Screen for Inhibitors of La-dependent IRES-mediated Translation in Cancer Cells

筛选癌细胞中 La 依赖性 IRES 介导的翻译抑制剂

• 批准号: 8528283
• 负责人: Tilman Heise
• 金额: $ 31万
• 依托单位: MEDICAL UNIVERSITY OF SOUTH CAROLINA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-05-03 至 2016-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8528283
• 关键词: 2-cyclopentyl-5-(5-isoquinolylsulfonyl)-6-nitro-1H-benzo(D)imidazole; Accounting; Antineoplastic Agents; Binding; Binding Sites; Biological; Biological Assay; Cancerous; Cell Proliferation; Cells; Cellular Stress; Cyclin D1; Data; Development; Drug Targeting; Elements; Fluorescence; Fostering; Genetic Translation; Goals; Hela Cells; Hypoxia; Internal Ribosome Entry Site; Knowledge; Label; Laboratories; Laminin; Lead; Life; Malignant Neoplasms; Malignant neoplasm of cervix uteri; Maps; Measures; Mediating; Messenger RNA; Mission; Molecular; Molecular Bank; Molecular Chaperones; Normal Cell; Oncogenes; Oral; Play; Production; Protein Biosynthesis; Proteins; Public Health; Publishing; RNA; RNA Binding; RNA-Binding Proteins; RNA-Protein Interaction; Research; Role; Small Interfering RNA; Solid Neoplasm; Specificity; Starvation; Stress; Structure; Tertiary Protein Structure; Testing; Therapeutic; Time; Trans-Activators; Translating; Translation Initiation; Translations; base; cancer cell; drug discovery; fighting; high throughput screening; human BIRC4 protein; human disease; inhibitor/antagonist; innovation; irradiation; migration; mutant; novel; novel therapeutic intervention; novel therapeutics; overexpression; protein expression; public health relevance; screening; small molecule; tumor; tumor progression; tumorigenesis

DESCRIPTION (provided by applicant): Protein translation is an essential and highly regulated cellular mechanism leading to the expression of proteins. However, protein synthesis is often miss-regulated in human diseases, such as cancer. Translation initiation occurs normally in a cap-dependent mechanism but in stressed and cancerous cells translation initiation might be mediated via Internal Ribosome Entry Sites (IRES). IRES-mediated translation accounts for the expression of some tumor-promoting factors in stressed and cancerous cells. Auxiliary RNA-binding proteins, referred to as IRES-Trans-Acting Factors (ITAF), support IRES-mediated translation. Thus, targeting specific ITAF:IRES interactions required to stimulate the IRES-mediated translation of tumor-promoting factors represents an innovative therapeutic approach and targets a cellular mechanism often activated in cancerous cells. Our long-term goal is to identify small molecule inhibitors for specific ITAF:IRES interactions, to demonstrate their functionality in repressing selectively the translation of tumor promoting factors and to develop such molecules to novel anti-cancer drugs. To reach this goal the research in the applicant's laboratory focused on the development of high-throughput assays to screen for compounds inhibiting the functionality of the RNA-binding protein La, a well-known ITAF. The applicant recently published that the ITAF La is overexpressed in different types of tumors (e.g. oral, cervical cancer), stimulates cell proliferation and acts as ITAF during IRES-depending translation of tumor-promoting factors, such as the cooperative oncogene cyclin D1. The central hypothesis is that small molecule inhibitors of La-stimulated cyclin D1 IRES-mediated translation will reduce proliferation of cancerous cells. The rationale is that we found that depletion of La in cancerous cells reduce cyclin D1 expression and cell proliferation. Our strong set of preliminary data guided us to develop three Specific Aims to challenge our hypothesis. In Specific Aim 1: we aim to screen for small molecules inhibiting the functionality the RNA-binding protein La. In Specific Aim 2 we anticipated to demonstrate activity and specificity of compounds identified in the primary screen, and finally in Specific Aim 3 we wish to demonstrate the functionality of lead compounds in cell-based assays. The approach is innovative because it uses novel HTS-assays to screen for inhibitors of protein:RNA interactions which playing a critical role in tumorigenesis. The proposed research is significant, because identification of novel molecules inhibiting La:RNA interactions would signify a proof of concept. Furthermore it is anticipated that the proposed research would represents a substantive departure from the status quo and would illuminate the extremely wide and diverse field of protein:RNA interactions as potential drug target. Ultimately, such knowledge might be translated into new therapeutic strategies targeting the expression of tumor-promoting factors in cancer.

描述（由申请人提供）：蛋白质翻译是导致蛋白质表达的基本和高度调节的细胞机制。然而，蛋白质合成在人类疾病如癌症中经常被错误调节。翻译起始通常以帽依赖性机制发生，但在应激和癌细胞中，翻译起始可能通过内部核糖体进入位点（IRES）介导。IRES介导的翻译解释了一些促肿瘤因子在应激和癌细胞中的表达。辅助RNA结合蛋白，称为IRES-反式作用因子（ITAF），支持IRES介导的翻译。因此，靶向刺激IRES介导的肿瘤促进因子翻译所需的特异性ITAF：IRES相互作用代表了一种创新的治疗方法，并靶向癌细胞中经常激活的细胞机制。我们的长期目标是鉴定特异性ITAF：IRES相互作用的小分子抑制剂，以证明它们在选择性抑制肿瘤细胞翻译中的功能。 促进因子，并将此类分子开发为新型抗癌药物。为了实现这一目标，申请人实验室的研究集中在开发高通量测定以筛选抑制RNA结合蛋白La（一种众所周知的ITAF）的功能性的化合物。申请人最近公开了ITAF La在不同类型的肿瘤（例如口腔癌、宫颈癌）中过表达，刺激细胞增殖并在肿瘤生长过程中充当ITAF。 IRES依赖性肿瘤促进因子的翻译，如协同致癌基因细胞周期蛋白D1。中心假设是La刺激的细胞周期蛋白D1 IRES介导的翻译的小分子抑制剂将减少癌细胞的增殖。其基本原理是，我们发现，在癌细胞中的La消耗减少细胞周期蛋白D1的表达和细胞增殖。我们强大的初步数据集引导我们制定了三个具体目标来挑战我们的假设。在具体目标1中：我们的目标是筛选抑制RNA结合蛋白La功能的小分子。在具体目标2中，我们期望证明在初步筛选中鉴定的化合物的活性和特异性，最后在具体目标3中，我们希望 证明了先导化合物在基于细胞的测定中的功能性。该方法是创新的，因为它使用新的HTS测定来筛选蛋白质：RNA相互作用的抑制剂，这在肿瘤发生中起着关键作用。拟议的研究是重要的，因为鉴定抑制La：RNA相互作用的新分子将意味着概念的证明。此外，预计拟议的研究将代表与现状的实质性偏离，并将阐明蛋白质：RNA相互作用作为潜在药物靶点的极其广泛和多样化的领域。最终，这些知识可能会转化为针对癌症中肿瘤促进因子表达的新治疗策略。