bluuebunny/crossref_metadata_2025_split huggingface dataset:
DIPG-02. LIN28B EXPRESSION IN DIFFUSE MIDLINE GLIOMA
Authors: Knowles Truman , An Shejuan , Huang Tina , Qi Jin , Saratsis Amanda 
Published: June 2024

Abstract

BACKGROUND
Diffuse midline glioma (DMG) is the most lethal of all childhood cancers. LIN28B is a RNA binding protein expressed in a variety of cancers, which suppresses the let-7 family of microRNAs, which in turn suppresses a plethora of oncogenes. However, the role of LIN28B in DMG has not yet been explored. Therefore, we sought to determine the pattern of expression and potential function of LIN28B in DMG using rare DMG cell lines.

METHODS
All studies were performed on DMG cell lines (n=6) and controls (normal human astrocytes n=1, human neural stem cells n=1). RNA-Seq was performed using single-read sequencing at 50bp on the Illumina NextSeq 500 Sequencing System. Cells were then treated with DMSO or the LIN28B inhibitor, LI71, and submitted to functional in vitro studies, as well as RNA-Seq and Western Blot analysis. Functional pathways analysis was subsequently performed on resulting gene expression values with Ingenuity Pathways Analysis (Qiagen).

RESULTS
Differential LIN28B expression was demonstrated across cell lines, with DMG cells expressing greater LIN28B gene and protein levels compared to controls. LIN28B inhibition with small molecule inhibitor LI71 resulted in decreased cell proliferation and migration, in vitro. A total of 946 differentially expressed genes were identified between treatment groups (FC&gt;2 or &lt;-2, p&lt;0.05). Functional pathways analysis of differentially expressed genes implicated Cancer and Neurological Disease as the top disease processes, with Cellular Movement as the top molecular process in cell lines expressing LIN28B. Further, inactivation of Myc signaling was implicated in cells treated with LI71.

CONCLUSIONS
Our data demonstrates increased LIN28B expression in DMG cell lines compared with controls, with oncogenic effects on cell proliferation and migration. Further investigation of the LIN28B-let7 signaling axis is warranted in order to further explore LIN28B as a novel therapeutic target in DMG.
DIPG-29. PHENOTYPIC SCREENS IDENTIFY GENETIC REGULATORS OF NANOPARTICLE DELIVERY IN DIFFUSE MIDLINE GLIOMAS
Authors: Tsai Jessica W , Coppola Marissa , Kenny-Serrano Julianna , Doench John G , Hammond Paula T , Bandopadhayay Pratiti , Straehla Joelle P 
Published: June 2024

Abstract

BACKGROUND
Diffuse midline gliomas (DMGs) are a universally fatal pediatric brain tumor with a median survival of 12 months. There is a dire need to develop novel treatment strategies for these patients. Nanomedicine harbors great potential to encapsulate cargoes across tissue barriers and selectively target cells of interest. To effectively utilize existing nanomedicines and develop design criteria for novel formulations, an improved understanding of nano-bio interactions within the context of disease and development is required.

METHODS
We harnessed a lentiviral all-in-one CRISPR/Cas9 knock-out library paired with fluorescence-activated cell sorting to probe the functional impact of 700 genes on the delivery of lipid-based nanoparticles to DMGs. Layer-by-layer electrostatic assembly was utilized to synthesize a library of liposomal nanoparticles with polymer surface coatings.

RESULTS
Two patient-derived neurosphere models of DMG were transduced with the pooled, barcoded all-in-one CRISPR/Cas9 library. Following selection, cells were incubated with nanoparticles for 1, 4, or 24 hours and dynamically sorted into populations based on nanoparticle affinity. Genomic DNA was isolated from sorted cells and subjected to next generation sequencing for barcode identification. The relative enrichment of each single guide RNA in each population was determined relative to matched controls. We found strong agreement between biologic replicates and both cell lines, and our phenotypic screens revealed strong genetic regulators of nanoparticle uptake. We identified formulation-dependent and independent regulators, as well as regulators that were time-dependent. The top target genes are currently being validated in DMG and human neural stem cell models.

