Paradoxical effects of ethoxidine, a topoisomerase I inhibitor, in the cellular processes leading to angiogenesis on endothelial cells.
Angiogenesis, a critical step in tumorigenesis, is defined by different processes leading to neovascularization. Topoisomerase I (Top I) is the target for some of the most successful anticancer drugs that decrease tumor cell proliferation. Ethoxidine, a benzo[c]phenanthridines derivative, camptothecin analogue, has been identified as a potent inhibitor of Top I in various cancer cell lines. This study was aimed to investigate the impact of ethoxidine on angiogenesis and cellular processes including migration, proliferation and adhesion since these processes play an important role in tumor progression. Ethoxidine was incubated for 24 h at low (10⁻⁹ M) and high (10⁻⁵ M) concentrations on two types of human endothelial cells: EaHy.926 and human umbilical endothelial cells. Vascular endothelial growth factor (VEGF, 20 ng/ml) was used as a positive control. Ethoxidine at low concentration increased cell proliferation and migration that was associated with enhanced metalloproteinase 2 expression and activity, whereas high concentration of ethoxidine inhibited all of these effects. The two concentrations of ethoxidine did not affect endothelial cell adhesion. Low concentration of ethoxidine increased VEGF expression and endothelial nitric oxide (NO) synthase expression, NO and superoxide anion productions, whereas high concentration of ethoxidine did not induce any effect. Taken together, the present results highlight paradoxical effects of ethoxidine on angiogenesis depending on the concentration used. This study underscores that in addition to its anti-proliferative properties, ethoxidine may affect the generation of vascular network in tumorigenesis.
INSERM UMR U694, Mitochondries: régulations et pathologies, Université d'Angers, IBS-IRIS, 49100 Angers, France.
Nicolas
N
Clere
Sébastien
S
Faure
Jean-Jacques
JJ
Helesbeux
Olivier
O
Duval
Ramaroson
R
Andriantsitohaina
D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D002448:Cell Adhesion / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004578:Electron Spin Resonance Spectroscopy; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D018919:Neovascularization, Physiologic; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000235:genetics / Q000378:metabolism; D010617:Phenanthridines / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013481:Superoxides / Q000378:metabolism; D059004:Topoisomerase I Inhibitors / Q000494:pharmacology*; D014471:Umbilical Veins / Q000166:cytology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
D010617:Phenanthridines; D012333:RNA, Messenger; D059004:Topoisomerase I Inhibitors; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C404513:ethoxidine; D013481:Superoxides; D009569:Nitric Oxide; C496314:NOS3 protein, human; D052250:Nitric Oxide Synthase Type III