bluuebunny/crossref_metadata_2025_split huggingface dataset:
TMIC-35. IDH1 MUTATION IN GLIOMA REPROGRAMS EARLY MYELOID DIFFERENTIATION IN THE BONE MARROW (BM) TO PRODUCE NON-IMUNESUPPRESSIVE NEUTROPHILS
Authors: Alghamri Mahmoud , Castro Maria , Lowenstein Pedro , Kamran Neha , Kadiyala Padma , Avvari Ruthvik , Zhang Li 
Published: November 2019

Abstract
Gliomas are the most common primary brain tumors; patients exhibit a poor prognosis. Mutations in isocitrate dehydrogenase (mIDH) are present in most patients with lower grade glioma (LGG), and are correlated with better prognosis and survival. We postulated that mIDH1 induces epigenetic reprogramming leading to alteration in immune cells’ function. To examine the role of mIDH1 in the tumor immune microenvironment (TME), we generated LGG glioma models using the sleeping beauty system (Koschmann et al., 2016, Nunez et al., 2019). We show that mIDH1 gliomas exhibit increased levels of CD11b+ Gr1+ myeloid derived suppressor cells in the tumor, BM, circulation and spleen of mice. We found that mIDH1 modifies the cytokines’ repertoire in the glioma microenvironment altering the phenotype and function of the tumor infiltrating CD45+/CD11b+/Gr-1+ myeloid cells, rendering them non-immunosuppressive. Production of these cells results from activation of the granulocytic differentiation program in the BM. This novel mechanism is mediated by tumor-derived granulocyte-colony stimulating factor (G-CSF) which elicits expansion and differentiation of hematopoietic stem cells, skewing hematopoiesis towards the immature myeloid lineage. Moreover, mIDH1 glioma derived G-CSF causes mobilization of hematopoietic stem cells (HSCs) and myeloid progenitors (MPs) from BM to spleen. Blocking G-CSF in mIDH1 bearing mice significantly restored HSCs, and MPs frequencies in the spleen to levels encountered in wtIDH1 glioma. Interestingly, blocking G-CSF restored the inhibitory function of the granulocytic CD11b+ Gr-1+ in mIDH1, and shortened the median survival (MS) of mIDH1 bearing mice to the same MS encountered in wtIDH1 glioma. Our results provide insights into novel epigenetic alterations triggered by mIDH1 which regulate myeloid cells’ heterogeneity and immunosuppression; a feature that can be harnessed to develop novel immunotherapeutic strategies.
TMIC-42. LOCAL TISSUE METABOLOMICS BASED BIOMARKERS OF RESPONSE TO THERAPY FOR GLIOBLASTOMA
Authors: Rajani Karishma , Carlstrom Lucas , Jacobs Joshua , Schroeder Mark , Olson Ian , Wang Xuewei , Sarkaria Jann , Burns Terry 
Published: November 2019

Abstract
Glioblastoma (GBM) is a common deadly malignant brain cancer of the central nervous system (CNS), with a median survival of 12–15 months. Scientific advancements are lacking in developing effective therapies for both primary GBM, as well as secondary GBMs, that typically originate as malignant transformation of lower-grade isocitrate dehydrogenase (IDH) 1-mutant tumors. The unique metabolomic profile of IDH1-mutant tumors may present opportunities to develop biomarker signatures of therapeutic efficacy. Microdialysis is an extracellular fluid sampling collection technique utilizing a perfused semipermeable catheter to permit diffusion of molecules between brain interstitium and the perfusate. We hypothesized that microdialysis may identify a metabolomics-based biomarker response to therapy in IDH1-mutant tumors. To test this hypothesis, orthotopic xenografts were generated from two patient-derived GBM lines harboring mutations in IDH1. Perfusates were collected from intra-cranial tumors in aythmic nude mice sampled at baseline and 72h post treatment with temozolomide, an oral alkylating agent used to treat IDH1-mutant gliomas, compared with vehicle treatment, and TMZ-treated non-tumor bearing animals. Perfusates were analyzed via unsupervised metabolomic profiling using both gas and liquid chromatography-mass spectrometry (GC/LC-MS). Tumor specific metabolites such as carnitine and pyruvic acid were detected in microdialysate from tumor bearing mice compared to non-tumor bearing mice. Microdialysis is a feasible technology to identify metabolomics-based biomarker in IDH1-mutant PDX. This work is complemented by parallel analysis of non-IDH1-mutant and TMZ resistant xenografts to yield predictive in vivo tissue biomarkers of drug responsiveness translatable to clinical practice.
TMIC-43. ROLE OF EXTRACELLULAR FERRITIN HEAVY CHAIN PROTEIN IN GLIOBLASTOMA MULTIFORME
Authors: Pandya Bhavyata , Ravi Vagisha , Connor James 
Published: November 2019

