bluuebunny/crossref_metadata_2025_split huggingface dataset:
SURG-12. “NANOPASTE” THERAPY AS POTENTIAL TREATMENT OPTION FOR RECURRENT GLIOBLASTOMA
Authors: Schwake Michael , Grauer Oliver , Holling Markus , Brokinkel Benjamin , Müther Michael , Bruns Ann-Katrin , Wölfer Johannes , Stummer Walter 
Published: November 2019

Abstract

BACKGROUND
We recently showed that intracavitary thermotherapy with superparamagnetic iron-oxide nanoparticles can induce persistent inflammatory reactions which might lead to long-term stabilization in recurrent glioblastoma (GBM) patients.

METHODS
Here, we report further data from a series of ten recurrent GBM WHO IV patients (IDH WT, MGMT: methylated 30%, unmethylated 70%; median age: 59 years) who were treated with intracavitary thermotherapy after coating the resection cavity wall (“NanoPaste”) with NanoTherm® particles (MagForce AG, Berlin, Germany). All patients underwent six one-hour semi-weekly hyperthermia sessions in an alternating magnetic field (mean maximum temperature 52.3° C, SD +/- 6.0 °C). Six patients received concurrent radiotherapy at a dose of 39.6 Gy (5 x 1.8 Gy/week).

RESULTS
No major side effects were observed during active treatment. However, all patients developed cerebral edema and increasing clinical symptoms during treatment follow-up (median 92 days, range 73 to 144). Patients were treated with dexamethasone and, if necessary, underwent re-operation to remove nanoparticles (n=5). Histopathology revealed sustained necrosis and large amounts of nanoparticles without evidence for tumor activity as well as a prominent inflammatory reaction characterized by increased T-cell and myeloid cell infiltration. Median overall survival (mOS) for the study population was 10.1 months (CI 95% 8.0–12.2). A survival benefit was observed for patients treated at first recurrence (n=5) when compared to patients treated at second recurrence or later (mOS = 20.6 vs 9.4 months). Patients who received thermotherapy and concurrent radiotherapy (n=6) showed longer mOS than patients treated with thermotherapy alone (17.3 vs 8.6 months). Two patients had long-lasting treatment responses > 23 months with one patient still alive at 3.5 years after treatment without receiving any further therapy.

CONCLUSION
Our results warrant further investigations. A European clinical registry will be rolled out to further evaluate the potential of “NanoPaste” therapy for patients with recurrent glioblastoma.
SURG-22. CUSHING’S DISEASE: A DIFFICULT TO TREAT NEURO-ONCOLOGICAL CONDITION
Authors: Bora Santanu , Suri Ashish 
Published: November 2019

Abstract

BACKGROUND
Cushing disease (CD) comprises a spectrum of clinical manifestations secondary to hypercortisolism due to ACTH-secreting pituitary adenoma. Transsphenoidal adenomectomy remains the standard treatment. Because of the significant rate of recurrence or persistence of CD, it is of interest to determine factors that may correlate with long-term outcomes following surgical intervention.

OBJECTIVE
The objective of our study is to determine the remission rate after surgery with special emphasis on factors affecting remission.

METHODS
Data of all patients undergoing surgery for CD from 2009 to 2017 was analyzed retrospectively. Transphenoidal resection was the preferred treatment with a recent trend in favor of endonasal endoscopic skull base approach. Post-operative cortisol level of < 2 μg/dL was taken as remission and value between 2 and 5 μg/dL as possible remission.

RESULTS
104 patients operated primarily for CD were included for analysis. 47 patients underwent microscopic surgery, 55 endoscopic surgery and two were operated trans-cranially. Remission was achieved in 76.47% of patients. In univariate analysis, factors significantly associated with remission were (1) type of surgery (p=0.01); endoscopy (88.23% remission) better than microscopy (56.6% remission) (2) postoperative day-1 morning cortisol (p=0.004) and; (3) postoperative day-1 morning ACTH (p=0.015). In multivariate analysis, however only postoperative day-1 cortisol was found to be significant as predictor of remission (p=0.02).

