PDTM-32. THE NOVEL THERAPEUTIC CURCUMIN ENHANCES TARGETED BACTERIOPHAGE MEDIATED IN-VITRO CELL DEATH IN PRIMARY HUMAN DIFFUSE INTRINSIC PONTINE GLIOMA

Abstract Diffuse intrinsic pontine glioma (DIPG) is an aggressive paediatric brainstem tumour, with a median survival of less than 1 year. Polyamines are intracellular polycations that control important aspects of cell growth and are often upregulated in cancer. Difluoromethylornithine (DFMO) is an FDA-approved inhibitor of the enzyme ornithine decarboxylase (ODC1) which is a key driver of polyamine synthesis. We investigated the efficacy of polyamine pathway inhibitors as a therapeutic strategy against DIPG. We found that there were high over-expression levels of polyamine synthetic enzymes from DIPG primary patient samples and neurosphere cultures. Using alamar blue cytotoxicity and soft-agar clonogenic assays, we found that DFMO inhibited the proliferation of DIPG neurospheres. However, DIPG cells compensated for DFMO inhibition by increasing expression of the polyamine transporter SLC3A2 and subsequently uptake of polyamines. Addition of polyamine transporter inhibitor AMXT 1501 to DFMO led to synergistic inhibition of DIPG proliferation in vitro. Consistent with the in vitro results, the combination of DFMO and AMXT 1501 significantly prolonged the survival of mice bearing 3 different DIPG orthografts with at least 2/3 of the animals surviving up to 160 days. Addition of irradiation further improved the survival of mice treated with DFMO and AMXT 1501. Differential expression analysis showed that the polyamine transporter, SLC3A2, was significantly overexpressed in DIPG and other paediatric brain tumours including high grade gliomas compared with normal brain tissue. Our results suggest that DIPG tumours are exquisitely sensitive to polyamine inhibitors, and that dual blockade of polyamine synthesis and transport is a promising novel therapeutic strategy. AMXT 1501 is currently in clinical development, and following completion of an adult Phase 1 trial, a clinical trial of AMXT 1501 + DFMO for DIPG patients is planned through the CONNECT consortium.

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EXTH-46. ARTIFICIAL INTELLIGENCE-BASED IDENTIFICATION OF COMBINED VANDETANIB AND EVEROLIMUS IN THE TREATMENT OF ACVR1-MUTANT DIFFUSE INTRINSIC PONTINE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa215.400 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii97-ii97

Author(s):

Diana Carvalho ◽

Peter Richardson ◽

Nagore Gene Olaciregui ◽

Reda Stankunaite ◽

Cinzia Emilia Lavarino ◽

...

Keyword(s):

Artificial Intelligence ◽

Cell Viability ◽

Xenograft Model ◽

Diffuse Intrinsic Pontine Glioma ◽

Pontine Glioma ◽

Serine Threonine Kinase ◽

Orthotopic Xenografts ◽

Extended Survival

Abstract Somatic mutations in ACVR1, encoding the serine/threonine kinase ALK2 receptor, are found in a quarter of children with the currently incurable brain tumour diffuse intrinsic pontine glioma (DIPG). Treatment of ACVR1-mutant DIPG patient-derived models with multiple inhibitor chemotypes leads to a reduction in cell viability in vitro and extended survival in orthotopic xenografts in vivo, though there are currently no specific ACVR1 inhibitors licensed for DIPG. Using an Artificial Intelligence-based platform to search for approved compounds which could be used to treat ACVR1-mutant DIPG, the combination of vandetanib and everolimus was identified as a possible therapeutic approach. Vandetanib, an approved inhibitor of VEGFR/RET/EGFR, was found to target ACVR1 (Kd=150nM) and reduce DIPG cell viability in vitro, but has been trialed in DIPG patients with limited success, in part due to an inability to cross the blood-brain-barrier. In addition to mTOR, everolimus inhibits both ABCG2 (BCRP) and ABCB1 (P-gp) transporter, and was synergistic in DIPG cells when combined with vandetanib in vitro. This combination is well-tolerated in vivo, and significantly extended survival and reduced tumour burden in an orthotopic ACVR1-mutant patient-derived DIPG xenograft model. Based on these preclinical data, three patients with ACVR1-mutant DIPG were treated with vandetanib and everolimus. These cases may inform on the dosing and the toxicity profile of this combination for future clinical studies. This bench-to-bedside approach represents a rapidly translatable therapeutic strategy in children with ACVR1 mutant DIPG.

