163855 20251107115329.0 doi 10.1007/s11060-025-05253-0 sideral 145938 ART-2025-145938 eng Baselga, Marta (orcid)0000-0003-2672-5790 Three-dimensional ultrastructural analysis of glioblastoma reveals spheresome-mediated intercellular communication 2025 Purpose: The tumor microenvironment plays a central role in glioblastoma progression and treatment resistance, with extracellular vesicles (EVs) mediating much of the intercellular communication. Here, we provide the first ultrastructural evidence of spheresomes -a specific EV subtype- predominance in human glioblastomas, together with novel observations on their transport and interactions. Methods: Tumor samples from four patients with histologically confirmed glioblastoma were examined using transmission electron microscopy (TEM) and three-dimensional (3D) reconstructions from ultrathin serial sections. Results: In glioblastomas, spheresomes, contained within multivesicular spheres (MVSs), were the most prevalent EV subtype, exceeding multivesicular bodies containing exosomes in number and size. 3D reconstructions revealed numerous contacts between glioblastoma tumor cells and MVSs, active release events, and occasional traversal of endothelial cells into the vascular lumen, suggesting potential for both local and systemic transport. Additionally, we report independent and descriptive new ultrastructural observations of glioblastoma. These tumors well-differenciated cells exhibited irregular nuclei with nuclear blebs and nuclear envelope-limited chromatin sheets, as well as cytoplasmic concentric rough endoplasmic reticulum laminations, membranous stacks, crystalline bodies, and concentric rearrangements of gliofilaments. Primary cilia (9 + 0) were also observed. Conclusions: These findings expand the ultrastructural profile of glioblastoma, highlight spheresomes as a potentially important EV population in tumor communication, and underscore the value of further molecular studies to evaluate their role as potential biomarkers. info:eu-repo/grantAgreement/ES/DGA/PROY_B21_24 info:eu-repo/semantics/closedAccess All rights reserved http://www.europeana.eu/rights/rr-f/ info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Berna, Sophia Medina Pérez, Víctor Manuel Soriano, Mario Giraldo, Cindy Muñoz, Guillermo Universidad de Zaragoza (orcid)0000-0001-8567-4327 Calatayud-Pérez, Juan Universidad de Zaragoza (orcid)0000-0003-3883-3094 Aguas, Jesús Universidad de Zaragoza (orcid)0000-0001-5821-3920 Schuhmacher, Alberto J. Junquera, Concepción (orcid)0000-0002-9951-1075 1013 090 Universidad de Zaragoza Dpto. Cirugía Área Cirugía 1013 020 Universidad de Zaragoza Dpto. Cirugía Área Anatomía Patológica 176, 1 (2025), [11 pp.] J. neuro-oncol. JOURNAL OF NEURO-ONCOLOGY 0167-594X 7940163 http://zaguan.unizar.es/record/163855/files/texto_completo.pdf Versión publicada 2398013 http://zaguan.unizar.es/record/163855/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:163855 articulos driver 2025-11-07-10:26:03 ARTICLE