conjunction with single-cell RNA sequencing to spatially identify and examine the perivascular cells neighboring metastatic MB tumor cells. Through our analysis, we identified upregulated genes associated with cholesterol export in tumor-associated perivascular cells, suggesting their potential involvement in supporting metastatic cell colonization. To further explore this mechanism, we utilized CRISPR and lentiviral overexpression constructs to modulate cholesterol uptake in MB cell lines, observing subsequent changes in metastatic burden. In summary, our study elucidates the importance of the perivascular niche in metastatic medulloblastomas and provides novel insights into the molecular mechanisms that drive tumor cell colonization within the leptomeninges. These investigations into the lipid transport mechanism in the vascular microenvironment opens doors for the development of innovative treatments targeting MB metastases.