Exploiting myeloma proteome remodeling to extend proteasome inhibitor efficacy

利用骨髓瘤蛋白质组重塑来延长蛋白酶体抑制剂的功效

• 批准号: 10341162
• 负责人: Arun P. Wiita
• 金额: $ 27.82万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10341162
• 关键词: Active Sites; Address; Alternative Splicing; Apoptosis; Apoptotic; Architecture; Biochemical; Biological Assay; Bortezomib; CRISPR interference; Cell Death; Cell Line; Cells; Cellular biology; Clinical; Clinical Trials; Complex; Data; Diagnosis; Disease; Event; Exons; Exposure to; FDA approved; Family; Genetic; Genetic Transcription; Goals; Heat shock proteins; Heat-Shock Proteins 70; Hematologic Neoplasms; Hematopoietic Neoplasms; Immunoglobulins; Introns; Investigation; Kinetics; Lead; Longevity; Malignant - descriptor; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Methods; Modification; Molecular Chaperones; Monitor; Multiple Myeloma; Mutation; Outcome; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacology; Phosphorylation; Physiologic pulse; Plasma Cells; Post-Translational Protein Processing; Proteasome Inhibition; Proteasome Inhibitor; Protein Biosynthesis; Proteins; Proteome; Proteomics; RNA Splicing; Refractory; Relapse; Resistance; Role; Sampling; Signal Transduction; Spliceosomes; System; Therapeutic; Time; Transcript; Treatment Efficacy; Ubiquitin; base; cell type; clinically relevant; combat; follow-up; functional genomics; genomic data; improved; in vivo Model; inhibitor; insight; knock-down; mRNA Precursor; mouse model; multicatalytic endopeptidase complex; neoplastic cell; novel; novel therapeutic intervention; novel therapeutics; phosphoproteomics; pre-clinical; protein degradation; protein folding; proteostasis; response; small molecule inhibitor; synergism; therapy resistant; tool; transcriptome sequencing; treatment strategy; valosin-containing protein

PROJECT SUMMARY/ABSTRACT Multiple myeloma is an aggressive hematologic malignancy that remains incurable despite recent progress. This disease of malignant plasma cells is fundamentally associated with aberrant protein homeostasis, defined by an extremely high burden of immunoglobulin synthesis. Proteasome inhibitors (PIs), a widely-used first-line therapy in myeloma, are thought to directly take advantage of this aberrancy by increasing unfolded protein stress leading to cell death. However, this mechanism is not fully proven, and further insight into PI-induced cell death may lead to more effective combination strategies. In addition, PI resistance is a major clinical problem in myeloma, and new strategies are needed to overcome this condition. Here, we hypothesize that the remodeling of the plasma cell proteome after therapy is central to both PI response and resistance. We specifically propose that proteome remodeling is mediated through rewiring of proteostasis pathways involving chaperones, the VCP/p97 complex, and the ubiquitin-proteasome system, as well as through changes to the alternative splicing landscape, as mediated by post-translational modification of the splicing machinery. To explore this hypothesis we will take advantage of novel pharmacologic and genetic perturbation tools, cellular and biochemical assays, in vivo models, clinical trial genomic data, primary sample analysis, RNA sequencing, and mass spectrometry approaches. The overall goals of this proposal are 1) develop new therapy strategies either in combination with PIs or in the PI-refractory setting, and 2) describe a new, systematic approach to probe the architecture of proteostasis networks. Importantly, our preliminary results challenge existing paradigms related to PI efficacy. In Aim 1, we address paradoxical findings relating the unfolded protein response, the interaction between the p97 degradation machinery and PIs, and the relevance of inducible HSP-family chaperones. We will take advantage of novel pharmacology available to us, including active site and allosteric inhibitors of p97 and allosteric inhibitors of HSP70, in combination with functional genetics by CRISPR interference, to define the role of central protein homeostasis nodes defining PI response and resistance. Furthermore, we will use our unique expertise in pulsed-SILAC proteomics to determine specific substrates of the p97 machinery and the proteasome in the presence of clinically-relevant resistance modifications. Toward Aim 2, our preliminary studies using unbiased mass spectrometry have revealed significant phosphorylation of the spliceosome after PI treatment. We first aim to characterize the relationship between specific alternative splicing events and proteome remodeling after PIs. We then aim to extend our promising preliminary data demonstrating the efficacy of splicing inhibitors as a new anti-myeloma therapy. Overall, the studies here will have a direct impact on delineating the surprisingly broad range of PI-mediated effects in plasma cells, validate the novel therapeutic strategy of splicing inhibition, and reveal new mechanistic approaches to dissect proteostasis networks and alternative splicing that could extend far beyond myeloma.

项目总结/文摘