bluuebunny/crossref_metadata_2025_split huggingface dataset:
EXTH-08. DEVELOPMENT OF NOVEL HISTONE DEMETHYLASE INHIBITOR AGAINST DIPG
Authors: Suri Amreena , Venkatesan Srinivasan , Sasaki Takahiro , Ishi Yukitomo , Watanabe Jun , Abe Kouki , Ebetino Frank H , Frontier Alison J , Hashizume Rintaro 
Published: November 2022

Abstract

BACKGROUND
Diffuse intrinsic pontine glioma (DIPG) is one of most the devastating pediatric brain tumors, and virtually all patients die within two years after diagnosis. It has been shown that targeted inhibition of JMJD3 demethylase activity by GSK-J4 results in restored K27 methylation and a significant delay of tumor progression and prolonged animal survival in intracranial DIPG patient-derived xenograft (PDX) models. Because of its promising anti-tumor activities, GSK-J4 has been used to treat many kinds of tumors in preclinical models including leukemia, lymphoma, neuroblastoma, prostate, and gastric cancer, and DIPG; however, GSK-J4 is not yet in clinical development. The major challenge for GSK-J4 in clinical development is that GSK-J4 is a prodrug and is rapidly converted in vivo to the active drug GSK-J1, which has restricted cellular and brain permeability. Hypothesis: We hypothesize that development of a stable GSK- J1 analog that offers good cellular and brain transport is essential to improving in vivo efficacy and is required for clinical application of this class of compounds.

METHODS
We developed a novel alcohol derivative of GSK-J1, UR-8, as a lead anti-cancer agent through our screening and drug development activities.

RESULTS
UR-8 has demonstrated selective cytotoxic activity against human K27M DIPG cells in vitro and apparently transported the brain to a useful extent based on its in vivo bio-distribution and effectiveness.

CONCLUSION
UR-8 showed greater anti-tumor activity and survival benefit than that obtained by GSK-J4 treatment in intracranial DIPG PDX models.
EXTH-09. HSP90 INHIBITION AS A NOVEL THERAPY FOR DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG)
Authors: Sbergio Stefanie-Grace , Sheth Javal , Canty Laura , Pajovic Sanja , Vadivel Arun Anguraj , Carette Sheyenne , Siddaway Robert , Hawkins Cynthia 
Published: November 2022

Abstract
Diffuse intrinsic pontine glioma (DIPG) is an aggressive pediatric brain tumor. The mean age of onset is 7-9 years with a median survival of 9 months following diagnosis. Histone 3 (H3) mutations (H3K27M) have been identified in approximately 80% of patients, representing an intriguing target, but how to do this is unclear. To address this, we performed a synthetic lethality drug screen of over 2400 compounds on isogenic cells expressing H3K27M and empty vector. 37 drugs were synthetically lethal with H3K27M, including HSP90 inhibitors. In cancer, HSP90 has a higher isoelectric point which can be targeted specifically by PU-H71. Using PU-H71, HSP90 complexed with oncogenic clients can be inhibited to reduce tumor cell viability. We tested PU-H71 on primary patient derived DIPG lines demonstrating caspase-3/7 mediated cell death within 24 hours (n=3) and an IC50 of 100-200 nM (n=5) at 72 hours. HSP90 is a molecular chaperone that supports protein activation and localization; thus, its inhibition may allow simultaneous targeting of multiple oncogenic pathways. To determine which pathways are targeted in DIPG we used PU-H71-conjugated beads to pull-down HSP90 complexed with client proteins. LC-MS/MS characterization of the HSP90 interactome from three DIPG cell lines (SU-DIPG XVII, SU-DIPGXXV, SU-DIPG 50) identified 339 overlapping proteins including MAPK3, SMS, SRM, CTSP1, OAT, GMPS, and PYG. Pathway enrichment analysis highlighted roles in cell cycle regulation and metabolic processes. Treating DIPG with PU-H71 successfully reduced tumor cell viability but PU-H71 has poor brain penetration. To overcome this, a molecular isoform of PU-H71 has been developed, PU-HZ151, which will be used to test the in vivo efficacy of HSP90 inhibition for DIPG.
EXTH-10. TARGETING MITOCHONDRIAL ENERGETICS REVERSES THERAPEUTIC RESISTANCE IN PEDIATRIC DMG AND HGG
Authors: Reslink Matthew , Jane Esther , Premkumar Daniel , Gatesman Taylor , Wendell Stacy , Agnihotri Sameer , Pollack Ian 
Published: November 2022

