The Emerging Role of Exosomes in Cancer Progression and Their Potential as Therapy Targets

Exosomes are a specific population of extracellular vesicles (EVs) that originate from an endocytic process. Virtually every cell type secretes exosomes and their size ranges from 40 to 150 nm. Exosomes are surrounded by a lipid bilayer and contain functional cargo that comprises proteins, lipids and genetic material such as protein, RNA and DNA. In the recent years, several studies have reported the role of exosomes as mediators of intercellular communication. Exosomes serve as vehicles used by cancer cells and stromal cells to influence both local and distant metastatic sites, by reprogramming recipient cells. This chapter will focus on the mechanisms underlying the role of exosomes in tumor development, metastasis, immune escape, therapy resistance, microenvironment reprogramming and angiogenesis. Furthermore, we will also discuss the potential to target exosomes as a new therapeutic strategy in cancer.