bluuebunny/crossref_metadata_2025_split huggingface dataset:
DDRE-14. HEMP DERIVED EXTRACELLULAR VESICLES (EVS): A POTENTIAL ANTI-GLIOMA THERAPY
Authors: Azari Hassan , Koopaei Nasser Nassiri , Nouri Mohammad-Zaman , Hall Jesse D , Denslow Nancy D , Schmittgen Thomas D , Reynolds Brent A 
Published: December 2020

Abstract

INTRODUCTION
Extracellular vesicles (EVs) have been harvested from many plant sources, some of which have anti-cancer effects and some could be used as therapeutic nanodelivery vectors. Hemp plant is a natural source of cannabinoids, of which delta 9-tetrahydroxicannabinol (THC) and cannabidiol (CBD) have proven anti-cancer proprieties.

HYPOTHESIS
We hypothesized that hemp EVs are enriched in cannabinoids and their application will reduce glioblastoma (GBM) tumor progression.

APPROACH
EVs were isolated from the hemp plant using ultracentrifugation. Nanotracking analysis, electron microscopy and liquid chromatography tandem mass spectrometry (LC-MS/MS) were utilized to characterize EVs. GBM cell lines were cultured in the neuropshere assay to evaluate hemp EVs anti-glioma effects. Fluorescent-labelled EVs were used to evaluate their brain tissue distribution in orthotopic patient-derived GBM xenografts.

RESULTS
Hemp EVs have a median diameter of 112.6nm with a typical lipid-bilayer structure. LC-MS/MS have shown that while cannabidiolic, cannabigerolic, and tetrahydroxicannabinolic acids represent 69.1 ± 2.1%, 19.1 ± 1.6%, 6.5 ± 0.54% of the total cannabinoids in hemp EVs, CBD and THC only make 4.75 ± 0.26%, and 0.5 ± 0.3%. Hemp EVs are potent anti-glioma agents with a 7-day LD-50 of 1.04µM and 2.4µM [based on EVs total cannabinoid content] for KR-158 and L0 GBM lines, respectively. Compared to the vehicle, overnight incubation of L0 cells with 1µM hemp EVs significantly reduced GBM cell migration (630.3 ± 61.43 vs 143.7 ± 8.7). Intranasal administration of hemp EVs led to a widespread distribution in tumor bearing brain including GBM tumor core.

CONCLUSION
Based on these results, hemp EVs with enriched cannabinoid content exert antiglioma effect in-vitro and when delivered intranasally, are widely distributed throughout the brain and within the tumor of PDX animals. Further experiments are ongoing to address the impact of nasally-delivered hemp EVs on tumor progression and compare to the application of purified acidic cannabinoids.
DDRE-30. HIGH-THROUGHPUT DRUG SCREENING OF FDA-APPROVED ANTINEOPLASTIC DRUGS FOR THE TREATMENT OF AGGRESSIVE MENINGIOMAS
Authors: Jungwirth Gerhard , Yu Tao , Liu Fang , Warta Rolf , Unterberg Andreas , Herold-Mende Christel 
Published: December 2020