Abstract
Diffuse midline gliomas (DMGs) and other high-grade gliomas (HGG) are the most commonly lethal intrinsic brain tumors of childhood. Accordingly, novel treatment approaches are needed that consider the heterogeneity of these tumors. Using an extensive pharmacological screen, we identified several two-drug combinations that were particularly effective against a range of DMG and HGG cell lines, the most active being the combination of the histone deacetylase inhibitor, panobinostat, and a proteasome inhibitor, marizomib, both in clinical trials, which synergistically induced tumor-specific apoptosis. However, at clinically achievable concentrations, a small population of resistant tumor cells survived and dominated, mimicking the clinical scenario, which prompted our development of drug resistance models as mechanistic tools. Resistance mechanisms were examined using RNA sequencing of drug-resistant versus -naïve cells. NMNAT2, a critical mediator of NAD synthesis, was overexpressed in DIPGs in the context of high baseline QPRT expression, suggesting a critical role of NAD synthesis and utilization pathways in resistance. Gene-set enrichment analysis suggested a key role for glycolytic pathways in the resistance phenotype. In support of this hypothesis, we observed increased levels of mitochondrial mass and NAD and ATP in resistant cells compared to drug-naïve cells, as well as upregulation of glycolytic intermediates by LC/MS. Conversely, inhibition of OXPHOS and glycolysis pathways resensitized resistant glioma cells to apoptosis in vitro. To test this hypothesis in vivo, mice were injected with drug-naïve or resistant DIPG-013 glioma cells and were exposed to an OXPHOS and glycolysis inhibitor, lonidamine. Lonidamine alone extended survival of naïve (18.6 + 1.4 d vs. 25 + 1.6 d, p=0.0003) and resistant (18.7 + 1 d vs. 62 + 1 d, p=0.0002) DIPG13p models (Log-Rank). This supports the application of metabolic therapy as a novel strategy for treating resistant MGs that has activity in a clinically relevant DIPG model. Supported by NIHS10OD023402, the DIPG/DMG Collaborative, the CNI, and Connor’s Cure.
EXTH-12. PRECLINICAL AND CASE STUDY EXAMINATION OF THE COMBINATION OF THE CLPP AGONIST ONC201 WITH THE PI3K/AKT INHIBITOR PAXALISIB FOR THE TREATMENT OF DIFFUSE MIDLINE GLIOMA
Authors: Jackson Evangeline , Duchatel Ryan , Persson Mika , Mannan Abdul , Yadavilli Sridevi , Parackal Sarah , Game Shaye , Chong Wai Chin , Jayasekara Samantha , Le Grand Marion , Kearney Padraic , Douglas Alicia , Findlay Izac , Staudt Dilana , Germon Zacary , Skerrett-Byrne David , Nixon Brett , Smith Nathan , Hulleman Esther , Day Bryan , McCowage Geoffrey , Alvaro Frank , Waszak Sebastian , Larsen Martin , Colino-Sanguino Yolanda , Valdes-Mora Fatima , Rakotomalala Andria , Meignan Samuel , Pasquier Eddy , Vitanza Nicholas , Nazarian Javad , Koschmann Carl , Cain Jason , Mueller Sabine , Dun Matthew 
Published: November 2022

