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Catalán-Tatjer D, Tzimou K, Nielsen LK, Lavado-García J. Unravelling the essential elements for recombinant adeno-associated virus (rAAV) production in animal cell-based platforms. Biotechnol Adv 2024; 73:108370. [PMID: 38692443 DOI: 10.1016/j.biotechadv.2024.108370] [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: 01/16/2024] [Revised: 04/05/2024] [Accepted: 04/27/2024] [Indexed: 05/03/2024]
Abstract
Recombinant adeno-associated viruses (rAAVs) stand at the forefront of gene therapy applications, holding immense significance for their safe and efficient gene delivery capabilities. The constantly increasing and unmet demand for rAAVs underscores the need for a more comprehensive understanding of AAV biology and its impact on rAAV production. In this literature review, we delved into AAV biology and rAAV manufacturing bioprocesses, unravelling the functions and essentiality of proteins involved in rAAV production. We discuss the interconnections between these proteins and how they affect the choice of rAAV production platform. By addressing existing inconsistencies, literature gaps and limitations, this review aims to define a minimal set of genes that are essential for rAAV production, providing the potential to advance rAAV biomanufacturing, with a focus on minimizing the genetic load within rAAV-producing cells.
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Affiliation(s)
- David Catalán-Tatjer
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Konstantina Tzimou
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark
| | - Lars K Nielsen
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark; Australian Institute for Bioengineering and Nanotechnology, University of Queensland, Australia
| | - Jesús Lavado-García
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Denmark.
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2
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Lin YC, Lu M, Cai W, Hu WS. Comparative transcriptomic and proteomic kinetic analysis of adeno-associated virus production systems. Appl Microbiol Biotechnol 2024; 108:385. [PMID: 38896252 PMCID: PMC11186941 DOI: 10.1007/s00253-024-13203-5] [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: 02/29/2024] [Revised: 05/20/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024]
Abstract
Recombinant adeno-associated virus (rAAV) is a major gene delivery vehicle. We have constructed a stable rAAV producer cell line by integrating essential rAAV genome, viral and helper genes into the genome of HEK293 cell under the control of inducible promoters. Upon induction, the cell line produces transducing rAAV. To gain insight into enhancing rAAV productivity and vector quality, we performed a comparative transcriptomic and proteomic analysis of our synthetic cell line GX2 and two wild-type AAV (wtAAV) production systems, one by virus co-infection and the other by multi-plasmid transfection. The three systems had different kinetics in viral component synthesis but generated comparable copies of AAV genomes; however, the capsid titer of GX2 was an order of magnitude lower compared to those two wtAAV systems, indicating that its capsid production may be insufficient. The genome packaging efficiency was also lower in GX2 despite it produced higher levels of Rep52 proteins than either wtAAV systems, suggesting that Rep52 protein expression may not limit genome packaging. In the two wtAAV systems, VP were the most abundant AAV proteins and their levels continued to increase, while GX2 had high level of wasteful cargo gene expression. Furthermore, upregulated inflammation, innate immune responses, and MAPK signaling, as well as downregulated mitochondrial functions, were commonly observed in either rAAV or wtAAV systems. Overall, this comparative multi-omics study provided rich insights into host cell and viral factors that are potential targets for genetic and process intervention to enhance the productivity of synthetic rAAV producer cell lines. KEY POINTS: • wtAAV infection was more efficient in producing full viral particles than the synthetic cell GX2. • Capsid protein synthesis, genome replication, and packaging may limit rAAV production in GX2. • wtAAV infection and rAAV production in GX2 elicited similar host cell responses.
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Affiliation(s)
- Yu-Chieh Lin
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue S.E, Minneapolis, MN, 55455-0132, USA
| | - Min Lu
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue S.E, Minneapolis, MN, 55455-0132, USA
| | - Wen Cai
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue S.E, Minneapolis, MN, 55455-0132, USA
| | - Wei-Shou Hu
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue S.E, Minneapolis, MN, 55455-0132, USA.
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3
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Göttig L, Schreiner S. E4orf1: The triple agent of adenovirus - Unraveling its roles in oncogenesis, infectious obesity and immune responses in virus replication and vector therapy. Tumour Virus Res 2024; 17:200277. [PMID: 38428735 PMCID: PMC10937242 DOI: 10.1016/j.tvr.2024.200277] [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: 01/22/2024] [Revised: 02/20/2024] [Accepted: 02/20/2024] [Indexed: 03/03/2024] Open
Abstract
Human Adenoviruses (HAdV) are nearly ubiquitous pathogens comprising numerous sub-types that infect various tissues and organs. Among many encoded proteins that facilitate viral replication and subversion of host cellular processes, the viral E4orf1 protein has emerged as an intriguing yet under-investigated player in the complex interplay between the virus and its host. E4orf1 has gained attention as a metabolism activator and oncogenic agent, while recent research is showing that E4orf1 may play a more important role in modulating cellular pathways such as PI3K-Akt-mTOR, Ras, the immune response and further HAdV replication stages than previously anticipated. In this review, we aim to explore the structure, molecular mechanisms, and biological functions of E4orf1, shedding light on its potentially multifaceted roles during HAdV infection, including metabolic diseases and oncogenesis. Furthermore, we discuss the role of functional E4orf1 in biotechnological applications such as Adenovirus (AdV) vaccine vectors and oncolytic AdV. By dissecting the intricate relationships between HAdV types and E4orf1 proteins, this review provides valuable insights into viral pathogenesis and points to promising areas of future research.
