The von Willebrand Factor stamps Plasmatic Extracellular Vesicles from Glioblastoma Patients

Abstract

Glioblastoma is a devastating tumor of the central nervous system characterized by a poor survival and an extremely dark prognosis, making its diagnosis, treatment and monitoring highly challenging. Numerous studies have highlighted extracellular vesicles (EVs) as key players of tumor growth, invasiveness and resistance, as they carry and disseminate oncogenic material in the local tumor microenvironment and at distance. However, whether their quality and quantity reflect individual health status and changes in homeostasis is still not fully elucidated. Here, we separated EVs from plasma collected at different time points alongside with the clinical management of GBM patients. Our findings confirm that plasmatic EVs could be separated and characterized with standardized protocols, thereby ensuring the reliability of measuring vesiclemia, i.e. extracellular vesicle concentration in plasma. This unveils that vesiclemia is a dynamic parameter, which could be reflecting tumor burden and/or response to treatments. Further label-free liquid chromatography tandem mass spectrometry unmasks the von Willebrand Factor (VWF) as a selective protein hallmark for GBM-patient EVs. Our data thus support the notion that EVs from GBM patients showed differential protein cargos that can be further surveyed in circulating EVs, together with vesiclemia.

Comparison of interferometric light microscopy with nanoparticle tracking analysis for the study of extracellular vesicles and bacteriophages

“…A recent study showed the Videodrop to correctly enumerate two lentiviral virions and a baculovirus, whereas it underestimated the absolute viral concentration of an adenovirus relative to classical titration procedures (Turkki et al., 2021). A Videodrop instrument was also used to estimate the concentration of EVs in plasma, but no control experiments to verify the performance of the device were done in this study (Sabbagh et al., 2021). The main characteristics of the Videodrop, ZetaView, and NanoSight instruments are summarized in Table 1.…”

Comparison of interferometric light microscopy with nanoparticle tracking analysis for the study of extracellular vesicles and bacteriophages

“…A recent study showed the Videodrop to correctly enumerate two lentiviral virions and a baculovirus, whereas it underestimated the absolute viral concentration of an adenovirus relative to classical titration procedures (Turkki et al 2021). A Videodrop instrument was also used to estimate the concentration of EVs in plasma, but no control experiments to verify the performance of the device were done in this study (Sabbagh et al 2021). The main characteristics of the Videodrop, ZetaView, and NanoSight instruments are summarized in Table 1.…”