bluuebunny/crossref_metadata_2025_split huggingface dataset:
CSIG-06. CROSSTALK BETWEEN ONCOGENIC SIGNALING PATHWAYS AS DRIVERS OF THERAPY RESISTANCE AGAINST SMALL MOLECULE INHIBITORS IN GLIOBLASTOMA
Authors: Hoosemans Linde , van Heumen Mike , Verduin Maikel , Hoeben Ann , Vooijs Marc 
Published: November 2023

Abstract
Patients with glioblastoma multiforme (GBM) have a median survival of 15 months. Despite an intensive treatment schedule with resection, radio- and chemotherapy, recurrence is inevitable. An important challenge to overcome GBM treatment resistance involves intratumoral heterogeneity, characterized by molecularly, phenotypically, and clinically distinctive GBM subtypes. Different small molecule inhibitors have been designed to inhibit signaling proteins in oncogenic driver pathways, including the EGFR, PDGFR, MET, CDK4, and PI3K/Akt pathway, in GBM. However, these small molecule inhibitors have been unsuccessful in improving patient outcome. Here, we investigate if crosstalk and redundancy in signaling pathways is responsible for single-agent resistance using patient-derived glioblastoma 2D stem cell cultures (pdGBM). Eight brain-penetrable and clinically approved small molecule inhibitors (SMI) were used to target key GBM driver genes. We measured cell viability in triplicate with a CellTiter-Glo assay. The half-maximal inhibitory concentration (IC50) for each inhibitor was defined for six molecularly distinct pdGBM 2D cell cultures. Although inhibition of downstream effector proteins reduced cell viability more effectively (IC50 70nM-1µM), compared to inhibiting upstream membrane-bound tyrosine kinase receptors (IC50 1-15µM), remaining cell proliferation was seen in all pdGBM using the different SMIs as single agent. To identify resistance mechanisms, we investigated changes in phosphokinase activity after SMI monotherapy in the different pdGBM 2D cell cultures. Based upon these results, we could identify combinations of SMIs targeting compensatory pathways that drive treatment resistance. In conclusion, this study presents a mechanistically driven selection of tumor tailored combination treatment to overcome resistance to SMI monotherapy in pdGBM. The efficacy of these novel SMI combinations will be challenged next, moving from pdGBM 2D stem cell cultures towards pdGBM organoids.
CSIG-07. HYPERCELLULAR NODULES IN OLIGODENDROGLIOMA REPRESENT POCKETS OF PROLIFERATIVE STEM-LIKE TUMOR CELLS
Authors: Liu Mengyi , Abramson Karen , Hocke Emily , Hilz Stephanie , Costello Joseph , McLendon Roger , Ashley David , Gregory Simon , Lopez Giselle 
Published: November 2023

Abstract

INTRODUCTION
Oligodendrogliomas are a progressive, infiltrative glioma. By histology, a subset of oligodendrogliomas demonstrate hypercellular nodules (HCN), which often have increased anaplasia compared to surrounding tumor. However, the signals driving anaplasia are unknown.

METHODS
We first performed a GeoMX 89-protein Digital Spatial Profiling (DSP, Nanostring) panel on a cohort of ten oligodendrogliomas with HCN., followed by spatial whole RNA transcriptome analysis (10x Genomics Visium) on six oligodendrogliomas. For the latter, following unsupervised clustering, we performed Gene Ontology (GO) enrichment analysis and Ingenuity Pathway Analysis (IPA, Qiagen) on the differentially expressed genes between HCN and adjacent tumor. We performed paired single nucleus RNA sequencing for deconvolution of the spatial transcriptomic data.

RESULTS AND CONCLUSIONS
By protein DSP, we identified a marker of stemness (OLIG2) and a proliferation marker (Ki-67) as present at increased levels (p&lt; 0.05) within HCN. We subsequently performed spatial whole transcriptome analysis. On unsupervised clustering of differentially expressed genes, the HCN spots cluster away from the remaining tumor spots, supporting a distinct niche. GO and IPA both identified increased activity in several central nervous system developmental pathways, providing further evidence for the “precursor-like” state of cells in HCN. We then annotated paired single nucleus RNA sequencing results to align tumor cells with astrocytic-like, oligodendroglial-like, and stem-like cell states. Using this to deconvolute the spatial transcriptomic data, we found that the vast majority of HCN are enriched for either stem-like or OC-like/stem-like tumor cells. Taken together, the findings support HCN as niches for the most precursor-like, proliferative oligodendroglial cells.
CSIG-14. THE IMPACT OF CORTICOTROPHIN RELEASING HORMONE STRESS NEURO-HORMONES ON THE VIABILITY AND PROLIFERATION OF BRAIN TUMOURS
Authors: Monteiro Ana Rita , Swinny Jerome 
Published: November 2023

