Development of Novel VEGF Analogs

新型 VEGF 类似物的开发

• 批准号: 6992234
• 负责人: MARIUSZ W SZKUDLINSKI
• 金额: $ 10.8万
• 依托单位: TROPHOGEN, INC.
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-15 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6992234
• 关键词: biological signal transduction; biotechnology; drug design /synthesis /production; gene mutation; genetic manipulation; hormone analog; laboratory rat; protein engineering; protein structure; protein structure function; receptor binding; vascular endothelial growth factors

DESCRIPTION (provided by applicant): Our previous structure-function studies resulted in the development of the first analogs of glycoprotein hormones with major increases in receptor binding and bioactivity ("super-active analogs"). The majority of cancers are highly dependent on vascular endothelial growth factor A (VEGF-A) interaction with its KDR (kinase domain receptor) receptor to support tumor angiogenesis. Complete inhibition of synthesis and action of all the multiple forms of VEGF is difficult to achieve, and the use of more general receptor antagonists appears vital as an adjunct in any anti-angiogenic therapy. Previous attempts to develop high affinity VEGF agonists and antagonists were not successful, but we have developed several novel high affinity analogs of glycoprotein hormones that are structurally related to VEGF. We hypothesize that our novel approach of growth factor modifications would be entirely applicable to VEGF. New VEGF analogs will consist of linked monomers of VEGF with two types of modifications within the same molecule. First, "gain-of-function" amino acid substitutions will be introduced to enhance binding to the KDR receptor at one pole of the VEGF dimer (Site 1). We will apply charge scanning mutagenesis of amino acid residues within the peripheral loops of VEGF (Site 1) as well as other rational design methods previously proven successful for glycoprotein hormones. Our preliminary data indicate that it is possible to increase binding affinity of VEGF to the KDR receptor up to ten fold. This could be enhanced considerably in future studies by determining optimal combinations of selected amino acid substitutions. The second type of modifications will include "loss-of-function" mutations with or without mutations introducing additional glycosylation site or pegylation at the second pole of VEGF dimer (Site 2). Such an asymmetrical VEGF molecule with enhanced KDR receptor binding at one pole and elimination of binding at the second pole is expected not only to antagonize the action of VEGF but also to limit the pool of monomeric KDR receptors capable of heterodimerizing with other related receptors. In vitro receptor binding assays and bioactivity studies with human endothelial cells will be used to characterize these novel agonists and antagonists. In the subsequent Phase II studies we will assess the therapeutic potential of VEGF analogs using animal models of angiogenesis and tumorigenesis.

描述（由申请人提供）：我们之前的结构功能研究导致了第一个糖蛋白激素类似物的开发，其受体结合和生物活性显着增加（“超活性类似物”）。大多数癌症高度依赖血管内皮生长因子 A (VEGF-A) 与其 KDR（激酶结构域受体）受体的相互作用来支持肿瘤血管生成。完全抑制所有多种形式的 VEGF 的合成和作用是很难实现的，并且使用更通用的受体拮抗剂作为任何抗血管生成治疗的辅助剂似乎至关重要。之前开发高亲和力 VEGF 激动剂和拮抗剂的尝试并未成功，但我们开发了几种新型高亲和力糖蛋白激素类似物，其结构与 VEGF 相关。我们假设我们的生长因子修饰新方法将完全适用于 VEGF。新的 VEGF 类似物将由连接的 VEGF 单体组成，并在同一分子内进行两种类型的修饰。首先，将引入“功能获得”氨基酸取代，以增强 VEGF 二聚体一极（位点 1）与 KDR 受体的结合。我们将应用 VEGF（位点 1）外周环内氨基酸残基的电荷扫描诱变，以及先前已证明对糖蛋白激素成功的其他合理设计方法。我们的初步数据表明，可以将 VEGF 与 KDR 受体的结合亲和力提高十倍。通过确定所选氨基酸取代的最佳组合，可以在未来的研究中大大增强这一点。第二种类型的修饰将包括“功能丧失”突变，无论是否有在 VEGF 二聚体第二极（位点 2）引入额外糖基化位点或聚乙二醇化的突变。这种在一极增强 KDR 受体结合并消除第二极结合的不对称 VEGF 分子预计不仅会拮抗 VEGF 的作用，还会限制能够与其他相关受体异二聚化的单体 KDR 受体库。体外受体结合测定和人内皮细胞生物活性研究将用于表征这些新型激动剂和拮抗剂。在随后的 II 期研究中，我们将使用血管生成和肿瘤发生的动物模型评估 VEGF 类似物的治疗潜力。