Abstract
Diffuse midline gliomas (DMGs), including those of the pons (diffuse intrinsic pontine glioma - DIPG), are pediatric CNS tumors recognized as the most lethal of all children’s cancers. Palliative radiotherapy remains the only approved treatment, with survival just 9-11 months post-diagnosis. The brain-penetrant small molecule therapy, ONC201, shows preclinical and emerging efficacy in early-stage clinical trials. However, patients invariably develop resistance, with some patients and models completely refractory to treatment. Using a powerful combination of pharmacology, proteomics, genomics, epigenetics, in vitro and in vivo modeling, across ten international laboratories, we have uncovered mechanisms underpinning resistance to ONC201. We find ONC201 elicits antagonism of the Dopamine receptor D2 (DRD2), whilst also causing mitochondrial degradation through potent agonism of the mitochondrial protease CLPP. This drives proteolysis of the electron transport chain (ETC) proteins including Succinate dehydrogenase A (SDHA) and the critical mitochondrial tricarboxylic acid (TCA) cycle regulator, Isocitrate dehydrogenase 3B (IDH3B). Loss of TCA activity reduces α-ketoglutarate and inhibits lysine demethylation, increasing methylation of H3K4me3 and H3K27me3, thus, altering the epigenome of DIPG. Mitochondrial disruption elicited redox-activated RAS-PI3K/AKT signaling, counteracted using the PI3K/AKT inhibitor paxalisib. The combination of ONC201 and paxalisib synergistically extended survival of two aggressive DIPG PDX models (SU-DIPG-VI vehicle=73 vs. combination=100-days, p=0.0027; SF8626 vehicle=36 vs. combination=43-days, p=0.0002). Compassionate access to this combination (n=2 patients; immediately post-RT and following re-RT) resulted in dramatic reductions in tumor volume, extending overall survival for the patient at diagnosis and the patient at progression (e.g., MR axial diagnosis scan = 1554 mm2, following twelve months on the combination, current tumor volume = 464 mm2 (~70% reduction), patient remains in progression free survival, 15 months since diagnosis). The clinical utility of our preclinical data is currently under investigation in the PNOC022 clinical trial (NCT05009992).
EXTH-20. IDENTIFICATION OF EX VIVO THERAPEUTIC VULNERABILITIES IN DIFFUSE GLIOMAS USING A FUNCTIONAL GENOMICS APPROACH
Authors: Lin Wan-Hsin , Smadbeck James , Barrett Michael , Feathers Ryan , Dorsay Sadeghian , Johnson Sarah , Karagouga Giannoula , Harris Faye , Murphy Stephen , Quiñones-Hinojosa Alfredo , Kizilbash Sani , Burns Terry , Jaeckle Kurt , Mrugala Maciej , Bendok Bernard , Moniz-Garcia Diogo , Fortin-Ensign Shannon , Rosenfeld Steven , Ida Cristiane , Jentoft Mark , Salomao Marcela , Yang Lin , Emanuel Angela , Schaefer-Klein Janet , Mansfield Aaron , Borad Mitesh , Cheville John , Vasmatzis George , Anastasiadis Panos 
Published: November 2022

