bluuebunny/crossref_metadata_2025_split huggingface dataset:
DIPG-38. ADDITION OF MULTIMODAL IMMUNOTHERAPY TO COMBINATION TREATMENT STRATEGIES FOR CHILDREN WITH DIPG: FINAL RESULTS OF A COHORT OF CHILDREN
Authors: Van Gool Stefaan , Makalowski Jennifer , Bonner Erin R , Feyen Oliver , Domogalla Matthias , Prix Lothar , Schirrmacher Volker , Nazarian Javad , Stücker Wilfried 
Published: December 2020

Abstract
The prognosis of children with Diffuse Intrinsic Pontine Glioma (DIPG) remains dismal in spite of radio- and chemotherapy or therapies based on molecular biology diagnostics. Immunotherapy is a powerful and promising approach for improving the overall survival (OS). A retrospective analysis for feasibility, immune responsiveness and OS was performed on 41 children treated in compassionate use with Newcastle Disease Virus, hyperthermia and autologous dendritic cell vaccines as part of an individualized combined treatment approach for DIPG patients at diagnosis (n=28), or at time of progression (n=13). All except one patient had reduced values of at least one immune test before starting immunotherapy. In all patients at least one PanTum Detect test was outside the normal range. Ten patients had PDL1 mRNA expression in circulating tumor cells at diagnosis. Multimodal immunotherapy was feasible as scheduled, until progression, in all patients without major toxicity. When immunotherapy was part of primary treatment, median PFS and OS were 8.4m and 14.4m respectively with a 2-year OS of 10.7%. When immunotherapy was given at the time of progression, median PFS and OS calculated from diagnosis were 6.5m and 9.1m respectively. Th1 shift and rise in PanTum Detect test scores were linked with longer OS. Multimodal immunotherapy is feasible without major toxicity, and its value as part of a combination treatment for primary diagnosed DIPG should be elaborated in clinical trials.
DIPG-42. TOWARD MULTIMODALITY THERAPY FOR DIPG/DMG: DEVELOPMENT AND INVESTIGATION OF CRANIOSPINAL IRRADIATION AND CONVECTION-ENHANCED DELIVERY PDX MODELS
Authors: Knox Aaron J , Gilani Ahmed , van Court Benjamin , Oweida Ayman , Flannery Patrick , DeSisto John , Lemma Rakeb , Chatwin Hannah , Gamboni Fabia , Brown Benjamin , Serkova Natalie , Vibhakar Rajeev , Dorris Kathleen , Wempe Michael , Reisz Julie A , Karam Sana D , Green Adam L 
Published: December 2020

Abstract

BACKGROUND
Diffuse intrinsic pontine glioma (DIPG) and diffuse midline glioma (DMG) are metastatic diseases, as demonstrated by early convection-enhanced delivery (CED) clinical trials in which prolonged local tumor control can sometimes be achieved, but fatal disseminated disease then develops. We hypothesize that improvements in treatment of both focal disease and the entire neuraxis are necessary for long-term survival, and patient-derived xenograft (PDX) models can help advance these efforts.

METHODS
We used a BT245 murine orthotopic DIPG PDX model for this work. We developed a protocol and specialized platform to deliver craniospinal irradiation (CSI) with a pontine boost. We separately compared intratumoral drug concentration by CED and intraperitoneal delivery. In our CED model, mice receive gemcitabine 60 ug x1 in 15 ul at 0.5 ul/minute through a stepped catheter design with silica tubing extending 2mm beyond a 27G needle.

RESULTS
Mice receiving CSI (4 Gy x2d) plus boost (4 Gy x2d) showed minimal spinal and brain leptomeningeal metastatic disease by bioluminescence, MRI, and pathology compared to mice receiving radiation to the pons only (4 Gy x4d) or no radiation. CED achieved an intratumoral gemcitabine concentration 50-fold greater than intraperitoneal dosing when controlled for dose.

