DIPG-21. INDUCTION OF MITOTIC ABNORMALITIES AND BMI-1 MODULATION TO TREAT DIFFUSE INTRINSIC PONTINE GLIOMA

Abstract Diffuse intrinsic pontine glioma (DIPG) is a poor-prognosis pediatric brain tumor with a median survival of less than one year. No effective therapy is currently available, and no therapeutic advances have been made in several decades. BMI-1 is a member of the multimeric protein complex Polycomb repressor complex 1 (PRC1). It has been implicated in self-renewal of normal and cancer cells, and in DNA damage signaling. We have previously identified BMI-1 as a potential therapeutic target in DIPG and have shown that BMI-1 is highly expressed in DIPG tumors regardless of histone 3 subtype. In the present study, we show that the modulation of BMI-1 leads to DNA damage, M phase cell cycle arrest, chromosome abnormalities and cell death. Furthermore, modulation of BMI-1 sensitizes DIPG patient-derived stem-like cells to ionizing radiation (IR). Treatment of DIPG stem-like cells with PTC596, a BMI-1 modulator, and IR, impairs the kinetics of DNA damage response (DDR). Both DDR foci formation and resolution were delayed, resulting in further reduction in cell viability compared with either treatment alone. In vivo, treatment of mice bearing DIPG xenografts with PTC596 leads to decreased tumor volume and growth kinetics, increased in-tumor apoptosis and sustained animal survival benefit. Gene expression analysis indicates that BMI-1 expression correlates positively with DIPG stemness and BMI-1 signature. Together our findings indicate that BMI-1 modulation is associated with mitotic abnormalities, impaired DDR and cell death, supporting the combination of BMI-1 modulation and radiation as a promising novel therapy to treat children with 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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DDRE-07. TARGETING TUMOR HYPOXIA AND MITOCHONDRIAL METABOLISM WITH ANTI-PARASITIC DRUGS AS AN APPROACH TO IMPROVE THE RADIOSENSITIVITY OF DIFFUSE INTRINSIC PONTINE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noab196.291 ◽

2021 ◽

Vol 23 (Supplement_6) ◽

pp. vi75-vi75

Author(s):

Faiqa Mudassar ◽

Cecilia Chang ◽

Prunella Ing ◽

Kristina Cook ◽

Geraldine O'Neill ◽

...

Keyword(s):

Hypoxia Inducible Factor ◽

Tumor Hypoxia ◽

Pediatric Brain Tumor ◽

Diffuse Intrinsic Pontine Glioma ◽

In Vivo Studies ◽

Pontine Glioma ◽

Antiproliferative Effects ◽

Extracellular Flux

Abstract Diffuse intrinsic pontine glioma (DIPG) is an incurable pediatric brain tumor with a median survival of 12 months. Current management is limited to radiotherapy; however, the tumor recurs secondary to radioresistance. Tumor hypoxia appears to be one of the major contributors to radioresistance of DIPG, as oxygenation is critical to successful radiotherapy treatment. Therefore, strategies to alleviate hypoxia could enhance the effectiveness of radiotherapy and result in improved survival outcomes of patients with DIPG. Recent approaches to target tumor hypoxia are predicated on inhibiting mitochondrial respiration of the tumors to decrease oxygen consumption rate (OCR) and increase oxygenation. Here, we aimed to identify a safe but potent mitochondrial inhibitor that could decrease OCR and hypoxia, and improve the radiosensitivity of DIPG. A subset of anti-parasitic drugs (atovaquone, ivermectin, quinacrine, mefloquine and proguanil) which are known mitochondrial inhibitors were studied against a panel of patient-derived DIPG cell lines. We assessed their antiproliferative effects, OCR inhibition and radiosensitising efficacy using cell proliferation, extracellular flux and colony formation assays. Among the five tested drug candidates, atovaquone was found to be the most potent OCR inhibitor with minimal antiproliferative effects on DIPG cultures. It also decreased hypoxia in 3-dimensional DIPG neurospheres, reduced the expression of hypoxia-inducible factor-1α and improved the radiosensitivity of neurospheres of DIPG. Its anti-mitochondrial role was further confirmed by inhibition of various mitochondrial parameters and increase in reactive oxygen species. Overall, these results provide promising in vitro evidence of atovaquone as a hypoxia modifier and radiosensitiser in DIPG and pave a way for rapid translation to in vivo studies.

