bluuebunny/crossref_metadata_2025_split huggingface dataset:
CNSC-35. CANCERS GOT THE NERVE
Authors: S.Senga Sasi 
Published: November 2022

Abstract
Brain cancers carry a bleak prognosis despite the increase in our understanding of the disease. Brain tumours are in some ways a distinct entity in comparison to other types of tumours due to the distinct type of cell population in the brain tumour microenvironment. Sympathetic and parasympathetic nervous systems have been shown to exert a context-dependent effect on tumourigenesis. In 2021, I proposed neuronal signalling as a hallmark of cancer, albeit resection of specific nerves to hinder tumourigenesis is both challenging and may not result in the desired outcome. In order to add the nervous system to our armamentarium of therapeutic strategies against cancer, we may need to look beyond conventional methods of reducing synaptic plasticity such as with the use of anti-epileptic drugs. One among the strategy I propose is to utilize epigenetics to our advantage. Using lysine demethylase 5 specifically KDM5C to alter the synapticity in the brain tumour microenvironment is one way of exploiting the synaptic plasticity to our advantage against cancers. Additionally, metabolism intertwines the effects mediated by the nervous system which can be exploited to pivot the tumour-promoting effects of the nervous system towards tumour elimination.
MODL-27. PRECLINICAL INTERROGATION OF IMMUNOTHERAPY TREATMENT STRATEGIES IN GLIOBLASTOMA (GBM) USING A CLINICALLY RELEVANT DISEASE MODEL
Authors: Clerkin James , Connor Kate , White Kieron , Sweeney Kieron , Shiels Liam , Van Brussel Thomas , Arijs Ingrid , Lambrechts Diether , Maher Stephen , Marignol Laure , Prehn Jochen , O'Brien David , Byrne Annette 
Published: November 2022

Abstract
Clinically faithful pre-clinical models are essential for screening therapies and studying resistance mechanisms. Historically models have failed to predict response in the clinical setting. Current models seldom incorporate surgical resection, and commonly use young animals whose immune contexture differs from older patients. Here, we have established an orthotopic model, employing the syngeneic, mesenchymal-NFpp10a-cell line, in both young and aged mice. We have characterised the model's response to standard of care resection and temozolomide (TMZ) treatment. We have further studied response to anti-PD1 therapy (adjuvant and neoadjuvant). NFpp10a-Luc2 expressing cells were orthotopically implanted into C57BL/6 mice (aged { &gt; 18months} and young {6-8weeks}) and weekly bioluminescence imaging (BLI) performed to monitor tumour growth. Several therapeutic interventions were assessed to study tumour growth and survival: (1)surgical resection, (2)TMZ, (3)anti-PD1 (4)neoadjuvant anti-PD1. RNAseq, murine microenvironment cell population (mMCP) counter and gene ontology analyses characterised treatment related changed in the TME. We demonstrated survival advantage in aged mice undergoing resection (Resection:33.5 days vs Non-Resection:18 days;p=0.0166). Subsequently, we observed that TMZ and anti-PD1 monotherapy had no impact on NFpp10a-Luc2 growth (TMZ-overall:p=0.9001, and anti-PD1-overall:p = 0.7933) or survival (TMZ-overall:p = 0.3035, anti-PD1-overall:p= 0.6328). Neoadjuvant anti-PD1 treated mice demonstrated no survival advantage compared to IgG control (33-days vs 35-days:p = 0.9429). or BLI signal (p = 0.1703). NFpp10a-Luc2 forms immune-cold TME relative to commonly employed models. mMCP counter analysis demonstrates neoadjuvant anti-PD1 induced influx of CD8+-T cells, B cells, and monocytes into the TME compared to IgG control, and was associated with significantly upregulated CXCR3 chemokine receptor binding pathway on gene ontology analysis (p = 0.0045). Overall, we have, for the first time established and characterised response of the NFpp10a-Luc2-C57BL/6 model to resection, TMZ and anti-PD1 therapies. NFpp10a-Luc2 tumours demonstrate similar therapeutic resistance and TME profile compared to human mesenchymal GBM. The model may therefore be employed in future pre-clinical studies to guide clinical trials in mesenchymal GBM.
MODL-30. AN ENGINEERED TRANSGENIC MOUSE MODEL OF RETINOBLASTOMA
Authors: Liu Xiao , Pei Yanxin 
Published: November 2022

