BACKGROUND:Reirradiation is used for children and adolescents with recurrent ependymoma after prior surgery and focal irradiation. This study assessed the long-term benefits and risks of a second course of fractionated radiotherapy, patient selection, factors associated with progression-free survival (PFS) and overall survival (OS), and the role of craniospinal irradiation (CSI) at first recurrence. METHODS:From July 1994 to January 2024, 150 pediatric ependymoma patients at St. Jude Children's Research Hospital received a second course of fractionated radiotherapy. Sixty-four were enrolled in a prospective trial. Inclusion required conventional fractionation (≥50.4Gy) for both courses, with CSI for metastatic disease. Kaplan-Meier estimates measured PFS and OS, Cox models assessed associations with covariates, and competing risks analysis evaluated necrosis and death from complications. RESULTS:At 10 and 20 years, PFS/OS for the cohort were 19.5%/34.3% and 9.0%/13.1%, respectively. Females had significantly better outcomes, and survival varied by initial failure pattern. No significant difference in PFS (p = 0.1351) or OS (p = 0.2705) was found between focal irradiation and CSI for patients with local failure. Necrosis was higher with proton therapy versus photons; grade 3 necrosis after reirradiation occurred in 19.9%. The 10-year cumulative incidence of death from complications or secondary tumors was 8.5%. CONCLUSIONS:A second course of conventionally fractionated radiotherapy can extend survival in recurrent pediatric ependymoma, but prognosis remains poor, especially for those with combined local and distant failure or adverse features. CSI did not improve outcomes for local failures. Proton therapy increased necrosis risk, emphasizing the need for careful selection and follow-up.
BACKGROUND:In glioblastoma (GBM), epidermal growth factor receptor (EGFR) amplification, one of the most prevalent genetic alterations, often occurs on extrachromosomal DNAs (ecDNAs) that contain amplified oncogenes and regulatory elements, driving tumor progression. Despite the central oncogenic role of EGFR amplification, therapeutic strategies targeting EGFR have demonstrated limited clinical efficacy, suggesting that additional mechanisms may underlie EGFR-driven GBM malignancy and treatment resistance. Long non-coding RNAs (lncRNAs) are critical regulators in cancer; however, the roles of EGFR-associated lncRNAs-particularly those localized on ecDNA-in GBM tumorigenicity and therapeutic resistance remain poorly understood. METHODS:Transcriptomic and genomic analyses were performed to identify lncRNAs co-amplified with EGFR. Biochemical and molecular biological studies were carried out to reveal the mechanisms. In vivo xenograft models were used to evaluate the tumorigenicity and the therapeutic efficacy of combination treatment strategies. RESULTS:The lncRNA EGFR long non-coding downstream RNA (ELDR) was co-amplified with EGFR on ecDNA and chromosomes and was associated with poor prognosis in glioma. ELDR promoted GBM tumorigenicity through a BMI1-dependent epigenetic mechanism operating in parallel with canonical EGFR signaling. Mechanistically, ELDR interacted with purine-rich element-binding protein A (PURA), disrupted the inhibitory PURA-BMI1 interaction, and thereby enhanced the activity of BMI1, a core component of Polycomb repressive complex 1 (PRC1). Therapeutically, combining a BMI1 inhibitor or ELDR-targeting antisense oligonucleotides (ASOs) with an EGFR inhibitor erlotinib significantly enhanced antitumor efficacy in preclinical models of EGFR -amplified GBM with high ELDR expression. CONCLUSION:EGFR co-amplified ELDR promotes GBM tumorigenicity by enhancing BMI1 activity. Targeting the ELDR-BMI1 axis in combination with EGFR inhibition represents a promising therapeutic strategy for a subset of EGFR -amplified GBMs with high ELDR expression.
