Proteome of Glioblastoma-Derived Exosomes as a Source of Biomarkers

Abstract

Extracellular vesicles (EV) are involved in important processes of glioblastoma multiforme (GBM), including malignancy and invasion. EV secreted by glioblastoma cells may cross the hematoencephalic barrier and carry molecular cargo derived from the tumor into the peripheral circulation. Therefore, the determination of the molecular composition of exosomes released by glioblastoma cells seems to be a promising approach for the development of non-invasive methods of the detection of the specific exosomal protein markers in the peripheral blood. The present study aimed to determine the common exosomal proteins presented in preparations from different cell lines and search potential glioblastoma biomarkers in exosomes. We have performed proteomics analysis of exosomes obtained from the conditioned culture medium of five glioblastoma cell lines. A list of 133 proteins common for all these samples was generated. Based on the data obtained, virtual two-dimensional electrophoresis (2DE) maps of proteins presented in exosomes of glioblastoma cells were constructed and the gene ontology (GO) analysis of exosome proteins was performed. A correlation between overexpressed in glial cell proteins and their presence in exosomes have been found. Thus, the existence of many potential glioblastoma biomarkers in exosomes was confirmed.

Biomechanical Properties of Blood Plasma Extracellular Vesicles Revealed by Atomic Force Microscopy

“…The internal cavity of the exosome ( Figure 2 E) was deformed up to 4.06 nm (red color) and the slightly deformed rim (green) were resolved. The thickness of the rim was about 6 nm, which corresponded to the thickness of electronically dense lipid bi-layer well defined in Cryo-EM studies [ 15 , 31 ]. To the contrary, exomeres ( Figure 2 F) were slightly deformed at the center (~0.5–1.3 nm, green), but significant deformation comparable to their height (~3–4 nm, red) was observed at the periphery (commonly 1.5 ± 0.45 nm in width).…”

Delivery of functional exogenous proteins by plant-derived vesicles to human cells in vitro

“…In general, cryo-EM data are in accordance with the analysis of GF-EVs by other methods based on the single or the ensemble particle sizing approaches. Previously, several studies have reported that ultracentrifugation may cause aggregation or morphological changes of EVs 32 , 33 , including double and multilayer structures, which could be observed in substantial amounts in many exosome samples, prepared from human biological fluids or cell culture medium 34 – 36 . While GF-EVs were purified with more stringent centrifugation, Cryo-EM visualization did not show any significant nanovesicle aggregation or double particle formation in the obtained suspension.…”

Role of Extracellular Vesicles in Autoimmune Pathogenesis

“…EV morphology is also very diverse, with various exosomes observed within and on the surface of cells. These exosomes include various proteins, such as TSG101, ALIX, Integrin-1, CD9, CD63, CD81, and CD82 (13,14).…”