An Urokinase Receptor Antagonist That Inhibits Cell Migration By Blocking The Formyl Peptide Receptor.

Urokinase receptor (uPAR) plays a key role in physiological and pathological processes sustained by an altered cell migration. We have developed peptides carrying amino acid substitutions along the Ser(88)-Arg-Ser-Arg-Tyr(92) (SRSRY) uPAR chemotactic sequence. The peptide pyro glutamic acid (pGlu)-Arg-Glu-Arg-Tyr-NH2 (pERERY-NH2) shares the same binding site with SRSRY and competes with N-formyl-Met-Leu-Phe (fMLF) for binding to the G-protein-coupled N-formyl-peptide receptor (FPR). pERERY-NH2 is a dose-dependent inhibitor of both SRSRY- and fMLF-directed cell migration, and prevents agonist-induced FPR internalization and fMLF-dependent ERK1/2 pbosphorylation. pERERY-NH2 is a new and potent uPAR inhibitor which may suggest the generation of new pharmacological treatments for pathological conditions involving increased cell migration.