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

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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ABC Transporter Inhibition Plus Dexamethasone Enhances the Efficacy of Convection Enhanced Delivery in H3.3K27M Mutant Diffuse Intrinsic Pontine Glioma

Neurosurgery ◽

10.1093/neuros/nyz212 ◽

2019 ◽

Vol 86 (5) ◽

pp. 742-751 ◽

Cited By ~ 3

Author(s):

Vadim Tsvankin ◽

Rintaro Hashizume ◽

Hiroaki Katagi ◽

James E Herndon ◽

Christopher Lascola ◽

...

Keyword(s):

Abc Transporter ◽

Kinase Inhibitor ◽

Mutant Cell ◽

Diffuse Intrinsic Pontine Glioma ◽

Pontine Glioma ◽

Convection Enhanced Delivery ◽

P Glycoprotein ◽

Magnetic Resonance Imaging Mri

Abstract BACKGROUND An impermeable blood–brain barrier and drug efflux via ATP-binding cassette (ABC) transporters such as p-glycoprotein may contribute to underwhelming efficacy of peripherally delivered agents to treat diffuse intrinsic pontine glioma (DIPG). OBJECTIVE To explore the pharmacological augmentation of convection-enhanced delivery (CED) infusate for DIPG. METHODS The efficacy of CED dasatinib, a tyrosine kinase inhibitor, in a transgenic H3.3K27M mutant murine model was assessed. mRNA expression of ABCB1 (p-glycoprotein) was analyzed in 14 tumor types in 274 children. In Vitro viability studies of dasatinib, the p-glycoprotein inhibitor, tariquidar, and dexamethasone were performed in 2 H3.3K27M mutant cell lines. Magnetic resonance imaging (MRI) was used to evaluate CED infusate (gadolinium/dasatinib) distribution in animals pretreated with tariquidar and dexamethasone. Histological assessment of apoptosis was performed. RESULTS Continuous delivery CED dasatinib improved median overall survival (OS) of animals harboring DIPG in comparison to vehicle (39.5 and 28.5 d, respectively; P = .0139). Mean ABCB1 expression was highest in K27M gliomas. In Vitro, the addition of tariquidar and dexamethasone further enhanced the efficacy of dasatinib (P < .001). In Vivo, MRI demonstrated no difference in infusion dispersion between animals pretreated with dexamethasone plus tariquidar prior to CED dasatinib compared to the CED dasatinib. However, tumor apoptosis was the highest in the pretreatment group (P < .001). Correspondingly, median OS was longer in the pretreatment group (49 d) than the dasatinib alone group (39 d) and no treatment controls (31.5 d, P = .0305). CONCLUSION ABC transporter inhibition plus dexamethasone enhances the efficacy of CED dasatinib, resulting in enhanced tumor cellular apoptosis and improved survival in H3.3K27M mutant DIPG.

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PDTM-04. EARLY DETECTION BY MRI OF MOUSE MODELS WITH DIFFUSE INTRINSIC PONTINE GLIOMA

Neuro-Oncology ◽

10.1093/neuonc/noz175.780 ◽

2019 ◽

Vol 21 (Supplement_6) ◽

pp. vi187-vi187

Author(s):

Lincy Thomas ◽

Rheal Towner ◽

Rafal Gulej ◽

Nataliya Smith ◽

Michelle Zalles ◽

...

Keyword(s):

Tumor Growth ◽

Mouse Models ◽

Treatment Options ◽

Diffuse Intrinsic Pontine Glioma ◽

Control Group ◽

Pontine Glioma ◽

Dismal Prognosis ◽

Magnetic Resonance Imaging Mri ◽

Tumor In Childhood

Abstract Diffuse intrinsic pontine glioma (DIPG) is the most common brainstem tumor in childhood with a very devastating prognosis and no curative treatment options as of yet. Approximately 300 children in the U.S. are diagnosed with DIPG each year. Our project hopes to assess the effectiveness of OKlahoma Nitrone-007 (OKN-007) as a therapeutic agent for DIPG. This agent has shown promise in prior studies involving pediatric glioma mouse models by decreasing growth of blood vessels, which is essential for any tumor progression, and by decreasing temozolomide (TMZ) resistance when used as adjunct therapy in adult GBM. We have successfully created an in vivo DIPG model using post-mortem patient-derived neurospheres, harboring the H3 K27M mutation, injected into the pontine region of immunocompromised mouse (SCID) brainstems via a stereotaxic device. After surgical implantation, mice are imaged every week using a 7.0 Tesla 30-cm bore Bruker Biospec Magnetic Resonance Imaging (MRI) system to assess tumor growth and progression of disease. We describe to you the first pre-clinical DIPG mouse model that shows evidence of tumor growth as early as 42 days, as detected on T2-weighted MR images. Another characteristic feature is that the blood-brain barrier (BBB) is intact in this DIPG model, as assessed by contrast-enhanced MRI. Additional MRI methods, including diffusion-weighted imaging (DWI), and perfusion imaging (arterial spin labeling) are also evaluated. Prior pre-clinical DIPG mouse models only had tumor detection by MRI 78 days after implantation. Once the tumors are large enough for treatment (clinically relevant), we separate the mice into a control group (no treatment), OKN-007 treatment alone, as well as combination therapy with OKN-007 and TMZ. With the dismal prognosis and limited effective chemotherapy available for DIPG, there is significant room for continued research studies to help clinicians better understand and treat pediatric DIPG patients.

