Defining protein synthesis demands and specificities in multiple myeloma

定义多发性骨髓瘤的蛋白质合成需求和特异性

• 批准号: 10402290
• 负责人: James Andrew Saba
• 金额: $ 5.18万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-01 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10402290
• 关键词: 5' Untranslated Regions; Acute; Address; Adult; Antibodies; B cell differentiation; Biochemical; Biochemistry and Cellular Biology; Biological Models; Biology; Cancer cell line; Cell Line; Cell Lineage; Cells; Cessation of life; Clinical; Complex; Data; Data Analyses; Development; Diagnosis; Disease; Elements; Eukaryotic Initiation Factor-4F; Explosion; Genes; Goals; Health; Hematologic Neoplasms; Individual; Life; Life Expectancy; Literature; Malignant Neoplasms; Maps; Mediating; Mentors; Messenger RNA; Molecular Biology; Multiple Myeloma; Pharmaceutical Preparations; Pharmacology; Physicians; Plasma Cells; Play; Polyribosomes; Postdoctoral Fellow; Process; Production; Protein Biosynthesis; Proteins; Quality Control; Regulation; Research; Resources; Ribosomes; Scientist; Specificity; Structural Models; Techniques; Time; Training; Transcription Initiation Site; Translating; Translations; Universities; Work; biological adaptation to stress; cancer type; career; career development; cell type; doctoral student; drug development; druggable target; experience; experimental study; inhibitor; insight; interest; medical schools; new technology; new therapeutic target; programs; ribosome profiling; skills; symposium; translatome

PROJECT SUMMARY Multiple Myeloma (MM) is an incurable cancer of differentiated B lymphocytes (or “plasma cells”) which generally presents late in life and has a median life expectancy of ~4-7 years from time of diagnosis. MM cells are unusual among most other cell lineages, including other types of cancer, in that they synthesize large amounts of a single, nonfunctional protein. Despite this unique signature, the regulation of the protein synthesis machinery of the cell, the ribosome, remains poorly studied in MM. Recent evidence has advanced our understanding of a stress response cascade triggered downstream of the ribosome, which ranges from ribosome-mediated quality control (RQC) of single mRNAs to a “ribotoxic” stress response and global translational shutdown when fully activated. Importantly, preliminary data demonstrate that among 375 cancer cell lines, MM cells are among those that express the highest baseline levels of an upstream factor in this cascade, EDF1. Together, this suggests that RQC and the ribotoxic stress response may be generally activated at baseline in MM cells compared to other cell types. Beyond RQC and the ribotoxic stress response, MM cells are also differentially sensitive to inhibition of specific components the translational machinery of the cell, including all three subunits of the eukaryotic initiation factor 4F complex. Literature evidence and preliminary data suggest that MM cells may be hyper-dependent on the eIF4F complex to translate specific subsets of mRNAs which promote their proliferation or survival, but the identity of these mRNAs and mechanistic insight into why they are particularly dependent on eIF4F levels, both generally and in MM, is unclear. In this proposal, I seek to connect these ideas in order to understand how MM cells modulate the translational machinery to meet their unique protein synthesis demands. The central hypothesis of this proposal is that translation is broadly dysregulated in MM to allow high rates of protein synthesis and the translation of specific mRNAs which promote survival and proliferation. I propose to address this hypothesis through the following specific Aims: Aim 1: Characterize translation, quality control, and the ribotoxic stress response in MM; Aim 2: Define the eIF4F-sensitive translational landscape in MM; Aim 3: polysome-associated CAGE-seq (paCAGE) to interrogate translational control by 5'UTRs in MM. These aims will be achieved through a combination of biochemical and sequencing approaches in immortalized MM cell lines, including the development of a new technology which will be essential to identify 5'UTR sequence motifs within eIF4F-sensitive mRNAs. This work will be significant because it may reveal new therapeutic targets in multiple myeloma while elucidating important ribosomal biology which may be more generally involved in other model systems or disease states.

项目总结 多发性骨髓瘤(MM)是一种无法治愈的分化B淋巴细胞(或“浆细胞”)癌症 通常表现为晚年，从确诊之日起中位预期寿命为~4-7年。MM细胞 在大多数其他细胞系中是不寻常的，包括其他类型的癌症，因为它们合成了大量的 一种单一的、无功能蛋白质的数量。尽管有这个独特的特征，蛋白质合成的调节 核糖体这一细胞机制在MM中的研究仍然很少。最近的证据使我们的 了解核糖体下游触发的应激反应级联反应，范围从 核糖体介导的单个mRNAs对“核毒”应激反应和全球的质量控制 完全激活时转换关闭。重要的是，初步数据表明，在375种癌症中 细胞系，MM细胞是表达该基因上游因子最高基线水平的细胞之一 CASCADE，EDF1。总之，这表明RQC和核毒应激反应可能普遍被激活。 与其他细胞类型相比，MM细胞处于基线状态。除了RQC和核毒性应激反应，MM细胞 对细胞的翻译机制的特定成分的抑制也是不同的敏感， 包括真核细胞起始因子4F复合体的所有三个亚基。文献证据和初步证据 数据表明，MM细胞可能高度依赖eIF4F复合体来翻译特定的亚群 促进它们增殖或生存的mRNAs，但这些mRNAs的身份和机械论的洞察力 至于为什么他们特别依赖eIF4F水平，无论是在一般情况下还是在MM中，目前尚不清楚。在这份提案中， 我试图将这些想法联系起来，以便理解MM细胞如何调节翻译机制来 满足它们独特的蛋白质合成需求。这一提议的中心假设是，翻译是 在多发性骨髓瘤中广泛失调，允许蛋白质合成和翻译特定的mRNAs的高速率 促进生存和扩散。我建议通过以下具体目标来解决这一假设： 目标1：描述多发性骨髓瘤的翻译、质量控制和核毒性应激反应；目标2：定义 MM中对eIF4F敏感的翻译景观；目标3：要询问的多聚体相关笼状序列(Paage) 在MM中通过5‘UTRs进行翻译控制。这些目标将通过生物化学和 永生化MM细胞系的测序方法，包括开发一种新技术，该技术 对于识别eIF4F敏感的mRNAs中的5‘UTR序列基序至关重要。这项工作将是意义重大的 因为它可能揭示多发性骨髓瘤的新治疗靶点，同时阐明重要的核糖体 生物学，可能更广泛地涉及其他模型系统或疾病状态。