Abstract
The management of aggressive meningiomas remains challenging due to limited treatment options besides surgical removal and radiotherapy. High recurrence rates and lack of effective chemotherapies may be reasons for the unfavorable prognosis of these patients. Consequently, there is an urgent need to identify effective therapeutic agents. For this purpose, we performed a high-throughput screening utilizing a drug library consisting of 147 FDA-approved antineoplastic drugs on the anaplastic meningioma cell line NCH93 using CellTiter-Glo (Promega). Based on the lowest IC50, the top 5 drugs were selected including Bortezomib, Carfilzomib, Omacetaxine, Ixabepilone, and Romidepsin. Validation of candidate compounds was performed in Ben-Men-1 (grade I), NCH93 (grade III), and IOMM-Lee cells (grade III) using crystal violet assay. Dose-curve analysis revealed IC50 values in the lower nanomolar range for all compounds and all cell lines (0.2 – 16.2 nM). To further substantiate our findings, cell proliferation assessed by manual counting was significantly reduced by up to 90% by each candidate drug at 10xIC50 after 48 h (P &lt; 0.001). Furthermore, cell migration was inhibited up to 60% by all candidate drugs at the respective IC50 (P &lt; 0.05). However, colony formation was only significantly reduced by Bortezomib and Carfilzomib (P &lt; 0.001). The impact of the drugs on cell cycle and apoptosis was analyzed by flow cytometry using Annexin V/PI staining. All candidate drugs induced cell cycle arrest at G0/G1 or G2/M phase (P &lt; 0.001) and subsequently induced apoptosis. Among them, Bortezomib exhibited the most pronounced effect by up to 80% of apoptotic cells (P &lt; 0.001). In summary, by utilizing a high-throughput drug screening we were able to identify Bortezomib, Carfilzomib, Omacetaxine, Ixabepilone, and Romidepsin as potent antineoplastic agents for the treatment of aggressive meningiomas.
DDRE-31. EVALUATION OF HIGHLY POTENT AND SELECTIVE SINGLE-MOLECULE DUAL EGFR/PI3K INHIBITORS IN ADULT AND PEDIATRIC HIGH-GRADE GLIOMA
Authors: Gangadharan Achintyan , Sun Yusha , Bailey Cavan , Carter Trever , Espejo Alexsandra , Whitehead Christopher , Leopold Judith , Chandra Joya 
Published: December 2020

Abstract
High grade gliomas (HGG) carry poor prognosis with median survival rates under 15 months post diagnosis. Due to dysregulation of kinase signaling pathways within these tumors, targeted kinase inhibition has been considered as a promising clinical strategy. However in HGG, many single-agent inhibitors of EGFR or PI3K have shown limited response due to activation of compensatory signaling. Single-molecule multikinase inhibitors may decrease resistance, present a single pharmacokinetic dosage profile, and reduce risks of multi-agent toxicities, supporting this strategy over dual drug combination approaches. To test this concept, a panel of inhibitors exploiting known binding modes of structurally-related ATP binding site inhibitors of EGFR/PI3K were synthesized and characterized. Of these, MTX-241 was least likely to act as a substrate for drug efflux proteins such as P-glycoprotein. Treatment of MTX-241 in a panel of eight human adult and pediatric HGG lines showed strong cytotoxic potency measured by growth inhibitory activity, with IC50s in the &lt; 10 µM range. Tumor selectivity of MTX-241 was observed, with normal human astrocytes (NHA) nearly insensitive to MTX-241 even at &gt;100 µM. MTX-241 was significantly more potent than clinically relevant inhibitors targeting EGFR/RTKs (gefitinib, lapatinib, dasatinib, imatinib) or PI3K (alpelisib, idelalisib). Synthesis and evaluation of a new series of compounds based on MTX-241 structure, but optimized for improved stability is ongoing. Our data suggests that a dual inhibitor of EGFR and PI3K, represents a viable therapeutic strategy in adult and pediatric HGG. Future studies will focus on evaluation of in vivo efficacy in tumor bearing mouse models.
EPCO-02. MOLECULAR CHARACTERIZATION OF TWO NOVEL MPNST SUBGROUPS IDENTIFIES THERAPEUTIC OPPORTUNITIES
Authors: Suppiah Suganth , Mansouri Sheila , Mamatjan Yasin , Liu Jeff , Patil Vikas , Bhunia Minu , Mehani Bharati , Suppiah Ying , Karimi Shirin , Singh Olivia , Aldape Kenneth , Largaespada David , Zadeh Gelareh 
Published: December 2020