CONCLUSION
Postoperative plasma cortisol level is a strong independent predictor of remission and value less than 10.7µgm/dl can be taken as cut off for predicting remission. Remission provided by endoscopy appears to be significantly better than microscopic approach.
TMIC-06. MYELOID POPULATIONS AND THE EFFECT OF NEOADJUVANT PD-1 INHIBITION IN THE GLIOBLASTOMA MICROENVIRONMENT: A SURFACEOMIC AND TRANSCRIPTOMIC DISSECTION AT THE SINGLE-CELL LEVEL
Authors: Mochizuki Aaron , Lee Alexander , Orpilla Joey , Kienzler Jenny , Galvez Mildred , Chow Frances , Davidson Tom , Wang Anthony , Everson Richard , Liau Linda , Cloughesy Timothy , Prins Robert 
Published: November 2019

Abstract

INTRODUCTION
Glioblastoma (GBM) is the most common malignant brain tumor in adults and is associated with a dismal prognosis. Neoadjuvant anti-PD-1 blockade has demonstrated efficacy in melanoma, non-small cell lung cancer and recurrent GBM; however, responses vary. While T cells have garnered considerable attention in the context of immunotherapy, the role of myeloid cells in the GBM microenvironment remains controversial.

METHODS
We isolated CD45+ immune populations from patients who underwent brain tumor resection at UCLA. We hypothesized that myeloid cells in glioblastoma contribute to T cell dysfunction; however, this immune suppression can be mitigated by neoadjuvant PD-1 inhibition. To test this, we utilized mass cytometry and single-cell RNA sequencing to characterize these immune populations.

RESULTS
Mass cytometry profiling of tumor infiltrating lymphocytes from patients with GBM demonstrated a preponderance of CD11b+ myeloid populations (75% versus 25% CD3+). At the transcriptomic level, myeloid cells in newly diagnosed GBMs exhibited decreased expression of CCL4 (loge fold change -1.18, Bonferroni-adjusted P = 1.62x10-254) and its ligands compared to anaplastic astrocytoma. In ranked gene set enrichment analysis, patients who received neoadjuvant pembrolizumab demonstrated enrichment in TNFα-, NFκB- and lipid metabolism-related gene sets by bootstrapped Kolmogorov-Smirnov test (Benjamini-Hochberg adjusted P = 4.74x10-3, 1.45x10-2 and 2.48x10-3, respectively) in tumor-associated myeloid populations. Additionally, single-cell trajectory analysis demonstrated increased CCL4 and decreased ISG15 with neoadjuvant checkpoint inhibition.

CONCLUSIONS
Here, we utilize mass cytometry and single-cell RNA sequencing to demonstrate the predominance and transcriptomic features of myeloid populations in GBM. Myeloid cells in patients who receive neoadjuvant PD-1 blockade re-express increased levels NFκB, TNFα and CCL4, a cytokine crucial for the recruitment of dendritic cells to the tumor for antigen-specific T cell activation. By delving into the GBM microenvironment at the single-cell level, we hope to better delineate the role of myeloid populations in this uniformly fatal tumor.
TMIC-08. IDENTIFICATION OF TUMOR SPECIFIC LYMPHOCYTES IN A MURINE GLIOMA MODEL
Authors: Shin David , Lamba Nikhil , Flores Catherine , Divita Bayli , Wildes Tyler , Grippin Adam , Fernandez Brandon , Dyson Kyle , Mitchell Duane 
Published: November 2019

Abstract

INTRODUCTION
One major challenge in the use of immunotherapy for glioblastoma is the identification of tumor specific lymphocytes within the tumor microenvironment. Previous studies in non-glioma cancer models have identified CD39 and PD1 as lymphocyte markers of tumor specificity. In this study, we demonstrate the existence of this specific T cell phenotype and show correlation with anti-tumor activity.

METHODS
We implanted KR158B murine glioma cells into right caudate nucleus into yellow fluorescent protein (YFP) interferon-gamma reporter mice for a total of 104 cells using stereotaxis. At 4 weeks, mice were sacrificed followed by organ harvest. Samples taken included tumor, cervical draining lymph nodes, spleen, and peripheral blood. These were processed into single cell suspensions and then stained for CD3, CD8, CD39, and PD1. Flow cytometry was performed on a BD FACSCanto II. Gating analysis was performed with FlowJo while data analysis was performed with GraphPad Prism.

RESULTS
Gating for CD3+ CD8+ on tumor lymphocytes reveals a significant population of CD39 and PD1 double positive (DP) cells (61.4%) not found in the peripheral organs (< 1.0%). Evaluation of these cells for YFP expression demonstrated significantly greater median fluorescence intensity (MFI) in the DP group as opposed to either of the single positive (SP) or double negative (DN) groups (DP = 225.4, SP-CD39 = 40.54, SP-PD1 = 82.7, DN = 29.5, p < 0.0001).

