Imaging integrin alpha(v)beta(3) positive glioma with a novel RGD dimer probe and the impact of antiangiogenic agent (Endostar) on its tumor uptake

Integrin alpha(v)beta(3) has been recognized to play an important role in angiogenesis, tumor growth and metastasis. It will be of interest to apply this promising target for tumor imaging and visualization of tumor angiogenesis in vivo. In this study, a novel integrin alpha(v)beta(3) targetting imaging probe, Tc-99m-HYNIC-E[c(RGDfK)](2), was used to investigate the glioma uptake in vitro and in vivo before and after treatment with an antiangiogenic agent, endostar. The results indicated that U87MG glioma cells have high expression of integrin alpha(v)beta(3) and special uptake of Tc-99m-HYNIC-E[c(RGDfK)](2) both in cell line and in tumor xenograft. The endostatin analogue endostar can inhibit the expression of integrin alpha(v)beta(3) receptors in both U87MG cells in vitro and glioma tissues, which suggested that integrin pathway may play a role in antiangiogenic effect of Endostar. Tc-99m-HYNIC-E[c(RGDfK)](2) may be a promising molecular imaging probe for integrin alpha(v)beta(3) positive tumor imaging and open up the possibility to establish an molecular imaging modality for assessment of tomor antiangiogenic therapy. (c) 2013 Elsevier Ireland Ltd. All rights reserved.OncologySCI(E)4ARTICLE175-8033