bims-malgli Biomed News
on Biology of malignant gliomas
Issue of 2022‒06‒05
fourteen papers selected by
Oltea Sampetrean
Keio University

  1. Neurotherapeutics. 2022 May 31.
      Glioblastoma is the most aggressive primary brain tumor with a poor prognosis. The 2021 WHO CNS5 classification has further stressed the importance of molecular signatures in diagnosis although therapeutic breakthroughs are still lacking. In this review article, updates on the current and novel therapies in IDH-wildtype GBM will be discussed.
    Keywords:  Clinical trials; Glioblastoma; IDH-wildtype; Precision medicine; Targeted therapy
  2. JCI Insight. 2022 Jun 02. pii: e148990. [Epub ahead of print]
      Novel therapeutic strategies, including immunotherapeutics, targeting glioblastoma (GBM) often fail in the clinic, at least partly because available preclinical models in which hypotheses are being tested, do not recapitulate the human disease. To address this challenge, we took advantage of our previously developed spontaneous Qk/trp53/Pten (QPP) triple-knockout model of human GBM, and compared its immune microenvironment components with those of patient-derived tumors in effort to determine whether this model might provide an opportunity for gaining insights into tumor physiopathology as well as for preclinical evaluation of therapeutic agents. Immune profiling analyses and single-cell sequencing of implanted and spontaneous tumors from QPP mice as well as from GBM patients revealed intratumoral immune components that were predominantly myeloid cells (e.g. monocytes, macrophages, and microglia) with minor populations of T, B, and NK cells. When comparing spontaneous and implanted mouse samples, we found that there were more neutrophils, T and NK cells in the implanted model. Neutrophils, T and NK cells were increased in abundance in samples derived from human high-grade glioma (HGG) compared to those derived from low grade glioma (LGG). Overall, our data demonstrate that our implanted and spontaneous QPP models recapitulate the immunosuppressive myeloid dominant nature of the tumor microenvironment of human gliomas. Our model provides a suitable tool for investigating the complex immune compartment of gliomas and it may contribute to a better understanding of the resistance of human glioblastoma to currently available immunotherapeutics.
    Keywords:  Brain cancer; Cellular immune response; Mouse models; Neuroscience; Oncology
  3. Neuro Oncol. 2022 May 26. pii: noac143. [Epub ahead of print]
      BACKGROUND: Glioblastoma (GBM) is the most aggressive primary brain tumor. Its cellular composition is very heterogeneous, with cells exhibiting stem-cell characteristics (GSCs) that co-determine therapy resistance and tumor recurrence. Bone Morphogenetic Protein (BMP)-4 promotes astroglial and suppresses oligodendrocyte differentiation in GSCs, processes associated with superior patient prognosis. We characterized variability in cell viability of patient-derived GBM cultures in response to BMP4 and, based on single-cell transcriptome profiling, propose predictive positive and early-response markers for sensitivity to BMP4.METHODS: Cell viability was assessed in 17 BMP4-treated patient-derived GBM cultures. In two cultures, one highly sensitive to BMP4 (high therapeutic efficacy) and one with low sensitivity, response to treatment with BMP4 was characterized. We applied single-cell RNA-sequencing, analyzed the relative abundance of cell clusters, searched for and identified the aforementioned two marker types, and validated these results in all 17 cultures.
    RESULTS: High variation in cell viability was observed after treatment with BMP4. In three cultures with highest sensitivity for BMP4, a substantial new cell subpopulation formed. These cells displayed decreased cell proliferation and increased apoptosis. Neuronal differentiation was reduced most in cultures with little sensitivity for BMP4. OLIG1/2 levels were found predictive for high sensitivity to BMP4. Activation of ribosomal translation (RPL27A, RPS27) was upregulated within one day in cultures that were very sensitive to BMP4.
    CONCLUSION: The changes in composition of patient-derived GBM cultures obtained after treatment with BMP4 correlate with treatment efficacy. OLIG1/2 expression can predict this efficacy, and upregulation of RPL27A and RPS27 are useful early-response markers.
    Keywords:  BMP; drug therapy; glioblastoma; single-cell RNA-sequencing; tumor heterogeneity