BACKGROUND:Diffuse middle glioma (DMG or DIPG) is a fatal pediatric brain tumor. Although chimeric antigen receptor (CAR) T-cell therapy shows promise, clinical outcomes remain inconsistent due to premature exhaustion, underscoring a critical need to improve CAR-T persistence. A major barrier to CAR-T efficacy is antigen-independent tonic signaling, yet the extent to which tonic signaling shapes CAR-T durability and clinical outcomes, particularly in DMG, remains incompletely defined. METHODS:Using a clinically investigated B7-H3 MGA271-based CAR as a reference platform, we generated alternative B7-H3 CARs incorporating either a human codon-optimized 376.96 (B7H3.BC) or Hu8H9 scFv antigen binding domain to systematically assess scFv-dependent effects on tonic signaling and therapeutic efficacy. CAR-T cells were evaluated using integrated in vitro and in vivo functional assays, alongside multi-omics profiling and computational modeling. We further derived a tonic signaling-associated gene signature and evaluated its predictive performance across independent clinical datasets. RESULTS:B7H3.BC CAR-T cells exhibit markedly restrained tonic signaling compared with MGA271- and Hu8H9-based counterparts, accompanied by superior antitumor activity and enhanced persistence across patient-derived DMG cells. Integrated multi-omics and single-cell profiling further identified a tonic signaling-associated gene signature that outperforms conventional T-cell exhaustion signatures in predicting therapeutic efficacy across multiple clinical trials, including DMG and other tumors. CONCLUSIONS:Our findings establish that scFv-dependent modulation of tonic signaling critically governs CAR-T persistence and antitumor efficacy in DMG. By linking CAR design to transcriptional and epigenetic programs, our study provides a principle-based and predictive framework to inform rational CAR engineering and improve therapeutic outcomes.
BACKGROUND:Triple negative breast cancer (require) new treatment strategies due to poor responses to current therapies. While myeloid SIRPα mediates immunosuppression, its cancer intrinsic role remains poorly understood. METHODS:Human breast cancer scRNAseq profiles were used to examine SIRPα expression across different cell populations and subtypes. TNBC brain-tropic cells were injected into the mouse mammary fat pad for the orthotopic tumor model, and intracardiac-injected for brain metastasis models. Bulk RNA sequencing was used to determine SIRPα-regulated pathway. Stably SIRPα overexpressed and knockout TNBC cell lines were established to determine SIRPα intracellular regulation. Digital spatial profiling was utilized to investigate the orthotopic and brain metastasis tumor immune microenvironment. RESULTS:Human single-cell data showed that SIRPα levels increased in malignant TNBC epithelial cells. We observed that SIRPα is upregulated in patient breast-to-brain metastatic lesions. SIRPα is overexpressed in TNBC brain-tropic cells compared to parental cells. Bulk RNA-Seq showed that targeting SIRPα affects genes involved in mitochondrial dynamics, and that SIRPα upregulates mitochondrial fission and induces metastasis through the SHP2/Erk/Drp1 signaling pathway. In vivo, overexpression of SIRPα in cancer cells significantly increases TNBC systemic metastasis. Next, spatial proteomics revealed changes in the immune microenvironment associated with the SIRPα-regulated ECM protein fibronectin. Fibronectin induces microglial tolerance by impairing inflammatory signaling and metabolic reprogramming, allowing cancer to escape microglial immunosurveillance. Most importantly, SIRPα inhibition reduced TNBC brain metastatic lesions in mouse metastasis models. CONCLUSION:: Cancer-intrinsic SIRPα promotes TNBC brain metastasis through increased mitochondria fission and triggering microglia tolerance, and targeting SIRPα reduces brain metastasis.
BACKGROUND:Glioblastoma (GBM) is a highly aggressive brain tumor for which cell-free DNA (cfDNA) has shown promise as a minimally invasive biomarker, yet the biological processes governing cfDNA release and composition in GBM remain incompletely understood. METHODS:We investigated cfDNA release dynamics, fragmentation patterns, variant allele frequencies (VAF), and copy number profiles under controlled experimental conditions using patient-derived GBM cultures. RESULTS:Longitudinal sampling of conditioned media from monocultures revealed progressive increases in cfDNA yield that correlated more strongly with viable cell numbers than with cell death, suggesting that cfDNA production in these models is not solely driven by apoptosis. In co-culture experiments combining GBM cells with normal human astrocytes (NHA), distinct tumor- and astrocyte-specific variants enabled deconvolution of mixed-cell populations, and cfDNA composition shifted over time, consistent with increasing astrocyte death under competitive co-culture conditions. Temozolomide (TMZ) treatment altered cfDNA release dynamics, shifting the dominant source from viable cells to cell-death-associated pathways, accompanied by increased cfDNA yield, nucleosomal fragmentation, and evidence of reduced variant diversity under therapeutic pressure. Tumor-derived cfDNA was also detected and deconvolved from plasma in GBM orthotopic xenograft models, with copy number profiles recapitulating those of the parental tumor cells. CONCLUSION:These findings suggest that cfDNA composition is shaped by tumor proliferation, microenvironmental context, and therapeutic stress, establishing a preclinical foundation for interpreting cfDNA-based liquid biopsy signals in GBM.