Abstract
Increased expression of Ferritin heavy chain (FHC) protein has been associated with poor prognosis in Glioblastoma Multiforme (GBM) which is one of the most aggressive and common types of brain cancer. GBM patients have also been found to have increased extracellular ferritin levels, in their serum and cerebrospinal fluid (CSF), which are lowered once the source/tumor has been resected. Extracellular FHC can function as an iron delivery protein, and increasing amount of iron has been known to contribute to tumor initiation and proliferation. To study the effect of extracellular FHC in GBM cells we used patient derived GBM, CD133+ cancer stem cells (GSCs) from the pro-neural (T3691) and mesenchymal (T387) subtypes. Using recombinant FHC, conjugated with quantum dots (QD), we observed significant increase in cellular viability and intracellular uptake of FHC by the GSCs in a dose dependent manner. Our lab has previously shown that extracellular FHC interacts with T-Cell Immunoglobulin Mucin Receptor 1 (Tim-1) in the human oligodendrocytes. In order to determine if GSCs express the Tim-1 receptor we first confirmed its expression on GSCs using immunoblotting and immunocytochemistry. To test if FHC interacts with Tim-1, we performed knockdown of Tim-1 using siRNAs. However, the siRNA was not able to downregulate the Tim-1 receptors. Next, we exposed the GSCs to Sema4A, which has been shown in our previous studies to interact with Tim-1 receptor on human oligodendrocytes and is toxic to oligodendrocytes. The GSCs however were not affected by the saturable concentration of Sema4A. Thus, through this study we have shown the expression of potential FHC receptors on GSCs and a robust effect of H-ferritin on GSCs proliferation. Further experiments are warranted in this direction to understand this extracellular FHC uptake pathway and its role in GBM cell proliferation.
TMIC-44. IL-1 ANTAGONIST ANAKINRA INHIBITS GLIOBLASTOMA PROLIFERATION BY ANTAGONIZING THE PROINFLAMMATORY MICROENVIRONMENT
Authors: Effinger David , Hübner Max , Wu Tingting , Thon Niklas , Kreth Friedrich-Wilhelm , Kreth Simone 
Published: November 2019

Abstract

INTRODUCTION
The recombinant IL-1 receptor antagonist anakinra prevents binding of IL-1 to its receptor and blocks IL-1β-mediated proinflammatory signaling. It is currently used in the treatment of autoinflammatory diseases. As inflammation is a major driver of malignancy, we hypothesized that anakinra – by ameliorating the inflammatory tumor environment – might be capable to mitigate glioblastoma (GBM) progression.

METHODS
T98G GBM cells were cultivated with PBMC, separated by cell culture inserts with or without anakinra and incubated 48h in 5% O2 mimicking the GBM microenvironment. T-cells were obtained by magnetic bead isolation. mRNA expression levels were measured by quantitative Real-Time-PCR (qRT-PCR). Cytokine production was assessed by ELISA. Cell proliferation was analyzed by flow cytometric quantification of Ki-67 protein expression. Anakinra has been provided by Swedish Orphan Biovitrum AB (Sweden). Results are presented as mean±SEM, p-Values were calculated using Student’s t-test.

RESULTS
After administration of anakinra, mRNA expression levels of the inflammatory and proangiogenic genes IL-1β, COX-2, CCL2 and IL-8 were reduced in T98G (-64%±19.1%, -56.2%±21.3%, -87.1%±28.8%, -91.7%±27.2%, n=7, p< 0.05). Surprisingly, no changes of these targets were detectable in PBMC. However, in T-cells, anakinra induced mRNA expression of Th2 transcription factor GATA3 and the antiinflammatory cytokines IL-4 and IL-10 (+6,7%±4,6%, +36,1%±22,9%, +69,1%32,8%, n=10, p< 0.05). The expression of the protumorigenic genes IL-22, IL-17 as well as IFNγ was dramatically repressed (-63.2%±21.9%, -88.1%±21.7%, -85.6%±45.2%, n=10, p< 0.05), protein secretion of IL-22 and IFNγ was strongly blocked (-36.3%±9.1%, -13.9%±0.5%, n=6, p< 0.05). Importantly, treatment with anakinra markedly attenuated GBM cell proliferation (-20.1%±5%, n=4, p< 0.05).

