Neuro-oncology最新文献

Background: Approximately 10% of cancers achieve replicative immortality through a telomerase-independent mechanism of telomere maintenance, termed Alternative Lengthening of Telomeres (ALT). ALT is particularly prevalent in certain subtypes of malignant gliomas, such as IDH-mutant astrocytoma and pediatric glioblastoma, and frequently co-occurs with ATRX inactivating mutations. Although ALT is an adaptive mechanism through which cancer cells achieve proliferative immortality, the elevated levels of replication stress observed in ALT tumors constitute a potential therapeutic vulnerability.

Methods: Leveraging CRISPR/Cas9 screening data from the Cancer Dependency Mapping Project, coupled with patient-derived cell lines and xenografts, we identified SMARCAL1 as a novel synthetic lethal vulnerability in ATRX-deficient glioma models that engage ALT. Using complementary molecular assays for DNA damage, telomere maintenance, and telomeric replication stress, we define the mechanisms underlying cytotoxicity induced by SMARCAL1 depletion in ALT-positive glioma cells.

Results: Our data demonstrate the annealing helicase SMARCAL1 is a highly specific synthetical lethal vulnerability in cancers that use ALT. SMARCAL1 localizes to ALT-associated PML bodies in ALT-positive glioma cell lines, including IDH-mutant astrocytomas. SMARCAL1 depletion, via doxycycline-induced RNAi, led to a hyperactivation of the ALT phenotype, high levels of DNA double-strand breaks in G2 phase, and cell death via mitotic catastrophe. In mice bearing intracranial xenografts derived from high-grade IDH-mutant astrocytoma, inducible SMARCAL1 depletion prolonged animal survival.

Conclusions: Our findings demonstrate that the molecular processes orchestrating ALT-mediated telomere maintenance constitute a targetable synthetic lethal vulnerability that can be exploited by SMARCAL1 inhibition, thus supporting the future development of small molecule inhibitors of SMARCAL1 as anti-cancer therapeutics.

Glioblastoma is characterized by heterogeneous and plastic cellular populations that adopt transcriptional programs shaped by genetic alterations and microenvironmental cues. Recent studies have identified at least four partially inconvertible cell states-astrocytic-like, neural progenitor-like, oligodendrocyte progenitor-like, and mesenchymal-like-that represent aberrant developmental programs. Expanded analysis further reveals hybrid and intermediate states that form continuous transcriptional and metabolic gradients. These states exhibit spatial organization, assembling into three distinct microanatomical niches: a perivascular niche enriched with mesenchymal-like and oligodendrocyte progenitor-like cells, a hypoxic niche harboring quiescent and stressed cells of all states, and an invasive niche containing astrocyte-like or proneural populations. Niches continuously remodel as cell states transition, migrate, and re-establish new programming in response to angiogenesis, hypoxia, immune infiltration, and neuronal activity. This interplay between states and the microenvironment generates a self-renewing spatial architecture, maintaining expansion at the edge and protection within the core. This review integrates single-cell, single-nucleus, and spatial studies to describe a microenvironmental-driven model of cell state organization. Understanding how these multiscale drives converge to generate a continuum of cell state identities may reveal strategies to disrupt the spatial architecture underlying glioblastoma plasticity and recurrence.

Background: Trastuzumab deruxtecan (T-DXd) is an antibody-drug conjugate (ADC) approved for metastatic HER2+ and HER2-low/ultralow breast cancer. It has shown impressive clinical activity for HER2+ brain metastases. We conducted preclinical brain metastasis experiments to understand T-DXd efficacy.

Methods: Nude mice were intracardiacly injected with either JIMT1-BR (HER2-2+) or SUM190-BR (HER2-3+) brain-tropic breast cancer cells and dosed with 3 or 10 mg/kg T-DXd or 10 mg/kg control-ADC, with endpoints of metastasis number and size, in both the metastasis prevention and treatment of established disease settings.