Abstract
Diffuse gliomas are aggressive brain tumors that lack effective therapies. Despite advances in the molecular characterization of gliomas, targeted treatments have failed to improve patient outcomes to date. Here, we employed a functional genomics approach to rapidly identify therapeutic vulnerabilities and provide a strategy to individualize patient treatment. Our process combined comprehensive genomic and transcriptomic tumor profiling, custom algorithms and visualization software for data integration, and preclinical 3-dimensional ex vivo models (mcancers) for drug screening to assess response to therapeutic agents targeting specific molecular alterations. A total of 32 cases, including 5 oligodendrogliomas (1 primary and 4 recurrent), 5 astrocytomas (1 primary and 4 recurrent), and 22 glioblastomas (5 primary and 17 recurrent), were included in the study. Immunohistochemistry and integrated genomics confirmed that mcancers maintain key molecular alterations, including mutations, chromosomal rearrangements and focal amplifications, cellularity, and heterogeneity, faithfully recapitulating the original tumor. A total of 119 single drugs and 183 combinations were tested, including a panel of 26-brain penetrant targeted agents (18 single drugs and 8 combinations) that was curated to target common glioma oncogenic pathways and was tested across all cases. A strong correlation was observed between therapeutic vulnerabilities of glioma mcancers to targeted agents (EGFR, MET, PDGFR, HDAC inhibitors, etc.) and clinical experience. Single agent activity of panel compounds in the ex vivo setting was generally poor, with only 35% mCancers exhibiting &gt; 70% growth inhibition at Cmax. In contrast, combination strategies, especially ones including epigenetic drugs, were significantly more effective (affecting 22 out of 32 mCancers), underscoring the molecular complexity of gliomas and the need for clinical trials testing combination treatments. Our data identified a number of novel combination treatments with significant efficacy across glioma subtypes and molecular profiles, suggesting that our functional genomics pipeline can guide treatment selection and inform clinical trial enrollment for gliomas.
EXTH-22. TARGETING A NEWLY DISCOVERED IMMUNE CHECKPOINT, SIGLEC-15, INCREASES ONCOLYTIC EFFICACY OF ZIKA VIRUS (ZIKV) IN GLIOBLASTOMA (GBM)
Authors: Kesarwani Ashwani , Bais Sachendra Singh , Nair Sharmila , De Costa Amanda Andrade , Hu Tong , Shi Pei-Yong , Diamond Michael S , Chheda Milan G 
Published: November 2022

Abstract
We are developing ZIKV as a therapy for GBM. We previously demonstrated ZIKV specifically kills GBM stem cells. Using GL261 and CT2A mouse models, ZIKV induces a CD8+ T-cell mediated anti-tumor response and leads to 65% and 40% long term survivors, respectively (0%-untreated controls). ZIKV treatment significantly increases the number of myeloid cells in the tumor microenvironment (with about 10,000 infiltrating macrophages per ZIKV-treated brain, 1,000 cells per untreated brain). We hypothesized that by targeting a myeloid immune checkpoint, we would further enhance efficacy. Siglec-15 is a newly described myeloid checkpoint, and anti-siglec-15 antibody is currently in clinical trial for patients with advanced or metastatic solid tumors (NCT03665285). While there was no effect of anti-siglec-15 treatment alone, we observed increased efficacy when combined with ZIKV (cure rate: GL261-70%, CT2A-60% with ZIKV+anti-siglec-15 antibody; GL261-20%, CT2A-0% with anti-siglec-15 antibody alone; GL261-30%, CT2A-25% ZIKV alone; GL261-0%, CT2A-0% without treatment). Since recurrence is a major problem, we performed re-challenge experiments in cured mice at 6 months. Mice previously treated with anti-siglec-15 antibody and ZIKV had 70% long-term survival, compared to 30% of age matched untreated controls. This supports our earlier findings that an immunological response after ZIKV engenders long-term, tumor-specific, immune surveillance. Lastly, we used Siglec-15 knockout mice to confirm our observations. After treating Siglec-15 knockout mice bearing CT2A tumors with ZIKV, 70% animals were cured. There was no significant difference in survival between CT2A-bearing Siglec-15 knockout mice without ZIKV treatment compared to CT2A-bearing wild type hosts. Taken together, our work suggests targeting putative myeloid suppressor cells, combined with oncolytic ZIKV and its ensuing anti-cancer stem cell and activated CD8+ T-cell effects, may be an effective tool in neuro-oncology. Targeting Siglec-15 may also enhance other oncolytic or cytotoxic therapies.
EXTH-23. BICISTRONIC CAR-T CELLS TARGETING EGFR AND IL13RΑ2 MITIGATE ANTIGENIC HETEROGENEITY IN GLIOMA
Authors: Li Nannan , Yin Yibo , Rodriguez Jesse , Logun Meghan , Zhan Logan , Zhang Jiasi , Binder Zev A , Lin Zhiguo 
Published: November 2022