CONCLUSION
Here we demonstrate the existence of a unique phenotype of CD39+ and PD1+ expression on lymphocytes within the tumor microenvironment. These DP cells also had high levels of interferon gamma production compared SP and DN groups. This phenotype is not observed in peripheral circulating lymphocytes. Enrichment for this subpopulation will allow for delivery of purified lymphocyte-based immunotherapy in this murine glioma model.
TMIC-13. FEELING THE FORCE: DIFFERENCES IN THE MECHANOREGULATED MIGRATION OF HIGH GRADE GLIOMA BETWEEN INDIVIDUAL CELLS AND THOSE IN CONTACT WITH OTHER TUMOUR CELLS
Authors: Jegathees Thuvarahan , Prior Victoria , O’Neill Geraldine 
Published: November 2019

Abstract
A major limitation in the treatment of High Grade Gliomas (HGG) is their highly disseminating nature. While it is increasingly appreciated that the mechanical properties of the extracellular matrix, (measured as tissue elasticity, Young’s modulus, E), can independently cue cancer cell migration and invasion, to date there has been little consideration of this mechanism in HGG invasion. This is particularly important given that the brain parenchyma is a mechanically soft tissue (E values varying between 1 - 10 kPa). By measuring single cell migration we have previously demonstrated that molecular subclasses of HGGs exhibit different rigidity-sensitive and -insensitive migration. Following these findings, the present project aimed to determine whether these mechanosensitive phenotypes are maintained in the dissemination of multicellular tumour spheroids (MCTSs) that represent in vivo organisation of the primary tumour bulk. Therefore MCTSs composed of primary patient-derived HGG cells with pre-established single cell mechanosensitive phenotypes were cultured on mechanically tuneable polyacrylamide hydrogels, mimicking the range of physiological tissue rigidities. Bright-field time-lapse images were then captured over a period of 48 hours, 6 images per hour. In order to quantitate the migratory behaviours, we adapted a previously published automated image analysis program to segment the MCTS images into proliferative and migratory regions. Our analysis suggests that the cellular mechano-phenotype is affected by contact with neighbouring cells, as the migratory response to tissue stiffness is quantitatively different in the MCTSs. Our results highlight different migratory behaviour between HGG cells within the primary tumour mass versus individual cells that escape. Our results reveal the complex migratory behaviour of HGG cells and suggests that successful anti-invasive therapies will need different strategies depending on tumour cell location.
TMIC-14. PD-L1 EXPRESSION IS NEGATIVELY CORRELATED TO OUTCOMES IN PATIENTS WITH MGMT METHYLATED PROMOTERS IN GBM
Authors: Srivastava Siddhartha , Choi John , Lim Michael 
Published: November 2019

Abstract

BACKGROUND
Glioblastoma is a high-grade glioma and is considered the most aggressive primary brain tumor with a median overall survival of 11–15 months. Methylation of the promoter of the MGMT gene, which encodes a DNA repair protein, has been shown to be a good prognostic indicator for GBM survival. It is known that GBM has elevated expression of several immune checkpoint molecules that allow the tumor to evade anti-tumor immune response. Therefore, it is important to elucidate connections between prognostic factors like methylation status and immunologic markers in the tumor microenvironment (TME) that might lead to immunosuppression.

METHODS
Patients with resected GBM tumor samples were identified by pathology reports as having tumors with either methylated or unmethylated MGMT promoters. Corresponding patient tumor biopsy samples were embedded in paraffin, sectioned, and then stained using specific antibodies for known immune checkpoint molecules: PD-1, PD-L1, LAG-3, TIM-3, CSF1R, and IDO-1.

RESULTS
In our cohort of 34 patients, 17 had methylated MGMT promoter regions and 17 did not. We found no statistically significant difference between methylated and unmethylated MGMT promoter status for immune checkpoint expression. However, we did find a statistically significant negative correlation (P< 0.05) between the degree of PD-L1 expression in the TME and the progression free survival of patients with the MGMT promoter methylation phenotype.

CONCLUSION
Our study examined the relationship between immune checkpoint markers and methylation status of MGMT promoters in GBM. While there was no statistically significant difference between these two groups within the immunological framework of this study, there was a statistically significant negative correlation showing that increased PD-L1 expression in patients with methylated MGMT promoter tumors correlated to a worse progression free survival. Future studies are indicated to investigate the correlation between PD-L1 expression in relation to GBM treatment prognosis and its dependence on MGMT promoter methylation.
TMIC-20. ELIMINATION OF SENESCENT ASTROCYTES IN THE BRAIN TUMOR MICROENVIRONMENT ATTENUATES GLIOBLASTOMA RECURRENCE AFTER RADIOTHERAPY
Authors: Fletcher-Sananikone Eliot , Mukherjee Bipasha , Burma Sandeep 
Published: November 2019