CONCLUSIONS
In ongoing work, we are leveraging genetic and chemical inhibition to sensitize DMG cells to nanoparticle therapeutics. We plan to leverage our screening technique to develop novel combination therapy approaches that could be implemented across multiple administration routes to enhance the use of nanomedicine for DMG and other pediatric brain tumors.
DIPG-34. IDENTIFICATION OF CAR-T CELL ENHANCING COMPOUNDS USING HIGH THROUGHPUT SCREENING
Authors: Jones Amber B , Meehl Michaela , DeVries Rebekah , Shelat Anang , Krenciute Giedre 
Published: June 2024

Abstract

BACKGROUND
The infiltrative growth patterns and restrictiveness of the blood brain barrier greatly limit therapeutic options for children diagnosed with diffuse intrinsic pontine gliomas (DIPGs). However, clinical trials using chimeric antigen receptor (CAR)-T cells have shown promise in DIPG patients. Despite some success, the biological limitations plaguing CAR-T cells hinder their overall efficacy. We propose that leveraging chemical compounds in tandem with CAR-T cells may provide an increased therapeutic benefit against this lethal brain tumor. Our study is aimed at using high throughput screening of &gt;2,000 FDA approved and investigational compounds to identify candidates that enhance CAR-T cell mediated cytotoxicity of DIPGs.

METHODS
In an initial limited screen (32 compounds) used for optimization, compounds were serially diluted using the Echo 650 acoustic liquid handler. Subsequent co-culture conditions of renilla luciferase transduced DIPG007 tumor cells and clinically relevant firefly luciferase transduced CAR-T cells were plated at a 2:1 effector: target (E: T) ratio. In comparison to DMSO control, drug induced changes on cell viability were measured using cell-specific luciferase activity at 24 and 72 hours.

RESULTS
The limited screen revealed the BET bromodomain inhibitor, GSK-046, as an initial target based on its ability to increase CAR-T cell viability after 72 hours. Preliminary validation of these findings supports this CAR-T enhancing role of GSK-046 via MTS assays. We also identified nonlethal concentrations of GSK-046 for DIPG007 cells that could be further tested in combination with CAR-T cells to determine therapeutic synergy.

CONCLUSIONS
Our initial findings warrant further investigation into the combinatorial benefit of GSK-046 and CAR-T cells against DIPGs. Currently, we are optimizing and expanding our drug screen to identify additional compounds that may complement CAR-T cell therapy. Furthermore, we intend to validate the cytotoxic benefit of our prioritized combinations in additional in vitro and in vivo settings.
DIPG-45. TARGETING HYPERACETYLATION IN PEDIATRIC DIFFUSE MIDLINE GLIOMAS USING ONCOLYTIC ADENOVIRUSES
Authors: Parthasarathy Akhila , Garcia-Moure Marc , He Jiasen , Shin Dong Ho , Gillard Andrew G , Lopez-Rivas Andres , Hampton Lethan A , Fan Xuejun , Jiang Hong , Lang Frederick F , Alonso Marta M , Gomez-Manzano Candelaria , Fueyo Juan 
Published: June 2024

Abstract

BACKGROUND
H3K27-altered pediatric diffuse midline glioma (DMG) is a highly aggressive type of brain tumor with a 5-year survival rate of less than 2%. Conventional treatments are restricted to palliative radiation therapy. Therefore, effective treatments are urgently needed. Results from a recent phase I clinical trial for Diffuse Intrinsic Pontine Glioma showed that intratumoral administration of Delta-24-RGD oncolytic adenovirus in combination with radiation improves survival without unwanted toxicity. Based on the rationale that, during infection, the early viral protein E1A binds P300, we hypothesize that combining oncolytic adenoviruses with p300 inhibitors will induce a robust modification of the post-translational landscape of DMGs and increase the anti-cancer effect of the oncolytic virus.

METHODS
Studies on Delta-24-RGD infectivity and replication were performed in a panel of clinically significant DMG cells. Modification of the acetylation levels of acid-extracted histones after Delta-24-RGD was analyzed using Western blot. Cell Titer Blue was utilized to measure cell viability, and ZIP-synergy scores were calculated using SynergyFinder.