Abstract
Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive Schwann-cell derived sarcomas. These tumors are resistant to all current therapies, with exception to gross total surgical resection, and unresectable or metastatic tumors are considered incurable. Our understanding of the molecular alterations driving malignant transformation is limited, and to date, targeted therapies have proven ineffective. In this study, we leverage multi-platform genomic and epigenomic profiling of human MPNSTs and neurofibromas to identify targetable molecular pathways that lead to malignant transformation. Unsupervised consensus hierarchical clustering of the top 20K most variable methylated probes yielded seven stable and robust subgroups that are clinically relevant. The high-grade MPNSTs formed two distinct methylation-based clusters (MPNST-G1 and MPNST-G2). MPNST-G1 had worse prognosis compared to MPNST-G2 (0.6 years versus 1.4 years, p &lt; 0.05). PTCH1 loss or SMO gain was prevalent in MPNST-G1 compared to MPNST-G2 (75% vs 12.5%, p &lt; 0.05). In addition, MPNST-G1 harbored PTCH1 CpG island promoter hypermethylation in (87.5% vs 12.5%, p &lt; 0.001). Transcriptome profiling recapitulated the two distinct MPNST subgroups. We next demonstrated that that RB1 signaling pathways are aberrant in both MPNST-G1 and MPNST-G2. However, SHH pathway activation is observed in MPNST-G1, while WNT/CCND1/ ß-catenin pathway activation is observed in MPNST-G2. Network-based drug-disease proximity analysis identified SMO inhibitors as a potential FDA approved drug as a potential targeted therapy. To determine if SHH pathway activation is sufficient for malignant transformation, we knocked out PTCH1 in immortalized neurofibroma cells lines. In 3 different cell lines with PTCH1 knockout, we observed induction of a malignant phenotype, with increased cellular proliferation and invasion. Most importantly, in-vitro and in-vivo models confirm that targeting the SHH pathway, with sonidegib, was effective in inhibiting tumor growth proving SMO inhibition to be a novel therapeutic option in these lethal cancers.
EPCO-03. REPORT OF NTRK FUSION IN A PEDIATRIC PATIENT WITH SPINAL GANGLIOCYTOMA
Authors: Gupte Avanti , Toll Stephanie , Marupudi Neena , Gorsi Hamza 
Published: December 2020

Abstract

BACKGROUND
Gangliocytomas are rare WHO grade 1 central nervous system tumors of neuronal/ mixed neuronal-glial classification that most commonly occur in the cerebrum, favoring the temporal lobe. They are also reported in cerebellum in the setting of Lhermite-Duclos disease. Spinal gangliocytomas are exceedingly rare, constituting 3–10% of reported pediatric cases. Maximal safe surgical resection is the mainstay of therapy, as response to irradiation or traditional chemotherapy is variable. Given the rarity of these tumors, little is known about the molecular makeup or the role of targeted therapy in this population.

CASE
Our patient presented as a 7-year-old male with thorocolumbar scoliosis. A magnetic resonance imaging (MRI) of his spine incidentally demonstrated a heterogeneously enhancing, expansile solid and cystic intramedullary thoracic mass from T6 through T11. MRI brain did not show any intracranial mass. He subsequently underwent a laminectomy with laminoplasty for the intramedullary mass. Histopathologic analysis confirmed a WHO grade I gangliocytoma with moderately cellular abnormal central neural tissue composed of irregular clusters and cords of mature-appearing neurons in a coarse neuropil background. Because of the unusual location and presentation of his disease, molecular analysis including DNA and RNA sequencing was performed which revealed a somatic BCR-NTRK2 fusion.

DISCUSSION
NTRK gene fusions are known oncogenic drivers, reported with varying frequency in many pediatric and adult tumors. They are reported in &lt; 1% of adult head and neck cancers but greater than 90% of congenital infantile fibrosarcomas. NTRK fusions are seen in pediatric brain tumors like infantile high grade gliomas, however they have not been previously reported in gangliocytoma. As TRK inhibitors are efficacious in treating a number of NTRK-rearranged malignancies, this novel finding provides a therapeutic option for NTRK fusion positive gangliocytoma where complete surgical resection is not safely possible.
EPCO-05. LOSS OF THE H4 LYSINE METHYLTRANSFERASE KMT5B DRIVES INVASION / MIGRATION BY DEPLETING H3K27me3 AT LOCI OTHERWISE RETAINED IN H3K27M MUTANT DIPG CELLS
Authors: Kessler Ketty , Mackay Alan , Molinari Valeria , Tari Haider , Burford Anna , Sottoriva Andrea , Vinci Maria , Jones Chris 
Published: December 2020

