bluuebunny/crossref_metadata_2025 huggingface dataset:
SURG-04. INTRAOPERATIVE HAND-HELD LINE-SCANNED DUAL-AXIS CONFOCAL MICROSCOPY FOR VISUALIZING LOW-GRADE GLIOMAS
Authors: Fujita Yoko , Wei Linpeng , Liu Jonathan T C , Sanai Nader
Published: November 2019

BACKGROUND

Extent of resection is a prognostic factor for low- and high-grade gliomas. Fluorescence guided surgery (FGS) using five-aminolevulinic acid (5-ALA) is associated with greater extent of resection in high-grade gliomas. However, for low-grade gliomas, intraoperative imaging technologies such as FGS, have not been optimized to distinguish tumor from normal tissue. Intraoperative confocal microscopy can better visualize tissue cytoarchitecture in real-time. Here we report on the feasibility of a newly-developed, hand-held, line-scanned dual-axis (LS-DAC) confocal microscope in distinguishing tumor vs. normal cells in ex vivo human low-grade glioma tissue.

METHOD

Ten low-grade glioma patients who underwent craniotomy were enrolled. Resected specimens were labelled with acridine orange (1mM) for one minute, and exposed surfaces were immediately imaged by our device. Subsequently, specimens were cut into sections and stained with H&E for histopathological analysis.

RESULTS

LS-DAC confocal microscope visualized nuclei of tumor cells vs. surrounding tissue, demonstrating clear differences in cellularity in the two compartments. Acquired images were comparable to those observed on matched H&E-stained sections. Live images provided minimal motion artifact due to the higher frame rate of 16 Hz.

CONCLUSION

LS-DAC confocal microscope provided real-time, high-contrast mosaic images of human low-grade glioma tissue ex vivo. The ability to distinguish tumor vs. normal tissue at the cellular level with little motion artifact, as well as the device’s hand-held design, suggests this technology merits additional investigation as an intraoperative adjunct for low-grade glioma surgery.
ACTR-59. A PHASE 1 STUDY OF BPM31510 PLUS VITAMIN K IN SUBJECTS WITH HIGH-GRADE GLIOMA THAT HAS RECURRED ON A BEVACIZUMAB-CONTAINING REGIMEN
Authors: Recht Lawrence , Thomas Reena , Bertrand Sophie , Yerballa Priya , Li Gordon , Iv Michael , Narain Niven , Sarangarajan Rangaprasad , Granger Elder , Nagpal Seema
Published: November 2019

BACKGROUND

High-grade gliomas (HGG) are characterized by dysregulated metabolism, utilizing glycolysis for energy production to support unrestricted growth. BPM 31510, an ubidecarenone (coenzyme Q10) containing lipid nanodispersion, causes a switch in cancer energy sourcing from glycolysis towards mitochondrial oxidative phosphorylation in vitro, reversing the Warburg effect and suggesting potential as an anti-tumor agent. The current study is a phase I study of BPM31510 + vitamin K in GB with tumor growth after bevacizumab (BEV).

METHODS

This is an open-label phase I study of BPM31510 continuous infusion with weekly vitamin K (10mg IM) in HGG patients using an mTPI design, starting at 110mg/kg, allowing for a single dose de-escalation and 2 dose-escalations. Patients had received first-line ChemoRadiation and were in recurrence following a BEV containing regimen.

RESULTS

9 eligible and evaluable patients completed the 28 day DLT period. 8 patients had primary GB, 1 had anaplastic astrocytoma with confirmed pathologic transformation to GB. Median age was 55 years (27–67) and median KPS 70 (60–90) at enrollment. 4 patients were treated at the highest dose 171mg/kg, where there was a single DLT: Grade 3 AST & ALT. The most common grade 1–2 AEs possibly, probably or definitely related to drug were elevated AST, rash, and fatigue, each occurring in 3 patients. Median OS for 9 eligible/evaluable patients was 128 days (95% CI: 48–209) while PFS was 34 days (CI of mean 8.9). 3 patients are currently alive; 2 patients have survived >1 year. PK/PD data are being processed and will be presented.

CONCLUSION

This study confirms that BPM 31510 + vitamin K is safe and feasible in treatment-refractory HGG patients. Though this study demonstrates safety at 171mg/kg, the proposed dose for future studies in GB, based on additional pre-clinical and non-GB clinical data is 88mg/kg.
SURG-19. REORGANIZATION OF LANGUAGE ENABLES SAFE RESECTION OF TUMORS IN AND AROUND BROCA’S AREA
Authors: Holmes Emma , Kerr Keith , Kadipasaoglu Cihan , Tandon Nitin
Published: November 2019

INTRODUCTION

Since its discovery in the 1800s, Broca’s area has been viewed as a critical node for language production. Previously, pathologies in this area have been considered unresectable due to concern for producing iatrogenic language production deficits. Emerging literature suggests that although acute lesions in this area can cause widespread deficits, slow growing lesions are less correlated with these deficits due to cortical language reorganization. Based on this data, we managed a cohort with Broca’s area lesions with surgical resection using awake intra-operative language mapping.

METHODS

All 150 awake craniotomies performed by the senior author over a twelve-year period (2006–2017) at a single institution were reviewed. For each patient the imaging was carefully evaluated to localize the neoplasm relative to pars triangularis or pars opercularis in the language dominant hemisphere. Language dominance was confirmed using WADA testing or fMRI. All patients underwent cortical language mapping using a battery of tasks coupled with cortical stimulation.

