Development of anti-angiogenesis therapy targeting integrin

描述(申请人提供)：实体肿瘤不会在没有建立自身血液供应的情况下生长到直径3-4毫米以上。由于肿瘤血管生成的重要作用，抗血管生成、单一治疗或与其他治疗药物联合治疗是一种非常有前途的肿瘤治疗方法。已经取得了巨大的成功，例如FDA批准的抗血管生成药物阿瓦斯丁。然而，临床研究表明，到目前为止，抗血管生成药物对癌症患者生存的好处并不显著。此外，目前抗血管生成药物的研究主要集中在阻断血管内皮生长因子/血管内皮生长因子受体信号转导的策略上。许多针对血管内皮生长因子/血管内皮生长因子受体途径开发的药物往往会引起不必要的生物副作用。目前迫切需要通过靶向促进和抑制肿瘤血管生成的许多其他生物途径来开发抗血管生成药物。我们在一个新的位置通过整合素v？3开发了一类新的抗血管生成蛋白，由？v的I-结构域和？3的PSI结构域形成的大口袋。计算模拟表明，大鼠CD2和人CD2的结构域1在空间上与设计的位置非常吻合。在D1-CD2处引入突变以连接设计蛋白和整合素之间的几个关键接触，优化了设计蛋白与整合素的结合。所设计的蛋白在体外具有较强的诱导内皮细胞凋亡的活性，而对其他细胞无影响。对肿瘤裸鼠PC-3移植瘤的测试表明，设计的蛋白质强烈抑制了肿瘤的生长。平行分析表明，我们开发的蛋白质抗血管生成药物在抑制肿瘤生长方面明显比阿瓦斯丁有效。在这个拟议的研究项目中，我们提议进行实验，以进一步验证设计的蛋白质是否确实与设计的整合素在设计的位置相互作用，以及设计的蛋白质是否确实通过靶向整合素发挥其活性。我们将通过不同的人类癌症动物模型广泛测试所开发的蛋白质抗血管生成剂的有效性。我们还设计了实验，以测试我们开发的抗血管生成蛋白与其他抗癌药物联合治疗癌症是否具有巨大的潜力。为了促进未来潜在的临床应用，我们提议进行广泛的实验，以表征蛋白质制剂的毒性和生物分布。我们的研究将有助于开发一种新的、更有效的抗血管生成药物用于癌症治疗。

DESCRIPTION (provided by applicant): Solid tumors will not grow beyond 3 - 4 mm in diameter without building up their own blood supply. Due to the essential role of tumor angiogenesis, anti-angiogenesis, mono-therapy or in- combination with other therapeutic agents, represents a very promising approach for cancer treatments. Great successes have been achieved, such as Avastin, a FDA approved anti- angiogenesis drug. However, clinical studies revealed that the cancer patient survival benefits of antiangiogenic drugs have thus far been insignificant. In addition, most current studies in development of anti-angiogenesis agent have been mainly focused on strategies of blocking VEGF/VEGFR signaling. Many agents that are developed against the VEGF/VEGFR pathway often cause unwanted biologic side effects. There is urgent need to develop anti-angiogenesis agents by targeting many other biological pathways that are involved in both stimulation and inhibition of cancer angiogenesis. We have developed a new class of anti-angiogenesis proteins by integrin ¿v¿3 at a novel site, the large pocket formed by the I-domain of ¿v and the PSI domain of ¿3. Computational modeling demonstrated that the domain 1 of rat CD2 and human CD2 spatially fit into the designed site very well. Mutations introduced at the D1-CD2 to bridge several key contacts between designed protein and the integrins optimize the binding of the designed protein with integrin. The designed proteins exhibit strong in vitro activity in induction of apoptosis on endothelial HUVEC cells with no effects on other cells. Tests with tumor nude mice PC-3 xenografts show that the designed proteins strongly inhibit tumor growth. Parallel analyses suggested that our developed protein anti-angiogenesis agents are significantly more effective than Avastin in inhibiting tumor growth. In this proposed research project, we propose experiments to further verify whether the designed protein indeed interact with integrin at the designed site, and whether the designed protein indeed exert its activity by targeting the integrin. We will extensively test the effectiveness of the developed protein anti-angiogenesis agents by various animal models of human cancers. We also design experiments to test whether our developed anti-angiogenesis proteins will have great potency for cancer treatment in combination with other anti-cancer drugs. To facilitate potential future clinical applications, we propose experiments to extensively characterize toxicity and bio-distribution of the protein agents. Our study will lead to development of a new and more effective anti-angigenesis agent for cancer treatment.