Diffuse Glioma Research Articles

Abstract 525: A comprehensive approach: Copper chelation therapy modulates epigenetic, kinase signaling and metabolic pathways in diffuse midline gliomas (DMG)

Abstract Diffuse Midline Gliomas (DMG) are incurable pediatric brain tumors driven by histone mutation H3K27M, globally reducing H3K27 trimethylation altering the epigenome and deregulating gene expression. These mutations often partner with and are strongly integrated into kinase signaling and metabolic alterations, driving aggressive tumor growth with many mechanisms which can compensate for one another and therefore evade traditional single agent therapies. Copper over-accumulation has been linked to epigenetic, kinase and metabolic dysregulation in various cancers and neurological disorders. Copper chelators are clinically approved for use in pediatric Wilson’s Disease patients, improve neurological symptoms and are under clinical investigation for several cancers. We propose copper chelators may simultaneously target these mechanisms in DMG. We performed transcriptomic interrogation of patient datasets, in vitro investigations in a panel of DMG cell lines and an in vivo investigation using an orthotopic xenograft model of DIPG (SU-DIPGVI-Luc). Copper chelator tetraethylenepentamine-pentachloride (TEPA) was used to treat DMG cells. Transcriptomic (RNA-Seq), proteomic, phospho-proteomic and metabolomic (Mass Spectrometry) investigations, western blots and immunofluorescent microscopy determined efficacy and mechanism. In vivo investigation consisted of survival study with concurrent luminescence imaging, histology, and copper assay. We demonstrate copper chaperone transcript expression is increased in DMG patient samples compared to non-DMG samples. In vitro, apoptosis and growth assays demonstrated H3K27M DMG were more sensitive to TEPA than H3-WT DMG. In H3K27M DMG, TEPA downregulated ATP, GTP and SAM metabolism which corresponded with downregulated kinase signaling and altered H3K27 trimethylation and DNA methylation patterns around cell cycle genes. Affected genes included those regulating centrosome segregation and ATP synthesis. Further transcriptomic and proteomic investigations highlighted TEPA downregulated G2-M phase kinase pathways, with immunofluorescence demonstrating TEPA reduced expression of mitotic marker p-H3S10 and epigenetic methylators EZH2 and DNMT1. In vivo, TEPA reduced brain copper accumulation, eliminated tumors and increased survival in an orthotopic patient-derived xenograft DMG model. Collectively, our data indicates TEPA induced multi-modal targeting of M-phase cell cycle progression through epigenetic, kinase signaling and metabolic mechanisms. Efficacy was observed both in vitro and in vivo, providing a promising basis for future investigation of copper chelators in DMG. We propose copper-chelation is a viable therapeutic strategy for DMG patients warranting clinical investigation. Citation Format: Filip Michniewicz, Riccardo Cazzoli, Jessica Bell, Federica Saletta, Ensieh Poursani, Jourdin R. Rouaen, Tyler Shai-Hee, Vu Pham, Toni Rose Jue, Matthew Biery, Liesl Bramberger, Terry Lim, Aaminah Khan, Federico M. Giorgi, Daniele Mercatelli, Chelsea Mayoh, Giuseppe Cirillo, Alexander Macmillan, Renee Whan, Christopher T. Barlow, Maria Tsoli, Nicholas Vitanza, Scott Berry, Pouya Faridi, David Ziegler, Orazio Vittorio. A comprehensive approach: Copper chelation therapy modulates epigenetic, kinase signaling and metabolic pathways in diffuse midline gliomas (DMG) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 525.

Abstract 1437: Generating primary mouse models of diffuse midline glioma through a combination of the RCAS/tv-a retrovirus system and CRISPR/Cas9 gene editing

Abstract Diffuse midline gliomas (DMGs) are deadly brain tumors that arise in the brainstem of children and young adults, resulting in a median survival of less than two years. Genetically engineered mouse models (GEMMs) are critical to studying tumorigenesis and tumor-immune interactions in DMG, which may inform the design of new urgently-needed treatment approaches. One approach to generate DMG GEMMs uses RCAS/tv-a, an avian retrovirus gene delivery system to express transgenes in specific brain cell lineages in the mouse brain. However, this approach often requires resource-intensive breeding to generate mice with the desired genetic alterations in their germline. As a result, we aimed to establish a new approach that combines this system with CRISPR/Cas9 gene editing technology. This methodology has been described for model adult supratentorial gliomas in mice but has not been described for pediatric or brainstem gliomas. To express Cas9 and the avian retrovirus receptor TVA in mouse neural stem cells, we bred mice of genotype Nestin-TVA; Nestin-Cre; LoxP-STOP-LoxP-Cas9-EGFP. RCAS retrovirus plasmids were generated containing various guide RNAs (gRNAs) targeting DMG-relevant genes for disruption by Cas9, including Trp53, Cdkn2a, Atm, Ppm1d, Pten, and a non-targeting control (Cntl). For each gRNA, two plasmids were generated, one with a platelet-derived growth factor beta ligand (PDGFB) oncogene driver and one with a blue fluorescent protein (BFP) marker. In a pilot experiment, avian fibroblast cells transduced with RCAS-Trp53_gRNA_BFP and RCAS-Cntl_gRNA-PDGFB were injected into postnatal day 4 mouse brainstems of the aforementioned genotype and observed for tumor formation. High grade tumor formation was observed. We also observed high grade tumors in mice of genotype Nestin-TVA; LoxP-STOP-LoxP-Cas9-EGFP when injected with an additional RCAS-Cre construct, indicating that Cre can be expressed from the mouse germline or delivered via a retrovirus payload to drive tumorigenesis. Immunohistochemistry confirmed tumor features that model human DMG, expression of Cas9 and PDGFB, and loss of p53. Thus, RCAS/tv-a and CRISPR/Cas9 can be combined to model pediatric glioma tumorigenesis in the mouse brainstem. This approach to mouse modeling will streamline future GEMM DMG research by allowing new genes of interest to be rapidly perturbed by simply generating RCAS retrovirus constructs. The workflow may also enable sophisticated experiments such as pooled in vivo genetic experiments that screen gRNAs targeting various tumor suppressor genes or therapeutic targets. Citation Format: Sophie R. Wu, Harrison Q. Liu, Joshua Tolliver, Spencer M. Maingi, Vennesa Valentine, Nerissa T. Williams, Zachary J. Reitman. Generating primary mouse models of diffuse midline glioma through a combination of the RCAS/tv-a retrovirus system and CRISPR/Cas9 gene editing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1437.