Abstract
The majority of brain tumour sub-types are of glial origin. These include high-grade gliomas (HGGs), which lack effective targeted therapies and are thus invariably lethal. We have shown that stress leads to proliferation of brain glia. Such stress-induced glial cell division could provide opportunities for detrimental genetic mutations which increase the risk of oncogenesis. Identifying stress-induced glial plasticity could uncover molecular targets that directly influence glioma viability. Corticotropin-releasing hormone (CRH) stress neurohormones, including urocortin I-III (UCN I-III) are key mediators of stress signalling in the brain including neuroplastic processes. The aims of this project were to compare the expression CRH peptides and receptors in different types of brain tumours and their impact on cells viability and proliferation. Five different brain tumour cell lines were used (two biopsy-derived-in-house-established HGGs – UP007 and SEBTA023 – and three commercially available Medulloblastomas, MBs – UW402, CHLA-01-MED and CHLA-01R-MED). The gene expression profiles of the CRH family were accessed by qRT-PCR (n = 5) and the protein expression by Immunocytochemistry and flow cytometry (FC, n = 3). The effects of targeted drug modulation were assessed through viability (MTS, n = 3) and proliferation assays (Cyquant NF cell proliferation, n = 3). Statistical significance of qRT-PCRs and FC were calculated through a Kruskal-Wallis test, and for viability and proliferation assays through a two-way ANOVA approach. Values of P &lt; 0.05 were accepted as significant. The qRT-PCRs revealed a higher expression of stress neuro-hormones mRNA in MBs compared to HGGs. Immunocytochemistry confirmed the protein expression of CRH and downstream receptors in all cell lines, while FC revealed a higher expression of CRH-Rs in HGGs than MBs. The pharmacological modulation of CRH-Rs induced contrasting effects on cellular viability and proliferation, suggesting patient-specific CRH-CRH-R pathway. This raises the prospect of repurposing available CRH-R ligands for targeted treatment of susceptible tumour types.
CSIG-16. PTEN LOSS IN GLIOMA CELL LINES FACILITATES IMMUNE EVASION BY UPREGULATING EXTRACELLULAR VESICLE BIOGENESIS AND PD-L1 CARGO
Authors: Sanchez Julio , Pierpont Timothy , Argueta-Zamora Dariana , Wilson Kristin , August Avery , Cerione Richard 
Published: November 2023

Abstract
Phosphatase and tensin homologue (PTEN) is deleted or mutated in over 50% of all glioblastoma (GBM) cases. Recently, PTEN loss has been implicated as a prognostic biomarker for patients likely to be non-responders treated with immune checkpoint inhibitor (ICI) therapy. Indeed, a growing body of evidence has highlighted the loss of PTEN with immuno-modulatory functions including the upregulation of the programmed death ligand-1 (PD-L1) and the development of an immunosuppressive tumor immune microenvironment (TIME), likely the result of an altered secretome. This raised the question of whether the loss of PTEN impacts the biogenesis and function of extracellular vesicles (EVs), given their functional contributions to immunosuppression and tumor growth. Here we show that glioma cell lines with no or reduced PTEN expression produce elevated numbers of EVs, as measured through nanoparticle tracking analysis. Pharmacological inhibition of PI3K reversed this observation, indicating that this phenomenon occurs in a PI3K-dependent manner. Moreover, we show through flow cytometry and immunoblot analysis that the ability for the inflammatory cytokine interferon-γ (IFN-γ) to upregulate PD-L1 at the cell surface and as EV-associated cargo is markedly increased in cells lacking PTEN. Lastly, we show that in response to IFN-γ, EVs derived from glioma cells lacking PTEN exhibit an enhanced ability to inhibit TCR signaling in a Jurkat reporter system. Taken together, these findings shed new light on how the loss of a major tumor suppressor, PTEN, can alter EV biogenesis and function and contribute to an immunosuppressive extracellular milieu. Future studies will be directed toward exploring whether loss of PTEN function alters additional EV-associated immuno-modulatory proteins relevant to other immune cell populations, toward gaining a further understanding of how EVs shape the “cold” TIME of GBM and the potential therapeutic benefit of combining PI3K inhibitors with ICIs.
CSIG-19. CANCER STEM CELL MEDIATED F11 DRIVES HYPER-THROMBOTIC ACTIVITY IN GLIOBLASTOMA
Authors: Sloan Anthony , Sloan Andrew , Khorana Alok , Horbinski Craig , Cameron Scott , Gupta Anirban Sen , Lathia Justin 
Published: November 2023

