Studies of the Antifungal Drug Itraconazole As A Novel Inhibitor of Angiogenesis

描述（由申请人提供）：在约翰霍普金斯药物库筛选内皮细胞增殖抑制剂时，抗真菌药物伊曲康唑被鉴定为 新的血管生成抑制剂。早期的研究揭示了伊曲康唑抗血管生成作用的几种重要细胞活性，包括抑制内皮细胞周期t G1和mTOR信号通路。伊曲康唑在体外和体内血管生成和肿瘤异种移植的各种动物模型中也显示出显著的抗血管生成活性。此外，伊曲康唑作为肺癌、前列腺癌和皮肤癌的新治疗方法已进入多项2期人体临床研究，并显示出显著的疗效。利用可点击的伊曲康唑光亲和探针，鉴定了伊曲康唑的主要结合蛋白。初步研究表明，敲低新鉴定的伊曲康那结合蛋白导致内皮细胞中mTOR的抑制。此外，伊曲康唑结合蛋白下游的信号激酶也被发现被伊曲康唑激活，该蛋白已知是mTOR的负调节剂。本申请将集中在新鉴定的伊曲康唑结合蛋白作为直接靶点及其下游激酶作为伊曲康唑抗血管生成活性的关键介体的表征和验证上。还将尝试获得伊曲康唑与其假定靶点之间的复合物的晶体结构。通过系统地改变伊曲康唑的不同结构域来合成伊曲康唑的新类似物，以提高其抗血管生成效力、溶解度，同时降低其对CYP3A3药物代谢酶的抑制和肝毒性。希望该项目的成功完成将促进伊曲康唑及其类似物作为下一代新机制血管生成药物的临床开发。

DESCRIPTION (provided by applicant): In a screen of the Johns Hopkins Drug Library for inhibitors of endothelial cell proliferation, an antifungal drug, itraconazole, was identified as a novel inhibitor of angiogenesis. Earlier studies revealed several important cellular activities of itraconazole underlying its anti-angiogenic effect, including inhibition of endothelial cell cycle t G1 and mTOR signaling pathway. Itraconazole also showed remarkable anti-angiogenic activity in vitro and in various animal models of angiogenesis and tumor xenografts in vivo. Moreover, itraconazole has entered multiple Phase 2 human clinical studies as a new treatment of lung, prostate and skin cancer and how shown significant efficacy. Using a clickable photoaffinity probe of itraconazole, a major binding protein of itraconazole has been identified. Preliminary studies showed that knocking down of newly identified itraconazle-binding protein led to the inhibition of mTOR in endothelial cells. Furthermore, a signaling kinase downstream of the itraconazole-binding protein that is known to be a negative regulator of mTOR was also found to be activated by itraconazole. This application will be focused on the characterization and validation of the newly identified itraconazole-binding protein as a direct target and its downstream kinase as key mediator of the antiangiogenic activity of itraconazole. Attempts will also be made to obtain a crystal structure of the complex between itracoanzole and its putative target. New analogs of itraconazole will be synthesized by systematically altering the different structural domains of itraconazole to improve its anti-angiogenic potency, its solubility while decreasing its inhibition of CYP3A3 drug-metabolizing enzyme and its hepatotoxicity. It is hoped that the successful completion of the project will facilitate the clinical development of itraconazole and analogs as the next generation of a new mechanistic class of angiogenesis drugs.