Abstract 7564: DNA methylation profiling identifies two distinct groups of oligosarcoma, IDH-mutant with distinct genetic alterations and clinical outcomes

Abstract DNA methylation has been extensively adopted for the classification of brain tumors and is endorsed by current neuropathology guidelines. Recently, oligosarcoma, IDH-mutant has been characterized as a distinct group of IDH mutant gliomas by DNA methylation classification. However, emerging studies revealed the variety in this group. Here, we employed DNA methylation-based t-SNE analysis to characterize oligosarcomas identified by the dkfz brain tumor classifier (v12.5). Thereby, we uncovered that oligosarcomas were segregated into two distinct groups, namely, subgroup A and subgroup B, which were further validated by genetic alterations and clinical outcomes. Next-generation Sequencing revealed subtype A tumors enriched with chr 1p/19q co-deletion, chr 6q loss, CDKN2A/B homogeneous deletion, TERT promoter mutation, and NF1 mutation, while subtype B tumors showed chr7 gaining and TP53 mutation. RNA sequencing and gene set enrichment analysis (GSEA) revealed that neuronal-tumor interaction and muscular progression pathways were more enriched in subtype A tumors. In contrast, subtype B tumors showed enrichment for angiogenesis and mTOR pathways. Additionally, inter-chromosomal fusion genes were more frequently found in subtype A tumors. Clinically, patients with subgroup A oligosarcomas manifested poorer survival and distinct imaging features in magnetic resonance imaging (MRI) compared to those with subgroup B. Collectively, we provided more cases of oligosarcoma, IDH-mutant, confirming the existence of this newly identified group, and revealed the subgroups harboring different genetic alterations and suffering different prognoses, providing new evidence for the molecular pathology in diffuse glioma. Citation Format: Kenan Zhang, Lingyu Liu, Xing Liu, Tao Jiang. DNA methylation profiling identifies two distinct groups of oligosarcoma, IDH-mutant with distinct genetic alterations and clinical outcomes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7564.

Abstract 154: Diffuse midline glioma invasion and metastasis rely on cell-autonomous signaling through a phenotypic switch controlled by BMP7

Abstract Diffuse midline gliomas (DMG) are pediatric tumors with negligible two-year survival after diagnosis characterized by their ability to infiltrate the central nervous system. In the hope of controlling the local growth and slowing the disease all patients receive radiotherapy. However, distant progression occurs frequently in DMG patients. Current clues as to what causes tumor infiltration circle mainly around the tumor microenvironment, but there are currently no known determinants to predict the degree of invasiveness. We use patient-derived glioma stem cells (GSCs) to create patient-specific 3D avatars to model interindividual invasion and elucidate the cellular supporting mechanisms. We show that 3D models mirror the invasive behavior of the parental tumors, thus proving the ability of DMG to infiltrate as an autonomous characteristic of tumor cells. Furthermore, we distinguished two modes of migration, mesenchymal and amoeboid-like, and associated the amoeboid-like modality with GSCs derived from the most invasive tumors. Using transcriptomics of both organoids and primary tumors, we further characterized the invasive amoeboid-like tumors as oligodendrocyte progenitor-like, with highly contractile cytoskeleton and reduced adhesion ability. Moreover, we identified the cell-autonomous BMP7-related signaling as a major regulator of DMG motility and invasion, controlling a switch between two migration modalities. Finally, we deciphered MEK, ERK and Rho/ROCK kinases activated downstream of the BMP7 stimulation as actionable targets controlling tumor cell motility. Our findings identify two new therapeutic avenues. First, patient-derived GSCs represent a predictive tool for stratification of patient with increased risk of metastatic progression in order to adapt their irradiation strategies within weeks after diagnosis. Second, autocrine and short-range BMP7-related signaling becomes a druggable target to prevent DMG spread and metastasis. Citation Format: Marco Bruschi, Lilia Midjek, Yassine Ajlil, Stephanie Vairy, Manon Lancien, Samia Ghermaoui, Thomas Kergrohen, Maite Verreault, Ahmed Idbaih, Carlos Alberto Oliveira de Biagi, Ilon Liu, Mariella G. Filbin, Kevin Beccaria, Thomas Blauwblomme, Stephanie Puget, Arnault Tauziede-Espariat, Pascale Varlet, Volodia Dangouloff-Ros, Nathalie Boddaert, Gwenael Le Teuff, Jacques Grill, Guillaume Montagnac, Nadia Elkathib, Marie-Anne Debily, David Castel. Diffuse midline glioma invasion and metastasis rely on cell-autonomous signaling through a phenotypic switch controlled by BMP7 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 154.

