The Proteasome Deubiquitinase Inhibitor VLX1570 Shows Selectivity for Ubiquitin-specific Protease-14 and Induces Apoptosis of Multiple Myeloma Cells

Overview

Journal Sci Rep

Specialty Science

Date 2016 Jun 7

PMID 27264969

Citations 87

Authors

Xin Wang

Magdalena Mazurkiewicz

Ellin-Kristina Hillert

Maria Hagg Olofsson

Stefan Pierrou

Per Hillertz

Joachim Gullbo

Karthik Selvaraju

Aneel Paulus

Sharoon Akhtar

Felicitas Bossler

Asher Chanan Khan

Stig Linder

Padraig Darcy

Affiliations

Soon will be listed here.

Abstract

Inhibition of deubiquitinase (DUB) activity is a promising strategy for cancer therapy. VLX1570 is an inhibitor of proteasome DUB activity currently in clinical trials for relapsed multiple myeloma. Here we show that VLX1570 binds to and inhibits the activity of ubiquitin-specific protease-14 (USP14) in vitro, with comparatively weaker inhibitory activity towards UCHL5 (ubiquitin-C-terminal hydrolase-5). Exposure of multiple myeloma cells to VLX1570 resulted in thermostabilization of USP14 at therapeutically relevant concentrations. Transient knockdown of USP14 or UCHL5 expression by electroporation of siRNA reduced the viability of multiple myeloma cells. Treatment of multiple myeloma cells with VLX1570 induced the accumulation of proteasome-bound high molecular weight polyubiquitin conjugates and an apoptotic response. Sensitivity to VLX1570 was moderately affected by altered drug uptake, but was unaffected by overexpression of BCL2-family proteins or inhibitors of caspase activity. Finally, treatment with VLX1570 was found to lead to extended survival in xenograft models of multiple myeloma. Our findings demonstrate promising antiproliferative activity of VLX1570 in multiple myeloma, primarily associated with inhibition of USP14 activity.

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References

Wang X, Chen C, Baker P, Chen P, Kaiser P, Huang L . Mass spectrometric characterization of the affinity-purified human 26S proteasome complex. Biochemistry. 2007; 46(11):3553-65. DOI: 10.1021/bi061994u. View

GOLDBERG A . Functions of the proteasome: from protein degradation and immune surveillance to cancer therapy. Biochem Soc Trans. 2007; 35(Pt 1):12-7. DOI: 10.1042/BST0350012. View

Lee B, Lee M, Park S, Oh D, Elsasser S, Chen P . Enhancement of proteasome activity by a small-molecule inhibitor of USP14. Nature. 2010; 467(7312):179-84. PMC: 2939003. DOI: 10.1038/nature09299. View

Galluzzi L, Kroemer G . Necroptosis: a specialized pathway of programmed necrosis. Cell. 2008; 135(7):1161-3. DOI: 10.1016/j.cell.2008.12.004. View

Richardson P, Mitsiades C, Hideshima T, Anderson K . Proteasome inhibition in the treatment of cancer. Cell Cycle. 2005; 4(2):290-6. View

Hershko A, Ciechanover A . The ubiquitin system. Annu Rev Biochem. 1998; 67:425-79. DOI: 10.1146/annurev.biochem.67.1.425. View

Steinbrunn T, Chatterjee M, Bargou R, Stuhmer T . Efficient transient transfection of human multiple myeloma cells by electroporation--an appraisal. PLoS One. 2014; 9(6):e97443. PMC: 4047019. DOI: 10.1371/journal.pone.0097443. View

Jafari R, Almqvist H, Axelsson H, Ignatushchenko M, Lundback T, Nordlund P . The cellular thermal shift assay for evaluating drug target interactions in cells. Nat Protoc. 2014; 9(9):2100-22. DOI: 10.1038/nprot.2014.138. View

Molina D, Jafari R, Ignatushchenko M, Seki T, Larsson E, Dan C . Monitoring drug target engagement in cells and tissues using the cellular thermal shift assay. Science. 2013; 341(6141):84-7. DOI: 10.1126/science.1233606. View

10.

Tian Z, Darcy P, Wang X, Ray A, Tai Y, Hu Y . A novel small molecule inhibitor of deubiquitylating enzyme USP14 and UCHL5 induces apoptosis in multiple myeloma and overcomes bortezomib resistance. Blood. 2013; 123(5):706-16. PMC: 3907756. DOI: 10.1182/blood-2013-05-500033. View

11.

Lee M, Lee B, Hanna J, King R, Finley D . Trimming of ubiquitin chains by proteasome-associated deubiquitinating enzymes. Mol Cell Proteomics. 2010; 10(5):R110.003871. PMC: 3098602. DOI: 10.1074/mcp.R110.003871. View

12.

Borodovsky A, Kessler B, Casagrande R, Overkleeft H, Wilkinson K, Ploegh H . A novel active site-directed probe specific for deubiquitylating enzymes reveals proteasome association of USP14. EMBO J. 2001; 20(18):5187-96. PMC: 125629. DOI: 10.1093/emboj/20.18.5187. View

13.

Brnjic S, Mazurkiewicz M, Fryknas M, Sun C, Zhang X, Larsson R . Induction of tumor cell apoptosis by a proteasome deubiquitinase inhibitor is associated with oxidative stress. Antioxid Redox Signal. 2013; 21(17):2271-85. PMC: 4241954. DOI: 10.1089/ars.2013.5322. View

14.

Mullally J, Fitzpatrick F . Pharmacophore model for novel inhibitors of ubiquitin isopeptidases that induce p53-independent cell death. Mol Pharmacol. 2002; 62(2):351-8. DOI: 10.1124/mol.62.2.351. View

15.

Homma T, Ishibashi D, Nakagaki T, Fuse T, Mori T, Satoh K . Ubiquitin-specific protease 14 modulates degradation of cellular prion protein. Sci Rep. 2015; 5:11028. PMC: 4462021. DOI: 10.1038/srep11028. View

16.

Hamamura R, Ohyashiki J, Kurashina R, Kobayashi C, Zhang Y, Takaku T . Induction of heme oxygenase-1 by cobalt protoporphyrin enhances the antitumour effect of bortezomib in adult T-cell leukaemia cells. Br J Cancer. 2007; 97(8):1099-105. PMC: 2360455. DOI: 10.1038/sj.bjc.6604003. View

17.

Yao T, Song L, Xu W, DeMartino G, Florens L, Swanson S . Proteasome recruitment and activation of the Uch37 deubiquitinating enzyme by Adrm1. Nat Cell Biol. 2006; 8(9):994-1002. DOI: 10.1038/ncb1460. View

18.

Ritorto M, Ewan R, Perez-Oliva A, Knebel A, Buhrlage S, Wightman M . Screening of DUB activity and specificity by MALDI-TOF mass spectrometry. Nat Commun. 2014; 5:4763. PMC: 4147353. DOI: 10.1038/ncomms5763. View

19.

Chauhan D, Hideshima T, Mitsiades C, Richardson P, Anderson K . Proteasome inhibitor therapy in multiple myeloma. Mol Cancer Ther. 2005; 4(4):686-92. DOI: 10.1158/1535-7163.MCT-04-0338. View

20.

Anchoori R, Karanam B, Peng S, Wang J, Jiang R, Tanno T . A bis-benzylidine piperidone targeting proteasome ubiquitin receptor RPN13/ADRM1 as a therapy for cancer. Cancer Cell. 2013; 24(6):791-805. PMC: 3881268. DOI: 10.1016/j.ccr.2013.11.001. View