title: Identification of DW532 as a novel anti-tumor agent targeting both kinases and tubulin.
abstract: OBJECTIVE
  7,8-Dihydroxy-4-(3-hydroxy-4-methoxyphenyl)-2H-chromen-2-one (DW532) is one of simplified analogues of hematoxylin that has shown broad-spectrum inhibition on tyrosine kinases and in vitro anti-cancer activities. The aim of this study was to identify DW532 as a agent targeting both kinases and tubulin, and to investigate its anti-cancer and anti-angiogenesis activities.
  
  
  METHODS
  In vitro tyrosine kinases activity was examined with ELISA, and tyrosine kinases activity in cells was evaluated with Western blot analysis. Tubulin turbidity assay, surface plasmon resonance and immunofluorescence technique were used to characterize the tubulin inhibitory activity. Cell proliferation was examined with SRB assay, and cell apoptosis and cell cycle distribution were analyzed with Annexin-V/PI staining and flow cytometry. Tube formation, aortic ring and chick chorioallantoic membrane assays were used to evaluate the anti-angiogenesis efficacy.
  
  
  RESULTS
  DW532 inhibited EGFR and VEGFR2 in vitro kinase activity (the IC50 values were 4.9 and 5.5 μmol/L, respectively), and suppressed their downstream signaling. DW532 dose-dependently inhibited tubulin polymerization via direct binding to tubulin, thus disrupting the mitotic spindle assembly and leading to abnormal cell division. In a panel of human cancer cells, DW532 (1 and 10 μmol/L) induced G2/M phase arrest and cell apoptosis, which subsequently resulted in cytotoxicity. Knockdown of BubR1 or Mps1, the two core proteins of the spindle assembly checkpoint dramatically decreased DW532-induced cell cycle arrest in MDA-MB-468 cells. Moreover, treatment with DW532 potently and dose-dependently suppressed angiogenesis in vitro and in vivo.
  
  
  CONCLUSIONS
  DW532 is a dual inhibitor against tubulin and tyrosine kinases, and deserves further development as a novel anti-cancer agent.
authors.forename: Ting
authors.initials: T
authors.lastname: Peng
authors.forename: Jian-Rui
authors.initials: JR
authors.lastname: Wu
authors.forename: Lin-Jiang
authors.initials: LJ
authors.lastname: Tong
authors.forename: Meng-Yuan
authors.initials: MY
authors.lastname: Li
authors.forename: Fang
authors.initials: F
authors.lastname: Chen
authors.forename: Yi-Xin
authors.initials: YX
authors.lastname: Leng
authors.forename: Rong
authors.initials: R
authors.lastname: Qu
authors.forename: Kun
authors.initials: K
authors.lastname: Han
authors.forename: Yi
authors.initials: Y
authors.lastname: Su
authors.forename: Yi
authors.initials: Y
authors.lastname: Chen
authors.forename: Wen-Hu
authors.initials: WH
authors.lastname: Duan
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
authors.affiliation: 201203, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ding
mesh_terms: D020533:Angiogenesis Inhibitors / Q000737:chemistry / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000737:chemistry* / Q000494:pharmacology; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D045744:Cell Line, Tumor; D002867:Chromones / Q000737:chemistry* / Q000494:pharmacology; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D009369:Neoplasms / Q000098:blood supply / Q000188:drug therapy* / Q000378:metabolism; D047428:Protein Kinase Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D014404:Tubulin / Q000378:metabolism; D050257:Tubulin Modulators / Q000737:chemistry* / Q000494:pharmacology; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D020533:Angiogenesis Inhibitors; D000970:Antineoplastic Agents; D002867:Chromones; D047428:Protein Kinase Inhibitors; D014404:Tubulin; D050257:Tubulin Modulators; D066246:ErbB Receptors; C000588866:KDR protein, human; D040301:Vascular Endothelial Growth Factor Receptor-2