Ethoxyfagaronine, a synthetic analogue of fagaronine that inhibits vascular endothelial growth factor-1, as a new anti-angiogeneic agent

Invest New Drugs (2015) 33:7585 DOI 10.1007/s10637-014-0184-4

PRECLINICAL STUDIES

Ethoxyfagaronine, a synthetic analogue of fagaronine that inhibits vascular endothelial growth factor-1, as a new anti-angiogeneic agent

Farid Ouchani & Albin Jeanne & Jessica Thevenard & Jean-Jacques Helesbeux &

Amandine Wahart & Isabelle Letinois & Olivier Duval & Laurent Martiny &

Emmanuelle Charpentier & Jrme Devy

Received: 18 July 2014 /Accepted: 4 November 2014 /Published online: 19 November 2014 # Springer Science+Business Media New York 2014

Summary Angiogenesis plays a pivotal role in tumorigenesis and also contributes to the pathogenesis of hematologic malignancies. A number of plant compounds have shown efficacy in preclinical and clinical studies and some of them possess an anti-angiogenic activity. Our present findings report anti-angiogenic activities of ethoxyfagaronine (etxfag), a synthetic derivative of fagaronine. Once determined the noncytotoxic concentration of etxfag, we showed that the drug inhibits VEGF-induced angiogenesis in a Matrigel plug assay and suppresses ex vivo sprouting from VEGF-treated aortic rings. Each feature leading to neovascularization was then investigated and results demonstrate that etxfag prevents VEGF-induced migration and tube formation in human umbilical vein endothelial cells (HUVEC). Moreover, etxfag also suppresses VEGF-induced VEGFR-2 phosphorylation and inhibits FAK phosphorylation at Y-861 as well as focal adhesion complex turnover. Beside these effects, etxfag modifies MT1-MMP localization at the endothelial cell membrane. Finally, immunoprecipitation assay revealed that etxfag decreases VEGF binding to VEGFR-2. As we previously reported that etxfag is able to prevent leukemic cell invasiveness and adhesion to fibronectin, all together our data collectively support the anti-angiogenic activities of etxfag which could

represent an additional approach to current anti-cancer therapies.

Keywords Ethoxyfagaronine . Angiogenesis . VEGF receptor . FAK . MT1-MMP

Introduction

Angiogenesis is tightly regulated by competing influences between pro- and anti-angiogenic factors that have autocrine and paracrine effects on endothelial cells, pericytes, immune and hematopoietic cells. When derailed during tumorigenesis, this balance leads to abnormal and excessive angiogenesis. Among all angiogenic factors, vascular endothelial growth factor (VEGF) is the most potent inducer acting both on angiogenesis and vessel maintenance. VEGF binds to one of the three receptor tyrosine kinases (RTK), VEGFR-1, R-2 and R-3 and the VEGF/VEGFR-2 pathway appears to be the major pro-angiogenic transducer [1, 2].

Angiogenesis also takes part in the pathogenesis of hematologic malignancies and leukemia angiogenesis...