bluuebunny/crossref_metadata_2025_split huggingface dataset:
EXTH-39. BENCH TO BEDSIDE NEURO-ONCOLOGY: ADVOCATING FOR A CLINICALLY RELEVANT STRATEGY
Authors: Zammar Samer , Madden Dennis , Schreck Karisa , Berens Michael , Dietrich Jorg , Glantz Michael 
Published: November 2019

Abstract

INTRODUCTION
Therapeutic successes in neuro-oncology have lagged dramatically behind exciting laboratory discoveries, and successful translation of promising laboratory findings into clinical practice is rare. We hypothesize that one important reason for this discordance is the use of very different paradigms for designing laboratory and clinical trials, and that utilizing clinically relevant procedures could improve laboratory study impact.

METHODS
We identified all pre-clinical neuro-oncology therapeutic trials published in four high-impact journals between 11/2018 and 4/2019, and assigned a level of evidence (LOE) to each study using the American Academy of Neurology evidence classification system. We also extracted details about statistical techniques, funding, and institutional setting.

RESULTS
Of the 26 articles identified, 85% had a LOE of IV (highest-I, lowest-IV) and 15% were class III. Factors contributing to the low LOE included lack of randomization (65%) or allocation concealment (100%), absence of masked assessment (96%), and no comparison of treatment and control groups with respect to prognostically relevant characteristics (92%). Effect size and confidence interval reporting, power calculation, correction for multiple hypothesis testing, and multivariate analysis were absent in 92%, 92%, 100%, 88%, and 92% of studies respectively. The “reverse” analysis (starting with successful human trials and analyzing existing pre-clinical support studies) showed significantly more high quality laboratory studies supporting “successful” compared to “unsuccessful” trials (p=0.04).

CONCLUSIONS
When rigorous human clinical trials criteria are applied to therapeutic laboratory studies, laboratory study LOE is uniformly poor. For laboratory research intended to inform clinical trial design and improve clinical outcomes, this situation dooms most basic science research to fail in the clinical arena. The steps required to solve this problem are challenging but addressable, and costs associated with the solution are dwarfed by the expense of early phase human trials which are destine to failure.
EXTH-44. INHIBITION OF MerTK ACTIVATES GLIOBLASTOMA-ASSOCIATED MACROPHAGES AND INDUCES TUMOR CELL DEATH IN GLIOMA MICROENVIRONMENT
Authors: Su Yu-Ting , Butler Madison , Hwang Lee , Maric Dragan , Earp Shelton , Terabe Masaki , Gilbert Mark , Wu Jing 
Published: November 2019

Abstract

BACKGROUND
Glioblastoma-associated macrophages and microglia (GAMs) are the predominant immune cells in the tumor microenvironment. Activation of MerTK, a receptor tyrosine kinase, triggers efferocytosis and polarizes GAMs to an immunosuppressive phenotype, promoting glioma growth. Our previous findings showed that UNC2371, a small-molecule inhibitor of MerTK, induced a less immunosuppressive phenotype of GAMs. Here, we investigate the role of MerTK inhibition on glioblastoma cells in the tumor microenvironment in vitro and in vivo.

METHODS
Cytotoxicity of UNC2371 in glioblastoma cells was determined by cell viability and colony formation assays. The protein expression of MerTK, AKT, and Erk were quantified by Western blotting in UNC2371-treated glioblastoma cells. A syngeneic GL261 mouse orthotopic glioblastoma model was used to evaluate the survival benefit of UNC2371 treatment. Fluorescent multiplex immunohistochemistry (IHC) was used to evaluate the expression of CD206, an anti-inflammatory marker on GAMs in murine brain tumor tissues.

RESULTS
UNC2371 inhibited GBM cell growth with an EC50 < 100 nM in both human U251 and mouse GL261 glioma cells, but not in GAMs. UNC2371-induced cell death and decreased cell proliferation were demonstrated by colony formation assays. UNC2371 decreased protein expression of phosphorylated MerTK, AKT, and Erk, which are essential for cell survival signaling, in U251 and GL261 cells. Furthermore, UNC2371 treatment prolonged survival in the mouse orthotopic GL261 glioblastoma model, suggesting that UNC2371 induces glioma cell death. A decreased of CD206+ GAMs was found in mice glioma tissues by fluorescent multiplex IHC, consistent with our previous findings in the in vitro cell-based assays. These data suggest that in addition to alleviate immunosuppression in the glioma microenvironment, UNC2371 directly inhibits GBM cell growth in vitro and in vivo.

