RT Journal Article SR Electronic T1 Interrelationship Between Protein Phosphatase 1 and TGF-β in Regulating Motility and Cytoskeletal Architecture of Endothelial Cells JF Anticancer Research JO Anticancer Res FD International Institute of Anticancer Research SP 4861 OP 4866 VO 30 IS 12 A1 JARRETT E. WALSH A1 M. RITA I. YOUNG YR 2010 UL http://ar.iiarjournals.org/content/30/12/4861.abstract AB Motility of endothelial cells is a requirement for the vascularization of solid malignancies. While tumors have been shown to produce a host of angiogenic factors, including TGF-β, the mechanisms by which such factors regulate endothelial cell motility have not yet been defined. Thus, the role of the serine/threonine phosphatase PP-1 in regulating endothelial cell motility and cytoskeletal architecture was studied. The present study demonstrated that TGF-β stimulation of motility is dependent on PP-1. Likewise, TGF-β was shown to up-regulate paxillin expression through a process that was PP-1 dependent. The interplay between PP-1 and TGF-β was further observed by the induction of cell rounding and the loss of paxillin-actin co precipitations upon PP-1 inhibition and the compensation for these effects by TGF-β. Studies initiated to determine how PP-1 might regulate motility showed its role in maintaining cytoskeletal organization and its capacity to directly dephosphorylate the focal adhesion scaffolding protein paxillin. These studies suggest that the interplay between TGF-β and PP-1 regulates the motility of endothelial cells that is critical to the process of angiogenesis.