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Moens U, Passerini S, Falquet M, Sveinbjørnsson B, Pietropaolo V. Phosphorylation of Human Polyomavirus Large and Small T Antigens: An Ignored Research Field. Viruses 2023; 15:2235. [PMID: 38005912 PMCID: PMC10674619 DOI: 10.3390/v15112235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/02/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Protein phosphorylation and dephosphorylation are the most common post-translational modifications mediated by protein kinases and protein phosphatases, respectively. These reversible processes can modulate the function of the target protein, such as its activity, subcellular localization, stability, and interaction with other proteins. Phosphorylation of viral proteins plays an important role in the life cycle of a virus. In this review, we highlight biological implications of the phosphorylation of the monkey polyomavirus SV40 large T and small t antigens, summarize our current knowledge of the phosphorylation of these proteins of human polyomaviruses, and conclude with gaps in the knowledge and a proposal for future research directions.
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Affiliation(s)
- Ugo Moens
- Department of Medical Biology, Faculty of Health Sciences, University of Tromsø—The Arctic University of Norway, 9037 Tromsø, Norway; (M.F.); (B.S.)
| | - Sara Passerini
- Department of Public Health and Infectious Diseases, “Sapienza” University of Rome, 00185 Rome, Italy;
| | - Mar Falquet
- Department of Medical Biology, Faculty of Health Sciences, University of Tromsø—The Arctic University of Norway, 9037 Tromsø, Norway; (M.F.); (B.S.)
| | - Baldur Sveinbjørnsson
- Department of Medical Biology, Faculty of Health Sciences, University of Tromsø—The Arctic University of Norway, 9037 Tromsø, Norway; (M.F.); (B.S.)
| | - Valeria Pietropaolo
- Department of Public Health and Infectious Diseases, “Sapienza” University of Rome, 00185 Rome, Italy;
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Temblador A, Topalis D, van den Oord J, Andrei G, Snoeck R. Organotypic Epithelial Raft Cultures as a Three-Dimensional In Vitro Model of Merkel Cell Carcinoma. Cancers (Basel) 2022; 14:cancers14041091. [PMID: 35205840 PMCID: PMC8870341 DOI: 10.3390/cancers14041091] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/03/2022] [Accepted: 02/14/2022] [Indexed: 01/27/2023] Open
Abstract
Merkel cell carcinoma (MCC) is a rare type of skin cancer for which an in vitro model is still lacking. MCC tumorigenesis is associated either with the integration of Merkel cell polyomavirus into the host genome, or with the accumulation of somatic mutations upon chronic exposure to UV light. Transgenic animals expressing the viral oncoproteins, which are constitutively expressed in virus-related MCC, do not fully recapitulate MCC. Although cell-line-derived xenografts have been established for the two subtypes of MCC, they still present certain limitations. Here, we generated organotypic epithelial raft cultures (OERCs) of MCC by using primary human keratinocytes and both virus-positive and virus-negative MCC cell lines. The primary human keratinocytes and the tumor cells were grown on top of a dermal equivalent. Histological and immunohistochemical examination of the rafts confirmed the growth of MCC cells. Furthermore, gene expression analysis revealed differences in the expression profiles of the distinct tumor cells and the keratinocytes at the transcriptional level. In summary, considering the limited availability of patient samples, OERCs of MCC may constitute a suitable model for evaluating the efficacy and selectivity of new drug candidates against MCC; moreover, they are a potential tool to study the oncogenic mechanisms of this malignancy.
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Affiliation(s)
- Arturo Temblador
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium; (A.T.); (D.T.); (R.S.)
| | - Dimitrios Topalis
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium; (A.T.); (D.T.); (R.S.)
| | - Joost van den Oord
- Laboratory of Translational Cell and Tissue Research, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium;
| | - Graciela Andrei
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium; (A.T.); (D.T.); (R.S.)
- Correspondence:
| | - Robert Snoeck
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium; (A.T.); (D.T.); (R.S.)
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3
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Moens U, Prezioso C, Pietropaolo V. Functional Domains of the Early Proteins and Experimental and Epidemiological Studies Suggest a Role for the Novel Human Polyomaviruses in Cancer. Front Microbiol 2022; 13:834368. [PMID: 35250950 PMCID: PMC8894888 DOI: 10.3389/fmicb.2022.834368] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
As their name indicates, polyomaviruses (PyVs) can induce tumors. Mouse PyV, hamster PyV and raccoon PyV have been shown to cause tumors in their natural host. During the last 30 years, 15 PyVs have been isolated from humans. From these, Merkel cell PyV is classified as a Group 2A carcinogenic pathogen (probably carcinogenic to humans), whereas BKPyV and JCPyV are class 2B (possibly carcinogenic to humans) by the International Agency for Research on Cancer. Although the other PyVs recently detected in humans (referred to here as novel HPyV; nHPyV) share many common features with PyVs, including the viral oncoproteins large tumor antigen and small tumor antigen, as their role in cancer is questioned. This review discusses whether the nHPyVs may play a role in cancer based on predicted and experimentally proven functions of their early proteins in oncogenic processes. The functional domains that mediate the oncogenic properties of early proteins of known PyVs, that can cause cancer in their natural host or animal models, have been well characterized and we examined whether these functional domains are conserved in the early proteins of the nHPyVs and presented experimental evidence that these conserved domains are functional. Furthermore, we reviewed the literature describing the detection of nHPyV in human tumors.
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Affiliation(s)
- Ugo Moens
- Faculty of Health Sciences, Department of Medical Biology, University of Tromsø – The Arctic University of Norway, Tromsø, Norway
- *Correspondence: Ugo Moens,
| | - Carla Prezioso
- Microbiology of Chronic Neuro-Degenerative Pathologies, IRCSS San Raffaele Roma, Rome, Italy
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
| | - Valeria Pietropaolo
- Department of Public Health and Infectious Diseases, Sapienza University of Rome, Rome, Italy
- Valeria Pietropaolo,
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Pajalunga D, Crescenzi M. Restoring the Cell Cycle and Proliferation Competence in Terminally Differentiated Skeletal Muscle Myotubes. Cells 2021; 10:cells10102753. [PMID: 34685732 PMCID: PMC8534385 DOI: 10.3390/cells10102753] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 09/29/2021] [Accepted: 10/12/2021] [Indexed: 01/04/2023] Open
Abstract
Terminal differentiation is an ill-defined, insufficiently characterized, nonproliferation state. Although it has been classically deemed irreversible, it is now clear that at least several terminally differentiated (TD) cell types can be brought back into the cell cycle. We are striving to uncover the molecular bases of terminal differentiation, whose fundamental understanding is a goal in itself. In addition, the field has sought to acquire the ability to make TD cells proliferate. Attaining this end would probe the very molecular mechanisms we are trying to understand. Equally important, it would be invaluable in regenerative medicine, for tissues depending on TD cells and devoid of significant self-repair capabilities. The skeletal muscle has long been used as a model system to investigate the molecular foundations of terminal differentiation. Here, we summarize more than 50 years of studies in this field.
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Affiliation(s)
- Deborah Pajalunga
- Department of Oncology and Molecular Medicine, Italian National Institute of Health, 00161 Rome, Italy;
| | - Marco Crescenzi
- Core Facilities, Italian National Institute of Health, 00161 Rome, Italy
- Correspondence:
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Chk1 and the Host Cell DNA Damage Response as a Potential Antiviral Target in BK Polyomavirus Infection. Viruses 2021; 13:v13071353. [PMID: 34372559 PMCID: PMC8310304 DOI: 10.3390/v13071353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 06/30/2021] [Accepted: 07/07/2021] [Indexed: 12/26/2022] Open
Abstract
The human BK polyomavirus (BKPyV) is latent in the kidneys of most adults, but can be reactivated in immunosuppressed states, such as following renal transplantation. If left unchecked, BK polyomavirus nephropathy (PyVAN) and possible graft loss may result from viral destruction of tubular epithelial cells and interstitial fibrosis. When coupled with regular post-transplant screening, immunosuppression reduction has been effective in limiting BKPyV viremia and the development of PyVAN. Antiviral drugs that are safe and effective in combating BKPyV have not been identified but would be a benefit in complementing or replacing immunosuppression reduction. The present study explores inhibition of the host DNA damage response (DDR) as an antiviral strategy. Immunohistochemical and immunofluorescent analyses of PyVAN biopsies provide evidence for stimulation of a DDR in vivo. DDR pathways were also stimulated in vitro following BKPyV infection of low-passage human renal proximal tubule epithelial cells. The role of Chk1, a protein kinase known to be involved in the replication stress-induced DDR, was examined by inhibition with the small molecule LY2603618 and by siRNA-mediated knockdown. Inhibition of Chk1 resulted in decreased replication of BKPyV DNA and viral spread. Activation of mitotic pathways was associated with the reduction in BKPyV replication. Chk1 inhibitors that are found to be safe and effective in clinical trials for cancer should also be evaluated for antiviral activity against BKPyV.
