The Role of Exosomes in Cancer Progression

Abstract

Early detection, characterization and monitoring of cancer are possible by using extracellular vesicles (EVs) isolated from non-invasively obtained liquid biopsy samples. They play a role in intercellular communication contributing to cell growth, differentiation and survival, thereby affecting the formation of tumor microenvironments and causing metastases. EVs were discovered more than seventy years ago. They have been tested recently as tools of drug delivery to treat cancer. Here we give a brief review on extracellular vesicles, exosomes, microvesicles and apoptotic bodies. Exosomes play an important role by carrying extracellular nucleic acids (DNA, RNA) in cell-to-cell communication causing tumor and metastasis development. We discuss the role of extracellular vesicles in the pathogenesis of cancer and their practical application in the early diagnosis, follow up, and next-generation treatment of cancer patients.

Keywords: biomarkers; cancer; cell-free nucleic acids; exosomes; liquid biopsy.

Figure 1

Exosome biogenesis. The process of endocytosis results in the formation of an early endosome, followed by a maturation to a late endosome that may bidirectionally exchange vesicles with the Golgi apparatus and the endoplasmic reticulum. Invagination of late endosomal membranes forms the intraluminal vesicles (ILVs) contained in the multivesicular body (MVB). The MVB may fuse with the plasma membrane and release ILVs to the extracellular space as exosomes. On the other hand, the MVB may also be transported to a lysosome for subsequent degradation of its content.