RESULTS

A total of 31 surgeries in 29 patients (65.5% male, 86.2% righthanded) were identified. The average age was 41. Patients presented with seizures (64.5%), speech difficulties (35.5%) or headaches (19.4%). A gross or near total resection was achieved in 26/29 (89.7%) of patients. Pathological evaluation revealed grade 2 gliomas (8), grade 3 gliomas (13) and glioblastoma (9). Post-operatively, 8 (25.8%) patients had new or worsening speech deficits, all of which resolved to baseline at follow-up.

CONCLUSION

Broca’s area lesions can be safely resected in patients using an awake craniotomy technique with language mapping. In our series, the majority of patients had gross or near total resections, few patients had new deficits, and none had permanent new deficits. Considering the increasing evidence in favor of cytoreduction to manage glial neoplasms, this technique should be employed routinely for pathologies in this area to optimize patient outcomes.
SURG-21. STEREOTACTIC BIOPSY FOR DEEP SEATED BRAIN LESIONS USING THE LEKSELL STEREOTACTIC FRAME SYSTEM
Authors: Fujimaki Takamitsu , Hirata Sachiko , Terano Naruhiko , Wakiya Kenji , Adachi Jun-ichi , Nishikawa Ryo , Sasaki Atsushi , Kobayashi Masahito
Published: November 2019

PURPOSE

To evaluate the results of stereotactic biopsies.

PATIENTS AND METHODS

Fifty-two patients with intraaxial lesions suspected of brain tumor. The locations of lesions includes, 19 deep cerebral white matter, 9 basal ganglia, 10 thalamus, 4 midbrain and 6 pons. Patients age ranged from 9 to 86 years (median 65 years), 33 were men and 19 were women. Under local anesthesia the Leksell stereotactic frame was fixed and the MRI were taken. Neuroimages such as enhanced CT scan or PET study were also used as references. After MRI patients were transferred to OR and under general anesthesia, several samples were taken with 2.1mm diameter needle by aspiration. Most of the cases the biopsy was done through frontal lobe, but in some cases through temporal lobe or through cerebellum. The samples were taken deeper and nearer regions of the designed targets with same trajectory, also. If there were cysts, aspiration of the cyst was performed as much as possible. The trajectory should avoid sulci, cortical veins or ventricular system. After biopsy inside the needle were irrigated repeatedly with 0.1 - 0.2 ml saline using thin plastic tube until the fluid does not contain bloody fluids to ensure hemostasis.

RESULTS

In all patients appropriate samples for pathological diagnosis were obtained. The diagnoses were 28 gliomas (pilocytic 1, grade II 8, grade III 11, grade VI (GBM) 6, high grade 1, glial tumor 1), 17 lymphomas, 3 germinoma and 2 were non-tumorous pathology. There were no symptomatic bleeding nor neurological complications.

CONCLUSION

With detailed planning, stereotactic biopsy was safely performed even from basal ganglia or brainstem. Trajectories other than from frontal can be also considered for some lesions. Repeated irrigation with saline might effective to prevent symptomatic bleeding and this case series shows lower complication rates compared to the published literatures.
SURG-23. INTRAPARENCHYMAL MUCOSA-ASSOCIATED LYMPHOID TISSUE (MALT) LYMPHOMA: A NOVEL DISEASE PRESENTATION
Authors: Fatehi Mostafa , Haw Charles
Published: November 2019

INTRODUCTION

Low grade B-cell lymphomas arising from the marginal zone of secondary lymphatic follicles constitute less than 10% of lymphomas. This condition was initially described in the stomach and the nasopharynx. However, there have been several reports of isolated dural-based intracranial lesions.

METHODS

A review of the literature using the EMBASE and MEDLINE databases yielded 12 previous cases of dural MALT lymphomas but none that were entirely intra-parenchymal.

RESULTS

Here, we present the case of a 67 year male who was found to have a convexity meningioma; and another, intra-parenchymal, lesion with radiologic features consistent with a low grade glial tumor. Upon resection of both lesions, the intra-axial tumor was found to be a mucosa-associated lymphoid tissue lymphoma. He has subsequently been referred for initiation of needing adjuvant therapies.

CONCLUSIONS

In addition to posing challenges for radiologic diagnosis, this case presents questions regarding the oncologic management of MALT lesions in the brain.
SURG-24. A RISK SCORE FOR PREDICTING DEVELOPMENT OF DIABETES INSIPIDUS AFTER PITUITARY ADENOMA RESECTION
Authors: Jackson Christina , Vo Chau , Daniels Marcus , Chaichana Kaisorn
Published: November 2019

INTRODUCTION

The development of diabetes insipidus (DI) after pituitary adenoma resection is associated with worse post-surgical morbidity and longer hospital stay. Identification of clinical predictors of development of DI would allow for appropriate stratification of patients to optimize preoperative counseling and postoperative management.

METHODS

We conducted a retrospective review of 349 patients who underwent pituitary adenoma resection at Johns Hopkins Hospital between 2003 and 2017. We used unadjusted and adjusted logistic regression to identify predictors of developing DI. Factors which were associated with DI development (p< 0.1), were included in our multivariable model. Factors which remained associated with DI development were then used to develop a DI risk score. RESULT: 67 (19.2%) patients developed post-surgical DI. Patients who had symptoms of prolactinoma, surgery through one nare, or were on steroid treatment were more likely to develop DI. Conversely, patients who had unilateral cavernous sinus invasion were less likely to develop DI. We used these predictors to generate the DI risk score. Patients were assigned 1 point for each risk factor (symptoms of prolactinoma, steroids, or surgery through one nare) for developing DI, but 1 point was subtracted if they had a protective factor (unilateral cavernous sinus invasion). Patients with 0 points had a 10.7% probability of developing DI, patients with 1 point had a 18.5% probability of developing DI, patients with 2 points had a 41.2% probability of developing DI, and patients with 3 points had a 44.4% probability of DI.

