bims-malgli Biomed News
on Biology of malignant gliomas
Issue of 2026–06–07
twelve papers selected by
Oltea Sampetrean, Keio University



  1. Cancer Discov. 2026 Jun 01. 16(6): 1047-1049
      Glioblastoma (GBM) cells secrete C1QL1, which binds BAI3 on nearby neurons and tumor cells to activate RAC1, promoting tumor microtube growth, malignant synapse formation, and remodeling of normal synapses. Blocking RAC1 with a targeted inhibitor disrupts this process and may help prevent GBM recurrence. See related article by Ding et al., p. 1176.
    DOI:  https://doi.org/10.1158/2159-8290.CD-26-0608
  2. Neuro Oncol. 2026 May 29. pii: noag131. [Epub ahead of print]
       BACKGROUND: Glioblastoma (GBM) is the most common primary malignant brain tumor. The aim of this study was to elucidate the role of microenvironment and intrinsic T-type calcium channels (Cav3) in regulating GBM.
    METHODS: We grafted syngeneic GBM cells into Cav3.2 knockout mice to assess the role of microenvironment T-Type calcium channels on GBM growth. We grafted syngeneic GBM cells into the hippocampus along Schafer collaterals and performed electrophysiology. We used neurons from WT and Cav3.2 Knockout (KO) mice in co-culture with GBM stem cells (GSC) to assess the effects of Cav3.2 on neuron/GSC synaptic connections and tumor cell growth. We performed single-cell RNA-seq of tumors from WT and Cav3.2 KO mice to elucidate the regulation of tumors by the microenvironment.
    RESULTS: Cav3.2KO in the microenvironment led to significant reduction of GBM growth and prolongation of animal survival. Neuronal Cav3.2 promoted GSC growth in co-culture and neuron/GBM functional synaptic connections in vivo. scRNA-seq showed that microenvironment Cav3.2 regulates neuronal and glial biological processes. Microenvironment Cav3.2 downregulated numerous genes associated with regulating the OPC cell state in GBM tumors. Treatment of GSCs with the Cav3 blocker mibefradil downregulated genes associated with neuronal processes. The Cav3 blocker drug mibefradil synergized with temozolomide (TMZ) and radiation to reduce in vivo tumor growth and prolong animal survival.
    CONCLUSIONS: The data reveal a role for microenvironment Cav3 in promoting GBM progression through regulating neuronal and glial processes. Targeting both intrinsic and microenvironment Cav3 with the inhibitor mibefradil significantly enhanced the anti-GBM effects of TMZ and radiation.
    DOI:  https://doi.org/10.1093/neuonc/noag131
  3. Front Oncol. 2026 ;16 1803705
      Gliomas represent some of the most lethal and biologically complex tumors of the central nervous system, with poor outcomes across both adult and pediatric populations. Beyond tumor-intrinsic genetic alterations, glioma progression is increasingly recognized to be driven by dynamic interactions with the neural microenvironment, particularly through direct tumor-neuron communication. Studies of adult and pediatric gliomas, including glioblastoma (GBM) and diffuse midline glioma (DMG), using single-cell profiling and multi-omics technologies have revealed extensive tumor intrinsic and extrinsic heterogeneity, with phenotypically and genetically plastic tumor cells actively engaged with neurons, glia, vasculature, and immune compartments that collectively reshape the neural microenvironment to promote tumor growth, invasion, and therapy resistance. Conventional two-dimensional in vitro culture systems and in vivo animal models incompletely recapitulate these interactions, limiting mechanistic insights and constraining clinical translation to human patients. Recent advances in organoid technologies have addressed this gap, enabling the development of three-dimensional human-specific models of glioma-microenvironment interactions. Platforms such as iPSC-derived cerebral organoids, regionally patterned neural organoids, patient-derived glioma organoids and tumor-organoid co-culture systems capture essential features of these human diseases. These systems recapitulate tumor-neuron synaptic integration, diffuse invasion programs, activity-dependent tumor growth, hypoxia-structured niches, vascular interactions, and patient-specific therapeutic responses. In this review, we synthesize recent advances and biological insights gleaned across glioma organoid model systems and evaluate their strengths and limitations, including neurovascular and multi-lineage systems. We further highlight emerging innovations that enhance the physiological fidelity, reproducibility, and scalability of these models. Collectively, these platforms establish tumor microenvironment interactions as a central organizing principle of glioma biology and provide a strong foundation for mechanistic discovery, therapeutic development, and personalized neuro-oncology.