Magnetic resonance imaging (MRI) is essential for post-treatment surveillance of patients with intracranial central nervous system (CNS) tumours. However, interpretation is often complicated due to post radiotherapy MRI abnormalities. Current literature demonstrates substantial heterogeneity in terminology and definitions used to describe these MRI abnormalities, limiting clinical decision-making and comparability across studies. To address this, an international multidisciplinary Delphi consensus was conducted within the Radiation Imaging and Neuro-Oncology Group (RING). Questionnaires were developed by the steering committee and distributed to experts in radiation oncology, neuroradiology, neuro-oncology, medical oncology, and neurosurgery. A three-round Delphi method was employed, with consensus defined as ≥ 75% agreement. Consensus was reached on the applicability and definitions with adoption of the term Treatment-Related Imaging Abnormality (TRIA). Clear definitions for potential and confirmed TRIA were established. Subcategorization based on imaging features all demonstrated high agreement. For consistent application of the framework minimal essential elements for MRI request forms were identified. The final consensus was endorsed by ESTRO, ESNR and EORTC. This Delphi consensus provides a standardized framework for MRI abnormalities following radiotherapy for intracranial CNS tumours. The framework aims to harmonize reporting, support clinical decision-making, and improve comparability in future neuro-oncology research. Central nervous system neoplasms - Radiotherapy - Magnetic resonance imaging - Delphi Technique - Treatment-Related Imaging Abnormality (TRIA).
BACKGROUND:Glioblastoma (GBM) is the most common adult primary brain malignancy. Recent studies demonstrate that temozolomide (TMZ) facilitates the persistence of quiescent glioma stem cells (GSCs), which are responsible for GBM recurrence. An ideal therapy should eradicate both proliferating cells and GSCs. Abexinostat (Abx), a histone deacetylase inhibitor, was identified through connectivity mapping to target the specific GBM signature. Here, we demonstrate the anti-proliferative effect of Abx on both differentiated cells and GSCs. METHODS:Using patient-derived tumor cultures (PDCs) to test Abx in vitro, ATAC-seq identified chromatin accessibility. Single-spheroid and alkaline phosphatase staining assays were used to test stem cell self-renewal. Aldehyde dehydrogenase activity distinguished mesenchymal GSCs. The efficacy of Abx with TMZ was evaluated in GSC-expressing CK9751 PDC and mesenchymal patient-derived xenografts (PDXs). RESULTS:In PDCs (CK9495 and CK9751), Abx decreased the DNA repair machinery (RAD51, CHK1, Ku70, and MGMT) and induced apoptosis. Focused ATAC-seq analysis for promoters of DNA repair (RAD51, Ku70, CHK1, and BRCA1) and stemness (CD44, KLF4, c-Myc, and BMI1) revealed Abx decreased chromatin accessibility. Abx decreased stem cell self-renewal and reduced the mesenchymal stem cell signature (CD44, ALDH1A3 expression, and ALDH1 activity) in vitro GBM models. Abx reduced tumor growth and stemness markers in CK9751 PDC and mesenchymal PDXs. CONCLUSION:Abx reduced both DNA repair machinery and GSC markers by decreasing chromatin accessibility. Abx reduced tumor growth and mesenchymal GSCs in vitro and in vivo in GBM PDC and PDX models, supporting Abx's potential to prevent GSC-mediated therapy resistance and improve patient survival.
