Extracellular vesicles: General features and usefulness in diagnosis and therapeutic management of colorectal cancer

Figure 4 Antitumor immune system balance modulation by colorectal cancer cells extracellular vesicles. Antitumor immune response is largely modulated by colorectal cancer (CRC) cells through either extracellular signaling molecules (cytokines, etc.) secretion or extracellular vesicles (EVs) production and release. CRC cells EVs contain inhibiting or activating molecules that favor target cells expansion, mobilization, and recruitment (regulatory T cells and mesenchymal stem cells), polarization and activation (tumor associated macrophages M2) and block others (CD8+ T-cells, dendritic cells, and natural killer cells). MSC: Mesenchymal stromal cells; CD4: CD4 positive T cells; CD8: CD8 positive T cells; EC: Endothelial cells; TC: Tumor cells; TAM: Tumor associated macrophages; NK: Natural killer cells; Treg: Regulatory T cells.