CONCLUSION
Our findings suggest that UNC2371 has a therapeutic benefit via promoting GAM polarization towards proinflammatory status in the glioblastoma microenvironment and unexpectedly, inducing tumor cell death.
EXTH-51. GENETICALLY STABLE POLIOVIRUS VECTOR PLATFORM FOR DIPG IMMUNOTHERAPY
Authors: Gromeier Matthias , Mosaheb Mubeen , Dobrikova Elena , Brown Michael , Bigner Darell , Ashley David 
Published: November 2019

Abstract
Options for the immunotherapy of diffuse intrinsic pontine glioma (DIPG), due to its anatomical location and inherent therapy resistance, are limited. The histone 3.3(K27M) mutation in ~80% of such tumors offers a unique opportunity for immunotherapy intervention, as it defines a high affinity, HLA-A2-restricted tumor neoantigen that spontaneously elicits CD8+ T cell responses in DIPG patients. Immunizing against the H3.3(K27M) signature in the clinic has been challenging, as conventional approaches (i.e. peptide-conjugates administered with adjuvants) lack the costimulatory signals known to drive CD8+ effector T cell responses. Therefore, we built on a viral vector approach for engaging innate immune responses to virus infection specifically in antigen presenting cells. Viruses naturally engage innate immunity, induce antigen presentation, and mediate CD8 T cell priming against foreign antigens. Polioviruses can provide a context optimal for generating antigen-specific CD8 T cells, as they have natural tropism for dendritic cells, preeminent inducers of CD8 T cell immunity; elicit Th1-promoting inflammation; and lack interference with innate or adaptive immunity. However, notorious genetic instability and underlying neuropathogenicity has hampered poliovirus-based vector applications. We devised a strategy based on the polio:rhinovirus chimera PVSRIPO, devoid of viral neuropathogenicity after intracerebral inoculation in human subjects, for stable expression of exogenous antigens. PVSRIPO vectors infect, activate, and induce epitope presentation in DCs in vitro; recruit and activate DCs with Th1-dominant cytokine profiles at the injection site in vivo. They efficiently prime tumor antigen-specific CD8 T cells in vivo, induce CD8 T cell migration to the tumor site, delay tumor growth and enhance survival in syngeneic rodent tumor models. We are preparing a prototype PVSRIPO-derived vector delivering the H3.3(K27M) signature for clinical investigation.
EXTH-55. TEMOZOLOMIDE-RESISTANT GLIOMA CELLS ARE SENSITIVE TO CHLOROETHYLATING NITROSOUREA COMPOUNDS IN COMBINATION WITH ATR INHIBITORS
Authors: Jackson Christopher , Kalathil Aravind , Bindra Ranjit 
Published: November 2019

Abstract

BACKGROUND
Despite decades of research, nearly all patients with glioblastoma (GBM) face recurrent disease. Temozolomide (TMZ), the drug of choice for GBM, methylates guanine bases at the O6 position (O6meG). These lesions are normally repaired by O6meG-methyltransferase (MGMT). When MGMT is deficient (e.g. in the case of promoter hypermethylation), O6meG lesions generate mispairs with thymine and activate the mismatch repair system (MMR), which is thought to be critical for the cytotoxicity of TMZ. Numerous studies have established that acquired MMR deficiency is a common mechanism of TMZ resistance that emerges in recurrent GBM. However, reversion of MGMT-methylation status is not common in recurrent GBM. Recent work from our group demonstrated that TMZ synergizes with ATR inhibitors (ATRi’s) in MGMT-methylated GBM cells. The goal of this project was to identify the specific types of alkylating agents that synergize with ATRi’s in an MGMT-methylated, MMR-deficient molecular context.

RESULTS
We used GBM cell lines U251 and LN229, which are both MGMT-methylated and exquisitely sensitive to TMZ in combination with ATRi at baseline, and created MMR-deficient versions through stable knockdown of MSH2. We determined that MSH2 knockdown conferred remarkable resistance in U251 and LN229 to TMZ treatment in comparison to their respective MMR-proficient counterparts. In addition, we were unable to detect synergy between ATRi’s and TMZ in the setting of MSH2 knockdown. In contrast to TMZ, we found that treatment with chloroethyl nitrosourea (CNU) alkylating agents--including lomustine--with ATRi’s was extremely effective in killing MGMT-methylated, MMR-deficient GBM cells.