Abstract 7555: Selective inhibition of the CoREST complex as a novel therapeutic target of atypical teratoid rhabdoid tumors

Abstract Atypical teratoid/rhabdoid tumors (AT/RT) are deadly infantile brain tumors, primarily arising from a single recurring biallelic loss-of-function mutation in SMARCB1 which is a member of the SWI-SNF chromatin remodeling complex. The partially functional SWI-SNF complex (without SMARCB1) is able to inhibit EZH2 at most locations of the genome except at gene promoter regions where EZH2 co-localizes with the REST complex. This results in hypermethylation and subsequent repression of genes coding for neuronal differentiation and tumor suppressors. CoREST is an important transcriptional repressor and consists of LSD1 and HDAC1/2 bound together by the scaffolding protein RCOR. Increased activity of EZH2 and the CoREST complex may help AT/RT cells maintain a stem cell-like state, driving its aggressive growth and therapy resistance. We hypothesize that functional inhibition of the CoREST complex by targeting LSD1 and HDAC1/2 might help restore the epigenetic balance lost in AT/RT cells.We selectively inhibited the CoREST complex in AT/RT cells (BT37, CHLA05 and CHLA06) by using a bi-functional LSD1 and HDAC1/2 inhibitor, Corin, which has previously been shown to be effective against melanoma and diffuse midline glioma. Administration of corin to AT/RT cells significantly increased H3K4me1, H3K9Ac and H3K27Ac histone marks (p < 0.001, Western blotting). Corin inhibited AT/RT cell growth and proliferation (MUSE Viacount p<0.05, BrdU immunofluorescence compared to control), and increased apoptosis (cPARP Western blotting, CC3 immunofluorescence, MUSE Annexin V assay, p<0.05 compared to control). Corin appears to be specific in targeting AT/RT as it did not affect brain organoids derived from iPSCs (cPARP Western blotting). Corin induced neuronal differentiation in AT/RT as seen by the increased expression of Beta-3-tubulin, MAP2 and Synaptophysin (Immunofluorescence). Enrichment analysis of differentially expressed genes after whole mRNA sequencing of AT/RT cells treated with corin for 24 h revealed upregulation of pathways related to neuronal differentiation and axonal development and downregulation of pathways related to proliferation and cell cycle (pFDR < 0.05, FC>2). In mice bearing orthotopic CHLA06 tumors, intratumoral delivery of a single dose of corin for 24 h increased H3K27me3 and H3K27ac, demonstrating that corin engaged its target in vivo, reduced growth and induced apoptosis (Ki67, cPARP). Survival studies show a trend toward single agent activity against the very aggressive CHLA06 orthotopic xenograft (increased in median survival from 14 to 35 days compared to control). These studies demonstrate that targeting the CoREST complex disrupts AT/RT epigenetic abnormalities, reversing their stem cell-like state, slowing tumor cell growth, and inducing apoptosis, that may translate into the clinical setting to help improve AT/RT’s dismal survival. Citation Format: Anupa Geethadevi, Marianne Collard, Tyler Findlay, Yiming Deng, Robert Fisher, Nikhil Vaidya, Charles Eberhart, Philip A. Cole, Rhoda Alani, Jeffrey Rubens, Eric Raabe. Selective inhibition of the CoREST complex as a novel therapeutic target of atypical teratoid rhabdoid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7555.

Abstract 2858: Phenotypic screens identify genetic regulators of nanoparticle delivery to pediatric brain tumors

Abstract Pediatric central nervous system tumors are the leading cause of cancer death in children. Diffuse midline glioma (DMG) is a universally fatal pediatric brain tumor and despite many clinical trials over the past decades, less than 10% of patients are long-term survivors. The clinical standard of care is radiotherapy, however it only provides limited symptom relief. There is a clear need to develop creative treatment strategies for patients with DMG. Nanomedicine has the potential to address this challenge, allowing the encapsulation of difficult to deliver therapeutic cargoes, and selectively targeting them to tumors while crossing innate biological barriers. However, a deep understanding of disease-specific nano-bio interactions is crucial to leverage the full potential of these therapies. To functionally validate the role of candidate biomarkers in nanoparticle delivery to DMGs, we performed pooled genetic perturbation screens using a flow based phenotypic output. We developed 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 nanoparticles to DMG. Layer-by-layer electrostatic assembly was used to generate liposomal nanoparticles with a polymer surface coating of hyaluronic acid. Two patient-derived neurosphere models of DMG were transduced with the pooled all-in-one CRISPR/Cas9 library. Following antibiotic selection, cells were incubated with hyaluronic acid or polymeric nanoparticles for 4 or 24 hours and sorted into populations based on nanoparticle affinity. A dynamic cell-sorting strategy was optimized to separate cells infected with inert DNA barcodes based on their degree of nanoparticle-association. DNA was isolated from sorted cells and subjected to next generation sequencing. The enrichment of each single guide was determined relative to matched controls. We found strong agreement between biologic replicates, and determined which genes, when knocked down, shifted nanoparticle uptake into DMG cells. Our pooled phenotypic screen revealed strong biologic regulators of nanoparticle uptake. These can be categorized as formulation dependent and independent, as well as time-dependent. We identified several negative regulators of nanoparticle uptake including members of the mitogen-activated protein kinase (MAPK) and mammalian target of rapamycin (mTOR) pathways. The top target genes are currently being validated in DMG and human neural stem cell models. 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 (intravenous, intraventricular, or intratumoral) to enhance the use of nanomedicine for DMG and other pediatric brain tumors. Citation Format: Marissa Coppola, Julianna Kenny-Serrano, John G. Doench, Paula Hammond, Pratiti Bandopadhayay, Jessica W. Tsai, Joelle Straehla. Phenotypic screens identify genetic regulators of nanoparticle delivery to pediatric brain tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2858.

