Identification of chemosensitizing agents that block DNA repair by the Fanconi Anemia/Bloom Dissolvasome complex

摘要： 几种成熟的癌症治疗方法利用了癌细胞对DNA损伤的过敏性 通过对细胞DNA造成全基因组的破坏。然而，肿瘤通常会进化出对DNA损伤的抵抗力。 化疗药物通过提高DNA修复途径的活性，变得依赖于特定的修复 为了生存的活动。这些观察使治疗方法选择性地针对个体DNA修复 蛋白质，特别是那些参与治疗耐药的蛋白质，具有很高的价值。阻断血管活性的抑制剂 DNA修复蛋白多聚腺苷二磷酸核糖聚合酶是一种特异性修复抑制物，表现出很好的 作为化疗药物的承诺。这项提议将这种方法扩展到靶向一种新的化疗DNA。 通过开发小分子来阻断连接两个DNA修复的关键界面的修复途径 已知与肿瘤化疗耐药有关的复合体--Fanconi贫血复合体和 布卢姆解毒剂。X射线结晶学、生化和细胞生物学方法揭示了 这种高阶复合体对细胞基因组稳定性的关键性质及其作为一种新疗法的前景 目标。此外，我还开发了一种出色的高通量筛查准备策略，该策略已经 在一项初步研究中确定了少量的抑制剂。在这份提案中，我将进行一次大规模的高考-- 通过化学筛选确定破坏蛋白质形成的蛋白质相互作用抑制物 范可尼贫血-布卢姆溶酶体超复合体。生化、结构和细胞方法将是 用于评估抑制剂的效力和作用机制，并推动合理的铅改善。 先导化合物的化学治疗潜力将通过测量它们对 通过评估超复合体是否选择性抑制修复特定类型的DNA损伤 作为单一疗法和临床化疗佐剂的人类癌细胞系的生长。

Abstract: Several established cancer treatments take advantage of the hypersensitivity of cancer cells to DNA damage by inducing genome-wide damage to cellular DNA. However, tumors often evolve resistance to DNA-damaging chemotherapeutics by elevating the activities of DNA repair pathways, becoming dependent on specific repair activities for survival. These observations make therapeutics that selectively target individual DNA repair proteins, especially those involved in therapeutic resistance, highly valuable. Inhibitors that block activity of the DNA repair protein poly-ADP ribose polymerase are one example of specific repair inhibitors that show great promise as chemotherapeutics. This proposal extends this approach to target a novel chemotherapeutic DNA repair pathway by developing small-molecules that block the critical interface linking two DNA repair complexes known to be involved in tumor chemotherapeutic resistance -- the Fanconi Anemia complex and the Bloom Dissolvasome. X-ray crystallographic, biochemical, and cell biological approaches have revealed the critical nature of this higher-order complex for cellular genomic stability and its promise as a novel therapeutic target. In addition, I have developed an excellent high throughput screening ready strategy that has already identified a small number of inhibitors in a pilot study. In this proposal, I will carry out a large-scale high- throughput chemical screen to identify protein-protein interaction inhibitors that disrupt the formation of the Fanconi Anemia-Bloom Dissolvasome supercomplex. Biochemical, structural, and cellular approaches will be used to assess the potency and mechanisms of action of the inhibitors and to drive rational lead improvement. The chemotherapeutic potential of the lead compounds will be determined by measuring their effects on the specific types of DNA damage repaired by the supercomplex and by assessing whether they selectively inhibit growth of human cancer cell lines as monotherapies and as adjuvants with clinical chemotherapeutics.