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Affiliation(s)
- Lilian Göttig
- Institute of Virology, School of Medicine, Technical University of Munich, Germany
| | - Sabrina Schreiner
- Institute of Virology, School of Medicine, Technical University of Munich, Germany; Institute of Virology, Hannover Medical School, Hannover, Germany; Cluster of Excellence RESIST (Resolving Infection Susceptibility; EXC 2155), Hannover, Germany; Institute of Virology, Medical Center - University of Freiburg, Freiburg, Germany.
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4
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Göttig L, Jummer S, Staehler L, Groitl P, Karimi M, Blanchette P, Kosulin K, Branton PE, Schreiner S. The human adenovirus PI3K-Akt activator E4orf1 is targeted by the tumor suppressor p53. J Virol 2024; 98:e0170123. [PMID: 38451084 PMCID: PMC11019960 DOI: 10.1128/jvi.01701-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/13/2024] [Indexed: 03/08/2024] Open
Abstract
Human adenoviruses (HAdV) are classified as DNA tumor viruses due to their potential to mediate oncogenic transformation in non-permissive mammalian cells and certain human stem cells. To achieve transformation, the viral early proteins of the E1 and E4 regions must block apoptosis and activate proliferation: the former predominantly through modulating the cellular tumor suppressor p53 and the latter by activating cellular pro-survival and pro-metabolism protein cascades, such as the phosphoinositide 3-kinase (PI3K-Akt) pathway, which is activated by HAdV E4orf1. Focusing on HAdV-C5, we show that E4orf1 is necessary and sufficient to stimulate Akt activation through phosphorylation in H1299 cells, which is not only hindered but repressed during HAdV-C5 infection with a loss of E4orf1 function in p53-positive A549 cells. Contrary to other research, E4orf1 localized not only in the common, cytoplasmic PI3K-Akt-containing compartment, but also in distinct nuclear aggregates. We identified a novel inhibitory mechanism, where p53 selectively targeted E4orf1 to destabilize it, also stalling E4orf1-dependent Akt phosphorylation. Co-IP and immunofluorescence studies showed that p53 and E4orf1 interact, and since p53 is bound by the HAdV-C5 E3 ubiquitin ligase complex, we also identified E4orf1 as a novel factor interacting with E1B-55K and E4orf6 during infection; overexpression of E4orf1 led to less-efficient E3 ubiquitin ligase-mediated proteasomal degradation of p53. We hypothesize that p53 specifically subverts the pro-survival function of E4orf1-mediated PI3K-Akt activation to protect the cell from metabolic hyper-activation or even transformation.IMPORTANCEHuman adenoviruses (HAdV) are nearly ubiquitous pathogens comprising numerous subtypes that infect various tissues and organs. Among many encoded proteins that facilitate viral replication and subversion of host cellular processes, the viral E4orf1 protein has emerged as an intriguing yet under-investigated player in the complex interplay between the virus and its host. Nonetheless, E4orf1 has gained attention as a metabolism activator and oncogenic agent, while recent research is showing that E4orf1 may play a more important role in modulating the cellular pathways such as phosphoinositide 3-kinase-Akt-mTOR. Our study reveals a novel and general impact of E4orf1 on host mechanisms, providing a novel basis for innovative antiviral strategies in future therapeutic settings. Ongoing investigations of the cellular pathways modulated by HAdV are of great interest, particularly since adenovirus-based vectors actually serve as vaccine or gene vectors. HAdV constitute an ideal model system to analyze the underlying molecular principles of virus-induced tumorigenesis.