Abstract 3331: Preclinical combination of ONC206 with radiotherapy and temozolomide in a GBM mouse orthotopic model

Abstract Glioblastoma multiforme (GBM) is the most common form of primary malignant brain tumor in adults. It is also the most aggressive and lethal. Standard of care therapy comprises maximal safe surgical resection followed by adjuvant alkylating agent temozolomide (TMZ) and radiotherapy (RT). There have only been five drugs and one device ever approved by the FDA for the treatment of GBM. The five-year survival rate for GBM patients has shown no notable improvement in the last three decades. We previously reported that the first-in-class imipridone small-molecule Dordaviprone (ONC201) decreases protein chaperone ClpX to unleash mitochondrial protease ClpP activity, integrated stress response and cell death. Preclinical combination of ONC201 (100 mg/kg weekly) with radiotherapy and Temozolomide in a GBM mouse orthotopic model results in reduced tumor burden and prolonged survival. The second generation imipridone ONC206 also activates integrated stress response and decreases ClpX in GBM cells but ONC206 is approximately 20 times more potent than its parent imipridone ONC201. ONC206 0.08 uM in combination with 12.5 uM TMZ and 2 Gy RT reduced the cell viability of GBM cells significantly compared to all single treatments and double treatments. During a short-term treatment of a GBM mouse orthotopic model, ONC206 (50 mg/kg weekly, half of ONC201 doses) synergizes with TMZ and RT to induce more tumor cell apoptosis and inhibits more tumor cell proliferation compared to other groups with single or double treatments. There are two ongoing clinical trials with ONC206: single weekly or multiple-day weekly dose regimens of single-agent, oral ONC206 in patients with recurrent, primary central nervous system (CNS) neoplasms (NCT04541082) and ONC206 alone or in combination with radiation therapy in treating patients with diffuse midline gliomas that is newly diagnosed or has come back (recurrent) or other recurrent primary malignant CNS tumors (NCT04732065). Future studies evaluating the role of immune function, mitochondrial metabolism, dopamine receptors, the ISR and TRAIL pathway in the synergistic effect would support further development of the triple combination regimen of ONC206, TMZ and radiation therapy for GBM clinical trial. Citation Format: Lanlan Zhou, Leiqing Zhang, Jun Zhang, Shengliang Zhang, Wafik S. El-Deiry. Preclinical combination of ONC206 with radiotherapy and temozolomide in a GBM mouse orthotopic model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3331.

Abstract 5470: ONC206 inhibits tumour growth and is a potential novel therapeutic strategy for refractory medulloblastoma

Abstract Medulloblastoma is the most common malignant pediatric brain tumor with a for certain molecular subgroups very low overall survival and therefore an urgent need for novel treatment approaches. Dordaviprone (ONC201) and its chemical derivative with nanomolar potency ONC206 are inhibitors of the dopamine receptor 2 (DRD2) and more importantly induce apoptosis of cancer cells by activation of the mitochondrial caseinolytic protease P (ClpP). ONC201 has shown objective responses in patients with diffuse midline gliomas and is currently being evaluated in the Phase 3 ACTION study. ONC206 is currently in Phase I clinical trials for pediatric and adult patients with primary brain tumors. In this study, we evaluated the preclinical therapeutic effects of ONC206 in medulloblastoma in vitro and in vivo and investigated the molecular mode of action for this imipridone. We found evidence for high expression of ClpP at both the RNA and protein level in medulloblastoma tumours, compared to very low expression in normal brain and normal cerebellum. In addition, we saw a pronounced reduction in cell viability of human Group 3 and Group 4 and murine medulloblastoma cells treated with ONC206 with extremely low IC-50s (range: 14nM - 2μM).After treatment with ONC206, we observed a significant downregulation of mitochondrial electron transport chain complexes I and III and mitochondrial hyperpolarization, as well as an induction of the ATF4 pathway, thereby implying that ONC206 induces an integrated stress response and mitochondrial damage. In order to test the efficacy of ONC206 in vivo, we used murine models of SHH-driven and Group 3 medulloblastoma as well as Group 3 patient-derived xenografts (PDXs). ONC206 led to a significant prolongation of survival in both murine models, with the SHH mice demonstrating a remarkable survival benefit. Mice from both Group 3 PDXs also responded to ONC206, with 25% of ONC206 treated animals exhibiting long-term tumor-free survival. Our results highlight ONC206 as a novel attractive therapeutic option for patients with relapsed medulloblastoma and importantly pave the way for a clinical trial testing the efficacy of ONC206 in the treatment of these patients. Citation Format: Theophilos Tzaridis, Jingbo Liu, Varun Prabhu, Robert Wechsler-Reya, Tobey MacDonald. ONC206 inhibits tumour growth and is a potential novel therapeutic strategy for refractory medulloblastoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5470.

