Angiogenesis is a key event in tumor growth and metastasis, chronic inflammatory disease, and cardiovascular disease. It is controlled by positive and negative regulators, which include vascular endothelial growth factor (VEGF) as the most active of these. VEGF/VEGF receptors are important targets not only for therapy but also for imaging. Based on the structural study of VEGF, we developed a novel cyclopeptide (cyclo-VEGI) that exhibits powerful antitumor properties. We herein report the design of novel molecules derived from cyclo-VEGI as potential targeting agents in cancer and other angiogenesis-related diseases. We performed selective chemical modification of the most active VEGF-derived cyclopeptide (cyclo-VEGI). Original hydrophilic linkers were synthesized and coupled to cyclo-VEGI. These reactions provide nanocarriers for delivery. The inhibitory effect of the different compounds on VEGF binding was evaluated in competition assays with 125I-VEGF. A fluorescent cyclo-VEGI peptide was synthezised to assess direct binding and internalization of cyclo-VEGI. Chemical modifications of cyclo-VEGI do not diminish the biological activity of cyclo-VEGI as measured in competition assays; in fact, it is even increased. Moreover there is a strong cellular accumulation of the fluorescent-labeled cyclo-VEGI. Conjugates synthesized in this study may be useful leads to design delivery systems for targeting approaches in cancer and other angiogenesis-related diseases. The modified cyclo-VEGIs may have a wide range of applications and represent a useful tool to develop delivery/carrier systems for therapeutic targeting or imaging.
血管生成是肿瘤生长和转移、慢性炎症疾病以及心血管疾病中的关键事件。它受到正负调节因子的控制,其中血管内皮生长因子(V
EGF)是最为活跃的分子之一。V
EGF/V
EGF受体不仅是治疗的重要靶点,也是成像的关键目标。基于对V
EGF结构的深入研究,我们开发出一种新型的环状肽(cyclo-V
EGI),展现出强大的抗癌性能。本文报道了从cyclo-V
EGI衍生的新型分子设计,旨在作为癌症和其他与血管生成相关疾病中的潜在靶向试剂。我们对源自V
EGF的最活跃的环肽(cyclo-V
EGI)进行了选择性的
化学修饰。合成了原有的亲
水性连接体并结合到cyclo-V
EGI上,这些反应为递送提供了纳米载体。通过与125I-V
EGF的竞争性试验,评估了不同化合物对V
EGF结合的抑制效果。制作了荧光标记的cyclo-V
EGI肽,以评估其直接结合及内化情况。
化学修饰后的cyclo-V
EGI并未降低其
生物活性,在竞争性试验中甚至有所增强。此外,荧光标记的cyclo-V
EGI在细胞内积累显著。本研究所合成的缀合物有望成为设计癌症和其他血管生成相关疾病靶向递送系统的有用先导。改良的cyclo-V
EGI具有广泛的潜在应用,并可能成为开发治疗靶向或成像递送/载体系统的有效工具。