    Keywords:  brain organoids; cancer therapy; glioblastoma; glioma; glioma organoids; tumor invasion; tumor microenvironment; tumor synapse
    DOI:  https://doi.org/10.3389/fonc.2026.1803705
  4. J Clin Invest. 2026 Jun 02. pii: e199228. [Epub ahead of print]
      Glioblastoma, IDH-wildtype (GBM, WHO grade 4) is the most common malignant glioma in adults and is characterized by a hypoxic and immunosuppressive tumor microenvironment (TME). Bone marrow-derived tumor-associated macrophages (TAMs) dominate the immune landscape in GBM and are recruited to the peri-necrotic niche following the onset of necrosis. CLEC5A has the strongest association with poor clinical outcome among immune-related genes in GBM, and is preferentially expressed in hypoxic, peri-necrotic TAMs. CLEC5A overexpression promotes TAM polarization toward an immunosuppressive phenotype, and secretion of immunoregulatory cytokines. Using an RCAS/tv-a GBM model with bone marrow transplantation from Clec5a-/- donor mice, we demonstrated that CLEC5A loss prolongs survival, delays tumor progression, and attenuates TME immunosuppression. Mechanistically, podoplanin (PDPN) expressed on glioma cells directly engages CLEC5A and triggers downstream Syk-JAK-STAT3 signaling in TAMs. Pharmacologic Syk inhibition suppresses glioma growth, diminishes TAM infiltration and polarization, reverses the immunosuppressive TME, and prolongs survival in vivo. Collectively, our findings indicate that the PDPN-CLEC5A-Syk-STAT3 axis orchestrates TAM polarization and TME immunosuppression in the peri-necrotic niche of GBM, highlighting CLEC5A/Syk as a promising therapeutic target for reversing the immunosuppressive TME and improving outcomes.
    Keywords:  Brain cancer; Hypoxia; Macrophages; Neuroscience; Oncology
    DOI:  https://doi.org/10.1172/JCI199228
  5. Sci Rep. 2026 Jun 02.
      Glioma is a common malignant tumor of the central nervous system associated with poor prognosis, highlighting the urgent need for novel tumor suppressors. Here, we identify SERPINI1 (a serpini family member) as a tumor suppressor in glioma, with a focus on glioblastoma (GBM). Integrative analysis of TCGA, GEO, and CGGA datasets demonstrated downregulation of SERPINI1 in glioma versus normal brain tissues, with lower SERPINI1 expression associated with higher tumor grade and worse clinical outcomes. Functional assays showed that SERPINI1 suppresses glioma cell proliferation, migration, and invasion of GBM cells. Mechanistically, IP-mass spectrometry identified 167 SERPINI1-interacting proteins, including VRK1 and VRK3, which are involved in critical oncogenic pathways. Key interactions were validated by co-IP and Western blot, as well as by immunofluorescence co-localization assays. Furthermore, structural prediction demonstrated that SERPINI1 specifically targets the catalytic domain of VRK1/VRK3, potentially modulating their activity. Our findings establish SERPINI1 as a novel tumor suppressor in GBM and highlight its regulatory network as a potential therapeutic target.
    Keywords:  Glioma; SERPINI1; Tumor suppressor gene; VRK1; VRK3
    DOI:  https://doi.org/10.1038/s41598-026-55196-3
  6. Cell Rep. 2026 Jun 01. pii: S2211-1247(26)00486-9. [Epub ahead of print]45(6): 117408
      R-loop remodeling dynamically regulates chromatin states and gene expression; however, its exploitation by cancer to sustain self-renewal and malignancy remains poorly understood. Here, we find that glioblastoma (GBM) stem cells (GSCs) display highly active R-loops compared to differentiated progeny and neural stem cells. Genome-wide mapping reveals cell-specific enrichment and spatial accumulation of R-loops at promoter-proximal regions in GSCs, correlating with active transcription and open chromatin. We identify N-acetyltransferase 10 (NAT10) as a high-affinity R-loop-binding protein in GSCs, where it is overexpressed downstream of OLIG1. NAT10 catalyzes widespread N4-acetylcytidine (ac4C) deposition on the RNA strand of R-loops, stabilizing promoter-associated R-loops and facilitating open chromatin to sustain self-renewal through core stemness regulators, including EGR1. NAT10 knockdown suppresses GSC proliferation and maintenance in vitro and attenuates tumor growth in vivo. Pharmacological inhibition of NAT10/ac4C-modified R-loops using remodelin phenocopies NAT10 genetic targeting, demonstrating therapeutic promise for targeting cancer.
