Neuro-oncology最新文献

Background: Immunotherapy has yet to make significant gains in glioblastoma (GBM) treatment, due in part to GBM-mediated immune suppression. Increasing evidence points to critical roles for tumor-derived extracellular vesicles (EVs) and immunosuppressive myeloid cells as key factors in this process.

Methods: Immunophenotyping of the tumor-immune microenvironment was performed using ultrasonic aspirate collected during GBM resection by high-dimensional flow cytometry. EVs collected from patient-derived GBM cell lines were used to condition myeloid cells collected from healthy donors to generate immunosuppressive myeloid cells. siRNA was used to knockdown TIGIT and/or NLRP3 expression prior to EV conditioning. T cell co-culture studies were performed with donor-matched T cells.

Results: Immune phenotyping of the tumor microenvironment and EV-conditioned myeloid cells revealed similar immunomodulatory protein expression across myeloid cell populations, with particularly elevated TIGIT expression. Knockdown of TIGIT reduced the immunosuppressive polarization of myeloid cells, resulting in improved T cell function. This finding proceeded in an NLRP3-dependent manner, with substantial co-expression of TIGIT and NLRP3 expression prior to knockdown, and concomitant knockdown of NLRP3 abrogating the effect of TIGIT knockdown. TIGIT expression correlated with increased IL-13 expression, and IL-13 blockade unmasked a pro-inflammatory myeloid cell phenotype.

Conclusion: TIGIT expression in myeloid cells in the GBM microenvironment is a functional marker of immunosuppressive activity, with TIGIT knockdown reducing IL-13 expression and unmasking the pro-inflammatory activity of NLRP3. This study bolsters our understanding of the immunosuppressive complexities of the GBM microenvironment, and supports attenuation of immunosuppressive myeloid cell activity as a strategy to restore immune function in GBM.

Background: Precise delineation of non-contrast-enhancing tumor (nCET) in glioblastoma (GB) is critical for maximal safe resection, yet routine imaging cannot reliably separate infiltrative tumor from vasogenic edema. The aim of this study was to develop and validate an automated method to identify peritumoral subregions compatible with nCET and assess its prognostic value.

Methods: Pre-operative T2-weighted and FLAIR MRI from 940 patients with newly diagnosed GB in four multicenter cohorts were analyzed. A deep-learning model segmented enhancing tumor, edema and necrosis; a non-local, spatially varying finite mixture model was applied to identify edema subregions characterized by relatively lower FLAIR hyperintensity, hypothesized to reflect nCET-related tissue. The ratio of these subregions to total edema volume defined the T2/FLAIR Heterogeneity Index (TFHI). Associations between TFHI and overall survival (OS) were examined with Kaplan-Meier curves and multivariable Cox regression.

Results: Higher TFHI values stratified patients with shorter OS. In the NCT03439332, TFHI above the optimal threshold was associated with a twofold increased hazard of death (hazard ratio (HR) 2.07, 95 % confidence interval 1.33-3.21; p = 0.0013) and a reduction in median survival of 98 days. Significant, though smaller, prognostic effects were confirmed in GLIOCAT & BraTS (HR= 1.37; p = 0.047), OUS (HR = 1.37; p = 0.0032) and pooled analysis (HR= 1.26; p = 0.0008). TFHI remained an independent predictor after adjustment for age, extent of resection and MGMT methylation.

Conclusions: We present a reproducible, server-hosted tool for automated identification of imaging-defined, putative nCET-related peritumoral subregions and TFHI biomarker extraction that enables independent prognostic stratification. This approach provides a quantitative framework for studying peritumoral heterogeneity in GB.

Background: Glioblastoma (GBM) is a lethal brain tumor with limited treatment options, largely due to profound immune suppression within the tumor microenvironment (TME), the failure of current immunotherapies to restore CD8+ T cell function, and persistence of glioma stem cells (GSCs) after treatment. Oncolytic Zika virus (ZIKV) is a promising therapeutic that selectively targets GSCs and remodels the TME to enhance anti-tumor CD8+ T cell responses. In this study we investigated how ZIKV efficacy in GBM is driven through monocytes.

Methods: We performed single-cell RNA sequencing and T cell receptor (TCR) sequencing to evaluate CD8+ T cell responses following ZIKV treatment. We used CellChat to define signaling networks between ZIKV-activated CCR2+ monocytes and CD8+ T cells in the TME. We used syngeneic, immunocompetent murine GBM models to validate mechanisms in vivo, applying genetic and antibody-based approaches to impair CCR2+ monocyte trafficking and function.

Results: ZIKV induced clonal expansion of tumor-infiltrating CD8+ T cells enriched in granzyme B and perforin-1, with reduced expression of exhaustion markers. CCR2+ monocytes were essential for the recruitment, proliferation, and effector functions of anti-tumor CD8+ T cells in the TME. Disruption of monocyte trafficking or function impaired these responses, diminishing cytotoxic activity and T cell recruitment.