Abstract 5108: Immunomodulatory and anti-tumor effect of radiation and induced telomere damage to treat pediatric high-grade gliomas

Abstract Pediatric high-grade gliomas (pHGGs), including diffuse intrinsic pontine glioma (DIPG) are among the most treatment refractory cancers in children. Despite multimodal therapy, prognosis is dismal with survival of <1 year for DIPG and a 5-year overall survival <10% for other pHGGs. Radiotherapy remains the only standard of care for DIPG that extends the survival by few months. In recent years, immunotherapy is emerging as a potential alternative treatment option. However, several factors have hindered the use of immunotherapy for pHGGs including “cold” immune environment with lack of immune cells infiltration, low tumor mutational burden, and lack of neo-antigen expression that prevents tumor recognition by the immune system. Therefore, novel therapies that activate the immune system while evading the tumor immunosuppression are highly needed. Here, we aim to demonstrate the immunomodulatory anti-tumor effects of THIO (6-thio-2’deoxyguanosine), a nucleoside analog and a telomerase-dependent telomere targeting agent, in DIPG mouse models. Our preclinical in vitro and in vivo data have demonstrated the efficacy of THIO in inducing telomeric damage, G2/M cell cycle arrest, and apoptosis in high-risk medulloblastoma and DIPG. Importantly, we have demonstrated that THIO crosses the blood-brain barrier and specifically targets tumor cells in an orthotopic mouse model of DIPG. THIO was shown to induce anti-tumor immunity through micronuclei formation leading to cGAS-STING pathway mediated activation of the innate and adaptive immune response in colon, lung, and hepatocellular carcinoma tumor models. Our preliminary data demonstrate the THIO-dependent induction of micronuclei formation co-localizing with cGAS and leading to STAT1 activation in DIPG cell lines. We have also shown that THIO synergistically sensitizes DIPG cells to ionizing radiation (IR), significantly decreasing cell proliferation. We are currently testing the combination of THIO+IR in an orthotopic mouse model for DIPG. We will present results on the potential of THIO and IR treatments to stimulate anti-tumor immunity through the activation of STING pathway in a syngeneic mouse model of DIPG. These preclinical studies will support the potential use of THIO and IR to treat children with high-risk pediatric brain tumors. Citation Format: Umaru Banlanjo, Shiva Senthil Kumar, Sergei Gryaznov, Rachid Drissi. Immunomodulatory and anti-tumor effect of radiation and induced telomere damage to treat pediatric high-grade gliomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5108.

Abstract 4731: Targeting Lon protease as novel strategy to treat aggressive IDH mutant diffuse malignant astrocytoma

Abstract While isocitrate dehydrogenase (IDH) wild-type and mutant malignant astrocytoma (IDHwt, IDHmt) are diffuse CNS tumors that have a high degree of parallelism with one another, including microvascular proliferation and necrosis, the IDHwt tumors clinically presents with a higher tumor grade and thus poorer prognosis and survival rate. Isocitrate dehydrogenase mutation (IDH) hinders the hypoxia response in gliomas and promotes an advantageous reduction in both tumor growth and treatment resistance. Since recurrence is high, adequate characterization and identification of potential novel molecular targets in IDHmt mutant diffuse glioma is integral for developing new therapeutic strategies for better control of tumor burden and, thus, improved outcomes. Our previous published work has shown that the hypoxia responsive LONP1 mitochondrial protease is involved in glioma growth and treatment resistance and that LONP1 inhibitors can augment the effect of chemotherapy in IDHwt models. Here, we highlight the downstream activity of LONP1 via the NRF2 pathway and how synergistically, along with the IDH mutation, LONP1 overexpression can promote the subsequent proneural to mesenchymal transition (PMT) induced by stress and other tumor microenvironment signals. By characterizing the interplay between LONP1 and IDH mutation in in-vitro models, we demonstrate that oxidative stress modulates both PMT and TMZ drug resistance. When translated to an in-vivo patient-derived, intracranial orthotopic xenograft model, LONP1 overexpression is associated with decreased survival.Based on our findings, future clinical translation includes the possibility of using LONP1 as a novel target to optimize the standard of care treatment in IDH mutant diffuse astrocytoma. Citation Format: Christopher Douglas, Shashi Jain, Naomi Lomeli, Thao Vu, James Pham, Daniela A. Bota. Targeting Lon protease as novel strategy to treat aggressive IDH mutant diffuse malignant astrocytoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4731.

Discovery of Conformationally Constrained ALK2 Inhibitors.

