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Multiple Myeloma, Gammopathies

Mitochondrial thioredoxin reductase regulates major cytotoxicity pathways of proteasome inhibitors in multiple myeloma cells


It is generally accepted that intracellular oxidative stress induced by proteasome inhibitors is a byproduct of endoplasmic reticulum (ER) stress. Here we report a mechanism underlying the ability of proteasome inhibitors bortezomib (BTZ) and carfilzomib (CFZ) to directly induce oxidative and ER stresses in multiple myeloma (MM) cells via transcriptional repression of a gene encoding mitochondrial thioredoxin reductase (TXNRD2). TXNRD2 is critical for maintenance of intracellular red–ox status and detoxification of reactive oxygen species. Depletion of TXNRD2 to the levels detected in BTZ- or CFZ-treated cells causes oxidative stress, ER stress and death similar to those induced by proteasome inhibitors. Reciprocally, restoration of near-wildtype TXNRD2 amounts in MM cells treated with proteasome inhibitors reduces oxidative stress, ER stress and cell death by ~46%, ~35% and ~50%, respectively, compared with cells with unrestored TXNRD2 levels. Moreover, cells from three MM cell lines selected for resistance to BTZ demonstrate elevated levels of TXNRD2, indirectly confirming its functional role in BTZ resistance. Accordingly, ectopic expression of TXNRD2 in MM cell xenografts in immunocompromised mice blunts therapeutic effects of BTZ. Our data identify TXNRD2 as a potentially clinically relevant target, inhibition of which is critical for proteasome inhibitor-dependent cytotoxicity, oxidative stress and ER stress.

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  1. Anderson KC . Bortezomib therapy for myeloma. Curr Hematol Rep 2004; 3: 65.

    PubMed  Google Scholar 

  2. Greenlee RT, Murray T, Bolden S, Wingo PA . Cancer statistics, 2000. CA Cancer J Clin 2000; 50: 7–33.

    Article  CAS  Google Scholar 

  3. Kumar SK, Rajkumar SV, Dispenzieri A, Lacy MQ, Hayman SR, Buadi FK et al. Improved survival in multiple myeloma and the impact of novel therapies. Blood 2008; 111: 2516–2520.

    Article  CAS  Google Scholar 

  4. Raab MS, Podar K, Breitkreutz I, Richardson PG, Anderson KC . Multiple myeloma. Lancet 2009; 374: 324–339.

    Article  Google Scholar 

  5. Venner CP, Connors JM, Sutherland HJ, Shepherd JD, Hamata L, Mourad YA et al. Novel agents improve survival of transplant patients with multiple myeloma including those with high-risk disease defined by early relapse (< 12 months). Leuk Lymphoma 2011; 52: 34–41.

    Article  CAS  Google Scholar 

  6. Herndon TM, Deisseroth A, Kaminskas E, Kane RC, Koti KM, Rothmann MD et al. U.S. Food and Drug Administration Approval: Carfilzomib for the Treatment of Multiple Myeloma. Clin Cancer Res 2013; 19: 4559–4563.

    Article  CAS  Google Scholar 

  7. Demo SD, Kirk CJ, Aujay MA, Buchholz TJ, Dajee M, Ho MN et al. Antitumor activity of PR-171, a novel irreversible inhibitor of the proteasome. Cancer Res 2007; 67: 6383–6391.

    Article  CAS  Google Scholar 

  8. Kuhn DJ, Chen Q, Voorhees PM, Strader JS, Shenk KD, Sun CM et al. Potent activity of carfilzomib, a novel, irreversible inhibitor of the ubiquitin-proteasome pathway, against preclinical models of multiple myeloma. Blood 2007; 110: 3281–3290.

    Article  CAS  Google Scholar 

  9. Parlati F, Lee S, Aujay M, Levitsky K, Lorens J, Lu Y et al. Carfilzomib: a selective inhibitor of the chymotrypsin-like activity of the constitutive proteasome and immunoproteasome has anti-tumor activity on multiple myeloma, lymphoma, and leukemia cells with minimal effects on normal cells. Haematologica 2009; 94: 0373.

    Google Scholar 

  10. Obeng EA, Carlson LM, Gutman DM, Harrington WJ Jr, Lee KP, Boise LH . Proteasome inhibitors induce a terminal unfolded protein response in multiple myeloma cells. Blood 2006; 107: 4907–4916.

    Article  CAS  Google Scholar 

  11. Tabas I, Ron D . Integrating the Mechanisms of Apoptosis Induced by Endoplasmic Reticulum Stress. Nat Cell Biol 2011; 13: 184–190.