CONCLUSIONS

We identified several predictors of DI development after pituitary adenoma resection, and used these to generate a DI risk score. The DI risk score could help stratify patients’ likelihood of postsurgical DI development, although validation through larger prospective multi-center studies are needed.
SURG-30. CLINICAL COURSE OF IDH-MUTATED LOW-GRADE GLIOMAS DURING THE POSTSURGICAL ACTIVE MONITORING PHASE: ASYMPTOMATIC PATIENTS, WELL CONTROLLED SEIZURES, BUT CONTINUOUS GROWTH OF TUMOR RESIDUES
Authors: Wijnenga Maarten , Daftari Besheli Matin , French Pim , Dubbink Hendrikus , Smits Marion , Kros Johan , Bromberg Jacoline E C , Taal Walter , Dirven Clemens , Vincent Arnaud , van den Bent Martin
Published: November 2019

INTRODUCTION

Postponing adjuvant treatment after resection in IDH-mutated low-grade glioma (LGG) seems appropriate in selected patients. Here we describe the clinical course of these patients during post-resection active monitoring with MRI scans, as literature on this topic is scarce.

METHODS

We included IDH-mutated LGG patients that underwent surgery between 2003–2016, with clinical follow-up including MR scans available. Samples were classified according to the 2016 WHO classification. We collected baseline clinical information, estimates of seizure control during follow-up, longitudinal evolution of post-resection LGG volumes when adjuvant therapy was postponed, and the clinicians’ reasons to either start immediate adjuvant treatment or postpone treatment, and reasons to initiate adjuvant treatment in later stage. We compared patients that underwent immediate postsurgical adjuvant treatment with patients that underwent active MRI monitoring until further progression.

RESULTS AND CONCLUSIONS

197 patients were included, of which 108 were IDH-mutated astrocytomas, and 89 were oligodendrogliomas. Of these, 97 patients were actively followed with MRI scans, and 100 patients underwent immediate adjuvant therapy after initial surgery. Patients that received immediate adjuvant therapy were older and had less extensive resections than patients wherein adjuvant treatment was postponed (median age 45 years vs. 37 years, P< 0.001; median postoperative tumor volume 31cm3 vs 2.68cm3, P< 0.001). The duration of the active surveillance period in the patients wherein adjuvant treatment was postponed correlated with the extent of resection, with shorter time until adjuvant treatment in case of larger postoperative tumor volumes. All LGG lesions showed continuous growth during the active surveillance period, with median growth rates of 3mm/year for oligodendrogliomas and 4mm/year in IDH- mutated astrocytomas (P = 0.0093). Seizures were well controlled, with the majority of patients using only one anti-epileptic drug. The majority of patients stayed asymptomatic during follow-up, and the reason to initiate further adjuvant treatment was always radiological growth.
TMIC-05. GLIOBLASTOMA CONTAINS TOPOLOGICALLY DISTINCT PROLIFERATIVE AND METABOLICALLY DEFINED SUBPOPULATIONS OF NESTIN AND GLUT1-POSITIVE CELLS
Authors: Prosniak Michael , Kenyon Lawrence , Craig Hooper D , Andrews David
Published: November 2019

Glioblastoma (GBM), the most aggressive primary brain malignancy, consists of diverse cell subpopulations expressing a variety of cell lineage markers. Improvements in GBM therapy and survival require a deeper knowledge of the shifting subpopulations of tumorigenic cells within typical GBMs and their relative vulnerabilities. GBM development is associated with the appearance of highly proliferative tumor cells that lead to a hypoxic, metabolically reprogrammed, immunosuppressive microenvironment that favors tumor progression. In addition, GBM contains self-renewing, tumorigenic cancer stem cells (CSC) that contribute to tumor initiation and therapeutic resistance. Using a combined multicolor immunofluorescent and Hematoxylin and Eosin (H&E) staining approach with archival formalin-fixed, paraffin embedded tissue from primary, recurrent, and autopsy glioblastoma specimens, we have investigated the complex topology of the GBM microenvironment with particular focus on the association and distribution of several important functional and metabolic markers. High-resolution tissue image analysis permitted precise colocalization and quantification of four biomarkers (Ki-67, GLUT1, Nestin, Hif-1a) of the entire specimen image and at the single cell level. Our results demonstrate discrete subpopulations with specific regional localization with respect to blood vessels and to each other. In particular, highly proliferative Nestin-positive cells are preferentially located near blood vessels. These cells do not express GLUT1 and are Hif-1a positive. In contrast, GLUT1-positive cells are negative for Nestin, demonstrate low proliferation, and are preferentially located at the zones of pseudopalisading necrosis, furthest from blood vessels. In addition, GLUT1-positive cells show reduced Hif-1a expression compared to Nestin-positive cells. Our novel approach provides a means to identify, characterize, and monitor the changing nature of GBM before and after various treatment modalities with the ultimate aim of revealing selective vulnerabilities in order to retard or cure this neoplasm.
ACTR-62. PHASE I TRIAL OF TG02 PLUS DOSE-DENSE OR METRONOMIC TEMOZOLOMIDE FOR RECURRENT HIGH-GRADE ASTROCYTOMA IN ADULTS
Authors: Wu Jing , Bryla Christine , Su Yu-Ting , Grajkowska Ewa , McCoy Ann , Boris Lisa , Antony Ramya , Garren Nancy , Siegel Christine , Cordova Christine , Aboud Orwa , Vera Elizabeth , Lawhon Tracy , Penas-Prado Marta , Theeler Brett , Mendoza Tito , Armstrong Terri , Yuan Ying , Gilbert Mark
Published: November 2019

BACKGROUND

Therapies targeting multiple survival pathways are desirable for high-grade gliomas. TG02 (Zotiraciclib), a CDK9 inhibitor, regulates transcription and metabolism of tumor cells and synergizes with temozolomide. A phase I/II trial was launched to test the TG02/temozolomide combined treatment in recurrent high-grade astrocytomas. Phase I results are reported here.

