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Murgai M, Thomas J, Cherepanova O, Delviks-Frankenberry K, Deeble P, Pathak VK, Rekosh D, Owens G. Xenotropic MLV envelope proteins induce tumor cells to secrete factors that promote the formation of immature blood vessels. Retrovirology 2013; 10:34. [PMID: 23537062 PMCID: PMC3681559 DOI: 10.1186/1742-4690-10-34] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 03/07/2013] [Indexed: 12/20/2022] Open
Abstract
Background Xenotropic Murine leukemia virus-Related Virus (XMRV) is a γ-retrovirus initially reported to be present within familial human prostate tumors and the blood of patients with chronic fatigue syndrome. Subsequent studies however were unable to replicate these findings, and there is now compelling evidence that the virus evolved through rare retroviral recombination events in human tumor cell lines established through murine xenograft experiments. There is also no direct evidence that XMRV infection has any functional effects that contribute to tumor pathogenesis. Results Herein we describe an additional xenotropic MLV, “B4rv”, found in a cell line derived from xenograft experiments with the human prostate cancer LNCaP cell line. When injected subcutaneously in nude mice, LNCaP cells infected with XMRV or B4rv formed larger tumors that were highly hemorrhagic and displayed poor pericyte/smooth muscle cell (SMC) investment, markers of increased metastatic potential. Conditioned media derived from XMRV- or B4rv-infected LNCaPs, but not an amphotropic MLV control virus infected LNCaPs, profoundly decreased expression of marker genes in cultured SMC, consistent with inhibition of SMC differentiation/maturation. Similar effects were seen with a chimeric virus of the amphotropic MLV control virus containing the XMRV env gene, but not with an XMRV chimeric virus containing the amphotropic MLV env gene. UV-inactivated XMRV and pseudovirions that were pseudotyped with XMRV envelope protein also produce conditioned media that down-regulated SMC marker gene expression in vitro. Conclusions Together these results indicate that xenotropic MLV envelope proteins are sufficient to induce the production of factors by tumor cells that suppress vascular SMC differentiation, providing evidence for a novel mechanism by which xenotropic MLVs might alter tumor pathogenesis by disrupting tumor vascular maturation. Although it is highly unlikely that either XMRV or B4Rv themselves infect humans and are pathogenic, the results suggest that xenograft approaches commonly used in the study of human cancer promote the evolution of novel retroviruses with pathogenic properties.
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Affiliation(s)
- Meera Murgai
- Robert M, Berne Cardiovascular Research Center, University of Virginia, School of Medicine Charlottesville, Charlottesville, VA 22908, USA
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Zhou ZH, Kumari N, Catalano J, Nekhai S, Wise J, Yamada KM, Dhawan S. Heme oxygenase-1-mediated host cell response inhibits the susceptibility of prostate cancer cells to retroviral infection and retards their proliferation. CURRENT TRENDS IN IMMUNOLOGY 2013; 14:53-56. [PMID: 25620854 PMCID: PMC4302767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Xenotropic murine leukemia virus-related virus (XMRV) resembles endogenous murine leukemia virus and was used in this study as a model for a new retrovirus infecting human cells. We demonstrate that induction of an HO-1-mediated host cell response inhibited the susceptibility of LNCaP prostate cancer cells to XMRV infection and efficiently retarded the growth of these prostate cancer cells. Our studies delineate a role of HO-1 in the host defense against retroviral infections and may provide novel therapeutic strategies for the treatment of HO-1-sensitive prostate cancer.
