Fig. 2
From: Extracellular vesicles in the tumor microenvironment: old stories, but new tales
Multiple roles of EV-delivered cargoes such as microRNAs (miRNAs) in altering the phenotypes of recipient cancer cells and shaping a pathologically active tumor microenvironment (TME). Cancer cells and stromal cells utilize EVs such as exosomes to influence surrounding cells within the microenvironmental niche by transferring bioactive molecules including miRNAs. Sorting miRNAs to EVs is regulated by cell activation-dependent changes in miRNA levels within donor cells. Specifically, miRNA-365, miRNA-106a/b, miRNA-222-3p and miRNA-221/222 are not only overexpressed in donor cells but also enriched in their exosomes, and upon exosome-mediated transmission these miRNAs can significantly enhance resistance of recipient cancer cells against anticancer agents [129,130,131,132,133]. In addition, other malignant properties including but not limited to proliferation capacity, angiogenesis capability, metastatic potential and immunosurveillance evasion are also subject to the impact of EVs released by stromal or cancer cells in the TME