RESULTS
We observed a time-dependent reduction in H3K27ac in human DMG cells following Delta-24-RGD infection with an 89% reduction in H3K27ac at 48h post-infection. Delta-24-RGD treatment of DMG cells resulted in optimum viral infectivity and replication. Combining Delta-24-RGD with the p300 inhibitor C646 resulted in enhanced cell death in vitro. Using a panel of oncolytic viruses that induce differential enzymatic and binding functions of P300, we showed that Delta-24-RGD mediated alteration of P300 activity is required for hypoacetylation in DMGs. We characterized the in vivo dynamics of K27M-H3.1 and K27M-H3.3 DMG-derived tumors in the brain stem of syngeneic animal models. In vivo experiments are in progress to examine the combinatorial anti-glioma effect of Delta-24-RGD and P300 inhibitors.

CONCLUSION
Collectively, our studies provide a strong mechanistic rationale for combining oncolytic adenoviruses and p300 inhibitors and should propel the eventual clinical testing of this approach in DMG patients.
DIPG-49. SPATIAL TRANSCRIPTOMIC SEQUENCING OF A DIPG PATIENT TUMOUR RESOURCE
Authors: Kordowski Anja , Mulay Onkar , Harris Lachlan , Nguyen Quan H , Day Bryan W 
Published: June 2024

Abstract

BACKGROUND
Diffuse Intrinsic Pontine Glioma (DIPG), the most common subtype of Diffuse Midline Glioma (DMG), is a brainstem high-grade glioma arising in young children and always proves fatal. Major challenges include the disease’s intratumoural genetic and cellular heterogeneity as well as its diffusely invasive phenotype. Research of the last few years has highlighted that interactions between cancer cells, the nervous system and immune cells crucially contribute to tumour cell invasion and disease malignancy. Hence, a better understanding of cancer-promoting interactions is a key requirement to elucidate novel strategies for the treatment of this devastating disease.

METHOD
We performed spatial transcriptomic sequencing on 10 sequential tumour-infiltrated DIPG patient brainstem regions, using the 10x Genomics Visium platform.

RESULTS
Spatially-informed analysis and cell type clustering overall highlighted the molecular intratumoural heterogeneity present in the disease. We assessed cell cluster interactions as well as receptor-ligand (RL) pairing, illustrating communication between neuronal, immune cell and tumour clusters. We further determined respective RL pairs involved in such. To address the question whether invasive edges genetically differ from the tumour core, we evaluated genes that are significantly correlated with distal brainstem regions compared to tumour proximal sites. Results revealed gene signatures that are highly associated with neuronal signalling and communication, validating previous findings emphasising the importance of neuron-to-glioma interactions driving DIPG disease progression.

CONCLUSION
DIPG is a lethal paediatric brainstem glioma for which more durable therapeutic modalities remain to be found. In-depth analysis of this disease is often hampered due to the lack of patient tissue suitable for laboratory studies. Our patient autopsy specimen, spanning the entire tumour-infiltrated brainstem provided a platform to study this aggressive disease in a spatio-temporal manner. This analysis elucidates how DIPG is driven by the tumour microenvironment, including associated receptor-ligand interactions. This has the potential to ultimately discover new treatment targets.
DIPG-50. TARGETING VULNERABILITIES IN PAEDIATRIC DIFFUSE MIDLINE GLIOMAS: LEVERAGING PLK1 INHIBITION TO EXPLOIT RAS/PI3K PATHWAY DEPENDENCY
Authors: Hayden Elisha , Dolman Emmy M , Upton Dannielle H , Franshaw Laura , Liu Jie , Nguyen Hieu , Tsoli Maria , Guo Xinyi , Mayoh Chelsea , Rayner Benjamin S , Ziegler David S 
Published: June 2024

Abstract

BACKGROUND
Diffuse Midline Gliomas (DMGs), characterised by prevalent H3K27M mutations, exhibit epigenetic modifications that drive a proliferative state resistant to conventional therapies. The interplay of the cell cycle with PI3K and RAS/MYC growth signalling pathways, pivotal in the context of the H3K27M mutation, is yet to be fully understood. The aim of this study was to assess the efficacy of the inhibition of Polo-like kinase 1 (PLK1), a critical regulator of mitosis and cell cycle progression, identify mechanisms of action, and to develop effective combination strategies against DMG.

