Fig. 3

Roles of NADPH oxidase (NOX)-derived reactive oxygen species (ROS) in regulating angiogenesis. Hypoxia induces vascular endothelial growth factor (VEGF) production from tumor cells which stimulates NOXs to produce ROS, thereby inducing downstream redox signaling events including expressions of various redox-sensitive transcriptional factors (hypoxia-inducible factor (HIF)-1, redox factor (Ref)-1, nuclear factor (NF)-κB, and activator protein (AP)-1) and genes (VEGF, matrix metalloproteinases (MMPs), cyclooxygenase (COX)-2, and urokinase plasminogen activator (uPA)), which are involved in angiogenesis. ECs, endothelial cells