bims-malgli 2025-09-21 papers

bims-malgli

Biomed News

on Biology of malignant gliomas

Issue of 2025–09–21
fifteen papers selected by
Oltea Sampetrean, Keio University

Co-activation of super-enhancer complex SOX2 and HDAC1 confers temozolomide resistance by promoting PDGFB transcription in glioblastoma.
Extracellular Matrix Stiffness Conditions Glioblastoma Cells for Long-term Migration: Mechanical Memory as a Driver of Invasion and Recurrence in Glioblastoma.
Dual checkpoint blockade of glioblastoma with Anti-PD-1 and Anti-LAG-3 promotes expansion of tumor-reactive T cell clones along a unique pathway of differentiation.
Multiple patient-derived glioblastoma models reveal synthetic lethality through concurrent PI3K and CDK4/6 inhibition by blocking trans-active cooperation.
Understanding and imaging PHGDH-driven intrinsic resistance to mutant IDH inhibition in gliomas.
Single-cell profiling of peripheral and local immune compartments reveal unique genotype-independent prognostic immune signatures across IDH-stratified glioma.
Restraint of cancer cell plasticity by spatial homotypic clustering.
Transcriptomics-Guided High-Throughput Drug Screening Identifies Potent Therapies for P53 Pathway Alterated DIPG/DMG.
Wnt inhibition alleviates resistance to anti-PD1 therapy and improves antitumor immunity in glioblastoma.
EGFR/ZBED1 reciprocal regulation promotes stemness and tumorigenesis in glioblastoma.
Spatial transcriptomic analysis reveals lack of response to PD-1 blockade in recurrent glioblastoma.
Quantitative Cell Type Specific Immunopeptidome Analysis of Macrophage and Tumor Co-evolution Reveals Therapeutic MHC-I Peptides in Glioblastoma.
Preclinical efficacy of combinatorial B7-H3 CAR T cells and ONC206 against diffuse intrinsic pontine glioma.
Connexin 43 drives glioblastoma cancer stem cell phenotypes through a WNK lysine-deficient protein kinase 1-c-MYC signaling axis.
A spatial map of MAPK-activated immunosuppressive myeloid populations in pediatric low-grade glioma.

Neuro Oncol. 2025 Sep 15. pii: noaf219. [Epub ahead of print]

Co-activation of super-enhancer complex SOX2 and HDAC1 confers temozolomide resistance by promoting PDGFB transcription in glioblastoma.

Han Xie, Tongjie Ji, Chunyu Zhang, Meng Cheng, Rui Wang, Yueyao Wu, Jingzhe Wang, Honghao Wang, Junyu Yang, Siyi Xu, Min Liu, Jing Zhang, Chunlong Zhong.

   BACKGROUND: Temozolomide (TMZ) resistance remains the major obstacle in the treatment of glioblastoma (GBM). We previously found that the super-enhancer (SE) complex is involved in the regulation of genes related to tumor biology, but its mechanisms in mediating TMZ resistance in GBM remain poorly characterized.
METHODS: Comprehensive in vitro and in vivo functional experiments were conducted using patient-derived cells (PDCs), patient-derived organoids, and PDCs xenograft models. Cleavage Under Targets and Tagmentation, chromatin immunoprecipitation, co-immunoprecipitation, mass spectrometry, protein fragment complementation assay, dual-luciferase reporter assay, fluorescence polarization assay, and surface plasmon resonance assay were employed to unravel the molecular mechanisms.
RESULTS: We found that SOX2 is significantly upregulated in TMZ-resistant PDCs and associated with the poor prognosis of recurrent GBM patients. Moreover, inhibition of SOX2 enhanced TMZ-induced apoptosis and DNA damage response, thereby promoting TMZ chemosensitivity. Mechanically, we identified PDGFB as a novel SE-associated oncogene mediated by SOX2. SE complex SOX2 and HDAC1 were recruited together to the SE region of PDGFB, synergistically triggering the PDGFB-MAPK/PI3K signaling axis and ultimately promoting TMZ resistance. Notably, virtual screening targeting the critical interaction domain between SOX2 and HDAC1 identified the FDA-approved drug fluvastatin as a potent SOX2 inhibitor that effectively sensitizes GBM cells to TMZ.
CONCLUSIONS: Targeting the SE complex enhances TMZ chemosensitivity in GBM, providing a promising therapeutic avenue to overcome drug resistance and improve clinical outcomes.

Keywords:  PDGFB; SOX2; glioblastoma; super-enhancer complex; temozolomide resistance

DOI:  https://doi.org/10.1093/neuonc/noaf219
Neuro Oncol. 2025 Sep 17. pii: noaf205. [Epub ahead of print]

Extracellular Matrix Stiffness Conditions Glioblastoma Cells for Long-term Migration: Mechanical Memory as a Driver of Invasion and Recurrence in Glioblastoma.

