bluuebunny/crossref_metadata_2025 huggingface dataset:
CMET-40. IMPACT OF WHOLE BRAIN RADIOTHERAPY ON LEPTOMENINGEAL METASTASIS FROM NON-SMALL CELL LUNG CANCER
Authors: Wen Lei , Zhou Zhaoming , Zhen Junjie , Zhou Cheng , Lai Mingyao , Shan Changguo , Cai Linbo
Published: November 2019

BACKGROUND

Leptomeningeal metastasis (LM) is a detrimental complication of patients with non-small cell lung cancer (NSCLC) and its incidence has increased due to recent improvements in survival. The aim of this study was to assess the impact of whole brain radiotherapy (WBRT), chemotherapy and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) on survival.

METHODS

Seventy-four consecutive patients diagnosed with LM from NSCLC between 2009 and 2018 in Sanjiu Brain Hospital were retrospectively reviewed. Survival was assessed by Kaplan-Meier analyses.

RESULTS

The median age was 54.5 (range 30–76) years. LM were diagnosed by MRI (36/74), cytology (4/74), or both (34/74). Eighteen patients (24.3%) were diagnosed at the initial presentation of lung cancer. Forty-seven (63.5%) patients harboring EGFR positive mutation while other twenty-seven patients (36.5%) were EGFR wild type. The median overall survival from diagnosis of LM was 8.1 months (95% confidence interval: 5.2 to 11.0). Patients who received EGFR-TKIs after LM had longer survival than those who did not (10.5 vs. 4.4 months, p＜0.001). No significant differences in survival were seen between patients who were treated with WBRT and those without, whether in EGFR mutation positive patients (11.6 vs. 15.0 months, p=0.353), or in EGFR wild type ones (5.1 vs. 3.3 months, p=0.116). Similarly, intravenous chemotherapy after LM had no impact on overall survival (7.5 vs. 8.1 months, p=0.9).

CONCLUSION

Median overall survival was higher than historical experience in our retrospective analysis. Survival was not improved by WBRT or intravenous chemotherapy. EGFR-TKIs could prolong survival of patients with LM from NSCLC.
COMP-06. PROBING GLIOBLASTOMA AND ITS MICROENVIRONMENT USING SINGLE-NUCLEUS AND SINGLE-CELL SEQUENCING
Authors: Peng Sen , Rath Sanhita , Vuong Connor , Bollam Saumya , Eschbacher Jenny , Mehta Shwetal , Sanai Nader , Kim Seungchan , Berens Michael , Dhruv Harshil
Published: November 2019

Single-cell (scSeq) and single-nucleus sequencing (snSeq) are powerful tools to investigate cancer genomics at single cell resolution. Multiple studies have recently illuminated intratumoral heterogeneity in glioblastoma, however, the majority focused on molecular complexity of tumor cells, without taking into account unexplored host cell types that contribute to the microenvironment around tumor. To address the glioblastoma microenvironment composition and potential tumor-host interactions, we performed deep coverage sequencing of freshly resected primary GBM patient tissue without implementing any tumor enrichment strategies. The sequencing resulted in 902 cells and 1186 nuclei, respectively, passing quality control and with low mitochondrial gene percentage. We customized reference transcriptome by listing gene transcript loci as exons to take into account immature RNA, which greatly improved the alignment rate for single-nucleus data. We applied Cell Ranger pipelines (Version 3.0.2) and Seurat package (Version 2.3.1) and discovered 10 clusters in both scSEQ and snSEQ. Pathway analysis of each cluster signature in scSeq data along with known GBM microenvironment cell signatures revealed glioma tumor population along with surrounding microglia/macrophages, astrocytes, pericytes, oligodendrocytes, T cells and endothelial cells. The analysis of snSEQ was able to capture the majority of cell types from patient tissues (tumor and microenvironment cells), but interestingly presented different cell type composition in microenvironment cell types such as microglia/marcophages. Integrating single-cell and single-nucleus transcriptomic data using canonical correlation analysis facilitated a comparison of snSEQ and scSEQ, contrasting depiction for certain cell types (e.g. NKX6-2 gene in Oligodendrocytes). Differential analysis of pathways between tumor and microenvironment cells unveiled potentially rewired pathways such as double strand break repair pathway. Our results demonstrate the cellular diversity of brain tumor microenvironment and lay a foundation to further investigate the individual tumor and host cell transcriptomes that are influenced not only by their cell identity but also by their interaction with surrounding microenvironment.
COMP-09. A CANCER DRUG ATLAS ENABLES PREDICTION OF PARALLEL DRUG VULNERABILITIES OF GLIOBLASTOMA
Authors: Narayan Ravi , Molenaar Piet , Cornelissen Fleur , Wurdinger Tom , Koster Jan , Westerman Bart
Published: November 2019

Personalized cancer treatments using synergistic combinations of drugs is attractive but proves to be highly challenging. The combinatorial nature of such problems results in an enormous parameter space that cannot be resolved by empirical research, i.e. testing all combinations for all molecularly defined tumors. In addition, effective drug synergy is hard to predict. Here we present an approach to map data of drug-response encyclopedias and represent these as a drug atlas. This atlas consists of a framework of chemotherapeutic responses that represents a drug vulnerability landscape of cancer. Based on data from the literature we found that many synergistic drug combinations show distinct inter therapy responses and drug sensitivities. We confirmed this by performing a drug combination screen against glioblastoma where we used 270 combination experiments. From the identified dual therapies we were able to predict and validate a triple drug synergy which was validated in vivo. This new and generalizable strategy opens the door to unforeseen personalized multidrug combination approaches.
COMP-11. SINGLE CELL MASS CYTOMETRY SIGNALING PROFILES AND A NOVEL COMPUTATIONAL TOOL IDENTIFY HIGH RISK GLIOBLASTOMA CELLS
Authors: Leelatian Nalin , Sinnaeve Justine , Mistry Akshitkumar , Barone Sierra , Diggins Kirsten , Greenplate Allison , Bartkowiak Todd , Roe Caroline , Weaver Kyle , Thompson Reid , Chambless Lola , Mobley Bret , Irish Jonathan , Ihrie Rebecca
Published: November 2019