Results: In the JIMT1-BR model, T-DXd at both doses reduced metastasis number by 48-88% and size by 32-88%; a reduction of HER2 expression by lesions remaining at the experimental endpoint and heterogeneous T-DXd distribution were observed. A distinct dose effect was observed in SUM190-BR with the 3 mg/kg dose inhibiting size and number by 24-39% and 10 mg/kg by 72-79%; HER2 expression was maintained together with heterogeneous T-DXd distribution. In both models widespread reduced tumor Ki-67 was observed, while increased cleaved caspase-3 primarily costained with T-DXd. We used an in vitro model of the blood-brain- and blood-tumor barriers (BBB/BTB) to ask how T-DXd crossed. Data demonstrated T-DXd endocytosis and transcytosis of brain endothelial cells partially reliant on the neonatal Fc receptor (FcRn). BTB transcytosis was accompanied by increased endothelial RAB11FIP5 expression in vitro and in vivo.

Conclusions: The data confirm T-DXd activity in HER2+ brain metastases and identify important correlates including heterogeneous uptake, variable HER2 expression at endpoint, tumor cell cytotoxicity, decreased proliferation, and BTB transcytosis.

Background: Cellular heterogeneity is a defining feature of glioblastoma (GBM), shaping tumor progression and therapeutic response. While single-cell profiling resolves this heterogeneity, it remains impractical for large-cohort studies and clinical implementation. Conversely, DNA methylation-based classification is widely used for GBM diagnostics but does not provide cellular resolution.

Methods: We introduce a hierarchical non-negative matrix factorization approach (ITHresolveGBM) to deconvolute bulk DNA methylation profiles, inferring the abundance of glial, immune, and neuronal cells of the microenvironment, and further distinguishing differentiation states of malignant cells.

Results: Using ITHresolveGBM, we find that low tumor cell content impairs methylation-based classification, most notably linking the mesenchymal subtype with high immune cell infiltration. By integrating multi-omic single-cell data, we show that epigenetic deconvolution captures a malignant differentiation continuum ranging from stem-like to more differentiated tumors. This continuum aligns prior GBM classification systems and is associated with distinct molecular drivers (e.g., PDGFRA, TP53, EGFR) and survival outcomes.

Conclusions: Our framework reconciles DNA methylation- and RNA-based classification systems and provides a blueprint for unifying bulk tumor profiles with single-cell biology, thereby refining molecular stratification and enhancing GBM diagnostics.

Background: Neuroblastoma (NB) is the most common extracranial solid tumor in children and accounts for 15% of childhood cancer death. The nucleosome remodeling and deacetylase (NuRD) complex is a major chromatin remodeling complex that regulates chromatin accessibility and gene transcription. However, its role in the pathogenesis of neuroblastoma remains poorly understood.

Methods: The genetic dependency and clinical significance of MBD3 in neuroblastoma was evaluated by analysis of public datasets. The function of MBD3 in neuroblastoma cell growth was evaluated by shRNA knockdown experiment. Cleavage under targets and tagmentation sequencing (CUT&Tag-seq), coupled with RNA-sequencing, was employed to explore the mechanisms involved in the epigenetic regulation executed by NuRD decommissioning following MBD3 deficiency.

Results: Here we find that MBD3 is the most lineage-selective dependency among the non-enzymatic subunits of the NuRD complex in neuroblastoma. Knockdown of MBD3 induces cell cycle arrest and apoptosis, and inhibits neuroblastoma growth in vivo. Mechanistically, MBD3 deficiency leads to decommissioning of the NuRD complex and dissociation of the EZH2-PRC2 complex from chromatin, thereby orchestrating the epigenetic regulation of gene expression by modulating the balance between histone acetylation and methylation. NuRD decommissioning upon MBD3 deficiency selectively downregulates the expression of core regulatory transcription factors and upregulates a tumor suppressor SRCIN1, collectively suppressing neuroblastoma progression.

Conclusions: Our data identify MBD3 and the NuRD complex as potential therapeutic targets in neuroblastoma, highlighting the critical role of epigenetic regulation in tumor maintenance. Targeting this pathway may offer a novel strategy to selectively impair neuroblastoma cell survival and improve outcomes.

Background: Although the genetic evolution of IDHwt glioblastomas has extensively been investigated, limited studies have addressed the epigenetic evolution. Understanding the epigenetic evolution is particularly relevant as demethylation of the MGMT promoter may form a means of treatment resistance.