Conclusions: ZIKV-driven activation and recruitment of CCR2+ monocytes supports robust anti-tumor CD8+ T cell responses by enhancing cytotoxicity and limiting exhaustion. These findings highlight the previously unappreciated therapeutic potential of modulating monocyte-T cell crosstalk to overcome immune suppression in GBM.

Glioblastoma (GBM) is a highly aggressive and metabolically adaptable brain tumor characterized by profound cellular heterogeneity and therapy resistance. Recent research has uncovered the phenomenon of horizontal mitochondrial transfer (HMT) between GBM cells and their microenvironment, particularly astrocytes, which contributes to tumor progression, metabolic reprogramming, and treatment resistance. This review summarises current knowledge on mitochondrial exchange in GBM via tunneling nanotubes (TNTs), tumor microtubes (TMs) and potentially via extracellular vesicles (EVs). It also explores the functional consequences of HMT, including enhanced oxidative phosphorylation (OXPHOS), increased tumorigenicity, and altered therapeutic responses. This review highlights the need for further investigation into the molecular drivers and context-specific outcomes of mitochondrial transfer in GBM, with implications for novel therapeutic strategies.

Background: The benefits of offering first- plus third-generation epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) for treatment-naive EGFR-mutant non-small cell lung cancer patients (NSCLC) with brain metastases (BMs) are unknown. This trial aims to assess the feasibility, safety, and efficacy of icotinib plus aumolertinib in these patients.

Methods: The phase I/II trial (ChiCTR2100044216) employed a 3 + 3 dose-escalation and dose-expansion design targeting EGFR-mutant NSCLC patients with baseline measurable BMs. Primary endpoints were the recommended phase II dose (RP2D) and feasibility. Major secondary endpoints included median overall survival (OS), systemic and intracranial progression-free survival (PFS and iPFS), objective response rate (ORR and iORR), and safety profile.

Results: 24 eligible patients were evaluated with a median follow-up of 41.4 months. The RP2D was 125 mg icotinib three times daily plus 110 mg aumolertinib once daily. Median PFS was 21.1 months (95% CI 14.6-27.6 months) and median OS was 40.8 months (95% CI 29.1-52.5). ORR was 95.8% and the disease control rate (DCR) was 100%. Median iPFS was 22.5 months (95% CI 17.5-27.6 months) with iORR of 91.7% and intracranial DCR of 100%. For safety profile, grade ≥3 treatment-related adverse events (TRAEs) occurred in 37.5% of patients. The most common any-grade TRAEs were increases in alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine kinase (CK), and rash.

Conclusions: The combination of aumolertinib and icotinib shows encouraging efficacy and a tolerable safety profile in patients with EGFR-mutant NSCLC and BMs, supporting its potential as a therapeutic option warranting further investigation.

Background: Medulloblastoma (MB) is a malignant cerebellar tumor primarily affecting children. SHH MB with GLI2 amplification is associated with a particularly poor prognosis. Although GLI2 amplification is clinically recognized, its role in driving SHH-MB remains unclear.

Methods: We generated novel mouse models of GLI2-amplified MB to investigate the role of GLI2 in driving tumorigenesis and assessed their similarity to human tumors using immunohistological and scRNA-seq analyses. Additionally, we examined the spatiotemporal window of tumor development using our mouse models and explored the mechanisms underlying the susceptibility of embryonic cerebellar granule cell progenitors (GCPs) to GLI2-induced tumorigenesis through scRNA-seq analysis. We further investigated the involvement of MAPK pathway in GLI2-driven tumorigenesis and progression by genetically disrupting the pathway.

Results: We demonstrate that GLI2 is a primary oncogenic driver in SHH-MB, with its overexpression driving embryonic Math1+ progenitor cells to form SHH-MB. The resulting GLI2-driven tumors closely resemble human GLI2-amplified SHH-MB cellularly and molecularly. Additionally, we determined that embryonic Math1+ GCPs at E13.5-E15.5 are the most susceptible to tumor initiation with GLI2 overexpression alone. In postnatal Math1+ GCPs, additional Trp53 inactivation is required for GLI2-induced tumor formation. scRNA-seq analysis reveals MAPK pathway enrichment in embryonic GCPs and GLI2-driven tumors. Functional studies show that knocking down MEK1/2 in Math1+ progenitor cells or GLI2-driven MB cells prevents tumorigenesis and tumor progression, respectively.

Conclusions: Our studies uncover the developmental origins and molecular mechanisms underlying GLI2-amplified SHH-MB. We also reveal that the MAPK pathway plays a critical role in GLI2-driven SHH-MB tumorigenesis and progression.