BACKGROUND:In glioblastoma studies, the presence of measurable disease is often required for trial eligibility. While response assessment according to RANO 2.0 relies on MRI, the recently introduced PET RANO 1.0 criteria allow standardized evaluation based on amino acid PET. This study compares the frequency of measurable disease according to PET RANO 1.0 vs. RANO 2.0 criteria at key enrollment timepoints of clinical trials. METHODS:In this retrospective, single-center study, we included patients with IDH-wildtype glioblastoma who underwent both [¹⁸F]FET PET and MRI, after standard first-line radiotherapy (time-point T0) (defined per RANO 2.0) or at first progression (time-point T1). Two independent raters evaluated measurable disease using PET RANO 1.0 and RANO 2.0 criteria. Further, tumor size, target lesions and tracer uptake metrics were analyzed. RESULTS:In total 322 patients were included, 112 at T0 (median age: 59 years, IQR 54-69), and 210 at T1 (median age: 59, IQR 53-67). On MRI, measurable disease was identified in 57/112 patients (50.9%) at T0 and in 137/210 patients (65.2%) at T1 (median sum of products of cross-sectional diameters: 143mm2; 187mm2). On PET, significantly more cases with measurable disease were detected: 102/112 patients, (91.1%) at T0 and 201/210 patients (95.7%) at T1 (median volumes: 9.86cm³; 14.3cm³) (p = 0.001). CONCLUSION:PET RANO 1.0 detects a substantially larger subset of patients with measurable disease compared to RANO 2.0. These findings warrant prospective validation of PET-based measurable disease as an inclusion criterion for clinical trials in IDH-wildtype glioblastoma, with the potential to broaden trial eligibility.
BACKGROUND:Central nervous system (CNS) tumors represent the leading cause of pediatric cancer-related deaths. Primary treatment often involves neurosurgical tumor resection. Accurate diagnosis is crucial to perform the best-suited extent of resection. Recently, we published Sturgeon, an AI-based validated intraoperative nanopore sequencing tool, delivering accurate methylation-based diagnoses during surgery. Although several other nanopore sequencing strategies have been described, clear evidence of clinical impact remains critically absent. Here, we report a care evaluation analyzing the impact of Sturgeon on real-time pediatric neurosurgical decision-making. METHODS:Since May 2023, a dual diagnostic neuro-oncological workflow incorporating intraoperative frozen section analyses and ultra-fast nanopore sequencing using Sturgeon has been fully implemented as standard of care at the Princess Máxima Center for Pediatric Oncology in the Netherlands. This intraoperative diagnostic workflow has been applied to all pediatric patients (<19 years of age) with primary CNS tumors and the multidisciplinary indication for tumor resection surgery. RESULTS:Sturgeon delivered correct diagnoses in 82 out of 94 consecutive patients (87.2%, <90 minutes), no diagnosis in 11.7% and one incorrect diagnosis (1.1%). The diagnosis obtained by Sturgeon supported the intended surgical strategy (85.7%) or changed the strategy (14.3%) toward a more aggressive or limited resection. This contributed to a low complication rate and less second-look surgeries. Earlier communication of the histomolecular diagnosis to patients and their families was observed. CONCLUSIONS:Intraoperative use of Sturgeon provides essential guidance toward the most optimal neurosurgical strategy for pediatric CNS tumors and thereby has great potential to contribute to better clinical outcome.
BACKGROUND:Childhood scalp irradiation for tinea capitis (TC) increases the long-term risk of intracranial meningiomas. It remains unclear whether prior TC irradiation affects meningiomas' response to stereotactic radiosurgery (SRS). We compared TC-irradiated and sporadic meningiomas treated with SRS. METHODS:Among 539 meningioma patients treated with SRS from 2010-2023, 204 met criteria for volumetric analysis (median follow-up 64.6 months, IQR 32.8-107.8). Of these, 61 (29.9%) had childhood scalp irradiation for TC, while 143 (70.1%) had no prior cranial irradiation. Tumor volumes were measured on T1-weighted gadolinium-enhanced MRI baseline and at last follow-up, or prior to surgery. Treatment response was assessed as percent volume change, as a binary study-defined "good response" (≥29% reduction), and RANO-aligned categories. Predictors of response and surgical intervention were evaluated using multivariable regression. RESULTS:TC-irradiated patients were older (median 67.6 vs. 62.8 years, P < .001) and more commonly had multiple meningiomas (73.8% vs. 11.9%, P < .001) than non-irradiated patients. Baseline tumor volume was similar between groups (P = .516), as was the need for surgical resection (P = .535). Multivariable analysis showed that TC irradiation independently predicted poorer volumetric response (a + 38.7% relative volume change, P = .026) and a lower likelihood of achieving the study-defined "good response," although this was not statistically significant. TC irradiation was not associated with progression-free survival. CONCLUSIONS:Childhood TC irradiation-related meningiomas are a distinct subgroup characterized by multifocality and reduced volumetric response to SRS. These findings suggest a potentially treatment-resistant phenotype, supporting the need for individualized management.