Abstract
Retinoblastoma, the most common intraocular tumor of childhood, was recently shown to comprise two major molecular subtypes. Subtype 1 includes most heritable forms, with germline mutation of RB1 and a cone-differentiated state. Subtype 2 is often non-hereditary, exhibits stemness features, increased expression of MYCN and its target genes, and a high risk of metastasis. Relative to subtype 1, subtype 2 tumors have a worse prognosis. To date, no mouse model has been available for studying subtype 2 disease. It is known that SHH pathway proteins including SHH, GLI1 and GLI2 are abnormally elevated in human retinoblastoma. We recently discovered that activation of GLI2 in the developing mouse retina leads to intraocular tumors that exhibit cellular and molecular features resembling human subtype 2 retinoblastoma with aberrant upregulation of MYCN and its target genes. Because MYCN is a downstream target of the SHH pathway, we hypothesize that inhibiting the SHH-GLI2-MYCN signaling axis may effectively treat subtype 2 disease. Using our GLI2 based mouse model of retinoblastoma, we will elucidate mechanisms underlying tumor initiation and progression, and evaluate the therapeutic potential of SHH and GLI2 inhibitors in preventing retinoblastoma. We will validate our mouse model findings using human retinoblastoma cell lines and patient-derived tumor xenografts. Our studies will yield new mechanistic insights into the development of subtype 2 retinoblastoma and identify novel molecular targets for early detection, treatment, and prevention of ocular tumors and associated metastatic disease.
MODL-31. PHOTORECEPTOR-POSITIVE PROGENITORS PUTATIVE CELLS OF ORIGIN IN MYC-DRIVEN GROUP 3 MEDULLOBLASTOMA
Authors: Zhao Miao , Mainwaring Oliver , Rosén Gabriela , Olsen Thale Kristin , Rijpkema Sanne , Sundström Anders , Weishaupt Holger , Furukawa Takahisa , Swartling Fredrik 
Published: November 2022

Abstract
The cell of origin of Group 3 medulloblastoma, the most malignant medulloblastoma subgroup, is currently unknown and remains controversial. Transcriptional profiling has revealed that Group 3 medulloblastomas are characterized by elevated expression of a photoreceptor program, which has not been described in the normal cerebellar development but is well characterized in the developing retina and pineal gland. We used lineage tracing and single-cell sequencing to compare normal brain development with tumor development in our previously generated MYC-driven transgenic mouse model (GMYC), where mice spontaneously develop Group 3 medulloblastoma after 4-6 months of age. We found that tumor cells emerged from progenitor cells where MYC overexpression drove the transformation of immature progenitor cells with photoreceptor pathway activity. Our data suggest that MYC-driven Group 3 medulloblastoma originates from progenitor cells expressing a photoreceptor program, which has implications for future research and the development of novel treatments targeting this devastating childhood malignancy.
CNSC-36. VRK1 IS A PARALOG SYNTHETIC LETHAL TARGET IN VRK2-METHYLATED GLIOBLASTOMA
Authors: Shields Julie , Meier Samuel , Bandi Madhavi , Ferdinez Maria Dam , Engel Justin , Mulkearns-Hubert Erin , Hajdari Nicole , Shen Binzhang , Hubert Christopher , Mitchell Kelly , Zhang Wenhai , Zhao Shan-chuan , Bejnood Alborz , Zhang Minjie , Sjin Robert Tjin Tham , Wilker Erik , Lathia Justin , Andersen Jannik , Chen Yingnan , Li Fang , Weber Barbara , Huang Alan , Emmanuel Natasha 
Published: November 2022