In glioblastoma, changes in signaling, gene sequence, copy number, or transcript expression can define patient subgroups, but these subgroups are not yet associated with differential outcome for most patients with high-risk, IDH wild-type disease. Single cell interrogation of phospho-protein signaling has successfully revealed novel cell types associated with patient outcomes in blood cancers, suggesting that a comparable approach could be used in brain tumors. The goal of this study was to combine a single cell phospho-protein profiling approach with novel, automated computational analysis to identify abnormal glioblastoma cells that stratify patient clinical risk. Effective tissue dissociation strategies and validated antibody panels were created for mass cytometry analyses of resected glioblastoma tissue. These panels simultaneously measured 45 determinants of neural and glioma cell identity, including transcription factors, phospho-proteins, and surface receptors. 28 glioblastoma tumors were stained and analyzed using traditional gating, existing computational tools, and a new risk assessment population identification algorithm (RAPID, https://www.biorxiv.org/content/10.1101/632208v3). RAPID revealed two malignant cell types closely associated with differential patient outcomes. Glioblastoma negative prognostic (GNP) cells were associated with poor survival and defined by phospho-protein signaling in cells with aberrant neural developmental phenotypes. Glioblastoma positive prognostic (GPP) cells were associated with better progression free survival and defined by increased immunogenic signaling. A Cox proportional-hazards regression model was created to assess the influence of GNP and GPP cells on OS and PFS as continuous variables while accounting for other well-known clinical predictors. Each 1% increase of GNP cells was associated with an 7% increase in annual mortality rate (HR=1.07 [95% CI 1.03–1.12], p=0.001). Tumors containing GNP cells also significantly lacked CD45+ immune cell infiltration (Pearson r=-0.8). The signaling events that define these clinically significant glioblastoma cells represent a useful molecular classification, may indicate responsiveness to immunotherapy, and are themselves important targets of opportunity for new therapeutic approaches.
COMP-13. EARLY TUMOR VOLUME EVOLUTION ADAPTIVELY PREDICTS PATIENT-SPECIFIC RESPONSE AND PROGRESSION RISK TO RADIOTHERAPY, PEMBROLIZUMAB, AND BEVACIZUMAB IN RECURRENT HIGH-GRADE GLIOMA IN A PHASE I TRIAL
Authors: Glazar Daniel , Brady Rene , Howard Rachel , Grass Daniel , Arrington John , Yu Michael , Raghunand Natarajan , Sahebjam Solmaz , Enderling Heiko
Published: November 2019

PURPOSE/OBJECTIVES

We set out to predict response and progression risk in recurrent high-grade glioma patients treated with hypofractionated stereotactic radiation plus pembrolizumab and bevacizumab (NCT02313272). At present RANO criteria define progression as 25% increase in sum of the products of perpendicular diameters of enhancing lesions compared with the smallest tumor measurement (either at baseline or best response) or significant increase in T2/FLAIR non-enhancing lesion on stable or increasing doses of corticosteroids. To this extent, a predictive model is needed to adaptively learn and forecast individual response to therapy. We evaluate if early tumor volume evolution can train a mathematical model to predict subsequent response to therapy.

MATERIALS/METHODS

We develop a mathematical model that describes patient-uniform tumor growth rate and initial pembrolizumab and bevacizumab responses, and patient-specific treatment response dynamics. A total of 154 radiology scans were delineated to derive longitudinal tumor volumes of 26 patients. In a leave-one-out study, patient-uniform model parameters are derived and then applied to the left-out patient to adaptively learn treatment response dynamics to forecast tumor volume evolution and progression risk. Model prediction performance is evaluated based on classification accuracy, including sensitivity and specificity.

RESULTS

Patient-uniform glioma growth rate and initial treatment response rates are estimated to achieve acceptable fits to the longitudinal data of all untrained patients with R2 = 0.81 [0.75, 0.89]. Response dynamics are predicted with high accuracy (0.78 [0.76, 0.79]), with positive and negative predictive values of 0.90 [0.86, 0.92] and 0.81 [0.78, 0.86], and sensitivity and specificity of 0.71 [0.69, 0.73] and 0.88 [0.83, 0.91] respectively.

CONCLUSIONS

Two patient-specific parameters in a mathematical model can be adaptively learned from early tumor volume evolution to predict subsequent response to therapy and progression risk for individual patients. Future validation is required in an independent dataset and prospective evaluation in another clinical trial.
COMP-15. MOLECULAR AND CLONAL EVOLUTION IN RECURRENT METASTATIC GLIOSARCOMA
Authors: Anderson Kevin , Tan Aaron , Parkinson Jonathon , Back Michael , Kastela Marina , Newey Allison , Brewer Janice , Wheeler Helen , Hudson Amanda , Amin Samirkumar , Johnson Kevin C , Barthel Floris , Verhaak Roel , Khasraw Mustafa
Published: November 2019