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Affiliation(s)
- Zhao-Hua Zhou
- Division of Monoclonal Antibodies, Center for Drug Evaluation and Research, Food and Drug Administration, Bethesda, MD
| | - Namita Kumari
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, DC
| | - Jennifer Catalano
- Division of Cellular and Gene Therapy, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD
| | - Sergei Nekhai
- Center for Sickle Cell Disease, Department of Medicine, Howard University, Washington, DC
| | | | - Kenneth M. Yamada
- Laboratory of Cell and Development Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - Subhash Dhawan
- Laboratory of Molecular Virology, Division of Emerging and Transfusion Transmitted Diseases, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD
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Lee D, Das Gupta J, Gaughan C, Steffen I, Tang N, Luk KC, Qiu X, Urisman A, Fischer N, Molinaro R, Broz M, Schochetman G, Klein EA, Ganem D, DeRisi JL, Simmons G, Hackett J, Silverman RH, Chiu CY. In-depth investigation of archival and prospectively collected samples reveals no evidence for XMRV infection in prostate cancer. PLoS One 2012; 7:e44954. [PMID: 23028701 PMCID: PMC3445615 DOI: 10.1371/journal.pone.0044954] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Accepted: 08/10/2012] [Indexed: 12/31/2022] Open
Abstract
XMRV, or xenotropic murine leukemia virus (MLV)-related virus, is a novel gammaretrovirus originally identified in studies that analyzed tissue from prostate cancer patients in 2006 and blood from patients with chronic fatigue syndrome (CFS) in 2009. However, a large number of subsequent studies failed to confirm a link between XMRV infection and CFS or prostate cancer. On the contrary, recent evidence indicates that XMRV is a contaminant originating from the recombination of two mouse endogenous retroviruses during passaging of a prostate tumor xenograft (CWR22) in mice, generating laboratory-derived cell lines that are XMRV-infected. To confirm or refute an association between XMRV and prostate cancer, we analyzed prostate cancer tissues and plasma from a prospectively collected cohort of 39 patients as well as archival RNA and prostate tissue from the original 2006 study. Despite comprehensive microarray, PCR, FISH, and serological testing, XMRV was not detected in any of the newly collected samples or in archival tissue, although archival RNA remained XMRV-positive. Notably, archival VP62 prostate tissue, from which the prototype XMRV strain was derived, tested negative for XMRV on re-analysis. Analysis of viral genomic and human mitochondrial sequences revealed that all previously characterized XMRV strains are identical and that the archival RNA had been contaminated by an XMRV-infected laboratory cell line. These findings reveal no association between XMRV and prostate cancer, and underscore the conclusion that XMRV is not a naturally acquired human infection.
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Affiliation(s)
- Deanna Lee
- Department of Laboratory Medicine, University of San Francisco, San Francisco, California, United States of America
- University of California San Francisco-Abbott Viral Diagnostics and Discovery Center, University of California San Francisco, San Francisco, California, United States of America
| | | | | | - Imke Steffen
- Blood Systems Research Institute, San Francisco, California, United States of America
| | - Ning Tang
- Abbott Laboratories, Abbott Park, Illinois, United States of America
| | - Ka-Cheung Luk
- Abbott Laboratories, Abbott Park, Illinois, United States of America
| | - Xiaoxing Qiu
- Abbott Laboratories, Abbott Park, Illinois, United States of America
| | - Anatoly Urisman
- Department of Laboratory Medicine, University of San Francisco, San Francisco, California, United States of America
| | - Nicole Fischer
- University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ross Molinaro
- Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Miranda Broz
- Department of Laboratory Medicine, University of San Francisco, San Francisco, California, United States of America
| | | | - Eric A. Klein
- Cleveland Clinic, Cleveland, Ohio, United States of America
| | - Don Ganem
- Novartis Institutes for Biomedical Research, Emeryville, California, United States of America
| | - Joseph L. DeRisi
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Graham Simmons
- Blood Systems Research Institute, San Francisco, California, United States of America
| | - John Hackett
- Abbott Laboratories, Abbott Park, Illinois, United States of America
| | | | - Charles Y. Chiu
- Department of Laboratory Medicine, University of San Francisco, San Francisco, California, United States of America
