MicroRNAs in tumor angiogenesis.

As it is necessary for tumor growth, angiogenesis has been an attractive target for drug therapy. Accumulating evidences indicate that microRNAs (miRNAs), which are short non-coding RNAs, delicately regulate the angiogenic signals through targeting angiogenic factors and protein kinases. They can modulate pro-angiogenic signals induced by vascular endothelial growth factor (VEGF) and anti-angiogenic signals induced by thrombospondin-1 (TSP-1), and therefore promote or inhibit tumor angiogenesis. Receptor tyrosine kinases (RTKs) and hypoxia inducible factor (HIF) are also targeted by miRNAs. Moreover, miRNAs crosstalk with reactive oxygen species (ROS) influencing tumor angiogenesis. It is critical to understand the role of miRNAs in tumor angiogenesis due to their therapeutic potential to improve outcome for cancer patients. The following review discusses the current state of knowledge related to tumor angiogenesis-regulatory miRNAs and their targets.