Protein Kinase CK2 Protects Multiple Myeloma Cells from ER Stress–Induced Apoptosis and from the Cytotoxic Effect of HSP90 Inhibition through Regulation of the Unfolded Protein Response
| Autor: | Alessandra Brancalion, Giovanni Di Maira, Maria Ruzzene, Anna Colpo, Fausto Adami, Carmela Gurrieri, Gianpietro Semenzato, Sabrina Manni, Francesco Piazza, Laura Quotti Tubi, Laura Pavan, Maria Rita Pitari, Anna Cabrelle, Lorenzo A. Pinna, Renato Zambello, Pierfrancesco Tassone, Fortunato Zaffino, Elisa Ave |
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| Rok vydání: | 2012 |
| Předmět: |
Cancer Research
animal structures Lactams Macrocyclic Blotting Western Apoptosis Mice SCID Mice Cell Line Tumor Benzoquinones Animals Humans HSP90 Heat-Shock Proteins Enzyme Inhibitors Kinase activity Casein Kinase II Endoplasmic Reticulum Chaperone BiP Cells Cultured Microscopy Confocal biology Reverse Transcriptase Polymerase Chain Reaction Cell growth Endoplasmic reticulum fungi Endoplasmic Reticulum Stress Xenograft Model Antitumor Assays Hsp90 Cell biology Gene Expression Regulation Neoplastic Oncology CDC37 embryonic structures Unfolded Protein Response Unfolded protein response Cancer research biology.protein Thapsigargin Phosphorylation RNA Interference Signal transduction Multiple Myeloma Signal Transduction |
| Zdroj: | Clinical Cancer Research. 18:1888-1900 |
| ISSN: | 1557-3265 1078-0432 |
| DOI: | 10.1158/1078-0432.ccr-11-1789 |
| Popis: | Purpose: Protein kinase CK2 promotes multiple myeloma cell growth by regulating critical signaling pathways. CK2 also modulates proper HSP90-dependent client protein folding and maturation by phosphorylating its co-chaperone CDC37. Because the endoplasmic reticulum (ER) stress/unfolded protein response (UPR) is central in myeloma pathogenesis, we tested the hypothesis that the CK2/CDC37/HSP90 axis could be involved in UPR in myeloma cells. Experimental Design: We analyzed CK2 activity upon ER stress, the effects of its inactivation on the UPR pathways and on ER stress–induced apoptosis. The consequences of CK2 plus HSP90 inhibition on myeloma cell growth in vitro and in vivo and CK2 regulation of HSP90-triggered UPR were determined. Results: CK2 partly localized to the ER and ER stress triggered its kinase activity. CK2 inhibition reduced the levels of the ER stress sensors IRE1α and BIP/GRP78, increased phosphorylation of PERK and EIF2α, and enhanced ER stress–induced apoptosis. Simultaneous inactivation of CK2 and HSP90 resulted in a synergic anti-myeloma effect (combination index = 0.291) and in much stronger alterations of the UPR pathways as compared with the single inhibition of the two molecules. Cytotoxicity from HSP90 and CK2 targeting was present in a myeloma microenvironment model, on plasma cells from patients with myeloma and in an in vivo mouse xenograft model. Mechanistically, CK2 inhibition led to a reduction of IRE1α/HSP90/CDC37 complexes in multiple myeloma cells. Conclusions: Our results place CK2 as a novel regulator of the ER stress/UPR cascades and HSP90 function in myeloma cells and offer the groundwork to design novel combination treatments for this disease. Clin Cancer Res; 18(7); 1888–900. ©2012 AACR. |
| Databáze: | OpenAIRE |
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