METHODS AND RESULTS
PLK1 inhibition demonstrated significant anti-tumour activities both in vitro and within aggressive in vivo orthotopic DMG models, notably doubling the median survival of mice bearing tumours. High-throughput RNA-seq analysis of DMG samples particularly sensitive to PLK1 inhibition, revealed a distinct pattern of negative enrichment in ribosomal genes, indicating a marked reduction in ribosomal function-associated gene expression. This alteration suggests a potential for innovative drug combination strategies targeting the PI3K/mTOR and RAS/MYC pathways, crucial for ribosomal and RNA processing. Subsequently, our in vitro drug sensitivity assays demonstrated that PLK1 inhibition in combination with PI3K/mTOR and MEK inhibitors, exhibit strong drug synergies, evidenced by high Bliss synergy scores.

CONCLUSIONS
Our findings underscore the efficacy of simultaneous targeting of PI3K/mTOR and RAS/MYC pathways with PLK1 inhibition as an attractive strategy to mitigate DMG tumorigenesis. Furthermore this research not only sheds light on the crucial interplay between cell cycle and signalling pathways in DMG but also facilitates novel intervention strategies for a range of other paediatric CNS malignancies with similar characteristic molecular drivers.
DIPG-69. IN-VITRO DETERMINATION OF 5-AMINOLEVULINIC-ACID-TREATMENT EFFICACY IN PATIENT-DERIVED DIPG MODELS
Authors: Stano Martin , Kritzer Bettina , Hierlemann Andreas , Nazarian Javad , Modena Mario Matteo 
Published: June 2024

Abstract

BACKGROUND
Diffuse Intrinsic Pontine Glioma (DIPG) presents a significant clinical challenge due to its inoperable nature and poor response to current treatments. Sonodynamic Therapy (SDT) is a non-invasive therapy that combines low-intensity ultrasound stimulation with a sonosensitizing agent. 5-Aminolevulinic Acid (5-ALA) as a sonosensitizer has yielded positive outcomes in in-vivo glioblastoma models, and a clinical trial (NCT05123534) for DIPG patients is currently ongoing. 5-ALA is a precursor of Protoporphyrin IX (PpIX), which preferentially accumulates in cancer cells and generates cytotoxic reactive oxygen species upon activation by ultrasound or light. Our work is aimed at investigating the accumulation of PpIX in in-vitro DIPG patient-derived cell models to predict the efficacy of 5-ALA SDT treatment.

METHODS
Patient derived DIPG cell lines (H3K27M, P53 mutant and wild type) were used to create three-dimensional spheroids. The spheroids were dosed with 5-ALA for 4 hours, and PpIX accumulation was quantified by measuring its fluorescence intensity within the cells. The spheroids were then exposed to controlled light stimulation as an in-vitro proxy for SDT.

RESULTS
We confirmed the uptake of 5-ALA and subsequent PpIX accumulation in all patient-derived DIPG spheroids. Light exposure of 5-ALA treated DIPG spheroids resulted in reduced viability of the tumor models, while 5-ALA itself did not show cytotoxic effects. The extent of PpIX accumulation and cytotoxicity upon PpIX light activation varied among DIPG models with higher sensitivity of p53 wild type cells. Further studies incorporating a larger number of DMG cells with p53 alterations are underway.