Abstract
Synthetic lethality — a genetic interaction that results in cell death when two genetic deficiencies co-occur but not when either deficiency occurs alone — can be co-opted for cancer therapeutics. A pair of paralog genes is among the most straightforward synthetic lethal interaction by virtue of their redundant functions. Here we demonstrate a paralog-based synthetic lethality by targeting Vaccinia-Related Kinase 1 (VRK1) in Vaccinia-Related Kinase 2 (VRK2)-methylated glioblastoma (GBM). VRK2 is silenced by promoter methylation in approximately two-thirds of GBM, an aggressive cancer with few available targeted therapies. Genetic knockdown of VRK1 in VRK2-methylated GBM cell lines and patient-derived models was lethal and resulted in decreased activity of the downstream substrate Barrier to Autointegration Factor (BAF), a regulator of post-mitotic nuclear envelope formation. VRK1 knockdown, and thus reduced BAF activity, caused nuclear lobulation, blebbing and micronucleation, which subsequently resulted in G2/M arrest and DNA damage. The VRK1-VRK2 synthetic lethal interaction was dependent on VRK1 kinase activity and was rescued by ectopic VRK2 expression. Knockdown of VRK1 led to robust tumor growth inhibition in VRK2-methylated GBM xenografts. These results indicate that inhibiting VRK1 kinase activity could be a viable therapeutic strategy in VRK2-methylated GBM.
MODL-41. ORGANOTYPIC BRAIN SLICE CULTURE PLATFORM AS A NOVEL PRE-CLINICAL MODEL FOR PATIENT DERIVED CELL LINES
Authors: Mann Breanna , Zhang Xiaopei , Bell Noah , Adefolaju Adebimpe , Dasari Rajaneekar , Hingtgen Shawn , Satterlee Andrew 
Published: November 2022

Abstract
The lack of experimentally tractable models that recapitulate brain structure and function represents a major impediment in the development of novel treatment options for brain cancer. In vitro assays, though fast and high throughput, produce artificial results which do not fully encompass the clinically relevant outcome. Low passage patient derived cell lines offer an advantage over immortalized cell lines in terms of relation to the clinical presentation. Low passage patient derived cell lines, however, show slower growth and decreased tumorgenicity. We have previously shown that the use of organotypic brain slice culture (OBSCs) can recapitulate growth patterns and migration which is seen in vivo. We have further expanded the OBSCs to study their use as a model for patient derived cell lines. Some cell lines such as MS21, a human glioblastoma, or IFF109-DMG, a human pediatric diffuse midline glioma, are simply supported over a four-day time period, whereas other lines such as IFF105-DIPG, a pediatric human diffuse intrinsic pontine glioma, can grow over 3-fold in a 4-day time period. Additionally, we can assess treatment response to a variety of clinically relevant chemotherapeutics. The decreased variability with the OBSCs allows for the assessment of minute differences in treatment response. Overall, these results suggest the OBSC with patient derived cell lines have the potential to be effective models to accelerate preclinical evaluation of therapeutics and guide drug development towards more effective treatment strategies.
CNSC-37. ATYPICAL GERMLINE MUTATIONS AND PRIMARY CNS TUMORS: A SINGLE-CENTER CASE SERIES AND LITERATURE REVIEW
Authors: Shah Trusha , Ruiz Amber , Ross Che , Dubard-Gault Marianne , Graber Jerome 
Published: November 2022