Gliosarcoma, a World Health Organization grade IV glioma, is a rare variant of glioblastoma (GBM) that contains distinct glial and mesenchymal components. Histologically, the glial component matches criteria for glioblastoma, and both components share genetic alterations common to GBM. Though GBM are known to strongly infiltrate surrounding tissue, extracranial metastases are rare, and the underlying mechanisms are still poorly understood. We present a rare case of a 37-year-old woman who was initially diagnosed with IDH wild-type gliosarcoma in the frontal lobe and later developed two local recurrences and extracranial metastases to the vertebral and pelvic bones. In order to understand the clonal relationships between four tumor instances and the origin of metastasis, we performed whole genome sequencing of the intracranial tumors and the tumor located in the right iliac bone. We compared mutational and copy number profiles and inferred tumor clonal phylogeny. The tumors harbored shared GBM alterations including TP53, NF1, and RB1 mutations and CDKN2A deletion. Comparisons of the metastatic to intracranial tumors highlighted a high similarity in molecular profiles, but contrasting evidence regarding the origin of the metastasis. The metastasis was most similar to the second recurrence with respect to mutational signatures, reflected in the activity of signatures associated with defective DNA mismatch repair not observed in the primary or first recurrent tumor. The metastasis was most similar to the first recurrence with respect to copy number profile; both samples displayed widespread amplifications indicative of whole genome doubling. Results of subclonal reconstruction suggested that the second recurrent and metastatic tumors originated from more than one clone and developed subclone-specific driver mutations. The branching phylogeny and copy number profiles suggest the metastasis was largely derived from the first recurrence. This is the first analysis of clonal evolution of extracranial metastasis in gliosarcoma and highlights alterations driving aggressive GBM progression.
DDIS-07. IDENTIFICATION OF DRUGGABLE MOLECULAR TARGETS IN MENINGIOMA
Authors: Tran Anh , Zhang Lyndsee , Sahm Felix , Scholtens Denise , Horbinski Craig
Published: November 2019

BACKGROUND

Meningioma is the most common primary intracranial tumor, with nearly 30,000 new cases in the US every year. Many meningiomas invade the brain, recur, and become radioresistant, causing severe disability and lethality. Prior work by Sahm et al. showed that meningiomas have consistent patterns of global CpG methylation, and that those patterns are better at prognostic stratification than traditional WHO grading (Lancet Oncol. 2017 May;18(5):682–694). In this study, we hypothesized that specific methylation events could provide further insights as to the signaling pathways driving more aggressive behavior, and identify druggable targets.

METHODS

We analyzed the Illumina 450k CpG methylation profiles of 493 meningiomas that were published in Lancet Oncology, searching for associations between methylation at individual CpG sites and progression-free survival (PFS). Pathway enrichment analyses were performed using gProfiler and Reactome for genes closest to significant CpG sites, followed by screening for candidate drugs targeting the pathways that were linked with malignant behavior using the ReactomeFIViz Cytoscape Plugin.

RESULTS

Our analyses revealed 981 genes in which methylation of mapped CpG sites was consistently associated with either shorter PFS (positive hazard ratios (HRs)) or longer PFS (negative HRs) at FDR-adjusted p< 0.05. Methylation of genes encoding proteins involved in G-protein coupled receptor (GPCR) signaling pathways, especially G-alpha (s) and olfactory signaling pathways, showed pronounced association with PFS. We identified 134 anticancer drugs that target the GPCR pathway, including docetaxel and raloxifene hydrochloride, which specifically target G alpha (s) subcomponents. Both are FDA-approved, but no published data exist on their use in meningiomas.

CONCLUSIONS

This project is advancing our understanding of the molecular pathways driving aggressive behavior in meningioma, and is identifying existing drugs that can be repurposed to treat this tumor.
DDIS-20. IMIPRIDONE STRUCTURE ACTIVITY RELATIONSHIP UNCOVERS ONC206 AS THE NEXT BITOPIC DRD2 ANTAGONIST FOR ONCOLOGY WITH DIFFERENTIATED RECEPTOR PHARMACOLOGY
Authors: Prabhu Varun , Cuoco Caroline , Jung Jinkyu , Rahman Kawakibi Abed , Willette Blair , Day Marilyn , Anantharaman Lakshmi , Charter Neil , Rucker Joseph , Doranz Benjamin , Oster Wolfgang , Stogniew Martin , Gilbert Mark , Benjamin Free R , Sibley David , Allen Joshua
Published: November 2019

ONC201 is the first bitopic antagonist of dopamine receptor D2 (DRD2) in oncology clinical trials, which have shown that the small molecule is well tolerated and induces durable tumor regressions in H3 K27M-mutant glioma patients. ONC201 possesses a unique tri-heterocyclic core structure that prompted a medicinal chemistry exploration following its successful clinical translation. Chemical derivatization of the ONC201 pharmacophore from an angular to a linear isomer ablated DRD2 antagonist activity and anti-cancer activity, indicating the core structure integrity is critical. A series of analogs that share the same core structure, called imipridones, were profiled for modulation of β-arrestin recruitment to GPCRs and anti-cancer efficacy. The profiled imipridones exhibited a heterogeneous spectrum of GPCR agonist/antagonist activity that was exclusive to Class A GPCRs. The addition of electron withdrawing groups to one of two peripheral benzyl rings enhanced the potency of GPCR engagement and anti-cancer effects, while derivatization of the other benzyl ring was inactivating. Among the GPCR hits identified, maximal variance in imipridone GPCR antagonism was identified for DRD2/DRD3. ONC206 emerged as the most selective and potent antagonist for DRD2/DRD3 with a Ki of ~320nM for DRD2 with complete specificity across human GPCRs and complete DRD2 antagonism. Schild analyses of ONC206 in cAMP and β-Arrestin recruitment assays revealed hallmarks of non-competitive DRD2 antagonism, unlike antipsychotics but similar to ONC201. Shotgun mutagenesis across DRD2 identified 7 residues critical for ONC206-mediated antagonism at orthosteric and allosteric sites. Six residues were critical for ONC201 and ONC206, however the impact varied between the two compounds and one allosteric residue was exclusive to ONC206. Structural mapping revealed that some ONC206-critical allosteric residue interactions are located at the interface of TM-IV and –V that mediates the DRD2 homodimer interface. Thus, ONC206 is a bitopic DRD2 antagonist that may be poised to address oncogenic DRD2 monomers or dimers.
DDIS-26. HIGH-THROUGHPUT DRUG SCREENING OF MENINGIOMAS IDENTIFIES HDAC INHIBITORS AS PROMISING TARGETS ACROSS GRADES
Authors: Tatman Philip , Fringuello Anthony , Wroblewski Teddy , Scherer Sam , Foreman William , Ryan Ormond D , Damek Denise , Lillehei Kevin , Jensen Randy , Graner Michael
Published: November 2019