METHODS

Adults with recurrent high-grade astrocytoma, KPS≥60, adequate organ function, < 2 prior relapses were enrolled. Primary endpoint was dose limiting toxicity (DLT) in cycle1 in each arm. Bayesian optimal interval design was employed to determine the maximum tolerated dose (MTD) with the target DLT rate of 35% and the toxicity profile of the combination of TG02 (starting dose 200mg orally on days1,12,15, and 26) and temozolomide, either as a dose-dense (DD; 125mg/m2/d, 7on/7off, Arm1) or metronomic (MN; 50mg/m2/d, Arm2) dosing schedule on a 28-day cycle.

RESULTS

Thirty-eight patients were evaluable; median age 50.7, KPS 90. Of 18 evaluable patients in Arm1, at TG02 dose-level 200mg, 1/6 had a DLT: Gr3 diarrhea; at dose-level 250mg, 3/12 had DLTs: Gr4 neutropenia for over 5 days, Gr3 elevated ALT, and Gr3 fatigue. Of 20 evaluable patients in Arm2, at TG02 dose-level 200mg, 1/6 had a DLT: recurrent Gr3 neutropenia; at dose-level 250mg, 5/12 had a DLT: Gr3 elevated ALT, Gr3 fatigue, and Gr4 neutropenia; at dose-level 300mg,1 of 2 had a DLT: Gr4 febrile neutropenia, Gr4 elevated ALT, Gr4 elevated AST. TG02 dose-level of 250mg was declared as the MTD in both Arms. Using the MDASI-BT, patients with high symptom burden had increased symptoms during cycle1 but became stable as they continued treatment.

CONCLUSION

The combination of TG02 at the MTD of 250mg with DD or MN temozolomide was tolerated. Cohort expansion continues at the MTD in both arms. Objective responses have been observed, suggesting activity of this regimen and supporting continued investigation.
TMIC-17. ASTROCYTE SENESCENCE CONTRIBUTES TO SEX DIFFERENCES IN THE AGE-RELATED INCREASE IN GLIOBLASTOMA INCIDENCE
Authors: Broestl Lauren , Sponagel Jasmin , Rhee Gina , Grandison Lucia , Kfoury Najla , Rockwell Nathan , Hill Cameron , Rubin Joshua
Published: November 2019

Incidence rates for glioblastoma increase exponentially with age in a sex-specific manner, with a steeper increase observed in men. This suggests that age may be a more significant factor in promoting male tumors than female tumors. Drivers in the age-related cancer increase include both the accumulation of DNA damage and microenvironment changes, specifically an increase in the number of senescent cells. Cellular senescence comprises two distinct components – a cell cycle arrest program that prevents proliferation of mutated cells and acts as a potent anti-cancer mechanism, and a paracrine signaling component that can have both pro- and anti-tumorigenic properties. The contribution of senescence to brain tumor incidence and outcome is currently unknown; additionally, no research has been done on whether there are sex differences in mechanisms of senescence induction or in the secretory phenotype of senescent cells. Using both wildtype astrocytes and a glioblastoma model, we show that female cells have a lower threshold for senescence induction in response to oxidative stress, telomere shortening, and DNA damage, and that sex differences in senescence induction in response to DNA damage are in part mediated by differences in the regulation of p21. In addition, we show that male and female senescent astrocytes differ in their secretory phenotypes. Male senescent astrocytes secrete more tumor promoting factors, and conditioned media from male but not female senescent astrocytes promotes tumor cell proliferation. These findings provide a potential explanation for sex differences in glioblastoma incidence rates. Achieving a better understanding of mechanisms of senescence and how they differ in male and female cells could advance development of senescence directed therapies and potentially improve cancer treatment for a range of tumor types.
TMIC-38. CLINICAL AND IMMUNOLOGICAL CHARACTERIZATION OF HERPES VIRUS ENTRY MEDIATOR IN HUMAN GLIOMAS
Authors: Han Ming-Zhi , Wang Shuai , Wang Dong-Hai
Published: November 2019

BACKGROUND

Dysregulation of immune checkpoint members within tumors, including glioblastoma (GBM), is related to immune evasion. Herpes virus entry mediator (HVEM) is a novel identified immune checkpoint molecule which plays essential roles in both innate and acquired immunity. Despite recent advances in exploring the function HVEM in a variety cancer types, the clinical and immunological importance of HVEM in human gliomas remain largely unknown.

METHODS

Molecular and clinical data was obtained from publicly genomic databases. Immunohistochemistry was applied to assess the protein level of HVEM. Matlab software as well as R language were used for statistical analysis.

RESULTS

HVEM was found to be elevated in aggressive gliomas, especially in isocitrate dehydrogenase (IDH) wild-type GBM. High expression of HVEM was associated with Mesenchymal subtype and showed promising prognostic values based on Cox regression model and nomogram model. HVEM showed intra-tumor heterogeneity with abundant in peri-necrotic zone and microvascular region. In addition, HVEM high patients were more frequent with genomic aberrations of oncogenic events. Gene ontology and pathway analysis uncovered the enrichment of HVEM in multiple immune regulation process, especially in the suppression of T cell mediated immunity in GBM. Moreover, HVEM was tightly associated with several infiltrating immune and stromal cell lineages in microenvironment, and showed high correlation with other immune checkpoints.