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Genome-Wide Analyses Identify Recurrent Amplifications of Receptor Tyrosine Kinases and Cell-Cycle Regulatory Genes in Diffuse Intrinsic Pontine Glioma

Journal of Clinical Oncology ◽

10.1200/jco.2011.35.5677 ◽

2011 ◽

Vol 29 (30) ◽

pp. 3999-4006 ◽

Cited By ~ 194

Author(s):

Barbara S. Paugh ◽

Alberto Broniscer ◽

Chunxu Qu ◽

Claudia P. Miller ◽

Junyuan Zhang ◽

...

Keyword(s):

Gene Expression ◽

Cell Cycle ◽

Tyrosine Kinases ◽

Receptor Tyrosine Kinases ◽

Diffuse Intrinsic Pontine Glioma ◽

Regulatory Genes ◽

Low Grade ◽

Pontine Glioma ◽

Gene Expression Signatures ◽

Cell Cycle Regulatory Genes

Purpose Long-term survival for children with diffuse intrinsic pontine glioma (DIPG) is less than 10%, and new therapeutic targets are urgently required. We evaluated a large cohort of DIPGs to identify recurrent genomic abnormalities and gene expression signatures underlying DIPG. Patients and Methods Single-nucleotide polymorphism arrays were used to compare the frequencies of genomic copy number abnormalities in 43 DIPGs and eight low-grade brainstem gliomas with data from adult and pediatric (non-DIPG) glioblastomas, and expression profiles were evaluated using gene expression arrays for 27 DIPGs, six low-grade brainstem gliomas, and 66 nonbrainstem low-grade gliomas. Results Frequencies of specific large-scale and focal imbalances varied significantly between DIPGs and nonbrainstem pediatric glioblastomas. Focal amplifications of genes within the receptor tyrosine kinase–Ras–phosphoinositide 3-kinase signaling pathway were found in 47% of DIPGs, the most common of which involved PDGFRA and MET. Thirty percent of DIPGs contained focal amplifications of cell-cycle regulatory genes controlling retinoblastoma protein (RB) phosphorylation, and 21% had concurrent amplification of genes from both pathways. Some tumors showed heterogeneity in amplification patterns. DIPGs showed distinct gene expression signatures related to developmental processes compared with nonbrainstem pediatric high-grade gliomas, whereas expression signatures of low-grade brainstem and nonbrainstem gliomas were similar. Conclusion DIPGs comprise a molecularly related but distinct subgroup of pediatric gliomas. Genomic studies suggest that targeted inhibition of receptor tyrosine kinases and RB regulatory proteins may be useful therapies for DIPG.

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PDTM-47. REAL TIME IN VIVO MONITORING OF 18F-LABELED PANOBINOSTAT PHARMAKOKINETICS FOR TREATMENT OF DIFFUSE INTRINSIC PONTINE GLIOMA (DIPG) VIA CONVECTION ENHANCED DELIVERY (CED)

Neuro-Oncology ◽

10.1093/neuonc/noy148.886 ◽

2018 ◽

Vol 20 (suppl_6) ◽

pp. vi213-vi214

Author(s):

Umberto Tosi ◽

Harikrishna Kommidi ◽

Uday Bhanu Maachani ◽

Christopher Marnell ◽

Hua Guo ◽

...

Keyword(s):

Real Time ◽

Diffuse Intrinsic Pontine Glioma ◽

Pontine Glioma ◽

Convection Enhanced Delivery ◽

In Vivo Monitoring

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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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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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Transcriptome analysis of gravitational effects on mouse skeletal muscles under microgravity and artificial 1 g onboard environment

Scientific Reports ◽

10.1038/s41598-021-88392-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Risa Okada ◽

Shin-ichiro Fujita ◽

Riku Suzuki ◽

Takuto Hayashi ◽

Hirona Tsubouchi ◽

...

Keyword(s):

Gene Expression ◽

Muscle Mass ◽

Muscle Atrophy ◽

Transcriptome Analysis ◽

Fiber Type ◽

Expression Profiles ◽

Space Station ◽

Gene Expression Profiles

AbstractSpaceflight causes a decrease in skeletal muscle mass and strength. We set two murine experimental groups in orbit for 35 days aboard the International Space Station, under artificial earth-gravity (artificial 1 g; AG) and microgravity (μg; MG), to investigate whether artificial 1 g exposure prevents muscle atrophy at the molecular level. Our main findings indicated that AG onboard environment prevented changes under microgravity in soleus muscle not only in muscle mass and fiber type composition but also in the alteration of gene expression profiles. In particular, transcriptome analysis suggested that AG condition could prevent the alterations of some atrophy-related genes. We further screened novel candidate genes to reveal the muscle atrophy mechanism from these gene expression profiles. We suggest the potential role of Cacng1 in the atrophy of myotubes using in vitro and in vivo gene transductions. This critical project may accelerate the elucidation of muscle atrophy mechanisms.