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Affiliation(s)
- Lilian Göttig
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Simone Jummer
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Luisa Staehler
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Peter Groitl
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Maryam Karimi
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Paola Blanchette
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- Goodman Cancer Research Center, McGill University, Montreal, Quebec, Canada
| | - Karin Kosulin
- Molecular Microbiology, Children’s Cancer Research Institute, Vienna, Austria
| | - Philip E. Branton
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- Goodman Cancer Research Center, McGill University, Montreal, Quebec, Canada
| | - Sabrina Schreiner
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Virology, Hannover Medical School, Hannover, Germany
- Cluster of Excellence RESIST (Resolving Infection Susceptibility; EXC 2155), Freiburg, Germany
- Institute of Virology, Medical Center—University of Freiburg, Freiburg, Germany
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5
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Khalid T, Hasan A, Fatima JE, Faridi SA, Khan AF, Mir SS. Therapeutic role of mTOR inhibitors in control of SARS-CoV-2 viral replication. Mol Biol Rep 2023; 50:2701-2711. [PMID: 36538171 PMCID: PMC9764303 DOI: 10.1007/s11033-022-08188-1] [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: 09/06/2022] [Accepted: 12/07/2022] [Indexed: 12/24/2022]
Abstract
By the end of 2019, COVID-19 was reported in Wuhan city of China, and through human-human transmission, this virus spread worldwide and became a pandemic. Initial symptoms of the disease include fever, cough, loss of smell, taste, and shortness of breath, but a decrease in the oxygen levels in the body leads, and pneumonia may ultimately lead to the patient's death. However, the symptoms vary from patient to patient. To understand COVID-19 disease pathogenesis, researchers have tried to understand the cellular pathways that could be targeted to suppress viral replication. Thus, this article reviews the markers that could be targeted to inhibit viral replication by inhibiting the translational initiation complex/regulatory kinases and upregulating host autophagic flux that may lead to a reduction in the viral load. The article also highlights that mTOR inhibitors may act as potential inhibitors of viral replication. mTOR inhibitors such as metformin may inhibit the interaction of SARS-CoV-2 Nsp's and ORFs with mTORC1, LARP1, and 4E-BP. They may also increase autophagic flux by decreasing protein degradation via inhibition of Skp2, further promoting viral cell death. These events result in cell cycle arrest at G1 by p27, ultimately causing cell death.
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Affiliation(s)
- Tuba Khalid
- Department of Bioengineering, Faculty of Engineering, Integral University, Kursi Road, 226026, Lucknow, India
| | - Adria Hasan
- Department of Bioengineering, Faculty of Engineering, Integral University, Kursi Road, 226026, Lucknow, India
- Molecular Cell Biology Laboratory, Integral Information and Research Centre-4 (IIRC-4), Integral University, Kursi Road, 226026, Lucknow, India
| | - Jamal E Fatima
- Department of Bioengineering, Faculty of Engineering, Integral University, Kursi Road, 226026, Lucknow, India
| | - Soban Ahmad Faridi
- Department of Bioengineering, Faculty of Engineering, Integral University, Kursi Road, 226026, Lucknow, India
| | - Ahamad Faiz Khan
- Department of Bioengineering, Faculty of Engineering, Integral University, Kursi Road, 226026, Lucknow, India
| | - Snober S Mir
- Molecular Cell Biology Laboratory, Integral Information and Research Centre-4 (IIRC-4), Integral University, Kursi Road, 226026, Lucknow, India.
- Department of Biosciences, Faculty of Science, Integral University, Kursi Road, 226026, Lucknow, Uttar Pradesh, India.
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6
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Mullen PJ, Christofk HR. The Metabolic Relationship Between Viral Infection and Cancer. ANNUAL REVIEW OF CANCER BIOLOGY 2022. [DOI: 10.1146/annurev-cancerbio-070120-090423] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Viruses are fundamental tools in cancer research. They were used to discover the first oncogenes in the 1970s, and they are now being modified for use as antitumor therapeutics. Key to both of these oncogenic and oncolytic properties is the ability of viruses to rewire host cell metabolism. In this review, we describe how viral oncogenes alter metabolism to increase the synthesis of macromolecules necessary for both viral replication and tumor growth. We then describe how understanding the specific metabolic requirements of virus-infected cells can help guide strategies to improve the efficacy of oncolytic viruses, and we highlight immunometabolism and tumor microenvironment research that could also increase the therapeutic benefits of oncolytic viruses. We also describe how studies describing the therapeutic effects of dietary nutrient restriction in cancer can suggest new avenues for research into antiviral therapeutics.
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Affiliation(s)
- Peter J. Mullen
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Heather R. Christofk
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, California, USA
- Jonsson Comprehensive Cancer Center and Eli and Edythe Broad Stem Cell Research Center, University of California, Los Angeles, California, USA
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7
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Sangare K, Helmold Hait S, Moore M, Hogge C, Hoang T, Rahman MA, Venzon DJ, LaBranche C, Montefiori D, Robert-Guroff M, Thomas MA. E4orf1 Suppresses E1B-Deleted Adenovirus Vaccine-Induced Immune Responses. Vaccines (Basel) 2022; 10:vaccines10020295. [PMID: 35214753 PMCID: PMC8875587 DOI: 10.3390/vaccines10020295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 02/11/2022] [Accepted: 02/12/2022] [Indexed: 01/27/2023] Open
Abstract
As demonstrated by the recent COVID pandemic, vaccines can reduce the burden arising from infectious agents. Adenoviruses (Ads) with deletion of the early region 1B55K (ΔE1B Ad) are currently being explored for use in vaccine delivery. ΔE1B Ads are different from Ads with deletions in early region 1 and early region 3 (ΔE1/E3) used in most Ad vaccine vectors in that they contain the Ad early region 1A (E1A), and therefore the ability to replicate. Common to almost all Ads that are being explored for clinical use is the Ad early region 4 (E4). Among the E4 genes is open reading frame 1 (E4orf1), which mediates signals through the PI3-kinase/Akt pathway that is known to modulate immune responses. This suggests that E4orf1 might also modulate immune responses, although it has remained unexplored in ΔE1B Ad. Here, we show that cells infected with an E1B55K and E4orf1-deleted (ΔE41) Ad exhibited reduced levels of phosphorylated Akt (Ser473 and Thr308)) and expressed different intrinsic innate immune cytokines from those induced in cells infected with an E4orf1-containing, ΔE1B parental Ad that exhibited elevated levels of phosphorylated Akt. Rhesus macaques immunized with a ΔE41 Ad that expressed rhFLSC (HIV-1BaL gp120 linked to rhesus CD4 D1 and D2), exhibited higher levels of rhFLSC-specific interferon γ-producing memory T-cells, higher titers of rhFLSC-specific IgG1 binding antibody in serum, and antibodies able to mediate antibody-dependent cellular cytotoxicity (ADCC) with greater killing capacity than the ΔE1B Ad. Therefore, E4orf1, perhaps by acting through the PI3-kinase/Akt pathway, limits intrinsic innate and system-wide adaptive immune responses that are important for improved ΔE1B Ad-based vaccines.