Meningiomas are a common central nervous system (CNS) tumor, accounting for one third of CNS neoplasms. To date, no FDA approved pharmacotherapy exists for meningiomas. In an effort to identify potential treatments for meningiomas we created a culture system that allows us to grow and screen tumors across hundreds of compounds within two weeks of resection. We screened 32 meningiomas, six of which were World Health Organization (WHO) grade II, against the National Cancer Institute’s (NCI) FDA-approved cancer compound library and Caymen Chemical’s epigenetic inhibitor library, totaling to more than 300 compounds. The NCI library was screened at 1um, and the Caymen library was screened at 5um. Each library was screened in triplicate, allowing us to calculate statistical significance. We used an MTS assay to determine cell viability after three days. The data was background subtracted and normalized to controls. Significant changes in cell viability were determined for individual drugs using a Mann-Whitney-U test compared to untreated controls. On average, regardless of grade, 5.9 compounds per hundred screened significantly reduced tumor viability. We identified four compounds in the NCI FDA-approved library that reduced cell viability, on average across all tumors screened, by at least 50%: romidepsin, panobinostat, daunorubicin, and carfilzomib. Using the same criteria, we identified the following drugs from the Caymen epigenetic library: LAQ824, panobinostat, and HC toxin. Of the six compounds implicated as possible treatments for meningiomas, four are histone deacetylase (HDAC) inhibitors. HDAC inhibitors may represent a promising target for the treatment of meningiomas. Based on this data, we have begun in vivo work using PDX mouse models to investigate the therapeutic potential of HDAC inhibitors for the treatment of meningiomas.
DDIS-29. BRAIN-PENETRANT MICROTUBULE-TARGETING AGENT, ST-401, KILLS GLIOBLASTOMA THROUGH A NOVEL MECHANISM
Authors: Horne Eric , Xu Cong , Vicente Juan-Jesus , Cimino P J , Wagenbach Michael , Hamel Ernest , Gussio Rick , Diaz Philippe , Uhlenbruck Benjamin , Deckwerth Thomas , Wordeman Linda , Holland Eric , Stella Nephi
Published: November 2019

Glioblastomas are particularly sensitive to mitotic disruption when compared with nonmalignant cells and thus microtubule-targeting agents (MTA) represent promising therapeutics to treat patients with glioblastomas; but few such compounds pass the blood brain barrier. We developed a series of modified carbazoles, evaluated their anti-cancer activity in glioblastoma cells in culture and identified ST-401 as the most potent compound (IC50, 10 – 102 nM, depending on the cell line). Testing of ST-401 on the NCI 60 cancer cell panel indicated that its anti-tumor activity does not correlate with any of the compounds tested thus far through this platform but showed weak correlations for taxol (p=0.46) and vinblastine (p=0.34). Thus, ST-401 may kill cancer cells through a novel mechanism related to disruption of MT function. Biochemical analysis indicates that ST-401 binds to the colchicine site of tubulin and inhibits tubulin assembly. Real-time imaging of MT dynamics in cells in culture shows that ST-401 reduces MT assembly rates but in a reversible fashion. ST-401 potently blocks mitotic progression and triggers cell death in multiple glioblastoma lines in culture, including patient-derived glioblastomas of the proneural, mesenchymal and classical subtypes. We established the maximum tolerated dose (MTD) of ST-401 in mice (20 mg/kg/bdip) and found that its acute i.p. injection results in micromolar amounts of ST-401 in mouse brain. Using this treatment regimen, we found that ST-401 reduces tumor growth and doubles overall survival in a human tumor xenograft mouse model system. ST-401 also increases by 2-fold overall survival in the genetic RCAS-PDGF glioblastomas mouse model treated with standard care (radiation and Temodar® treatments). Histological analysis of RCAS-PDGF glioblastoma tissue shows that ST-401 triggers mitotic arrest of glioblastoma cells. ST-401 represents a promising lead compound for the treatments for patients diagnosed with glioblastomas.
EPID-07. HEMATOLOGICAL ADVERSE EVENTS IN GLIOBLASTOMA PATIENTS TREATED WITH TEMOZOLOMIDE
Authors: Garcia Catherine , Myint Zin , Jayswal Rani , Butts Allison , Weiss Heidi , Villano John
Published: November 2019

BACKGROUND

Temozolomide (TMZ) is the cornerstone for glioblastoma (GBM) treatment. A significant proportion of patients develops hematologic toxicities with limited investigations on outcomes and risk factors for their development.

METHODS

Our study combines data from the two largest group trials, RTOG 0525 and RTOG 0825, to analyze serious hematologic adverse events (HAE) associated with TMZ therapy for GBM. We analyzed frequency and outcomes of HAE during chemoradiation.

RESULTS

1154 patients were evaluated with a median age of 57 years. Over 79% of patients developed HAE during the entire course of GBM treatment. During chemoradiation the most common HAE during chemoradiation was lymphopenia (41.5%), followed by thrombocytopenia (39.0%), and anemia (35.3%). Of these, 34.1% were severe (Grade 3 or 4) and 65.9% were mild (grade 1 or 2). During maintenance the most common HAE was leukopenia (50.7%), followed by neutropenia (50.4%), and lymphopenia (45.3%). MGMT methylation was not associated with HAEs. A history of HAEs during chemoradiation was a protective factor for developing HAEs during maintenance. MGMT methylated and age younger than 50 were protective factors for mortality. Patients that presented HAEs anytime during treatment had a longer overall survival and progression free survival. There was no significant difference in survival between mild or severe HAEs.

