ANTI-ANGIOGENIC PEPTIDES DERIVED FROM HUMAN KININOGEN

一个新兴的范式是血浆或细胞外蛋白的片段可能调节血管生成。一种已知的血浆蛋白最近被确定为只有在蛋白水解激活后才具有抗血管生成活性。该蛋白与先前鉴定的具有抗血管生成活性的蛋白（如血管抑制素、血栓反应蛋白）没有同源性。这种活化蛋白与内皮细胞的特异性结合已被证实。这导致内皮细胞增殖在体外（IC50 = 10 nM）的抑制，以及在体内血管生成的基质塞模型。该活化蛋白也能抑制内皮细胞的迁移，IC50 = 100 nM。基于该蛋白序列的多肽已被合成和测试，并鉴定出对内皮细胞具有抗增殖活性的16聚肽。本I期计划的目标是确定抑制内皮细胞增殖和迁移所需的最小序列，并从活性和稳定性的角度优化这些肽。基于结构的药物设计将在II期使用，以优化的肽序列为基础开发拟肽。II期的目标是基于i期优化的肽序列，鉴定一种候选肽或拟肽。拟商业应用：病理性血管生成已涉及几种主要的人类疾病状态，包括癌症、关节炎、动脉粥样硬化和视网膜病变。我们建议创造一种候选药物，它可以特异性地抑制内皮细胞的增殖，并可以作为抗血管生成剂在临床上使用。血管生成的靶向治疗已经在体内得到了验证，可能在急性和慢性使用环境中都有应用。

An emerging paradigm is that fragments of plasma or extracellular proteins may regulate angiogenesis. A known plasma protein has recently been identified as having anti-angiogenic activity only after proteolytic activation. This protein has no homology to previously identified proteins with anti-angiogenic activity e.g. angiostatin, thrombospondin. The specific binding of this activated protein to endothelial cells has been demonstrated. This results in the inhibition of endothelial cell proliferation in vitro (IC50 = 10 nM) as well as angiogenesis in vivo in a Matrigel Plug model. The migration of endothelial cells is also inhibited by this activated protein with an IC50 = 100 nM. Peptides based on the sequence of this protein have been synthesized and tested and l6-mer peptides with anti- proliferative activity against endothelial cells have been identified. The goal of this Phase I proposal is to identify the minimal sequences required for the inhibition of endothelial cell proliferation and migration and to optimize these peptides from the standpoint of activity and stability. Structure-based drug design will be used in Phase II to develop peptidomimetics based on the optimized peptide sequences. The goal of Phase II will be to identify a drug candidate peptide or peptidomimetic based on the sequence(s) of the optimized peptides identified in Phase I. PROPOSED COMMERCIAL APPLICATIONS: Pathological angiogenesis has been implicated in several major human disease states including cancer, arthritis, atherosclerosis and retinopathy. We propose to create a drug candidate which would specifically inhibit the proliferation of endothelial cells and could be usefii1 clinically as an anti- angiogenic agent. The therapeutic targeting of angiogenesis has been validated in vivo and may have application in both the acute and chronic use setting.