  4. Oncogene. 2022 May 30.
      Glioblastoma multiforme (GBM) is the most lethal primary tumor with active neovascularization in the central nervous system. Studying the novel molecular mechanisms of GBM angiogenesis is very important. The glioblastoma-associated microglia (GAM) M2 polarization was constructed, and microglia-derived exosomes (MDEs) were isolated to co-culture with human brain microvessel endothelial cells (hBMECs). CircRNA sequence and molecular biological experiments were used to detect the expression levels and regulation functions among circKIF18A, FOXC2, ITGB3, CXCR4, DLL4 and the PI3K/AKT signaling. The functional effects of silencing or overexpression of these molecules were evaluated in hBMECs viability, invasion, and tube formation in vitro and tumorigenicity in vivo. M2 microglia polarization is positively correlated with microvessels' density in GBM patients. M2 GAM can promote the angiogenesis of GBM via transporting exosomal circKIF18A into hBMECs. Mechanistically, circKIF18A can bind to, maintain the stability and nuclear translocation of FOXC2 in hBMECs. Furtherly, as a transcription factor, FOXC2 can directly bind to the promoter of ITGB3, CXCR4, and DLL4 and upregulate their expressions. Besides, FOXC2 can also activate the PI3K/AKT signaling and promote the angiogenesis of GBM. Our study identified a novel molecular mechanism for M2 GAM-derived exosomal circKIF18A participating in GBM angiogenesis via targeting FOXC2. This may provide a novel treatment target to improve the outcomes for anti-angiogenic therapies in GBM.
  5. Cell. 2022 May 24. pii: S0092-8674(22)00536-0. [Epub ahead of print]
    GLASS Consortium
      The factors driving therapy resistance in diffuse glioma remain poorly understood. To identify treatment-associated cellular and genetic changes, we analyzed RNA and/or DNA sequencing data from the temporally separated tumor pairs of 304 adult patients with isocitrate dehydrogenase (IDH)-wild-type and IDH-mutant glioma. Tumors recurred in distinct manners that were dependent on IDH mutation status and attributable to changes in histological feature composition, somatic alterations, and microenvironment interactions. Hypermutation and acquired CDKN2A deletions were associated with an increase in proliferating neoplastic cells at recurrence in both glioma subtypes, reflecting active tumor growth. IDH-wild-type tumors were more invasive at recurrence, and their neoplastic cells exhibited increased expression of neuronal signaling programs that reflected a possible role for neuronal interactions in promoting glioma progression. Mesenchymal transition was associated with the presence of a myeloid cell state defined by specific ligand-receptor interactions with neoplastic cells. Collectively, these recurrence-associated phenotypes represent potential targets to alter disease progression.
    Keywords:  genomics; glioblastoma; glioma; hypermutation; macrophages; microenvironment; neurons; single-cell; spatial imaging; treatment resistance
  6. Elife. 2022 Jun 01. pii: e78972. [Epub ahead of print]11
      Cancer stem cells (CSCs) alone can initiate and maintain tumors, but the function of non-cancer stem cells (non-CSCs) that form the tumor bulk remains poorly understood. Proteomic analysis showed a higher abundance of the extracellular matrix small leucine-rich proteoglycan Fibromodulin (FMOD) in the conditioned medium of differentiated glioma cells (DGCs), the equivalent of glioma non-CSCs, compared to that of glioma stem-like cells (GSCs). DGCs silenced for FMOD fail to cooperate with co-implanted GSCs to promote tumor growth. FMOD downregulation neither affects GSC growth and differentiation nor DGC growth and reprogramming in vitro. DGC-secreted FMOD promotes angiogenesis by activating Integrin-dependent Notch signaling in endothelial cells. Furthermore, conditional silencing of FMOD in newly generated DGCs in vivo inhibits the growth of GSC-initiated tumors due to poorly developed vasculature and increases mouse survival. Collectively, these findings demonstrate that DGC-secreted FMOD promotes glioma tumor angiogenesis and growth through paracrine signaling in endothelial cells and identifies a DGC-produced protein as a potential therapeutic target in glioma.
    Keywords:  cancer biology; human; mouse
  7. iScience. 2022 Jun 17. 25(6): 104398
      Diffuse midline gliomas (DMG) are highly malignant incurable pediatric brain tumors. In this study, we show that Aurora kinase A (AURKA) is overexpressed in DMG and can be used as a therapeutic target. Additionally, AURKA inhibition combined with CRISPR/Cas9 screening in DMG cells, revealed polo-like kinase 1 (PLK1) as a synergistic target with AURKA. Using a panel of patient-derived DMG culture models, we demonstrate that treatment with volasertib, a clinically relevant and selective PLK1 inhibitor, synergizes with different AURKA inhibitors, supporting the CRISPR screen results. Mechanistically, our results show that combined loss of PLK1 and AURKA causes a G2/M cell cycle arrest which blocks vital parts of DNA-damage repair and induces apoptosis, solely in DMG cells. Altogether, our findings highlight the importance of AURKA and PLK1 for DMG propagation and demonstrate the potential of concurrently targeting these proteins as a therapeutic strategy for these devastating pediatric brain tumors.
