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Recent studies have suggested that inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (statins) can play a role in protection against vascular risk, which is independent of cholesterol reduction. It could act by inhibiting the synthesis of isoprenoids (farnesylpyrophosphate (FPP) and geranylgeranylpyrophosphate (GGPP)), which are respectively essential for membrane attachment and biological activity of GTPases Ras and RhoA. This study demonstrates that a statin (cerivastatin) inhibits angiogenesis. This effect was due to a decrease in endothelial cell locomotion which was reversed by GGPP. It was mainly related to delocalization of RhoA from cell membrane to cytoplasm, responsible for the disorganization of actin stress fibers. Furthermore, a decrease in MMP-2 secretion, involved in cell invasion, was also observed. This effect is rather due to Ras inhibition as it was reversed by FPP. This anti-angiogenic activity could explain the beneficial effect of statins on atherosclerosis and on cancer prevention as shown by clinical studies.

The urokinase receptor (u-PAR), a protein anchored to cell membrane by a glycosyl phosphatidylinositol, plays a central role in cancer cell invasion and metastasis by binding urokinase plasminogen activator (u-PA), thereby facilitating plasminogen activation. Plasmin can promote cell migration either directly or by activating metalloproteinases that degrade some of the components of the extra cellular matrix. However, the IGR-OV1-Adria cell line contains the u-PAR but does not migrate even in the presence of exogenous u-PA, although the parental IGR-OV1 cell line migrates normally in the presence of u-PA. We therefore investigated the role of cell signalling for u-PA induced cell locomotion. We show that cell migration induced by u-PA-u-PAR complex is always associated with tyrosine kinase activation for the following reasons: (1) the blockade of the u-PAR by a chimeric molecule (albumin-ATF) inhibits not only the u-PA-induced cell migration, but also the signalling in IGR-OV1 line; (2) the binding of u-PA to u-PAR on non-migrating IGR-OV1-Adria cells was not associated with tyrosine kinase activation; (3) the inhibition of tyrosine kinase also blocked cell migration of IGR-OV1. Therefore tyrosine kinase activation seems to be essential for the u-PA-induced cell locomotion possibly by the formation of a complex u-PAR-u-PA with a protein whose transmembrane domain can ensure cell signalling. Thus, IGR-OV1 and IGR-OV1-Adria cell lines represent a good model for the analysis of the mechanism of u-PA-u-PAR-induced cell locomotion.