CONCLUSION
Here, we report an exquisite synergistic interaction between ATRi’s and CNU agents in MMR-deficient, MGMT-methylated GBM cells. Future work in the lab will examine the interaction of CNU and ATRi’s with radiation therapy (RT). Because ATRi’s are known radiosensitizers, we believe that novel combinations of ATRi’s, lomustine, and re-RT may have promise in recurrent GBM.
EXTH-60. CONVECTION-ENHANCED DELIVERY OF EZH2 INHIBITOR FOR THE TREATMENT OF DIFFUSE INTRINSIC PONTINE GLIOMA
Authors: Sasaki Takahiro , Katagi Hiroaki , Goldman Stewart , Hashizume Rintaro 
Published: November 2019

Abstract
Diffuse intrinsic pontine glioma (DIPG) is a fatal childhood brain tumor and the majority of patients with DIPG die within 2 years after initial diagnosis. Factors that contribute to the dismal prognosis of these patients include the infiltrative nature and anatomic location in an eloquent area of the brain, which prevents total surgical resection and the presence of the blood-brain barrier (BBB), which reduces the distribution of systemically administered agents. Convection-enhanced delivery (CED) is a direct infusion technique to deliver therapeutic agents into a target site in the brain and able to deliver a high concentration drug to the infusion site without systemic toxicities. EZH2, histone methyltransferase of polycomb repressive complex 2, is a potential therapeutic target in DIPG. The study aims to assess the efficacy of EZH2 inhibitor by CED against DIPG xenograft model. The biodistribution of EZH2 inhibitor was evaluated by high-performance liquid chromatography (HPLC). HPLC analysis showed that the concentrationof EZH2 inhibitor in the brainstem tumor was only 3.74% of blood concentration by systemic administration. We treated mice bearing human DIPG xenografts with EZH2-inhibitor using intraperitoneal or CED administration. Intracranial tumor growth was monitored by bioluminescence image and therapeutic response was evaluated by animal survival. CED of EZH2 inhibitor suppressed tumor growth and significantly extended animal survival in compared to intraperitoneal administration of EZH2 inhibitor (P=0.0475). Taken together, our results indicate that CED of EZH2 inhibitor would provide an alternative strategy for bypassing the BBB and increasing efficacy of EZH2 inhibitor for the treatment of DIPG.
GENE-07. INFLUENCE OF EPIGENETIC MODULATION OF THE T-CELL REGULATORS EXPRESSION ON GLIOBLASTOMAS BY HISTONE 3 LYSINE METHYLTRANSFERASE OR DEMETHYLASE ON THE PROGNOSIS OF THE GLIOBLASTOMA PATIENTS
Authors: Kim Mee-Seon , Sam Lee Young , Choel Kim Dae , Zoon Kim Young 
Published: November 2019

Abstract

PURPOSE
The primary aim of this study is to investigate the expression of the T cell stimulators and inhibitors as well as histone modifying enzymes in the glioblastoma cells. Based on the expression of these proteins, authors estimate the prognostic role in glioblastoma patients and also validate the known prognostic factors.

MATERIALS AND METHODS
Using 84 FFPE samples of glioblastoma in the pathologic archives at our institute, immunohistochemical staining for T cell stimulators (CD 27, CD 28, CD 137, OX40, ICOS), inhibitors (CTLA-4, PD-1, PD-L1, TIM3, CD200R), histone 3 lysine methyltransferase (MLL4, RIZ, EZH1, NSD2), and histone 3 lysine demethylase (KDM5c, JMJD1a, UTX, JMJD5).

RESULTS
Median values of the immunohistochemical staining for T cell stimulators and inhibitors were 16.3% of CD27, 10.4% of CD28, 47.5% of CD137, 52.9% of ICOS, 32.2% of OX40, 31.4% of CTLA-4, 7.2% of PD-1, 55.5% of PD-L1, 62.2% of TIM3, and 42.8% of CD200R. In multivariate analysis, increased expression of CD28 (p=0.042), CD137 (p=0.009), EZH1 (p=0.040), and decreased expression of CTLA-4 (p=0.003), PDL-1 (p=0.020) in glioblastoma cells were independently associated with longer OS as well as known prognostic factors such as young age, high KPS, wide extent of resection, PRA class, and methylated MGMT promoter. Interestingly, 42 of 43 samples (97.7%) with decreased PDL1 expression had the increased EZH1 expression, 31 of 33 samples (93.9%) with decreased CTLA4 expression had the increased RIZ expression, 25 of 26 samples (96.2%) with increased CD137 expression had the increased UTX expression, and 36 of 39 samples (92.3%) with increased CD28 expression had the increased JMJD1a expression, respectively.