    Keywords:  Biological sciences; Cancer; Cell biology; Molecular biology
  8. Cancer Sci. 2022 Jun 03.
      Lysosomes function as the digestive system of a cell, which are involved in macromolecular recycling, vesicle trafficking, metabolic reprogramming, and pro-growth signaling. Although quality control of lysosome biogenesis is thought to be a potential target for cancer therapy, practical strategies have not been established. Here, we show that lysosomal membrane integrity supported by lysophagy, a selective autophagy for damaged lysosomes, is a promising therapeutic target for glioblastoma (GBM). In this study, we found that ifenprodil, an FDA-approved drug with neuromodulatory activities, efficiently inhibited spheroid formation of patient-derived GBM cells in a combination with autophagy inhibition. Ifenprodil increased intracellular Ca2+ level, resulting in mitochondrial reactive oxygen species-mediated cytotoxicity. The ifenprodil-induced Ca2+ elevation was due to Ca2+ release from lysosomes, but not endoplasmic reticulum, associated with galectin-3 punctation as an indicator of lysosomal membrane damage. Since the Ca2+ release was enhanced by ATG5 deficiency, autophagy protected against lysosomal membrane damage. By comparative analysis of 765 FDA-approved compounds, we identified another clinically available drug for CNS diseases, amoxapine, in addition to ifenprodil. Both compounds promoted degradation of lysosomal membrane proteins, indicating a critical role of lysophagy in quality control of lysosomal membrane integrity. Importantly, a synergistic inhibitory effect of ifenprodil and chloroquine, a clinically available autophagy inhibitor, on spheroid formation was remarkable in GBM cells, but not in non-transformed neural progenitor cells. Finally, chloroquine dramatically enhanced effects of the compounds inducing lysosomal membrane damage in a patient-derived xenograft model. These data demonstrate a therapeutic advantage of targeting lysosomal membrane integrity in GBM.
    Keywords:  Lysosomal membrane turnover; autophagy; calcium; glioblastoma; lysosomal membrane integrity
  9. STAR Protoc. 2022 Jun 17. 3(2): 101357
      Here, we present a mass cytometry protocol optimized to examine the phenotype of immune cells within the mouse glioma microenvironment, using a Sleeping Beauty transposon-mediated mouse glioma model. We describe antibody conjugation and titrations for analysis of immune cells. We then detail mouse brain tumor tissue collection and processing, staining, followed by data acquisition, analysis, and gating strategy. This protocol can be applied to any brain tumor-harboring mouse model. For complete details on the use and execution of this protocol, please refer to Alghamri et al. (2021).
    Keywords:  Antibody; Cancer; Cell Biology; Flow Cytometry/Mass Cytometry; Immunology; Model Organisms; Neuroscience; Single Cell
  10. iScience. 2022 Jun 17. 25(6): 104395
      Oncolytic viruses (OVs) are emerging cancer immunotherapy. Despite notable successes in the treatment of some tumors, OV therapy for central nervous system cancers has failed to show efficacy. We used an ex vivo tumor model developed from human glioblastoma tissue to evaluate the infiltration of herpes simplex OV rQNestin (oHSV-1) into glioblastoma tumors. We next leveraged our data to develop a computational, model of glioblastoma dynamics that accounts for cellular interactions within the tumor. Using our computational model, we found that low stromal density was highly predictive of oHSV-1 therapeutic success, suggesting that the efficacy of oHSV-1 in glioblastoma may be determined by stromal-to-tumor cell regional density. We validated these findings in heterogenous patient samples from brain metastatic adenocarcinoma. Our integrated modeling strategy can be applied to suggest mechanisms of therapeutic responses for central nervous system cancers and to facilitate the successful translation of OVs into the clinic.
    Keywords:  Cancer; Computational bioinformatics; Immunology
  11. Proc Natl Acad Sci U S A. 2022 Jun 07. 119(23): e2118697119
      Significance The blood-brain barrier represents a major therapeutic challenge for the treatment of glioblastoma, and there is an unmet need for in vitro models that recapitulate human biology and are predictive of in vivo response. Here, we present a microfluidic model of vascularized glioblastoma featuring a tumor spheroid in direct contact with self-assembled vascular networks comprising human endothelial cells, astrocytes, and pericytes. This model was designed to accelerate the development of targeted nanotherapeutics and enabled rigorous assessment of a panel of surface-functionalized nanoparticles designed to exploit a receptor overexpressed in tumor-associated vasculature. Trafficking and efficacy data in the in vitro model compared favorably to parallel in vivo data, highlighting the utility of the vascularized glioblastoma model for therapeutic development.