CONCLUSION

HAE are common during chemoradiation with TMZ for GBM, but are more commonly grade 1 or 2 per CTCAE. HAE during GBM treatment is associated with decreased progression free survival and overall survival.
EPID-30. A TWITTER-BASED NETWORK ANALYSIS OF BRAIN TUMOR SOCIAL MEDIA (#BTSM)
Authors: Feliciano Josemari , Salmi Liz , Blotner Charlie , Hayden Adam , Nduom Edjah , Kwan Bethany , Katz Matthew , Claus Elizabeth
Published: November 2019

BACKGROUND

The Brain Tumor Social Media (#BTSM) Twitter hashtag was founded in February 2012 as a disease-specific hashtag for brain tumor patients. To understand #BTSM’s role as a patient support system we describe user descriptors, growth, interaction, and content sharing.

METHODS

We analyzed all tweets containing #BTSM from 2012 to 2018 using the Symplur Signals platform to obtain data and to describe Symplur-defined user categories, tweet content, and trends in use over time. We created a network plot with all publicly-available retweets involving #BTSM in 2018 to visualize key stakeholders and their connections to other users.

RESULTS

From 2012 to 2018, 59764 unique users participated in #BTSM, amassing 298904 tweets. The yearly volume of #BTSM tweets increased by 264% from 2012 to 2018 with #BTSM constantly trending in the top 15 list of disease hashtags, as well the top 15 list of tweet chats. Patient advocates generated the most #BTSM tweets (33.0%) while advocacy groups, researchers, caregivers and doctors, generated 28.8%, 7.0%, 4.6% and 3.9%, respectively. Physician use, although still low, has increased over time. The 2018 network plot of retweets including #BTSM identifies a number of key stakeholders from the patient advocate, patient organization, and medical researcher domains and reveals the extent of their reach to other users.

CONCLUSIONS

From its start in 2012, #BTSM has grown exponentially over time. We believe its growth suggests its potential as a global source of brain tumor information for patients, advocates, patient organizations as well as healthcare professionals and researchers.
EPID-31. EFFICIENT STUDY OF SURGICALLY TREATED MENINGIOMA THROUGH CLINICAL DATA STANDARDIZATION
Authors: Au Karolyn , Nassiri Farshad , Drummond Kate , Jenkinson Michael , Santarius Thomas , Barnholtz-Sloan Jill , jungk Christine , DiMeco Francesco , Galanis Evanthia , Saladino Andrea , Zhou Yueren , Suppiah Suganth , Aldape Kenneth , Zadeh Gelareh , Poisson Laila
Published: November 2019

With increasing epidemiological and biological studies on meningiomas, standardized clinical data capture will be necessary to interpret results across studies and to translate them to clinical practice. To meet this need for consistent clinical data capture, the International Consortium on Meningioma, has developed a set of common data elements (CDEs), to be used across clinical and biological research. Building from terminology used in clinical practice and ongoing studies, we used a consensus-of-experts approach to arrive at a set of standardized and vetted data elements. Areas of focus include patient characteristics, patient history, radiological and intra-operative description, histological diagnosis and molecular testing, non-surgical interventions, and surveillance. These data elements are implemented in Research Electronic Data Capture (REDCap) forms. With REDCap implementation, components of the CDE set can be selected and instituted in a local REDCap instance for efficient study start-up. The scope of the current CDE set focuses on surgically treated meningioma. However, modular forms provide flexibility and to allow the scope to be expanded to include non-surgically treated meningioma. Dissemination plans are underway to introduce the CDEs to neuro-oncology researchers and clinicians through publication and presentations, where feedback will be solicited. Adoption of CDEs for research will improve consistency and interpretability across studies, expediting research in this frequently occurring tumor.
EXTH-03. TRIPTOLIDE, A NOVEL THERAPEUTIC AGENT FOR IDH1-MUTATED GLIOMA
Authors: Yu Di , Liu Yang , Xu Guowang , Yang Chunzhang
Published: November 2019

BACKGROUND

Isocitrate dehydrogenase (IDH1/2) mutations are common genetic abnormalities in human malignancies, which result in neomorphic enzyme activity that catalyzes 2-hydroxyglutarate (2-HG) production. While IDH mutations are recognized as critical cancer-associated genetic changes, the therapeutic options for IDH-mutated cancers remain limited.

METHODS

In the present study, we investigated the reactive oxygen species (ROS) scavenging pathways in patient-derived IDH1-mutated cells. Further, we investigated the protective role of glutathione de novo synthesis for IDH1-mutated cancer cells. Finally, we evaluated triptolide, a diterpenoid epoxide derived from Tripterygium wilfordii, as an experimental therapeutic for IDH1-mutated cells and xenografts.

RESULTS

We discovered that the neomorphic activity of IDH1 mutant enzyme triggers metabolic depletion and a substantial elevated burden of ROS scavenging in cancer cells. The nuclear factor erythroid 2-related factor 2 (NRF2)-guided antioxidant pathway plays a key role in maintaining redox homeostasis for IDH1-mutated cells. Triptolide serves as a potent inhibitor of NRF2 through enhancing the NRF2 ubiquitination and subsequently proteasomal degradation. Additionally, triptolide compromises the de novo synthesis of glutathione via suppression of NRF2-guided transcription of SLC7A11, which encodes cystine/glutamate transporter (xCT). Reduced availability of glutathione results in overwhelming oxidative damage in DNA and lipid, which translates into severe cytotoxicity and reduced xenograft expansion of IDH1-mutated cells.

