bluuebunny/crossref_metadata_2025_split huggingface dataset:
TAMI-71. EFFECTS OF THE TREATED MICROENVIRONMENT ON GLIOMA CELL PROPERTIES IN AN ORGANOTYPIC BRAIN SLICE MODEL
Authors: Pantazopoulou Vasiliki , Berg Tracy , Pietras Alexander 
Published: November 2021

Abstract
Glioblastoma is the most aggressive primary brain tumor. Despite treatment all patients invariably recur. Treatment resistance is attributed to the presence of glioma stem-like cells. Initially thought to be a distinct and static cell population, it is becoming increasingly clear that the glioma stem-like cell phenotype represents one of many cellular states and that glioma cells show plasticity between stem-like and non-stem like states. These plastic cell states are affected by the tumor microenvironment. In our lab we have shown that irradiated and hypoxic astrocytes increase the stem-like cell properties of glioma cells. In this study, we aim to evaluate how the treated microenvironment alters glioma cell properties and use ex vivo organotypic brain slices generated from tumor bearing and tumor naïve mice to assess all aspects of the microenvironment. We first characterized organotypic brain slices cultured in different oxygen tensions. We saw that tumor-bearing slices survive for at least 14 days in culture at 21%, 5% or 1% oxygen tension (O2). Tumor cells were more viable in all culture conditions and timepoints compared to non-tumor cells. Moreover, we found that astrocytes seem to be attracted to tumor areas in both 5% and 1% O2 cultures. We then used the organotypic glioma slice culture system to address how preconditioning the microenvironment using radiation or temozolomide affects the properties of glioma cells that are seeded in these pretreated, tumor naïve slices. We saw that fluorescently labelled glioma cells seeded in treated slices can be isolated after two days of culture in the slices and can be used for downstream analyses, such as temozolomide or radiation treatment and colony formation. This study will elucidate the effect of the treated microenvironment on glioma cell properties by using the medium throughput method of organotypic slice cultures.
TAMI-76. INTEGRATED MULTI-OMICS REVEAL INTRATUMOUR HETEROGENEITY AND NOVEL THERAPEUTIC TARGETS IN PAEDIATRIC EPENDYMOMA
Authors: Pandele Alina , Woodward Alison , Lankford Sophie , Macarthur Donald , Kamaly-Asl Ian , Barrett David , Grundy Richard , Kim Dong-Hyun , Rahman Ruman 
Published: November 2021

Abstract
Ependymoma (EPN) is the second most common malignant paediatric brain tumour with a five-year survival rate of only 25% following relapse. While molecular heterogeneity between EPN tumours is well understood, little is known concerning spatially-distinct intratumour heterogeneity within patients. In this context, we present a multi-omics integration of expression data at transcriptomic and metabolomic levels revealing intratumour heterogeneity and novel therapeutic targets. Surgically resected ependymoma tissue from two epigenetic subgroups, posterior fossa-A (PF-A) and supratentorial RELA, were first homogenised and polar metabolites, lipids and RNA simultaneously extracted from the same cellular population. Using liquid chromatography-mass spectrometry (LC-MS) and RNAseq 115 metabolites and 1580 upregulated genes were identified between the two subgroups, therefore validating previously reported genetic clustering of these two subtypes. Sampling of anatomically distinct regions was performed between eight PF-A EPN patients and multi-omic data was compared across 28 intratumour regions, with at least 3 different regions per patient. Integration of genes and metabolites revealed 124 dysregulated metabolic pathways, encompassing 156 genes and 49 metabolites. A large number of interactions occur in the gluconeogenesis and glycine pathways in 6 out of 8 patients, putatively representing therapeutically relevant ubiquitous metabolic pathways critical for EPN survival. Each anatomical region also presented at least one unique gene-metabolite interaction demonstrating heterogeneity within and across PF-A EPN tumours. A subset of the eight most prevalent genes across patients (GAD1, NT5C, FBP1, FMO3, HK3, TALDO1, NT5E, ALDH3A1) were selected for in vitro metabolic assays using 10 repurposed cytotoxic agents against PF-A EPN cell lines derived from intratumour regions of the same patient. 5/8 genes map within the gluconeogenesis metabolic pathway, further highlighting its significance within PF-A EPN. This is the first instance where multi-omic data integration and intratumour heterogeneity has been investigated for paediatric EPN revealing novel potential targets in the context of gene-metabolite correlations.
TAMI-80. CELLULAR METABOLISM IN DIFFUSE INTRINSIC PONTINE GLIOMA
Authors: Ijare Omkar , Manalo Jeanne , Sharpe Martyn , Baskin David , Pichumani Kumar 
Published: November 2021