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Receptor-driven invasion profiles in diffuse intrinsic pontine glioma (DIPG)

Neuro-Oncology Advances ◽

10.1093/noajnl/vdab039 ◽

2021 ◽

Author(s):

Anju Karki ◽

Noah E Berlow ◽

Jin-Ah Kim ◽

Esther Hulleman ◽

Qianqian Liu ◽

...

Keyword(s):

Gene Expression ◽

Growth Factor ◽

Protein Expression ◽

Cell Viability ◽

Rna Sequencing ◽

Cell Invasion ◽

Growth Factor Receptor ◽

Diffuse Intrinsic Pontine Glioma ◽

Sequencing Data ◽

Pontine Glioma

Abstract Background Diffuse intrinsic pontine glioma (DIPG) is a devastating pediatric cancer with unmet clinical need. DIPG is invasive in nature, where tumor cells interweave into the fiber nerve tracts of the pons making the tumor unresectable. Accordingly, novel approaches in combating the disease is of utmost importance and receptor-driven cell invasion in the context of DIPG is under-researched area. Here we investigated the impact on cell invasion mediated by PLEXINB1, PLEXINB2, platelet growth factor receptor (PDGFR)α, PDGFRβ, epithelial growth factor receptor (EGFR), activin receptor 1 (ACVR1), chemokine receptor 4 (CXCR4) and NOTCH1. Methods We used previously published RNA-sequencing data to measure gene expression of selected receptors in DIPG tumor tissue versus matched normal tissue controls (n=18). We assessed protein expression of the corresponding genes using DIPG cell culture models. Then, we performed cell viability and cell invasion assays of DIPG cells stimulated with chemoattractants/ligands. Results RNA-sequencing data showed increased gene expression of receptor genes such as PLEXINB2, PDGFRα, EGFR, ACVR1, CXCR4 and NOTCH1 in DIPG tumors compared to the control tissues. Representative DIPG cell lines demonstrated correspondingly increased protein expression levels of these genes. Cell viability assays showed minimal effects of growth factors/chemokines on tumor cell growth in most instances. Recombinant SEMA4C, SEM4D, PDGF-AA, PDGF-BB, ACVA, CXCL12 and DLL4 ligand stimulation altered invasion in DIPG cells. Conclusions We show that no single growth factor-ligand pair universally induces DIPG cell invasion. However, our results reveal a potential to create a composite of cytokines or anti-cytokines to modulate DIPG cell invasion.

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Comparative gene expression profiling of mouse ovaries upon stimulation with natural equine chorionic gonadotropin (N-eCG) and tethered recombinant-eCG (R-eCG)

10.21203/rs.3.rs-18763/v5 ◽

2020 ◽

Author(s):

Kwan-Sik Min ◽

Jong-Ju Park ◽

So-Yun Lee ◽

Munkhzaya Byambaragchaa ◽

Myung-Hwa Kang

Keyword(s):

Gene Expression ◽

Chorionic Gonadotropin ◽

Expression Profiles ◽

Expression System ◽

Laboratory Animals ◽

Metabolic Clearance ◽

Qrt Pcr ◽

Significant Difference ◽

Equine Chorionic Gonadotropin

Abstract Background: Equine chorionic gonadotropin (eCG) induces super-ovulation in laboratory animals. Notwithstanding its extensive usage, limited information is available regarding the differences between the in vivo effects of natural eCG (N-eCG) and recombinant eCG (R-eCG). This study aimed to investigate the gene expression profiles of mouse ovaries upon stimulation with N-eCG and R-eCG produced from CHO-suspension (CHO-S) cells. R-eCG gene was constructed and transfected into CHO-S cells and quantified. Subsequently, we determined the metabolic clearance rate (MCR) of N-eCG and R-eCG up to 24 h after intravenous administration through the mice tail vein and identified differentially expressed genes in both ovarian tissues, via quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC).Results: R-eCG was markedly expressed initially after transfection and maintained until recovery on day 9. Glycan chains were substantially modified in R-eCG protein produced from CHO-S cells and eliminated through PNGase F treatment. The MCR was higher for R-eCG than for N-eCG, and no significant difference was observed after 60 min. Notwithstanding their low concentrations, R-eCG and N-eCG were detected in the blood at 24h post-injection. Microarray analysis of ovarian tissue revealed that 20 of 12,816 genes assessed therein were significantly up-regulated and 43 genes were down-regulated by >2-fold in the group that received R-eCG (63 [0.49%] differentially regulated genes in total). The microarray results were concurrent with and hence validated by those of RT-PCR, qRT-PCR, and IHC analyses.Conclusions: The present results indicate that R-eCG can be adequately produced through a cell-based expression system through post-translational modification of eCG and can induce ovulation in vivo. These results provide novel insights into the molecular mechanisms underlying the up- or down-regulation of specific ovarian genes and the production of R-eCG with enhanced biological activity in vivo.

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