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Affiliation(s)
- Kotou Sangare
- Department of Biology, Howard University, Washington, DC 20059, USA; (K.S.); (M.M.)
- Section on Immune Biology of Retroviral Infection, Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.H.H.); (C.H.); (T.H.); (M.A.R.); (M.R.-G.)
| | - Sabrina Helmold Hait
- Section on Immune Biology of Retroviral Infection, Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.H.H.); (C.H.); (T.H.); (M.A.R.); (M.R.-G.)
| | - Madison Moore
- Department of Biology, Howard University, Washington, DC 20059, USA; (K.S.); (M.M.)
| | - Christopher Hogge
- Section on Immune Biology of Retroviral Infection, Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.H.H.); (C.H.); (T.H.); (M.A.R.); (M.R.-G.)
| | - Tanya Hoang
- Section on Immune Biology of Retroviral Infection, Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.H.H.); (C.H.); (T.H.); (M.A.R.); (M.R.-G.)
| | - Mohammad Arif Rahman
- Section on Immune Biology of Retroviral Infection, Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.H.H.); (C.H.); (T.H.); (M.A.R.); (M.R.-G.)
| | - David J. Venzon
- Biostatistics and Data Management Section, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Celia LaBranche
- Duke University Medical Center, Durham, NC 27710, USA; (C.L.); (D.M.)
| | - David Montefiori
- Duke University Medical Center, Durham, NC 27710, USA; (C.L.); (D.M.)
| | - Marjorie Robert-Guroff
- Section on Immune Biology of Retroviral Infection, Vaccine Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; (S.H.H.); (C.H.); (T.H.); (M.A.R.); (M.R.-G.)
| | - Michael A. Thomas
- Department of Biology, Howard University, Washington, DC 20059, USA; (K.S.); (M.M.)
- Correspondence: ; Tel.: +1-202-806-6941
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8
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Burgess HM, Vink EI, Mohr I. Minding the message: tactics controlling RNA decay, modification, and translation in virus-infected cells. Genes Dev 2022; 36:108-132. [PMID: 35193946 PMCID: PMC8887129 DOI: 10.1101/gad.349276.121] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
With their categorical requirement for host ribosomes to translate mRNA, viruses provide a wealth of genetically tractable models to investigate how gene expression is remodeled post-transcriptionally by infection-triggered biological stress. By co-opting and subverting cellular pathways that control mRNA decay, modification, and translation, the global landscape of post-transcriptional processes is swiftly reshaped by virus-encoded factors. Concurrent host cell-intrinsic countermeasures likewise conscript post-transcriptional strategies to mobilize critical innate immune defenses. Here we review strategies and mechanisms that control mRNA decay, modification, and translation in animal virus-infected cells. Besides settling infection outcomes, post-transcriptional gene regulation in virus-infected cells epitomizes fundamental physiological stress responses in health and disease.
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Affiliation(s)
- Hannah M Burgess
- Department of Microbial Sciences, School of Biosciences and Medicine, University of Surrey, Guildford GU2 7XH, United Kingdom
| | - Elizabeth I Vink
- Department of Microbiology, New York University School of Medicine, New York, New York 10016, USA
| | - Ian Mohr
- Department of Microbiology, New York University School of Medicine, New York, New York 10016, USA.,Laura and Isaac Perlmutter Cancer Institute, New York University School of Medicine, New York, New York 10016, USA
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9
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Mullen PJ, Garcia G, Purkayastha A, Matulionis N, Schmid EW, Momcilovic M, Sen C, Langerman J, Ramaiah A, Shackelford DB, Damoiseaux R, French SW, Plath K, Gomperts BN, Arumugaswami V, Christofk HR. SARS-CoV-2 infection rewires host cell metabolism and is potentially susceptible to mTORC1 inhibition. Nat Commun 2021; 12:1876. [PMID: 33767183 PMCID: PMC7994801 DOI: 10.1038/s41467-021-22166-4] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/03/2021] [Indexed: 12/18/2022] Open
Abstract
Viruses hijack host cell metabolism to acquire the building blocks required for replication. Understanding how SARS-CoV-2 alters host cell metabolism may lead to potential treatments for COVID-19. Here we profile metabolic changes conferred by SARS-CoV-2 infection in kidney epithelial cells and lung air-liquid interface (ALI) cultures, and show that SARS-CoV-2 infection increases glucose carbon entry into the TCA cycle via increased pyruvate carboxylase expression. SARS-CoV-2 also reduces oxidative glutamine metabolism while maintaining reductive carboxylation. Consistent with these changes, SARS-CoV-2 infection increases the activity of mTORC1 in cell lines and lung ALI cultures. Lastly, we show evidence of mTORC1 activation in COVID-19 patient lung tissue, and that mTORC1 inhibitors reduce viral replication in kidney epithelial cells and lung ALI cultures. Our results suggest that targeting mTORC1 may be a feasible treatment strategy for COVID-19 patients, although further studies are required to determine the mechanism of inhibition and potential efficacy in patients.
