Silencing of Eps8 inhibits in vitro angiogenesis

Aims: Eps8 is an actin-binding protein which has been proposed as a regulator of cancer cell motility and invasion. However, nothing much is known about its contribution to the invasive properties of endothelial cells (ECs), and more generally to angiogenesis. Main methods: Expression and silencing of Eps8 were evaluated by western blot analysis. The effect of Eps8 silencing on cell number and VEGF-induced signaling was tested with standard methods. Migration was evaluated by scratch wound assay and morphogenesis with 2-dimensional (2-D) tube formation and 3-dimensional (3-D) sprouting assays. Actin cytoskeleton was visualized by immunofluorescence. Key findings: We found that silencing of Eps8 profoundly affected the ability of human ECs to migrate and to undergo tube formation and sprouting in 2-D and 3-D in vitro assays, respectively. Notably, capillary-like outgrowth was strictly depending on Eps8 expression also in human tumor-derived ECs. Significance: Our data demonstrate for the first time the involvement of Eps8 in the morphological processes required for in vitro angiogenesis, and suggest that this protein might represent a common target for the design of new anticancer drugs, acting at the same time on both tumor and endothelial cells.