Abstract
Glioblastomas (GBM) are treated with high doses of ionizing radiation (IR) yet these tumors inevitably recur, and the recurrent tumors are highly therapy resistant. During GBM therapy, the surrounding brain tissue is irradiated along with the tumor. IR induces senescence in multiple cell types, and senescent stromal cells are known to promote the growth of neighboring tumor cells by secreting cytokines which create a senescence-associated secretory phenotype (SASP). We hypothesize that IR-induced senescence of normal brain cells in the tumor microenvironment is a powerful driver of GBM recurrence. We intra-cranially irradiated C57BL/6J mice, and found evidence of widespread senescence, with the astrocytic population being highly susceptible. Genomic analyses of irradiated brains revealed an altered transcriptomic profile which included upregulation of CDKN1A (p21), a key enforcer of senescence, and increased expression of SASP proteins including HGF, the ligand for the RTK Met. We orthotopically implanted mock-irradiated or irradiated mice with a limiting number of syngeneic glioma cells. Pre-irradiation of mouse brains resulted in a striking increase in tumor growth and invasion driven by Met activation in the tumor cells. Importantly, irradiated p21-/- mouse brains did not exhibit SASP and failed to promote tumor growth. Irradiated primary astrocytes underwent senescence in vitro and promoted the migration of glioma cells, and this could be attenuated with HGF-neutralizing antibodies or by the Met inhibitor Crizotinib. These findings indicate that SASP factors (like HGF) in the irradiated brain microenvironment could drive GBM recurrence after radiotherapy via the activation of RTKs (like MET) in the tumor cells. Significantly, we found that senolytic drugs can selectively kill senescent astrocytes both in vitro and in vivo resulting in attenuated growth of glioma cells. These results are of great translational significance as they indicate that adjuvant therapy with senolytic drugs might attenuate GBM recurrence after radiotherapy.
TMIC-25. MODIFICATION OF EXTRACELLULAR MATRIX ENHANCES ONCOLYTIC ADENOVIRUS IMMUNOTHERAPY IN GLIOBLASTOMA
Authors: Kiyokawa Juri , Kawamura Yoichiro , Martuza Robert , Rabkin Samuel , Shah Khalid , Wakimoto Hiroaki 
Published: November 2019

Abstract
Complex interplay between heterogeneous cells and extracellular matrix (ECM) in the tumor microenvironment drives the pathogenesis of glioblastoma (GBM). Glycosaminoglycan hyaluronic acid (HA) is a major component of GBM ECM, and is associated with tumor growth, invasion, and resistance to treatments. Delta24-RGD oncolytic adenovirus is a powerful cancer therapeutic and is currently under clinical evaluation for GBM. We hypothesized that degradation of HA would enhance oncolytic adenovirus immunotherapy of GBM by overcoming the immunosuppressive functions of GBM ECM. Intratumoral injections of ICOVIR17, a delta24-RGD oncolytic adenovirus carrying hyaluronidase PH20 cDNA, increased animal survival, in comparison to its parental virus ICOVIR15, in an orthotopic GBM model generated with murine 005 stem-like GBM cells in immunocompetent C57/Bl6 mice. ICOVIR17 promoted the degradation of HA, and induced an increase in tumor infiltrating CD8+ T cells and macrophages, compared with ICOVIR15. This led to the upregulation of immune checkpoint PD-L1 on GBM cells and macrophages, while it downregulated immune checkpoints TIM3 and CTLA-4 on CD8+ T cells. The combination therapy of ICOVIR17 and systemic administration of anti-PD-1 antibody significantly prolonged the survival of mice bearing intracerebral GBM compared to no treatment control group and monotherapy groups, and achieved long-term remission in 21% of treated animals. Flow cytometry analysis showed that the combination treatment significantly increased the ratio of effector/regulatory (CD8/Treg) T cells in the brain, compared with all the other three groups. Furthermore, antibody and clodronate-mediated in vivo depletion of immune subsets revealed that CD4+, CD8+ T cells and macrophages were all necessary for combination therapy to be effective as any of these depletions abrogated efficacy. Our findings reveal that ICOVIR17-mediated degradation of HA within GBM dramatically alters the immune landscape of the tumor microenvironment, and offer a mechanistically rationale combination immunotherapy with PD-L1/PD-1 blockade that results in superior anti-GBM efficacy.
TMIC-26. PRECLINICAL MODEL SYSTEMS OF GLIOBLASTOMA REVEAL MICROENVIRONMENTAL PROGRAMS AND DEPENDENCIES IN PATIENT TUMORS
Authors: Bayley Nicholas , Tse Christopher , Baufeld Lynn , Gosa Laura , Yan Weihong , Zhu Henan , Balanis Nikolas , Cloughesy Timothy , Liau Linda , Graeber Thomas , Nathanson David 
Published: November 2019