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Affiliation(s)
- Peter J Mullen
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Gustavo Garcia
- Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, CA, USA
| | - Arunima Purkayastha
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Nedas Matulionis
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Ernst W Schmid
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Milica Momcilovic
- Department of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Chandani Sen
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Justin Langerman
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
| | - Arunachalam Ramaiah
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA, USA
| | - David B Shackelford
- Department of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
| | - Robert Damoiseaux
- Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
- California Nanosystems Institute, UCLA, Los Angeles, CA, USA
- Department of Bioengineering, UCLA Samueli School of Engineering, Los Angeles, CA, USA
- Department of Molecular Biology Interdepartmental Program, UCLA, Los Angeles, CA, USA
| | - Samuel W French
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - Kathrin Plath
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA
- Department of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
- Department of Molecular Biology Interdepartmental Program, UCLA, Los Angeles, CA, USA
- Eli and Edythe Broad Stem Cell Research Center, UCLA, Los Angeles, CA, USA
| | - Brigitte N Gomperts
- UCLA Children's Discovery and Innovation Institute, Mattel Children's Hospital UCLA, Department of Pediatrics, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
- Department of Pulmonary and Critical Care Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
- Department of Molecular Biology Interdepartmental Program, UCLA, Los Angeles, CA, USA
- Eli and Edythe Broad Stem Cell Research Center, UCLA, Los Angeles, CA, USA
| | - Vaithilingaraja Arumugaswami
- Department of Molecular and Medical Pharmacology, UCLA, Los Angeles, CA, USA
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA
| | - Heather R Christofk
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles (UCLA), Los Angeles, CA, USA.
- Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, CA, USA.
- Eli and Edythe Broad Stem Cell Research Center, UCLA, Los Angeles, CA, USA.
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10
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Mechanistic Target of Rapamycin Signaling Activation Antagonizes Autophagy To Facilitate Zika Virus Replication. J Virol 2020; 94:JVI.01575-20. [PMID: 32878890 DOI: 10.1128/jvi.01575-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 08/25/2020] [Indexed: 12/11/2022] Open
Abstract
Zika virus (ZIKV), a mosquito-transmitted flavivirus, is linked to microcephaly and other neurological defects in neonates and Guillain-Barré syndrome in adults. The molecular mechanisms regulating ZIKV infection and pathogenic outcomes are incompletely understood. Signaling by the mechanistic (mammalian) target of rapamycin (mTOR) kinase is important for cell survival and proliferation, and viruses are known to hijack this pathway for their replication. Here, we show that in human neuronal precursors and glial cells in culture, ZIKV infection activates both mTOR complex 1 (mTORC1) and mTORC2. Inhibition of mTOR kinase by Torin1 or rapamycin results in reduction in ZIKV protein expression and progeny production. Depletion of Raptor, the defining subunit of mTORC1, by small interfering RNA (siRNA) negatively affects ZIKV protein expression and viral replication. Although depletion of Rictor, the unique subunit of mTORC2, or the mTOR kinase itself also inhibits the viral processes, the extent of inhibition is less pronounced. Autophagy is transiently induced early by ZIKV infection, and impairment of autophagosome elongation by the class III phosphatidylinositol 3-kinase (PI3K) inhibitor 3-methyladenine (3-MA) enhances viral protein accumulation and progeny production. mTOR phosphorylates and inactivates ULK1 (S757) at later stages of ZIKV infection, suggesting a link between autophagy inhibition and mTOR activation by ZIKV. Accordingly, inhibition of ULK1 (by MRT68921) or autophagy (by 3-MA) reversed the effects of mTOR inhibition, leading to increased levels of ZIKV protein expression and progeny production. Our results demonstrate that ZIKV replication requires the activation of both mTORC1 and mTORC2, which negatively regulates autophagy to facilitate ZIKV replication.IMPORTANCE The re-emergence of Zika virus (ZIKV) and its association with neurological complications necessitates studies on the molecular mechanisms that regulate ZIKV pathogenesis. The mTOR signaling cascade is tightly regulated and central to normal neuronal development and survival. Disruption of mTOR signaling can result in neurological abnormalities. In the studies reported here, we demonstrate for the first time that ZIKV infection results in activation of both mTORC1 and mTORC2 to promote virus replication. Although autophagy is activated early in infection to counter virus replication, it is subsequently suppressed by mTOR. These results reveal critical roles of mTOR signaling and autophagy in ZIKV infection and point to a possible mechanism underlying ZIKV-induced pathogenesis. Elucidating the role of mTOR signaling in ZIKV infection will provide insights into the mechanisms of ZIKV-induced neurological complications and potential targets for therapeutic approaches.
