Functional role of wogonin in anti-angiogenesis

Am J Chin Med. 2012;40(2):415-27. doi: 10.1142/S0192415X12500322.

Abstract

Constitutive activation of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway occurs commonly in cancer cells and endothelial cells, and contributes to angiogenesis. Wogonin is a compound with many biologically relevant properties. We previously reported that wogonin blocked IL-6-induced angiogenesis through suppression of VEGF expression, an important regulator of angiogenesis. However, the pathway involved in the suppressive effect of wogonin on IL-6-induced VEGF has not been completely clarified. This study aimed to investigate the molecular mechanisms participating in the suppression of wogonin on IL-6-induced VEGF in vitro, focusing on IL-6R/JAK1/STAT3/VEGF pathway. Both STAT3 siRNA and wogonin treatment resulted in an abolition of the expression of VEGF. Moreover, our data revealed that wogonin treatment after STAT3 knock-down did not further suppress VEGF expression. The addition of IL-6R siRNA or wogonin resulted in a decrease in the expression level of the phosphorylated JAK1 protein. Furthermore, wogonin significantly decreased the amount of phosphorylated STAT3. Finally, by EMSA, wogonin suppressed IL-6-induced STAT3 binding activity in a concentration-dependent manner. Taken together, our results show that wogonin suppresses IL-6-induced VEGF by modulating the IL-6R/JAK1/STAT3 signaling pathway. Based on this study, we suggest that wogonin may provide a new potential therapeutic option for treatment of IL-6-related pathological angiogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Angiogenesis Inhibitors / pharmacology*
  • Down-Regulation / drug effects
  • Drugs, Chinese Herbal / pharmacology*
  • Flavanones / pharmacology*
  • Human Umbilical Vein Endothelial Cells / drug effects
  • Human Umbilical Vein Endothelial Cells / metabolism
  • Humans
  • Interleukin-6 / adverse effects
  • Interleukin-6 / metabolism
  • Janus Kinase 1 / genetics
  • Janus Kinase 1 / metabolism
  • Neovascularization, Pathologic / drug therapy
  • Neovascularization, Pathologic / enzymology
  • Neovascularization, Pathologic / genetics
  • Neovascularization, Pathologic / metabolism*
  • STAT3 Transcription Factor / genetics
  • STAT3 Transcription Factor / metabolism
  • Signal Transduction / drug effects
  • Vascular Endothelial Growth Factor A / genetics
  • Vascular Endothelial Growth Factor A / metabolism

Substances

  • Angiogenesis Inhibitors
  • Drugs, Chinese Herbal
  • Flavanones
  • Interleukin-6
  • STAT3 Transcription Factor
  • Vascular Endothelial Growth Factor A
  • Janus Kinase 1
  • wogonin