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Epstein-Barr virus (EBV) and polyomaviruses are detectable in oropharyngeal cancer and EBV may have prognostic impact. Cancer Immunol Immunother 2020; 69:1615-1626. [PMID: 32314041 PMCID: PMC7347695 DOI: 10.1007/s00262-020-02570-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Accepted: 04/06/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND The etiological role of human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma (OPSCC) is confirmed. However, the role of other oncoviruses in OPSCC is unknown. MATERIALS AND METHODS A total of 158 consecutive OPSCC patients treated with curative intent were included. DNA extracted from tumor sections was used to detect Epstein-Barr virus (EBV), HPV, and the following polyomaviruses: John Cunningham virus (JCV), Simian virus 40 (SV40), and BK virus (BKV) with PCR. In addition, p16 expression was studied by immunohistochemistry, and EBV-encoded small RNA (EBER) transcripts were localized by in situ hybridization. The effect of viral status on overall survival (OS) and disease-free survival (DFS) was analyzed. RESULTS A total of 94/158 samples (59.5%) were HPV-positive, 29.1% contained BKV DNA, 20.3% EBV DNA, 13.9% JCV DNA, and 0.6% SV40 DNA. EBER was expressed only in stromal lymphocytes adjacent to the tumor and correlated with HPV positivity (p = 0.026). p16 expression associated only with HPV. None of the three polyomaviruses had an impact on survival. Patients with EBER-positive but HPV-negative OPSCC had significantly poorer OS and DFS than those with HPV-positive OPSCC and slightly worse prognosis compared with the patients with EBER-negative and HPV-negative OPSCC. CONCLUSION Polyomaviruses are detectable in OPSCC but seem to have no impact on survival, whereas HPV was the strongest viral prognostic factor. EBER expression, as a sign of latent EBV infection, may have prognostic impact among patients with HPV-negative OPSCC. EBER analysis may identify a new subgroup of OPSCCs unrelated to HPV.
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The Ubiquitin-Specific Protease Usp7, a Novel Merkel Cell Polyomavirus Large T-Antigen Interaction Partner, Modulates Viral DNA Replication. J Virol 2020; 94:JVI.01638-19. [PMID: 31801860 DOI: 10.1128/jvi.01638-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 12/01/2019] [Indexed: 02/06/2023] Open
Abstract
Merkel cell polyomavirus (MCPyV) is the major cause for Merkel cell carcinoma (MCC), a rare but highly aggressive skin cancer predominantly found in elderly and immunosuppressed patients. The early viral gene products large T-antigen (LT) and small T-antigen (sT) are important for efficient viral DNA replication, and both contribute to transformation processes. These functions are executed mainly through interactions with host factors. Here, we identify the cellular ubiquitin-specific processing protease 7 (Usp7) as a new interaction partner of the MCPyV LT. Using glutathione S-transferase pulldown experiments, we show that MCPyV LT directly binds to Usp7 and that N- as well as C-terminal regions of LT bind to the TRAF (tumor necrosis factor receptor-associated) domain of Usp7. We demonstrate that endogenous Usp7 coprecipitates with MCPyV T-antigens and relocalizes to viral DNA replication centers in cells actively replicating MCPyV genomes. We show that Usp7 does not alter ubiquitination levels of the T-antigens; however, Usp7 binding increases the binding affinity of LT to the origin of replication, thereby negatively regulating viral DNA replication. Together, these data identify Usp7 as a restriction factor of MCPyV replication. In contrast to other DNA viruses, Usp7 does not affect MCPyV gene expression via its ubiquitination activity but influences MCPyV DNA replication solely via a novel mechanism that modulates binding of LT to viral DNA.IMPORTANCE MCPyV is the only human polyomavirus that is associated with cancer; the majority of Merkel cell cancers have a viral etiology. While much emphasis was placed on investigations to understand the transformation process by MCPyV oncoproteins and cellular factors, we have only limited knowledge of cellular factors participating in the MCPyV life cycle. Here, we describe Usp7, a cellular deubiquitination enzyme, as a new factor involved in MCPyV replication. Usp7 is known in the context of large DNA tumor viruses, Epstein-Barr virus (EBV) and Kaposi's sarcoma herpesvirus, to restrict viral replication. Similar to EBV, where Usp7 binding to EBNA1 increases EBNA1 binding affinity to viral DNA, we find MCPyV LT binding to the origin of replication to be increased in the presence of Usp7, resulting in restriction of viral DNA replication. However, Usp7-induced restriction of MCPyV replication is independent of its enzymatic activity, thereby constituting a novel mechanism of Usp7-induced restriction of viral replication.
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Khalili A, Craigie M, Donadoni M, Sariyer IK. Host-Immune Interactions in JC Virus Reactivation and Development of Progressive Multifocal Leukoencephalopathy (PML). J Neuroimmune Pharmacol 2019; 14:649-660. [PMID: 31452013 PMCID: PMC6898772 DOI: 10.1007/s11481-019-09877-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 08/20/2019] [Indexed: 12/12/2022]
Abstract
With the advent of immunomodulatory therapies and the HIV epidemic, the impact of JC Virus (JCV) on the public health system has grown significantly due to the increased incidence of Progressive Multifocal Leukoencephalopathy (PML). Currently, there are no pharmaceutical agents targeting JCV infection for the treatment and the prevention of viral reactivation leading to the development of PML. As JCV primarily reactivates in immunocompromised patients, it is proposed that the immune system (mainly the cellular-immunity component) plays a key role in the regulation of JCV to prevent productive infection and PML development. However, the exact mechanism of JCV immune regulation and reactivation is not well understood. Likewise, the impact of host factors on JCV regulation and reactivation is another understudied area. Here we discuss the current literature on host factor-mediated and immune factor-mediated regulation of JCV gene expression with the purpose of developing a model of the factors that are bypassed during JCV reactivation, and thus are potential targets for the development of therapeutic interventions to suppress PML initiation. Graphical Abstract.
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Affiliation(s)
- Amir Khalili
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Medical Education and Research Building, 7th Floor, Philadelphia, PA, 19140, USA
| | - Michael Craigie
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Medical Education and Research Building, 7th Floor, Philadelphia, PA, 19140, USA
| | - Martina Donadoni
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Medical Education and Research Building, 7th Floor, Philadelphia, PA, 19140, USA
| | - Ilker Kudret Sariyer
- Department of Neuroscience and Center for Neurovirology, Lewis Katz School of Medicine at Temple University, 3500 North Broad Street, Medical Education and Research Building, 7th Floor, Philadelphia, PA, 19140, USA.
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CRISPR/Cas9 Editing of the Polyomavirus Tumor Antigens Inhibits Merkel Cell Carcinoma Growth In Vitro. Cancers (Basel) 2019; 11:cancers11091260. [PMID: 31466237 PMCID: PMC6770690 DOI: 10.3390/cancers11091260] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/21/2019] [Accepted: 08/24/2019] [Indexed: 12/26/2022] Open
Abstract
Merkel cell carcinoma (MCC) is an aggressive type of skin cancer whose main causative agent is Merkel cell polyomavirus (MCPyV). MCPyV is integrated into the genome of the tumor cells in most MCCs. Virus-positive tumor cells constitutively express two viral oncoproteins that promote cell growth: the small (sT) and the large (LT) tumor antigens (TAs). Despite the success of immunotherapies in patients with MCC, not all individuals respond to these treatments. Therefore, new therapeutic options continue to be investigated. Herein, we used CRISPR/Cas9 to target the viral oncogenes in two virus-positive MCC cell lines: MS-1 and WAGA. Frameshift mutations introduced in the target sequence upon repair of the Cas9-induced DNA break resulted in decreased LT protein levels, which subsequently impaired cell proliferation, caused cell cycle arrest, and led to increased apoptosis. Importantly, a virus-negative non-MCC cell line (HEK293T) remained unaffected, as well as those cells expressing a non-targeting single-guide RNA (sgRNA). Thus, we presumed that the noted effects were not due to the off-target activity of the TAs-targeting sgRNAs. Additionally, WAGA cells had altered levels of cellular proteins involved in cell cycle regulation, supporting the observed cell cycle. Taken together, our findings provide evidence for the development of a CRISPR/Cas9-based therapeutic option for virus-positive MCC.