CONCLUSIONS
In a DIPG PDX model, CSI+boost minimizes tumor dissemination compared to focal radiation, and CED achieves clinically significant improvements in intratumoral chemotherapy concentration compared to systemic delivery. Adding these modalities to current treatment could improve both focal and metastatic tumor control, leading to meaningful improvements in survival.
DIPG-43. CAN WE REPROGRAM DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG)? EXPLORING THE ROLE OF DISTALLESS/DLX HOMEOBOX GENE REGULATION OF OLIGODENDROGLIAL PROGENITOR CELLS (OPC) IN THE DEVELOPING VERTEBRATE NERVOUS SYSTEM
Authors: Nevin Mikaela , Gallego Janine , Song Xiaohua , Jiang Qiang , Underhill Alan , Godbout Roseline , Becher Oren , Eisenstat David 
Published: December 2020

Abstract

BACKGROUND
The identification of H3.3/H3.1K27M in most DIPG has changed our understanding of this disease. H3K27M mutations usually demonstrate global loss of H3K27 trimethylation (me3) with gain of H3K27 acetylation (ac). Single cell RNAseq has identified the putative cell of origin as oligodendroglial progenitor cells (OPC). The distalless gene family is necessary for the differentiation and tangential migration of committed neural progenitors to become GABAergic interneurons. Dlx1/Dlx2 double knockout (DKO) cells from the ganglionic eminences (GE) transplanted into a wild-type environment become oligodendrocytes.

RESULTS
We identified DLX2 occupancy of early (Olig2, Nkx2.2) and late (Myt1, Plp1) genes required for OPC differentiation in vivo and confirmed direct DLX2 protein-promoter DNA binding in vitro. Co-expression of Dlx2 with target sequences reduced reporter gene expression in vitro. There was increased expression of OLIG2, NKX2.2 and PLP-1 expression in vivo, consistent with de-repression in the absence of Dlx1/Dlx2 function. Transient over-expression of a Dlx2-GFP construct into murine DIPG cells from a GEMM that develops DIPG resulted in significant increases in expression of Gad isoforms with concomitant decreases in Olig2 and Nkx2.2. Dlx2-transfected mDIPG cells also demonstrated reduced migration, invasion and colony formation in vitro. Of significance, there was global restoration of H3K27me3 with corresponding loss of H3K27ac expression in transfected cells compared to controls.

CONCLUSIONS
DLX2 promotes GABAergic differentiation and migration while concomitantly repressing OPC differentiation in vivo. Developmental reprogramming of mDIPG cells by DLX2 demonstrates the potential role for directed differentiation strategies towards improving patient outcomes for this devastating pediatric cancer.
DIPG-47. HISTONE MUTATIONS ENHANCE RAS MEDIATED ERK5 GROWTH SIGNALING IN DIFFUSE MIDLINE GLIOMAS
Authors: Stanton Ann-Catherine , Koncar Robert , Golbourn Brian , Dey Brittany , Agrawal Nishant , Mack Stephen , Pollack Ian , Agnihotri Sameer 
Published: December 2020

Abstract
Diffuse midline gliomas (DMGs) are incurable brain tumors with an aggressive onset. Apart from irradiation, there are currently no effective therapies available for patients with DMG, who have a median survival time of less than one year. Most DMG cells harbor mutations in genes encoding histone H3 (H3K27M) proteins, resulting in a global reduction of H3K27 trimethylation and activation of oncogenic signaling pathways. Here we show that the H3K27M mutations contribute to RAS pathway signaling, which is augmented by additional RAS activators including PDGFRA. H3K27M mutation led to increased expression of receptor tyrosine kinases (RTK). A RAS pathway functional screen identified ERK5, but not ERK1/2, as a RAS pathway effector important for DMG growth. Suppression of ERK5 decreased DMG cell proliferation and induced apoptosis in vitro and in vivo. In addition, depletion or inhibition of ERK5 significantly increased survival of mice intracranially engrafted with DMG cells. Mechanistically, ERK5 directly stabilized the proto-oncogene MYC at the protein level. Additionally, persistent ERK5 depletion does not result in complete growth inhibition and therefore we set out to determine potential adaptation or resistance mechanisms in response to ERK5 loss. Using RNA-sequencing and Immunoprecipitation (IP) mass spectrometry (IP-MS), we have identified several positive and negative feedbacks involved in ERK5 that are also targetable. These findings identify the H3K27M mutation as an enhancer of RAS activation in DMG with ERK5 and ERK5 regulated networks immediately actionable pathways.
DIPG-50. A NOVEL ORTHOTOPIC PATIENT-DERIVED XENOGRAFT MODEL OF RADIATION-INDUCED GLIOMA
Authors: Whitehouse Jacqueline , Howlett Meegan , Stanley Jason , Hii Hilary , Valvi Santosh , White Christine , Mayoh Chelsea , Wong Marie , Strowger Brooke , Dyke Jason , Cowley Mark , Gottardo Nicholas , Endersby Raelene 
Published: December 2020