Abstract
Diffuse intrinsic pontine glioma (DIPG) is an aggressive form of brain tumor in children, comprising &gt;10% of all pediatric brain tumors. The median survival after diagnosis is &lt; 1 year. Since DIPG tumors infiltrate brainstem and pons, they are inoperable. Currently radiotherapy is the mainstay of treatment, and there is a great need for novel therapies for the treatment of DIPG. Cellular metabolism plays a key role in carcinogenesis, unravelling active metabolic pathways in DIPG would help in developing targeted therapies. Glucose and glutamine are the two major nutrients necessary for the growth and proliferation of cancer cells. In this study, we have investigated the glucose and glutamine metabolism in SF8628 DIPG cells using 1H/13C NMR and GC-MS based metabolic flux analysis. SF8628 cells were grown in DMEM containing 11.0 mM glucose, supplemented with 10% FBS, and 2.0 mM glutamine at 37 °C under humidified air and 5% CO2. When cells reached confluency (replicates = 4), treated with 11.0 mM [U-13C]glucose or 4.0 mM glutamine in DMEM (supplemented with 10% FBS). After 24 h, cells were harvested for NMR/GC-MS analysis. The 13C-isotopomer analysis revealed that SF8628 cells produced 25.26 ± 10.63% acetyl-CoA from [U-13C]glucose which is ~3.7 times higher than that produced from GBM cells (6.83 ± 0.76%; our previous work), suggesting that DIPGs are metabolically very active. [U-13C]glutamine metabolism showed that DIPG cells also have an active TCA cycle metabolism (citrate M+4; 40.07 ± 1.06%) and moderately active reductive carboxylation pathway (citrate M+5; 10.59 ± 1.13%). Inhibition of both glycolytic and glutaminolysis pathways will be valuable in developing treatment strategies for DIPGs and these studies are in progress.
TMOD-02. GENERATION OF A NOVEL MOUSE MODEL FOR BRAIN TUMORS OF THE DNA METHYLATION CLASS “GBM MYCN”
Authors: Schoof Melanie , Göbel Carolin , Holdhof Dörthe , Al-Kershi Sina , Schüller Ulrich 
Published: November 2021

Abstract
DNA methylation based classification of brain tumors has revealed a high heterogeneity between tumors and led to the description of multiple distinct subclasses. The increasing subdivision of tumors can help to understand molecular mechanisms of tumor development and to improve therapy if appropriate model systems for preclinical research are available. Multiple recent publications have described a subgroup of pediatric glioblastoma which is clearly separable from other pediatric and adult glioblastoma in its DNA methylation profile (GBM MYCN). Many cases in this group are driven by MYCN amplifications and harbor TP53 mutations. These tumors almost exclusively occur in children and were further described as highly aggressive with a median overall survival of only 14 months. In order to further investigate the biology and treatment options of these tumors, we generated hGFAP-cre::TP53 Fl/Fl ::lsl-MYCN mice. These mice carry a loss of TP53 and show aberrant MYCN expression in neural precursors of the central nervous system. The animals develop large forebrain tumors within the first 80 days of life with 100 % penetrance. These tumors resemble human GBM MYCN tumors histologically and are sensitive to AURKA and ATR inhibitors in vitro. We believe that further characterization of the model and in vivo treatment studies will pave the way to improve treatment of patients with these highly aggressive tumors.
TMOD-04. T-TYPE CALCIUM CHANNELS DRIVE GLIOBLASTOMA INITIATION AND PROGRESSION
Authors: Dube Collin , Zhang Ying , Jr Myron Gibert , Mulcahy Elizabeth , Ottolini Matteo , Xu Esther , Sorot Aditya , Perez-Reyes Edward , Sonkusare Swapnil , Abounader Roger 
Published: November 2021