Paola Suarez-Meade, Rachel Whitehead, Steve Rosenfeld, Paula Schiapparelli, Konstantinos Konstantopoulos, Alfredo Quinones-Hinojosa.

  Extracellular matrix (ECM) stiffening correlates with tumor invasion in various cancer types, including glioblastoma (GBM). Increased matrix stiffness promotes a migratory phenotype through dysregulation of cell-ECM bidirectional communication. Exposure to stiffer environments is sensed by cells, which then adapt in ways that promote invasive behavior. These adaptive changes are imprinted onto the cells and persist even after they are placed in new, softer microenvironments via a process known as "mechanical memory". Mechanical memory is believed to be driven by mechanosensitive transcription factor activity and epigenetic remodeling. Glioblastoma (GBM) recurrence is linked to the ability of cells to disperse and infiltrate the surrounding healthy tissue. ECM stiffness in GBM is heterogeneous; it starts with a softer tumor core and becomes progressively stiffer towards the tumor's edges, potentially promoting sustained tumor invasion through mechanical memory. This review discusses the role of ECM stiffness in cancer cell behavior and the implications of ECM stiffening in GBM. We then describe the findings associated with mechanical memory and relay underlying mechanisms currently understood to drive the preservation of mechanically primed phenotypes. Lastly, we discuss how matrix stiffness can drive migratory phenotypes in GBM cells and the potential role that progressive ECM dysregulation at the tumor periphery can link the formation of invasive tumor niches to the aggressive, resistant, and mesenchymal-like phenotypes present in GBM recurrent tumors.

Keywords:  Brain Tumor; Epigenetics; Extracellular Matrix; Glioblastoma; Mechanical Memory; Stiffness

DOI:  https://doi.org/10.1093/neuonc/noaf205
bioRxiv. 2025 Sep 11. pii: 2025.09.06.674490. [Epub ahead of print]

Dual checkpoint blockade of glioblastoma with Anti-PD-1 and Anti-LAG-3 promotes expansion of tumor-reactive T cell clones along a unique pathway of differentiation.

Mingshuang Wang, Yuntian Fu, Sadhana Bom, Yi Ning, Divij Matthews, Ming Zhang, Calixto-Hope Lucas, John Choi, Zhen Zeng, Tianbei Zhang, Hongkai Ji, Vasan Yegnasubramanian, Jon Weingart, Chetan Bettegowda, Kellie N Smith, Michael Lim, Drew Pardoll, Nancy R Zhang, Christina Jackson.

IDH-wildtype grade IV glioblastoma is the most aggressive adult primary brain tumor and remains refractory to anti-PD-1 monotherapy despite evidence of limited tumor-specific T cell induction. To determine the impact of immune checkpoint inhibitors (ICIs) on glioblastoma T cell transcriptional landscape and repertoire, we conducted paired single-cell RNA sequencing (scRNA-seq) and T cell receptor sequencing (TCR-seq) of tumor-infiltrating lymphocytes (TILs) from patients with untreated, newly diagnosed glioblastoma and from recurrent glioblastoma treated with dual checkpoint blockade targeting PD-1 and LAG-3. Using a validated transcriptional signature, we found that predicted tumor-reactive T cells (TRC) in untreated glioblastomas reside almost exclusively in a clonally expanded GZMK hi population with developmental plasticity, affording them the potential to differentiate into both tissue-resident and terminal effector T cells. Dual ICI therapy induced substantial clonal remodeling, characterized by the recruitment of new TRC from the periphery into the tumor microenvironment (TME) and differentiation into transitional effectors and ultimately terminal effectors along a gradient characterized by simultaneous acquisition of cytotoxic and exhaustion genes, regulated by specific transcriptional, metabolic, and epigenetic programs. Longitudinal clonal tracking in peripheral blood confirmed that with ICI treatment, most TRC expand transiently in circulation prior to tumor infiltration, with peripherally derived clones becoming the major contributor to the GZMK hi TRC that further expand in the tumor. Our study provides the first comprehensive map of T cell clonal dynamics and differentiation in glioblastoma following dual ICIs and highlights a potential mechanism of immune activation and peripheral recruitment of TRC in glioblastoma not previously described. Our results suggest that therapeutic strategies to sustain these GZMK hi early effector and transitional effector T cells may further enhance ICI therapeutic efficacy in glioblastoma.

DOI: https://doi.org/10.1101/2025.09.06.674490
Neuro Oncol. 2025 Sep 18. pii: noaf224. [Epub ahead of print]

Multiple patient-derived glioblastoma models reveal synthetic lethality through concurrent PI3K and CDK4/6 inhibition by blocking trans-active cooperation.

