Development of a new microarray set-up for high through-put screening of exosome glycosylation

Abstract

Extracellular vesicles are membrane-enclosed vesicles released from cells, whose composition may change under different physiological and pathological conditions. They are involved in intercellular communication and regulation of cellular functions. An elevated concentration of extracellular vesicles in blood and altered composition can be a sign of a pathological state. Host cell-derived vesicles include apoptotic bodies, microvesicles, and exosomes, which vary in size, composition, and biosynthesis. Exosomes, the smallest vesicles (30-100 nm), contain host-derived proteins, carbohydrates, lipids, and nucleic acids. Numerous studies have examined the lipid, protein and RNA/DNA content of exosomes. However, very scarce information on their carbohydrate composition is available. Exosomes are expected to share glycosylation patterns with their parental cell, which could change in response to different pathologies. In particular, evidence for a correlation between surface glycosylation and properties of tumour cells, as e.g. tumour-immune escape, is emerging. Recently, a cell surface proteoglycan, glypican-1 (GPC1) has been identified as a potential non-invasive diagnostic and screening tool to detect early stages of pancreatic cancer, as it is specifically enriched on cancer cell-derived exosomes. Thus, isolation and characterization of exosomes in body fluids could enable the identification of specific markers that distinguish cancer exosomes from normal exosomes, aiding in the diagnosis and management of cancer.