Abstract
Diffuse midline glioma (DMG) can arise as a primary tumour but also as a consequence of radiation therapy (RT) in survivors of other paediatric brain tumours. Radiation-associated gliomas are molecularly distinct from primary gliomas and have poorer overall survival. We report a case of radiation-associated DMG following treatment for medulloblastoma, and the development of a matched patient-derived xenograft (PDX) model. A four-year-old boy diagnosed with medulloblastoma was treated with surgical resection, RT and chemotherapy (COG:CCG-99701-Arm B). Eleven years post-diagnosis, the patient relapsed with radiation-associated DMG, participated in a Phase I clinical trial (COG:ACNS0927), and passed away eight months later. Tumour tissue collected at autopsy was intracranially implanted into immunodeficient mice and serially transplanted in vivo. Immunohistochemistry demonstrated both the primary DMG and PDXs expressed PDGFR-alpha and PTEN, were H3K27me3-positive, and had undetectable levels of p53. Sequencing revealed an activating mutation in PI3-kinase (H1047L) and variants of unknown significance in GRK4, FLG, BAZ2A, and CRTC3. DNA methylation array of the PDX demonstrated 1p loss, which is not typically associated with primary DMG, and broad deletion within 9p including CDKN2A/B, MTAP and multiple interferon genes. The methylation profile did not significantly classify with other tumours in the Molecular Neuropathology database (molecularneuropathology.org/mnp). We describe the first reported PDX model of radiation-associated DMG following medulloblastoma, which recapitulates the patient disease and is molecularly distinct from primary DMG. Interrogation of this model through RNA and whole genome sequencing presents a valuable opportunity to better understand and identify novel therapeutic vulnerabilities against this currently incurable disease.
DIPG-54. A NON-INVASIVE PROGNOSTIC CIRCULATING miRNAs SIGNATURE IN DIFFUSE INTRINSIC PONTINE GLIOMAS
Authors: Iannò Maria Federica , Schiavello Elisabetta , Carenzo Andrea , Anichini Andrea , Biassoni Veronica , Gandola Lorenza , De Cecco Loris , Massimino Maura 
Published: December 2020

Abstract
Diffuse intrinsic pontine gliomas (DIPG) are the most common brainstem tumors of childhood and represent one of the most challenging paediatric tumours to treat. A non-randomized, open label phase II pilot study was conducted at Fondazione IRCCS Istituto Nazionale Tumori (Milan) to assess the efficacy in terms of objective response rate according to the RECIST criteria of combining nimotuzumab and vinorelbine with radiation in newly-diagnosed DIPG. Serum specimens were collected at baseline. microRNA expression profiling was performed using Agilent platform and Human miRNA SureSelect 8x60K containing 2006 miRNAs annotated on miRBase19.0. Primary data analysis yielded a matrix containing 330 detectable miRNA. Association with PFS allowed us to disclose a signature of 10 miRNAs able to stratify high and low risk patients (HR=4.33, 95%CI 1.49–12.54; p=4.27E-05). To test the 10 ct-miRNA model performance, we collected an independent cohort of the same sample size (n=24) and we derived the index values and risk stratification. The distribution of index values covers a range similar to the discovery cohort. Imposing the signature threshold patients were divided in high/low risk and Kaplan-Meier curves confirmed the different PFS time for the two groups with HR=3.5 (95%CI: 1.8–8.01, p-value=0.0002) for the high-risk patients, reaching AUC=0.833. Our signature is a biomarker based on non-invasive procedures for prognosis able to enter into clinical practice. Further validation on multicenter case series is warranted.
DIPG-59. UPREGULATION OF PRENATAL PONTINE ID1 SIGNALING IN DIPG
Authors: Harris Micah K , Yadav Viveka Nand , Stallard Stefanie , Woo Rinette , Siddaway Robert , Qin Tingting , Mullan Brendan , Miklja Zachary , Siada Ruby , Ravindran Ramya , Cao Xuhong , Pasternak Amy , Castro Maria G , Lowenstein Pedro R , Mody Rajen , Chinnaiyan Arul , Hawkins Cynthia , Desprez Pierre , McAllister Sean , Venneti Sriram , Koschmann Carl 
Published: December 2020

