Neuro-oncology最新文献

Background: Intracranial mesenchymal tumors, FET::CREB fusion-positive (ICMT), show fusions involving FET RNA-binding protein family genes (EWSR1 or FUS) and CREB family of transcription factors (ATF1, CREB1 or CREM). The methylation signature(s), gene expression characteristics and clinical behavior of this important tumor type require further characterization.

Methods: We study the methylation profiles of 81 ICMT cases (61 newly profiled cases and 20 cases from publicly available sources). Clinicopathologic and genomic data were recorded for each case when available.

Results: ICMT showed a relatively distinct methylation signature compared to related tumors. Among the 65 cases where fusion types were documented, the identified fusions included EWSR1::ATF1 (25 cases), EWSR1::CREB1 (12 cases), EWSR1::CREM (21 cases), FUS::CREM (3 cases) and SMARCA2::CREM (4 cases). We confirmed the prior description of two distinct subgroups of ICMT (subclasses A and B). The majority of the cases belonged to subclass A (n = 69; 85%), which showed higher median age compared to subclass B patients (26 years vs. 15 years). Subclass B cases (n = 12; 15%) showed shorter progression-free survival (p < 0.01). Gene expression analysis of ICMT showed key overexpressed markers in ICMT, with significant CREM overexpression regardless of fusion type, when compared to either meningioma alone, or a larger group of CNS tumors.

Conclusions: This work provides further characterization of ICMT as an important CNS mesenchymal neoplasm that is prone to tumor recurrence, showing 2 prognostically relevant methylation subclasses, and warranting diagnostic distinction from other epigenetically and histologically related tumors. ICMTs show substantial overexpression of the CREM gene, independent of fusion type.

Background: High-grade meningiomas (HGMs) recurring after X-ray treatment show poor prognosis. We assessed the effectiveness and safety of boron neutron capture therapy (BNCT) in patients with refractory recurrent HGMs.

Methods: This phase II investigator-led randomized controlled trial utilized an accelerator-based BNCT system to treat refractory recurrent HGMs. Patients were randomly assigned in a 2:1 ratio to the BNCT (12 patients) and control (6 patients) arms. Progression-free survival (PFS) judged by an independent third-party committee was the primary endpoint and PFS judged by the investigators and overall survival of the BNCT arm were the secondary endpoints. The control arm received rescue BNCT if they show disease progression.

Results: Three and two patients with World Health Organization (WHO) grade 3 disease were assigned to the BNCT and control arms, respectively; the remaining patients had WHO grade 2 disease. Median PFS (primary endpoint) was 14.4 months (95% confidence interval (CI): 7.9-26.4) in the BNCT arm and 1.4 months (95% CI: 1.0-9.0) in the control arm. Median PFS (secondary endpoint) was 14.7 months (95% CI: 7.6-22.8) in the BNCT arm and 1.5 months (95% CI: 1.0-9.0) in the control arm. The differences were statistically significant (log-rank test, P = 0.0157 and P = 0.0002, respectively). Five patients in the control arm received rescue BNCT. The objective response rate in the BNCT arm was 27.3%.

Conclusions: BNCT is an effective treatment for refractory recurrent HMGs. Compared with conventional therapy, PFS in both primary and secondary endpoints were considerably improved.

Background: High-dose methotrexate (MTX)-based chemotherapy is the mainstay of treatment of primary central nervous system lymphoma (PCNSL). Only ∼60% of patients achieve a complete response to first line therapy with frequent relapses. The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib has shown promising antitumor activity in recurrent/refractory PCNSL. Methods: The goal of the current single-center phase 2 trial was to explore whether the addition of ibrutinib to the combination of rituximab, methotrexate, procarbazine, and vincristine ((R-MVP/i) increases complete response rate (CCR).