    Article  CAS  Google Scholar 

  12. Finkel T, Holbrook NJ . Oxidants, oxidative stress and the biology of ageing. Nature 2000; 408: 239–247.

    Article  CAS  Google Scholar 

  13. Hileman EO, Liu J, Albitar M, Keating MJ, Huang P . Intrinsic Oxidative stress in cancer cells: a biochemical basis for therapeutic selectivity. Cancer Chemother Pharmacol 2004; 53: 209–219.

    Article  CAS  Google Scholar 

  14. Toyokuni S, Okamoto K, Yodoi J, Hiai H . Persistent Oxidative stress in Cancer. FEBS Letters 1995; 358: 1–3.

    Article  CAS  Google Scholar 

  15. Schumacker PT . Reactive Oxygen species in cancer cells: live by the sword, die by the sword. Cancer Cell 2006; 10: 175–176.

    CAS  Google Scholar 

  16. Ling YH, Liebes L, Zou Y, Perez-Soler R . Reactive oxygen species generation and mitochondrial dysfunction in the apoptotic response to Bortezomib, a novel proteasome inhibitor, in human H460 non-small cell lung cancer cells. J Biol Chem 2003; 278: 33714–33723.

    Article  CAS  Google Scholar 

  17. Du ZX, Zhang HY, Meng X, Guan Y, Wang HQ . Role of oxidative stress and intracellular glutathione in the sensitivity to apoptosis induced by proteasome inhibitor in thyroid cancer cells. BMC Cancer 2009; 9: 56.

    Article  Google Scholar 

  18. Weniger MA, Rizzatti EG, Perez-Galan P, Liu D, Wang Q, Munson PJ et al. Treatment-Induced Oxidative Stress and Cellular Antioxidant Capacity Determine Response to Bortezomib in Mantle Cell Lymphoma. Clin Cancer Res 2011; 17: 5102–5112.

    Article  Google Scholar 

  19. Fribley A, Zeng Q, Wang CY . Proteasome inhibitor PS-341 induces apoptosis through induction of endoplasmic reticulum stress-reactive oxygen species in head and neck squamous cell carcinoma cells. Mol Cell Biol 2004; 24: 9695–9704.

    Article  CAS  Google Scholar 

  20. Bhandary B, Marahatta A, Kim HR, Chae HJ . An involvement of oxidative stress in endoplasmic reticulum stress and its associated diseases. Int J Mol Sci 2012; 14: 434–456.

    Article  Google Scholar 

  21. Yu C, Rahmani M, Dent P, Grant S . The hierarchical relationship between MAPK signaling and ROS generation in human leukemia cells undergoing apoptosis in response to the proteasome inhibitor Bortezomib. Exp Cell Res 2004; 295: 555–566.

    Article  CAS  Google Scholar 

  22. Mannava S, Zhuang D, Nair JR, Bansal R, Wawrzyniak JA, Zucker SN et al. KLF9 is a novel transcriptional regulator of bortezomib- and LBH589-induced apoptosis in multiple myeloma cells. Blood 2012; 119: 1450–1458.

    Article  CAS  Google Scholar 

  23. Zucker SN, Fink EE, Bagati A, Mannava S, Bianchi-Smiraglia A, Bogner PN et al. Nrf2 Amplifies Oxidative Stress via Induction of Klf9. Molecular Cell 2014; 53: 916–928.

    Article  CAS  Google Scholar 

  24. Arnér ES . Focus on mammalian thioredoxin reductases—important selenoproteins with versatile functions. Biochim Biophys Acta 2009; 1790: 495–526.

    Article  Google Scholar 

  25. Horstkotte J, Perisic T, Schneider M, Lange P, Schroeder M, Kiermayer C et al. Mitochondrial thioredoxin reductase is essential for early postischemic myocardial protection. Circulation 2011; 124: 2892–2902.

    Article  CAS  Google Scholar 

  26. Kuhn DJ, Berkova Z, Jones RJ, Woessner R, Bjorklund CC, Ma W, Davis RE et al. Targeting the insulin-like growth factor-1 receptor to overcome bortezomib resistance in preclinical models of multiple myeloma. Blood 2012; 120: 3260–3270.

    Article  CAS  Google Scholar 

  27. Gado K, Silvia S, Paloczi K . Mouse Plasmacytoma: an experimental model of human multiple myeloma. Haematologica 2001; 86: 227–236.

    CAS  PubMed  Google Scholar 

  28. Arnér ESJ, Holmgren A . Physiological functions of thioredoxin and thioredoxin reductase. Eur J Biochem 2000; 267: 6102–6109.