Despite decades of research on new diffuse intrinsic pontine glioma (DIPG) treatments, little or no progress has been made on improving patient outcomes. In this work, we explored novel scaffold modifications of M4K2009, a 3,5-diphenylpyridine ALK2 inhibitor previously reported by our group. Here we disclose the design, synthesis, and evaluation of a first-in-class set of 5- to 7-membered ether-linked and 7-membered amine-linked constrained inhibitors of ALK2. This rigidification strategy led us to the discovery of the ether-linked inhibitors M4K2308 and M4K2281 and the amine-linked inhibitors M4K2304 and M4K2306, each with superior potency against ALK2. Notably, M4K2304 and M4K2306 exhibit exceptional selectivity for ALK2 over ALK5, surpassing the reference compound. Preliminary studies on their in vivo pharmacokinetics, including blood-brain barrier penetration, revealed that these constrained scaffolds have favorable exposure and do open a novel chemical space for further optimization and future evaluation in orthotopic models of DIPG.

Awake Craniotomy for Gliomas in the Non-Dominant Right Hemisphere: A Comprehensive Review.

Awake surgery has become a standard practice for managing diffuse low-grade gliomas (LGGs), particularly in eloquent brain areas, and is established as a gold standard technique for left-dominant-hemisphere tumors. However, the intraoperative monitoring of functions in the right non-dominant hemisphere (RndH) is often neglected, highlighting the need for a better understanding of neurocognitive testing for complex functions in the right hemisphere. This article aims to comprehensively review the current literature on the benefits of awake craniotomy in gliomas of the non-dominant right hemisphere. A systematic review was conducted using the PubMed and ScienceDirect databases with keywords such as "right hemisphere", "awake surgery", "direct electrical brain stimulation and mapping", and "glioma". The search focused on anatomical and surgical aspects, including indications, tools, and techniques of awake surgery in right cerebral hemisphere gliomas. The literature search identified 74 sources, including original articles, books, monographs, and review articles. Two papers reported large series of language assessment cases in 246 patients undergoing awake surgery with detailed neurological semiology and mapping techniques, while the remaining studies were predominantly neuroradiological and neuroimaging in nature. Awake craniotomy for non-dominant-hemisphere gliomas is an essential tool. The term "non-dominant" should be revised, as this hemisphere contributes significantly to essential cognitive functions in the human brain.

NOP14 as a Potential Predictor of Adult-Type Diffuse Glioma Prognosis and Immunotherapy, is Related to Cell Migration, Proliferation, and CD8+T Cell Infiltration.

World Health Organization (WHO) grade 4 adult-type diffuse glioma is the most malignant primary tumor of the brain. Nucleolar protein 14 (NOP14) is recognized to contribute significantly to the assembly of small ribosomal subunits. However, the specific involvement of NOP14 in diverse cancers remains poorly understood, particularly its role in adult-type diffuse glioma, which has yet to be elucidated. A total of 20 adult-type diffuse glioma samples with varying WHO stages were collected. The protein level of NOP14 was detected using immunohistochemistry. Additionally, NOP14 expression in LN229 and U251 cell lines and collected clinical tissue samples was quantified using the Western blot technique. Furthermore, the correlation between NOP14 and clinicopathological features, survival rates, matrix and immune scores, and immune components was investigated using data from the Cancer Gene Atlas database. NOP14 exhibited high expression in adult-type diffuse glioma patients, with the highest expression observed in the LN229 cell line. Moreover, elevated NOP14 expression was significantly correlated with poorer overall survival and demonstrated an association with unfavorable pathological features in a cohort of 703 glioblastoma (GBM) patients. Evidence of a connection between NOP14 and the tumor microenvironment was presented. Elevated NOP14 was linked to the infiltration of CD8+T cell and factors related to epithelial-mesenchymal transition. In in vitro assay, NOP14 was capable of suppressing adult-type diffuse glioma cell invasion and metastasis. NOP14 holds great promise as a candidate biomarker for detecting prognostic, molecular, and immune signatures of adult-type diffuse glioma.

Cerebrospinal Fluid Liquid Biopsies in the Evaluation of Adult Gliomas.

This review aims to discuss recent research regarding the biomolecules explored in liquid biopsies and their potential clinical uses for adult-type diffuse gliomas. Evaluation of tumor biomolecules via cerebrospinal fluid (CSF) is an emerging technology in neuro-oncology. Studies to date have already identified various circulating tumor DNA, extracellular vesicle, micro-messenger RNA and protein biomarkers of interest. These biomarkers show potential to assist in multiple avenues of central nervous system (CNS) tumor evaluation, including tumor differentiation and diagnosis, treatment selection, response assessment, detection of tumor progression, and prognosis. In addition, CSF liquid biopsies have the potential to better characterize tumor heterogeneity compared to conventional tissue collection and CNS imaging. Current imaging modalities are not sufficient to establish a definitive glioma diagnosis and repeated tissue sampling via conventional biopsy is risky, therefore, there is a great need to improve non-invasive and minimally invasive sampling methods. CSF liquid biopsies represent a promising, minimally invasive adjunct to current approaches which can provide diagnostic and prognostic information as well as aid in response assessment.

High-Grade Astrocytoma with Piloid Features: A Dual Institutional Review of Imaging Findings of a Novel Entity.