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Diffuse intrinsic pontine glioma: current insights and future directions

Chinese Neurosurgical Journal ◽

10.1186/s41016-020-00218-w ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Dilakshan Srikanthan ◽

Michael S. Taccone ◽

Randy Van Ommeren ◽

Joji Ishida ◽

Stacey L. Krumholtz ◽

...

Keyword(s):

Brain Tumor ◽

Gene Mutations ◽

Pediatric Brain Tumor ◽

Diffuse Intrinsic Pontine Glioma ◽

Pontine Glioma ◽

Current Standard ◽

In Vivo Models ◽

Landscape Models

AbstractDiffuse intrinsic pontine glioma (DIPG) is a lethal pediatric brain tumor and the leading cause of brain tumor–related death in children. As several clinical trials over the past few decades have led to no significant improvements in outcome, the current standard of care remains fractionated focal radiation. Due to the recent increase in stereotactic biopsies, tumor tissue availabilities have enabled our advancement of the genomic and molecular characterization of this lethal cancer. Several groups have identified key histone gene mutations, genetic drivers, and methylation changes in DIPG, providing us with new insights into DIPG tumorigenesis. Subsequently, there has been increased development of in vitro and in vivo models of DIPG which have the capacity to unveil novel therapies and strategies for drug delivery. This review outlines the clinical characteristics, genetic landscape, models, and current treatments and hopes to shed light on novel therapeutic avenues and challenges that remain.

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DIPG-03. THERAPEUTIC TARGETING OF TRANSCRIPTIONAL ELONGATION IN DIFFUSE INTRINSIC PONTINE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa222.055 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii287-iii287

Author(s):

Hiroaki Katagi ◽

Nozomu Takata ◽

Yuki Aoi ◽

Yongzhan Zhang ◽

Emily J Rendleman ◽

...

Keyword(s):

Rna Polymerase Ii ◽

Transcription Elongation ◽

Xenograft Model ◽

Diffuse Intrinsic Pontine Glioma ◽

Transcriptional Elongation ◽

Pontine Glioma ◽

Elongation Complex ◽

Pol Ii ◽

Repair Genes ◽

Novel Therapeutic

Abstract Diffuse intrinsic pontine glioma (DIPG) is highly aggressive brain stem tumor and needed to develop novel therapeutic agents for the treatment. The super elongation complex (SEC) is essential for transcription elongation through release of RNA polymerase II (Pol II). We found that AFF4, a scaffold protein of the SEC, is required for the growth of H3K27M-mutant DIPG cells. In addition, the small molecule SEC inhibitor, KL-1, increased promoter-proximal pausing of Pol II, and reduced transcription elongation, resulting in down-regulate cell cycle, transcription and DNA repair genes. KL-1 treatment decreased cell growth and increased apoptosis in H3K27M-mutant DIPG cells, and prolonged animal survival in our human H3K27M-mutant DIPG xenograft model. Our results demonstrate that the SEC disruption by KL-1 is a novel therapeutic strategy for H3K27M-mutant DIPG.

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MODL-12. DEVELOPMENT OF A NOVEL IMMUNOCOMPETENT MOUSE MODEL FOR DIFFUSE INTRINSIC PONTINE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa222.586 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii413-iii413

Author(s):

Maggie Seblani ◽

Markella Zannikou ◽

Katarzyna Pituch ◽

Liliana Ilut ◽

Oren Becher ◽

...

Keyword(s):

