Extracellular vesicle-mediated regulation of tumor angiogenesis- implications for anti-angiogenesis therapy.

Angiogenesis plays an important role in tumour progression. However, anti-angiogenesis therapy of inhibiting pro-angiogenic factors failed to meet expectations in certain types of tumour in clinical trials. Recent studies reveal that tumour-derived extracellular vesicles (EVs) are essential in tumour angiogenesis and anti-angiogenesis drug resistance. This function has most commonly been attributed to EV contents including proteins and non-coding RNAs. Here, we summarize the recent findings of tumour-derived EV contents associated with regulating angiogenesis and illustrate the underlying mechanisms. In addition, the roles of EVs in tumour microenvironmental cells are also illustrated with a focus on how EVs participate in cell-cell communication, contributing to tumour-mediated angiogenesis. It will help offer new perspectives on developing targets of anti-angiogenesis drugs and improve the efficacy of anti-angiogenesis therapies based on tumour-derived EVs.