Proteome of human glioblastoma and meningioma tissue small extracellular vesicles

Small extracellular vesicles have gained attention in neuroscience due to their role in cell-to- cell communication and their potential diagnostic and therapeutic applications. Despite progress in the field, there remains a gap in our understanding of the composition and function of extracellular vesicles with regards to brain tumours. Previous studies have primarily evaluated extracellular vesicles obtained from patient fluids or cell culture medium, rather than directly from tumour tissue. Here we successfully isolated small extracellular vesicles from surgical tissue biopsies of glioblastomas or meningiomas, marking, marking the first report of in situ extracellular vesicle isolation from brain tumours. The protein content of the tumour tissue and their extracellular vesicles was characterized using tandem mass spectrometric proteomics, revealing proteins exclusively detected or enriched in extracellular vesicles relative to the tumour tissue. While our study confirmed proteins previously identified in glioblastoma and meningioma extracellular vesicles from various sources, it also identified novel proteins and pathways associated with extracellular vesicles from these tumour types. This study underscores the benefit of analysing in situ extracellular vesicles derived directly from brain tissue for insights into tumour biology and highlights the need for further research comparing extracellular vesicles from various types and grades of brain tumours. ### Competing Interest Statement The authors have declared no competing interest.