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Craigie M, Cicalese S, Sariyer IK. Neuroimmune Regulation of JC Virus by Intracellular and Extracellular Agnoprotein. J Neuroimmune Pharmacol 2017; 13:126-142. [PMID: 29159704 DOI: 10.1007/s11481-017-9770-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 11/10/2017] [Indexed: 12/12/2022]
Abstract
JC virus (JCV) is a human polyomavirus and the etiologic agent of the demyelinating disease progressive multifocal leukoencephalopathy (PML). PML is observed in patients with underlying immunocompromising conditions, suggesting that neuro-immune interactions between peripheral immune cells and neuro-glia play an important role in controlling viral reactivation in the brain. There is little known about the immunobiology of JCV reactivation in glial cells and the role of immune, glial, and viral players in this regulation. We have previously showed that agnoprotein, a small JCV regulatory protein, is released from infected cells and internalized by neighboring bystander cells. Here we have investigated the possible role of extracellular and intracellular agnoprotein in the neuroimmune response to JC virus. Our findings suggest that glial cells exposed to agnoprotein secrete significantly less GM-CSF, which is mediated by agnoprotein induced suppression of GM-CSF transcription. Likewise, monocytes treated with agnoprotein showed altered differentiation and maturation. In addition, monocytes and microglial cells exposed to agnoprotein showed a significant reduction in their phagocytic activities. Moreover, when an in vitro blood-brain barrier model was used, agnoprotein treatment resulted in decreased monocyte migration through the endothelial cell layer in response to activated astrocytes. All together, these results have revealed a novel immunomodulatory function of agnoprotein during JCV infection within theCNS and open a new avenue of research to better understand the mechanisms associated with JCV reactivation in patients who are at risk of developing PML.
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Affiliation(s)
- Michael Craigie
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 N. Broad Street, Philadelphia, PA, 19140, USA
| | - Stephanie Cicalese
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 N. Broad Street, Philadelphia, PA, 19140, USA
| | - Ilker Kudret Sariyer
- Department of Neuroscience and Center for Neurovirology, Temple University Lewis Katz School of Medicine, 3500 N. Broad Street, Philadelphia, PA, 19140, USA.
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Biology, evolution, and medical importance of polyomaviruses: An update. INFECTION GENETICS AND EVOLUTION 2017. [DOI: 10.1016/j.meegid.2017.06.011] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Delbue S, Comar M, Ferrante P. Review on the role of the human Polyomavirus JC in the development of tumors. Infect Agent Cancer 2017; 12:10. [PMID: 28174598 PMCID: PMC5292005 DOI: 10.1186/s13027-017-0122-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/24/2017] [Indexed: 12/12/2022] Open
Abstract
Almost one fifth of human cancers worldwide are associated with infectious agents, either bacteria or viruses, and this makes the possible association between infections and tumors a relevant research issue. We focused our attention on the human Polyomavirus JC (JCPyV), that is a small, naked DNA virus, belonging to the Polyomaviridae family. It is the recognized etiological agent of the Progressive Multifocal Leukoencephalopathy (PML), a fatal demyelinating disease, occurring in immunosuppressed individuals. JCPyV is able to induce cell transformation in vitro when infecting non-permissive cells, that do not support viral replication and JCPyV inoculation into small animal models and non human primates drives to tumor formation. The molecular mechanisms involved in JCPyV oncogenesis have been extensively studied: the main oncogenic viral protein is the large tumor antigen (T-Ag), that is able to bind, among other cellular factors, both Retinoblastoma protein (pRb) and p53 and to dysregulate the cell cycle, but also the early proteins small tumor antigen (t-Ag) and Agnoprotein appear to cooperate in the process of cell transformation. Consequently, it is not surprising that JCPyV genomic sequences and protein expression have been detected in Central Nervous System (CNS) tumors and colon cancer and an association between this virus and several brain and non CNS-tumors has been proposed. However, the significances of these findings are under debate because there is still insufficient evidence of a casual association between JCPyV and solid cancer development. In this paper we summarized and critically analyzed the published literature, in order to describe the current knowledge on the possible role of JCPyV in the development of human tumors.
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Affiliation(s)
- Serena Delbue
- Department of Biomedical, Surgical and Dental Sciences, University of Milano, Via Pascal, 36-20133 Milan, Italy
| | - Manola Comar
- Department of Medical Sciences, University of Trieste, Trieste, Italy.,Institute for Maternal and Child Health-IRCCS "Burlo Garofolo", 34137 Trieste, Italy
| | - Pasquale Ferrante
- Department of Biomedical, Surgical and Dental Sciences, University of Milano, Via Pascal, 36-20133 Milan, Italy.,Istituto Clinico Città Studi, Milan, Italy
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White MK, Kaminski R, Wollebo H, Hu W, Malcolm T, Khalili K. Gene Editing for Treatment of Neurological Infections. Neurotherapeutics 2016; 13:547-54. [PMID: 27150390 PMCID: PMC4965407 DOI: 10.1007/s13311-016-0439-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The study of neurological infections by viruses defines the field of neurovirology, which has emerged in the last 30 years and was founded upon the discovery of a number of viruses capable of infecting the human nervous system. Studies have focused on the molecular and biological basis of viral neurological diseases with the aim of revealing new therapeutic options. The first studies of neurovirological infections can be traced back to the discovery that some viruses have an affinity for the nervous system with research into rabies by Louis Pasteur and others in the 1880s. Today, the immense public health impact of neurovirological infections is illustrated by diseases such as neuroAIDS, progressive multifocal leukoencephalopathy, and viral encephalitis. Recent research has seen the development of powerful new techniques for gene editing that promise revolutionary opportunities for the development of novel therapeutic options. In particular, clustered regulatory interspaced short palindromic repeat-associated 9 system provides an effective, highly specific and versatile tool for targeting DNA viruses that are beginning to allow the development of such new approaches. In this short review, we discuss these recent developments, how they pertain to neurological infections, and future prospects.
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Affiliation(s)
- Martyn K White
- Department of Neuroscience, Center for Neurovirology, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA
| | - Rafal Kaminski
- Department of Neuroscience, Center for Neurovirology, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA
| | - Hassen Wollebo
- Department of Neuroscience, Center for Neurovirology, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA
| | - Wenhui Hu
- Department of Neuroscience, Center for Neurovirology, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA
| | - Thomas Malcolm
- Excision Biotherapeutics, Inc., 3624 Market Street, #514, Philadelphia, PA, 19104, USA
| | - Kamel Khalili
- Department of Neuroscience, Center for Neurovirology, Comprehensive NeuroAIDS Center, Lewis Katz School of Medicine at Temple University, 3500 N. Broad Street, 7th Floor, Philadelphia, PA, 19140, USA.
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14
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Emerging differential roles of the pRb tumor suppressor in trichodysplasia spinulosa-associated polyomavirus and Merkel cell polyomavirus pathogeneses. J Clin Virol 2016; 76:40-3. [DOI: 10.1016/j.jcv.2016.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 12/21/2015] [Accepted: 01/05/2016] [Indexed: 01/13/2023]
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15
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Saribas AS, Coric P, Hamazaspyan A, Davis W, Axman R, White MK, Abou-Gharbia M, Childers W, Condra JH, Bouaziz S, Safak M. Emerging From the Unknown: Structural and Functional Features of Agnoprotein of Polyomaviruses. J Cell Physiol 2016; 231:2115-27. [PMID: 26831433 DOI: 10.1002/jcp.25329] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 02/01/2016] [Indexed: 12/15/2022]
Abstract
Agnoprotein is an important regulatory protein of polyomaviruses, including JCV, BKV, and SV40. In the absence of its expression, these viruses are unable to sustain their productive life cycle. It is a highly basic phosphoprotein that localizes mostly to the perinuclear area of infected cells, although a small amount of the protein is also found in nucleus. Much has been learned about the structure and function of this important regulatory protein in recent years. It forms highly stable dimers/oligomers in vitro and in vivo through its Leu/Ile/Phe-rich domain. Structural NMR studies revealed that this domain adopts an alpha-helix conformation and plays a critical role in the stability of the protein. It associates with cellular proteins, including YB-1, p53, Ku70, FEZ1, HP1α, PP2A, AP-3, PCNA, and α-SNAP; and viral proteins, including small t antigen, large T antigen, HIV-1 Tat, and JCV VP1; and significantly contributes the viral transcription and replication. This review summarizes the recent advances in the structural and functional properties of this important regulatory protein. J. Cell. Physiol. 231: 2115-2127, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- A Sami Saribas
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Pascale Coric
- Université Paris Descartes, Sorbonne Paris Cité, Laboratoire de Cristallographie et RMN Biologiques, 4 av. de l'Observatoire, Paris, France
| | - Anahit Hamazaspyan
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - William Davis
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Rachel Axman
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Martyn K White
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
| | - Magid Abou-Gharbia
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, Pennsylvania
| | - Wayne Childers
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, Pennsylvania
| | - Jon H Condra
- Moulder Center for Drug Discovery Research, Temple University School of Pharmacy, Philadelphia, Pennsylvania
| | - Serge Bouaziz
- Université Paris Descartes, Sorbonne Paris Cité, Laboratoire de Cristallographie et RMN Biologiques, 4 av. de l'Observatoire, Paris, France
| | - Mahmut Safak
- Department of Neuroscience, Laboratory of Molecular Neurovirology, MERB-757, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania
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16
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Wollebo HS, Bellizzi A, Kaminski R, Hu W, White MK, Khalili K. CRISPR/Cas9 System as an Agent for Eliminating Polyomavirus JC Infection. PLoS One 2015; 10:e0136046. [PMID: 26360417 PMCID: PMC4567079 DOI: 10.1371/journal.pone.0136046] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 07/30/2015] [Indexed: 12/21/2022] Open
Abstract
Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disease of the central nervous system (CNS) caused by reactivation of the human polyomavirus JCV gene expression and its replication in oligodendrocytes, the myelin producing cells in the brain. Once a rare disease seen in patients with lymphotproliferative and myeloproliferative disorders, PML has been seen more frequently in HIV-1 positive/AIDS patients as well as patients undergoing immunomodulatory therapy due for autoimmune disorders including multiple sclerosis, rheumatoid arthritis, and others. As of now there is no cure for PML and in most cases disease progression leads to death within two years. Similar to other polyomaviruses, the JCV genome is small circular double stranded DNA that includes coding sequences for the viral early protein, T-antigen, which is critical for directing viral reactivation and lytic infection. Here, we employ a newly developed gene editing strategy, CRISPR/Cas9, to introduce mutations in the viral genome and, by inactivating the gene encoding T-antigen, inhibit viral replication. We first used bioinformatics screening and identified several potential targets within the JCV T-antigen gene that can serve as sites for the creation of guide RNAs (gRNAs) for positioning the Cas9 nuclease on the designated area of the viral genome for editing. Results from a series of integrated genetic and functional studies showed that transient or conditional expression of Cas9 and gRNAs specifically targets the DNA sequences corresponding to the N-terminal region of T-antigen, and by introducing mutation, interferes with expression and function of of the viral protein, hence suppressing viral replication in permissive cells. Results from SURVEYOR assay revealed no off-target effects of the JCV-specific CRISPR/Cas9 editing apparatus. These observations provide the first evidence for the employment of a gene editing strategy as a promising tool for the elimination of the JCV genome and a potential cure for PML.