CONCLUSION
Anakinra indeed puts the brake on proinflammatory signaling pathways in GBM cells and simultaneously promotes a shift towards an anti-inflammatory T-cell phenotype. As a result, GBM proliferation is diminished. Hence, administration of anakinra might be an interesting and novel therapeutic approach to reduce Glioblastoma aggressiveness.
TMIC-48. MACROPHAGE DEPLETION COMBINED WITH RADIATION IN A PRECLINICAL MEDULLOBLASTOMA MODEL
Authors: Crotty Erin , Brasel Ken , Pakiam Fiona , Girard Emily , Olson James 
Published: November 2019

Abstract

BACKGROUND
Radiation induces a measurable immune response, yet this anti-tumor immunity is often suboptimal at eliminating residual brain tumor cells. Medulloblastomas, along with other pediatric brain tumors, tend to recur in the primary resection bed following irradiation. Infiltrating macrophage within the tumor (TAM) are radioresistant immune cells that may limit the effectiveness of radiotherapy and promote tumor regrowth through their immunosuppressive and pro-tumorigenic functions. Therefore, we explored whether CSF-1 receptor (CSF1R) inhibition, and essentially TAM depletion, could augment radiation and/or reduce local recurrence.

METHODS
Selected CSF1R inhibitors were tested on both human and mouse macrophage in vitro. In vivo studies were performed on a patient-derived orthotopic xenograft (PDOX) model of Group 3 medulloblastoma, Med411-FH. Macrophage depletion was achieved using the anti-murine CSF1R antibody, AFS98, injected intra-peritoneally 10 days prior to, concurrently, and after radiation.

RESULTS
CSF1R antibodies and small molecule tyrosine kinase inhibitors were effective at stanching macrophage survival in culture. In a PDOX medulloblastoma model, both classes of CSF1R inhibitors were effective at reducing macrophage in the brain after approximately 10 days of administration, with maximal effect of 90% depletion achieved after 21 days. In a combinatorial study of AFS98 and irradiation, TAM depletion conferred a very modest effect on tumor growth (p=0.003) and had no effect on overall survival when combined with radiation (p=0.86). Interestingly, we did observe a trend toward reduction in metastatic spinal disease following radiation in the AFS98-treated cohort.

CONCLUSION
CSF1R antibody administration effectively eliminated macrophage and microglia in the brain and spine, suggesting adequate blood-brain barrier penetration in our xenograft model. While CSF1R inhibition combined with radiation was ineffective at prolonging survival, further studies are needed to investigate a modest effect on brain tumor growth and an observed (yet not statistically significant) difference in metastatic spinal recurrence in drug-treated animals.
TMIC-51. GBP1 RECRUITS MACROPHAGES TO PROMOTE GLIOBLASTOMA GROWTH
Authors: Chen Lili , Li Ming 
Published: November 2019

Abstract
Guanylate binding protein 1 (GBP1) is an interferon-inducible large GTPase which plays a key role in tumor development, but the molecular mechanism is poorly understood. Here we investigated whether GBP1 could influence the tumor microenvironment in glioblastoma, the most common and malignant brain tumor. We found that forced expression of GBP1 in glioblastoma cells induced macrophage polarization toward an M2 phenotype via upregulating Chemokine (C-C motif) ligand 2 (CCL2). CCL2 acted via its receptor C-C chemokine receptor 2 (CCR2) to enhance macrophage cell migration in vitro. The M2 macrophages in turn promoted glioblastoma cell proliferation and migration. The orthotopic mouse model showed that GBP1 recruited M2 macrophages into tumor to promote glioblastoma progression, and targeting CCL2/CCR2 signaling axis with a small molecule inhibitor RS504393 led to decreased macrophage attraction and M2 polarization and a significant tumor growth retardation and prolonged survival of tumor-bearing mice. Clinically, GBP1 expression positively correlated with M2 macrophage numbers and CCL2 expression in glioblastoma. Taken together, our results reveal that GBP1 modulates the tumor immune microenvironment through CCL2 induction to promote glioblastoma infiltrating growth, and targeting tumor-associated macrophages may represent a new therapeutic strategy against glioblastoma.
TMIC-53. IMPACT OF HFE EXPRESSION AND SEX ON THE TUMOR IMMUNE MICROENVIRONMENT IN GLIOBLASTOMA
Authors: Nesterova Darya , Lee Sang , Zacharia Brad , Lathia Justin , Rubin Joshua , Berens Michael , Barnholtz-Sloan Jill , Connor James 
Published: November 2019

