Figure 4.

Cancer-derived extracellular vesicles (EVs) in the primary tumor microenvironment mediate tumor evolution and progression. Exchange of EVs within the tumor facilitates phenotypic transfer between different subpopulations of cancer cells to spread metastatic traits during tumor evolution. EVs carrying extracellular matrix (ECM) proteins can serve as the “stepping stones” for directional cell movement to promote cancer cell invasion. EVs secreted by cancer cells also influence other cell types including endothelial cells, immune cells, and fibroblasts, leading to coevolution of the tumor microenvironment and tumor progression. The various types of cells in the tumor microenvironment also secrete EVs to influence cancer cell behaviors.