CONCLUSIONS
These findings indicate that SDT using 5-ALA as sonosensitizer may offer clinical benefits for treatment of DIPG, however treatment efficacy could vary considerably between patients. In vitro evaluation of PpIX accumulation and sensitivity to activation could potentially provide a means to stratify patients and to identify those most likely to benefit from 5-ALA-mediated SDT.
DIPG-89. ENHANCEMENT OF BLOOD-BRAIN BARRIER PENETRATION AND TUMOR TARGETED DRUG DELIVERY FOR DMG USING A P-SELECTIN TARGETED NANOMEDICINE APPROACH
Authors: Li Bryan K , Vaynshteyn Jake , Tylawsky Daniel , Vogt Kristen , Raziuddin Raashed , Ge Yi , Heller Daniel A , Becher Oren , Raju G Praveen 
Published: June 2024

Abstract
The blood-brain barrier (BBB) is one of the greatest barriers for the effective treatment of brain tumors, including H3K27-altered diffuse midline glioma (DMG), a near universally fatal childhood brain cancer. The BBB typically requires drugs to be given at maximally tolerated doses that are limited by systemic toxicities, particularly in settings of combination therapy. We have developed a clinically compatible fucoidan nanoparticle (Fi-NP) that homes to P-selectin on tumor vasculature after low-dose radiation (RT) to breach the BBB through an active caveolin-1-dependent mechanism and deliver several classes of targeted therapies. In non-CNS cancer xenograft models and a transgenic mouse model of SHH-driven medulloblastoma with an intact BBB, this approach improved survival while eliminating on-target systemic toxicities. We have now applied this approach to both brainstem and non-brainstem RCAS-TVA mouse models of DMG with an intact BBB. Specifically, we have found that DMG tumor vasculature expresses P-selectin, and that a single low-dose 2 Gy fraction of ionizing radiation further enhances it in a time-dependent manner up to 24 hours post-treatment. Importantly, we have also found that this P-selectin targeted drug delivery approach facilitates DMG tumor localization of Fi-NP encapsulated EZH2 inhibitor tazemetostat (EPZ-6438) as well as larger macromolecules including the PROTAC BET degrader dBET6, two promising targeted therapies for DMG limited by extremely poor BBB-penetration, while sparing drug delivery to non-tumor healthy brain regions. Work to measure PK, biodistribution, survival benefit, and drug target inhibition is ongoing. Our findings will provide the foundation for this P-selectin targeted Fi-NP approach to be evaluated in clinical trials for children with this lethal cancer.
TRLS-14. PNOC022 REPORT: A COMBINATION THERAPY TRIAL USING AN ADAPTIVE PLATFORM DESIGN FOR PATIENTS WITH DIFFUSE MIDLINE GLIOMA AT INITIAL DIAGNOSIS, POST-RADIATION THERAPY, OR PROGRESSION
Authors: Kline Cassie , Franson Andrea , Banerjee Anuradha , Reddy Alyssa T , Raber Shannon , Hoffman Carly , Minturn Jane , van der Lugt Jasper , de Vos-Kerkhof Evelien , van Vuurden Dannis , Gerber Nicolas , Stucklin Ana S Guerreiro , Kilburn Lindsay , Elster Jennifer , Whipple Nicholas , Cohen Kenneth , Oren Michal Yalon , Gardner Sharon , Cluster Andrew , Chi Susan , Landi Daniel , McCowage Geoffrey , Vo Josh , Resnick Adam , Phillips Joanna , Bhatia Aashim , George Elizabeth , Vossough Arastoo , Nabavizadeh Ali , Braunstein Steve , Gupta Nalin , Prados Michael , Waszak Sebastian , Long-Boyle Janel , Molinaro Annette , Dun Matthew , Koschmann Carl , Nazarian Javad , Mueller Sabine 
Published: June 2024

Abstract

BACKGROUND
Children with diffuse midline glioma (DMG) face dismal prognoses. PNOC DMG-ACT (DMG-Adaptive Combination Trial, PNOC022) is an open-label, international trial investigating the efficacy of combination therapies for patients with DMG. We present an early report on Cohorts 1-3, treated with ONC201, an orally available ClpP agonist, and paxalisib, a dual PI3K-mTOR inhibitor.

METHODS
Patients aged 2-39 years enrolled pre-radiation (Cohort 1), 4-14 weeks post-radiation (Cohort 2), or at progression (Cohort 3). Patients were randomized to receive ONC201 or paxalisib prior to surgery when biopsy was indicated and/or in combination with radiation when radiation was indicated. Those not planned for biopsy were required to submit archival tissue. All received maintenance therapy with weekly ONC201 (weight based adult equivalent of 625 mg) and daily paxalisib (27 mg/m2). Plasma and CSF samples for pharmacokinetics (PK) and biologic correlates were collected.

