title: TR-644 a novel potent tubulin binding agent induces impairment of endothelial cells function and inhibits angiogenesis.
abstract: TR-644 is a novel combretastatin A-4 (CA-4) analogue endowed with potent microtubule depolymerizing activity superior to that of the lead compound and it also has high affinity to colchicines binding site of tubulin. We tested TR-644 anti-angiogenic effects in human umbilical endothelial cells (HUVEC). It showed no significant effects on the growth of HUVEC cells at concentrations below 1,000 nM, but at much lower concentrations (10-100 nM) it induced inhibition of capillary tube formation, inhibition of endothelial cell migration and affected endothelial cell morphology as demonstrated by the disruption of the microtubule network. TR-644 also increased permeability of HUVEC cells in a time dependent manner. The molecular mechanism for the anti-vascular activity of TR-644 was investigated in detail. TR-644 caused G2/M arrest in endothelial cells and this effect correlated with downregulation of the expression of Cdc25C and Cdc2(Tyr15). Moreover TR-644 inhibited VEGF-induced phosphorylation of VE-cadherin but did not prevent the VEGF-induced phosphorylation of FAK. In chick chorioallantoic membrane in vivo assay, TR-644 (0.1-1.0 pmol/egg) efficiently counteracted the strong angiogenic response induced by FGF. Also CA-4, used as reference compound, caused an antagonistic effect, but in contrast, it induced per se, a remarkable angiogenic response probably due to an inflammatory reaction in the site of treatment. In a mice allogenic tumor model, immunohistochemical staining of tumors with anti-CD31 antibody showed that TR-644 significantly reduced the number of vessel, after 24 h from the administration of a single dose (30 mg/Kg).
authors: Laboratorio di Oncoematologia, Dipartimento di Salute della Donna e del Bambino, Università di Padova, Via Giustiniani 3, 35128 Padua, Italy.
authors: Elena
authors: E
authors: Porcù
authors: Giampietro
authors: G
authors: Viola
authors: Roberta
authors: R
authors: Bortolozzi
authors: Luca
authors: L
authors: Persano
authors: Stefania
authors: S
authors: Mitola
authors: Roberto
authors: R
authors: Ronca
authors: Marco
authors: M
authors: Presta
authors: Romeo
authors: R
authors: Romagnoli
authors: Pier Giovanni
authors: PG
authors: Baraldi
authors: Giuseppe
authors: G
authors: Basso
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D016203:CDC2 Protein Kinase; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D002642:Chick Embryo; D003114:Colony-Forming Units Assay; D019926:Cyclin B / Q000378:metabolism; D018844:Cyclin-Dependent Kinases; D042783:Endothelial Cells / Q000187:drug effects*; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D007150:Immunohistochemistry; D008869:Microtubule-Associated Proteins / Q000494:pharmacology*; D015394:Molecular Structure; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010766:Phosphorylation / Q000187:drug effects; D013844:Thiazoles / Q000737:chemistry / Q000494:pharmacology*; D020687:cdc25 Phosphatases / Q000378:metabolism
chemical_list: D020533:Angiogenesis Inhibitors; D019926:Cyclin B; D008869:Microtubule-Associated Proteins; C584136:TR-644; D013844:Thiazoles; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; D016203:CDC2 Protein Kinase; C528899:CDK1 protein, human; D018844:Cyclin-Dependent Kinases; C517009:CDC25C protein, human; D020687:cdc25 Phosphatases