Apart from directly targeting VEGF, a handful of miRNAs regulate VEGF-dependent tumor angiogenesis by targeting VEGF inducers, such as HIF pathway (miR-22 , miR-107 , miR-519c , miR-145 ), PI3K/AKT pathway (miR-26a , miR-145 ), mTOR pathway (miR-18a , miR-128 , miR-145 , miR-218 ), IGF1R pathway (miR-126 , miR-181b , miR-148a , miR-152 ) and VEGF upstream transcription factors (STAT3: miR-874 , Bmi-1: miR-16 , E2F3: miR-34a , NF90: miR-590-5p ). Conversely, miRNAs targeting the suppressors of these VEGF inducers promoted tumor angiogenesis. Overexpression of miR-21 induced tumor angiogenesis by targeting PTEN, which in turn activated AKT and ERK signaling and finally enhanced HIF-1α and VEGF expression in prostate cancer cells . E-cadherin downregulation by miR-9 activated β-catenin signaling, in turn upregulating VEGF-A expression and promoting tumor angiogenesis .