Modulating c-Myc transcription by G-quadruplex-interactive small molecules

通过 G-四链体相互作用小分子调节 c-Myc 转录

• 批准号: 8648365
• 负责人: DANZHOU YANG
• 金额: $ 36.96万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-06-01 至 2019-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8648365
• 关键词: Affect; Antineoplastic Agents; Binding; Biochemical; Biological; Biological Assay; Complement; Complex; DNA; Data; EMSA; Effectiveness; Elements; Ellipticines; Exons; Fluorescence Resonance Energy Transfer; G-Quartets; Gene Expression; Genes; Genetic Transcription; Human; In Vitro; Lead; Luciferases; MYC gene; Malignant Neoplasms; Mediating; Molecular; Molecular Conformation; Molecular Target; NME1 gene; Pharmaceutical Preparations; Physiological; Positioning Attribute; Promoter Regions; Property; Protein Binding; Proteins; Reporter; Research; Structure; Structure-Activity Relationship; System; Testing; Therapeutic; Thermodynamics; Transcription Coactivator; Transcriptional Silencer Elements; analog; base; c-myc Genes; cyclic compound; design; drug development; ellipticine; functional group; improved; in vivo; novel; novel strategies; nuclease; pharmacophore; promoter; public health relevance; small molecule; tumorigenic

DESCRIPTION (provided by applicant): Modulating c-MYC Transcription by G-quadruplex-interactive Small Molecules DNA G-quadruplex secondary structures have recently been found to form in proximal promoter regions as transcriptional regulators, and are considered as a new class of molecular targets for anticancer drugs. Specifically, c-MYC, one of the most commonly deregulated genes in human cancers, has a DNA G-quadruplex motif in the promoter Nuclease Hypersensitive Element (NHE) III1 which regulates 80-95% of its total transcription. The DNA G-quadruplex formed in the c-MYC NHE III1 has been shown to be a transcriptional silencer element; compounds that bind to and stabilize the G-quadruplex conformation can reduce c-MYC expression and are anti- tumorigenic. We have recently discovered that the NM23-H2 protein unfolds the c-MYC promoter G-quadruplex to activate gene transcription. However, although the c-MYC promoter G-quadruplex is the first and most extensively studied system, little is known about its molecular interactions with small molecules and proteins. The hypothesis to be tested is that the physiological functions of c-MYC G-quadruplex-interactive compounds are mediated through not only the G-quadruplex but also the G-quadruplex-interactive protein. We have identified an Ellipticine analog as our lead compound for further optimization to target the c-MYC promoter G- quadruplex. Ellipticine has good "drug-like" properties and has been shown to selectively bind the c-MYC G-quadruplex. We will use NMR to understand the molecular interactions with the c- MYC G-quadruplex and ITC to characterize the thermodynamic contributions of drug binding (Aim 1). Based on this information, we will rationally design and synthesize new Ellipticine analogs with various substituents at C9, N2, N6, and C3 positions (Aim 2). We will use biochemical, biophysical, and biological assays to examine the effects of the Ellipticines on inhibiting NM23-H2 binding and unfolding of the c-MYC G-quadruplex and their effectiveness in c-MYC transcriptional suppression. A combination of structural and biological studies will allow us to understand the specific G-quadruplex interactions of Ellipticine that lead to inhibition of the NM23-H2 protein and suppression of c-MYC transcription. The overall objectives of this research are to establish the structure-activity relationship and underlying molecular mechanism of Ellipticines for c-MYC suppression and to design/synthesize new analogs for further drug development. The specific aims are: 1) To determine structural and thermodynamic details of molecular interactions of Ellipticines and related molecules with the c-MYC G- quadruplex. 2) To design and synthesize new C9-, N2-, N6-, and C3-substituted Ellipticine analogs and to study structure-activity relationship (SAR) of Ellipticines targeting the c-MYC G- quadruplex. 3) To determine how Ellipticine analogs modulate NM23-H2 binding and unfolding of the c-MYC G-quadruplex, and how this correlates with c-MYC transcriptional suppression.

描述（由申请人提供）：最近发现，G-四链体相互作用的小分子DNA G-四链体二级结构在近端启动子区域中形成了C-MYC转录，被视为转录调节剂，被认为是抗癌药物的新分子靶标。具体而言，c-Myc是人类癌症中最常见的失控基因之一，在启动子核酸酶超敏元素（NHE）III1中具有DNA G-四链体基序，可调节其总转录的80-95％。在C-Myc NHE III1中形成的DNA G四链体已被证明是转录消音器元件。结合并稳定G-四链体构象的化合物可以降低C-MYC表达并具有抗肿瘤性。我们最近发现，NM23-H2蛋白展开C-MYC启动子G-四链体以激活基因转录。然而，尽管C-MYC启动子G-四链体是第一个也是最广泛研究的系统，但对其与小分子和蛋白质的分子相互作用知之甚少。要检验的假设是，C-Myc G Qu-二链体相互作用化合物的生理功能不仅是通过G-四链体介导的，还可以通过G-四链体相互作用蛋白来介导。我们已经将椭圆类似物鉴定为我们的铅化合物，以进一步优化，以靶向C-MYC启动子G-四链体。椭圆氨酸具有良好的“药物样”特性，并已被证明可以选择性地结合C-MYC G-四链体。我们将使用NMR了解与C- myc G-四链体和ITC的分子相互作用，以表征药物结合的热力学贡献（AIM 1）。基于这些信息，我们将在C9，N2，N6和C3位置合理设计并合成各种取代基的新椭圆类似物（AIM 2）。我们将使用生化，生物物理和生物学测定法检查椭圆氨酸对C-MYC G Qu-Quadruplex抑制NM23-H2结合的影响及其在C-MYC转录抑制中的有效性。结构和生物学研究的结合将使我们能够理解椭圆氨酸的特异性G四链体相互作用，从而导致抑制NM23-H2蛋白和C-MYC转录的抑制。这项研究的总体目的是建立椭圆氨酸的结构活性关系和基本的分子机制，以抑制C-MYC，并设计/合成新的类似物，以进一步开发药物。具体目的是：1）确定椭圆类和相关分子与C-MYC G-四倍体的分子相互作用的结构和热力学细节。 2）设计和合成新的C9-，N2-，N6-和C3取代的椭圆类类似物，并研究针对C-Myc G-四倍体的椭圆氨酸的结构活性关系（SAR）。 3）确定椭圆氨酸类似物如何调节C-MYC G Qu-Quadruplex的NM23-H2结合和展开，以及这与C-MYC转录抑制的相关性。