Comparative proteomic profiling of refractory/relapsed multiple myeloma reveals biomarkers involved in resistance to bortezomib-based therapy

// Dominik Dytfeld 1, 9, * , Magdalena Luczak 2, 11, * , Tomasz Wrobel 3, 9, Lidia Usnarska-Zubkiewicz 3 , Katarzyna Brzezniakiewicz 3, 9 , Krzysztof Jamroziak 5, 9 , Krzysztof Giannopoulos 6, 9 , Anna Przybylowicz-Chalecka 1 , Blazej Ratajczak 1 , Joanna Czerwinska-Rybak 1 , Adam Nowicki 1, 9 , Monika Joks 1, 9 , Elzbieta Czechowska 7, 9 , Magdalena Zawartko 8 , Tomasz Szczepaniak 1, 9 , Norbert Grzasko 6, 9 , Marta Morawska 6, 9 , Maciej Bochenek 1 , Tadeusz Kubicki 1 , Michalina Morawska 4, 9 , Katarzyna Tusznio 5 , Andrzej Jakubowiak 10 , Mieczyslaw Komarnicki 1 1 Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland 2 nstitute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland 3 Department of Hematology and Bone Marrow Transplantation, Wroclaw Medical University, Wroclaw, Poland 4 Department of Hematology, Hospital in Gorzow Wlkp, Gorzow Wlkp, Poland 5 Institute of Hematology and Transfusiology, Warsaw, Poland 6 Experimental Hematooncology Department, Medical University of Lublin and Hematology Department, St John's Cancer Center in Lublin, Lublin, Poland 7 Department of Internal Medicine and Hematology, Stanislaw Staszic Specialist Hospital, Pila, Poland 8 Department of Hematology, 109 Military Hospital, Szczecin, Poland 9 Researchers of Polish Myeloma Consortium 10 University of Chicago, Chicago, IL, USA 11 Institute of Chemical Technology and Engineering, Poznan University of Technology, Poznan, Poland * These authors contributed equally to this work Correspondence to: Dominik Dytfeld, email: dytfeld@icloud.com Keywords: multiple myeloma, bortezomib, label-free proteomics, iTRAQ, thioredoxin Received: June 08, 2016      Accepted: July 20, 2016      Published: August 04, 2016 ABSTRACT Identifying biomarkers of the resistance in multiple myeloma (MM) is a key research challenge. We aimed to identify proteins that differentiate plasma cells in patients with refractory/relapsed MM (RRMM) who achieved at least very good partial response (VGPR) and in those with reduced response to PAD chemotherapy (bortezomib, doxorubicin and dexamethasone). Comparative proteomic analysis was conducted on pretreatment plasma cells from 77 proteasome inhibitor naive patients treated subsequently with PAD due to RRMM. To increase data confidence we used two independent proteomic platforms: isobaric Tags for Relative and Absolute Quantitation (iTRAQ) and label free (LF). Proteins were considered as differentially expressed when their accumulation between groups differed by at least 50% in iTRAQ and LF. The proteomic signature revealed 118 proteins (35 up-regulated and 83 down-regulated in ≥ VGPR group). Proteins were classified into four classes: (1) involved in proteasome function; (2) involved in the response to oxidative stress; (3) related to defense response; and (4) regulating the apoptotic process. We confirmed the differential expression of proteasome activator complex subunit 1 (PSME1) by enzyme-linked immunosorbent assay. Increased expression of proteasomes and proteins involved in protection from oxidative stress (eg., TXN, TXNDC5) plays a major role in bortezomib resistance.