PT - JOURNAL ARTICLE AU - Lin, Yu-Hsiu T. AU - Way, Gregory P. AU - Barwick, Benjamin G. AU - Mariano, Margarette C. AU - Marcoulis, Makeba AU - Ferguson, Ian D. AU - Driessen, Christoph AU - Boise, Lawrence H. AU - Greene, Casey S. AU - Wiita, Arun P. TI - Integrated Phosphoproteomics and Transcriptional Classifiers Reveal Hidden RAS Signaling Dynamics in Multiple Myeloma AID - 10.1101/563312 DP - 2019 Jan 01 TA - bioRxiv PG - 563312 4099 - http://biorxiv.org/content/early/2019/02/28/563312.short 4100 - http://biorxiv.org/content/early/2019/02/28/563312.full AB - A major driver of multiple myeloma is thought to be aberrant signaling, yet no kinase inhibitors have proven successful in the clinic. Here, we employ an integrated, systems approach combining phosphoproteomic and transcriptome analysis to dissect cellular signaling in multiple myeloma to inform precision medicine strategies. Collectively, these predictive models identify vulnerable signaling signatures and highlight surprising differences in functional signaling patterns between NRAS and KRAS mutants invisible to the genomic landscape. Transcriptional analysis suggests that aberrant MAPK pathway activation is only present in a fraction of RAS-mutated vs. WT RAS patients. These high-MAPK patients, enriched for NRAS Q61 mutations, have inferior outcomes whereas RAS mutations overall carry no survival impact. We further develop an interactive software tool to relate pharmacologic and genetic kinase dependencies in myeloma. These results may lead to improved stratification of MM patients in clinical trials while also revealing unexplored modes of Ras biology.