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（申请人提供）：通过 G-四链体相互作用小分子调节 c-MYC 转录 最近发现 DNA G-四链体二级结构在近端启动子区域形成作为转录调节因子，并被认为是抗癌药物的一类新型分子靶标。具体来说，c-MYC 是人类癌症中最常见失调的基因之一，其启动子核酸酶超敏元件 (NHE) III1 中有一个 DNA G 四链体基序，可调节其总转录的 80-95%。 c-MYC NHE III1 中形成的 DNA G-四链体已被证明是转录沉默元件；结合并稳定G-四链体构象的化合物可以减少c-MYC表达并且具有抗肿瘤作用。我们最近发现NM23-H2蛋白展开c-MYC启动子G-四联体来激活基因转录。然而，尽管 c-MYC 启动子 G-四链体是第一个也是研究最广泛的系统，但人们对其与小分子和蛋白质的分子相互作用知之甚少。要测试的假设是c-MYC G-四链体相互作用化合物的生理功能不仅通过G-四链体而且还通过G-四链体相互作用蛋白介导。我们已确定玫瑰树碱类似物作为我们的先导化合物，用于进一步优化以靶向 c-MYC 启动子 G-四联体。玫瑰树碱具有良好的“类药物”特性，并已被证明可以选择性结合 c-MYC G-四链体。我们将使用 NMR 来了解与 c-MYC G-四链体的分子相互作用，并使用 ITC 来表征药物结合的热力学贡献（目标 1）。基于这些信息，我们将合理设计和合成在C9、N2、N6和C3位上具有各种取代基的新玫瑰树碱类似物（目标2）。我们将使用生化、生物物理和生物测定来检查 Ellipticines 对抑制 NM23-H2 结合和 c-MYC G-四联体解折叠的作用及其在 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了解玫瑰树碱的特定 G-四链体相互作用，从而抑制 NM23-H2 蛋白和抑制 c-MYC 转录。本研究的总体目标是建立玫瑰树碱抑制 c-MYC 的结构-活性关系和潜在分子机制，并设计/合成新的类似物以供进一步的药物开发。具体目标是： 1) 确定玫瑰树碱及相关分子与 c-MYC G-四联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取代的玫瑰树碱类似物，并研究针对c-MYC G-四链体的玫瑰树碱的构效关系(SAR)。 3) 确定玫瑰树碱类似物如何调节 NM23-H2 结合和 c-MYC G-四链体的解折叠，以及这如何与 c-MYC 转录抑制相关。