Structure-based design of novel low molecular weight c-Myc inhibitors

基于结构的新型低分子量 c-Myc 抑制剂的设计

• 批准号: 8269082
• 负责人: Edward Victor Prochownik
• 金额: $ 53.41万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8269082
• 关键词: Binding; Binding Sites; Biochemical; Biological; Biological Assay; Cell Proliferation; Cells; Computer Simulation; Computing Methodologies; Dimerization; Disease; Drug Kinetics; Drug or chemical Tissue Distribution; Generations; Health; Heterodimerization; Human; In Vitro; Institution; Link; Malignant Neoplasms; Mediating; Metabolism; Modeling; Modification; Molecular; Molecular Abnormality; Molecular Conformation; Molecular Weight; NMR Spectroscopy; Neoplasms; Normal Cell; Oncogene Proteins; Oncogenes; Outcome Study; Pediatric Oncologist; Regulation; Research Personnel; Series; Site; Specificity; Structural Models; Structure; Testing; Toxic effect; Xenograft Model; ZIP protein; analog; base; c-myc Genes; design; efficacy testing; improved; in vivo; inhibitor/antagonist; insight; member; monomer; multidisciplinary; novel; pre-clinical; prevent; small molecule; synthetic peptide; therapeutic target; three dimensional structure; three-dimensional modeling; transcription factor; tumor

DESCRIPTION (provided by applicant): De-regulation of the C-MYC oncogene is among the most frequent molecular abnormalities in human cancer. c-Myc is a bHLH-ZIP transcription factor whose dimerization with another bHLH-ZIP protein, Max, is necessary for transformation and all other biological activities. That c-Myc is indispensable for cell proliferation, that most normal cells are non-cycling and thus non-c-Myc-expressing, and that transient inhibition of c-Myc may be sufficient to achieve permanent tumor regression, makes therapeutic targeting of the oncoprotein highly appealing. We have previously identified 7 low molecular weight compounds that abrogate/prevent bHLH-ZIP-mediated c-Myc-Max heterodimerization ("Myc compounds"). Non structure- guided (i.e. "unbiased") modifications of one of these has resulted in the generation of "2nd generation" analogs with up to 8-fold enhanced potencies, thus demonstrating that significant improvements in compound efficacy can be obtained even in the absence of a model of the compound in association with its target site. In order to identify even better analogs in a more rational and meaningful way, we have demonstrated that 3 of our original Myc compounds bind to distinct sites on the intrinsically disordered c- Myc bHLH-ZIP monomer, alter its secondary structure, and prevent its association with Max. The remaining 4 compounds are redundant and bind to one of these sites. Using NMR spectroscopy, we have generated structural models of the first three compounds in association with synthetic peptides comprising their cognate binding sites. Thus, in Specific Aim 1, we will utilize computational methods and high throughput in silico screens to identify new and more potent "3rd generation" analogs whose structures are rationally predicated on those of the original 3 founding members. In Specific Aim 2, we will compare the abilities of these new compounds to inhibit c-Myc-Max association and c-Myc-mediated neoplastic growth. In Specific Aim 3, we will conduct in vivo pharmacologic testing of the most promising analogs prioritized by their "ADMET" profiles. Finally, in Specific Aim 4, selected analogs identified in Specific Aims 2 and 3 will be chemically linked in order to generate "4th generation" compounds capable of simultaneous binding to two distinct sites on the c-Myc bHLH-ZIP domain. This proposal is highly interdisciplinary and interactive in that it utilizes the expertise of a pediatric oncologist/molecular biologist (Prochownik), an organic chemist (Metallo), computational biologists (Behar and Mustata), and pharmacologists (Lazo, Eiseman and Egorin). Together, this diverse, complementary, and synergistic group of investigators, from two institutions, proposes studies that promise new insights regarding the rational design of Myc compounds and the mechanisms by which they disable this critical oncoprotein. PUBLIC HEALTH RELEVANCE: This highly focused application is a multidisciplinary translational effort by seven investigators from two institutions to develop rationally designed small molecules that target the c-Myc oncoprotein. We have already determined the 3D NMR structures of three compounds that bind directly to different sites on the c-Myc monomer and inhibit its activity. Using these as a starting point, we propose to design and characterize a series of more potent analogs, some of which will be chemically linked to provide synergistic binding and biological activities.

描述（由申请人提供）：C-MYC癌基因的去调控是人类癌症中最常见的分子异常之一。c-Myc是一种bHLH-ZIP转录因子，它与另一种bHLH-ZIP蛋白Max二聚化是转化和所有其他生物活性所必需的。c-Myc对于细胞增殖是必不可少的，大多数正常细胞是非循环的，因此不表达c-Myc，并且c-Myc的短暂抑制可能足以实现永久性肿瘤消退，这使得肿瘤蛋白的治疗靶向非常有吸引力。我们之前已经鉴定了7种低分子量化合物，它们可以消除/阻止bhlh - zip介导的c-Myc-Max异二聚化（“Myc化合物”）。非结构导向(即：“无偏”)对其中一种的修改导致了“第二代”类似物的产生，其效力提高了8倍，从而表明即使没有与目标位点相关的化合物模型，也可以获得化合物功效的显着改善。为了以更合理和有意义的方式识别更好的类似物，我们已经证明了我们的3个原始Myc化合物与内在无序的c- Myc bHLH-ZIP单体上的不同位点结合，改变其二级结构，并阻止其与Max的结合。其余4个化合物是冗余的，并与这些位点中的一个结合。利用核磁共振波谱，我们生成了前三种化合物的结构模型，这些化合物与包含其同源结合位点的合成肽相关联。因此，在具体目标1中，我们将利用计算方法和高通量的硅屏幕来识别新的和更有效的“第三代”类似物，其结构合理地基于原始3个创始成员的结构。在特异性目标2中，我们将比较这些新化合物抑制c-Myc-Max关联和c- myc介导的肿瘤生长的能力。在Specific Aim 3中，我们将对最有希望的类似物进行体内药理学测试，根据它们的“ADMET”特征进行优先排序。最后，在Specific Aim 4中，将在Specific Aims 2和3中鉴定的选定类似物进行化学连接，以生成能够同时结合c-Myc bHLH-ZIP结构域上两个不同位点的“第四代”化合物。该提案是高度跨学科和互动的，因为它利用了儿科肿瘤学家/分子生物学家（Prochownik），有机化学家（Metallo），计算生物学家（Behar和Mustata）和药理学家（Lazo， Eiseman和Egorin）的专业知识。来自两个机构的这一多样化、互补和协同的研究小组共同提出的研究有望为Myc化合物的合理设计以及它们使这种关键癌蛋白失活的机制提供新的见解。公共卫生相关性：这一高度集中的应用是由来自两个机构的七名研究人员开发合理设计的靶向c-Myc癌蛋白的小分子的多学科转化努力。我们已经确定了三种化合物的三维核磁共振结构，它们直接结合到c-Myc单体上的不同位点并抑制其活性。以此为出发点，我们建议设计和表征一系列更有效的类似物，其中一些将化学连接以提供协同结合和生物活性。