Abstract
Diffuse intrinsic pontine glioma (DIPG) and other diffuse midline glioma (DMG) are characterised by K27M mutations in histone H3 variants. The major functional consequence is a global loss of the repressive mark H3K27me3, causing a raft of transcriptional changes promoting tumorigenesis, although certain key loci retain trimethylation, such as CDKN2A/B. We recently identified subclonal loss-of-function mutations in the H4 lysine methyltransferase KMT5B to be associated with an enhanced invasion/migration, but the mechanism by which this occurred was unclear. Here we show by ChIP-seq using patient-derived subclonal DIPG models and CRISPR-Cas9 depletion that loss of KMT5B (or KMT5C) causes a paradoxical increase in global levels of H4K20me3 in promoters and regulatory regions, only ablated by knocking out both enzymes. Loss of KMT5B alone further causes loss of the majority of otherwise retained H3K27me3 loci in DIPG cells, although CDKN2A/B itself was spared. De-repression occurred at bivalent loci marked by H3K4me3 and had elevated gene expression by RNAseq; these were significantly enriched for genes involved in chromatin remodelling and invasion/migration, the latter including MMP9/MMP24. Phenotypic assessment of the models in vitro by high-throughput imaging demonstrated significantly increased invasion and migration in association with either KMT5B or KMT5C loss, but not both. Quantitative proteomic assessment of the secretome identified factors by which a minority of KMT5B-deficient cells may signal to promote motility of the neighbouring populations. These data suggest a previously unrecognised trans-histone (H4/H3) interaction in DIPG cells with a potentially profound effect on their diffusely infiltrating phenotype.
EPCO-07. LEVERAGING TRANSCRIPTOME SEQUENCING AND MATHEMATICAL MODELING TO INVESTIGATE GLIOBLASTOMA-MACROPHAGE INTERACTIONS
Authors: Urcuyo Javier , Hawkins-Daarud Andrea , Massey Susan , Bruce Jeffrey , Canoll Peter , Tran Nhan , Hu Leland , Swanson Kristin 
Published: December 2020

Abstract
Glioblastoma (GBM) is the one of the most aggressive and common primary brain malignancies, with a poor median overall survival of less than 15 months. While the immune system is activated and brain-resident microglia and blood-derived macrophages combat the tumor, the tumor can convert some microglia and macrophages to instead exhibit an immune-suppressive phenotype. These co-opted immune cells are thereby termed ‘glioma-associated microglia and macrophages’ (GAMMs), as they allow for continued tumor growth. However, limited clinical data has been collected to understand this phenomenon. As a result, we have collected spatially-distributed image-localized biopsies from a cohort of patients and performed RNA sequencing on each sample. Correlations between normalized RNA counts of genetic markers for macrophages (i.e., CD68, CD163), tumor populations (i.e., SOX2, OLIG2), and key cell functions (i.e., KI67, CASP3) were analyzed. To further investigate the temporal effects that GAMMs have on GBM growth, we proposed the Proliferation-Invasion-Macrophage (PIM) model. This system of partial differential equations incorporates the proliferative and invasive behavior of GBM, as well as populations for both ‘healthy’ and ‘glioma-associated’ macrophages. By exploring the parameter space, we classified the various dynamics of tumor progression and how they relate to the immune response. With further insights of the interactions between GBM and macrophage populations, we can begin to parameterize the model on a patient-specific basis and provide insights to personalized immunotherapies and other novel immune-targeted treatments.
EPCO-11. IN VIVO FUNCTIONAL GENOMIC SCREEN IDENTIFIES WISP1 AS AN OVEREXPRESSED DRIVER OF GLIOBLASTOMA
Authors: Dasgupta Pushan , Gumin Joy , Pettazzoni Piergiorgio , Barthel Floris , Deem Angela , Dey Prasenjit , Huang-Hobbs Emmet , Sulman Erik , Verhaak Roel , Lang Frederick , Draetta Giulio 
Published: December 2020