Abstract

BACKGROUND
Diffuse intrinsic pontine gliomas (DIPGs) are lethal pediatric brain tumors with no curative therapies. Inhibitor of DNA binding (ID) proteins are key regulators of gene differentiation during embryogenesis. Previous work has shown that H3F3A and ACVR1 mutations increase ID1 expression in cultured astrocytes, but this has not been validated in human DIPG, nor has the regulation and targetability of ID1 been explored in DIPG.

RESULTS
Analysis of post-mortem tissue and multiple human datasets showed ID1 to be elevated in DIPG, and to correlate with reduced survival. In a multi-focal autopsy of a DIPG case, we also found ID1 expression to be heterogeneous and to correlate with tumor invasion. Chromatin immunoprecipitation qPCR (ChIP-qPCR) revealed elevated H3K27ac and low H3K27me3 at ID1 regulatory regions (enhancers/promoters) in DIPG tissue compared to normal brain, regardless of H3 or ACVR1 mutation status. Analysis of publicly-available ISH and ChIP-sequencing data of developing murine brains revealed H3K27ac at ID1 enhancers to be elevated in the prenatal hindbrain compared to prenatal forebrain and midbrain, and all postnatal brain regions. ID1 shRNA-mediated knockdown of primary human H3K27M DIPG cells (DIPG007) significantly reduced invasion and migration. We also treated DIPG007 cells with cannabidiol (CBD) and found reduced viability at clinically relevant dosing (IC50=2.4 uM) with dose-dependent reduction in ID1 protein.

CONCLUSIONS
These findings indicate that a multifactorial (genetic and regionally-based) epigenetic upregulation of ID1 drives DIPG invasiveness and is targetable with CBD. ID1 knockdown and CBD treatment experiments in murine models of DIPG are ongoing.
DIPG-73. SENESCENCE ASSOCIATED SECRETORY PHENOTYPE AS A MECHANISM OF RESISTANCE AND THERAPEUTIC VULNERABILITY IN BMI1 INHIBITOR TREATED DIPG
Authors: Balakrishnan Ilango , Danis Etienne , Pierce Angela , Madhavan Krishna , Wang Dong , Dahl Nathan , Bridget Sanford , Birks Diane K , Davidson Nate , Metselaar Dennis S , Neel Hans , Donson Andrew , Griesinger Andrea , Katagi Hiroaki , Vijmasi Trinka , Sola Ismail , Alimova Irina , Fosmire Susan , Hulleman Esther , Serkova Natalie J , Hashizume Rintaro , Hawkins Cynthia , Carcaboso Angel Montero , Gupta Nalin , Jones Ken , Foreman Nicholas , Green Adam , Vibhakar Rajeev , Venkataraman Sujatha 
Published: December 2020

Abstract

BACKGROUND
Diffuse intrinsic pontine gliomas (DIPGs) driven by mutations in the histone 3 (H3) gene (H3K27M) are aggressive pediatric brain tumors for which there is no curative therapy.

METHODS
To identify novel therapeutic targets we performed a high throughput drug screen combined with an epigenetically targeted RNAi screen using H3K27M and H3.3 WT DIPG cells.