Jing Zhang, Xu Chen, Meng Cheng, Jingzhe Wang, Yueyao Wu, Han Xie, Chunyu Zhang, Honghao Wang, Ying Pang, Tongjie Ji, Yuntong Yang, Junyu Yang, Siyi Xu, Zhigang Wang, Qi Wang, Min Liu, Chunlong Zhong.

   BACKGROUND: Dysregulation of the PI3K signaling pathway has been recognized as a pivotal oncogenic driver in GBM progression. Although PI3K inhibitors have demonstrated initial therapeutic efficacy, the development of resistance through compensatory upregulation of alternative signaling pathways substantially limits their clinical benefits. However, the molecular mechanisms underlying this resistance to PI3K monotherapy in GBM remain incompletely understood.
METHODS: Multiple patient-derived glioblastoma models including organoids (GBOs), primary dissociated cells (PDCs) and xenografts (PDCX) were established as clinically relevant platforms to evaluate the feasibility of tailored therapy. Comprehensive molecular profiling and functional analyses were conducted across these patient-derived models. RNA sequencing, mass spectrometry, DNA spreading assays, HR /NHEJ reporter assays and mIF were performed to elucidate the molecular underpinnings of PI3K and CDK4/6 co-activation in driving tumor evolution, and to reveal the synthetic lethality efficacy of the concurrent strategy.
RESULTS: Our findings demonstrate that PI3K monoinhibition induces aberrant CDK4/6 activation, and co-activation of PI3K-CDK4/6 signaling positively correlates with monotherapy resistance, which is driven by tumor evolution. The concurrent strategies with PI3K and CDK4/6 inhibition synergistically achieve therapeutic efficacy in suppressing the growth of GBOs, PDCs and PDCX. Mechanistically, insufficient DNA damage response under PI3Ki mono-therapy upregulated CDK4/6, driving aberrant cell cycle progression. The small-molecule inhibitors paxalisib and ribociclib potently suppress tumor proliferation, which induced persistent replication stress and genomic instability.
CONCLUSIONS: Employing multiple patient-derived models, our study uncovers clinically relevant PI3Ki resistance mechanisms and advocates a rationale for synthetic lethality through combined PI3K-CDK4/6 inhibition, offering substantial therapeutic potential for GBM patients.

Keywords:  DNA damage repair; Glioblastoma; drug resistance; patient-derived 3D models; synthetic lethality

DOI:  https://doi.org/10.1093/neuonc/noaf224
bioRxiv. 2025 Sep 04. pii: 2025.08.30.673205. [Epub ahead of print]

Understanding and imaging PHGDH-driven intrinsic resistance to mutant IDH inhibition in gliomas.

Céline Taglang, Georgios Batsios, Anne Marie Gillespie, Joanna J Phillips, Jennie W Taylor, Pavithra Viswanath.

Mutations in isocitrate dehydrogenase (IDHm) define a distinct molecular class of gliomas. IDHm converts α-ketoglutarate (α-KG) to the oncometabolite D-2-hydroxyglutarate (D-2HG), which drives tumorigenesis. The IDHm inhibitor vorasidenib suppresses D-2HG production and extends progression-free survival in some, but not all, IDHm glioma patients. Here, using clinically relevant patient-derived IDHm models and patient tissue, we show that phosphoglycerate dehydrogenase (PHGDH) drives intrinsic resistance to vorasidenib by promiscuously converting α-KG to D-2HG and maintaining D-2HG concentration despite IDHm inhibition. Silencing PHGDH sensitizes resistant models to vorasidenib, while conversely, overexpressing PHGDH induces vorasidenib resistance in sensitive models. Importantly, deuterium metabolic imaging of D-2HG production from diethyl-[3,3'- 2 H]-α-ketoglutarate provides an early readout of response and resistance to vorasidenib that is not available by anatomical imaging in vivo. Collectively, we have identified PHGDH-driven D-2HG production as an intrinsic mechanism of resistance to vorasidenib and diethyl-[3,3'- 2 H]α-ketoglutarate as a non-invasive tracer for interrogating intrinsic resistance in IDHm gliomas.
STATEMENT OF SIGNIFICANCE: Vorasidenib, which suppresses D-2HG production, is the first precision therapy to be approved for IDHm glioma patients. We show that PHGDH-driven restoration of D-2HG production mediates intrinsic resistance to vorasidenib in IDHm gliomas. Importantly, deuterium metabolic imaging of D-2HG production from diethyl-[3,3'- 2 H]-α-ketoglutarate enables non-invasive assessment of resistance in IDHm gliomas.