Abstract
There is a tremendous need to identify new genetic drivers of glioblastoma which can serve as potential therapeutic targets. In order to find new drivers, we leveraged genomic datasets to conduct a context specific in vivo functional genomic screen of overexpressed and/or amplified genes in GBM. We identified WISP1, a secreted extracellular matrix protein, to be an overexpressed driver in GBM. Overexpression of WISP1 was able to drive tumor growth in various in vivo models. Knockdown of WISP1 with shRNAs resulted in reduced colony formation in vitro and reduced tumor growth in vivo. Rescue experiments validated that the shRNAs were on target. Functional characterization of the protein revealed that the TSP module is necessary for the phenotype. Intriguingly, overexpression of WISP1 lacking the signal peptide module for secretion resulted in a strong phenotype. Co-culture and conditioned medium experiments further supported a secretion independent intracellular role of WISP1 in GBM. Though WISP1 is a secreted protein we have found some basal localization in the cytosol. Overall, we have revealed WISP1 to be a driver of GBM with possible therapeutic potential as a target. This study has expanded our understanding of WISP1 by supporting a new role as a driver in GBM which can function in a non-canonical manner in the cytosol. Overall, we have revealed WISP1 to be a driver of GBM with possible therapeutic potential as a target.
EPCO-13. GENOME-WIDE ASSOCIATION STUDY IN INDIVIDUALS OF ASHKENAZI JEWISH ANCESTRY IDENTIFIES NOVEL RISK LOCI FOR GLIOMA
Authors: Ostrom Quinn , Byun Jinyoung , Amos Christopher , Claus Elizabeth , Bondy Melissa 
Published: December 2020

Abstract
Population stratification, or systematic differences in allele frequencies between subpopulations, can distort the results from genome-wide association studies (GWAS). While GWAS are usually conducted within continental (e.g. European) ancestry groups, sub-groups may have specific population histories that result in enrichment for risk or protective alleles for complex disease. In this analysis, we examined genetic risk for glioma in a US population with predominantly Ashkenazi Jewish (AJ) ancestry. Genotyping data were obtained from three prior glioma case-control studies. Best-guess assignment to one of seven subcontinental European ancestry groups was performed using AIPS (https://github.com/biomedicaldatascience/AIPS). Out of a total of 6,416 cases and 7,441 controls across all three studies, 202 cases (3% of all cases, 63% GBM) and 403 controls (5% of all controls) were assigned to the AJ ancestry group. Unconditional logistic regression was performed for by study (adjusted for age and first two principal components) and then studies were combined using fixed effects meta-analysis. No associations reached genome-wide significance (p&lt; 5x10-8), including those detected in prior pan-European GWAS. A nominally significant association was detected on chromosome 17 in ASPA (rs9904040, MAF=20%, p=2.61x10-6, Odds ratio=2.22 [95% confidence interval=1.59–3.09]) which is in linkage equilibrium (r2=0.0013) with the previously detected glioma risk SNP in TP53 (MAF=0.3% in this analysis, p=0.8801) in the European population. In our prior pan-European meta-analysis (Melin et al., 2017, this SNP was non-significant (p=0.0620). This study failed to replicate many previously identified glioma risk alleles, likely due to diminished power due to small sample size. We did identify a novel risk allele on chromosome 17 in ASPA, which encodes for aspartoacylase (which catalyzes deacylation of N-acetyl_L-aspartic acid). Larger sample sizes identified via targeted recruitment are necessary in order to fully characterize genetic risk for glioma in this population, including assessment of rare (MAF&lt; 5%) risk allele associations.
EPCO-15. TUMOR TREATMENT WITH IONIZING RADIATION IS ASSOCIATED WITH A CLINICALLY RELEVANT DELETION SIGNATURE
Authors: Kocakavuk Emre , Anderson Kevin , Johnson Kevin , Varn Frederick , Amin Samirkumar , Barthel Floris , Verhaak Roel 
Published: December 2020