Abstract
Glioblastoma is the most common primary malignant brain tumor with a dismal median survival of 15 months. Calcium signaling regulates a plethora of cellular processes making it an ideal target for therapeutic intervention. Our group identified T-type calcium channels (TTCCs) as upregulated in GBM cells, stem cells and human tumors. Analysis of the Cancer Genome Atlas (TCGA) demonstrates for the first time that &gt;20% of GBM patients exhibit mutation, amplification or mRNA upregulation of TTCCs. TCGA and Chinese Glioma Genome Atlas (CGGA) data analyses demonstrate that patients with alterations in TTCC trend toward worse survival compared to normal TTCC expression. Our group utilized an FDA repurposed TTCC blocker Mibefradil to demonstrate inhibition of TTCCs decreases cancer associated signaling, transcription, malignancy parameters and in vivo tumor growth. Mibefradil treatment sensitized Gliomas stem like cells (GSC) xenografts to temozolomide (TMZ) chemotherapy and radiotherapy. To elucidate the roles of the individual TTCCs in vivo we created RCAS/Tva-shTTCC mice for silencing of Cav3.1 and Cav3.2. The silencing of the TTCCs individually decreased tumor growth as measured by MRI and H&E staining. Silencing of TTCCs extended survival of mice in vivo. Silencing of TTCC decreases proliferation (Ki67) and increases apoptosis (Caspase 3). Our findings suggest T-type calcium channels contribute to tumor initiation and progression.
TMOD-11. A PREDICTIVE MICROFLUIDIC MODEL OF VASCULARIZED GLIOMA TUMORS TO ASSESS TRAFFICKING OF THERAPEUTICS ACROSS THE BLOOD-BRAIN BARRIER
Authors: Hajal Cynthia , Straehla Joelle , Offeddu Giovanni , Safford Hannah , Hammond Paula , Kamm Roger 
Published: November 2021

Abstract
Although important distinctions exist between subtypes of HGGs, all patients fare poorly with a 5-year survival of &lt; 5%. The infiltrative growth of HGGs imposes significant challenges to treatment, with the presence of residual microscopic tumors post-surgery and hampered chemotherapeutic penetration due to the blood-brain barrier (BBB), a highly selective endothelium regulating transport between blood and brain. Moreover, current preclinical models are costly, low throughput, and often fail to predict drug performance in the clinic. There is thus an increasing need for in vitro models of HGG tumors, surrounded by a realistic BBB vasculature, to recapitulate therapeutic trafficking. To this end, we engineered a high-throughput microfluidic model composed entirely of human cells where HGG spheroids are embedded in a BBB microvascular network of endothelial cells, pericytes, and astrocytes. Tumors co-opt the vasculature as observed in patients and BBB permeability measurements with perfused dextran demonstrate unaltered paracellular transport near and far from the tumors. Lipoprotein receptor protein 1 (LRP1) expression, however, is increased near HGG spheroids. These results were leveraged to synthesize layer-by-layer nanoparticles with angiopep-2 ligands exhibiting high affinity to LRP1 for targeted delivery. Angiopep-2 nanoparticles displayed the largest permeability across the BBB near tumors compared to bare nanoparticles. Knock-down of LRP1 in the BBB-HGG model decreased angiopep-2 nanoparticle permeability confirming LRP1-mediated transport. We next assessed the therapeutic implications of our findings by encapsulating cisplatin in the particles. Administration of cisplatin-loaded angiopep-2 nanoparticles resulted in significant tumor shrinkage with targeted apoptosis in the tumor area compared to bare cisplatin nanoparticles or free cisplatin which damaged the surrounding healthy BBB vessels. Validations in orthotopic tumor-bearing mice are ongoing. In summary, we propose a novel preclinical model with a functional human BBB vasculature surrounding HGG tumors for high-throughput investigations and validate that this platform predicts the transport of targeted drug-loaded carriers.
TMOD-17. A NOVEL GLIOBLASTOMA INVASION MODEL USING HUMAN BRAIN SLICE CULTURES
Authors: Ravi Vidyha , Joseph Kevin , Beck Jürgen , Schnell Oliver , Hofmann Ulrich , Heiland Dieter Henrik 
Published: November 2021

Abstract

OBJECTIVE
Glioblastoma (GBM) is among the most common of malignant brain tumours, with a median post-surgical survival of less than one year. Over the past several decades, therapies that appeared promising in mice models have failed during clinical trials due to the differences encountered during translation of research from model organisms to humans. To partially mitigate these difficulties in translation, we present a human cortical organotypic culture based GBM model, which allows us to manipulate individual components of the tumour environment in order to investigate the influence of different cell types in the immunosuppressive tumour microenvironment.

METHODS
Human neocortical tissue (at least 2 cm away from the tumour core) or entry cortex from epilepsy surgery guided by intraoperative neuro navigation, was cultured for up to 14 days post resection using an optimized medium. The cultured tissue was further injected with patient derived human GBM cells to create an ex vivo human model of glioblastoma model. The role of astrocytes in the tumour microenvironment was studied using microglia loss of function model.