    Article  Google Scholar 

  29. Fernández Y, Verhaegen M, Miller TP, Rush JL, Steiner P, Opipari AW Jr et al. Differential regulation of noxa in normal melanocytes and melanoma cells by proteasome inhibition: therapeutic implications. Cancer Res 2005; 65: 6294–6304.

    Article  Google Scholar 

  30. Minami T, Adachi M, Kawamura R . Sulindac Enhances the Proteasome Inhibitor Bortezomib-Mediated Oxidative Stress and Anticancer Activity. Clin Cancer Res 2005; 11: 5248–5256.

    Article  CAS  Google Scholar 

  31. Shringarpure R, Catley L, Bhole D, Burger R, Podar K, Tai YT et al. Gene expression analysis of B-lymphoma cells resistant and sensitive to bortezomib. Br J Haematol 2006; 134: 145–156.

    Article  CAS  Google Scholar 

  32. Chen L, Wang S, Zhou Y, Wu X, Entin I, Epstein J et al. Identification of early growth response protein 1 (EGR-1) as a novel target for JUN-induced apoptosis in multiple myeloma. Blood 2010; 115: 61–70.

    Article  CAS  Google Scholar 

  33. Hideshima T, Chauhan D, Richardson P, Mitsiades C, Mitsiades N, Hayashi T et al. NF-kappa B as a therapeutic target in multiple myeloma. J Biol Chem 2002; 277: 16639–16647.

    Article  CAS  Google Scholar 

  34. Philips R, Bibby M, Double J . A critical appraisal of the predictive value of in vitro chemosensitivity assays. J Natl Cancer Inst 1990; 82: 1457–1468.

    Article  Google Scholar 

  35. Michaelis M, Fichtner I, Behrens D, Haider W, Rothweiler F, Mack A et al. Anti-cancer effects of bortezomib against chemoresistant neuroblastoma cell lines in vitro and in vivo. Int. J. Oncol 2006; 28: 439–446.

    CAS  PubMed  Google Scholar 

  36. Malhorta JD, Kaufman RJ . Endoplasmic Reticulum Stress and Oxidative Stress: A Vicious Cycle or a Double-Edged Sword? Antioxid Redox Signal 2007; 9: 2277–2293.

    Article  Google Scholar 

  37. Verfaillie T, Rubio N, Garg AD, Bultynck G, Rizzuto R, Decuypere JP et al. PERK is required at the ER-mitochondrial contact sites to convey apoptosis after ROS-based ER stress. Cell Death Differ 2012; 19: 1880–1891.

    Article  CAS  Google Scholar 

  38. Tagawa Y, Hiramatsu N, Kasai A, Hayakawa K, Okamura M, Yao J et al. Induction of apoptosis by cigarette smoke via ROS-dependent endoplasmic reticulum stress and CCAAT/enhancer-binding protein-homologous protein (CHOP). Free Radic Biol Med 2008; 45: 50–59.

    Article  CAS  Google Scholar 

  39. Prince HM, Bishton MJ, Johnstone RW . Panobinostat (LBH589): a potent pan-deacetylase inhibitor with promising activity against hematologic and solid tumors. Future Oncol 2009; 5: 601–612.

    Article  CAS  Google Scholar 

  40. Shenp P, Sun J, Xu G, Zhang L, Yang Z, Xia S et al. KLF9, a transcription factor induced in flutamide-caused cell apoptosis, inhibits AKT activation and suppresses tumor growth of prostate cancer cells. Prostate 2014; 74: 946–958.

    Article  Google Scholar 

  41. Nakaya A, Sagawa M, Muto A, Uchida H, Ikeda Y, Kizaki M . The gold compound auranofin induces apoptosis of human multiple myeloma cells through both down-regulation of STAT3 and inhibition of NF-κB activity. Leuk Res 2011; 35: 243–249.

    Article  CAS  Google Scholar 

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We are grateful for Dr Dominic Smiraglia for critical reading of the manuscript. This work was supported by the following NCI grants: R01 CA120244 to M.A.N. and R01 CA121044 to K.P.L., T32 CA085183 to A.U., and Jennifer Linscott Tietgen Foundation to M.A.N.

Author contributions

EEF, SM, AB, AB-S and AU performed experiments; JRN, KPL, MD, VGS, LPM and MAN analyzed the results; MD, AU, LPM and MAN designed the research, EEF and MAN wrote the manuscript.

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Correspondence to M A Nikiforov.

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Fink, E., Mannava, S., Bagati, A. et al. Mitochondrial thioredoxin reductase regulates major cytotoxicity pathways of proteasome inhibitors in multiple myeloma cells. Leukemia 30, 104–111 (2016).

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