Inhibition of angiogenesis in vitro by αv integrin-directed antisense oligonucleotides

The integrin αvβ3 plays a central role in angiogenesis. In this study, we used antisense oligodeoxyribonucleotides (ONs) directed against the αv subunit of αvβ3 to inhibit integrin expression. Ten ON sequences, which were selected by systematic alignment of computer-predicted secondary structures of αv mRNA, were transfected into human umbilical vein endothelial cells (HUVECs). Following stimulation by PMA, five antisense ONs significantly inhibited αv mRNA and protein expression in activated HUVEC at a concentration of 0.05 μM with complete prevention of PMA-induced αv up-regulation by the most potent antisense ON. Inhibition of αv expression was associated with significant inhibition of migration of HUVEC by 28% and had no effect on proliferation and apoptosis. Moreover, transfection of antisense ON inhibited the formation of tube-like structures of HUVEC in Matrigel by 44%. In a cell culture model of angiogenesis consisting of a co-culture of endothelial cells with fibroblasts, transfection of antisense ONs resulted in an inhibition of tube formation of 61%. In conclusion, αv antisense ONs are potent inhibitors of angiogenesis in vitro. They might, therefore, be a therapeutic alternative to antagonists, which directly bind to αv integrins, and might be useful for the treatment of malignant tumors and hematological malignancies.