Mayo Clinic Center for Clinical Proteomics - PROJECT SUMMARY/ABSTRACT We propose to create a multidisciplinary Mayo Clinic Center for Clinical Proteomics with the overarching goal of identifying and validating proteomic biomarkers for treatment response in multiple myeloma. This center is a unique alliance comprising of two teams within the Mayo Clinic umbrella and one team at Brigham Young University. This team of physicians and scientists at Mayo Clinic with expertise in multiple myeloma diagnosis, treatment, clinical trials and basic research as well as technologies such as mass spectrometry, genomics, transcriptomics, bioinformatics and clinical assay development will be joined by a world expert in novel instrument/platform development at Brigham Young University to create a unique center. Multiple myeloma is a complex disease with several distinct cytogenetic subtypes. A recently developed class of drugs designated immunomodulatory imide drugs (IMiDs) has become a mainstay of treatment of multiple myeloma although relapses among patients is high mainly due to drug resistance. The primary target of IMiDs is cereblon (CRBN), which is absolutely required for its anti-cancer and immune activity. IMiDs activate the enzymatic activity of the CRBN E3 ubiquitin ligase complex leading to ubiquitylation and degradation of transcription factors IKZF1 and IKZF3, thereby regulating tumor survival and immune response through downregulation of IRF4 and MYC. For the preclinical arm, our interdisciplinary team will undertake discovery studies involving comprehensive proteogenomic characterization (proteome, phosphoproteome, ubiquitylome, genome, transcriptome) of multiple myeloma models (genetically engineered cell lines, humanized mouse models and patient samples) to identify molecular markers of IMiD resistance. Given the centrality of CRBN-mediated pathways in IMiD resistance, we will jumpstart our targeted proteomics efforts by focusing on developing targeted assays for CRBN and its downstream effectors. In parallel, we anticipate identifying additional candidate proteins through our discovery studies, for which targeted assays will also be developed. Finally, Dr. Vincent Rajkumar, a co-investigator on this proposal, will provide access to samples from three NCI-sponsored clinical trials specifically designed to look at effects of IMiDs enabling validation of candidates through a targeted approach. By incorporating continuous development of multiple technology platforms including CyTOF, we will ensure that we maintain agility over the duration of the proposal. With an established advanced infrastructure, personnel experienced in the development of CAP/CLIA assays, dedicated instrumentation, high analytical capacity and existing pipelines for QC, data handling and bioinformatics, the proposed Mayo Clinic Center for Clinical Proteomics is poised for success to discover and validate proteomic markers of IMiD resistance in multiple myeloma.