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Sciot, R.

Publications and source records attributed to Sciot, R..

3 recordsLinked to original sources

Macrophage-instructed GSDME couples glioblastoma cell-state plasticity with inflammatory cell death

Glioblastoma (GBM) cell states reflect spatial microenvironmental interactions. Here, using COMET spatial proteomics and RNAscope across multiregional human GBM tissue, spanning tumor cores with pseudopalisading regions, infiltrative margins and peripheral regions, together with multiplex spatial profiling of 202 specimens from 33 patients with matched primary and recurrent tumors, we identify full-length gasdermin E (GSDME-FL) as a macrophage-instructed regulator of malignant cell plasticity. Integration with single-cell transcriptomics and functional perturbation shows that GSDME-high tumor cells localize to macrophage-rich perivascular niches and are associated with delayed recurrence and longer patient survival. Mechanistically, macrophage-derived S100A4 activates EGFR-Sp1 signaling to induce GSDME-FL in neighboring GBM cells. GSDME-FL restrains hypoxia-associated mesenchymal plasticity and shapes macrophage-induced tumor state transitions independently of caspase activation. During immunogenic cell death (ICD), cleaved GSDME promotes pre-lytic swelling, early ATP efflux, and the release of canonical ICD-associated cytokines and chemokines. NLRP3 signaling further supports ATP release and licenses macrophage phagocytosis of dying GBM cells, whereas NINJ1-dependent membrane rupture enables terminal HMGB1 release. Vaccination with ICD-treated glioma cells elicits tumor rejection in a prophylactic intracranial challenge model. Notably, co-expression of GSDME and NINJ1 in macrophage-rich perivascular niches provides a spatial correlate of pathway convergence in patient tumors. Thus, our findings define how a spatial macrophage niche induces GSDME-FL, thereby coupling malignant cell state plasticity to the inflammatory properties of GBM cell death.

cancer biology↗

Longitudinal tumor ecosystem mapping defines glioblastoma treatment trajectories

Glioblastoma remains an invariably recurring and lethal brain tumor shaped by complex interactions between malignant and microenvironmental cells. How these interactions evolve under first-line standard-of-care (SOC) therapy remains unclear. We performed spatial single-cell profiling of 671 paired newly diagnosed and recurrent glioblastoma samples from 96 patients to map tumor-ecosystem evolution and its clinical relevance. We delineated five distinct patient subgroups, each characterized by unique ecosystem trajectories that correlated with clinical outcome. Patients whose tumors transitioned into oligodendrocyte-progenitor-like niches with enhanced vascular integrity, oxygenation and an IL10/CCL/MHCII immunomodulatory environment experienced improved clinical prognosis. In contrast, progression towards hypoxic mesenchymal/astrocyte-like niches dominated by strong LGALS1/SPP1/TGF{beta} immunosuppression predicted poor outcome. Furthermore, a subgroup of early-relapsing patients on SOC therapy that was characterized by a depletion of an antigen-presenting myeloid-cell-rich niche, exhibited diminished responsiveness to second-line lomustine therapy. Overall, mapping evolutions in glioblastoma ecosystems offers a novel framework for prognostic stratification and therapeutic guidance.

cancer biology↗

Single-cell molecular profiling using ex vivo functional readouts fuels precision oncology in glioblastoma

BackgroundFunctional profiling of freshly isolated glioblastoma cells is being evaluated as a next-generation method for precision oncology. While promising, its success largely depends on the method to evaluate treatment activity which requires sufficient resolution and specificity. MethodsHere, we describe the precision oncology by single-cell profiling using ex vivo readouts of functionality (PROSPERO) assay to evaluate the intrinsic susceptibility of high- grade brain tumor cells to respond to therapy. Different from other assays, PROSPERO extends beyond life/death screening by rapidly evaluating acute molecular drug responses at single-cell resolution. ResultsThe PROSPERO assay was developed by correlating short-term single-cell molecular signatures using CyTOF to long-term cytotoxicity readouts in representative patient- derived glioblastoma cell cultures (n=14) that were exposed to radiotherapy and the small- molecule p53/MDM2 inhibitor AMG232. The predictive model was subsequently projected to evaluate drug activity in freshly resected GBM samples from patients (n=34). Here, PROSPERO revealed an overall limited capacity of tumor cells to respond to therapy, as reflected by the inability to induce key molecular markers upon ex vivo treatment exposure, while retaining proliferative capacity, insights that were validated in PDX models. This approach also allowed the investigation of cellular plasticity, which in PDCLs highlighted therapy-induced proneural-to-mesenchymal transitions, while in patients samples this was more heterogeneous. ConclusionPROSPERO provides a precise way to evaluate therapy efficacy by measuring molecular drug responses using specific biomarker changes in freshly resected brain tumor samples, in addition to providing key functional insights in cellular behavior, which may ultimately complement standard, clinical biomarker evaluations.

cancer biology↗