Proteomic signature of neuroblastoma cells UKF-NB-4 reveals key role of lysosomal sequestration and the proteasome complex in acquiring chemoresistance to cisplatin

28 p.-6 fig.Cisplatin (CDDP) is a widely used agent in the treatment of neuroblastoma. Unfortunately, the development of acquired chemoresistance limits its clinical use. To gain a detailed understanding of the mechanisms underlying the development of such chemoresistance, we comparatively analysed established cisplatin-resistant neuroblastoma cell line (UKF-NB-4CDDP) and its sensitive counterpart (UKF-NB-4). First, using viability screenings, we confirmed the decreased sensitivity of tested cells to cisplatin and identified a cross-resistance to carboplatin and oxaliplatin. Then, the proteomic signatures were analysed using nanoLC MS/MS. Among the proteins responsible for UKF-NB-4CDDP chemoresistance, ion channels transport family proteins, ABC superfamily proteins, SLC-mediated trans-membrane transporters, proteasome complex subunits and V-ATPases were identified. Moreover, we detected markedly higher proteasome activity in UKF-NB-4CDDP cells and a remarkable lysosomal enrichment that can be inhibited by bafilomycin A to sensitize UKF-NB-4CDDP to CDDP. Our results indicate that lysosomal sequestration and proteasome activity may be one of key mechanisms responsible for intrinsic chemoresistance of neuroblastoma to CDDP.This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No.759585). The authors also gratefully acknowledge financial support from AZV project 15-28334A, ERASMUS + Staff Mobility from European Commission and from the Ministry of Health of the Czech Republic for conceptual development of research organization 00064203 17(University Hospital Motol, Prague, Czech Republic).Peer reviewe