title: Farrerol inhibited angiogenesis through Akt/mTOR, Erk and Jak2/Stat3 signal pathway.
abstract: BACKGROUND
  Farrerol is one of traditional Chinese medicines, isolated from Rhododendron dauricum L. It has been reported that Farrerol exerts multiple biological activities. Angiogenesis is an important drug target for cancer and inflammation therapy, the effect of Farrerol on angiogenesis is unknown.
  
  
  OBJECTIVE
  We aimed to investigate whether Farrerol may have inhibitory effects against angiogenesis.
  
  
  METHODS
  Two kinds of endothelial cells, named human umbilical vein endothelia cell and human micro vessel endothelial cells, were used to examine the effect and mechanism of Farrerol on angiogenesis. MTT assay was used to detect cell proliferation, wound healing assay and boyden's chamber assay were used to examine cell migration, Matrigel was used as basement membrane substratum in tube formation assay, Annexin V-FITC/PI dual staining assay and trypan blue staining were used to detect cell apoptosis, mouse aortic rings assay was performed as ex vivo assay, the expression of proteins involved in angiogenesis was tested using western blot, the binding of Farrerol to Stat3 was monitored by docking assay, molecular dynamics simulations and MM-GBSA method.
  
  
  RESULTS
  Farrerol showed an inhibitory effect on proliferation, migration and tube formation of human umbilical vein endothelia cell and human micro vessel endothelial cells in a concentration-dependent manner. Farrerol induced cell cycle arrest and increased the apoptotic percentage of endothelial cells. Farrerol also suppressed the formation of new micro vessels from mouse aortic rings. Moreover, Farrerol reduced the phosphorylation levels of Erk, Akt, mTOR, Jak2 and Stat3 as well as protein expression of Bcl-2 and Bcl-xl. Docking assay, molecular dynamics simulations and MM-GBSA method showed that Farrerol bound to domain of Stat3, Ser613,Gln635, Glu638 and Thr714 are the main residues in Farrerol binding sites with the binding free energy -7.3 ∼ -9.0kcal/mol.
  
  
  CONCLUSIONS
  In this study, we demonstrated that Farrerol inhibited angiogenesis through down regulation of Akt/mTOR, Erk and Jak2/Stat3 signal pathway. The inhibitory effect of Farrerol on angiogenesis suggested that this compound may be helpful to the angiogenesis-related diseases treatment, such as cancer and inflammations.
authors.affiliation: The Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Kaifeng 475004, China. Electronic address: fjdwl@hotmail.com.
authors.forename: Fujun
authors.initials: F
authors.lastname: Dai
authors.affiliation: Joint Tomato Research Institute, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Gao
authors.affiliation: The Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Kaifeng 475004, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: The Key Laboratory of Natural Medicine and Immuno-Engineering, Henan University, Kaifeng 475004, China.
authors.forename: Chaojie
authors.initials: C
authors.lastname: Wang
authors.affiliation: Institute of Chemical Biology, Pharmaceutical College of Henan University, Kaifeng 475004, China. Electronic address: xiesq@henu.edu.cn.
authors.forename: Songqiang
authors.initials: S
authors.lastname: Xie
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects; D001485:Basement Membrane / Q000187:drug effects; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D002867:Chromones / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D053614:Janus Kinase 2 / Q000187:drug effects*; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D051379:Mice; D050796:STAT3 Transcription Factor / Q000187:drug effects*; D015398:Signal Transduction / Q000187:drug effects; D058570:TOR Serine-Threonine Kinases / Q000187:drug effects*; D014945:Wound Healing / Q000187:drug effects
chemical_list: D020533:Angiogenesis Inhibitors; D002867:Chromones; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C015881:farrerol; C546842:MTOR protein, human; C507924:JAK2 protein, human; D053614:Janus Kinase 2; D058570:TOR Serine-Threonine Kinases
keywords: Angiogenesis; Endothelial cells; Farrerol; Signal pathway