Abstract
A growing spectrum of germline mutations and their association with primary CNS tumors has been described over the last decade. These germline mutations are implicated in regulation of DNA integrity and repair, telomere maintenance, and cell cycle regulation resulting in aberrant cellular proliferation and immune surveillance evasion. To date, there are no well-defined guidelines for primary CNS tumor surveillance for these patients. Moreover, the exact role of traditional chemotherapy, immunotherapy, and radiation is unclear. We present a single-institution case series of adult patients with primary CNS tumors with atypical germline mutations and literature review. The most common germline mutations encountered involved heterozygous mutations of one of the mismatch repair (MMR) genes (MSH2, PMS2, MLH1). All patients developed high-grade gliomas defined as astrocytoma or glioblastoma WHO grade 4 based on the WHO 2021 classification. Germline mutations involving RAD51C, POT1, IDH1/2, MutyH, NTHL1, PALB2, and CHEK2 were associated with gliomas of variable grades and molecular subtypes. Non-glial tumors, including atypical rhabdoid tumors, medulloblastomas, hemangioblastomas, and meningiomas were found in association with germline SMARCB1, ATM, BRCA1, and CHEK2 mutations respectively. Review of the existing literature and knowledge obtained from our case series suggests several important concepts: (1) there is an increased risk of both glioma and non-glial tumor types in several atypical germline mutations, (2) multiple risk genes or variants of unknown significance likely contribute to primary brain tumor formation, (3) germline MMR mutations associated with high-grade glioma may be MMR gene-specific with potential increased risk of resistance and/or disease progression in the presence of alkylating agents such as temozolomide, (4) several germline mutations may increase risk of secondary tumor development after radiation, and (5) the role of screening for atypical germline mutations and subsequent disease surveillance remain unanswered.
STEM-01. GLIOMA STEM CELLS ACTIVATE PLATELETS BY PLASMA-INDEPENDENT THROMBIN PRODUCTION TO PROMOTE GBM TUMORIGENESIS
Authors: Sloan Anthony , Lee-Poturalski Christine , Hoffman Harry , Harris Peggy , Elder Theresa , Cioffi Gino , Barnholtz-Sloan Jill , Rich Jeremy N , Jankowsky Eckhard , Gupta Anirban Sen , Sloan Andrew 
Published: November 2022

Abstract
The interaction between platelets and cancer cells has been underexplored in solid tumor models that do not metastasize, for example glioblastoma (GBM) for which metastasis is rare. Histologically, it is known that glioma stem cells (GSCs) 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. While platelets are known to promote progression of other tumors, mechanisms by which platelets influence GBM oncogenesis are unknown. Here, we aimed to understand how the bidirectional interaction between platelets and GSCs drives GBM oncogenesis. Male and female NSG mice were transplanted with patient derived GSC lines and treated with antiplatelet and anti-thrombin inhibitors. Immunofluorescence, qPCR, and Western blots were used to determine expression of coagulation mechanism in GBM tissue and subsequent GSC lines. We demonstrate that GSCs co-opt and activate platelets to promote GBM tumor progression. GSCs endogenously produce all coagulation factors of the intrinsic and extrinsic cascade generating thrombin and activating platelets in the absence of plasma. Conversely, inhibition of platelet activation and of thrombin production by GSCs abrogates platelet-mediated GSC self-renewal and growth (p&lt; 0.0005). Similarly, inhibiting intratumoral thrombin production and function decreases tumor formation in vivo (p&lt; 0.005). These studies challenge and revise the longstanding view that the complete coagulation cascades are found only in the liver and plasma demonstrating that cancer stem cells readily execute a highly liver-specific gene expression program that is mechanistically linked to GBM oncogenesis. We show that cancer cells can co-opt non-cancer cells to promote tumor growth, by uncovering the preferential relationship between platelets and GSCs that drive GBM malignancies and identifies a therapeutically targetable novel interaction.
STEM-06. NUCLEAR STRUCTURE MAINTAINS GLIOBLASTOMA STEM CELLS
Authors: Duan Tingting , Bhargava Shruti , Rich Jeremy 
Published: November 2022