CONCLUSIONS

Our data highlights the importance of HVEM in GBM progression and that targeting HVEM combined with current immune checkpoint blockades might be a novel therapeutic strategy for GBM.
TMIC-62. FYN, AN EFFECTOR OF ONCOGENIC RECEPTOR TYROSINE KINASES SIGNALING IN GLIOBLASTOMA, INHIBITS ANTI-GLIOMA IMMUNE RESPONSES: IMPLICATIONS FOR IMMUNOTHERAPY
Authors: Comba Andrea , J Dunn Patrick , E Argento Anna , Kadiyala Padma , Ventosa Maria , Patel Priti , Zamler Daniel , Nunez Felipe , Zhao Lili , Castro Maria , Lowenstein Pedro
Published: November 2019

There is currently much excitement for the use of immunotherapies in cancer. In spite of positive results using checkpoint inhibitors in melanoma and CAR T cells in leukemias, these strategies have not yet achieved robust clinical responses in human gliomas. A powerful inhibitory microenvironment is thought to be the culprit. Mechanisms that determine the inhibitory microenvironment remain poorly understood. Herein we demonstrate that FYN, a downstream target of receptor tyrosine kinases signaling, inhibits the anti-glioma immune response. We utilized genetically engineered mouse models (GEMM) of glioma based on the Sleeping Beauty Transposon method. We examined the activities of FYN in NP (N-ras + shp53), NPA (NP + shATRX), and NPD (NP + PDGF overexpression) tumors. We also generated FYN knockdown glioma stem cells in vitro to induce gliomas in immune-competent and immune-deficient mice of varying genetic backgrounds (NSG, CD8-/-). Flow cytometry was used to characterize immune cells within the glioma microenvironment. Our results show that FYN knockdown in NP, NPA, or NPD GEMM of glioma reduced tumor progression and increased survival by 25–77%. GSEA analysis of differential expressed genes of WT vs. FYN knockdown gliomas revealed enrichments of gene ontologies related to immune functions. In NSG and CD8-/- immune-deficient mice, FYN knockdown failed to inhibits tumor growth and increase animal survival. These results suggest that FYN enhances tumor progression through changes in anti-glioma immune activation. Examination of tumor immune infiltrates by flow cytometry indicate a 50–70% reduction in powerful immune inhibitory myeloid derived cells (MDSCs) with no changes in the total level of CD8+ and CD4+ cells. Our results show for the first time that FYN reduces anti-glioma immune responses, likely through a reduction in inhibitory MDSCs. The specific inhibition of FYN exclusively within glioma cells, could improve the efficacy of anti-glioma immunotherapies.
TMOD-04. CHARACTERIZATION OF MUTANT IDH1 OLIGODENDROGLIOMAS
Authors: Heinz Rick , Holmen Sheri
Published: November 2019

Gliomas are the most common primary central nervous system malignancy in adults, but the molecular mechanisms responsible for their development and progression are not fully understood. Recent genomic analysis of World Health Organization grade II-III gliomas identifies 3 molecular subtypes of low grade glioma: no IDH mutation; IDH mutation without 1p/19q co-deletion; and IDH mutation with 1p/19q co-deletion. The latter, categorized as oligodendroglioma, commonly expresses loss of function mutations in CIC, FUBP1, and activation of PIK3CA. However, it is unknown if any of these mutations are sufficient to promote glioma development in cooperation with mutant IDH. Furthermore, research in oligodendroglioma is hampered by the lack of in vivo models of this specific glioma subtype. By utilizing the established RCAS/TVA somatic cell gene delivery method, mutant IDH1 can be expressed in the brains of mice. The tumorgenicity of other mutated genes associated with oligodendroglioma can be determined using additional methods such as conditional gene knockout and in vivo CRISPR-Cas9 mediated deletion. A mouse model for oligodendroglioma may identify new targetable genetic drivers of oligodendroglioma that will be useful for testing novel therapeutic strategies.
TMOD-06. MODELLING ADULT AND PAEDIATRIC GLIOBLASTOMA MULTIFORME (GBM) USING A GENE SCREEN-BASED APPROACH IN MICE AND HUMAN IPSC-DERIVED CEREBRAL ORGANOIDS
Authors: Antonica Francesco , Garilli Francesca , Del Mar Gardeazabal Bataller Maria , Santomaso Lucia , Tiberi Luca
Published: November 2019

Glioblastoma multiforme (GBM) represent the most devastating form of high-grade glioma (HGG) affecting adults and children. Despite a multi-therapeutic approach consisting in surgery, radio- and chemo-therapy the prognosis remains poor. Several models such as xenograft, animal models and recently organoids, have been developed in order to investigate the physiopathology of GBM. Although several mouse models (where either gain- or loss-of function of genes/pathway found altered in patients induce tumour formation) have been generated many aspects of how the tumour is formed, evolves, infiltrates and recurs after treatments remain unclear. Another challenge is the creation of proper GBM models showing intratumor heterogeneity found in the patient tumour but missing in the animal model generated so far. To overcome the lack of that human tumour characteristic, we decided to generate new model of GBM using a gene screen-based approach in mice. Firstly, we analysed the genes found amplified or mutated in GBM patients; secondly, we over-expressed the candidate genes (combination of multiple genes found to be mutated or amplified in specific GBM patients) in the subventricular zone (SVZ) of P2 mouse brain. Thirdly, we analysed the formation of tumour after 2 months. We over-expressed roughly 50 combinations in newborn mice and found that only 3 successfully led to the formation of lesions positive for proliferation and brain tumour marker (i.e. GFAP). We are currently characterising the tumours by DNA methylation analysis and RNA-seq (for further confirmation of the cancer subtype and intratumor heterogeneity) or investigating the cell of origin of the tumour. Moreover, we are testing the tumorigenicity of specific in GBM-amplified/mutated gene combinations in hiPSC-derived cerebal organoids. Our data suggest that a gene screen-based approach can be used for quickly and easily assaying the tumorigenicity of genes found amplified/mutated in GBM patients as well as the biology behind such complex process.
ANGI-01. IDENTIFICATION OF INVASION-DETERMINISTIC TRANSCRIPTION FACTORS IN GLIOBLASTOMA USING INTEGRATIVE TRANSCRIPTOME ANALYSIS
Authors: Park Junseong , Shim Jin-Kyoung , Eun Lee Jae , Jin Yoon Seon , Yoo Jihwan , Hyung Moon Ju , Hyun Kim Eui , Hee Chang Jong , Kang Seok-Gu
Published: November 2019