RESULTS
Our established human neo-cortical slice model can recapitulate an in-vivo characteristics of glioblastoma from functional and imaging aspect. Our data corroborate differences between astrocytes in human and murine models in different reactive states, shows that the glioblastoma microenvironment can be difficult to be accurately modelled using murine models. Results from our human microglia depletion model, provided ample evidence that complex interaction of astrocytes and microglia cells, promotes an immunosuppressive environment in Glioblastoma by releasing high concentration of IL10 and TGFbeta (p&lt; 0.001).

CONCLUSION
Our model therefore has potential applications to the fields of neuroscience, neuro-oncology, and pharmacotherapy.
TMOD-23. MODELING PEDIATRIC BRAIN CANCER WITH HUMAN ORGANOIDS
Authors: Tiberi Luca 
Published: November 2021

Abstract
Among children/infant brain tumors, Medulloblastoma (MB) is the most common and stands as a cause for a high percentage of morbidity and mortality among patients During the past few years, studies on human MB have uncovered the existence of four major MB groups: WNT, SHH, Group3 and Group4. Patients with Group3 MB currently have the worst outcome among the four groups, and nearly 50% are metastatic at the time of diagnosis. In the last 3 years in our laboratory, we have developed a novel pediatric Medulloblastoma organoid model. We generated human iPSC-derived cancer organoids upon c-MYC/OTX2 and C-MYC/Gfi1 overexpression, mimicking human MB genetic alterations. Furthermore, the use of DNA methylation signature in combination with MB-specific markers analysis indicates that our organoid-based cancer model recapitulates several features of human MB. Now, we are taking advantage of this technology to produce novel brain cancer organoids that we are using to address cancer biology questions.
TMOD-26. MYC OVEREXPRESSION AND SMARCA4 LOSS IN GRANULE CELL PRECURSORS COOPERATE TO DRIVE MEDULLOBLASTOMA FORMATION IN MICE
Authors: Göbel Carolin , Holdhof Dörthe , Schoof Melanie , Kresbach Catena , Schüller Ulrich 
Published: November 2021

Abstract
Mutations in SMARCA4 are frequently identified in medulloblastoma, the most common pediatric malignant brain tumor. However, the functional significance of these mutations and their suitability as a therapeutic target remain largely unclear. Medulloblastomas are divided into 4 subgroups according to their localization, molecular biology, and clinical course: WNT, SHH, Group 3, and Group 4. Group 3 medulloblastomas are associated with the poorest outcome and frequently show amplifications of the oncogene MYC. Additionally, SMARCA4 is mutated in around 15 % of cases. The few mouse models developed for this entity so far all involve the overexpression of MYC, mostly in combination with other drivers. However, none of these models include alterations in Smarca4. In our approach, we combined an overexpression of MYC with a loss of SMARCA4 in granule cell precursors, which successfully induced tumor formation in mice. For this purpose, granule cell precursors were isolated from 7-day-old Math1-creER T2 ::Smarca4 fl/fl pups after tamoxifen induced loss of SMARCA4. MYC overexpression was achieved by lentiviral transduction and transduced cells were transplanted into immunodeficient CD1 nu/nu mice. Preliminary results within a small cohort showed tumor formation in 5/19 transplanted mice (26 %) after 6 months. Immunohistochemically, tumors all stained negative for SMARCA4. In a next step, additional cohorts will elucidate if tumor development is indeed accelerated by or even dependent on the loss of SMARCA4. Additionally, the neoplastic potential of tumor cells will be verified with the aid of secondary recipient mice. To evaluate to what extent the generated tumors are comparable to human Group 3 medulloblastomas, tumors will be extensively analyzed on a morphological, transcriptional, and epigenetic level. Altogether, we hope to establish a suitable mouse model for SMARCA4 mutated Group 3 medulloblastoma that will help to elucidate the role of SMARCA4 in tumor development and to identify new therapeutic targets.
TMOD-30. NTRK2 SPLICE VARIANT, TRKB.T1, LINKS NEUROBIOLOGY, EMBRYONIC DEVELOPMENT, AND ONCOGENESIS
Authors: Pattwell Siobhan , Arora Sonali , Nuechterlein Nicholas , Zager Michael , Loeb Keith , Cimino Patrick , Holland Nikolas , Bolouri Hamid , Ozawa Tatsuya , Haffner Michael , Cao Junyue , Shendure Jay , Holland Eric 
Published: November 2021

