Do exosomes play a pathogenic role in Epstein-Barr Virus (EBV)-associated cancers?

Exosomes are 40- to 100-nm membrane-bound small vesicles that carry a great variety of cellular cargoes including proteins, DNA, messenger RNAs (mRNAs), and microRNAs (miRNAs). These nanovesicles are detected in various biological fluids such as serum, urine, saliva, and seminal fluids. Exosomes serve as key mediators in intercellular communication by facilitating the transfer and exchange of cellular components from cells to cells. They contain various pathogenic factors whereby their adverse effects have been implicated in multiple viral infections and cancers. Interestingly, accumulating evidences showed that exosomes derived from tumour viruses or oncoviruses, exacerbate virus-associated cancers by remodelling the tumour microenvironment. Researchers from Sunway University summarize the contributing factors of Epstein-Barr virus (EBV) products-containing exosomes in viral pathogenesis and their potential implications in EBV-driven malignancies. Understanding the biological role of these exosomes in the disease would undoubtedly boost the development of a more comprehensive strategy to combat EBV-associated cancers and to better predict the therapeutic outcomes. Furthermore, the researchers also highlight the potentials and challenges of EBV products-containing exosomes being employed as diagnostic markers and therapeutic targets for EBV-related cancers.

Schematic diagram showing the EBV-related pathogenic factors that contributes
to cancer pathogenesis via exosomal pathway.

Internal vesicles or multivesicular bodies (MVBs) are formed by the inward budding of cellular compartments. The cargo is packaged into intraluminal vesicle (ILVs) within MVBs. The MVBs contain a wide range of pathogenic factors depending on the producer cell. The MVBs either fuse with lysosomes to degrade MVB contents or fuse with cell membrane to release exosomes. The exosomes enter the recipient cell via caveolae-mediated endocytosis and the pathogenic contents are implicated in the EBV-associated cancer pathogenesis.