Synthesis and Biological Evaluation of a c(RGDyK) Peptide Conjugate of SRPIN803

[Image: see text] In the present study, SRPIN803 and c(RGDyK)-SRPIN803 hybrid compounds were efficiently synthesized and evaluated for their stability in human plasma and buffers of pH 7.4 and 5.2. The hybrids were mainly cytostatic against a panel of tested cancer cells, whereas one c(RGDyK)-SRPIN803 hybrid, geo35, was the most active compound in this screen and was cytotoxic against cell lines MCF7 and MRC5 with IC(50) values of 61 and 63 μM, respectively. SRPIN803 and geo35 exhibited antiangiogenic activity in zebrafish embryos, and this effect was dose-dependent. Although c(RGDyK)-SRPIN803 hybrid compounds were found less potent compared to SRPIN803, they have shown activities interesting enough to illustrate the potential of this approach for the development of a new class of antiangiogenic compounds.