Methods: We generated whole genome DNA methylation data of 64 matched primary-recurrent samples from IDHwt glioblastoma patients. Data were combined with three publicly available datasets into a cohort consisting of 418 samples. MGMT promoter methylation was determined using the MGMT-STP27 algorithm. CoxPH regression was used to investigate the impact of identified changes on survival.

Results: Our analysis demonstrate that the methylome of IDHwt glioblastomas was highly stable (93%). Changes that occur could mostly be allocated to differences in tumor purity. Conversion from a methylated MGMT promoter to unmethylated status at progression occurred infrequently (9/66, 13.6%), but significantly more often than the converse (4/113, 3.5%). Conversion was associated with worse overall- and progression-free survival compared to patients whose tumors remained MGMT methylated. Despite a large survival difference between patients with MGMT promoter-methylated and unmethylated tumors, very few CpGs were differentially methylated between samples from MGMT methylated and unmethylated tumors. Of the ones that were, the vast majority were located within the MGMT gene body and were inversely correlated with MGMT promoter methylation status.

Conclusion: The methylome of IDHwt glioblastomas is highly stable at tumor progression. In this series, only 7% of tumors showed change in MGMT promoter methylation status at progression.

Background: Glioblastoma (GBM) is a highly aggressive brain tumor with profound metabolic heterogeneity. However, a clinically actionable classification based on metabolic gene expression remains undefined.

Methods: We conducted a comprehensive multi-omics analysis of IDH-wildtype GBMs from three publicly available datasets. Prognostic metabolism-related genes were used to define transcriptional subtypes, which were validated in independent datasets and patient-derived cell (PDC) models. Functional assays and drug sensitivity studies were performed to explore therapeutic relevance.

Results: We identified three distinct metabolic subtypes: M1, enriched for synaptic signaling and amino acid metabolism, exhibited leading-edge anatomical features; M2, characterized by mitochondrial metabolism and cell cycle activity, was associated with favorable survival; and M3, marked by hypoxia, immune activation and suppression, and broad metabolic pathway engagement, correlated with poor prognosis. These subtypes were reproducible across cohorts and faithfully recapitulated in PDC models. Metabolomic profiling confirmed distinct subtype-specific metabolic signatures. Notably, M3 cells showed high sensitivity to inhibitors targeting glycosaminoglycan degradation, nicotinamide metabolism, and retinoic acid pathways in both in vitro and in vivo models.

Conclusion: Our study defines three biologically and clinically relevant metabolic subtypes of IDH-wildtype GBM. This classification reveals distinct metabolic programs and therapeutic vulnerabilities, providing a framework for precision metabolism-targeted strategies in glioblastoma.

Background: Meningioma brain invasion encumbers surgical resection and increases the risk of tumor recurrence, but the molecular mechanisms underlying this process are poorly understood.

Methods: To identify molecular and cellular features of brain-invasive meningiomas, we (1) analyzed bulk RNA sequencing data from 199 meningiomas, including 33 brain-invasive tumors, (2) analyzed patient-matched single-cell RNA sequencing data of spatially mapped meningioma samples from the tumor core or brain-tumor interface (BTI), and (3) performed spatial transcriptomic sequencing of brain-invasive meningioma samples. Multiplexed immunofluorescence (IF) was used to validate bioinformatic spatial expression patterns. Functional interactions between meningioma cells and neurons were studied in meningioma/neuron co-cultures using confocal microscopy, multi-electrode array recordings, and live cell calcium imaging.

Results: Transcriptomic analyses showed conserved enrichment of TGM2, S100A11, ZYX, and PDGFRA at the BTI across bulk, single-cell, and spatial RNA sequencing datasets. The expression of these genes at the BTI was confirmed using multiplexed IF, and single-cell bioinformatic and microscopy analyses further demonstrated enrichment of macrophages at the BTI. Co-culture assays showed neuronal hyperexcitability and increased proliferation of meningioma cells, suggesting functional communication between meningioma cells and the tumor microenvironment may contribute to meningioma growth in cases with brain invasion.