- University of California San Francisco-Abbott Viral Diagnostics and Discovery Center, University of California San Francisco, San Francisco, California, United States of America
- Department of Medicine, Division of Infectious Diseases, University of California San Francisco, San Francisco, California, United States of America
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Membrane fusion and cell entry of XMRV are pH-independent and modulated by the envelope glycoprotein's cytoplasmic tail. PLoS One 2012; 7:e33734. [PMID: 22479434 PMCID: PMC3313918 DOI: 10.1371/journal.pone.0033734] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Accepted: 02/16/2012] [Indexed: 11/19/2022] Open
Abstract
Xenotropic murine leukemia virus-related virus (XMRV) is a gammaretrovirus that was originally identified from human prostate cancer patients and subsequently linked to chronic fatigue syndrome. Recent studies showed that XMRV is a recombinant mouse retrovirus; hence, its association with human diseases has become questionable. Here, we demonstrated that XMRV envelope (Env)-mediated pseudoviral infection is not blocked by lysosomotropic agents and cellular protease inhibitors, suggesting that XMRV entry is not pH-dependent. The full length XMRV Env was unable to induce syncytia formation and cell-cell fusion, even in cells overexpressing the viral receptor, XPR1. However, truncation of the C-terminal 21 or 33 amino acid residues in the cytoplasmic tail (CT) of XMRV Env induced substantial membrane fusion, not only in the permissive 293 cells but also in the nonpermissive CHO cells that lack a functional XPR1 receptor. The increased fusion activities of these truncations correlated with their enhanced SU shedding into culture media, suggesting conformational changes in the ectodomain of XMRV Env. Noticeably, further truncation of the CT of XMRV Env proximal to the membrane-spanning domain severely impaired the Env fusogenicity, as well as dramatically decreased the Env incorporations into MoMLV oncoretroviral and HIV-1 lentiviral vectors resulting in greatly reduced viral transductions. Collectively, our studies reveal that XMRV entry does not require a low pH or low pH-dependent host proteases, and that the cytoplasmic tail of XMRV Env critically modulates membrane fusion and cell entry. Our data also imply that additional cellular factors besides XPR1 are likely to be involved in XMRV entry.
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Mohan KVK, Devadas K, Sainath Rao S, Hewlett I, Atreya C. Identification of XMRV infection-associated microRNAs in four cell types in culture. PLoS One 2012; 7:e32853. [PMID: 22438885 PMCID: PMC3306368 DOI: 10.1371/journal.pone.0032853] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 01/31/2012] [Indexed: 01/09/2023] Open
Abstract
INTRODUCTION XMRV is a gammaretrovirus that was thought to be associated with prostate cancer (PC) and chronic fatigue syndrome (CFS) in humans until recently. The virus is culturable in various cells of human origin like the lymphocytes, NK cells, neuronal cells, and prostate cell lines. MicroRNAs (miRNA), which regulate gene expression, were so far not identified in cells infected with XMRV in culture. METHODS Two prostate cell lines (LNCaP and DU145) and two primary cells, Peripheral Blood Lymphocytes [PBL] and Monocyte-derived Macrophages [MDM] were infected with XMRV. Total mRNA was extracted from mock- and virus-infected cells at 6, 24 and 48 hours post infection and evaluated for microRNA profile in a microarray. RESULTS MicroRNA expression profiles of XMRV-infected continuous prostate cancer cell lines differ from that of virus-infected primary cells (PBL and MDMs). miR-193a-3p and miRPlus-E1245 observed to be specific to XMRV infection in all 4 cell types. While miR-193a-3p levels were down regulated miRPlus-E1245 on the other hand exhibited varied expression profile between the 4 cell types. DISCUSSION The present study clearly demonstrates that cellular microRNAs are expressed during XMRV infection of human cells and this is the first report demonstrating the regulation of miR193a-3p and miRPlus-E1245 during XMRV infection in four different human cell types.
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Affiliation(s)
- Ketha V. K. Mohan
- Section of Cell Biology, Laboratory of Cellular Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Krishnakumar Devadas
- Laboratory of Molecular Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Shilpakala Sainath Rao
- Section of Cell Biology, Laboratory of Cellular Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Indira Hewlett
- Laboratory of Molecular Virology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
| | - Chintamani Atreya
- Section of Cell Biology, Laboratory of Cellular Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America
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