RESULTS
Chemical and genetic depletion of BMI1 in vitro resulted in inhibition of clonogenicity and cell self-renewal consistent with previous studies. We show for the first time that clinically relevant BMI1 inhibitors attenuates growth of orthotopic DIPG xenografts as measured by MRI and prolong survival in vivo. We found that BMI1 inhibition drives phenotypic cellular senescence and that the senescent cells were able reactivate to form new neurospheres in vitro and tumor growth in vivo. RNA-seq, ChIP-Seq and immuno-proteomic analysis revealed that the senescent cells induced the expression of the Senescence Associated Secretory Phenotype (SASP) cytokines by increasing occupancy of activated histone marks at SASP factor promoters. The SASP results in increased expression of anti-apoptotic BH3 proteins including BCLxl, and BCL2. Treatment of the PTC028 treated senescent DIPG cells with BH3 mimetics induces apoptosis and clears the senescent cells. Combining BH3 mimetics with BMI1 inhibition attenuates tumor growth in vivo synergistically and significantly prolongs survival of DIPG bearing mice compared to BMI1 inhibition alone.

CONCLUSION
These data inform the current trial of BMI1 inhibition as a monotherapy and predict the need for adding BH3 mimetics to achieve efficacy.
DIPG-74. RE-IRRADIATION OF DIPG: DATA FROM THE INTERNATIONAL DIPG REGISTRY
Authors: Lafay-Cousin Lucie , Lane Adam , Schafer Austin , Saab Raya , Cheng Sylvia , Bandopadhayay Pratiti , Zaghloul Mohamed , El-Ayadi Motasem , Dorris Kathleen , Packer Roger , Kilburn Lindsey , Minturn Jane , Dodgshun Andrew , Parkin Sara , Lombardi Mercedes Garcia , Cohen Kenneth , Gass David , Goldman Stewart , Sandler Eric , Warren Katherine , Greiner Robert , Gottardo Nicholas , Dholaria Hetal , Hassall Tim , Coven Scott , Hansford Jordan , Samson Yvan , Leary Sarah , Bartels Ute , Bouffet Eric , Ma Jie , Tinkle Christopher , Monje-Deisseroth Michelle , Fisher Paul , Tsui Karen , Ziegler David , Chintagumpala Murali , Gururangan Sridharan , Wagner Lars , Koschmann Carl , DeWire-Schottmiller Mariko , Leach James , Jones Blaise , Fuller Christine , Drissi Rachid , Chaney Brooklyn , Black Katie , Fouladi Maryam , Strother Douglas 
Published: December 2020

Abstract

PURPOSE
To review data from DIPG Registry patients recorded to have received a second course of radiation therapy (rRT).

METHODS
The International DIPG Registry was searched for patients with DIPG who were treated with a known dose of rRT. Doses of rRT, timing from initial diagnosis and primary radiation therapy (pRT), radiographic response to rRT and survival from diagnosis (OS) were evaluated.

RESULTS
Sixty (11.2%) of 535 Registry patients underwent rRT; dose was provided for 44 patients. Median (range) data from those 44 revealed that rRT was given at 12 (2–65) months from initial diagnosis of DIPG and at 9.6 (1–61) months from completion of pRT at a dose of 26.7 (1.8–74) Gy. After completion of rRT, MRI showed response, progression, stable disease or was not available in 19, 8, 3 and 14 patients, respectively. Median PFS and OS were 11 and 18.1 months, respectively. 475 Registry patients did not undergo rRT; their ages, duration of symptoms, and primary treatment with or without chemotherapy were not significantly different from the rRT cohort. Median PFS and OS for the non-rRT patients were 6.9 and 10 months, respectively. rRT patients were more likely to have had radiographic evidence of tumor necrosis at diagnosis than non-rRT patients.