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MESH Headings
- Antigens, Viral, Tumor/genetics
- Base Sequence
- CRISPR-Cas Systems
- Cell Line, Tumor
- Gene Expression
- Gene Knockdown Techniques
- Gene Targeting
- Genetic Therapy/methods
- Genome, Viral
- Humans
- JC Virus/genetics
- Leukoencephalopathy, Progressive Multifocal/therapy
- Leukoencephalopathy, Progressive Multifocal/virology
- Molecular Sequence Data
- Mutation
- Promoter Regions, Genetic
- RNA Editing
- RNA, Guide, CRISPR-Cas Systems/chemistry
- RNA, Guide, CRISPR-Cas Systems/genetics
- Sequence Alignment
- Virus Replication
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Affiliation(s)
- Hassen S. Wollebo
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, PA, 19122, United States of America
| | - Anna Bellizzi
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, PA, 19122, United States of America
| | - Rafal Kaminski
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, PA, 19122, United States of America
| | - Wenhui Hu
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, PA, 19122, United States of America
| | - Martyn K. White
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, PA, 19122, United States of America
| | - Kamel Khalili
- Department of Neuroscience, Temple University School of Medicine, Philadelphia, PA, 19122, United States of America
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Brincidofovir (CMX001) inhibits BK polyomavirus replication in primary human urothelial cells. Antimicrob Agents Chemother 2015; 59:3306-16. [PMID: 25801568 DOI: 10.1128/aac.00238-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/17/2015] [Indexed: 02/08/2023] Open
Abstract
BK polyomavirus (BKPyV)-associated hemorrhagic cystitis (PyVHC) complicates 5 to 15% of allogeneic hematopoietic stem cell transplantations. Targeted antivirals are still unavailable. Brincidofovir (BCV; previously CMX001) has shown inhibitory activity against diverse viruses, including BKPyV in a primary human renal tubule cell culture model of polyomavirus-associated nephropathy. We investigated the effects of BCV in BKPyV-infected and uninfected primary human urothelial cells (HUCs), the target cells of BKPyV in PyVHC. The BCV concentrations causing 50 and 90% reductions (EC50 and EC90) in the number of intracellular BKPyV genome equivalents per cell (icBKPyV) were 0.27 μM and 0.59 μM, respectively. At 0.63 μM, BCV reduced viral late gene expression by 90% and halted progeny release. Preinfection treatment for only 24 h reduced icBKPyV similarly to treatment from 2 to 72 h postinfection, while combined pre- and postinfection treatment suppressed icBKPyV completely. After investigating BCV's effects on HUC viability, mean selectivity indices at 50 and 90% inhibition (SI50 and SI90) calculated for cellular DNA replication were 2.7 and 2.9, respectively, those for mitochondrial activity were 8.9 and 10.4, those for total ATP were 8.6 and 8.2, and those for membrane integrity were 25.9 and 16.7. The antiviral and cytostatic effects, but less so the cytotoxic effects, were inversely related to cell density. The cytotoxic effects at concentrations of ≥10 μM were rapid and likely related to BCV's lipid moiety. After carefully defining the antiviral, cytostatic, and cytotoxic properties of BCV in HUCs, we conclude that a preemptive or prophylactic approach in PyVHC is likely to give the best results.
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Choi PM, Sun RC, Sommovilla J, Diaz-Miron J, Guo J, Erwin CR, Warner BW. IGF-2 is necessary for retinoblastoma-mediated enhanced adaptation after small-bowel resection. J Gastrointest Surg 2014; 18:1887-93. [PMID: 25002022 PMCID: PMC4201888 DOI: 10.1007/s11605-014-2586-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 06/24/2014] [Indexed: 01/31/2023]
Abstract
Previously, we have demonstrated that genetically disrupting retinoblastoma protein (Rb) expression in enterocytes results in taller villi, mimicking resection-induced adaption responses. Rb deficiency also results in elevated insulin-like growth factor-2 (IGF-2) expression in villus enterocytes. We propose that postoperative disruption of Rb results in enhanced adaptation which is driven by IGF-2. Inducible, intestine-specific Rb-null mice (iRbIKO) and wild-type (WT) littermates underwent a 50% proximal small-bowel resection (SBR) at 7-9 weeks of age. They were then given tamoxifen on postoperative days (PODs) 4-6 and harvested on POD 28. The experiment was then repeated on double knockouts of both IGF-2 and Rb (IGF-2 null/iRbIKO). iRbIKO mice demonstrated enhanced resection-induced adaptive villus growth after SBR and increased IGF-2 messenger RNA (mRNA) in ileal villus enterocytes compared to their WT littermates. In the IGF-2 null/iRbIKO double-knockout mice, there was no additional villus growth beyond what was expected of normal resection-induced adaptation. Adult mice in which Rb is inducibly deleted from the intestinal epithelium following SBR have augmented adaptive growth. IGF-2 expression is necessary for enhanced adaptation associated with acute intestinal Rb deficiency.
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Affiliation(s)
- Pamela M Choi
- Division of Pediatric Surgery, Department of Surgery, St Louis Children's Hospital, Washington University School of Medicine, One Children's Place, Suite 5S40, St Louis, MO, 63110, USA
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Sadeghi F, Salehi-Vaziri M, Ghodsi SM, Alizadeh A, Bokharaei-Salim F, Saroukalaei ST, Mirbolouk M, Monavari SH, Keyvani H. Prevalence of JC polyomavirus large T antigen sequences among Iranian patients with central nervous system tumors. Arch Virol 2014; 160:61-8. [PMID: 25218012 DOI: 10.1007/s00705-014-2230-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 09/03/2014] [Indexed: 01/20/2023]
Abstract
The human neurotropic JC virus (JCV) is of significant interest due to its experimental neuro- oncogenic potential. In clinical samples from human central nervous system (CNS) tumors, detection of JCV sequences suggests a possible association with CNS neoplasms, but the results are discrepant worldwide. To assess the prevalence of JCV sequences in Iranian patients with primary and metastatic CNS malignancies, a total of 58 fresh CNS tumors were examined by quantitative real-time PCR targeting the JCV large T antigen (LT-Ag) gene, and JCV DNA load was determined as viral copy number per cell. All patients were immunocompetent, and none of them had received immunosuppressive therapy before surgical operation. JC virus LT-Ag sequences were found in a total of 15 (25.9 %) out of the 58 tested samples. In primary CNS tumors, JCV sequences were identified more frequently in meningiomas (50.0 %) and schwannomas (35.7 %). In metastatic CNS tumors, JCV LT-Ag was identified in one case with brain adenocarcinoma originating from lung cancer. No statistically significant association between JCV positivity and various types of CNS malignancies was observed (P = 0.565). The mean JCV LT-Ag copy number in 15 positive cases was 1.8 × 10(-4) ± 4.5 × 10(-4) copies per cell (range 1.0 × 10(-5)-1.78 × 10(-3) copies per cell). An inverse correlation between white blood cell (WBC) count and JCV copy number was observed, but this correlation was not statistically significant (R = -0.198, P = 0.480). This study provides the first data on the prevalence of JCV in primary and metastatic CNS tumors from Iranian patients.