Abstract
Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. Despite aggressive treatment, the median survival for patients with GBM remains approximately 1 year. Recent evidence demonstrates GBM is a sexually dimorphic disease, and that females have greater overall survival. We previously showed expression levels of HFE, an iron-regulating gene, significantly impacts survival in GBM. Moreover, this effect is sex-specific: females with low HFE expressing tumors have significantly longer survival than males with similar HFE expression. Moreover, HFE expression and survival appeared to correlate with markers of immune activity within the tumors. To further explore the impact of HFE expression on the immune infiltration of GBM, we utilized available TCGA GBM data for analysis by EstimateMe and DeconvuluteMe. These platforms utilize expression data to estimate the magnitude and cellular composition of immune cell infiltrates in tumors, respectively. We sought to correlate these computational measures with HFE expression levels and survival. We confirmed that immune and stromal cell infiltration of tumors is negatively correlated to survival. Consistent with our findings that high HFE levels have a negative impact on survival, high HFE expressing tumors possessed higher levels of both immune and stromal cell infiltration. Additionally, sex of the patient, but not MGMT methylation status, was significantly correlated with immune and stromal infiltration, with males displaying higher levels of infiltration. High HFE tumors were composed of greater numbers of all immune cell types than low HFE tumors. In both HFE groups, monocytes and macrophages comprised the greatest fraction of cells. At low HFE and positive MGMT methylation (where we previously noted the greatest survival differences), we find females have lower monocyte and M2 macrophage markers compared to males with similar features. Collectively, these data suggest that an HFE-immune cell infiltrate axis contributes to sex differences in GBM survival.
TMOD-03. SOMATIC MUTATIONS OF CHROMATIN REGULATOR Kmt2d IN CEREBELLAR PRECURSORS INFLUENCES SHH-MEDULLOBLASTOMA TUMORIGENESIS
Authors: Sanghrajka Reeti , Tan I-li , Wojcinski Alexandre , Rallapalli Harikrishna , Turnbull Daniel , Ge Kai , Joyner Alexandra 
Published: November 2019

Abstract
Medulloblastoma (MB), the most common malignant pediatric brain tumor, is a classic example of dysregulation of developmental pathways leading to tumorogenesis. Despite advancements in multi-modal therapies, most patients suffer from long-term neurocognitive and neuroendocrine disabilities. The Sonic Hedgehog subgroup of MB (SHH-MB) accounts for ~30% of all cases and originates from ATOH1+ cerebellar granule cell precursors (GCPs). Experimental data in mice has shown that activating mutations in the SHH pathway induce tumors only in rare GCPs, suggesting that additional mutations and epigenetic changes are required to influence tumor progression. The KMT2D gene, encoding the histone-lysine N-methyltransferase 2D, is amongst the ten most frequently mutated genes in MB, with somatic mutations seen in ~15% of all SHH-MB patients. We developed sporadic mouse models of SHH-MB with a low penetrance to enable studies of secondary mutations (Tan, PNAS, 2018). Immunofluorescence staining for KMT2D on early-stage SHH-MB lesions, mid-stage and late-stage tumors revealed that a subset of lesions/tumors (16/98) do not express KMT2D and are negative for H3K4me3. Interestingly, P53 and KMT2D expression showed a positive correlation in ~94% of tumors/lesions and NeuN and KMT2D showed a positive correlation in ~92% of tumors/lesions. In order to determine the roles for KMT2D in GCP proliferation and differentiation, and uncover whether and how KMT2D promotes SHH-MB tumorigenesis, we are using genetic mouse-models whereby Kmt2d is heterozygously or homozygously deleted alone, or in conjunction with activation of the SHH pathway. Mice with SHH-MB tumors expressing SmoM2 and a loss of Kmt2d develop aggressive tumors at high penetrance, with metastatic leptomeningeal spread in the brain stem and spinal cord. Thus, loss of Kmt2d increases SHH-MB tumor progression and leads to malignancy. Ongoing studies are determining how the chromatin landscape and gene expression are changed when Kmt2d is deleted in GCPs.
ACTR-70. A MULTISITE CLINICAL TRIAL OF SPECTROSCOPIC MRI-GUIDED RADIATION DOSE ESCALATION IN GLIOBLASTOMA PATIENTS
Authors: Mellon Eric , Gurbani Saumya , Ramesh Karthik , Weinberg Brent , Kleinberg Lawrence , Schreibmann Eduard , Barker Peter , Maudsley Andrew , Shim Hyunsuk , Shu Hui-Kuo 
Published: November 2019