Glioblastoma (GBM) is one of the most lethal human tumors with a highly infiltrative phenotype. Although invasiveness is related to poor prognosis, no therapeutic intervention targeting invasion is available for treatment of GBM patient, partially due to the diversity and redundancy of invasion machinery genes. In this regard, additional identification of deterministic and causative targets for invasion is required. Invasiveness of GBM patients and matched tumorspheres (TSs) was quantified using MR images and collagen-based 3D invasion assays, respectively. Transcriptome of GBM samples were obtained using microarrays. The knockdown effects of invasion-deterministic transcription factors (TFs) were evaluated using western blot and mouse orthotopic xenograft model. This study is aimed to identify novel transcriptional regulatory networks, which can collectively modulate invasion-involved genes in GBM. After classification of 23 GBM patient-derived TSs into low and high invasion groups, we applied single sample gene set enrichment analysis using TF target gene sets. According to enrichment scores, TFs responsible for low (PCBP1) and high (STAT3 and SRF) invasiveness were identified. Consistently with computational prediction, knockdown of PCBP1 significantly increased invasion area, whereas knockdown of STAT3 or SRF significantly suppressed invasive properties in all tested TSs. Notably, MR images showed coherent patterns with invasion of originated TS, and high invasiveness was associated with poor prognosis. In addition, mouse orthotopic xenograft model using TSs with down-regulated STAT3 or SRF showed significantly prolonged survival time compared to control. We identified invasion-deterministic TFs in glioblastoma using integrative transcriptome analysis. Owing to relationship among these transcriptional regulatory networks, invasive phenotype, and prognosis, we suggest that these TFs as novel drug targets for GBM.
TMOD-26. MODELING GLIOBLASTOMA BY IMPLANTATION OF INTACT PATIENT-DERIVED ORGANOIDS INTO RODENT BRAINS
Authors: Nguyen Phuong , Jacob Fadi , Salinas Ryan , Zhang Daniel , Song Hongjun , Ming Guo-li
Published: November 2019

Glioblastoma multiforme (GBM) is the most common primary and aggressive brain tumors in adults with extremely poor prognosis and limited treatment options. A major hallmark of GBM is the rapid and diffused infiltration of tumor cells into the surrounding healthy tissue that contribute to tumor recurrence and therapeutic resistance. However, existing in vitro cell culture or in vivo xenograft models inadequately recapitulate the inter-tumoral and intra-tumoral heterogeneity which are key features of GBM. For example, common oncogenic drivers of GBM such as epidermal growth factor receptor (EGFR) amplification and EGFRvIII mutation do not persist in traditional in vitro models due to selection pressures, thus requires exogenous overexpression. Alternatively, EGFR statuses can be maintained in xenografted mice, but implantation of the primary GBM cells into the flank is required to first establish the tumor prior to secondary injection into the brains. Recently, we have established a novel protocol for culturing GBM tissue as organoids (GBOs) directly from patient tumor resection that retain many distinct cell populations in vitro with high fidelity evidenced by histological, whole-exome, bulk and single cell RNA analyses. Compared to prolonged generation time of previously established in vitro and xenograft models, our methodology is robust for generating GBOs within 1–2 weeks from initial resection. In addition, these GBOs can be readily xenografted into the adult mouse brains as an intact organoid, exhibit rapid and aggressive infiltration phenotypes, and maintains driver mutation EGFRviii within as little as one month. Consequently, they can be used to test in vivo treatment efficacies in a timely fashion. The presence of diverse cell types in this GBO model offers a promising platform for not only understanding of tumor biology, but also more strategic development of new therapies.
TMOD-31. ADAPTING ENGINEERED CELL THERAPIES TO UNDERSTAND AND OVERCOME GLIOBLASTOMA RESISTANCE USING INTEGRATED IN VIVO AND EX VIVO MODELS
Authors: Satterlee Andrew , Dunn Denise , Floyd Scott , Hingtgen Shawn
Published: November 2019