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Affiliation(s)
- Farzin Sadeghi
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
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20
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The interaction of nonstructural protein 9 with retinoblastoma protein benefits the replication of genotype 2 porcine reproductive and respiratory syndrome virus in vitro. Virology 2014; 464-465:432-440. [PMID: 25146601 PMCID: PMC7112046 DOI: 10.1016/j.virol.2014.07.036] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/18/2014] [Accepted: 07/21/2014] [Indexed: 11/23/2022]
Abstract
The nonstructural protein 9 (Nsp9) of porcine reproductive and respiratory syndrome virus (PRRSV) is a RNA-dependent RNA polymerase (RdRp) that plays a vital role in viral replication. This study first demonstrated that the Nsp9 of genotype 2 PRRSV interacted with cellular retinoblastoma protein (pRb), and Nsp9 co-localized with pRb in the cytoplasm of PRRSV-infected MARC-145 cells and pulmonary alveolar macrophages (PAMs). Next, the overexpression of truncated pRb was shown to inhibit the PRRSV replication and silencing the pRb gene could facilitate the PRRSV replication in MARC-145 cells. Finally, the pRb level was confirmed to be down-regulated in PRRSV-infected MARC-145 cells, and Nsp9 was shown to promote the pRb degradation by proteasome pathway. These findings indicate that the interaction of Nsp 9 with pRb benefits the replication of genotype 2 PRRSV in vitro, helping to understand the roles of Nsp9 in the replication and pathogenesis of PRRSV. The Nsp9 of genotype 2 PRRSV interacted with retinoblastoma protein (pRb). The pRb level was down-regulated in PRRSV-infected MARC-145 cells. The Nsp9 of genotype 2 PRRSV promoted the pRb degradation by proteasome pathway. The interaction of Nsp 9 with pRb benefits the genotype 2 PRRSV replication in vitro.
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21
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Wierstra I. The transcription factor FOXM1 (Forkhead box M1): proliferation-specific expression, transcription factor function, target genes, mouse models, and normal biological roles. Adv Cancer Res 2013; 118:97-398. [PMID: 23768511 DOI: 10.1016/b978-0-12-407173-5.00004-2] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
FOXM1 (Forkhead box M1) is a typical proliferation-associated transcription factor, which stimulates cell proliferation and exhibits a proliferation-specific expression pattern. Accordingly, both the expression and the transcriptional activity of FOXM1 are increased by proliferation signals, but decreased by antiproliferation signals, including the positive and negative regulation by protooncoproteins or tumor suppressors, respectively. FOXM1 stimulates cell cycle progression by promoting the entry into S-phase and M-phase. Moreover, FOXM1 is required for proper execution of mitosis. Accordingly, FOXM1 regulates the expression of genes, whose products control G1/S-transition, S-phase progression, G2/M-transition, and M-phase progression. Additionally, FOXM1 target genes encode proteins with functions in the execution of DNA replication and mitosis. FOXM1 is a transcriptional activator with a forkhead domain as DNA binding domain and with a very strong acidic transactivation domain. However, wild-type FOXM1 is (almost) inactive because the transactivation domain is repressed by three inhibitory domains. Inactive FOXM1 can be converted into a very potent transactivator by activating signals, which release the transactivation domain from its inhibition by the inhibitory domains. FOXM1 is essential for embryonic development and the foxm1 knockout is embryonically lethal. In adults, FOXM1 is important for tissue repair after injury. FOXM1 prevents premature senescence and interferes with contact inhibition. FOXM1 plays a role for maintenance of stem cell pluripotency and for self-renewal capacity of stem cells. The functions of FOXM1 in prevention of polyploidy and aneuploidy and in homologous recombination repair of DNA-double-strand breaks suggest an importance of FOXM1 for the maintenance of genomic stability and chromosomal integrity.
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22
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White spot syndrome virus IE1 and WSV056 modulate the G1/S transition by binding to the host retinoblastoma protein. J Virol 2013; 87:12576-82. [PMID: 24027329 DOI: 10.1128/jvi.01551-13] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
DNA viruses often target cellular proteins to modulate host cell cycles and facilitate viral genome replication. However, whether proliferation of white spot syndrome virus (WSSV) requires regulation of the host cell cycle remains unclear. In the present study, we show that two WSSV paralogs, IE1 and WSV056, can interact with Litopenaeus vannamei retinoblastoma (Rb)-like protein (lv-RBL) through the conserved LxCxE motif. Further investigation revealed that IE1 and WSV056 could also bind to Drosophila retinoblastoma family protein 1 (RBF1) in a manner similar to how they bind to lv-RBL. Using the Drosophila RBF-E2F pathway as a model system, we demonstrated that both IE1 and WSV056 could sequester RBF1 from Drosophila E2F transcription factor 1 (E2F1) and subsequently activate E2F1 to stimulate the G1/S transition. Our findings provide the first evidence that WSSV may regulate cell cycle progression by targeting the Rb-E2F pathway.
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23
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Rinaldo CH, Tylden GD, Sharma BN. The human polyomavirus BK (BKPyV): virological background and clinical implications. APMIS 2013; 121:728-45. [PMID: 23782063 DOI: 10.1111/apm.12134] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 04/27/2013] [Indexed: 12/13/2022]
Abstract
Polyomavirus BK (BKPyV) infects most people subclinically during childhood and establishes a lifelong infection in the renourinary tract. In most immunocompetent individuals, the infection is completely asymptomatic, despite frequent episodes of viral reactivation with shedding into the urine. In immunocompromised patients, reactivation followed by high-level viral replication can lead to severe disease: 1-10% of kidney transplant patients develop polyomavirus-associated nephropathy (PyVAN) and 5-15% of allogenic hematopoietic stem cell transplant patients develop polyomavirus-associated haemorrhagic cystitis (PyVHC). Other conditions such as ureteric stenosis, encephalitis, meningoencephalitis, pneumonia and vasculopathy have also been associated with BKPyV infection in immunocompromised individuals. Although BKPyV has been associated with cancer development, especially in the bladder, definitive evidence of a role in human malignancy is lacking. Diagnosis of PyVAN and PyVHC is mainly achieved by quantitative PCR of urine and plasma, but also by cytology, immunohistology and electron microscopy. Despite more than 40 years of research on BKPyV, there is still no effective antiviral therapy. The current treatment strategy for PyVAN is to allow reconstitution of immune function by reducing or changing the immunosuppressive medication. For PyVHC, treatment is purely supportive. Here, we present a summary of the accrued knowledge regarding BKPyV.
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Affiliation(s)
- Christine Hanssen Rinaldo
- Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway.
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24
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Bellizzi A, Nardis C, Anzivino E, Rodìo DM, Fioriti D, Mischitelli M, Chiarini F, Pietropaolo V. Human polyomavirus JC reactivation and pathogenetic mechanisms of progressive multifocal leukoencephalopathy and cancer in the era of monoclonal antibody therapies. J Neurovirol 2013; 18:1-11. [PMID: 22290500 DOI: 10.1007/s13365-012-0080-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 12/28/2011] [Accepted: 01/09/2012] [Indexed: 12/12/2022]
Abstract
Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the neurotropic human polyomavirus JC (JCV) lytic infection of oligodendrocytes. PML was first described as a complication of lymphoproliferative disorders more than 50 years ago and emerged as a major complication of human immunodeficiency virus (HIV) infection in the 1980s. Despite the ubiquity of this virus, PML is rare and always seen in association with underlying immunosuppressive condition, such as HIV infection, autoimmune diseases, cancer, and organ transplantation. JCV remains quiescent in the kidneys, where it displays a stable archetypal non-coding control region (NCCR). Conversely, rearranged JCV NCCR, including tandem repeat patterns found in the brain of PML patients, have been associated with neurovirulence. The specific site and mechanism of JCV NCCR transformation is unknown. According to one model, during the course of immunosuppression, JCV departs from its latent state and after entering the brain, productively infects and destroys oligodendrocytes. Although the majority of PML cases occur in severely immunesuppressed individuals, PML has been increasingly diagnosed in patients treated with biological therapies such as monoclonal antibodies (mAbs) that modulate immune system functions: in fact, CD4+ and CD8+ T lymphopenia, resulting from this immunomodulatory therapy, are the primary risk factor. Furthermore, JCV reactivation in nonpermissive cells after treatment with mAbs, such as intestinal epithelial cells in Crohn's disease patients, in association with other host tumor-inducing factors, could provide valid information on the role of JCV in several malignancies, such as colorectal cancer.