CONCLUSION

Overall our findings highlight triptolide as a valuable synthetic lethality approach for IDH1-mutated malignancies by targeting NRF2-guided redox homeostasis.
EXTH-04. BLOCKADE OF NRF2/GLUTATHIONE METABOLISM AS A SYNTHETIC LETHALITY APPROACH FOR IDH1-MUTATED GLIOMA
Authors: Liu Yang , Lu Yanxin , Celiku Orieta , Li Aiguo , Yang Chunzhang
Published: November 2019

BACKGROUND

Mutations in isocitrate dehydrogenase (IDH1/2) are frequent genetic abnormalities in human malignancies. IDH1/2-mutated cancers are a recently defined disease entity with distinctive patterns of tumor cell biology, metabolism and resistance to therapy. Molecular targeting approaches against this disease cluster remain limited.

METHODS

We investigated the redox homeostasis in IDH1 mutant-transduced cells and patient-derived brain tumor initiating cells. The importance of antioxidant genes was confirmed through COX regression analysis on a large cohort of lower grade glioma. We investigated the biologic impact of Nuclear factor erythroid 2-related factor 2 (NRF2) on the glutathione de novo synthesis in IDH1-mutated cells. Finally, we evaluated the value of targeting NRF2/glutathione metabolic pathway as a potential synthetic lethality approach for IDH1-mutated cell in vitro and in vivo.

RESULTS

We discovered that acquisition of cancer-associated IDH1 mutants results in constitutive activation of NRF2-governed cytoprotective pathways through decoupling of NRF2 from its E3 ligase Kelch-like ECH-associated protein 1. NRF2 mediated the transcriptional activation of GCLC, GCLM and SLC7A11, which strengthens the glutathione de novo synthesis, and relieves the metabolic burden derived from IDH1 mutant neomorphic activity. Blockade of the NRF2/glutathione metabolic pathway synergizes with the elevated intrinsic reactive oxygen species, which results in overwhelming oxidative damage in IDH1-mutated cells, as well as a substantial reduction in tumor cell proliferation and xenograft expansion.

CONCLUSION

Our findings suggest that blockade of the NRF2/glutathione synthetic pathway is a novel targeting strategy for IDH1-mutated malignancies.
EXTH-12. RADIATION ENHANCES MELANOMA RESPONSE TO IMMUNOTHERAPY AND SYNERGIZES WITH BENZODIAZEPINES TO PROMOTE ANTI-TUMOR ACTIVITY
Authors: Pomeranz Krummel Daniel , Nasti Tahseen , Izar Benjamin , Xu Maxwell , Lowder Lindsey , Press Robert , Kaluzova Milota , Kallay Laura , Rupji Manali , Burnham Andre , Li Guanguan , Ahmed Taukir , Rosen Havi , Connolly Erin , Keskin Havva , Ben Thomas Midhun , Curran Walter , Kudchadkar Ragini , Weinberg Brent , Olson Jeffrey , Schniederjan Matthew , Neil Stewart , Su Jing , Lawson David , Cook James , Jenkins Andrew , Kowalski Jeanne , Khan Mohammad , Sengupta Soma
Published: November 2019

Melanoma brain metastases (MBM) occur in ~50% of advanced melanoma patients. It is unclear if systemic therapies synergize with radiotherapy (RT) and what the impact of RT timing has on efficacy. We find that RT followed by ICI (immune checkpoint inhibitors) (RTàICI) improves MBM patient survival compared to other combination strategies, also shown here in a murine melanoma model. RNA-seq of MBM tumors in the RTàICI group exhibit overrepresentation of genes implicated in NFKB signaling. There is also expression of GABAA receptor subunits across both treatment groups. We show that melanoma cells express functional GABAA receptors and that benzodiazepines impair tumor growth. Combination of sub-lethal RT doses with benzodiazepine results in significant ipsilateral and out of field abscopal anti-tumor activity, which is associated with enhanced tumor infiltration with poly-functional CD8 T-cells. This study provides evidence that RT enhances MBM response to ICI and synergizes with benzodiazepines to promote anti-tumor activity.
EXTH-15. INCREASING THE TRAFFICKING OF DENDRITIC CELLS VIA CXC CHEMOKINE SIGNALING PATHWAY LEADS TO IMPROVED ANTI-TUMOR EFFICACY OF DENDRITIC CELL VACCINES
Authors: Dastmalchi Farhad , Karachi Aida , Yang Changlin , Azari Hassan , Vlasak Alex , Saia Megan , Mitchell Duane , Rahman Maryam
Published: November 2019

Dendritic cell (DC) vaccine efficacy is directly related to the efficiency of DC migration to the lymph node after delivery to the patient. In this research we discovered increasing cell migration by utilizing sarcosine improved anti-tumor efficacy. We hypothesized that sarcosine induced cell migration was due to chemokine or cytokine signaling.

METHODS

To generate DC vaccines, DCs were harvested from bone marrow of wild type C57BL/6 mice and electroporated with OVA-mRNA. Human DCs were isolated from PBMCs. DCs were treated with sarcosine at 20mM. OT-I T cells were isolated from transgenic mice and injected intravenously into B16F10-OVA tumor bearing mice. Following T cell transfer, DC vaccines were injected intradermal. In vitro migration was analyzed via transwell migration assay. In vivo migration was evaluated by flow-cytometry and immunofluorescence microscopy. Gene expression in RNA was investigated in DCs via RT-PCR and Nanostring.