Abstract
Diffuse gliomas are highly aggressive brain tumors that invariably relapse despite treatment with chemo- and radiotherapy. Treatment with alkylating chemotherapy can drive tumors to develop a hypermutator phenotype. In contrast, the genomic effects of radiation therapy (RT) remain unknown. We analyzed the mutational spectra following treatment with ionizing radiation in sequencing data from 190 paired primary-recurrent gliomas from the Glioma Longitudinal Analysis (GLASS) dataset and 2249 post-treatment metastatic tumors from the Hartwig Medical Foundation. We identified a significant increase in the frequency of small deletions following radiation therapy that was independent of other factors. These novel deletions demonstrated distinct characteristics when compared to pre-existing deletions present prior to RT-treatment and deletions in RT-untreated tumors. Radiation therapy-acquired deletions were characterized by a larger deletion size (GLASS and metastatic cohort, P = 1.2e-02 and P = 8e-11, respectively; Mann-Whitney U test), an increased distance to repetitive DNA elements (P &lt; 2.2e-16, Kolmogorov-Smirnov test) and a reduction in microhomology at breakpoints (P = 3.2e-02, paired Wilcoxon signed-rank test). These observations suggested that canonical non-homologous end joining (c-NHEJ) was the preferred pathway for DNA double strand break repair of RT-induced DNA damage. Furthermore, radiotherapy resulted in frequent chromosomal deletions and significantly increased frequencies of CDKN2A homozygous deletions. Finally, a high burden of RT-associated deletions was associated with worse clinical outcomes (GLASS and metastatic cohort, P = 4.7e-02, HR = 2.59 [95% CI: 1.01, 6.60] and P = 2.5e-02, HR = 1.43 [95% CI: 1.05, 1.94], respectively; multivariable Cox regression), suggesting that effective repair of RT-induced DNA damage is detrimental to patient survival and that inhibiting c-NHEJ may be a viable strategy for improving the cancer-killing effect of radiotherapy. Taken together, the identified genomic scars as a result of radiation therapy reflect a more aggressive tumor with increased levels of resistance to follow up treatments.
EPCO-16. LACTIC ACID IS AN EPIGENETIC METABOLITE THAT DRIVES GLIOBLASTOMA SURVIVAL AND GROWTH
Authors: Torrini Consuelo , Nguyen Trang , Shu Chang , Mela Angeliki , Humala Nelson , Mahajan Aayushi , Karpel-Massler Georg , Bruce Jeffrey , Canoll Peter , Siegelin Markus 
Published: December 2020

Abstract
Glioblastoma (GBM) is the most common primary malignant brain tumor with an unfavorable prognosis and a reprogrammed metabolism. While tumors utilize glucose, there are other carbon sources at their disposal. Originally considered as a waste product of glucose catabolism, lactate accumulates to a significant amount in tumor tissue. We launched our studies with the central hypothesis that lactate is metabolized by GBM cells to promote their survival via modulation of the epigenome. We showed that lactate rescued patient-derived xenograft (PDX) GBM cells from nutrient deprivation mediated cell death and inhibition of growth. Transcriptome analysis, Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq), and CHIP-seq. showed that lactic acid exposure entertained a signature of cell cycle progression, oxidative phosphorylation (OXPHOS) and MYC target expression. LC/MS analysis demonstrated that U-13C-Lactate elicited substantial labeling of TCA-cycle metabolites, acetyl-CoA and histone protein acetyl-residues in PDX derived GBM cells. Given that acetyl-CoA is pivotal for histone acetylation we observed a dose-dependent elevation of histone marks (e.g. H3K27ac), which was rescued by genetic and pharmacological inhibition of lactic acid-uptake, ATP-citrate lyase, p300 histone-acetyl-transferase and OXPHOS, resulting in reversal of lactate mediated protection from cell death or facilitation of GBM growth. CHIP-seq. analysis demonstrated that lactic acid facilitated enhanced binding of H3K27ac to gene promoters and cis-regulatory elements (e.g. super-enhancers). Consistently, ATAC-seq. analysis highlighted enhanced accessibility of the chromatin by lactic acid. Finally, we assessed whether lactic acid is actively metabolized in vivo, utilizing an orthotopic PDX model of GBM. In a combined tracer experiment (U-13C-glucose and 3-C13-lactate), we made the fundamental observation that lactic acid carbons were predominantly labeling the TCA cycle metabolites over glucose, implying a critical role of lactic acid in GBMs and establishing lactic acid metabolism as a novel drug target for GBM that may be targeted with epigenetic drugs.