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Affiliation(s)
- A Bellizzi
- Department of Health Sciences and Infectious Diseases, Sapienza University, P.le Aldo Moro, 5, 00185 Rome, Italy
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Wierstra I. FOXM1 (Forkhead box M1) in tumorigenesis: overexpression in human cancer, implication in tumorigenesis, oncogenic functions, tumor-suppressive properties, and target of anticancer therapy. Adv Cancer Res 2013; 119:191-419. [PMID: 23870513 DOI: 10.1016/b978-0-12-407190-2.00016-2] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
FOXM1 (Forkhead box M1) is a typical proliferation-associated transcription factor and is also intimately involved in tumorigenesis. FOXM1 stimulates cell proliferation and cell cycle progression by promoting the entry into S-phase and M-phase. Additionally, FOXM1 is required for proper execution of mitosis. In accordance with its role in stimulation of cell proliferation, FOXM1 exhibits a proliferation-specific expression pattern and its expression is regulated by proliferation and anti-proliferation signals as well as by proto-oncoproteins and tumor suppressors. Since these factors are often mutated, overexpressed, or lost in human cancer, the normal control of the foxm1 expression by them provides the basis for deregulated FOXM1 expression in tumors. Accordingly, FOXM1 is overexpressed in many types of human cancer. FOXM1 is intimately involved in tumorigenesis, because it contributes to oncogenic transformation and participates in tumor initiation, growth, and progression, including positive effects on angiogenesis, migration, invasion, epithelial-mesenchymal transition, metastasis, recruitment of tumor-associated macrophages, tumor-associated lung inflammation, self-renewal capacity of cancer cells, prevention of premature cellular senescence, and chemotherapeutic drug resistance. However, in the context of urethane-induced lung tumorigenesis, FOXM1 has an unexpected tumor suppressor role in endothelial cells because it limits pulmonary inflammation and canonical Wnt signaling in epithelial lung cells, thereby restricting carcinogenesis. Accordingly, FOXM1 plays a role in homologous recombination repair of DNA double-strand breaks and maintenance of genomic stability, that is, prevention of polyploidy and aneuploidy. The implication of FOXM1 in tumorigenesis makes it an attractive target for anticancer therapy, and several antitumor drugs have been reported to decrease FOXM1 expression.
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Molecular biology, epidemiology, and pathogenesis of progressive multifocal leukoencephalopathy, the JC virus-induced demyelinating disease of the human brain. Clin Microbiol Rev 2012; 25:471-506. [PMID: 22763635 DOI: 10.1128/cmr.05031-11] [Citation(s) in RCA: 289] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Progressive multifocal leukoencephalopathy (PML) is a debilitating and frequently fatal central nervous system (CNS) demyelinating disease caused by JC virus (JCV), for which there is currently no effective treatment. Lytic infection of oligodendrocytes in the brain leads to their eventual destruction and progressive demyelination, resulting in multiple foci of lesions in the white matter of the brain. Before the mid-1980s, PML was a relatively rare disease, reported to occur primarily in those with underlying neoplastic conditions affecting immune function and, more rarely, in allograft recipients receiving immunosuppressive drugs. However, with the onset of the AIDS pandemic, the incidence of PML has increased dramatically. Approximately 3 to 5% of HIV-infected individuals will develop PML, which is classified as an AIDS-defining illness. In addition, the recent advent of humanized monoclonal antibody therapy for the treatment of autoimmune inflammatory diseases such as multiple sclerosis (MS) and Crohn's disease has also led to an increased risk of PML as a side effect of immunotherapy. Thus, the study of JCV and the elucidation of the underlying causes of PML are important and active areas of research that may lead to new insights into immune function and host antiviral defense, as well as to potential new therapies.
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Samaka RM, Abd El-Wahed MM, Aiad HA, Kandil MA, Al-Sharaky DR. Does JC virus have a role in the etiology and prognosis of Egyptian colorectal carcinoma? APMIS 2012; 121:316-28. [PMID: 23030805 DOI: 10.1111/apm.12001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 08/19/2012] [Indexed: 12/23/2022]
Abstract
John Cunningham virus (JCV) encodes an oncogenic T-antigen, which is capable of interacting with key growth regulatory pathways. JCV definite role as causal agent of human cancer, still awaits final confirmation. The present study was conducted to assess the possible role of JCV in Egyptian colorectal carcinoma (CRC) and correlate the expression with the clinicopathological features and survival. JCV in situ hybridization (ISH) signals and large T antigen immunoreactivity were examined in 87 colonic specimens. Positive glandular JCV ISH signals were detected in 20%, 25% and 40% of normal, adenoma and CRC cases respectively. Stromal JCV ISH signals were identified in 26% of CRC cases and 5% of adenoma however, normal mucosa did not show stromal positivity with significant difference (p = 0.03). Glandular JCV expression was significantly associated with high grade (p = 0.03), high mitotic index (p=0.02) and low apoptotic index (p = 0.00). Positive stromal signals were significantly associated with low apoptosis (p = 0.00). No positive nuclear immunostaining of JCV large T antigen was detected in all specimens. JCV stromal expression was the 2nd most powerful indicator of short survival and bad prognosis (p = 0.03) in CRC patients. JCV might play an etiological role in CRC tumorogenesis and short survival in Egyptian CRC patients.
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Affiliation(s)
- Rehab M Samaka
- Pathology Department, Menoufyia University, Shebin El-Kom, Egypt.
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Saeed M, Schwarze F, Loidl A, Meraner J, Lechner M, Loidl P. In vitro phosphorylation and acetylation of the murine pocket protein Rb2/p130. PLoS One 2012; 7:e46174. [PMID: 23029429 PMCID: PMC3454344 DOI: 10.1371/journal.pone.0046174] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 08/30/2012] [Indexed: 12/04/2022] Open
Abstract
The retinoblastoma protein (pRb) and the related proteins Rb2/p130 and 107 represent the “pocket protein” family of cell cycle regulators. A key function of these proteins is the cell cycle dependent modulation of E2F-regulated genes. The biological activity of these proteins is controlled by acetylation and phosphorylation in a cell cycle dependent manner. In this study we attempted to investigate the interdependence of acetylation and phosphorylation of Rb2/p130 in vitro. After having identified the acetyltransferase p300 among several acetyltransferases to be associated with Rb2/p130 during S-phase in NIH3T3 cells in vivo, we used this enzyme and the CDK4 protein kinase for in vitro modification of a variety of full length Rb2/p130 and truncated versions with mutations in the acetylatable lysine residues 1079, 128 and 130. Mutation of these residues results in the complete loss of Rb2/p130 acetylation. Replacement of lysines by arginines strongly inhibits phosphorylation of Rb2/p130 by CDK4; the inhibitory effect of replacement by glutamines is less pronounced. Preacetylation of Rb2/p130 strongly enhances CDK4-catalyzed phosphorylation, whereas deacetylation completely abolishes in vitro phosphorylation. In contrast, phosphorylation completely inhibits acetylation of Rb2/p130 by p300. These results suggest a mutual interdependence of modifications in a way that acetylation primes Rb2/p130 for phosphorylation and only dephosphorylated Rb2/p130 can be subject to acetylation. Human papillomavirus 16-E7 protein, which increases acetylation of Rb2/p130 by p300 strongly reduces phosphorylation of this protein by CDK4. This suggests that the balance between phosphorylation and acetylation of Rb2/p130 is essential for its biological function in cell cycle control.
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Affiliation(s)
- Muhammad Saeed
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Florian Schwarze
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Adele Loidl
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Joachim Meraner
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Markus Lechner
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
| | - Peter Loidl
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
- * E-mail:
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29
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Sariyer IK, Merabova N, Patel PK, Knezevic T, Rosati A, Turco MC, Khalili K. Bag3-induced autophagy is associated with degradation of JCV oncoprotein, T-Ag. PLoS One 2012; 7:e45000. [PMID: 22984599 PMCID: PMC3440322 DOI: 10.1371/journal.pone.0045000] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 08/11/2012] [Indexed: 01/12/2023] Open
Abstract
JC virus, JCV, is a human neurotropic polyomavirus whose replication in glial cells causes the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). In addition, JCV possesses oncogenic activity and expression of its transforming protein, large T-antigen (T-Ag), in several experimental animals induces tumors of neural origin. Further, the presence of JCV DNA and T-Ag have been repeatedly observed in several human malignant tissues including primitive neuroectodermal tumors and glioblastomas. Earlier studies have demonstrated that Bag3, a member of the Bcl-2-associated athanogene (Bag) family of proteins, which is implicated in autophagy and apoptosis, is downregulated upon JCV infection of glial cells and that JCV T-Ag is responsible for suppressing the activity of the BAG3 promoter. Here, we investigated the possible impact of Bag3 on T-Ag expression in JCV-infected human primary glial cells as well as in cells derived from T-Ag-induced medulloblastoma in transgenic animals. Results from these studies revealed that overexpression of Bag3 drastically decreases the level of T-Ag expression by inducing the autophagic degradation of the viral protein. Interestingly, this event leads to the inhibition of JCV infection of glial cells, suggesting that the reduced levels of T-antigen seen upon the overexpression of Bag3 has a biological impact on the viral lytic cycle. Results from protein-protein interaction studies showed that T-Ag and Bag3 physically interact with each other through the zinc-finger of T-Ag and the proline rich domains of Bag3, and this interaction is important for the autophagic degradation of T-Ag. Our observations open a new avenue of research for better understanding of virus-host interaction by investigating the interplay between T-Ag and Bag3, and their impact on the development of JCV-associated diseases.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Animals
- Antigens, Polyomavirus Transforming/genetics
- Antigens, Polyomavirus Transforming/metabolism
- Apoptosis Regulatory Proteins
- Astrocytes/cytology
- Astrocytes/metabolism
- Astrocytes/virology
- Autophagy
- Binding Sites
- Blotting, Western
- Cell Line, Tumor
- Cells, Cultured
- DNA, Viral/genetics
- Gene Dosage
- Host-Pathogen Interactions
- Humans
- JC Virus/genetics
- JC Virus/metabolism
- JC Virus/physiology
- Mice
- Mice, Transgenic
- Polymerase Chain Reaction
- Protein Binding
- Proteolysis
- RNA Interference
- Tumor Cells, Cultured
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Affiliation(s)
- Ilker Kudret Sariyer
- Department of Neuroscience and Center for Neurovirology Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Nana Merabova
- Department of Neuroscience and Center for Neurovirology Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Prem Kumer Patel
- Department of Neuroscience and Center for Neurovirology Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Tijana Knezevic
- Department of Neuroscience and Center for Neurovirology Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Alessandra Rosati
- Department of Pharmaceutical and Biomedical Sciences (FARMABIOMED), University of Salerno, Fisciano, Italy
| | - Maria C. Turco
- Department of Pharmaceutical and Biomedical Sciences (FARMABIOMED), University of Salerno, Fisciano, Italy
| | - Kamel Khalili
- Department of Neuroscience and Center for Neurovirology Temple University School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Abstract
Medulloblastoma (MB) is a cancer of the cerebellum and the most common primary pediatric malignancy of the central nervous system. Classified as a primitive neural ectoderm tumor; it is thought to arise from granule cell precursors in the cerebellum. The standard of care consists of surgery, chemotherapy and age-dependent radiation therapy. Despite aggressive multimodality therapy; approximately 30% of MB patients remain incurable. Moreover, for long-term survivors, the treatment related sequelae are often debilitating. Side effects include cerebellar mutism, sterility, neurocognitive deficits, and a substantial risk of developing secondary cancers. In a quest for more effective and targeted therapies, scientists have begun to investigate the biological events that not only initiate but also sustain the malignant phenotype in MB. Of particular interest is, the role of the tumor microenvironment in tumor pathogenesis. This review seeks to highlight several key processes observed in cancer biology, particularly the involvement of the tumor microenvironment, with relevant examples from MB.