Abstract
Cancer-related thrombosis is the second leading cause of death for cancer patients and glioblastoma (GBM), the most common primary malignant brain tumor, is associated with approximately a 30% risk of venous thromboembolism, deep vein thrombosis, or pulmonary embolisms. While this remains a major clinical issue, the interaction between platelets and cancer cells has been underexplored in solid tumor models that do not metastasize, including GBM. GBM is a tumor which contains a high degree of cellular heterogeneity and has populations of therapeutically resistant cancer stem cells (CSCs) that drive tumor growth. Histologically CSCs are found in perivascular and pseudsopalisading regions of GBM, which are also areas of platelet localization. High platelet counts have been associated with poor clinical outcome in many cancers and while platelets are known to promote progression of other tumors. Our previous work demonstrated that CSCs co-opt and activate platelets to promote CSC growth by intrinsically producing thrombin via a cell intrinsic functional coagulation cascade. These findings provided further evidence that CSCs readily execute a highly liver-specific gene expression program that is mechanistically linked to GBM growth. We now demonstrate thrombin and platelet expression in GBM patient specimen creates a hyper-thrombotic GBM tumor-microenvironment. Further, genetic targeting of the CSC intrinsic coagulation cascade, via knockdown of coagulation factor 11 (F11), reduces CSC growth and tumor formation while also decreasing the ability for CSCs to activate platelets, subsequently decreasing the hyper-thrombotic state seen in GBM. Our observations suggest that CSCs execute a cell intrinsic coagulation mechanism to contribute to the hyper-thrombotic tumor-microenvironment seen in GBM and may shed light onto mechanisms of cancer associated thrombosis in not only GBM, but also other malignancies.
CSIG-20. SYSTEMATIC REVIEW OF MOLECULAR TARGETED THERAPIES FOR ADULT-TYPE DIFFUSE GLIOMA: AN ANALYSIS OF CLINICAL AND LABORATORY STUDIES
Authors: Muzyka Logan , Goff Nicolas , Choudhary Nikita , Koltz Michael 
Published: November 2023

Abstract
Gliomas are becoming a frequent topic of investigation for molecular-targeted therapies. However, the current state of research in this area, particularly following the 2021 WHO guideline change, remains undefined. This systematic review sought to characterize the current state of molecular target therapy research for adult-type diffuse glioma to inform scientific progress. A systematic review was conducted in accordance with PRISMA guidelines. Studies meeting inclusion criteria were queried for study design, tumor type, molecular target, molecular pathway, and details pertaining to the molecular targeted therapy– namely the modality, dose, duration of treatment. 350 studies met inclusion criteria: 52 of these were clinical studies, 190 were laboratory studies investigating existing molecular therapies, and 108 were laboratory studies investigating new molecular targets. 119 ongoing clinical trials are also underway, per a detailed query of clinicaltrials.gov. GBM was the predominant tumor studied, with few studies mentioning IDH-mutant astrocytoma or oligodendroglioma. The most common molecular targets in published clinical studies and clinical trials were protein kinase pathways, followed by microenvironmental targets, then immunotherapy and cell cycle/apoptosis pathways. The most common molecular targets in laboratory studies were protein kinase pathways, followed by cell cycle/apoptosis, microenvironmental targets, then immunotherapy pathways, with the wnt/β-catenin pathway arising as a novel target. This systematic review examined the current evidence on molecular targeted therapy for adult-type diffuse glioma and discusses its implications for clinical practice and future research. Published research encompasses clinical studies, laboratory testing of existing therapies, and identification of novel targets, with GBM as the focal point. Ongoing clinical trials are numerous in this area of research as well and follow a similar pattern in tumor type and targeted pathways as published clinical studies. The most common molecular targets were protein kinase pathways, with some variation in the prevalence of other pathways depending on study type.
CSIG-23. PRIMARY CILIA DISRUPTION ALTERS THE TRANSCRITOME OF HUMAN GLIOBLASTOMA CELLS AND SUGGESTS NOVEL THERAPEUTIC STRATEGIES
Authors: Oishi Masahiro , Agyeman-Andoh Afua , Jung Mi-Yeon , Siddegowda Yeshavanth Banasavadi , Burton Eric , Brown Desmond 
Published: November 2023