RESULTS

Sarcosine significantly increases human and murine DC migration in vitro. In vivo murine model, sarcosine-loaded DCs had significantly increased migration to both the lymph nodes and spleen after intradermal delivery. B16F10-OVA tumor bearing mice were treated with the sarcosine-loaded DC vaccines resulted in a significant survival advantage over control and naïve DC vaccines. Gene expression in RNA was investigated in DCs. CXCR2,CXCL3 and CXCL1 were found to be upregulated in sarcosine-loaded DCs. Further metabolic analysis demonstrated the upregulation of cyclooxygenase-1 and Pik3cg. In vitro DC migration in presence of CXCR2 neutralizing antibody showed sarcosine induced migration was abrogated by adding the CXCR2 neutralizing antibody in both human and murine DCs. Animals that treated with sarcosine-loaded DC showed significantly better tumor control compares to the animals receiving anti-CXCR2 antibody one hour before DC injection.

CONCLUSION

Sarcosine increases the migration of murine and human DCs via the CXC chemokine pathway. This platform can be utilized to improve existing DC vaccine strategies.
EXTH-22. ENHANCED DRUG DELIVERY AND CIRCULATION WITH THE NEURAPHERESIS™ SYSTEM FOR THE TREATMENT OF LEPTOMENINGEAL METASTASES
Authors: Marius Choiselle , Ripple Katelyn , de Castro George , Chen Yutong , Giamberadino Charles , Verbick Laura , McCabe Aaron , Fecci Peter , Lad Shivanand
Published: November 2019

Leptomeningeal Metastases, a severe late stage form of cancer progression in which malignant cells metastasize to the subarachnoid space (SAS) and leptomeninges, has a mean survival rate of 3–6 months with treatment. Standard of care intrathecal chemotherapy, delivered via an Ommaya reservoir, is limited by poor diffusion within the SAS and acute drug-related neurotoxicity. Neurapheresis™ therapy (NA) is a novel therapy that uses a dual lumen intrathecal catheter and extracorporeal filtration system to filter cerebrospinal fluid (CSF) in a closed-loop. We have previously demonstrated the ability of NA to decrease cancer cell burden in artificial CSF in vitro. Here, NA is shown to enhance chemotherapeutic drug circulation, delivered intraventricularly, throughout the SAS in vitro. NA was tested with a cranial-spinal model of the SAS that included ventricular, cervical and lumbar sampling sites. Drug distribution was tested by comparing the circulation of a 6mg, 3mL ventricular bolus injection of Methotrexate (MTX) in PBS over 48 hours with and without NA (2.0 mL/min flow rate). Ventricular, cervical, and lumbar samples were collected at t=0.5, 4, 8, 12, 24, and 48 hours following drug administration and analyzed by a MTX-specific enzyme-linked immunosorbent assay (ELISA). Compared to controls, NA demonstrated increased, faster distribution of MTX throughout the neuraxis, with an average increase in MTX concentration of 63.7% and 171.5% in the cervical and lumbar sites, respectively, across time points from 4 to 24 hours. The NA system also rapidly decreased the high, potentially neurotoxic concentration of MTX in the ventricles immediately following drug administration and out to 12 hours post-injection. Future in vivo and in vitro testing focuses on pharmacokinetics (PK) in both animals and an advanced 3D-printed human cranial-spinal model to further evaluate the ability of the NA system to enhance MTX distribution throughout the SAS, while simultaneously removing circulating tumor cells.
EXTH-34. IN VITRO TUMOR TREATING FIELDS (TTFIELDS) APPLIED PRIOR TO RADIATION ENHANCES THE RESPONSE TO RADIATION IN PATIENT-DERIVED GLIOBLASTOMA CELL LINES
Authors: Michelhaugh Sharon , Mittal Sandeep
Published: November 2019

Tumor treating fields are FDA-approved for treatment of newly-diagnosed and recurrent glioblastoma. Adding TTFields therapy to standard-of-care extended progression-free survival and overall survival in newly-diagnosed glioblastoma patients. In this study, cell lines generated from newly-diagnosed glioblastoma patients were treated in vitro with TTFields prior to irradiation to determine if the response to radiation would be altered. This study was approved by the WSU Institutional Review Board and written consent obtained from the patients. Single-cell suspensions generated from tumor tissues obtained from newly-diagnosed patients were cultured in DMEM/F12 media with 10% fetal bovine serum and gentamicin. Prior to TTFields initiation, cells were plated on plastic coverslips (5×104cells/coverslip) and incubated overnight. Then, TTFields were applied at 200 kHz with a field intensity of ~1.6 V/cm for 3 days. After TTFields application, cells were irradiated with 2, 4, or 6 Gy, or were untreated. After radiation delivery, cells were harvested and replated in a clonogenic assay. From each group, 3 coverslips were each replated in triplicate. After 3 days (3 doubling times), cells were stained with crystal violet and plates were scanned to determine cell counts. Treatment groups were compared to their control group with t-test. For both patient-derived GBM cell lines tested, TTFields prior to radiation decreased the number of crystal violet-stained cells in the clonogenic assay plates. In cell line 15–037, pretreatment with TTFields decreased cell counts by 16, 29, and 56% after 2, 4, or 6 Gy radiation, respectively, compared to the control cells with no TTFields pretreatment (p< 0.05). The response in 14-015S cells was less radiation dose-dependent, with the decrease in cell counts ranging from 33–47% control across the radiation doses (p< 0.05). These data suggest that the use of TTFields therapy prior to radiotherapy may enhance the response to radiotherapy in GBM patients.
EXTH-36. PI3K INHIBITION IN CONJUNCTION WITH THE KETOGENIC DIET REDUCES GROWTH AND NEUROINFLAMMATION IN PEDIATRIC HIGH-GRADE GLIOMA
Authors: Noch Evan , Yim Isaiah , Cantley Lewis
Published: November 2019