Abstract
Glioblastoma stem cells (GSCs) contribute to therapeutic resistance, promote tumor angiogenesis, and evade anti-tumor immune responses. We and others have shown that GSCs display differential regulation of their epigenetic landscapes and metabolic profiles and contribute to the striking cellular heterogeneity and complex tumor microenvironments. Here, we find that GSCs undergo dramatic changes in chromatin organization and nuclear morphology upon differentiation. Leveraging unbiased RNA sequencing and protein profiling screens comparing GSCs and differentiated glioma cells, we identified nuclear membrane molecular regulation that defines nuclear size and lipid regulation. Genetic or pharmacologic targeting of nuclear envelope function reduced cancer stem cell proliferation, self-renewal, and in vivo tumor growth. Collectively, we define a novel role of the nuclear envelope in maintaining chromatin state and cancer stem cell self-renewing, informing the development of novel potential therapeutic paradigms for glioblastoma.
STEM-07. DEFINING THE ROLE OF HUMAN ENDOGENOUS RETROVIRUS-K (HML-2) IN THE GLIOBLASTOMA STEM-CELL NICHE
Authors: Shah Ashish , Rivas Sarah , Doucet-Ohare Tara , Govindarajan Vaidya , DeMarino Catherine , Ampie Leo , Banasavadi-Siddegowda Yeshavanath , Maric Dragan , Garcia-Montojo Marta , Suter Rob , Lee Myoung-Hwa , Walbridge Stuart , Zaghloul Kareem , Steiner Joseph , Johnson Kory , Gilbert Mark , Heiss John , Nath Avindra 
Published: November 2022

Abstract
Human Endogenous Retrovirus (HERV) are ancestral viral relics that comprise nearly 8% of the human genome. Although silenced in normal tissues, the most recently integrated provirus HERV-K (HML-2) can be pathologically reactivated in certain cancers. Here, we report pathological expression of HML-2 transcripts in human malignant gliomas in cerebrospinal fluid (HERV-K DNA/RPP30=35.2±8.8 vs 23.1±6.7, n=18, p=0.02) and tumors (HERV-K RNA/HPRTmean=1.15±0.2 vs. 0.5±0.2, p=0.01, n=20) compared to epilepsy controls. Aberrant HML-2 expression corresponded to a unique stem-cell niche using multivoxel automated segmentation. Using a tailored single-cell RNA sequencing pipeline to detect retrotransposons, we identified glioblastoma cellular populations with elevated HML-2 transcripts in neural progenitor-like cells that can drive cellular plasticity (ANOVA, multiple-testing correction, p&lt; 0.001). Using CRISPR technology, we demonstrate that HML-2 is critical to maintenance of glioblastoma stemness and tumorigenesis in both glioblastoma neurospheres and intracranial orthotopic murine models (OS: 26 days vs. 18.6, p=0.0008, n=20). Downregulation of HERV-K using CRISPRi reduces the glioblastoma neurosphere formation (2-way ANOVA, p&lt; 0.0001). and HERV-K env, Polymerase, OCT4 and Nestin transcripts (2-way ANOVA p&lt; 0.001). Using Chromatin Immunoprecipitation, we determined that this interaction in gliomas is likely mediated by the nuclear transcription factor OCT4 which binds to an HML-2 specific Long-Terminal Repeat (LTR5Hs). Moreover, using Transmission Electron Microscopy, we discovered that some glioma stem-cells form immature retroviral virions in glioblastoma. Inhibiting HML-2 expression with nucleoside reverse transcriptase inhibitors reduces extracellular reverse transcriptase (One-way ANOVA, p&lt; 0.05), tumor viability (IC50=75.8-123.1 uM), and pluripotency (One-way ANOVA, p&lt; 0.01). Our results suggest that HML-2 is overexpressed in the cancer stem-cell niche of glioblastoma. Since persistence of glioblastoma stem-cells is considered responsible for treatment resistance and recurrence, HML-2 may serve as a unique therapeutic target in glioblastoma.
STEM-10. TEMPORAL MULTI-MODAL SINGLE-CELL ANALYSES REVEAL DYNAMIC INTERACTIONS BETWEEN GLIOBLASTOMA AND CAR-T CELLS AND IMMUNOLOGIC MODULATORS OF CANCER STEM CELL STATE
Authors: Zhang Daniel , Wang Xin , Sun Yusha , O'Rourke Donald , Ming Guo-Li , Song Hongjun 
Published: November 2022