Results: Thirty newly diagnosed PCNSLs were enrolled; median age 69 (range 41-79), median ECOG = 1. 29 patients completed R-MVP/i, 1 withdrew consent after 2 cycles.A CR/CRu was achieved in 29 patients and a partial response in 1 for a CRR of 29/30 (97%, 95% CI : 83.3%, 99.8%)). Treatment was well tolerated with no grade 5 toxicity was observed. Eight patients experienced 13 grade 4 toxicities (lymphopenia (n = 3), neutropenia (n = 4), thrombocytopenia (n = 3) white cell count decrease (n = 3)). The most common toxicities were thrombocytopenia, anemia, lymphopenia and liver enzyme elevations. No Aspergillus or Pneumocystis infections occurred. No refractory disease was observed. For the 29 patients completing the trial, 19 received consolidation with cytarabine (Ara-C), 8 autologous stem cell transplant, 1 rituximab maintenance and 1 was observed without maintenance or consolidation. At a median follow up of 25.1 months (range 3.3-49.2), the median progression-free (PFS) and overall survival (OS) was not reached with a 2-year PFS of 84.2% (95% CI: 62.7%-93.9%).

Conclusions: R-MVP/i was well tolerated and associated with excellent disease control and survival.

Background: IDH1R132H is the defining mutation of low-grade gliomas (LGGs), inflicting broad epigenetic rewiring that leads to malignant transformation. Recent studies demonstrated that cell fate change from astrocyte to LGG is accompanied by redistribution of H3K4 methylation. By modulating H3K4-methyltransferase KMT2A in a conditionally IDH1R132H-expressing human astrocyte model system, we sought to define requirements of IDH1R132H dependent gliomagenesis and identify novel therapeutic targets.

Methods: Using KMT2A inhibitor MM-102, we targeted H3K4me3 in IDH1R132H -expressing astrocytes, profiling L1CAM expression, proliferation, clonogenicity, invasion and migration, transcriptional and translational changes. Findings were validated in patient-derived IDH1R132H glioma lines with shRNA-mediated knockdown. Epigenetic transformation was characterized with CUT&Tag and MethylationEPIC. Downstream targets were assessed utilizing siRNAs.

Results: KMT2A inhibition significantly decreased L1CAM expression and led to broad transcriptional downregulation, including LGG marker genes. Analyses of transcriptomics and proteomics pointed to altered lipid metabolism and migratory capacity. Phenotypic characterization showed impaired invasion, migration and proliferation. We observed significantly reduced deposition of H3K4me3 at promoters of DEGs and enhanced global DNA methylation. We identified SCD as putative KMT2A-dependent effector whose knockdown reduced clonogenicity. In patient-derived models, KMT2A suppression impaired viability and spheroid growth in vitro; however, in an orthotopic TS603 model, knockdown shortened survival, indicating stage- and context-dependent effects.

Conclusions: Disrupting KMT2A-mediated H3K4me3 reshapes the epigenome and attenuates LGG-relevant programs and phenotypes in vitro, supporting a strong role in tumor initiation. In vivo, the TS603 survival result highlights context-dependent maintenance and motivates cautious, microenvironment-aware therapeutic exploration of the KMT2A axis and downstream targets such as SCD.

Background: The prognosis of patients with recurrent WHO grade 4 glioma is poor, particularly in glioblastoma (GBM), which has a median survival of approximately 6 months and no effective treatment options. We evaluated the short-term (28-day) safety and efficacy of ON-01, an engineered recombinant oncolytic herpes simplex virus type-1, in patients with recurrent WHO grade 4 glioma.

Methods: In this single-arm, phase 1/2 clinical trial, eligible patients received intratumoral injections of ON-01 under stereotactic guidance. The primary endpoint was to assess the short-term safety profile of ON-01 treatment. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and the 2-year OS rate. An exploratory objective was to identify tumor-related biomarkers predictive of treatment efficacy.

Results: Of the 30 patients treated with ON-01, 13 (43.3%) were male, and the median age was 50.0 years (range, 22-75). A total of 36 grade 1, 12 grade 2, and 2 grade 3 adverse events were reported. Among all treated patients, the median OS was 12.0 months (95% CI, 10.1-13.9), median PFS was 3.0 months (95% CI, 1.7-4.3), and 2-year OS rate was 27.7% (95% CI, 12.6%-45.0%). Seven patients with recurrent multifocal gliomas demonstrated regression of non-injection site lesions following ON-01 therapy. Furthermore, patients with elevated expression of herpesvirus entry mediator exhibited significantly prolonged survival (p=0.015).

Conclusions: Intratumoral infusion of ON-01 appeared safe and demonstrated efficacy in patients with recurrent malignant glioma, with no evidence of neurotoxicity. The therapeutic response to ON-01 may be associated with HVEM expression levels.

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.