Pediatric high-grade glioma remains a poorly treatable disease with high mortality. Targeted therapies have gained interest in this disease, but efficacy is limited by therapeutic resistance, often because of tumor heterogeneity. Phosphoinositide 3-kinase (PI3K) inhibitors represent a strong drug class for pediatric glioma, but their use is associated with insulin feedback that reactivates the PI3K pathway and drives therapeutic resistance. Here, we target insulin feedback that is the primary mechanism of PI3K inhibitor-related therapeutic resistance in pediatric high-grade glioma using the ketogenic diet. We treated patient-derived pediatric high-grade glioma stem cells with vehicle or the pan-PI3K inhibitor, BKM-120, in conjunction with phenformin to decrease glucose utilization. These cells exhibited 65% less proliferation when exposed to BKM-120 and phenformin. We treated NOD scid gamma (NSG) mice containing patient-derived pediatric high-grade glioma xenografts with vehicle or BKM-120 on a regular or ketogenic diet to determine whether reducing insulin feedback increases BKM-120 efficacy. Mice with intracranial glioma xenografts survived longer when treated with BKM-120 on the ketogenic diet than with BKM-120 or the ketogenic diet alone. We measured pro-inflammatory cytokines in glioma cells treated with BKM-120 and phenformin in comparison to vehicle-treated cells to determine their effect on neuro-inflammation. We also applied conditioned medium from glioma cells treated with BKM-120 and phenformin to cortical neurons to measure oxidative stress. We found that phenformin reduced the production of pro-inflammatory cytokines, including TNF-alpha, IFN-gamma, IL-1beta, and IL-6, by BKM-120-treated glioma cells. Cortical neurons treated with conditioned medium from BKM-120- and phenformin-treated glioma cells exhibited less oxidative stress than those treated with BKM-120 alone. Our results demonstrate that lowering glucose utilization and insulin feedback increases efficacy of PI3K inhibition and decreases neuro-inflammation. By using the ketogenic diet to reduce systemic glucose levels, this strategy may enhance efficacy and reduce morbidity of PI3K inhibitors in this population.
EXTH-37. A NOVEL TRANSDUCER ARRAY LAYOUT FOR DELIVERING TUMOR TREATING FIELDS TO THE SPINE
Authors: Naveh Ariel , Yesharim Ofir , Bomzon Ze’ev
Published: November 2019

Tumor Treating Fields (TTFields) are an antimitotic technology utilising electric fields to disrupt mitosis in cancer cells. TTFields are currently approved by the FDA for the treatment of Glioblastoma Multiforme (GBM) and Malignant Pleural Mesothelioma (MPM). TTFields are delivered through 2 pairs of transducer arrays placed on the patient’s skin. Each pair delivers TTFields in a single direction, and the pairs are placed to provide perpendicular field. Preclinical studies show that 1V/cm is the clinical threshold for the treatment to be effective. Some types of cancers send metastases to the spinal cord and CSF, i.e. leptomeningeal disease. The purpose of this study was to find transducer array layouts that deliver TTFields to the spine at therapeutic intensities of above 1 V/cm. Computational simulations testing the delivery of TTFields to the spine were performed using the Sim4Life 4.0 (ZMT Zurich) computational platform, and the Duke 3.1 and Ella 3.0 (ITI’S, Zurich) realistic computational models of a male and female respectively. “Standard” layouts in which a pair of arrays are placed on the front and back of the patient and second pair on the lateral aspects of the patient failed to deliver TTFields at therapeutic intensities to the spinal cord. This is probably because the spinal cord is surrounded by the CSF and spine, which shunt the electric fields from reaching the spinal cord. However, field intensities above 1 V/cm were observed when delivering TTFields when both arrays were placed on the patients back, with a first array placed close to the neck, and second array placed towards the thighs. In this case, the spinal cord and surrounding CSF act as a conductive cable, directing the electric field along the spine. This novel layout opens the possibility for treating cancerous disease along the spine.
EXTH-41. A NANOPARTICLE-BASED CANCER-SELECTIVE GENE TRANSFER STRATEGY FOR LOCALIZED THERAPY OF MALIGNANT HIGH GRADE GLIOMAS
Authors: Rao Divya , Phal Ashish , Naga Varun , Negron Karina , Oh Yumin , Hanes Justin , Soo Suk Jung
Published: November 2019

Treatment for malignant high grade gliomas entails surgery, followed by chemotherapy and/or radiation. Despite the intensive care, there is a ~90% recurrence rate. This is attributed to suboptimal efficacy of treatments in tackling widespread cancer cells. We have previously developed nanoparticles that provide widespread therapeutic distribution both in healthy and tumor tissues, but are incapable of differentiating between them. This limitation applies to the current standard-of-care and state-of-the-art gene therapies. Here, we evaluate the efficacy of DNA nanoparticles carrying promoters that drive transgene expression specifically in tumor cells to achieve widespread yet cancer-selective gene transfer in high grade gliomas. To identify tumor-specific promoters, we used ELISA to confirm elevated expression of proteins previously reported to be upregulated in tumor tissue. We observed that expression of survivin in cancer cells was significantly greater than that of other cancer-rich proteins, exhibiting two orders of magnitude greater levels in rodent and human cancer cells compared to their respective healthy cells. Furthermore, the CMV promoter mediated similarly high expression in healthy cells, whereas the level achieved by the survivin promoter was significantly lower, if not negligible, suggesting its tumor specificity. Likewise, CMV-driven plasmids delivered into the brain by the nanoparticles mediated virtually identical volumetric distribution of transgene expression in both normal and tumor tissues in vivo. In contrast, nanoparticles carrying survivin-driven plasmids provided widespread transgene expression only in an orthotopically established tumor, but not healthy brain tissue. Additionally, we demonstrate therapeutic efficacy in an established brain tumor model using the DNA nanoparticles carrying survivin promoter-driven plasmids expressing a therapeutic protein. We identified survivin promoter as a lead TSP and confirmed its ability to mediate highly efficient and widespread but cancer-selective transgene expression with the aid of our nanoparticles uniquely designed to penetrate in healthy and tumor tissues.