Induction of endothelial proliferation and angiogenesis through activating the ERK1/2/EGF pathway mediate by CXC chemokine receptor 2 by chemokine (C-X-C motif) ligand 1.

Abstract

138 Background: Endothelial cell growth and proliferation are critical for tumoral angiogenesis. We report here that blockade of Chemokine (C-X-C motif) ligand 1 (CXCL1) results in reduction of human endothelial cell proliferation and its ability to induce angiogenesis. Methods: Two human endothelial cell lines, HUVEC and HDMEC, were used in the in vitro assays. Proliferation assay and matrigel tube formation assay were performed to test the inhibitory effect of anti-CXCL antibody on the activity of endothelial cells in vitro. Matrigel plug assay in nude mice was performed to test the in vivo angiogenic activity of CXCL1. Results: CXCL1 interacts with its receptor CXC chemokine Receptor 2 and induces endothelial cell proliferation, whereas blockade of CXCL1 is associated with reduction in cellular proliferation through a decrease in levels of cyclin D and cdk4 and inhibition of angiogenesis through EGF and ERK 1/2. Targeting CXCL1 inhibits neoangiogenesis but has no effect on disrupting established vasculature. Furthermore targeting CXCL1 is associated with reduction in migration of human endothelial cells in an in vitro model. Additionally, neutralizing antibody against CXCL1 in a xenograft angiogenesis model resulted in inhibition of angiogenesis. Conclusions: CXCL1-induced regulation of angiogenesis has not been studied extensively in human cancers, thus these findings illustrate a novel contribution of CXCL1 interactions in pathological angiogenesis. Therefore, the ability to selectively modulate CXCL1, specifically in tumoral angiogenesis, may promote the development of novel oncologic therapeutic strategies.