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Salmona M, Feghoul L, Mercier-Delarue S, Diaz E, Splitberger M, Armero A, Dalle JH, Dutrieux J, LeGoff J. Effect of brincidofovir on adenovirus and A549 cells transcriptome profiles. Antiviral Res 2020; 182:104872. [PMID: 32768412 DOI: 10.1016/j.antiviral.2020.104872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Human adenovirus (HAdV) infections are associated with a high morbidity and mortality in transplant patients requiring the use of antiviral treatments. Brincidofovir (BCV), a cytidine analog, inhibits HAdV replication through viral DNA elongation termination and likely through other mechanisms. To elucidate if BCV regulates cellular antiviral pathways, we analyzed its impact on HAdV-infected and non-HAdV-infected lung epithelial cells. METHODS We assessed the cellular and viral transcriptome of A549 cells infected and non-infected with HAdV C5 and treated or non-treated with BCV by RNAseq after 72 h. RESULTS BCV treatment of HAdV infected cells resulted in a profound decrease of viral transcription associated with a relative overexpression of the early genes E1A and E4 and of the late gene L1. BCV had also a profound impact on A549 cells' transcriptome. Ontologic analysis revealed an effect of BCV on several pathways known to interact with adenovirus replication as mTor signalling and Wnt pathways. A549 cells treated with BCV demonstrated a significant inhibition of the biological function of "viral replication" including 25 dysregulated genes involved in inflammation pathways. CONCLUSION We demonstrated that BCV alters viral gene expression and promotes the expression of antiviral cellular pathways in A549 cells. These results provide new insights how to interfere with cellular pathways to control HAdV infections.
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Affiliation(s)
- Maud Salmona
- Université de Paris, INSERM U976, Insight Team, F-75010, Paris, France; Assistance-Publique des Hôpitaux de Paris, Microbiology Department, Virology Unit, Saint Louis Hospital, F-75010, Paris, France.
| | - Linda Feghoul
- Assistance-Publique des Hôpitaux de Paris, Microbiology Department, Virology Unit, Saint Louis Hospital, F-75010, Paris, France.
| | - Séverine Mercier-Delarue
- Assistance-Publique des Hôpitaux de Paris, Microbiology Department, Virology Unit, Saint Louis Hospital, F-75010, Paris, France.
| | - Elise Diaz
- Université de Paris, INSERM U976, Insight Team, F-75010, Paris, France.
| | - Marion Splitberger
- Assistance-Publique des Hôpitaux de Paris, Microbiology Department, Virology Unit, Saint Louis Hospital, F-75010, Paris, France.
| | - Alix Armero
- Université de Paris, INSERM U976, Insight Team, F-75010, Paris, France.
| | - Jean-Hugues Dalle
- Université de Paris, INSERM U976, Insight Team, F-75010, Paris, France; Assistance-Publique des Hôpitaux de Paris, Department of Pediatric Hemato-Immunology, Hospital Robert Debré, F-75019, Paris, France.
| | - Jacques Dutrieux
- Université de Paris, Institut Cochin, INSERM U1016, CNRS UMR8104, Paris, France.
| | - Jérôme LeGoff
- Université de Paris, INSERM U976, Insight Team, F-75010, Paris, France; Assistance-Publique des Hôpitaux de Paris, Microbiology Department, Virology Unit, Saint Louis Hospital, F-75010, Paris, France.
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Abstract
Both well-known and emerging viruses increasingly affect humans and cause disease, sometimes with devastating impact on society. The viruses present in the biosphere are the top predators in the life chain, virtually without enemies, except perhaps the immune system, and harsh environmental physicochemical conditions restricting their dissemination. We know a lot about viruses, but do we know enough? This series of reviews is dedicated to adenoviruses (AdVs), a family of nonenveloped DNA viruses occurring in vertebrates, including humans. AdVs have been the focus of intense research for more than 67 years. Besides causing disease, they have immensely contributed to the advance of life sciences and medicine over the past decades. Recently, AdVs have been widely used as vehicles in gene therapy and vaccination. They continue to provide fundamental insights into virus-host interactions in cells, tissues and organisms, as well as systems and metabolic networks. This special issue of FEBS Letters presents a unique collection of 23 state-of-the-art review articles by leading adenovirologists. In this prelude, I present the chapters, which provide a solid basis for further exploring the rich heritage in adenovirus molecular cell biology, structural biology, genetics, immunology, gene therapy and epidemiology. I conclude with an essential discussion of six blind spots in adenovirology.