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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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DIPG-40. TARGETING MASTER REGULATOR DEPENDENCIES IN DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG)

Neuro-Oncology ◽

10.1093/neuonc/noaa222.087 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii294-iii295

Author(s):

Jovana Pavisic ◽

Chankrit Sethi ◽

Chris Jones ◽

Stergios Zacharoulis ◽

Andrea Califano

Keyword(s):

Gene Expression ◽

Expression Profiles ◽

Treatment Options ◽

Diffuse Intrinsic Pontine Glioma ◽

Low Grade ◽

Precision Oncology ◽

Pontine Glioma ◽

Convection Enhanced Delivery ◽

Master Regulator

Abstract Diffuse intrinsic pontine glioma (DIPG) remains a fatal disease with no effective drugs to date. Mutation-based precision oncology approaches are limited by lack of targetable mutations and genetic heterogeneity. We leveraged systems biology methodologies to discover common targetable disease drivers—master regulator proteins (MRs)—in DIPG to expand treatment options. Using the metaVIPER algorithm, we interrogated an integrated low grade glioma and GBM gene regulatory network with 31 DIPG-gene expression signatures to identify tumor-specific MRs by differential expression of their transcriptional targets. Unsupervised clustering identified MR signatures of upregulated activity in RRM2/TOP2A in 13 patients, CD3D in 5 patients, and MMP7, TACSTD2, RAC2 and SLC15A1/SLC34A2 in individual patients, all of which can be targeted. Notably, intratumoral administration of etoposide by convection enhanced delivery was effective in murine proneural gliomas in which TOP2 was identified as a MR while RRM2—targetable by drugs such as cladribine—has been shown to be a positive regulator of glioma progression whose knock-down inhibits tumor growth. We also prioritized drugs by their ability to reverse MR-activity signatures using a large drug-perturbation database. Patients clustered by predicted drug sensitivities with distinct groups of tumors predicted to respond to proteasome inhibitors, Thiotepa or Volasertib all of which have early evidence in treating gliomas. We will refine this analysis in a multi-institutional study of >100 patient gene expression profiles to define MR signatures driving known biological/molecular disease subtypes, use DIPG cell lines recapitulating common MR architectures to optimize therapy prioritization, and validate our findings in vivo.

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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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N-(3'-acetyl-8-nitro-2,3-dihydro-1H,3'H-spiro[quinoline-4,2'-[1,3,4]thiadiazol]-5'-yl) acetamides Induced Cell death in MCF-7 cells via G2/M Phase Cell Cycle Arrest

New Journal of Chemistry ◽

10.1039/d1nj02550c ◽

2022 ◽

Author(s):

Selvaraj Shyamsivappan ◽

Raju Vivek ◽

Thangaraj Suresh ◽

Palanivel Naveen ◽

Kaviyarasu Adhigaman ◽

...

Keyword(s):

Cell Cycle ◽

Cell Death ◽

Cell Cycle Arrest ◽

Spectroscopic Studies ◽

Phase Cell ◽

X Ray ◽

Cycle Arrest ◽

M Phase ◽

Mcf 7

A progression of new N-(3'-acetyl-8-nitro-2,3-dihydro-1H,3'H-spiro[quinoline-4,2'-[1,3,4]thiadiazol]-5'-yl) acetamide derivatives were synthesized from potent 8-nitro quinoline-thiosemicarbazones. The synthesized compounds were characterized by different spectroscopic studies and single X-ray crystallographic studies. The compounds were...