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Affiliation(s)
- Tiara Byrd
- Department of Pediatrics, Baylor College of Medicine, Center for Cell and Gene Therapy, Houston, Texas 77030, USA.
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31
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Houben R, Adam C, Baeurle A, Hesbacher S, Grimm J, Angermeyer S, Henzel K, Hauser S, Elling R, Bröcker EB, Gaubatz S, Becker JC, Schrama D. An intact retinoblastoma protein-binding site in Merkel cell polyomavirus large T antigen is required for promoting growth of Merkel cell carcinoma cells. Int J Cancer 2011; 130:847-56. [PMID: 21413015 DOI: 10.1002/ijc.26076] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Accepted: 02/04/2011] [Indexed: 01/01/2023]
Abstract
Merkel cell carcinoma (MCC) is a highly aggressive skin cancer that frequently harbours Merkel cell polyomavirus (MCV) DNA integrated in the genome of the tumor cells. In our study, we elaborate our recent finding that MCV-positive MCC cell lines require the expression of the viral T antigens (TA). Indeed, in a xeno-transplantation model, we prove that TA expression is essential also in an in vivo situation, as knock down of TA leads to tumor regression. Moreover, rescuing TA short hairpin RNA (shRNA)-treated MCV-positive MCC cells by ectopic expression of shRNA-insensitive TAs clearly demonstrates that the observed effect is caused by TA knockdown. Notably, introduction of a mutation in the LTA protein interfering with LTA binding to the retinoblastoma protein (RB) ablated this rescue. The importance of this interaction was further confirmed as LTA-specific knockdown leads to explicit cell growth inhibition. In summary, the presented data demonstrate that established MCV-positive MCC tumors critically depend on TA expression, in particular the LTA and RB interaction, for sustained tumor growth. Consequently, interference with LTA/RB interaction appears as promising strategy to treat MCC.
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Affiliation(s)
- Roland Houben
- Department of Dermatology, University Hospital Würzburg, Würzburg, Germany.
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32
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Regulation of human neurotropic JC virus replication by alternative splicing factor SF2/ASF in glial cells. PLoS One 2011; 6:e14630. [PMID: 21297941 PMCID: PMC3031499 DOI: 10.1371/journal.pone.0014630] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 01/09/2011] [Indexed: 11/19/2022] Open
Abstract
Background The human neurotropic virus, JC virus (JCV), is the etiologic agent of the fatal demyelinating disease of the central nervous system, Progressive Multifocal Leukoencephlopathy (PML) that is seen primarily in immunodeficient individuals. Productive infection of JCV occurs only in glial cells, and this restriction is, to a great extent, due to the activation of the viral promoter that has cell type-specific characteristics. Earlier studies led to the hypothesis that glial-specific activation of the JCV promoter is mediated through positive and negative transcription factors that control reactivation of the JCV genome under normal physiological conditions and suppress its activation in non-glial cells. Methodololgy/Principal Findings Using a variety of virological and molecular biological approaches, we demonstrate that the alternative splicing factor SF2/ASF has the capacity to exert a negative effect on transcription of the JCV promoter in glial cells through direct association with a specific DNA sequence within the viral enhancer/promoter region. Our results show that down-regulation of SF2/ASF in fetal and adult glial cells increases the level of JCV gene expression and its replication indicating that negative regulation of the JCV promoter by SF2/ASF may control reactivation of JCV replication in brain. Conclusions/Significance Our results establish a new regulatory role for SF2/ASF in controlling gene expression at the transcriptional level.
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Schwarze F, Meraner J, Lechner M, Loidl A, Stasyk T, Laich A, Loidl P. Cell cycle-dependent acetylation of Rb2/p130 in NIH3T3 cells. Oncogene 2010; 29:5755-60. [PMID: 20676144 PMCID: PMC3007177 DOI: 10.1038/onc.2010.311] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The retinoblastoma protein (pRb) and the pRb-related proteins, p130 and p107, form the 'pocket protein' family of cell cycle regulatory factors. A well characterized function of these proteins is the cell cycle-dependent regulation of E2F-responsive genes. The biological activity of pocket proteins is regulated by phosphorylation and for the founding member pRb it has been shown that acetylation also has an important role in modulating its function during the cell cycle. Here, we show that hyperphosphorylated retinoblastoma 2 (Rb2)/p130 also exists in an acetylated form in NIH3T3 cells. Acetylated p130 is present in the nucleus but not in the cytoplasm. Acetylation is cell cycle dependent, starting in S-phase and persisting until late G(2)-period. Using recombinant p130 and truncated forms for in vitro acetylation by the acetyltransferase p300, we could identify K1079 in the C-terminal part as the major acetylation site by mass spectrometry. Minor acetylation sites were pinpointed to K1068 and K1111 in the C-terminus, and K128 and K130 in the N-terminus. The human papilloma virus 16 protein-E7 preferentially binds to acetylated p130 and significantly increases in vitro p130 acetylation by p300.
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Affiliation(s)
- F Schwarze
- Division of Molecular Biology, Biocenter, Innsbruck Medical University, Innsbruck, Austria
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34
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Merkel cell polyomavirus-infected Merkel cell carcinoma cells require expression of viral T antigens. J Virol 2010; 84:7064-72. [PMID: 20444890 DOI: 10.1128/jvi.02400-09] [Citation(s) in RCA: 333] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Merkel cell carcinoma (MCC) is the most aggressive skin cancer. Recently, it was demonstrated that human Merkel cell polyomavirus (MCV) is clonally integrated in approximately 80% of MCC tumors. However, direct evidence for whether oncogenic viral proteins are needed for the maintenance of MCC cells is still missing. To address this question, we knocked down MCV T-antigen (TA) expression in MCV-positive MCC cell lines using three different short hairpin RNA (shRNA)-expressing vectors targeting exon 1 of the TAs. The MCC cell lines used include three newly generated MCV-infected cell lines and one MCV-negative cell line from MCC tumors. Notably, all MCV-positive MCC cell lines underwent growth arrest and/or cell death upon TA knockdown, whereas the proliferation of MCV-negative cell lines remained unaffected. Despite an increase in the number of annexin V-positive, 7-amino-actinomycin D (7-AAD)-negative cells upon TA knockdown, activation of caspases or changes in the expression and phosphorylation of Bcl-2 family members were not consistently detected after TA suppression. Our study provides the first direct experimental evidence that TA expression is necessary for the maintenance of MCV-positive MCC and that MCV is the infectious cause of MCV-positive MCC.