Abstract
Temporally regulated alternative splicing choices are vital for proper development yet the wrong splice choice may be detrimental. Here we highlight a novel role for the neurotrophin receptor splice variant TrkB.T1 in neurodevelopment, embryogenesis, transformation, and oncogenesis across multiple tumor types in both humans and mice. TrkB.T1 is the predominant NTRK2 isoform across embryonic organogenesis and is highly expressed in a wide range of adult and pediatric tumors. Further, forced expression of TrkB.T1 causes multiple solid and non-solid tumors in mice in the context of tumor suppressor loss. These results highlight a unique role for the neurotrophin receptor splicing in development and oncogenesis and underscore the need for considering alternative splicing and transcript level data in neuroscience, developmental biology, and oncology research.
BRMP-03. Pituitary carcinoma: a case of dramatic response to immunotherapy (ipilimumab + nivolumab) after failure with temozolomide
Authors: Shah Sanjit , Manzoor Saima , Rothman Yehudit , Hagen Matthew , Prater Luke , Golnik Karl , Mahammedi Abdelkader , Lin Andrew , Bhabhra Ruchi , Forbes Jonathan , Sengupta Soma 
Published: November 2021

Abstract

INTRODUCTION
Pituitary carcinoma (PC) accounts for just 0.1% of all pituitary tumors, often recurs following resection, and has a median reported survival of 1 year. Current treatment guidelines are not standardized but combine surgical resection, radiation therapy, and chemotherapy [1]. Temozolomide is the only chemotherapeutic with documented effectiveness, and the only recommended agent for aggressive pituitary carcinomas in ESE clinical guidelines [3]. CASE: A 57-year-old male presented with visual deterioration over a three-month period. Ophthalmologic evaluation revealed bitemporal visual field deficits. MRI brain W/WO demonstrated a sellar mass suspected to be pituitary macroadenoma with displacement of the stalk and optic nerve impingement (Figure 1a). The patient underwent stereotactic endoscopic transsphenoidal resection of the mass [2]. Postoperative MRI demonstrated gross total resection (Figure 1b). Pathology revealed a sparsely granulated corticotroph-adenoma with malignant transformation (early in-situ PC). Immunohistochemistry showed LOE of MLH1 and PMS2 in the tumor cells; Genetic analysis revealed MGMT methylation. Proton therapy was recommended given the elevated Ki67 index (75%) and p53 positivity. Before radiotherapy, there was no evidence of residual tumor or metastasis radiographically. He received 6600cGy of radiation over 33 fractions. Surveillance MRI showed recurrence at 21 months postoperatively, and temozolomide was initiated. However, MRI demonstrated marked progression after 3 cycles, and at 44 months, he developed a new 6th nerve palsy (Figure1c). Next-generation sequencing using the MSK-IMPACT platform identified somatic mutations in MLH1 Y548lfs*9 and TP53 R337C[4]. Immunotherapy with ipilimumab/nivolumab was initiated [5], and the patient noted resolution of his third nerve palsy soon after. MRI demonstrated a dramatic response with only minimal residual tumor burden (Figure1d).

CONCLUSION
PC is a rare tumor with frequent recurrence and a short median expected length of survival. Here we demonstrate the utility of immunotherapy in a single case report of PC. This treatment helped our patient survive well beyond the expected median life expectancy of this aggressive disease.
CNTM-02. Regulation of glioma-network integration by tumor mediated secretion of TSP-1
Authors: Negussie Mikias , Krishna Saritha , Hervey-Jumper Shawn 
Published: November 2021

Abstract
Glioma exists in the complex neural circuitry of the brain, making the interface between neoplastic and healthy neurons and glia potentially damaging to long range neural networks and stimulatory to tumor growth. Thrombospondin-1 (TSP-1), an astrocyte derived neurogenic factor expressed by glia of the normal brain, has been found to be upregulated in intratumoral regions with high network functional connectivity (HFC). This modified cell signaling represents cancer cell hijacking of normal physiology with direct impact on tumor biology. There is emerging evidence that neuronal activity influences glioma proliferation and gliomas promote neuronal hyperexcitability. In humans, we have recently shown that bidirectional cellular interactions between gliomas and neurons alter cognitive circuit dynamics and ultimately patient survival. Previously, a subpopulation of human high-grade glioma cells which are enriched for tumor cells with synaptogenic potential were identified (HFC-IHDwtGBM). We plan to study the mechanisms of TSP1 signaling in three different established glioma models (1) HFC-IDHwtGBM hippocampal neuron co-culture, (2) HFC-IDHwtGBM + induced neuron organoids, (3) patient derived xenografts (PDX) for in vivo GCaMP calcium imaging. This project aims to test the hypothesis that increased TSP-1 secretion from HFC-IHDwtGBM cells plays a central role in the maintenance of an invasive and proliferative tumor phenotype when compared with LFC-IHDwtGBM PDX. We hope our study guides future work focused on preventing the infiltration of tumor cells into healthy brain tissues.