Genetically engineered neural stem cells (NSCs) are a promising therapy for the highly aggressive brain cancer glioblastoma (GBM), yet treatment durability remains a major challenge. We sought to define the events that contribute to dynamic adaption of GBM during NSC treatment and develop strategies to convert initial tumor kill into sustained GBM suppression. Using a unique hybrid tumor model treated with human skin-derived induced NSCs (iNSCs) releasing the pro-apoptotic agent TRAIL, we investigated how spatial distribution of tumor and iNSCs affects GBM adaption throughout recurrence. Serial bioluminescent imaging (BLI) was used to track tumor volumes in vivo, while a subset of mice were sacrificed 6, 13, and 20 days post-treatment to harvest brains and generate living ex vivo tissue slices. Live animal imaging showed iNSC-TRAIL treatment rapidly decreased tumor volumes when delivered into the primary tumor mass; however, minimal impact on tumor growth was observed when cells were delivered into distal regions of the brain. In contrast, high-resolution imaging of living brain sections showed extensive impacts of iNSC-TRAIL therapy that could not be visualized with BLI. The living slices showed iNSC-TRAIL treatment into the primary tumor decreased the solid, but not the invasive, tumor burden. Treatment into the lateral ventricles did impact tumor kill and was more effective at treating the invasive tumor burden and maintaining inhibition than treatment into the contralateral parenchyma. We next utilized the living tissue slices to explore the sensitivity of the recurrent tumors to TRAIL. When therapy was applied to slices harboring recurrent tumor, treatment again significantly reduced tumor volumes, suggesting that tumors had not acquired TRAIL resistance. These results informed an additional in vivo survival study and subsequent PCR analysis of untreated and recurrent tumors, and combine the fidelity of in vivo studies with the speed and spatial resolution of living brain slice technology.
TMOD-32. GL261 LUCIFERASE-EXPRESSING CELLS ELICIT AN ANTI-TUMOR IMMUNE RESPONSE: AN EVALUATION OF MURINE GLIOMA MODELS
Authors: Sanchez Victoria , Lynes John , Walbridge Stuart , Wang Xiang , Edwards Nancy , Nwankwo Anthony , Dominah Gifty , Obungu Arnold , Adamstein Nicholas , Dagur Pradeep , Wu Tianxia , Maric Dragan , Munasinghe Jeeva , Heiss John , K Nduom Edjah
Published: November 2019

Preclinical models that reliably recapitulate the immunosuppressive properties of human gliomas are essential to assess immune-based therapies. Intracranially injected GL261 cells are widely used as an immunocompetent animal model of glioma, but it is common practice to transfect these with luciferase to facilitate tumor monitoring during treatment. Our group has previously shown that the luciferase-expressing GL261 Red-FLuc cells create an inflammatory response when implanted intracranially. Now, we additionally explore the inflammatory response of GL261-Luc2 cells and demonstrate a similar host immune response occurs with this model as well. In our in vivo evaluation, C57BL/6 mice underwent stereotaxic, intracranial implantation with GL261, GL261 Red-FLuc or GL261-Luc2 cells at doses of 5x104cells/5mL or 3x105cells/5uL.MRIs were performed to monitor relative tumor growth. To assess intrinsic differences between cell lines, in vitro cytokine profiles were evaluated by proteome microarray. Kaplan-Meier survival analyses demonstrated median survival for mice implanted with GL261 cells at 5x104cells was 18 to 21 days. The GL261-Red FLuc implanted mice cells did not reach median survival at either tumor dose with greater than 60% of mice termed long-term survivors. Finally, mice injected with GL261-Luc2 cells at 3x105cells reached median survival at 23 days, but median survival was significantly prolonged for mice implanted with GL261-Luc2 at a dose of 5x104cells (37 days, with 40% becoming long-term survivors) compared to GL261 implanted mice. MRIs reveal differences in tumor growth that correspond with the differences in median survival between groups. In addition, proteomic analyses revealed significantly elevated inflammatory cytokines such as IFN-gamma, IL-7 and TNF-alpha in the supernatants of the GL261 Red-FLuc cells and GL261-Luc2 cells. Further immune characterization is ongoing. Our data suggests that GL261 Red-FLuc and GL261-Luc2 murine models elicit an anti-tumor immune response by increasing pro-inflammatory modulators which stimulate the tumoricidal function of immune cells in the tumor microenvironment.
SCIDOT-25. ENHANCING THE EFFICACY OF DRUG RELEASED FROM LOADED FIBRIN GLUE BY PHOTOCHEMICAL INTERNALIZATION (PCI)
Authors: Hirschberg Henry , Nguven Lina , Johnsen Julie
Published: November 2019

Although gross total resection of gliomas is often possible with current available techniques, almost all tumors recur due to the infiltrative nature of these tumors. Infiltrative tumor cells in normal brain are consequently protected by the blood brain barrier (BBB), greatly reducing the efficacy of chemotherapy. Localized per-operative methods of slow-release drug delivery, that bypass the BBB altogether, are therefore of considerable interest. Fibrin glue (FG) is a FDA approved compound often used during surgery. FG loaded with drugs has been studied as a localized controlled release vehicle but the quantity and release kinetics attainable for some drugs using FG are often inadequate. Photochemical internalization (PCI) has been demonstrated to significantly enhance the efficacy of several chemo-theraputic agents such as bleomycin (BLM) and doxorubicin (DOX). In particular PCI of BLM has been shown to be effective in sterilizing the tumor bed after marginal cytoreductive surgery. We have evaluated the ability of PCI to enhance the ability of BLM and DOX, released from loaded FG, to inhibit the growth of multi-cell glioma spheroids in vitro. Spheroid growth was monitored for 14 days. The results of the present study show that drug was released for up to 72 hours. The growth inhibition caused by either BLM or DOX was significantly enhanced by PCI. The photosensitizer AlPcS2a could also be loaded and released from FG allowing local delivery at the tumor site.
SCIDOT-38. DEVELOPMENT OF AN IMAGE-INFORMED MATHEMATICAL MODEL OF CONVECTION-ENHANCED DELIVERY OF NANOLIPOSOMES FOR INDIVIDUAL PATIENTS
Authors: Woodall Ryan , Hormuth David , Abdelmalik Michael , Wu Chengyue , Feng Xinzeng , Phillips William , Bao Ande , Hughes Thomas , Brenner Andrew , Yankeelov Thomas
Published: November 2019