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Affiliation(s)
- Urs F Greber
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
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Kleinberger T. Biology of the adenovirus E4orf4 protein: from virus infection to cancer cell death. FEBS Lett 2019; 594:1891-1917. [DOI: 10.1002/1873-3468.13704] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 11/24/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Tamar Kleinberger
- Department of Molecular Microbiology the Rappaport Faculty of Medicine Technion –Israel Institute of Technology Haifa Israel
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Cancer Treatment Goes Viral: Using Viral Proteins to Induce Tumour-Specific Cell Death. Cancers (Basel) 2019; 11:cancers11121975. [PMID: 31817939 PMCID: PMC6966515 DOI: 10.3390/cancers11121975] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/04/2019] [Accepted: 12/05/2019] [Indexed: 12/24/2022] Open
Abstract
Cell death is a tightly regulated process which can be exploited in cancer treatment to drive the killing of the tumour. Several conventional cancer therapies including chemotherapeutic agents target pathways involved in cell death, yet they often fail due to the lack of selectivity they have for tumour cells over healthy cells. Over the past decade, research has demonstrated the existence of numerous proteins which have an intrinsic tumour-specific toxicity, several of which originate from viruses. These tumour-selective viral proteins, although from distinct backgrounds, have several similar and interesting properties. Though the mechanism(s) of action of these proteins are not fully understood, it is possible that they can manipulate several cell death modes in cancer exemplifying the intricate interplay between these pathways. This review will discuss our current knowledge on the topic and outstanding questions, as well as deliberate the potential for viral proteins to progress into the clinic as successful cancer therapeutics.
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15
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Nebenzahl-Sharon K, Sharf R, Amer J, Shalata H, Khoury-Haddad H, Sohn SY, Ayoub N, Hearing P, Kleinberger T. An Interaction with PARP-1 and Inhibition of Parylation Contribute to Attenuation of DNA Damage Signaling by the Adenovirus E4orf4 Protein. J Virol 2019; 93:e02253-18. [PMID: 31315986 PMCID: PMC6744226 DOI: 10.1128/jvi.02253-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Accepted: 07/02/2019] [Indexed: 01/27/2023] Open
Abstract
The adenovirus (Ad) E4orf4 protein was reported to contribute to inhibition of ATM- and ATR-regulated DNA damage signaling during Ad infection and following treatment with DNA-damaging drugs. Inhibition of these pathways improved Ad replication, and when expressed alone, E4orf4 sensitized transformed cells to drug-induced toxicity. However, the mechanisms utilized were not identified. Here, we show that E4orf4 associates with the DNA damage sensor poly(ADP-ribose) polymerase 1 (PARP-1) and that the association requires PARP activity. During Ad infection, PARP is activated, but its activity is not required for recruitment of either E4orf4 or PARP-1 to virus replication centers, suggesting that their association occurs following recruitment. Inhibition of PARP-1 assists E4orf4 in reducing DNA damage signaling during infection, and E4orf4 attenuates virus- and DNA damage-induced parylation. Furthermore, E4orf4 reduces PARP-1 phosphorylation on serine residues, which likely contributes to PARP-1 inhibition as phosphorylation of this enzyme was reported to enhance its activity. PARP-1 inhibition is important to Ad infection since treatment with a PARP inhibitor enhances replication efficiency. When E4orf4 is expressed alone, it associates with poly(ADP-ribose) (PAR) chains and is recruited to DNA damage sites in a PARP-1-dependent manner. This recruitment is required for inhibition of drug-induced ATR signaling by E4orf4 and for E4orf4-induced cancer cell death. Thus, the results presented here demonstrate a novel mechanism by which E4orf4 targets and inhibits DNA damage signaling through an association with PARP-1 for the benefit of the virus and impacting E4orf4-induced cancer cell death.IMPORTANCE Replication intermediates and ends of viral DNA genomes can be recognized by the cellular DNA damage response (DDR) network as DNA damage whose repair may lead to inhibition of virus replication. Therefore, many viruses evolved mechanisms to inhibit the DDR network. We have previously shown that the adenovirus (Ad) E4orf4 protein inhibits DDR signaling, but the mechanisms were not identified. Here, we describe an association of E4orf4 with the DNA damage sensor poly(ADP-ribose) polymerase 1 (PARP-1). E4orf4 reduces phosphorylation of this enzyme and inhibits its activity. PARP-1 inhibition assists E4orf4 in reducing Ad-induced DDR signaling and improves the efficiency of virus replication. Furthermore, the ability of E4orf4, when expressed alone, to accumulate at DNA damage sites and to kill cancer cells is attenuated by chemical inhibition of PARP-1. Our results indicate that the E4orf4-PARP-1 interaction has an important role in Ad replication and in promotion of E4orf4-induced cancer-selective cell death.