High-grade astrocytoma with piloid features (HGAP) is a recently identified brain tumor characterized by a distinct DNA methylation profile. Predominantly located in the posterior fossa of adults, HGAP is notably prevalent in individuals with neurofibromatosis type 1. We present an image-centric review of HGAP and explore the association between HGAP and neurofibromatosis type 1. Data were collected from 8 HGAP patients treated at two tertiary care institutions between January 2020 and October 2023. Demographic details, clinical records, management, and tumor molecular profiles were analyzed. Tumor characteristics, including location and imaging features on MR imaging, were reviewed. Clinical or imaging features suggestive of neurofibromatosis 1 or the presence of NF1 gene alteration were documented. The mean age at presentation was 45.5 years (male/female = 5:3). Tumors were midline, localized in the posterior fossa (n = 4), diencephalic/thalamic (n = 2), and spinal cord (n = 2). HGAP lesions were T1 hypointense, T2-hyperintense, mostly without diffusion restriction, predominantly peripheral irregular enhancement with central necrosis (n = 3) followed by mixed heterogeneous enhancement (n = 2). Two NF1 mutation carriers showed signs of neurofibromatosis type 1 before HGAP diagnosis, with one diagnosed during HGAP evaluation, strengthening the HGAP-NF1 link, particularly in patients with posterior fossa masses. All tumors were IDH1 wild-type, often with ATRX, CDKN2A/B, and NF1 gene alteration. Six patients underwent surgical resection followed by adjuvant chemoradiation. Six patients were alive, and two died during the last follow-up. Histone H3 mutations were not detected in our cohort, such as the common H3K27M typically seen in diffuse midline gliomas, linked to aggressive clinical behavior and poor prognosis. HGAP lesions may involve the brain or spine and tend to be midline or paramedian in location. Underlying neurofibromatosis type 1 diagnosis or imaging findings are important diagnostic cues.

In-house molecular diagnosis of diffuse glioma updating the revised WHO classification by a platform of the advanced medical care system, Senshin-Iryo.

Since the World Health Organization (WHO) 2016 revision, the number of molecular markers required for diffuse gliomas has increased, placing a burden on clinical practice. We have established an in-house, molecular diagnostic platform using Senshin-Iryo, a feature of Japan's unique healthcare system, and partially modified the analysis method in accordance with the WHO 2021 revision. Herein, we review over a total 5 years of achievements using this platform. Analyses of IDH, BRAF, and H3 point mutations, loss of heterozygosity (LOH) on 1p/19q and chromosomes 10 and 17, and MGMT methylation were combined into a set that was submitted to Senshin-Iryo as "Drug resistance gene testing for anticancer chemotherapy" and was approved in August 2018. Subsequently, in October 2021, Sanger sequencing for the TERT promoter mutation was added to the set, and LOH analysis was replaced with multiplex ligation-dependent probe amplification (MLPA) to analyze 1p/19q codeletion and newly required genetic markers, such as EGFR, PTEN, and CDKN2A from WHO 2021. Among the over 200 cases included, 54 were analyzed after the WHO 2021 revision. The laboratory has maintained a diagnostic platform where molecular diagnoses are confirmed within 2 weeks. Initial expenditures exceeded the income from patient copayments; however, it has gradually been reduced to running costs alone and is approaching profitability. After the WHO 2021 revision, diagnoses were confirmed using molecular markers obtained from Senshin-Iryo in 38 of 54 cases (70.1%). Among the remaining 16 patients, only four (7.4%) were diagnosed with diffuse glioma, not elsewhere classified, which was excluded in 12 cases where glioblastoma was confirmed by histopathological diagnosis. Our Senshin-Iryo trial functioned as a salvage system to overcome the transition period between continued revisions of WHO classification that has caused a clinical dilemma in the Japanese healthcare system.

Integral neuro-oncological diagnosis As the basis for personalized treatment Of brain tumors (on the example of gliomas In children)

Brain tumors are the most common group of neoplasms in children, which is in the top-3 causes of infant mortality from oncopathology. The aim of the study is to make a literature review of modern approaches to the personalization of treatment of CNS tumors in children based on the study of molecular genetics, immunohistochemical and imagingт characteristics. The article provides a description of the most common types of neoplasms of the nervous system — low grade gliomas (LGG), high grade gliomas (HGG), mixed glioneural tumors, etc. The molecular genetics, immunohistochemical, visualization characteristics of each type of gliomas are described. Modern information on prognosis and treatment of tumors is also given in the publication. The prognosis of the course of LGG/GNT in children depends more often on the patient’s age, histology, and location of the tumor, as well as its molecular profile. Older patients have a more favorable prognosis than younger children. Well-visualized tumors located superficially have a better outcome than diffuse gliomas, as well as deeply located tumors. Detection of BRAF mutations and FGFR rearrangements may indicate a better prognosis than in the presence of SNV. Local mutations of BRAF with concomitant deletion of CDKN2A, as well as mutations with H3.3 pK27 are the most dangerous.

Upregulation of HLA-II related to LAG-3+CD4+ T cell infiltration is associated with patient outcome in human glioblastoma.