Conclusions: Meningioma brain invasion is defined by molecular remodeling of tumor cells and functional interactions within the tumor microenvironment.

Background: Glioblastoma (GBM) is characterized by extensive tissue hypoxia. This hypoxic microenvironment drives chemoresistance and promotes aberrant vascularization, critically limiting the efficacy of temozolomide (TMZ) and bevacizumab (BEV). Here, we report EPIC-0502, a novel small-molecule competitive antagonist that inhibits hypoxia signaling while sensitizing GBM to both TMZ and BEV.

Methods: EPIC-0502 was identified through molecular dynamics simulation. Its target blocking effect was validated via non-targeted metabolomics, stable isotope tracing-based metabolic flux analysis, and pull-down assays. The mechanisms underlying EPIC-0502 activity were elucidated by Western Blot (WB), Co-Immunoprecipitation (Co-IP), ELISA, Seahorse assays, and Immunofluorescence (IF). The sensitizing effects of EPIC-0502 on TMZ and BEV were evaluated in orthotopic GBM models.

Results: EPIC-0502 inhibited α-ketoglutarate (α-KG) to succinate conversion, depleting cytoplasmic succinate levels and inhibiting phosphoglycerate kinase 1 (PGK1) succinylation and phosphorylation, which significantly attenuated glycolysis. Furthermore, EPIC-0502 destabilized HIF1α by promoting hydroxylation-dependent ubiquitination, while impairing its transcriptional activity. Through HIF1α degradation, EPIC-0502 enhanced GBM sensitivity to TMZ via E2F1 downregulation and reversed hypoxia-induced vascular endothelial growth factor A (VEGFA) overexpression, potentiating the antiangiogenic efficacy of BEV. Collectively, these actions enable EPIC-0502 to synergistically enhance the therapeutic efficacy of TMZ/BEV combination.

Conclusion: Based on EPIC-0502-driven HIF1α degradation that overcomes BEV resistance and synergizes with TMZ, we propose the novel VITA-GBM regimen comprising: Vascular targeting (BEV), Inhibition of hypoxia signaling (EPIC-0502), TMZ chemotherapy, and Alignment of synergistic mechanisms. This strategy enhances the efficacy of first-line therapies and provides a promising approach to improve overall survival in GBM patients.

Background: Scarce T cell infiltration, immunosuppressive tumor-associated macrophages and ineffective drug delivery drive glioma progression and limit treatment efficacy. Mapping immunotherapy distribution by multimodality imaging might be a biomarker that could aid tumor monitoring and guide therapy development.

Methods: To assess drug delivery, we developed a MRI-lightsheet microscopy platform (MR-LSM) to monitor immunotherapy at the cellular level in two immunocompetent glioma models (Gl261, SB28). The atezolizumab (PD-L1 inhibitor) subgroup of the multicenter N2M2/NOA20 trial in MGMT unmethylated GBM patients was assessed by CNN analysis and correlated to progression free survival.

Results: In contrast to the conventional Gl261 glioma model, SB28 gliomas are characterized by poor immunogenicity and resistance to Toll-like receptor (TLR) 7 targeted therapy delivered by CDNP-R848 nanoparticles. SB28 resistance is driven by microvascular pathology, vasogenic edema and drug off-targeting to peritumoral edema and white matter tracts. Vascular endothelial growth factor (VEGF) inhibition in conjunction with irradiation and dual immunotherapy (DIR) targeting innate (CDNP-R848) and adaptive immunity (anti-CTLA-4) breaks resistance, increases survival and reverses drug off-targeting. Mechanistically, tumor control is orchestrated by vascular normalization, enhanced CD8+ T cell influx and a proinflammatory shift of myeloid cells along with strong IL-12/IL-13 upregulation. In a translational analysis of the multicenter N2M2/NOA20 trial we validate that edema and microvascular pathology are associated with poor prognosis in glioblastoma patients treated with checkpoint immunotherapy and that patients without edema have increased PFS.

Conclusions: We develop a customizable imaging platform to map drug delivery to glioma with broad applicability in neuroscience and neurooncology.