Abstract

BACKGROUND
Glioblastoma is the most common malignant primary brain tumor. Despite standard-of-care therapy with maximal safe resection, concomitant chemoradiation followed by adjuvant chemotherapy, median survival is 18 months, and 5-year survival is 6.8%. The genetic complexity, ability to suppress host immune surveillance, and the blood-brain-barrier all contribute to the uniform fatality of the disease. Primary cilia are microtubule-based organelles that protrudes from the apical surface of all mammalian cells. They regulate several canonical signal transduction cascades important for development and pathogenesis. Glioblastoma cells are ciliated although the tumor downregulate genes associated with cilia formation and function. Contemporary studies suggest that the regulation of ciliogenesis is an important prognostic consideration. In this study, human glioblastoma cells were modified through stable lentiviral transduction to downregulate KIF3A (a gene required for ciliogenesis), or AURKA (a component of the ciliary disassembly complex). We then performed deep transcriptomic sequencing to determine how the overall transcriptome of human glioblastoma cells change in response to cilia-targeted genetic manipulation.

RESULTS
High-resolution confocal microscopy demonstrated that cilia were absent in KIF3A knockdown cells but abundant following loss of AURKA. Functional loss of primary cilia was confirmed with Gli2A RT-PCR following treatment with SAG (SHH pathway activator). There appeared to be rearrangement of the transcriptome with ciliary loss. Ingenuity Pathway Analysis demonstrated that ciliary loss resulted in the activation of pathways of glioblastoma and other cancer signaling pathways, tumor immune microenvironment pathways, cytokine signaling, and actin cytoskeletal rearrangement among several others.

CONCLUSION
Loss of primary cilia in glioblastomas activate several pro-cancer and immunosuppressive pathways. This suggests that targeting of primary cilia may lead to simultaneous loss of multiple glioblastoma phenotypes that contribute to the tumor’s evolutionary advantage. This may result in a novel paradigm of ‘ciliotherapeutics’ for glioblastomas and other cancers.
CSIG-24. LINEAR GRADING COEFFICIENT REVEALS EMBRYONIC DEVELOPMENT GENE SIGNATURE AS TREATMENT-INDEPENDENT PROGNOSTIC FACTOR IN IDH-MUTANT ASTROCYTOMA
Authors: Ghisai Santoesha , Hoogstrate Youri , Tesileanu Mircea , van Hijfte Levi , Vallentgoed Wies , de Heer Iris , Preusser Matthias , Gorlia Thierry , Sanson Marc , van den Bent Martin , French Pim 
Published: November 2023

Abstract

BACKGROUND
Since there is variation in prognosis within grade II/III and grade IV IDH-mutant astrocytomas, we sought to identify features that may aid further tumor grading.

METHODS
RNAseq was performed on IDH-mutant astrocytomas from the CATNON trial and overlaid with matching genome-wide methylation data. This dataset was extended by multi-omics data of IDH-mutant astrocytomas from the TCGA and GLASS-NL studies. We defined a linear grading coefficient (LGC) based on calibrated DNA methylation-based probability scores and performed differential gene expression (DGE) regression analysis on the LGC. Statistical analyses were intersected across the CATNON and TCGA cohorts ("discovery set") and validated on GLASS-NL. Single-nucleus RNA-sequencing (snRNAseq) data of high-grade IDH-mutant astrocytomas were utilized to explore the source of expression signals. Immunofluorescence was used to confirm findings on protein level.

RESULTS
DGE regression analysis revealed that higher-grade IDH-mutant tumors (high LGC) exhibited mRNA upregulation of key embryonic developmental transcription factors (HOX[A/C/D], NKX, PAX, and TBX). Although the vast majority of CpG sites in LGC high tumors were hypomethylated, homeobox genes were strongly hypermethylated in our discovery set. HOX gene clusters showed gene-ordered (differential) expression where e.g. HOXD10 &gt;D9 &gt;D8 &gt;D4 &gt;D1 and HOXA3 &gt;A7 &gt;A9 &gt;A13 suggesting derepression of enhancer sequences up/downstream of the gene cluster. Our expression-based embryonic development signature was positively correlated with, but not restricted to, the G-CIMP-low subtype and homozygous CDKN2AB deletion. The signature was prognostic (log-rank test) on both the discovery (CATNON: p&lt; 0.0005, TCGA: p&lt; 0.0005) and validation set (GLASS-NL: p&lt; 0.005). As our signature was developed on molecular data from primary resections, its prognostic value is treatment-independent. SnRNAseq on high-grade IDH-mutant astrocytomas indicated expression of embryonic development genes from tumor cells, not restricted to the stemness program.