Glioblastoma (GBM) is the most common malignant diffuse glioma of the brain. Although immunotherapy with immune checkpoint inhibitors (ICIs), such as programmed cell death protein (PD)-1/PD ligand-1 inhibitors, has revolutionized the treatment of several cancers, the clinical benefit in GBM patients has been limited. Lymphocyte-activation gene 3 (LAG-3) binding to human leukocyte antigen-II (HLA-II) plays an essential role in triggering CD4+ T cell exhaustion and could interfere with the efficiency of anti-PD-1 treatment; however, the value of LAG-3-HLA-II interactions in ICI immunotherapy for GBM patients has not yet been analyzed. Therefore, we aimed to investigate the expression and regulation of HLA-II in human GBM samples and the correlation with LAG-3+CD4+ T cell infiltration. Human leukocyte antigen-II was highly expressed in GBM and correlated with increased LAG-3+CD4+ T cell infiltration in the stroma. Additionally, HLA-IIHighLAG-3High was associated with worse patient survival. Increased interleukin-10 (IL-10) expression was observed in GBM, which was correlated with high levels of HLA-II and LAG-3+ T cell infiltration in stroma. HLA-IIHighIL-10High GBM associated with LAG-3+ T cells infiltration synergistically showed shorter overall survival in patients. Combined anti-LAG-3 and anti-IL-10 treatment inhibited tumor growth in a mouse brain GL261 tumor model. Invitro, CD68+ macrophages upregulated HLA-II expression in GBM cells through tumor necrosis factor-α (TNF-α). Blocking TNF-α-dependent inflammation inhibited tumor growth in a mouse GBM model. In summary, T cell-tumor cell interactions, such as LAG-3-HLA-II, could confer an immunosuppressive environment in human GBM, leading to poor prognosis in patients. Therefore, targeting the LAG-3-HLA-II interaction could be beneficial in ICI immunotherapy to improve the clinical outcome of GBM patients.

Identifying key factors for predicting O6-Methylguanine-DNA methyltransferase status in adult patients with diffuse glioma: a multimodal analysis of demographics, radiomics, and MRI by variable Vision Transformer

PurposeThis study aimed to perform multimodal analysis by vision transformer (vViT) in predicting O6-methylguanine-DNA methyl transferase (MGMT) promoter status among adult patients with diffuse glioma using demographics (sex and age), radiomic features, and MRI.MethodsThe training and test datasets contained 122 patients with 1,570 images and 30 patients with 484 images, respectively. The radiomic features were extracted from enhancing tumors (ET), necrotic tumor cores (NCR), and the peritumoral edematous/infiltrated tissues (ED) using contrast-enhanced T1-weighted images (CE-T1WI) and T2-weighted images (T2WI). The vViT had 9 sectors; 1 demographic sector, 6 radiomic sectors (CE-T1WI ET, CE-T1WI NCR, CE-T1WI ED, T2WI ET, T2WI NCR, and T2WI ED), 2 image sectors (CE-T1WI, and T2WI). Accuracy and area under the curve of receiver-operating characteristics (AUC-ROC) were calculated for the test dataset. The performance of vViT was compared with AlexNet, GoogleNet, VGG16, and ResNet by McNemar and Delong test. Permutation importance (PI) analysis with the Mann–Whitney U test was performed.ResultsThe accuracy was 0.833 (95% confidence interval [95%CI]: 0.714–0.877) and the area under the curve of receiver-operating characteristics was 0.840 (0.650–0.995) in the patient-based analysis. The vViT had higher accuracy than VGG16 and ResNet, and had higher AUC-ROC than GoogleNet (p<0.05). The ED radiomic features extracted from the T2-weighted image demonstrated the highest importance (PI=0.239, 95%CI: 0.237–0.240) among all other sectors (p<0.0001).ConclusionThe vViT is a competent deep learning model in predicting MGMT status. The ED radiomic features of the T2-weighted image demonstrated the most dominant contribution.

Comprehensive analysis of MYB/MYBL1-altered pediatric-type diffuse low-grade glioma.

Pediatric-type diffuse low-grade gliomas (pLGG) harboring recurrent genetic alterations involving MYB or MYBL1 are closely related tumors. Detailed treatment and outcome data of large cohorts are still limited. This study aimed to comprehensively evaluate pLGG with these alterations to define optimal therapeutic strategies. We retrospectively reviewed details of pLGG with MYB or MYBL1 alterations from patients treated or referred for pathologic review at St. Jude Children's Research Hospital. Tumor specimens were centrally reviewed, and clinical data were collated. Thirty-three patients (18 male; median age, 5 years) were identified. Two tumors had MYBL1 alterations; 31 had MYB alterations, MYB::QKI fusion being the most common (n = 10, 30%). Most tumors were in the cerebral hemispheres (n = 22, 67%). Two patients (6%) had metastasis at diagnosis. The median follow-up was 6.1 years. The 5-year event-free survival (EFS) rate was 81.3% ± 8.3%; the 5-year overall survival (OS) rate was 96.4% ± 4.1%. Patients receiving a near-total or gross-total resection had a 5-year EFS of 100%; those receiving a biopsy or subtotal resection had a 5-year EFS rate of 56.6% ± 15.2% (P < .01). No difference in EFS was observed based on location, histology, or molecular alterations. However, the tumors that progressed or metastasized may have distinct methylation profiles with evidence of activation of the MAPK and PI3K/AKT/mTOR pathways. pLGG with MYB/MYBL1 alterations have good outcomes. Our findings suggest that surgical resectability is a crucial determinant of EFS. Further characterization is required to identify optimal treatment strategies for progressive tumors.