Differential inhibition of endothelial cell proliferation and migration by urokinase subdomains: amino-terminal fragment and kringle domain.
The serine protease urokinase-type plasminogen activator (uPA) is implicated in pericellular proteolysis in a variety of physiological and pathological processes including angiogenesis and tumor metastasis. The kringle domain of uPA (UK1) has proven to be an anti-angiogenic molecule with unknown mechanism and amino terminal fragment of uPA (u-ATF) with additional growth factor-like domain can be used for blocking interaction of uPA and uPA receptor. Here, we compared anti-angiogenic activities of these two molecules in vitro and in vivo. The recombinant u-ATF from E. coli and refolded in vitro was found to bind to uPAR with high affinity, whereas E. coli-derived UK1 showed no binding by Biacore analysis. In contrast to UK1 having potent inhibitory effect, u-ATF exhibited low inhibitory effect on bovine capillary endothelial cell growth (ED(50)>320 nM). Furthermore, u-ATF inhibition of VEGF-induced migration of human umbilical vein endothelial cell was far less sensitive (IC(50) = 600 nM) than those observed with UK1, and angiogenesis inhibition was marginal in chorioallantoic membrane. These results suggest that kringle domain alone is sufficient for potent anti- angiogenic activity and additional growth factor-like domain diverts this molecule in undergoing different mechanism such as inhibition of uPA/uPAR interaction rather than undergoing distinct anti- angiogenic mechanism driven by kringle domain.
Kim
Kwang Sei
KS
Cancer Research Institute, Catholic Research Institute of Medicial Sciences, The Catholic University of Korea, Seoul 137-701, Korea.
Hong
Yong-Kil
YK
Lee
Yoon
Y
Shin
Joo-Young
JY
Chang
Soo-Ik
SI
Chung
Soo Il
SI
Joe
Young  Ae
Y
D000818:Animals; D015374:Biosensing Techniques; D002417:Cattle; D002455:Cell Division / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D002645:Chickens; D006224:Cricetinae; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects*; D006801:Humans; D007700:Kinetics; D018082:Kringles; D008024:Ligands; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator / Q000737:chemistry* / Q000235:genetics / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology
D008024:Ligands; C524898:PLAUR protein, human; D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D042461:Vascular Endothelial Growth Factor A; D014568:Urokinase-Type Plasminogen Activator