Abstract
Patient-derived model systems serve as a platform for translational research representing the heterogeneity of human cancers, and their success in recapitulating disease-driving genomic alterations is well-documented. While recent studies have demonstrated genomic and functional divergence in patient-derived models with passaging, the need for accurate preclinical models remains. Glioblastoma (GBM) is the most common and aggressive primary brain tumor, and thus far preclinical models have failed to consistently replicate the responses found in patients. We therefore aimed to evaluate the multi-omic fidelity of low-passage GBM model systems across in vitro and in vivo environments and to elucidate the molecular features in which they differ. To this end we established a biobank of glioma direct-from-patient orthotopic xenograft (GliomaPDOX) models and primary gliomasphere cultures (GSCs) and performed whole-exome and RNA sequencing of over 40 purified patient tumors and their matched GliomaPDOXs and GSCs to facilitate paired comparisons across a gradient of full tumor microenvironment (TME) presence. We observed global genomic and transcriptomic fidelity in both systems, but specific programmatic gene expression differences associated with cell-cell interactions in the brain TME, glial cell identity, and in vitro GSC-forming ability. GSCs and GSC-forming ability are strongly associated with an astrocytic gene expression signature, while more stem-like and oligodendrocytic patient tumors including IDH- and H3F3A-mutant GBMs more successfully engraft in GliomaPDOXs. This result implicates the brain TME as a support system for these more stem/oligo-like tumors. Transcription factor network analysis identified regulators of the NOTCH and MYC pathways as strongly enriched in this subgroup of patient tumors and their derivative xenografts, and provides potential targets for therapeutic intervention in near future experiments. Collectively, these findings underline the critical role of the TME in defining GBM cell state, reveal the heterogeneity of TME dependence across patient tumors, and link this dependency to therapeutically actionable molecular features.
TMIC-27. GLUTAMATERGIC NEURON-GLIOMA SYNAPSES DRIVE BRAIN TUMOUR PROGRESSION
Authors: Venkataramani Varun , Tanev Dimitar , Strahle Christopher , Studier-Fischer Alexander , Fankhauser Laura , Kessler Tobias , Losada Perez Maria , Körber Christoph , Kardorff Markus , Ratliff Miriam , Xie Ruifan , Horstmann Heinz , Messer Mirko , Paik Sang , Knabbe Johannes , Sahm Felix , Kurz Felix , Acikgoez Azer , Herrrmannsdörfer Frank , Agarwal Amit , Bergles Dwight , Chalmers Anthony , Miletic Hrvoje , Turcan Sevin , Mawrin Christian , Hänggi Daniel , Liu Hai-Kun , Casas Tinto Sergio , Wick Wolfgang , Winkler Frank , Kuner Thomas 
Published: November 2019

Abstract
A network of communicating tumour cells established by tumour microtubes (TMs) is supposed to mediate relevant aspects of progression and resistance of incurable gliomas. Moreover, neuronal activity has been shown to foster malignant behavior of glioma cells by non-synaptic paracrine and autocrine mechanisms. Here, we report an unexpected direct communication channel between neurons and glioma cells in multiple disease models as well as in astrocytomas and glioblastomas (GBs) of adult patients: functional bona fide chemical synapses formed between presynaptic neurons and postsynaptic glioma cells. These neurogliomal synapses (NGS) show a typical synaptic ultrastructure, are located on TM networks, and produce depolarizing postsynaptic currents mediated by glutamate receptors of the AMPA subtype. AMPA-type glutamate receptors (AMPAR) are expressed by a molecularly and morphologically distinct subpopulation of network-integrated glioma cells. Increased neuronal activity under epileptic conditions ex vivo or neuronal optogenetic stimulation in vivo enhanced, while general anesthesia diminished synchronized calcium transients in TM-connected glioma networks. Accordingly, anesthesia reduced invasiveness of TM-positive tumour cells in mice. Genetic perturbation of AMPAR or chronic AMPAR inhibition by perampanel decreased glioma invasion and proliferation in mice and deletion of GluRII in Drosophila glioma increased survival. These findings reveal a hitherto unappreciated direct synaptic communication between neurons and glioma cells that appears relevant for brain tumour biology, implying new avenues for glioma treatment.