DOI: https://doi.org/10.1101/2025.08.30.673205
Neuro Oncol. 2025 Sep 20. pii: noaf206. [Epub ahead of print]

Single-cell profiling of peripheral and local immune compartments reveal unique genotype-independent prognostic immune signatures across IDH-stratified glioma.

Jonathan H Sussman, Anthony R Cillo, Sajeev Kohli, Carly Cardello, Jonathan Patterson, Ebrar Akca, Angelo Angione, David Moon, Katharine Krueger, Ali Ghamari, Emily Xu, Jessica Xu, Antonio C Tarbay, Alex Li, Bhargavi R Budihal, Xiaoran Zhang, Omar Elghawy, Wojciech K Panek, Prajwal Rajappa, Kai Tan, Dario A A Vignali, Tullia C Bruno, Nduka M Amankulor.

   BACKGROUND: Solid tumor immune suppression requires cooperation of tumor cells, local immune cells, peripheral circulating immune cells, and evolution of immune cell trajectories between peripheral and local environments. This study addresses a significant knowledge gap by characterizing peripheral and local immune environments in IDH Mutant (IDH-Mut) and IDH wildtype (IDH-WT) gliomas and defines novel immunological states with prognostic relevance across the glioma landscape.
METHODS: We analyzed local and peripheral immune phenotypes in a cohort of 18 (6 IDH-Mut and 12 IDH-WT) gliomas with distinct genetic characteristics using paired human tumor and peripheral blood mononuclear cells (PBMCs) with single-cell RNA-sequencing (scRNA-seq).
RESULTS: Our analyses revealed unique intratumoral and peripheral immune cellular ontogenies, including naïve CD4+ T cell enrichment in the IDH-Mut peripheral immune compartment, monocyte enrichment in IDH-WT glioma PBMCs, and emergence of a unique population of GZMH+ CD8+ T cells preferentially in the IDH-Mut microenvironment. Additionally, we found upregulation of TNF-α signaling and inflammatory response pathways in IDH-Mut-glioma-associated peripheral lymphoid cells versus IDH-WT tumors and identified a novel population of microglia-like cells in the peripheral blood of glioma patients with complement-interfacing characteristics. Applying intratumoral transcriptomic deconvolution via The Cancer Genome Atlas revealed genotype-independent, prognostic immune signatures across the malignant glioma landscape.
CONCLUSIONS: This study reveals variable expression of immune phenotypes in adult gliomas stratified by IDH status and characterizes immune compartment and genotype-dependent differences in the immunologic glioma landscape. These genotype-dependent, tumor and circulating immune ontogenies should guide future diagnostic and immunotherapeutic considerations in malignant glioma.

Keywords:  IDH Mutant glioma; circulating immune cells; immunotherapy; single-cell sequencing; tumor immune microenvironment

DOI:  https://doi.org/10.1093/neuonc/noaf206
Cancer Cell. 2025 Sep 18. pii: S1535-6108(25)00366-6. [Epub ahead of print]

Restraint of cancer cell plasticity by spatial homotypic clustering.

Simona Migliozzi, Bruno Adabbo, Luciano Garofano, Fan Wu, Pedro Davila, Ricardo J Komotar, Michael E Ivan, Ashish H Shah, Benjamin B Currall, Sion Williams, Daniel Bilbao Cortes, Melinda Minucci Boone, Macarena I de la Fuente, Sakir H Gultekin, Michele Ceccarelli, Antonio Iavarone, Anna Lasorella.

  Tumor heterogeneity fueled by plasticity of cancer cells is a key to therapy failure. Here, we define the role of proximal communications of malignant cells in glioblastoma plasticity. We find that tumor cell state coherence is maximal in cells organized in homotypic clusters with defined relationships with non-malignant cells, whereas randomly dispersed cells downregulate the original state, acquire alternative phenotypes and exhibit changes in the microenvironment. We demonstrate the intrinsic propensity of glioblastoma cells to develop into clustered and dispersed spatial patterns in orthotopic mouse models and experimentally validate the cell state-specific mechanisms of cell-cell adhesion that prevent phenotype deviation with pharmacologic perturbations in patients-derived glioblastoma models. We establish the generality of "homotypic clustered cell identity" in circulating clustered and single breast cancer cells and show that the glioblastoma glycolytic-plurimetabolic dispersed cellular state uniquely confers shorter survival, thus assigning clinical significance to the spatial patterning of cancer cells in human tumors.

Keywords:  cancer cell plasticity; glioblastoma; intratumor heterogeneity; single-cell spatial proteomics; single-cell spatial transciptomic; tumor ecosystem

DOI:  https://doi.org/10.1016/j.ccell.2025.08.009
Neuro Oncol. 2025 Sep 17. pii: noaf216. [Epub ahead of print]

Transcriptomics-Guided High-Throughput Drug Screening Identifies Potent Therapies for P53 Pathway Alterated DIPG/DMG.