CONCLUSION
The result of presenting study suggest that the regulators of T cell can be considered as independent prognostic factors in glioblastoma patients and the expression of these regulators can be controlled by unique histone 3 lysine methylation enzymes.
GENE-15. TARGETING OF EPENDYMOMA AS INFORMED BY ONCOGENIC 3D GENOME ORGANIZATION
Authors: Okonechnikov Konstantin , Hübner Jens-Martin , Chapman Owen , Chakraborty Abhijit , Bump Rosalind , Chandran Sahaana , Kraft Katerina , Acuna Hidalgo Rocio , Mundlos Stefan , Coufal Nicole , Levy Michael , Crawford John , Ay Ferhat , Mesirov Jill , Pajtler Kristian , Dixon Jesse , Pfister Stefan , Kool Marcel , Chavez Lukas 
Published: November 2019

Abstract
By profiling enhancers in primary ependymoma tumors, we have recently identified putative oncogenes, molecular targets, and functional pathways. Inhibition of selected targets diminished the proliferation of patient-derived neurospheres and increased survival in mouse models of ependymoma. While enhancers frequently regulate the nearest gene, unambiguous identification of enhancer target genes remains to be a challenge in the absence of chromosome conformation information. Consequently, we have now used HiC to map the 3-dimensional organization of tumor chromatin in the two most common and aggressive ependymoma subgroups: posterior fossa group A (PF-EPN-A) and supratentorial ependymomas with gene fusions involving the NF-κB subunit gene RELA (ST-EPN-RELA). By an integrative analysis of enhancer and gene expression in the context of the newly derived HiC data, we find that a large amount of the previously predicted enhancer target genes can be confirmed by physical interactions. Importantly, we also identify many new putative tumor-dependency genes activated by long-range promoter-enhancer interactions. Complementary to the analysis of gene-enhancer interactions, we have also leveraged the HiC data for resolving structural rearrangements underlying copy number alterations frequently observed in PF-EPN-A tumors. Especially copy number gains of the 1q arm of chromosome 1 are associated with poor survival. Our preliminary results reveal complex structural variants that underlie 1q gains, which lead to inter-chromosomal rearrangements and affect several genes that potentially contribute to poor survival. We now aim to test the relevance of the novel candidate tumor-dependency genes for tumor cell growth and proliferation in patient derived ependymoma models.
GENE-19. TARGETED SEQUENCING PANEL (TODAI ONCOPANEL) FOR VARIOUS TYPES OF BRAIN TUMORS
Authors: Takayanagi Shunsaku , Tanaka Shota , Miyawaki Satoru , Shin Masahiro , Nakatomi Hirofumi , Shinozaki-Ushiku Aya , Oseto Kumiko , Kohsaka Shinji , Oda Katutoshi , Aburatani Hiroyuki , Mano Hiroyuki , Saito Nobuhito 
Published: November 2019

Abstract

BACKGROUND
Todai OncoPanel (TOP) is a targeted sequencing panel newly invented by the University of Tokyo, which allows us to prospectively investigate on genomic abnormalities of multiple cancer-related genes. The objective of this study was to assess its role in molecular diagnosis as well as in patient treatment.

METHODS
Thirteen cases of brain tumors were analyzed: 10 gliomas and glioneural tumors, 2 meningiomas, and 1 intracranial sarcoma. DNA and RNA were obtained from tumor samples; DNA was obtained from peripheral blood as well. The TOP DNA panel analyzed point mutations, insertions, deletions, and copy number variations of 464 cancer-related genes. The TOP RNA panel detected fusions, exon skipping, and expression abnormalities of 463 genes.

RESULTS
In all cases of gliomas, the tumor content was abundantly high and the analysis was performed with sufficient depth. The IDH1/2 mutation status and chromosome 1p/19q status were completely consistent with those obtained by Sanger sequencing and microsatellite analysis. In benign brain tumors, the tumor content tended to be low. The number of gene mutations identified also tended to be low. In a case of glioneuronal tumor, FGFR2 mutation was recognized, but there was no clinical trials of FGFR inhibitors open in Japan yet.