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EPCT-06. A PHASE I STUDY OF MULTI-TARGETED THERAPY IN NEWLY DIAGNOSED OR PROGRESSIVE DIFFUSE INTRINSIC PONTINE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noaa222.130 ◽

2020 ◽

Vol 22 (Supplement_3) ◽

pp. iii304-iii305

Author(s):

Muhammad Baig ◽

Jason Johnson ◽

Sumit Gupta ◽

Zsila Sadighi ◽

Wafik Zaky ◽

...

Keyword(s):

Targeted Therapy ◽

Maintenance Therapy ◽

Phase I ◽

Phase I Study ◽

Diffusion Tensor ◽

Diffuse Intrinsic Pontine Glioma ◽

Newly Diagnosed ◽

Pontine Glioma ◽

Dose Limiting Toxicity

Abstract BACKGROUND Diffuse intrinsic pontine glioma (DIPG) constitutes 80% of pediatric brain stem tumors with a median survival of 12 months. The PI3K/AKT/mTOR pathway is a key oncogenic driver of this tumor. Targeting the chromatin dysregulation through HDAC inhibition, demonstrated benefit in vivo and vitro studies. We completed the first study as a multi-targeted therapy using SAHA and temsirolimus in pediatric DIPG. METHODS After receiving institutional IRB approval, we enrolled 6 patients on this phase I study using a 3 + 3 statistical design. Patients were divided into stratum 1 and stratum 2, based on newly diagnosed or relapsed DIPG respectively. Stratum I patients received radiation therapy concurrently with vorinostat, followed by maintenance therapy with vorinostat and temsirolimus for 10 cycles (28 day cycle), while in stratum II patients received vorinostat and temsirolimus for 12 cycles. Neuroimaging including diffusion tensor imaging were evaluated where feasible. RESULTS Three patients were enrolled in each of the stratum. One patient in stratum 1 completed therapy, 2 other demonstrated progressive disease (PD) after 4th and 1st cycle of maintenance therapy respectively. In stratum 2 all patients progressed 2 months after the start of therapy. However no dose-limiting toxicity (DLT) was noted. The patient in stratum 1 who completed therapy, remained free of PD 21 months after diagnosis with continued improvements in the volume of enhancing and T2 hyperintense disease. CONCLUSION Although no significant benefit was seen as compared to historical controls during this study, no dose limiting toxicity was noticed with this treatment.

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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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Novel Thiadiazoline Spiro Quinoline Analogues Induced Cell death in MCF-7 cells via G2/M Phase Cell Cycle Arrest

10.21203/rs.3.rs-289802/v1 ◽

2021 ◽

Author(s):

Selvaraj Shyamsivappan ◽

Raju Vivek ◽

Thangaraj Suresh ◽

Adhigaman Kaviyarasu ◽

Sundarasamy Amsaveni ◽

...

Keyword(s):

Cell Cycle ◽

Cell Death ◽

Cell Cycle Arrest ◽

Spectroscopic Studies ◽

Phase Cell ◽

Quinoline Derivatives ◽

Cycle Arrest ◽

M Phase ◽

Mcf 7

Abstract A progression of novel thiadiazoline spiro quinoline derivatives were synthesized from potent thiadiazoline spiro quinoline derivatives . The synthesized compounds portrayed by different spectroscopic studies and single X-ray crystallographic studies. The compounds were assessed for in vitro anticancer properties towards MCF-7 and HeLa cells. The compounds showed superior inhibition action MCF-7 malignant growth cells. Amongst, the compound 4a showed significant inhibition activity, the cell death mechanism was evaluated by fluorescent staining, and flow cytometry, RT-PCR, and western blot analyses. The in vitro anticancer results revealed that the compound 4a induced apoptosis by inhibition of estrogen receptor alpha (ERα) and G2/M phase cell cycle arrest. The binding affinity of the compounds with ERα and pharmacokinetic properties were confirmed by molecular docking studies.

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