CONCLUSIONS
Administration of rRT to patients with DIPG has been inconsistent with respect to timing and dose. Toxicity, response and quality of life data are incomplete, but survival appears to be lengthened with rRT. Prospective clinical trials will elucidate benefits and risks of rRT.
DIPG-75. PRECISION MEDICINE FOR PAEDIATRIC HIGH-GRADE DIFFUSE MIDLINE GLIOMAS - RESULTS FROM THE ZERO CHILDHOOD CANCER COMPREHENSIVE PRECISION MEDICINE PROGRAM
Authors: Khuong-Quang Dong-Anh , Nagabushan Sumanth , Manoharan Neevika , Arndt Greg , Barahona Paulette , Cowley Mark J , Ekert Paul G , Failes Tim , Bolanos Noemi Fuentes , Gauthier Maely , Gifford Andrew J , Haber Michelle , Kumar Amit , Lock Richard B , Marshall Glenn M , Mayoh Chelsea , Mould Emily , Norris Murray D , Gopalakrishnan Anjana , Omer Natacha , Trebilcock Peter , Trahair Toby N , Tsoli Maria , Tucker Katherine , Wong Marie , Tyrrell Vanessa , Lau Loretta , S, Ziegler David 
Published: December 2020

Abstract
The Australian Zero Childhood Cancer (ZERO) program aims to assess the feasibility of a comprehensive precision medicine approach to improve outcomes for patients with an expected survival &lt;30%. ZERO combines molecular profiling (whole genome sequencing, whole transcriptome sequencing, DNA methylation profiling) with in vitro high-throughput drug screening (HTS) and patient-derived xenograft drug efficacy testing. We report on the cohort of patients with midline high-grade glioma (HGG), including H3-K27M DMG, enrolled on the pilot study (TARGET) and on the ongoing ZERO clinical trial (PRISM). We identified 48 patients with midline HGG. Fresh or cryopreserved samples were submitted in 37 cases and cell culture was attempted in 30/37 cases with 45% success rate. The most commonly mutated genes/pathways identified by molecular profiling include H3-K27M mutations, DNA repair pathway, and PI3K/mTOR pathway. Two targetable fusions (NTRK and FGFR1) were reported. Five patients with germline alterations were identified. Thirty-five (72%) patients received a therapeutic recommendation from the ZERO molecular tumour board and the main recommended therapies were mTOR inhibitors, PARP inhibitors or tyrosine kinase inhibitors. HTS added evidence for the recommended therapy (n=3) or identified novel potential therapy (n=1). Out of the 35 patients, 16 received a recommended drug. Response to treatment was complete response for five months (n=1), partial response for nine months (n=1), stable disease (n=4), and progressive disease (n=10). These results highlight the feasibility of the ZERO platform and the value of fresh biopsy, necessary for pre-clinical drug testing. Targetable alterations were identified leading to clinical benefit in six patients.
DIPG-76. HISTONE H3 PHOSPHORYLATION IN H3K27M MIDLINE GLIOMAS
Authors: Zhang Liang , Day Charles , Hinchcliffe Edward , Daniels David 
Published: December 2020

Abstract
Diffuse midline gliomas (DMG) patients have a dire prognosis despite radiation therapy and there is an urgent need to develop more effective treatments. DMG are characterized by heterozygous mutations in select H3 genes resulting in the replacement of lysine 27 by methionine (K27M) that leads to global epigenetic reprogramming and drives tumorigenesis. We previously reported that pharmacological inhibition of aurora kinase (AKI) may represent a targeted approach for treating tumors with this mutation. Our analysis with both published dataset and patient samples showed that patients with higher aurora kinase A (AKA) expression were associated with worse survival. AKA phosphorylates H3S10 and H3S28 during mitosis. Intriguingly, phosphorylation of the H3S28 (H3S28ph) by AKA blocks PRC2 methyltransferase activity and decreases global H3K27me3 in certain stem cells. We propose that a similar mechanism occurs in H3K27M DMG tumors, where there is a reciprocal relationship between H3S28ph and H3K27me3. We found that AKI significantly decreases H3S28ph while increasing H3K27me3 specifically in H3K27M tumors. To further evaluate the link between the H3K27M mutation and H3 serine phosphorylation, we used CRISPR/Cas9-directed gene editing to silence H3S28ph by replacing serine with alanine (H3S28A) in DIPG cell lines. Ectopic expression of histone H3S28A leads to a prominent epigenetic changes in H3K27M tumors and is similar to AKA inhibition. Overall, this study highlights H3S28ph, one of the targets of AK, is a key driver of epigenetic changes in H3K27M tumors through both direct and indirect changes to H3K27me3 and H3K27ac across the genome.