Alpha v integrin affinity/specificity and antiangiogenesis effect of a novel tetraaza cyclic peptide derivative, SU015, in various species.
The present study was undertaken to define the alpha v beta3 and alpha v beta5 binding potency and specificity of SU015, an integrin antagonist. SU015 inhibited alpha v beta3-mediated human umbilical vein endothelial cell or 293/beta3-transfected CHO cell adhesion to fibrinogen, with IC50 values of 0.21 +/- 0.11 muM and 0.32 +/- 0.02 microM. SU015 demonstrated comparable affinity to alpha v beta5 as compared with alpha v beta3 affinity, as well as a relatively high degree of specificity for human alpha v beta3- and alpha v beta5-mediated functions, as compared with other human integrins, including alphaIIbbeta3 (IC50 >100 microM), alpha5/beta1 (IC50 >100 microM), and alpha4/beta1 (IC50 >100 microM). SU015 demonstrated different degrees of species specificity in blocking alpha v beta3-mediated cellular adhesion, with relatively higher affinity to monkey (IC50 = 0.10 microM) and dog (IC50 = 1.30 microM) endothelial or smooth muscle cell alpha v beta3-mediated adhesion. Additionally, SU015 demonstrated a high degree of alpha v beta3 and alpha v beta5 specificity as compared with alpha4beta1-, alpha5beta1-, or alpha IIb beta3-mediated binding in the above species. In conclusion, SU015 is an alpha v beta3 and alpha v beta5 antagonist with relatively higher potency and specificity as compared with alpha IIb beta3, alpha5beta1, or alpha4beta1 integrins. Additionally, comparable alpha v beta3 and alpha v beta5 affinity for SU015 was demonstrated with human and monkey endothelial cells. These data also suggest that this bicyclic RGD analogue linked to a linker at the bottom leaves the RGD at the top available for binding and allows for conjugation with radioisotope for imaging and radiotherapy.
Mousa
Shaker A
SA
Pharmaceutical Research Institute, Albany College of Pharmacy, Albany, New York 12208, USA. mousas@acp.edu
D000818:Animals; D016466:CHO Cells; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism; D002460:Cell Line; D002642:Chick Embryo; D049033:Chorioallantoic Membrane; D006224:Cricetinae; D003412:Cricetulus; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects; D006801:Humans; D020128:Inhibitory Concentration 50; D039564:Integrin alphaV / Q000378:metabolism*; D016023:Integrins / Q000378:metabolism; D019169:Jurkat Cells; D008214:Lymphocytes / Q000187:drug effects; D051379:Mice; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D010456:Peptides, Cyclic / Q000494:pharmacology*; D011323:Primates; D013045:Species Specificity; D014471:Umbilical Veins / Q000166:cytology
D015815:Cell Adhesion Molecules; D039564:Integrin alphaV; D016023:Integrins; D010456:Peptides, Cyclic; C502838:SU015 compound