Zhuang Jiang, Luyang Xie, Hang Zhou, Yibo Geng, Xiong Xiao, Tian Li, Yuxuan Deng, Mingxin Zhang, Shaobo Shan, Cheng Xu, Liwei Zhang.

   BACKGROUND: Diffuse midline gliomas (DMGs), particularly diffuse intrinsic pontine gliomas (DIPGs), are aggressive pediatric brain tumors with a median survival of less than 12 months. Notably, approximately 70% of these tumors harbor P53 pathway alterations, including TP53 or PPM1D mutations. Identifying precision therapies for this subset is crucial. This study aims to employ transcriptomics-guided high-throughput drug screening to identify effective treatments for DIPG/DMG with P53 pathway alterations.
METHODS: Transcriptomic profiling of 98 patient samples containing 31 DIPGs revealed key activated pathways. Patient-derived cell lines were subjected to high-throughput screening using a cell cycle-targeting drug library. Lead candidates were validated both in vitro and in orthotopic xenograft models, while combination therapies were assessed for their ability to overcome TP53-mutant resistance.
RESULTS: Transcriptomic analysis revealed activation of P53 and cell cycle pathways in DIPGs. High-throughput drug screening identified SN-38, a topoisomerase I inhibitor, as selectively targeting TP53 wild-type tumor cells by inducing G2 arrest and apoptosis. TP53 knockdown abolished SN-38's efficacy, while PPM1D knockdown enhanced sensitivity, confirming a TP53-dependent mechanism. Conversely, TP53-mutated cells exhibited SN-38 resistance via ATR pathway activation. Combining SN-38 with the ATR inhibitor AZ20 restored apoptosis and suppressed TP53-mutant tumor growth in vitro and in vivo.
CONCLUSIONS: Guided by transcriptomic profiling, this study utilized high-throughput drug screening to identify SN-38 as a potential therapy for TP53 wild-type DIPG/DMG, while the SN-38 and AZ20 combination was effective against TP53-mutant tumors. This approach provides a promising treatment strategy for this malignancy and establishes a novel paradigm for drug screening in DIPG/DMG.

Keywords:   TP53 ; AZ20; DIPG/DMG; Drug Screening; SN-38

DOI:  https://doi.org/10.1093/neuonc/noaf216
Proc Natl Acad Sci U S A. 2025 Sep 23. 122(38): e2414941122

Wnt inhibition alleviates resistance to anti-PD1 therapy and improves antitumor immunity in glioblastoma.

Shanmugarajan Krishnan, Somin Lee, Zohreh Amoozgar, Sonu Subudhi, Ashwin Srinivasan Kumar, Jessica M Posada, Neal Lindeman, Pinji Lei, Mark Duquette, Sophie Steinbuch, Marc Charabati, Peigen Huang, Patrik Andersson, Meenal Datta, Lance L Munn, Dai Fukumura, Rakesh K Jain.

  Wnt signaling plays a crucial role for many developmental processes. It is also pivotal in the generation and limited treatment outcomes of glioblastoma (GBM). Here, we identified Wnt7b, which is markedly upregulated in GBM patients, as a determinant of resistance to immune checkpoint blockers (αPD1; anti-Programmed Cell Death Protein 1) in a clinically relevant, αPD1-resistant GBM murine model with abundant stem cells. We observed that increased levels of Wnt7b and β-catenin correlated with the resistance to αPD1. Treatment combining a porcupine inhibitor WNT974 with αPD1 reprogrammed the immune suppressive tumor microenvironment (TME) to bolster antitumor immune responses and extended the survival of mice bearing orthotopic GBM, with 25% long-term survivors. Our causal studies revealed that WNT974 potentiated αPD1 therapy by the expansion of antigen presenting DC3-like dendritic cells (DCs). Additionally, WNT974 combination with αPD1 was associated with a reduction in immune suppressive granulocytic myeloid-derived suppressor cells (MDSCs), an increase in the Ki67+CD8/Ki67+regulatory T cells (Treg) ratio, tilting the CD8:Treg balance in the TME toward antitumor immune response, and more pronounced GrzB+CD8+ effector T cells. Conversely, an increase in monocytic MDSCs and phosphorylation of pro-oncogenic proteins was associated with resistance to the combination therapy. Collectively, our preclinical findings provide a strong rationale to test Wnt7b/β-catenin inhibition with αPD1 therapy in GBM patients with elevated Wnt7b/β-catenin signaling.

