G-quadruplexes formed in human oncogene promoters and their drug complexes

描述（由申请人提供）：四种癌基因c-MYC、bcl-2、VEGF和HIF-1a在其启动子区均含有对转录激活至关重要的polyG/polyC片段。DNA G-四链体二级结构的发生已被证明在这四个癌基因的启动子区域，并已被证明是一个转录调节因子。虽然DNA G-四链体是有前途的新药物靶点，但其作为癌症治疗靶点的潜力的评估取决于对生物学相关的G-四链体结构的理解。我们的初步研究使我们能够确定在c-MYC，bcl-2，VEGF和HIF-1a的启动子区域中G-四链体的主要形式，它们似乎代表三种不同的基本G-四链体结构，其中VEGF/HIF-1a G-四链体是相同的基本类型。启动子G-四链体的不同分子结构使这些结构成为途径特异性药物设计的有吸引力的目标。在这个提议中，我们打算定义每个G-四链体及其药物复合物的特定分子结构。将获得的结构信息与生物学数据相关联，以了解有效的基因调控。深入了解启动子G-四链体及其药物复合物的结构将为基于结构的合理药物设计提供重要依据。我们将检验我们的假设，即每个启动子G-四链体可以被不同的小分子药物化合物特异性靶向。除了可以通过与不同的G-四链体核心结构的相互作用实现选择性的原理之外，我们预计选择性也可以通过外部环和其中产生结合口袋的封端结构内的相互作用来实现。在这方面，原则的证明将是重要的。我们将使用NMR，CD，分子模拟和微量热数据的组合与适当的突变启动子元素。我们的主要方法，高场NMR光谱，代表了一个主要的工具，用于生物相关的G-四链体的结构测定，由于结晶的困难，这样的结构。我们的最终目标是使用基于结构的方法来合理设计小分子G-四链体相互作用的化合物，其特异性靶向每个启动子所特有的G-四链体结构并调节基因转录。具体而言，我们计划1）确定c-MYC启动子区形成的生物学相关的G-四链体的分子结构及其药物相互作用; 2）确定bcl-2启动子区形成的生物学相关的G-四链体的分子结构及其药物相互作用;和3）确定VEGF/HIF-1 α启动子区形成的生物学相关的G-四链体的分子结构及其药物相互作用。

DESCRIPTION (provided by applicant): The four oncogenes, c-MYC, bcl-2, VEGF, and HIF-1a, all contain polyG/polyC tracts in their promoter regions critical for transcriptional activation. The occurrence of DNA G-quadruplex secondary structures has been demonstrated in the promoter regions of these four oncogenes and has been shown to be a transcriptional modulator. While the DNA G-quadruplexes are promising new drug targets, the evaluation of their potential as cancer therapeutic targets depends on the understanding of biologically relevant G-quadruplex structures. Our preliminary studies have allowed us to identify the predominant forms of G-quadruplexes in the promoter regions of c-MYC, bcl-2, VEGF, and HIF-1a, which appear to represent three different basic G-quadruplex structures with VEGF/HIF-1a G-quadruplexes being the same basic type. The different molecular structures of the promoter G-quadruplexes make these structures attractive targets for pathway-specific drug design. In this proposal we intend to define the specific molecular structure of each G-quadruplex and its drug-complex(es). The structural information obtained will be correlated with the biological data to understand the effective gene modulation. Insight into the structures of the promoter G-quadruplexes and their drug complexes will provide an important basis for structure-based rational drug design. We will test our hypothesis that each promoter G-quadruplex can be specifically targeted by different small molecule drug compounds. In addition to the principle that selectivity can be achieved by interactions with different G-quadruplex core structures, we expect that selectivity can also be achieved by interactions within the external loops and capping structures in which binding pockets are generated. Proof of principle will be important in this regard. We will use a combination of NMR, CD, molecular modeling, and microcalorimetry data in concert with appropriate mutant promoter elements. Our primary approach, high field NMR spectroscopy, represents a major tool for structure determination of biologically relevant G-quadruplexes, due to the difficulty of crystallization of such structures. Our ultimate objective is to use a structure-based approach to rationally design small molecule G-quadruplex-interactive compounds that specifically target the G-quadruplex structure unique to each promoter and modulate gene transcription. Specifically, we plan to 1) determine the molecular structure of the biologically relevant G-quadruplex formed in the promoter region of c-MYC and its drug interactions; 2) determine the molecular structure of the biologically relevant G-quadruplex formed in the promoter region of bcl-2 and its drug interactions; and 3) determine the molecular structure of the biologically relevant G-quadruplex formed in the promoter region of VEGF/HIF-1a and its drug interactions.