Abstract
The standard of care for glioblastoma is neurosurgical resection followed by radiation therapy (RT) and temozolomide (TMZ) chemotherapy. Although RT is effective for glioblastoma, attempts to improve survival using RT dose escalation above 60 Gy have been largely unsuccessful. This may be because prior attempts have been targeted to resection cavity or enhancing tumor, which may not accurately predict areas at highest recurrence risk. To overcome the limitations of standard T1 and T2-weighted MRI in predicting tumor recurrence, we have shown that supplementation with 3D high-resolution spectroscopic MRI (sMRI) identifies actively proliferating tumor beyond areas of T1-enhancement by measuring endogenous metabolites and their ratios. Previously, we demonstrated that the choline to N-acetylaspartate ratio (Cho/NAA) best correlates with tumor cellularity in surgically resected tissue (ρ=0.82, p< 0.001) and, most importantly, areas of sMRI metabolic abnormalities predate disease recurrence in those same areas (Cordova et al, Neuro-Oncology 2016). Therefore, we seek to identify whether sMRI can be used by radiation oncologists to choose the optimal regions to target for RT dose escalation. To assess its feasibility and safety, we developed a web-based imaging platform designed specifically to incorporate sMRI into the RT planning clinical workflow and are using it in a multisite sMRI-guided dose escalation trial (NCT03137888; Emory, Johns Hopkins, U. Miami). Recently, we have completed full enrollment including 30 patients treated with sMRI-guided dose escalated RT across three institutions. We have demonstrated successful integration of sMRI into the RT planning workflow, and we have delivered sMRI-guided dose escalated RT plans to glioblastoma patients without severe adverse events to date. Follow-up data will be analyzed for overall and progression-free survival. Based on the feasibility and safety of this technique in the current trial, we plan to assess the efficacy of sMRI-guided dose-escalated RT on patient outcomes in a NCTN clinical trial.
TMOD-11. CHARACTERISATION OF THE POST-SURGICAL INVASIVE TUMOUR NICHE USING ASTROCYTE-GLIOBLASTOMA ORGANOIDS AND DECELLULARISED HUMAN BRAIN
Authors: Diksin Mohammed , Rowlinson Jonathan , Kondrashov Alexander , Denning Chris , Hughes Jaime , Constantin-Teodosiu Tim , Cui Wei , Scurr David , Ahmad Omar , Gell Christopher , Onion David , Croxall Nicola , Smith Stuart , Rahman Ruman 
Published: November 2019

Abstract
Glioblastoma therapeutic challenges are in considerable part due to myriad survival mechanisms which allow malignant cells to repurpose signalling pathways within discreet microenvironments. These Darwinian adaptations facilitate invasion into brain parenchyma and perivascular space. We hypothesised that pre-clinical modelling of glioma invasion by recapitulating early events occurring immediately after surgery at the glioblastoma invasive margin, could reveal the cross-talk between malignant cells and surrounding healthy astrocytes. We first generated transgenic H1-derived neural stem cells using CRISPR/Cas9-mediated knock-in of the YFP reporter gene under the control of the GFAP promoter at the AAVS1 safe harbour locus. Reproducible ultrahigh-throughput AggreWells™ (7200 mini-wells per plate) were used to create astrocyte-glioblastoma organoids, which we term ‘Gliomasphere Matrices’. YFP-labelled astrocytes were co-cultured with 10 treatment-naïve patient-derived cell lines isolated from the 5-aminolevulinic (5ALA)-determined glioblastoma invasive margin. Co-cultures were seeded upon a sequentially constructed, time-of-flight secondary ion mass spectrometry (ToF-SIMS)-characterised decellularised human brain extract. YFP-astrocytes were purified from each of the 10 Gliomasphere Matrices using fluorescence-activated cell sorting (FACS) after 6- and 10-days co-culture. RNA-sequencing of the putatively reprogrammed YFP-astrocytes showed the characteristic expression of canonical key regulators of multiple malignant diseases including high-grade glioma such as SND1 and EFNB2 in addition to the identification of a single novel marker located at chromosome 1 (C1orf61), highly expressed in malignant glioma when compared to somatic cancers according to TCGA RNA-sequencing data. Differentiated YFP-astrocytes also overexpressed IFITM2 and IFITM10, known to be involved in priming resistance against pathogenic microorganisms. This ultimately suggests a fluctuating state between malignant transformation imposed by the highly infiltrative glioma cells and the counter-action of the normal astrocytes to these deleterious invasive cells. This multi-faceted model offers a unique opportunity to recapitulate early molecular cross-talk which facilitates glioblastoma recurrence and may be utilised for high-throughput drug screening.