Flow Cytometry ◽

Mouse Model ◽

Growth Factor Receptor ◽

Diffuse Intrinsic Pontine Glioma ◽

Pontine Glioma ◽

Time Of Application ◽

Tumor Associated Antigen ◽

Sarcoma Virus

Abstract Diffuse intrinsic pontine glioma (DIPG) is a devastating brain tumor affecting young children. Immunotherapies hold promise however the lack of immunocompetent models recreating a faithful tumor microenvironment (TME) remains a challenge for development of targeted immunotherapeutics. We propose to generate an immunocompetent DIPG mouse model through induced overexpression of interleukin 13 receptor alpha 2 (IL13Rα2), a tumor-associated antigen overexpressed by glioma cells. A model with an intact TME permits comprehensive preclinical assessment of IL13Rα2-targeted immunotherapeutics. Our novel model uses the retroviral avian leucosis and sarcoma virus (RCAS) for in vivo gene delivery leading to IL13Rα2 expression in proliferating progenitor cells. Transfected cells expressing IL13Rα2 and PDGFB, a ligand for platelet derived growth factor receptor, alongside induced p53 loss via the Cre-Lox system are injected in the fourth ventricle in postnatal pups. We validated the expression of PDGFB and IL13Rα2 transgenes in vitro and in vivo and will characterize the TME through evaluation of the peripheral and tumor immunologic compartments using immunohistochemistry and flow cytometry. We confirmed expression of transgenes via flow cytometry and western blotting. Comparison of survival dynamics in mice inoculated with PDGFB alone with PDGFB+IL13Rα2 demonstrated that co-expression of IL13Rα2 did not significantly affect mice survival compared to the PDGFB model. At time of application, we initiated experiments to characterize the TME. Preliminary data demonstrate establishment of tumors within and adjacent to the brainstem and expression of target transgenes. Preclinical findings in a model recapitulating the TME may provide better insight into outcomes upon translation to clinical application.

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TB-4 Antitumor effects of a novel curcumin derivative curcumin monoglucuronide on glioblastoma cells in vitro and in vivo

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab159.022 ◽

2021 ◽

Vol 3 (Supplement_6) ◽

pp. vi6-vi6

Author(s):

Takashi Fujii ◽

Shun Yamamuro ◽

Masamichi Takahashi ◽

Akihide Kondo ◽

Yoshitaka Narita ◽

...

Keyword(s):

Cell Death ◽

Water Soluble ◽

Dependent Manner ◽

Antitumor Effects ◽

Multiple Cell ◽

Human Gbm ◽

Dose Dependent ◽

Novel Therapeutic

Abstract The therapeutic outcome of glioblastomas (GBMs) is still very poor. Therefore, invention of novel therapeutic methods against GBM cases is considered urgent. The antitumor effects of naturally-derived compounds are attracting attention recently, and therapeutic efficacy of curcumin, a plant-derived compound previously used for multiple purpose, has been indicated in many cancer systems; however, clinical application of curcumin is considered difficult because of its poor bioavailability (under 1 %). Curcumin monoglucuronide (CMG), a water-soluble prodrug of curcumin recently developed for overcoming this weakness, has been demonstrated excellent antitumor effects for several malignancies in vitro and in vivo; therefore, we investigated the effects of CMG against GBM cells. CMG induced cell death of human GBM cells lines (T98G, U251MG, and U87MG) by dose dependent manner by triggering multiple forms of cell death such as apoptosis and perthanatos. Immunoblotting of CMG-treated GBM cell lysates demonstrated activation of multiple cell death signaling. Furthermore, immunodeficiency mice harboring intracerebral U87MG cell xenografts systemically treated by CMG showed significantly prolonged survival compared with control mice. These results suggest CMG would be a novel therapeutic agent against GBM cases.

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Preclinical and clinical evaluation of German-sourced ONC201 for the treatment of H3K27M-mutant diffuse intrinsic pontine glioma

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab169 ◽

2021 ◽

Vol 3 (1) ◽

Author(s):

Ryan J Duchatel ◽

Abdul Mannan ◽

Ameha S Woldu ◽

Tom Hawtrey ◽

Phoebe A Hindley ◽

...

Keyword(s):