    Keywords:  blood–brain barrier; drug delivery; glioblastoma; microfluidic; nanoparticle
  12. Acta Neuropathol Commun. 2022 May 31. 10(1): 80
      The majority of diffuse midline gliomas, H3 K27-altered (DMG-H3 K27-a), are infiltrating pediatric brain tumors that arise in the pons with no effective treatment. To understand how clonal evolution contributes to the tumor's invasive spread, we performed exome sequencing and SNP array profiling on 49 multi-region autopsy samples from 11 patients with pontine DMG-H3 K27-a enrolled in a phase I clinical trial of PDGFR inhibitor crenolanib. For each patient, a phylogenetic tree was constructed by testing multiple possible clonal evolution models to select the one consistent with somatic mutations and copy number variations across all tumor regions. The tree was then used to deconvolute subclonal composition and prevalence at each tumor region to study convergent evolution and invasion patterns. Somatic variants in the PI3K pathway, a late event, are enriched in our cohort, affecting 70% of patients. Convergent evolution of PI3K at distinct phylogenetic branches was detected in 40% of the patients. 24 (~ 50%) of tumor regions were occupied by subclones of mixed lineages with varying molecular ages, indicating multiple waves of invasion across the pons and extrapontine. Subclones harboring a PDGFRA amplicon, including one that amplified a PDGRFAY849C mutant allele, were detected in four patients; their presence in extrapontine tumor and normal brain samples imply their involvement in extrapontine invasion. Our study expands the current knowledge on tumor invasion patterns in DMG-H3 K27-a, which may inform the design of future clinical trials.
  13. Cancer Immunol Immunother. 2022 Jun 03.
      Lactic acidosis has been reported in solid tumor microenvironment (TME) including glioblastoma (GBM). In TME, several signaling molecules, growth factors and metabolites have been identified to induce resistance to chemotherapy and to sustain immune escape. In the early phases of the disease, microglia infiltrates TME, contributing to tumorigenesis rather than counteracting its growth. Insulin-like Growth Factor Binding Protein 6 (IGFBP6) is expressed during tumor development, and it is involved in migration, immune-escape and inflammation, thus providing an attractive target for GBM therapy. Here, we aimed at investigating the crosstalk between lactate metabolism and IGFBP6 in TME and GBM progression. Our results show that microglia exposed to lactate or IGFBP6 significantly increased the Monocarboxylate transporter 1 (MCT1) expression together with genes involved in mitochondrial metabolism. We, also, observed an increase in the M2 markers and a reduction of inducible nitric oxide synthase (iNOS) levels, suggesting a role of lactate/IGFBP6 metabolism in immune-escape activation. GBM cells exposed to lactate also showed increased levels of IGFBP6 and vice-versa. Such a phenomenon was coupled with a IGFBP6-mediated sonic hedgehog (SHH) ignaling increase. We, finally, tested our hypothesis in a GBM zebrafish animal model, where we observed an increase in microglia cells and igfbp6 gene expression after lactate exposure. Our results were confirmed by the analysis of human transcriptomes datasets and immunohistochemical assay from human GBM biopsies, suggesting the existence of a lactate/IGFBP6 crosstalk in microglial cells, so that IGFBP6 expression is regulated by lactate production in GBM cells and in turn modulates microglia polarization.
    Keywords:  Glioblastoma; IGFBP6; Lactate; Microenvironment; Microglia
  14. Neuro Oncol. 2022 May 25. pii: noac139. [Epub ahead of print]
      BACKGROUND: Olutasidenib (FT2102) is a highly potent, orally bioavailable, brain-penetrant and selective inhibitor of mutant isocitrate dehydrogenase 1 (IDH1). The aim of the study was to determine the safety and clinical activity of olutasidenib in patients with relapsed/refractory gliomas harboring an IDH1  R132X mutation.METHODS: This was an open-label, multicenter, non-randomized, phase 1b/2 clinical trial. Eligible patients (≥18 years) had histologically confirmed IDH1  R132Xmutated glioma that relapsed or progressed on or following standard therapy and had measurable disease. Patients received olutasidenib, 150 mg orally twice daily (BID) in continuous 28-day cycles. The primary endpoints were dose-limiting toxicities (DLTs) (cycle 1) and safety in phase 1 and objective response rate using the Modified Response Assessment in Neuro-Oncology criteria in phase 2.
    RESULTS: Twenty-six patients were enrolled and followed for a median 15.1 months (7.3‒19.4). No DLTs were observed in the single-agent glioma cohort and the pharmacokinetic relationship supported olutasidenib 150 mg BID as the recommended phase 2 dose. In the response-evaluable population, disease control rate (objective response plus stable disease) was 48%. Two (8%) patients demonstrated a best response of partial response and eight (32%) had stable disease for at least 4 months. Grade 3‒4 adverse events (≥10%) included alanine aminotransferase increased and aspartate aminotransferase increased (three [12%], each).
    CONCLUSIONS: Olutasidenib 150 mg BID was well tolerated in patients with relapsed/refractory gliomas harboring an IDH1  R132X mutation and demonstrated preliminary evidence of clinical activity in this heavily pretreated population.
    Keywords:  Glioma; brain penetration; mutant IDH1; olutasidenib