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Garant KA, Shmulevitz M, Pan L, Daigle RM, Ahn DG, Gujar SA, Lee PWK. Oncolytic reovirus induces intracellular redistribution of Ras to promote apoptosis and progeny virus release. Oncogene 2015; 35:771-82. [PMID: 25961930 DOI: 10.1038/onc.2015.136] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 02/13/2015] [Accepted: 03/27/2015] [Indexed: 11/09/2022]
Abstract
Reovirus is a naturally oncolytic virus that preferentially replicates in Ras-transformed cells and is currently undergoing clinical trials as a cancer therapeutic. Ras transformation promotes reovirus oncolysis by enhancing virion disassembly during entry, viral progeny production, and virus release through apoptosis; however, the mechanism behind the latter is not well understood. Here, we show that reovirus alters the intracellular location of oncogenic Ras to induce apoptosis of H-RasV12-transformed fibroblasts. Reovirus infection decreases Ras palmitoylation levels and causes accumulation of Ras in the Golgi through Golgi fragmentation. With the Golgi being the site of Ras palmitoylation, treatment of target cells with the palmitoylation inhibitor, 2-bromopalmitate (2BP), prompts a greater accumulation of H-RasV12 in the Golgi, and a dose-dependent increase in progeny virus release and subsequent spread. Conversely, tethering H-RasV12 to the plasma membrane (thereby preventing its movement to the Golgi) allows for efficient virus production, but results in basal levels of reovirus-induced cell death. Analysis of Ras downstream signaling reveals that cells expressing cycling H-RasV12 have elevated levels of phosphorylated JNK (c-Jun N-terminal kinase), and that Ras retained at the Golgi body by 2BP increases activation of the MEKK1/MKK4/JNK signaling pathway to promote cell death. Collectively, our data suggest that reovirus induces Golgi fragmentation of target cells, and the subsequent accumulation of oncogenic Ras in the Golgi body initiates apoptotic signaling events required for virus release and spread.
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Affiliation(s)
- K A Garant
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - M Shmulevitz
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - L Pan
- Division of Fundamental Neurobiology, Toronto Western Research Institute, Toronto, ON, Canada
| | - R M Daigle
- Department of Oceanography, Dalhousie University, Halifax, NS, Canada
| | - D-G Ahn
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada
| | - S A Gujar
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada.,Strategy and Organizational Performance, IWK Health Centre, Halifax, NS, Canada
| | - P W K Lee
- Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada.,Department of Pathology, Dalhousie University, Halifax, NS, Canada
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Garamszegi N, Garamszegi SP, Scully SP. Matrix metalloproteinase-1 contribution to sarcoma cell invasion. J Cell Mol Med 2012; 16:1331-41. [PMID: 21801306 PMCID: PMC3823085 DOI: 10.1111/j.1582-4934.2011.01402.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Matrix metalloproteinase-1 (MMP-1) activity has been linked to numerous disease processes from arthritis to ulcer. Its proteolytic activity has been implicated inconsistently in different steps of tumourigenesis and metastasis. The discrepancies may be attributable to our limited understanding of MMP-1 production, cellular trafficking, secretion and local activation. Specifically, regulation of MMP-1 directional delivery versus its general extracellular matrix secretion is largely unknown. Inhibition of prenylation by farnesyl transferase inhibitor (FTI-276) decreased extracellular MMP-1 and subsequently reduced invasiveness by 30%. Parallel, stable cell line RNAi knockdown of MMP-1 confirmed its role in cellular invasiveness. The prenylation agonist farnesyl pyrophosphate (FPP) partially normalized FTI-276 inhibited extracellular MMP-1 levels and invasion capacity while transiently delayed its cellular podia distribution. MMP-1 directional delivery to these structures were confirmed by combination of a MMP-1–specific fluorogenic substrate, a MMP1-Ds-Red fusion protein construct expression and DQ-collagen degradation, which demonstrated coupling of directional delivery and activation. MetaMorph analysis of cellular lamellipodia structures indicated that FTI-276 inhibited formation and delivery to these structures. Farnesyl pyrophosphate partially restored lamellipodia area but not MMP-1 delivery under the time frame investigated. These results indicate that MMP-1 directional delivery to podia structures is involved in the invasive activity of sarcoma cells, and this process is prenylation sensitive.
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Affiliation(s)
- Nandor Garamszegi
- Sarcoma Biology Laboratory of Sylvester Comprehensive Cancer Center, University of Miami, Miller School of Medicine, FL, USA.
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Wong WWL, Clendening JW, Martirosyan A, Boutros PC, Bros C, Khosravi F, Jurisica I, Stewart AK, Bergsagel PL, Penn LZ. Determinants of sensitivity to lovastatin-induced apoptosis in multiple myeloma. Mol Cancer Ther 2007; 6:1886-97. [PMID: 17575117 DOI: 10.1158/1535-7163.mct-06-0745] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Statins, commonly used to treat hypercholesterolemia, have been shown to trigger tumor-specific apoptosis in certain cancers, including multiple myeloma (MM), a plasma cell malignancy with poor prognosis. In this article, we show that of a panel of 17 genetically distinct MM cell lines, half were sensitive to statin-induced apoptosis and, despite pharmacodynamic evidence of drug uptake and activity, the remainder were insensitive. Sensitive cells were rescued from lovastatin-induced apoptosis by mevalonate, geranylgeranyl PPi, and partially by farnesyl PPi, highlighting the importance of isoprenylation. Expression profiling revealed that Rho GTPase mRNAs were differentially expressed upon lovastatin exposure in sensitive cells, yet ectopic expression of constitutively active Rho or Ras proteins was insufficient to alter sensitivity to lovastatin-induced apoptosis. This suggests that sensitivity involves more than one isoprenylated protein and that statins trigger apoptosis by blocking many signaling cascades, directly or indirectly deregulated by the oncogenic lesions of the tumor cell. Indeed, clustering on the basis of genetic abnormalities was shown to be significantly associated with sensitivity (P = 0.003). These results suggest that statins may be a useful molecular targeted therapy in the treatment of a subset of MM.
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Affiliation(s)
- W Wei-Lynn Wong
- Departments of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
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Goldfinger LE, Ptak C, Jeffery ED, Shabanowitz J, Han J, Haling JR, Sherman NE, Fox JW, Hunt DF, Ginsberg MH. An experimentally derived database of candidate Ras-interacting proteins. J Proteome Res 2007; 6:1806-11. [PMID: 17439166 PMCID: PMC4627692 DOI: 10.1021/pr060630l] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We used a TAP-tag approach to identify candidate binding proteins for the related Ras family GTPases: H-Ras, R-Ras, and Rap1A. Protein complexes were isolated from mouse fibroblasts, and component proteins were identified by a combination of nanoflow HPLC and tandem mass spectrometry. H-Ras was found to associate with numerous cytoskeletal proteins including talin-1. R-Ras and Rap1A each associated with various signaling molecules, many of which are membrane-associated. Thus, we have established the first database of potential Ras interactors in mammalian cells.
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Affiliation(s)
- Lawrence E Goldfinger
- Division of Rheumatology, Department of Medicine, University of California, San Diego, La Jolla, California 92093, USA.
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