Keywords:  Wnt7b/β-catenin; dendritic cells; glioblastoma; immunotherapy; stem cells

DOI:  https://doi.org/10.1073/pnas.2414941122
Neuro Oncol. 2025 Sep 15. pii: noaf215. [Epub ahead of print]

EGFR/ZBED1 reciprocal regulation promotes stemness and tumorigenesis in glioblastoma.

Nana Hou, Yutao Wang, Qiuxiang You, Lei Zhang, Wenjia Zhang, Xinyi Wang, Chunyan Deng, Jiachuan Yan, Saiyu Cheng, Jianwen Ji, Jianbing Hou, Hongjuan Cui, Yundong Zhang.

   BACKGROUND: Glioblastoma stem cells (GSCs), a stem-like tumorigenic subpopulation within glioblastoma (GBM), exhibit remarkable self-renewal capacity and therapeutic resistance. Zinc finger BED domain-containing protein 1 (ZBED1), a dual-function transcription factor and SUMO E3 ligase, has been implicated in oncogenic processes across malignancies, its functional role and regulatory mechanisms in GSCs remain enigmatic.
METHODS: Multimodal approaches including immunohistochemistry, immunoblotting, and immunofluorescence were employed to evaluate ZBED1 expression patterns in GSCs and clinical GBM specimens. Functional characterization utilized in vitro models (proliferation assays, tumor-sphere formation assays, limiting dilution analysis) complemented by in vivo orthotopic xenograft models. Mechanistic investigations integrated RNA sequencing, label-free proteomics, chromatin immunoprecipitation (ChIP), immunohistochemistry, and western blotting to delineate the EGFR/ZBED1 regulatory axis.
RESULTS: We demonstrated that ZBED1 was significantly upregulated in GSCs and linked to unfavorable prognosis. Genetic ablation of ZBED1 significantly impaired GSC proliferation and self-renewal capacity, while extending survival in xenograft models. Mechanistically, EGFR-mediated ZBED1 phosphorylation at tyrosine residues Y160/Y513 enhanced ZBED1-UBC9 interaction, promoting SUMOylation-dependent protein stabilization. Remarkably, ZBED1 reciprocally sustained EGFR expression through transcriptional repression of the E3 ubiquitin ligase PARK2, establishing a self-reinforcing EGFR/ZBED1/PARK2 signaling circuit critical for GSC maintenance.
CONCLUSIONS: Our findings elucidate a novel EGFR/ZBED1 positive feedback loop that drives GSC propagation and tumorigenesis, highlighting ZBED1 as an attractive candidate for therapeutic targeting in GBM.

Keywords:  EGFR; SUMOylation; ZBED1; glioblastoma; phosphorylation

DOI:  https://doi.org/10.1093/neuonc/noaf215
Acta Neuropathol. 2025 Sep 17. 150(1): 29

Spatial transcriptomic analysis reveals lack of response to PD-1 blockade in recurrent glioblastoma.

Sara Blaabjerg Artzi, Marc Nihøj Klausen, Dylan Scott Lykke Harwood, Signe Regner Michaelsen, Simone Bendix Maarup, Alessio Locallo, Vincent Fougner, Nicolai Schou Bager, Nadine Margaretha Hammouda, Dorte Schou Nørøxe, Benedikte Hasselbalch, Ulrik Lassen, Joachim Weischenfeldt, Bjarne Winther Kristensen.

  Immune checkpoint inhibitors have transformed treatment for several cancers, yet clinical trials of programmed cell death protein 1 (PD-1) blockade in glioblastoma (GBM) have consistently failed to show therapeutic benefit. While some studies have reported treatment-related transcriptional changes, particularly in T cells, findings remain limited and inconsistent. The aim of this study was to investigate changes in tumor cells and tumor-associated macrophages (TAMs) after PD-1 blockade in recurrent GBM using spatial transcriptomics. We performed Digital Spatial Profiling (GeoMx, NanoString) on FFPE tumor samples from 26 patients with matched primary and recurrent IDH-wildtype GBM, including 16 patients who received neoadjuvant nivolumab at recurrence. Tumor (SOX2⁺) and TAM (IBA1⁺) segments were selected for targeted spatial analysis. Following quality control and filtering, transcriptomic profiles were compared between nivolumab-treated and untreated recurrent tumors. PD-1 blockade did not induce detectable gene expression changes in either tumor cells or TAMs. There were no significant differences in global expression profiles or in more targeted analyses of malignant cell states, cell cycle activity, interferon signaling, or myeloid transcriptional programs. These results consistently indicate that neoadjuvant PD-1 blockade does not elicit measurable responses at the spatial transcriptomic level in tumor cells or TAMs in recurrent GBM. These findings align with the lack of clinical benefit observed in trials and highlight the need for alternative strategies to improve immunotherapy outcomes in GBM.

