G-Quadruplexes as Targets for Drug Design

该提案中描述的研究的总体目标是将一种小分子治疗药物 该药物用于治疗依赖c-Myc过表达生长的癌症的1期临床试验。 具体目的是（1）c-Myc启动子的NHE 1111中的i基序的结构表征 及其与TMPyP 4的复合物，（2）以确定NHE 1111元件的构象状态， 存在于短线性双链体DNA分子中，以超螺旋质粒状态存在，并且在体内存在，然后 确定TMPyP 4的结合如何影响这些形式的结构，（3）建立体外生物化学 和基于细胞的筛选以鉴定与细胞中的I基序结构特异性相互作用的小分子。 c-Myc启动子的沉默元件;（4）发现并优化新的i-motif相互作用化合物 使用基于结构的方法进行化合物文库的虚拟筛选、从头设计和后续研究 活性先导分子的优化，以及（5）体内和体外评价以及随后的临床前 发展我们最近发现了一种新的基因表达沉默机制， 二级DMA结构，其适合于小分子靶向以特异性调节基因 表情我们最近的研究结果表明，NHE 1111元件中的i基序是 调节c-Myc基因表达。原理证明已经存在于体外和体内，使用阳离子 卟啉。高场核磁共振和足迹技术将用于确定DNA的结构 元素及其药物复合物在无细胞、体外生化和体内系统中的应用。基于结构 设计和高通量筛选方法将用于鉴定小分子药物先导物。体外 并将进行体内评价，以在临床前开发和阶段之前评价这些电极导线 与Cylene Pharmaceuticals合作开展的1项临床试验。

The overall objective of the research described in this proposal is to bring a small molecule therapeutic agent into phase 1 clinical trails for treatment of cancers that depend upon c-Myc overexpression for growth. The specific aims are (1) structural characterization of the i-motif(s) in the NHE 1111 of the c-Myc promoter and its complex(es) with TMPyP4, (2) to determine the conformational state of the NHE 1111 element that exists in a short linear duplex DMA molecule, in a supercoiled plasmid state, and in vivo, and then to determine how binding of TMPyP4 affects the structure of these forms, (3) to establish in vitro biochemical and cell-based screens to identify small molecules that interact specifically with the i-motif structure in the silencer element of the c-Myc promoter, (4) To discover and optimize new i-motif-interactive compounds using structure-based approaches for virtual screening of compound libraries, de novo design, and follow-up optimization of active lead molecules, and (5) in vivo and in vitro evaluation and subsequent preclinical development. We have recently uncovered a novel mechanism for silencing of gene expression involving secondary DMA structures that is amenable to small molecule targeting to specifically modulate gene expression. Our recent results show that the i-motif in the NHE 1111 element is the druggable target for modulation of c-Myc gene expression. Proof of principle already exists in vitro and in vivo using a cationic porphyrin. High-field NMR and footprinting techniques will be used to determine the structure of the DNA element and its drug complexes in cell-free, in vitro biochemical, and in vivo systems. Structure-based design and high through-put screening methods will be used to identify small molecule drug leads. In vitro and in vivo evaluation will be carried out to evaluate these leads prior to preclinical development and phase 1 clinical trials carried out in collaboration with Cylene Pharmaceuticals.