CONCLUSION
Our study highlights upregulation of embryonic development genes as potential molecular mechanism associated with malignancy of IDH-mutant astrocytomas.
CSIG-25. OVERCOMING RESISTANCE TO THERAPIES TARGETING THE MAPK PATHWAY IN GLIOBLASTOMA
Authors: Bunda Severa , Aldape Kenneth , Zadeh Gelareh 
Published: November 2023

Abstract
Capicua (CIC) is a transcriptional repressor that inhibits expression of genes induced by receptor tyrosine kinase (RTK) activation. RTK/Ras/ERK signaling is one of the most tumorigenic pathways in cancer. In fact, the aggressive nature of the most common and lethal brain tumor, glioblastoma (GBM), has been attributed to hyperactivation of RTK. While CIC is mutated in other tumor types, we found that CIC has a tumor-suppressive function in GBM through an alternative mechanism. We show that Ras/ERK promotes degradation of CIC, resulting in de-repression of CIC targets and amplification of the tumorigenic Ras/ERK signal. Importantly, we show that sustained MEK/ERK inhibition fails to restore CIC protein levels desensitizing from upstream RTK/MEK/ERK inhibition. Our findings suggest the lack of efficacy of MEK/ERK inhibitors in GBM in the clinical context is due to the loss of CIC-mediated repression, hence exposing CIC as a potential therapeutic target in combination with MEK/ERK inhibitors. To uncover targetable pathways that stabilize CIC and sensitize towards MEK/ERK inhibitors in GBM we need to understand how CIC works and causes gene repression. We identified a novel CIC binding partner, Yin Yang 1 (YY1), a context dependent transcription factor important in GBM. We found that YY1/CIC binding co-regulates repression of genes downstream of RTK/Ras/ERK activation important in tumorigenesis. Importantly we uncovered a targetable pathway that leads to stabilization of CIC/YY1 on its target DNA which sensitizes towards MEK/ERK inhibition. These data provide insight into more effective therapeutic avenues to stabilize the CIC/YY1 co-repressor complex and re-sensitize towards RTK/Ras/MEK/ERK inhibition in GBM and likely in other tumors characterized with hyperactive Ras/ERK signaling and CIC loss.
CSIG-31. JAK/STAT PATHWAY CO-OPERATES WITH CIC-FUSIONS TO DRIVE CIC- REARRANGED SARCOMAS
Authors: Kaloti Ramneet , Bunda Severa , Zadeh Gelareh 
Published: November 2023

Abstract

BACKGROUND
CIC-rearranged sarcoma (CRS) is a rare disease driven by a specific fusion protein involving the CIC gene. The native CIC protein is a transcriptional repressor of the (RTK)/Ras/ERK signaling pathway, which is one of the most tumorigenic pathways in cancer. The most common rearrangement is with the double homeobox 4 (DUX4) transcription factor (CIC-DUX4), and others, such as CIC-NUTM1 fusions, have been identified in a subset of pediatric primitive neuroectodermal tumors. However, the molecular mechanisms by which CIC-fusions drive CRS remain unknown.

HYPOTHESIS
Preliminary data shows that CIC-DUX4/NUTM1 fusions activate JAK (cytokine receptors) and its downstream effector STAT1/3 (signal transducers and transcription factors). We hypothesize that the JAK/STAT1/3 signal transduction pathway cooperates with CIC-fusions to induce the expression of oncogenic transcription factors ETV1/4/5 and drive these sarcomas.

METHODS AND RESULTS
JAK1 is a potential target for CIC-fusions - We show high levels of JAK1/STAT1/3 activation in patient-derived CRS cell lines (NCC-SCC-89/C) as compared to other sarcoma cell lines without the fusion. JAK1 inhibition using Solicitinub and Ruxolitinib reduced phosphorylation of STAT1/3 as well as protein and mRNA expression of ETV1/4/5 and cell proliferation. JAK1/STAT1/3 inhibition in patient-derived CIC-DUX4 xenograft models- To evaluate the pre-clinical effect of targeting the JAK1/STAT1/3 pathway, A CRS cell line (NCC-SCC-89/C) were grafted into NSG mice. Ruxolitinib treatment significantly reduced tumor volume, STAT activation, and ETV1/4/5.

CONCLUSION
We show that the JAK1/STAT1/3 pathway plays a critical role in cooperating with CIC-fusions to drive CRS, providing insight into potential therapeutic avenues for these aggressive tumors.