Keywords:  Glioblastoma; Immunotherapy; Recurrence; Spatial transcriptomics; Tumor microenvironment

DOI:  https://doi.org/10.1007/s00401-025-02937-9
Cancer Res. 2025 Sep 18.

Quantitative Cell Type Specific Immunopeptidome Analysis of Macrophage and Tumor Co-evolution Reveals Therapeutic MHC-I Peptides in Glioblastoma.

Yufei Cui, Kien Phuong, Nouran S Abdelfattah, Heidi M Temple, Laura Maiorino, B J Kim, Jonathan Dye, Kenny Kwok Hei Yu, Stefani Spranger, Forest M White.

Immune checkpoint inhibitors (ICI) have shown impressive performance in treating several types of solid tumors. However, they have been ineffective in glioblastoma (GBM), in part due to the immunosuppressive tumor microenvironment (TME) created by GBM-associated macrophages (GAMs). To uncover MHC-I peptide antigens for targeted immunotherapy, we performed cell type specific immunopeptidome analysis on primary macrophages and GBM tumor cells in a co-culture system to profile MHC-I associated antigen presentation at the tumor-macrophage interface. Co-culturing tumor cells and macrophages induced increased presentation of peptides derived from proteins associated with cytokine signaling pathways on macrophages and from proteins associated with the Rho GTPase pathway on GBM tumor cells. In vivo expression was validated for a cohort of co-culture-induced GAM or GBM associated peptides selected as potential immunotherapy targets, and an mRNA vaccine was developed encoding six peptides from GAMs and GBM tumor cells. Two doses of vaccination generated an antigen specific immune response, significantly delayed GBM tumor growth, and in some cases eradicated tumors. These results demonstrate the translational potential of co-culture induced MHC peptide antigens as therapeutic targets for GBM/GAM targeting vaccines.

DOI: https://doi.org/10.1158/0008-5472.CAN-24-4674
bioRxiv. 2025 Sep 04. pii: 2025.09.01.673023. [Epub ahead of print]

Preclinical efficacy of combinatorial B7-H3 CAR T cells and ONC206 against diffuse intrinsic pontine glioma.

Andrea Timpanaro, Edward Z Song, Ryma Toumi, Leonel Elena-Sanchez, Michael Meechan, Caroline Piccand, Kelsey Nemec, Anja Kordowski, Davina Lau, Scott Johnson, Lily Winter, Ashmitha Rajendran, Rebecca Ronsley, Shannon K Oda, Joshua Gustafson, Jason P Wendler, Carl Koschmann, Myron Evans, Siobhan Pattwell, Michael C Jensen, Jessica B Foster, Matthew D Dun, Matthew C Biery, Nicholas A Vitanza.

Background: Diffuse intrinsic pontine glioma (DIPG) is a fatal pediatric brain tumor affecting over 300 children annually in the United States. Chimeric antigen receptor (CAR) T cells are a targeted immune effector cell therapy with substantial clinical benefit against hematologic cancers. Against CNS tumors, CAR T cells targeting B7-H3, a protein highly expressed on DIPG, have rapidly advanced from preclinical studies to clinical trials. BrainChild-03 ( NCT04185038 ), a phase 1 trial of repeatedly delivered intracerebroventricular (ICV) B7-H3-targeting CAR T cells (B7-H3 CAR T cells), demonstrated tolerability and potential efficacy for children and young adults with DIPG. However, clinical benefits were not uniformly seen, and multi-agent treatment strategies may be required against such an aggressive disease. Here, we combined B7-H3 CAR T cells with ONC206, an imipridone molecule also under clinical investigation.
Methods: We tested B7-H3 CAR T cells combined with ONC206 across multiple DIPG cell cultures and orthotopic xenograft mouse models.
Results: B7-H3 CAR T cell monotherapy induced robust cytotoxicity while ONC206 treatment resulted in significant mitochondrial dysfunction against DMG/DIPG cells. The combination of low effector-to-target ratios of B7-H3 CAR T cells and IC 50 concentrations of ONC206 led to significantly enhanced cytotoxicity in vitro (p<0.003) and increased IL-2, IL-29, VEGF-A, and Granzyme B levels. In vivo combinatorial studies of ONC206 and a single ICV dose of B7-H3 CAR T cells significantly extended survival in multiple DIPG xenograft mouse models (p<0.05).
Conclusions: B7-H3 CAR T cells combined with ONC206 is a feasible and efficacious multi-agent approach against multiple DIPG models.
Importance of the study: Diffuse intrinsic pontine glioma (DIPG) is a fatal pediatric brain tumor. While B7-H3 CAR T cells have shown tolerability and potential benefit in early trials, combinatorial regimens may be required for consistent cures against this aggressive disease. This study demonstrates that a preclinical therapeutic regimen of B7-H3 CAR T cells with ONC206, a second-generation imipridone, increases anti-tumor efficacy in vitro and in orthotopic DIPG mouse models. To our knowledge, this is the first study to evaluate ONC206 in combination with CAR T cells. Our findings provide a preclinical roadmap for evaluating small molecules with CAR T cells to interrogate both their combined benefit and the effect of small molecules on T cells themselves. This work offers a biologically-informed, clinically translatable strategy integrating small molecule therapeutics with CAR T cell therapy and support the development of multi-agent immunotherapy trials for children with DIPG and other high-grade brain and spinal cord tumors.
Key Points: B7-H3 CAR T cells are cytotoxic against preclinical DMG models.ONC206 causes metabolic apoptosis in preclinical DMG models.B7-H3 CAR T cells and ONC206 have combinatorial efficacy against DMG.