186-Rhenium nanoliposomes (RNL) are an experimental theranostic being investigated for the treatment of recurrent Glioblastoma. While traditional external beam therapy exposures healthy tissue to radiation, RNL has the potential to deliver extremely large doses (> 2000 Gy) of localized radiation, minimally exposing surrounding tissue. RNL is delivered directly to the malignancy by convection-enhanced delivery (CED) via intracranial catheter. For this reason, accurate and precise delivery of RNL to the target region is an imperative. While models of CED for molecular agents exist, we know of no such models for CED of liposomal nanoparticles. To that end, we are developing a patient-specific advection-diffusion model of RNL delivery and distribution, informed by pre-delivery quantitative magnetic resonance imaging (MRI) parameters, and validated by intra-delivery single-photon emission computed tomography (SPECT). Apparent liposome diffusivity and interstitial hydraulic conductivity are spatially informed by diffusion weighted MRI, while the clearance of interstitial fluid is spatially informed by the T1 enhancement ratio after contrast agent delivery. The model output is compared to SPECT images at two time points, acquired mid-way through and immediately following the RNL infusion. At the time of submission, the model has been calibrated by patient-specific data to match the spatiotemporal distribution of RNL in four patients. After calibration, the concordance correlation coefficient between the model and SPECT measurements was 0.80 +/- 0.23 mid-way through the infusion volume, and 0.86 +/- 0.14 immediately post-infusion. The DICE coefficient between the modeled delivery volume and measured delivery volume was 0.86 +/- 0.10 mid-way through the infusion volume, and 0.81 +/- 0.14 immediately post-infusion (reported as mean +/- 95% confidence intervals). These results provide preliminary evidence that the model can capture the spatiotemporal distribution of RNL during and after delivery, and may enable physicians to better plan CED procedures for liposomal nanotherapeutics in the future.
SCIDOT-40. THERAPEUTIC GENOME EDITING AS A NOVEL TREATMENT FOR GBM
Authors: Rosenblum Daniel , Gutkin Anna , Peer Dan
Published: November 2019

Glioblastoma multiforme (GBM), is the most aggressive form of glioma, a brain tumor that arises from glial cells. GBM is considered a complex malignancy with multiple gene mutations, aberrations, and overexpression together with high infiltration rate and resistance to apoptosis. The current treatment consists of surgical resection, aggressive radiation and chemotherapy regimen. This therapeutic strategy had not changed since 2005 when the chemotherapy Temozolomide was approved. This therapeutic approach extended GBM patients’ life expectancy to approximately 15 months since diagnosis. Although recent progress in genomics and proteomics has paved the way for identifying potential therapeutic targets for treating GBM, the majority of these leading drug candidates remain ineffective. Therefore, novel and effective treatment to GBM presents an unmet need. Lipid nanoparticles (LNPs) are the most clinically advanced delivery platform to date for systemic administration of RNA therapeutics, with the recent approval of Patisiran, siRNA encapsulating LNPs. In recent years, several gene editing technologies have been discovered in bacteria, enabling precise and permanent manipulations at the DNA level. The most advanced and versatile system is based on the CRISPR nuclease Cas9. The recognition of its target chromosomal DNA by Cas9 results in a site-specific double-strand break (DSB), that eventually results in gene disruption. This approach opens multiple venues for research and treatment of diseases including cancer. We have utilized CRISPR encapsulating LNPs to promote a therapeutic gene editing by disrupting key GBM survival genes in vitro in murine and human GBM cell lines as well as in vivo in an aggressive syngeneic GBM mouse model. Our results suggest that treatment with our LNPs based system can specifically and efficiently target GBM cells in vitro and in vivo. Our CRISPR-LNPs based platform could potentially mature to a clinical trial, and ultimately might become a new therapeutic modality in GBM.
SCIDOT-45. MAGNETIC FIELD STRUCTURE OF THE HÆLO™ PEDIATRIC SYSTEM
Authors: Peterson Eric , Figueroa Xavier , Butters Mike , Woodcock Amanda , Brown Dan , Ferguson Ken
Published: November 2019

BACKGROUND

The Hælo pediatric system, an investigational medical device intended to treat diffuse midline glioma (DMG), emits a magnetic field intended to disrupt the growth of DMG tumors. The Hælo headcoil is positioned on the back of the patient’s head; the field envelopes the patient’s head and the specific frequencies of the field penetrate the skull and brain tissue without any significant attenuation.

METHODS

The shape and intensity of the magnetic field emitted by the Hælo headcoil were measured using a triaxial magnetic sensor, which measures the flux density along three orthogonal axes. The headcoil is designed to conform to the back of the head and is not planar. To account for the slight difference in field shape due to the coil’s convex shape, the field was measured with the coil held in both a convex and concave position relative to the central plane. A custom-designed measurement system was used to position the sensor in a three-dimensional grid with 1 cm resolution (approximately 10,000 individual measurements for each coil position.) A test field with the same flux density produced by the Hælo pediatric system treatment field was used. The root mean square of the field along each axis was calculated and combined to yield the total flux density at each position. The datasets from each coil position were combined to create a complete three-dimensional map of the field generated by the headcoil.

RESULTS

The greatest flux density is proximal to the coil. The test field ranged from approximately 200 mGauss near the headcoil to 100 mG within the ellipsoid formed by the headcoil.

CONCLUSION

The field of the Hælo pediatric system encompasses the brain and portions of the brainstem, and thus delivers a targeted magnetic therapeutic to the common tumor locations for DMG.