DISCUSSION
TOP is useful as an aid for molecular diagnosis of gliomas. In spite of some targetable genetic abnormalities detected in the tested tumors, its efficacy may be limited by the scant availability of respective molecularly targeted agents.
GENE-21. ROLE OF POT1 MUTATION IN GLIOMA PROLIFERATION AND SEXUAL DIVERGENCE OF SURVIVAL
Authors: Jalali Ali , Yu Kwanha , Beechar Vivek , Mehra Deepika , Lozzi Brittney , Bondy Melissa , Deneen Benjamin 
Published: November 2019

Abstract
Germline POT1 mutations are associated with risk of several cancers including glioma. In The Cancer Genome Atlas, we found that the level of POT1 gene expression in tumors is associated with overall survival in IDH wild-type glioma independent of age and tumor grade (P=0.036). To assess if POT1 expression in a native mouse model of IDH wild-type glioma (referred to as C3 tumors) affects survival, we targeted both mouse POT1 orthologs (Pot1a/Pot1b) in C3 tumors using CRISPR/Cas9, generating C5 tumors. Interestingly, we noted a sexual divergence of survival, with female C5 mice dying faster than males (P=0.0034), whereas C3 mice show no sexual divergence in survival. To assess the genes and pathways underlying this divergence, we performed RNAseq profiling on C3 and C5 tumors and normalized the sex differences in the C5 profile for baseline sex differences in the C3 profile. Compared to males, female C5 tumors had lower enrichment of numerous gene sets related to immune surveillance. To specifically assess the effects of glioma-associated human POT1 variants, we expressed these variants in a mouse tumor sphere culture. We noted that expression of POT1-G95C variant increased the rate of sphere formation in vitro. In vivo expression of this variant in embryonic mouse brain during the gliogenic period increased the proliferative rate as assessed by BrdU uptake (P=0.008). These findings suggest a potential role for human POT1 variants in growth and proliferation of glial progenitor cells as well as glioma tumor cells. Additionally, the sexual divergence of survival in C5 tumors points to a differential interaction between POT1 loss and sex in regulation of immune response to these tumors.
GENE-24. DNA METHYLATION SIGNATURES DETECTED IN A SERUM-BASED LIQUID BIOPSY DISTINGUISH FUNCTIONAL AND INVASIVENESS FEATURES IN PITUITARY ADENOMAS
Authors: Wells Michael , Sarraf Sabedot Thais , Asmaro Karam , Mosella Maritza , Malta Tathiane , Nelson Kevin , Snyder James , deCarvalho Ana , Mukherjee Abir , Bahn Arti , Robin Adam , Rosenblum Mark , Mikkelsen Tom , Poisson Laila , Lee Ian , Walbert Tobias , Kalkanis Steven , Rock Jack , Noushmehr Houtan , Chitale Dhananjay , Castro Anavaleria 
Published: November 2019

Abstract
Pituitary tumors are the second most common CNS neoplasia (~15%). Despite mostly benign and slow-growing, they may be nonfunctioning and invade surrounding structures resulting in significant comorbidities. Currently, classification of PT according to their risk for aggressiveness is mainly based on invasiveness detected by imaging methods and histopathological features which requires surgically resected tumor. Being able to detect molecular markers associated with tumor subtypes and behavior pre-surgically using minimally invasive approaches (blood draw) is desirable in these tumors and may help to address current diagnostic and therapeutic challenges. In tissue specimens, distinct DNA methylation patterns distinguish PT according to their functional status but their role in invasiveness is still unclear. We hypothesized that profiling cell-free DNA (cfDNA) released by PT into the bloodstream allow the identification of epigenetic markers associated with relevant clinicopathological features. Genome-wide methylome profile of paired serum cfDNA (EPIC array) and tissue from 13 patients with pituitary macroadenomas (9 males; median age: 62; 9 Nonfunctioning/4 functioning, 6 invasive/7 noninvasive) and 3 controls serum (patients with epilepsy). Unsupervised analysis of the serum methylome from patients harboring PT was distinct from controls and other diseases (hypopituitarism, glioma and colorectal cancer) and supervised analysis (Wilcoxon Rank-sum Test) identified significant differentially methylated probes (DMP) that segregated PT from control serum specimens. Nonfunctioning and invasive-specific DMPs identified in the serum also defined functional, and less prominently invasive status, in the tissue of an independent cohort of PT. This is the first study to show the feasibility to profile the serum methylome from patients with PT using cfDNA. In addition, we identified unique methylation signatures that distinguished PT according to functional and invasiveness subtypes. These results underpin the potential role of methylation profile and liquid biopsy as a noninvasive approach to assess clinically relevant molecular features in the serum of patients harboring PT.