RESULTS
Between November 2021 and September 2023, 132 patients met critera for study therapy (Cohort 1=33; Cohort 2=69; Cohort 3=30; median age 9 years [range 2-37], n=73 female [55%]; n=86 pontine [65%]). Median overall survival (OS) from diagnosis is 13.2 months in Cohort 1 (lower 95% CI 11.1) and 15.8 months in Cohort 2 (lower 95% CI 13.9). Median OS from progression is 8.8 months in Cohort 3 (lower 95% CI 8.6). Most common non-hematologic grade 3 and above treatment-related adverse events (TRAE) were maculopapular rash (n=12); mucositis (n=8); colitis and hyperglycemia (n=7). Most common serious TRAEs were colitis (n=7) and hyperglycemia (n=6). We have collected 169 CSF samples and &gt;600 plasma samples for ctDNA. Cohort 2 PK from CSF and plasma and CSF metabolomics and somatic mutation landscapes are being finalized.

CONCLUSIONS
We will present somatic mutation profiles, PK analysis, ctDNA, and metabolic signatures from the CSF in association with toxicity, survival, and tumor response via central imaging review.
ETMR-02. CNS EMBRYONAL TUMOR WITH BRD4–LEUTX FUSION POTENTIAL NEW MOLECULAR SUBTYPE OF EMBRYONAL TUMORS IN THE FUTURE WHO CLASSIFICATION OF TUMORS OF THE CENTRAL NERVOUS SYSTEM
Authors: Mobarak Nahla Aly , Banyan Ayman Al , Alyamnai Basma , Shakweer Wafa Al , Al-Dandan Sadeq , Alharbi Musa 
Published: June 2024

Abstract

INTRODUCTION
Central Nervous System (CNS) embryonal tumors previously called Primitive neuroectodermal tumors of the CNS (CNS-PNETs) are highly malignant tumors that predominantly affect Yonge children. CNS World Health Organization (WHO) 2021classification includes new embryonal tumor subtypes: CNS neuroblastoma, FOXR2-activated, CNS tumor with BCOR internal tandem duplication (ITD), and cribriform neuroepithelial tumor CRINET.CNS-embryonal tumors which cannot be classified into a specific subgroup, considered as ‘‘CNS embryonal tumors, NOS.’’

METHOD
We report a 2-year girl previously healthy presented with 2 weeks HX of vomiting, progressive lower limb weakness, and nystagmus. Radiological diagnosis was suggestive of metastatic ATRT with Brain and spine MRI showed a large left interventricular tumor (10.2 x 7.7 x 7.6 cm) centered in the posterior horn of the left lateral ventricle with extensive intracranial and spinal leptomeningeal CSF seeding metastasis she had Partial tumor resection LT-sided external ventricular drain EVD Insertion The tumor showed very aggressive behavior with rapid tumor recurrence/progression post-surgical resection the patient was treated with Palliative chemotherapy due to clinical and neurological deterioration the patient and died 2 months after diagnosis.

RESULT
Pathological examination showed Embryonal tumor (WHO Grade 4) with Medulloblastoma-like cells Immunohistochemistry: Synaptophysin: Positive Beta-catenin, P53: Negative and INI-1: Retained. NGS molecular testing was positive for BRD4–LEUTX fusion. Tumor DNA- -methylation profiling (DKFZ CNS v12.5) confirmed the diagnosis “CNS embryonal tumor with BRD4–LEUTX fusion” This rare very aggressive/uncurable tumor may show pathological features similarities with Medulloblastoma. Also, BRD4–LEUTX fusion was reported in pediatric epithelioid malignant peripheral nerve sheath tumor and an alveolar rhabdomyosarcoma

CONCLUSION
CNS tumor with BRD4– LEUTX fusion” A rare tumor has been described in the literatures in infant and young children and may be integrated in the CNS WHO classification as a new highly aggressive subgroup of CNS embryonal tumor.