    Keywords:  CP: cancer; CP: neuroscience; EGR1; NAT10; R-loop remodelin; ac(4)C; cancer stem cell; epitranscriptomics; glioblastoma; glioblastoma stem cell
    DOI:  https://doi.org/10.1016/j.celrep.2026.117408
  7. Nat Cancer. 2026 Jun 03.
      The determinants of immune checkpoint blockade (ICB) response in glioblastoma (GBM) with wild-type isocitrate dehydrogenase remain poorly understood. Here we profiled 181 ICB-treated GBM samples with bulk DNA sequencing, bulk RNA sequencing and single-nucleus RNA sequencing to investigate the genomic features associated with ICB outcomes. Baseline tumor transcriptional subtype was predictive of overall survival following ICB, with mesenchymal (MES) GBM associated with improved outcomes to ICB but not standard chemoradiation. Non-MES-associated genetic lesions, including those in PDGFRA and CDKN2A, were associated with worse survival following ICB but not standard therapy. Tumor mutational burden was not predictive of outcomes. Survival was associated with pre-ICB enrichment for MES-like malignant cells, marked by high human leukocyte antigen class I expression and greater T cell infiltration. Paired tumor analyses linked ICB exposure to outgrowth of subclones harboring lesions associated with non-MES subtypes, supporting MES-to-non-MES transition as a common trajectory of acquired resistance to ICB, distinct from standard chemoradiation.
    DOI:  https://doi.org/10.1038/s43018-026-01179-2
  8. Nat Med. 2026 Jun 01.
      Glioblastoma (GBM) is an immunologically cold brain tumor with poor outcome, characterized by a myeloid-driven immunosuppressive microenvironment. Here we report an interim analysis of a first-in-human phase 1/2a dose-escalation study evaluating Temferon-a genetically engineered autologous stem cell transplant designed to deliver interferon-α2 by means of myeloid progeny recruited to the GBM TME and locally activate antitumor immunity. Twenty-four newly diagnosed patients with GBM and unmethylated MGMT promoter were treated across eight cohorts following surgical resection and radiotherapy, testing Temferon doses ranging from 0.5 × 106 to 4.0 × 106 CD34+ cells kg-1 and different conditioning regimens (BCNU or busulfan, with or without thiotepa). The primary endpoint was safety and tolerability within 90 days after infusion. Secondary endpoints included long-term safety, dose and conditioning regimen selection, Temferon engraftment, clinical response, quality of life and survival. No dose-limiting toxicities were observed up to the highest dose level of temferon tested. Busulfan conditioning was selected for further development. Adverse events included laboratory abnormalities, cytopenias and infections consistent with autologous stem cell transplant. Median overall survival and progression-free survival were 16.7 months and 8.1 months from diagnosis, respectively, with most patients maintaining good performance status and quality of life. Genetically engineered cells were detected long term in the bone marrow and the blood, where minimal amounts of interferon-α were measured. Temferon is a safe and tolerable immunotherapeutic strategy in patients with newly diagnosed GBM. ClinicalTrials.gov: NCT03866109 .
    DOI:  https://doi.org/10.1038/s41591-026-04419-1
  9. Sci Rep. 2026 Jun 03.
      The evolution of glioblastoma (GBM) is coupled with a proneural-to-mesenchymal transition (PMT) that exacerbates disease in part through heightened cell invasiveness and spread. PMT follows similar molecular and phenotypic features with epithelial to mesenchymal transitions (EMT) and promotes rapid GBM invasion despite tight physical barriers in the dense brain parenchyma. Recent studies suggest that efficient confined migration is key to navigating these physical constraints; however, the role of PMT in mediating rapid confined migration remain unclear. Using microchannel platforms, AFM, and molecular assays, we explore this question through a biophysical lens to investigate the impact of GBM mesenchymal transformation on cellular mechanics and confined migration. We found that TGF-β1 induced PMT decreased expression and organization of Lamin A, leading to a reduction in nuclear stiffness, especially in U251 cells (1278 Pa → 682.6 Pa). Mesenchymal U251s migrated more quickly through confined microchannels though mesenchymal U87s migrated more slowly. Notably, nuclear stiffening via RO-3306 dramatically reduced confined migration speed in TGF-β1 treated U251 cells. Our study reveals that TGF-β1 induced PMT reduces Lamin A expression and softens the nucleus to support efficient confined migration in a cell-type dependent manner. These findings indicate that PMT alters the biophysical properties of the cell, opening new directions for developing therapeutic strategies for this deadly disease.