Biological Activity ◽

High Resolution Mass Spectrometry ◽

The United States ◽

Diffuse Intrinsic Pontine Glioma ◽

Resonance Spectroscopy ◽

Pontine Glioma ◽

Drug Bioavailability ◽

Proliferation And Apoptosis

Abstract Background Diffuse intrinsic pontine glioma (DIPG) is a fatal childhood brainstem tumor for which radiation is the only treatment. Case studies report a clinical response to ONC201 for patients with H3K27M-mutant gliomas. Oncoceutics (ONC201) is only available in the United States and Japan; however, in Germany, DIPG patients can be prescribed and dispensed a locally produced compound—ONC201 German-sourced ONC201 (GsONC201). Pediatric oncologists face the dilemma of supporting the administration of GsONC201 as conjecture surrounds its authenticity. Therefore, we compared GsONC201 to original ONC201 manufactured by Oncoceutics Inc. Methods Authenticity of GsONC201 was determined by high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. Biological activity was shown via assessment of on-target effects, in vitro growth, proliferation, and apoptosis analysis. Patient-derived xenograft mouse models were used to assess plasma and brain tissue pharmacokinetics, pharmacodynamics, and overall survival (OS). The clinical experience of 28 H3K27M+ mutant DIPG patients who received GsONC201 (2017–2020) was analyzed. Results GsONC201 harbored the authentic structure, however, was formulated as a free base rather than the dihydrochloride salt used in clinical trials. GsONC201 in vitro and in vivo efficacy and drug bioavailability studies showed no difference compared to Oncoceutics ONC201. Patients treated with GsONC201 (n = 28) showed a median OS of 18 months (P = .0007). GsONC201 patients who underwent reirradiation showed a median OS of 22 months compared to 12 months for GsONC201 patients who did not (P = .012). Conclusions This study confirms the biological activity of GsONC201 and documents the OS of patients who received the drug; however, GsONC201 was never used as a monotherapy.

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A High-Throughput In Vitro Drug Screen in a Genetically Engineered Mouse Model of Diffuse Intrinsic Pontine Glioma Identifies BMS-754807 as a Promising Therapeutic Agent

PLoS ONE ◽

10.1371/journal.pone.0118926 ◽

2015 ◽

Vol 10 (3) ◽

pp. e0118926 ◽

Cited By ~ 32

Author(s):

Kyle G. Halvorson ◽

Kelly L. Barton ◽

Kristin Schroeder ◽

Katherine L. Misuraca ◽

Christine Hoeman ◽

...

Keyword(s):

Mouse Model ◽

High Throughput ◽

Therapeutic Agent ◽

Diffuse Intrinsic Pontine Glioma ◽

Genetically Engineered ◽

Drug Screen ◽

Pontine Glioma ◽

Genetically Engineered Mouse Model ◽

Promising Therapeutic Agent

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Characterization of the Blood–Brain Barrier Integrity and the Brain Transport of SN-38 in an Orthotopic Xenograft Rat Model of Diffuse Intrinsic Pontine Glioma

Pharmaceutics ◽

10.3390/pharmaceutics12050399 ◽

2020 ◽

Vol 12 (5) ◽

pp. 399 ◽

Cited By ~ 2

Author(s):

Catarina Chaves ◽

Xavier Declèves ◽

Meryam Taghi ◽

Marie-Claude Menet ◽

Joelle Lacombe ◽

...

Keyword(s):

Blood Brain Barrier ◽

Diffuse Intrinsic Pontine Glioma ◽

Brain Barrier ◽

Brain Delivery ◽

Pontine Glioma ◽

Anticancer Drug Delivery ◽

Blood Brain ◽

The Brain

The blood–brain barrier (BBB) hinders the brain delivery of many anticancer drugs. In pediatric patients, diffuse intrinsic pontine glioma (DIPG) represents the main cause of brain cancer mortality lacking effective drug therapy. Using sham and DIPG-bearing rats, we analyzed (1) the brain distribution of 3-kDa-Texas red-dextran (TRD) or [14C]-sucrose as measures of BBB integrity, and (2) the role of major ATP-binding cassette (ABC) transporters at the BBB on the efflux of the irinotecan metabolite [3H]-SN-38. The unaffected [14C]-sucrose or TRD distribution in the cerebrum, cerebellum, and brainstem regions in DIPG-bearing animals suggests an intact BBB. Targeted proteomics retrieved no change in P-glycoprotein (P-gp), BCRP, MRP1, and MRP4 levels in the analyzed regions of DIPG rats. In vitro, DIPG cells express BCRP but not P-gp, MRP1, or MRP4. Dual inhibition of P-gp/Bcrp, or Mrp showed a significant increase on SN-38 BBB transport: Cerebrum (8.3-fold and 3-fold, respectively), cerebellum (4.2-fold and 2.8-fold), and brainstem (2.6-fold and 2.2-fold). Elacridar increased [3H]-SN-38 brain delivery beyond a P-gp/Bcrp inhibitor effect alone, emphasizing the role of another unidentified transporter in BBB efflux of SN-38. These results confirm a well-preserved BBB in DIPG-bearing rats, along with functional ABC-transporter expression. The development of chemotherapeutic strategies to circumvent ABC-mediated BBB efflux are needed to improve anticancer drug delivery against DIPG.

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