Abstract: Tumor-derived exosomes (TEXs) are small membrane vesicles secreted by tumor cells. They contain various proteins and RNA which make they serve as functional mediators in cell interaction. TEXs can alter the components of extracellular matrix and induces epithelial-mesenchymal transition of tumor cells, which enhance the invasiveness of tumor cells. TEXs regulate immunity through multiple pathways, allowing circulating tumor cells to escape immune surveillance. TEXs promote premetastatic microenvironment in target organ before metastasis and induce angiogenesis after circulating tumor cells colonization. Understanding the role and mechanism of TEXs in this process can effectively block relevant signaling pathways which may provide new targeted therapies for clinic.

Key words: Neoplasm metastasis, Tumor escape, Neovascularization, pathologic, Tumor-derived exosomes, Neoplasm invasiveness