    Keywords:  Biophysical properties; Confined migration; Glioblastoma; Nuclear mechanics
    DOI:  https://doi.org/10.1038/s41598-026-56141-0
  10. Cell Death Dis. 2026 May 30. pii: 517. [Epub ahead of print]17(1):
      Diffuse midline glioma, H3K27-altered (DMG), is an aggressive and uniformly fatal paediatric brain tumour arising in midline structures and characterised by substantial microglial infiltration. We investigated whether microglia adopt a reactive state in response to DMG cells that functionally contributes to tumour progression. Transcriptomic profiling of microglia exposed to DMG, H3K27M cells, together with analysis of tumour associated myeloid cells isolated from DMG patient biopsies, revealed a pronounced upregulation of extracellular matrix (ECM) components, including fibronectin. Single cell transcriptomic analysis further identified microglia as the primary fibronectin expressing cell population within human DMG, H3K27M tumours. Functional invasion assays using a panel of patient-derived DMG, H3K27M cells, revealed that microglia-derived fibronectin significantly enhances tumour cell invasiveness, while its chemical inhibition with RGDS peptide or Avapritinib or its genetic silencing using small-interfering RNAs effectively suppresses invasion. Across independent patient cohorts (Kids First, PNOC, and CBTTC), and in archival tissues, DMG tumours were found to exhibit elevated expression of ECM components, and high fibronectin expression that correlated with poor prognosis. These findings suggest that microglia actively contribute to DMG invasiveness through ECM component production, identifying fibronectin as a potential therapeutic target in this lethal paediatric cancer.
    DOI:  https://doi.org/10.1038/s41419-026-08891-y
  11. bioRxiv. 2026 May 19. pii: 2026.05.14.725183. [Epub ahead of print]
      Oligodendroglioma is a primary central nervous system tumor classified by the presence of isocitrate dehydrogenase (IDH) mutations and codeletion of 1p/19q. Here we describe the generation of an IDH-mutant 1p/19q-codeleted oligodendroglioma mouse model using in utero electroporation. We identified IDH1 R132H , PIK3CA E545K , Cic KO , Fubp1 KO and Cdkn2a KO as the optimal combination (termed Oligo Cdkn2a ) to drive fully penetrant tumors that histologically resemble human grade II/III IDH-mutant, 1p/19q-codeleted oligodendroglioma. Replacing Cdkn2a with Trp53 loss in this mouse model shifted tumor histology towards high grade astrocytoma. Oligo Cdkn2a tumors displayed metabolic and transcriptional changes associated with IDH and CIC mutations, and single cell sequencing identified a bias towards oligodendrocyte differentiation compared to an IDH wild-type glioblastoma mouse model. Oligo Cdkn2a tumors represent the first mouse model system to recapitulate the genetic, histological and transcriptional features of human IDH-mutant 1p/19q-codeleted oligodendrogliomas, offering a platform to further dissect tumor biology and test new therapeutic strategies.
    DOI:  https://doi.org/10.64898/2026.05.14.725183
  12. Nature. 2026 Jun 03.
      Gliomas with mutant isocitrate dehydrogenase (IDH) are malignant brain tumours that typically arise in early to mid-adulthood and nearly always recur following treatment1,2. However, the genetic and cellular-state changes that drive IDH-mutant glioma progression under treatment remain incompletely understood. Here we integrated single-nucleus transcriptomic profiles, chromatin accessibility profiles and bulk DNA and RNA sequencing from 75 temporally separated gliomas across 35 patients comprising both the oligodendroglioma and astrocytoma IDH-mutant glioma tumour types. We show that malignant cell states transcriptionally resemble stages of normal glial-neuronal lineage development or a reactive mesenchymal-like state, mirroring states previously described in IDH wild-type glioblastoma3,4. Malignant cell states displayed distinct chromatin accessibility profiles that were comparable between both IDH-mutant glioma types. The abundance of less differentiated malignant cells increased with grade and with genetic alterations such as PDGFRA amplification. Longitudinal analysis highlighted two major malignant cell-state transition patterns. First, reduced lineage differentiation and increased proliferative malignant cells at recurrence were enriched in gliomas that acquired recurrence-associated genetic events. These included treatment-associated hypermutation, increased copy number changes and cell cycle alterations. Second, increased mesenchymal-like-state abundance occurred independently of acquired genetic alterations and instead coincided with elevated macrophage expression. Overall, our findings provide an integrative model that traces the cell intrinsic and extrinsic factors that shape cellular states during IDH-mutant glioma disease progression.
    DOI:  https://doi.org/10.1038/s41586-026-10612-6