Isolation and characterization of exosomes and ectosomes

Extracellular vesicles (EVs) include the exosomes (30-100 nm) that are produced through the endocytic pathway via the multivesicular bodies and the ectosomes (100-1000 nm) that are released through the budding of the plasma membrane. Despite the differences in the mode of biogenesis and size, reliable markers that can distinguish between exosomes and ectosomes are non-existent. Moreover, the precise functional differences between exosomes and ectosomes remains poorly characterised. Here, using label-free quantitative proteomics, we highlight proteins that could be exploited as markers to discriminate between exosomes and ectosomes. For the first time, a global proteogenomics analysis unveiled the secretion of mutant proteins that are implicated in cancer progression through EVs. Follow up integrated bioinformatics and experimental approach highlighted that exosomes are more oncogenic than ectosomes. These findings ascertain that cancer cells facilitate oncogenesis by the secretion of mutant and oncoproteins into the tumor microenvironment via exosomes and ectosomes.

Learning Objectives:

• Learn how follow up integrated bioinformatics and experimental approach highlighted that exosomes are more oncogenic than ectosomes
• Learn how using label-free quantitative proteomics, proteins were highlighted that could be exploited as markers to discriminate between exosomes and ectosomes
• Learn how cancer cells facilitate oncogenesis by the secretion of mutant and oncoproteins into the tumor microenvironment via exosomes and ectosomes