DOI: https://doi.org/10.1101/2025.09.01.673023
Cell Rep. 2025 Sep 13. pii: S2211-1247(25)01074-5. [Epub ahead of print]44(9): 116303

Connexin 43 drives glioblastoma cancer stem cell phenotypes through a WNK lysine-deficient protein kinase 1-c-MYC signaling axis.

Erin E Mulkearns-Hubert, Nicole Hajdari, Ellen S Hong, Ashley P Jacobs, Aymerick Gaboriau, Sophia Giltner, Gavin Tannish, Kristen E Kay, Sabrina Z Wang, Peter S LaViolette, Daniel J Silver, Christopher G Hubert, Andrew Dhawan, Justin D Lathia.

  The coordination of cellular processes such as growth and survival relies on communication between cells through gap junctions. Connexin proteins comprise gap junctions and also function to mediate protein-protein interactions and communication with the extracellular space via hemichannels. Despite their essential roles, connexin function in cancer is context dependent, with connexin 43 (Cx43) reported to both promote and suppress tumor growth in glioblastoma, the most common primary malignant brain tumor. Here, we detect primarily intracellular expression of Cx43 in glioblastoma patient-derived cancer stem cells and demonstrate that Cx43 is essential for their survival, self-renewal, and tumor initiation. Mechanistically, Cx43 depletion reduces c-MYC expression through reduced levels of the upstream mediator WNK lysine-deficient protein kinase 1 (WNK1). WNK1 depletion phenocopies Cx43 knockdown and reduces c-MYC expression and tumor initiation. Together, these results define a signaling axis downstream of Cx43 that promotes tumor growth and cancer stem cell phenotypes in glioblastoma.

Keywords:  CP: Cancer; WNK1; c-MYC; cancer; cancer stem cell; connexin; glioblastoma; signaling

DOI:  https://doi.org/10.1016/j.celrep.2025.116303
Nat Immunol. 2025 Sep 15.

A spatial map of MAPK-activated immunosuppressive myeloid populations in pediatric low-grade glioma.

Augusto Faria Andrade, Romain Sigaud, Evan Puligandla, Bridget Liu, Elham Karimi, Alva Annett, Morteza Rezanejad, Wajih Jawhar, Robert Taylor, Yi Cao, Simone Schmid, Florian Selt, Pablo Hernáiz Driever, Svea Horn, Philipp Sievers, Marco Prinz, Markus Glatzel, Christian Mawrin, Christian Hartmann, Camelia-Maria Monoranu, Liza Konnikova, Felix Sahm, Stefan M Pfister, Olaf Witt, David T W Jones, Arend Koch, Claudia L Kleinman, David Capper, Logan Walsh, Nada Jabado, Till Milde.

Pediatric low-grade gliomas (pLGGs) are mitogen-activated protein kinase (MAPK) pathway-activated brain tumors prevalent in children and are associated with morbidity despite favorable survival. Here using imaging mass cytometry, we spatially characterized at the single-cell level the tumor microenvironment (TME) of 120 pLGG cases, considering age, molecular drivers, brain location and tumor subtype. Our analysis identified myeloid cells-including resident microglia and bone marrow-derived macrophages-as the predominant immune population in the TME, particularly in optic pathway tumors. Additionally, we discovered an immune signature predictive of progression-free survival. Spatial analysis identified specific cellular interactions, notably myeloid-myeloid contacts and macrophage-enriched regions harboring MAPK-activated, TIM-3+ myeloid cells, suggesting an immunosuppressive TME. Our study provides a comprehensive resource on the immune landscape of these pLGGs and underscores the immunosuppressive role of diverse myeloid infiltrates. These findings also indicate that combining TIM-3 blockade with MAPK inhibition might be a promising therapeutic strategy to target both the TME and oncogenic MAPK activation in pLGG tumors.

DOI: https://doi.org/10.1038/s41590-025-02268-7