Abstract
Chimeric antigen receptor (CAR)-T cells have had a significant effect in hematological diseases, with a recent study confirming that the cells can last for ten years in vivo. Unfortunately, to date, CAR-T cells have had little effect in solid tumors. One cause of the treatment difficulty is antigenic heterogeneity. Our experience with CAR-T cells in glioblastoma suggests that addressing antigenic heterogeneity may improve the clinical efficacy. Targeting the epidermal growth factor receptor (EGFR) and interleukin 13 receptor subunit alpha 2 (IL13Rα2) individually could lead to tumor control in the short term, but it will be marked by tumor recurrence through antigen loss or downregulation in the long term. This resistance mechanism can be inhibited by combinatorial targeting. To this end, we have designed a bicistronic construct that targets both EGFR and IL13Rα2 simultaneously, to decrease the potential of antigen escape and tumor recurrence. The bicistronic CAR-T cells employ an “OR” logic gate to modify the T cells and kill the tumor cells in vitro and in vivo, in order to retain effectiveness when one target antigen is lost but the second is still present. Our experimental results demonstrate that and validate the safety and possibility of clinical translation. In addition, the efficiency of transfecting T cells with the single bicistronic vector was higher than two single vectors on monovalent CARs. In summary, the bicistronic CAR-T structure is a promising strategy to address the clinical problem of targeting antigenic heterogeneity in solid tumors and potentially level the barriers for targeted T-cell therapy. Educational Objectives: After completion, participants will be able to explain the importance of antigenic heterogeneity in solid tumors in the context of tumor escape. Participants will also be able to identify a strategy to reducing the problem of antigen escape and tumor recurrence through the implementation of bicistronic CARs.
EXTH-24. FILAMENTOUS PHAGE AS A NANOTHERANOSTIC FOR THE DETECTION, IMAGING, AND TREATMENT OF GLIOMAS
Authors: Lam Fred , Tsedev Uyanga , Belcher Angela 
Published: November 2022

Abstract
Current standard of care treatment for gliomas includes maximal safe surgical resection followed by concurrent chemoradiation, however, the diffuse infiltrative nature of gliomas present certain challenges for neurosurgeons to clearly visualize tumor tissue under conventional white light during microsurgical resection. Fluorescence-guided surgical techniques have been recently introduced to help surgeons better visualize tumor tissue under the operating microscope. Fluorescent dyes conjugated to nanoscale materials that are functionalized with glioma-targeting peptide sequences, such as the 39 amino acid chlorotoxin (CTX) peptide sequence, have demonstrated clinical efficacy in recognizing microscopic tumor cells during surgeries. M13 bacteriophage (phage) are versatile, genetically tunable nanocarriers that have been recently adapted for use as theranostic platforms. Applying p3 capsid CTX fusion with a unique “inho” circular single-stranded DNA (cssDNA) gene packaging system, we produced miniature CTX inho (CTX-inho phage particles with a minimum length of 50 nm that can target intracranial orthotopic patient-derived glioblastoma tumors in the brains of mice. Systemically-administered indocyanine green-conjugated CTX-inho phage accumulated in brain tumors, facilitating short-wave infrared detection. Furthermore, we show that our inho phage can carry cssDNA that are transcriptionally active when delivered to GBM22 glioma cells in vitro. The ability to modulate the capsid display, surface loading, phage length, and cssDNA gene content makes the recombinant M13 phage particle an ideal nanotheranostic platform for neuro-oncological applications.
EXTH-25. EXPLOITING EPIGENETIC DYSREGULATION IN ISOCITRATE DEHYDROGENASE MUTANT GLIOMA VIA THE USE OF HISTONE DEACETYLASE INHIBITORS
Authors: Sears Thomas , Drumm Michael , Piunti Andrea , Horbinski Craig 
Published: November 2022