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35
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Gualco E, Urbanska K, Perez-Liz G, Sweet T, Peruzzi F, Reiss K, Del Valle L. IGF-IR-dependent expression of Survivin is required for T-antigen-mediated protection from apoptosis and proliferation of neural progenitors. Cell Death Differ 2009; 17:439-51. [PMID: 19834489 PMCID: PMC2822053 DOI: 10.1038/cdd.2009.146] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The Insulin-like Growth Factor-1 Receptor (IGF-IR) and the human polyomavirus JCV protein, T-Antigen cooperate in the transformation of neuronal precursors in the cerebellum, which may be a contributing factor in the development of brain tumors. Since it is not clear why T-Antigen requires IGF-IR for transformation, we investigated this process in neural progenitors from IGF-IR knockout embryos (ko-IGF-IR) and from their wild type non-transgenic littermates (wt-IGF-IR). In contrast to wt-IGF-IR, the brain and dorsal root ganglia of ko-IGF-IR embryos showed low levels of the anti-apoptotic protein Survivin, accompanied by elevated numbers of apoptotic neurons and an earlier differentiation phenotype. In wt-IGF-IR neural progenitors in vitro, induction of T-Antigen expression tripled the expression of Survivin, and accelerated cell proliferation. In ko-IGF-IR progenitors induction of T-Antigen failed to increase Survivin, resulting in massive apoptosis. Importantly, ectopic expression of Survivin protected ko-IGF-IR progenitor cells from apoptosis and siRNA inhibition of Survivin activated apoptosis in wt-IGF-IR progenitors expressing T-Antigen. Our results indicate that reactivation of the anti-apoptotic Survivin may be a critical step in JCV T-Antigen induced transformation, which in neural progenitors requires IGF-IR.
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Affiliation(s)
- E Gualco
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Philadelphia, PA, USA
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36
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Chaurushiya MS, Weitzman MD. Viral manipulation of DNA repair and cell cycle checkpoints. DNA Repair (Amst) 2009; 8:1166-76. [PMID: 19473887 DOI: 10.1016/j.dnarep.2009.04.016] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Recognition and repair of DNA damage is critical for maintaining genomic integrity and suppressing tumorigenesis. In eukaryotic cells, the sensing and repair of DNA damage are coordinated with cell cycle progression and checkpoints, in order to prevent the propagation of damaged DNA. The carefully maintained cellular response to DNA damage is challenged by viruses, which produce a large amount of exogenous DNA during infection. Viruses also express proteins that perturb cellular DNA repair and cell cycle pathways, promoting tumorigenesis in their quest for cellular domination. This review presents an overview of strategies employed by viruses to manipulate DNA damage responses and cell cycle checkpoints as they commandeer the cell to maximize their own viral replication. Studies of viruses have identified key cellular regulators and revealed insights into molecular mechanisms governing DNA repair, cell cycle checkpoints, and transformation.
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Affiliation(s)
- Mira S Chaurushiya
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA 92037, USA
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37
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Russo G, Anzivino E, Fioriti D, Mischitelli M, Bellizzi A, Giordano A, Autran-Gomez A, Di Monaco F, Di Silverio F, Sale P, Di Prospero L, Pietropaolo V. p53 gene mutational rate, Gleason score, and BK virus infection in prostate adenocarcinoma: Is there a correlation? J Med Virol 2008; 80:2100-7. [PMID: 19040285 DOI: 10.1002/jmv.21312] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Prostate cancer represents the second leading cause of cancer deaths in Western countries. Viral infections could play a role in prostate carcinogenesis. Human polyomavirus BK (BKV) is a possible candidate because of its transforming properties. In this study, BKV sequences in urine, blood, fresh, and paraffin-embedded prostate cancer samples from 26 patients were searched using Q-PCR analysis. T antigen (TAg) and p53 localization in neoplastic cells were evaluated by immunohistochemical analysis. Also, the presence of mutations in 5-9 exons of p53 gene was analyzed. Results showed that BKV-DNA was found in urine (54%), plasma (31%), and in fresh prostate cancer specimens (85%). The analysis of p53 gene evidenced several mutations in high Gleason patients, according to tumor advanced stage. Immunohistochemical analysis results evidenced the localization of p53 and TAg into cytoplasm, whereas in TAg-negative tumors, p53 was nuclear. This study suggests that BKV acts as cofactor in the pathogenesis of prostate cancer. These observations emphasize previous studies regarding the cellular pathways that may be deregulated by BKV.
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Affiliation(s)
- Giuseppe Russo
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania
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38
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Zurawski DV, Mumy KL, Faherty CS, McCormick BA, Maurelli AT. Shigella flexneri type III secretion system effectors OspB and OspF target the nucleus to downregulate the host inflammatory response via interactions with retinoblastoma protein. Mol Microbiol 2008; 71:350-68. [PMID: 19017275 DOI: 10.1111/j.1365-2958.2008.06524.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OspF, OspG and IpaH(9.8) are type III secretion system (T3SS) effectors of Shigella flexneri that downregulate the host innate immune response. OspF modifies mitogen-activated protein kinase pathways and polymorphonuclear leucocyte transepithelial migration associated with Shigella invasion. OspF also localizes in the nucleus to mediate chromatin remodelling, resulting in reduced transcription of inflammatory cytokines. We now report that OspB can be added to the set of S. flexneri T3SS effectors required to modulate the innate immune response. T84 cells infected with a Delta ospB mutant resulted in reduced polymorphonuclear leucocyte transepithelial migration and mitogen-activated protein kinase signalling. Tagged versions of OspB localized with endosomes and the nucleus. Further, T84 cells infected with the Delta ospB mutant showed increased levels of secreted IL-8 compared with wild-type infected cells. Both GST-OspB and GST-OspF coprecipitated retinoblastoma protein from host cell lysates. Because Delta ospB and Delta ospF mutants share similar phenotypes, and OspB and OspF share a host binding partner, we propose that OspB and OspF facilitate the remodelling of chromatin via interactions with retinoblastoma protein, resulting in diminished inflammatory cytokine production. The requirement of multiple T3SS effectors to modulate the innate immune response correlates to the complexity of the human immune system.
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Affiliation(s)
- Daniel V Zurawski
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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39
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Del Valle L, White MK, Khalili K. Potential mechanisms of the human polyomavirus JC in neural oncogenesis. J Neuropathol Exp Neurol 2008; 67:729-40. [PMID: 18648329 PMCID: PMC2771681 DOI: 10.1097/nen.0b013e318180e631] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The human polyomavirus JC (JCV) is a small DNA tumor virus and the etiologic agent of the progressive multifocal leukoencephalopathy. In progressive multifocal leukoencephalopathy, active JCV replication causes the lytic destruction of oligodendrocytes. The normal immune system prevents JCV replication and suppresses the virus into a state of latency so that expression of viral proteins cannot be detected. In a cellular context that is nonpermissive for viral replication, JCV can affect oncogenic transformation. For example, JCV is highly tumorigenic when inoculated into experimental animals, including rodents and monkeys. In these animal tumors, there is expression of early T-antigen but not of late capsid proteins, nor is there viral replication. Moreover, mice transgenic for JCV T-antigen alone develop tumors of neural tube origin. Detection of JCV genomic sequences and expression of viral T-antigen and agnoprotein suggest a possible association of this virus with a variety of human brain and non-CNS tumors. Here, we discuss the mechanisms involved in JCV oncogenesis, briefly review studies that do and do not support a causative role for this virus in human CNS tumors, and identify key issues for future research.
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Affiliation(s)
- Luis Del Valle
- Department of Neuroscience, Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania 19122, USA
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40
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Kmieciak D, Dębicki S, Trzeciak WH. Occurrence rate and genotype distribution of the JC virus (JCV) in a sample from the Polish population. J Med Virol 2008; 80:1079-83. [DOI: 10.1002/jmv.21153] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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41
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Caracciolo V, Reiss K, Crozier-Fitzgerald C, De Pascali F, Macaluso M, Khalili K, Giordano A, Claudio PP. Interplay between the retinoblastoma related pRb2/p130 and E2F-4 and -5 in relation to JCV-TAg. J Cell Physiol 2007; 212:96-104. [PMID: 17385710 DOI: 10.1002/jcp.21005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Human polyomaviruses, which include JC virus (JCV) and BK virus (BKV), as well as the simian virus 40 (SV40), have been associated with human tumors and have been shown to be highly tumorigenic in experimental animal models. Although the mechanism by which JCV induces tumorigenesis is not entirely clear, earlier studies point to the involvement of the viral early protein T-antigen which has the ability to bind and inactivate tumor suppressors and cell cycle regulatory proteins, such as the retinoblastoma family proteins and p53. We investigated if the distribution between nucleus and cytoplasm of the transcription factors E2F4 and E2F5 is mediated by pRb2/p130 and if the presence of JCV T-antigen may impair this shuttling by sequestering pRb2/p130. The results showed that E2F4 was prevalently localized in the nucleus of both T-antigen positive and -negative R503 cells independently of the cell cycle phase. E2F5 instead was prevalently localized in the cytoplasmic fraction in G(0)/G(1), S-phase synchronized, and asynchronous R503 and R503 T-Ag positive cells. The presence of T-antigen did not influence the subcellular localization of these transcription factors E2F4 and E2F5, at least in this murine cellular model. Moreover, Small interference RNA experiments directed toward silencing the Rb2/p130 gene demonstrated that pRb2/p130 does not play a predominant role in the nuclear transportation of E2F4 and E2F5.
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Affiliation(s)
- Valentina Caracciolo
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, College of Science and Technology, Temple University, Philadelphia, Pennsylvania 19122, USA
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