Abstract
CAR-T cell therapy is a promising new immunotherapy for a number of difficult-to-treat cancers, however, it has yet to yield broad success in glioblastoma (GBM). In particular, tumor heterogeneity presents a major therapeutic challenge, and a detailed understanding of the complex interplay between different neoplastic, non-neoplastic, and CAR-T cells is critical for developing better treatments. Using a patient-derived GBM organoid model of CAR-T cell therapy, we performed single-cell multi-omics to examine the longitudinal dynamics of the adaptive tumor response, changes in cell states, and evolution of cell-to-cell interaction networks. We find that all tumor cell types - neoplastic and non-neoplastic - respond to CAR-T cell activity, and they generate to an initially anti-tumor, but subsequently pro-tumor and immune-inhibitory microenvironment, which is accompanied by eventual CAR-T cell dysfunction and exhaustion. Unexpectedly, CAR-T cell activity also leads to attenuation of glioma stem-like states in both antigen-positive and antigen-negative neoplastic cells and reduces their proliferation via diffusible factors, of which IFNɣ is required but not sufficient. These findings are supported by analyses in patient samples from CAR-T cell therapy clinical trials, and they are consistent across both de novo and recurrent tumors with different somatic mutational landscapes. Our study unravels how the complex heterogeneity of GBM interacts with CAR-T cell therapy, and we identify previously unappreciated possibilities to affect antigen-negative neoplastic cells in ways that may be further augmented for enhanced therapeutic efficacy.
STEM-11. POLYAMINE METABOLISM AND INFLAMMATORY STATE CONTROL A VIRAL MIMICRY-DRIVEN QUIESCENT PHENOTYPE IN GLIOMA STEM CELLS (GSCS)
Authors: Chesnelong Charles , Charton Connor , Dirks Peter 
Published: November 2022

Abstract
The rate limiting enzyme of the polyamine pathway, SAT1, is significantly upregulated in non-cycling GSCs. However, higher SAT1 expression predicts poorer survival in GBM suggesting a role in quiescence and recurrence post-treatment. Treating GSCs with N1N11-Diethylnorspermine (DENSpm) recapitulates SAT1 upregulation and triggers a chemoprotective, long-term reversible growth arrest, while not affecting expression of stem, differentiation, nor senescence-associated markers. Remarkably, DENSpm strongly induces double-stranded RNA in GSCs. Interestingly, S-Adenosyl methionine (SAM) is an essential aminopropyl donor for polyamine biosynthesis. We found a significant correlation between DNA methylation, SAM, and polyamines across GSCs suggesting that SAM depletion may cause epigenetic and post-transcriptional alterations leading to re-activation of endogenous retroviral elements (ERVs) and viral mimicry-driven quiescence. However, while we confirmed DENSpm-induced SAM depletion, we did not detect DNA, histone, nor RNA demethylation. Noteworthy, ERVs are the most accessible transposable elements in GSCs indicative of a poised state. Furthermore, the correlation between expression of ERVs and interferon stimulated genes reveals a spectrum of viral mimicry amongst GSCs. Using a larger cohort of GSCs and hfNSCs, we identified three DENSpm response subgroups. A resistant subgroup comprised of cells able to proliferate through treatment, a reversible one whereby cells become quiescent and readily re-enter cell cycle post-treatment, and an irreversible consisting of cells that enter a deep quiescent state which they cannot escape. Importantly, we found that DENSpm response correlates with the cell's basal inflammatory state and the activity of viral defense pathways. These results indicate that a viral mimicry-driven quiescence may be specific to slower-growing neurodevelopmental GSCs, while more proliferative, inflammatory-poised GSCs are impervious to these additional cues. We propose that polyamine metabolism, glioma stem cell hierarchy and tumour inflammatory context play a central role in regulating quiescence and have important clinical implications in the initial response to treatment, aggressiveness, and ultimately recurrence of GBM.