Abstract
Isocitrate dehydrogenase 1/2 mutations (IDHmut) define a unique subtype of glioma that exhibits profound epigenetic dysregulation through DNA and histone hypermethylation. Though IDHmutgliomas are less aggressive than their IDH wildtype (IDHwt) counterparts, these tumors are still incurable and are invariably fatal. New treatments are therefore needed. Histone deacetylase (HDAC) enzymes compose a class of epigenetic drug targets already used in the clinic to treat other malignancies, but their potential against gliomas, specifically IDHmutgliomas, have not been extensively studied. We previously showed that IDHwt gliomas are more sensitive than IDHwt gliomas to the cytotoxic and antiproliferative effects mediated by the FDA-approved HDAC inhibitor panobinostat, and that this sensitivity was associated with a greater increase in histone acetylation in IDHmut glioma cultures. Follow-up RNA-Seq showed that panobinostat more greatly affected gene expression in IDHmut glioma cells, with 1999 significant differentially expressed genes showing a 10% or greater change in gene expression in IDHmut cells compared to 388 genes for IDHwt counterparts. This included the known HDAC target and cell-cycle inhibitor CDKN1A, with panobinostat causing a 1.9-fold greater upregulation of CDKN1A in IDHmut cells than IDHwt cells (p= 0.045). In immunocompromised mice intracranially engrafted with IDHmut or IDHwt glioma, 15 mg/kg intraperitoneally-administered panobinostat was detectable after 6 hours within the intracerebral tumors via mass spectrometry at a concentration of 52.4 ng/g (150.1 nM), and extended the survival of IDHmut glioma-engrafted mice (Median: 4 days; Mean: 9.4 days), but not IDHwt glioma-engrafted mice (IDHmut: logrank p= 0.044; IDHwt: logrank p= 0.18). These results suggest that HDAC inhibition via panobinostat may be an effective therapy to treat IDHmutglioma patients. Ongoing studies, including ChIP-Seq, will determine specific sites of histone acetylation and HDACs that are responsible for the greater sensitivity of IDHmut gliomas to HDAC inhibition.
EXTH-28. INTRATUMORAL HETEROGENEITY OF THERAPEUTIC VULNERABILITIES ACROSS ENHANCING AND NON-ENHANCING TUMOR COMPONENTS OF GLIOBLASTOMA: A PARADIGM-SHIFTING PERSONALIZED MEDICINE APPROACH
Authors: Lin Wan-Hsin , Moniz-Garcia Diogo , Feathers Ryan , Brooks Mieu , Middlebrooks Erik , Kinsella Lindsey , Chaichana Kaisorn , Quiñones-Hinojosa Alfredo , Anastasiadis Panos 
Published: November 2022

Abstract
Glioblastoma (GBM) is the most aggressive adult brain tumor with no effective therapy. Despite advances on its molecular characterization, targeted therapeutics remain out of reach. This lack-of-progress is largely attributed to molecular and spatial heterogeneity and absence of clinically applicable models to guide patient care. Moreover, as standard surgical resection is aimed at contrast-enhancing (CE) tumor, the molecular landscape and treatment response of the remaining non-contrast enhancing (nCE) component is largely unknown despite its active role in tumor progression and local recurrence. Here, we aimed to identify the functional impact of tumor heterogeneity and to explore therapeutic vulnerabilities of both CE and nCE components. Four tumor regions (two CE and two nCE) from each of five GBM patients were collected under neuronavigation. The resulting tissue was subjected to generation of 3D tumor models (a brain tumor initiating-enriched cell line and a spheroid-based mcancer model) with comparable success in both CE and nCE samples. A panel of 25 brain penetrant drugs (alone and in combination) targeting GBM drivers (i.e. RTK/Ras/PI3K, RB/cell cycle, p53/apoptosis, DNA damage repair, transcription addiction) was developed and used to test for therapeutic vulnerabilities. From each tumor region, 4.5 ± 3.7 (average ± SD) different targeting strategies were identified exhibiting at least 70% growth inhibition at Cmax. Drug response heterogeneity was relatively rare, varied among cases, and was independent of tumor enhancement status. To our knowledge, this is the first study to systemically assess treatment response from both CE and nCE patient-derived GBM models. Ongoing studies include comprehensive genome and transcriptome profiling and pathway analysis from these different tumor regions. We postulate that interrogation of molecular landscapes and vulnerability profiles of both CE and nCE tumor regions, will enable us to personalize and prioritize effective targeted interventions for GBM treatment.