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Affiliation(s)
- Keren Nebenzahl-Sharon
- Department of Molecular Microbiology, the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Rakefet Sharf
- Department of Molecular Microbiology, the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Jana Amer
- Department of Molecular Microbiology, the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | - Hassan Shalata
- Department of Molecular Microbiology, the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
| | | | - Sook-Young Sohn
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Nabieh Ayoub
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Patrick Hearing
- Department of Molecular Genetics and Microbiology, School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Tamar Kleinberger
- Department of Molecular Microbiology, the Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, Israel
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Biphasic Functional Interaction between the Adenovirus E4orf4 Protein and DNA-PK. J Virol 2019; 93:JVI.01365-18. [PMID: 30842317 DOI: 10.1128/jvi.01365-18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 02/22/2019] [Indexed: 02/06/2023] Open
Abstract
The adenovirus (Ad) E4orf4 protein contributes to virus-induced inhibition of the DNA damage response (DDR) by reducing ATM and ATR signaling. Consequently, E4orf4 inhibits DNA repair and sensitizes transformed cells to killing by DNA-damaging drugs. Inhibition of ATM and ATR signaling contributes to the efficiency of virus replication and may provide one explanation for the cancer selectivity of cell death induced by the expression of E4orf4 alone. In this report, we investigate a direct interaction of E4orf4 with the DDR. We show that E4orf4 physically associates with the DNA-dependent protein kinase (DNA-PK), and we demonstrate a biphasic functional interaction between these proteins, wherein DNA-PK is required for ATM and ATR inhibition by E4orf4 earlier during infection but is inhibited by E4orf4 as infection progresses. This biphasic process is accompanied by initial augmentation and a later inhibition of DNA-PK autophosphorylation as well as by colocalization of DNA-PK with early Ad replication centers and distancing of DNA-PK from late replication centers. Moreover, inhibition of DNA-PK improves Ad replication more effectively when a DNA-PK inhibitor is added later rather than earlier during infection. When expressed alone, E4orf4 is recruited to DNA damage sites in a DNA-PK-dependent manner. DNA-PK inhibition reduces the ability of E4orf4 to induce cancer cell death, likely because E4orf4 is prevented from arriving at the damage sites and from inhibiting the DDR. Our results support an important role for the E4orf4-DNA-PK interaction in Ad replication and in facilitation of E4orf4-induced cancer-selective cell death.IMPORTANCE Several DNA viruses evolved mechanisms to inhibit the cellular DNA damage response (DDR), which acts as an antiviral defense system. We present a novel mechanism by which the adenovirus (Ad) E4orf4 protein inhibits the DDR. E4orf4 interacts with the DNA damage sensor DNA-PK in a biphasic manner. Early during infection, E4orf4 requires DNA-PK activity to inhibit various branches of the DDR, whereas it later inhibits DNA-PK itself. Furthermore, although both E4orf4 and DNA-PK are recruited to virus replication centers (RCs), DNA-PK is later distanced from late-phase RCs. Delayed DNA-PK inhibition greatly contributes to Ad replication efficiency. When E4orf4 is expressed alone, it is recruited to DNA damage sites. Inhibition of DNA-PK prevents both recruitment and the previously reported ability of E4orf4 to kill cancer cells. Our results support an important role for the E4orf4-DNA-PK interaction in Ad replication and in facilitation of E4orf4-induced cancer-selective cell death.
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Li D, Tian G, Wang J, Zhao LY, Co O, Underill ZC, Mymryk JS, Claessens F, Dehm SM, Daaka Y, Liao D. Inhibition of androgen receptor transactivation function by adenovirus type 12 E1A undermines prostate cancer cell survival. Prostate 2018; 78:1140-1156. [PMID: 30009471 PMCID: PMC6424568 DOI: 10.1002/pros.23689] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 06/26/2018] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mutations or truncation of the ligand-binding domain (LBD) of androgen receptor (AR) underlie treatment resistance for prostate cancer (PCa). Thus, targeting the AR N-terminal domain (NTD) could overcome such resistance. METHODS Luciferase reporter assays after transient transfection of various DNA constructs were used to assess effects of E1A proteins on AR-mediated transcription. Immunofluorescence microscopy and subcellular fractionation were applied to assess intracellular protein localization. Immunoprecipitation and mammalian two-hybrid assays were used to detect protein-protein interactions. qRT-PCR was employed to determine RNA levels. Western blotting was used to detect protein expression in cells. Effects of adenoviruses on prostate cancer cell survival were evaluated with CellTiter-Glo assays. RESULTS Adenovirus 12 E1A (E1A12) binds specifically to the AR. Interestingly, the full-length E1A12 (266 aa) preferentially binds to full-length AR, while the small E1A12 variant (235 aa) interacts more strongly with AR-V7. E1A12 promotes AR nuclear translocation, likely through mediating intramolecular AR NTD-LBD interactions. In the nucleus, AR and E1A12 co-expression in AR-null PCa cells results in E1A12 redistribution from nuclear foci containing CBX4 (also known as Pc2), suggesting a preferential AR-E1A12 interaction over other E1A12 interactors. E1A12 represses AR-mediated transcription in reporter gene assays and endogenous AR target genes such as ATAD2 and MYC in AR-expressing PCa cells. AR-expressing PCa cells are more sensitive to death induced by a recombinant adenovirus expressing E1A12 (Ad-E1A12) than AR-deficient PCa cells, which could be attributed to the increased viral replication promoted by androgen stimulation. Targeting the AR by E1A12 promotes apoptosis in PCa cells that express the full-length AR or C-terminally truncated AR variants. Importantly, inhibition of mTOR signaling that blocks the expression of anti-apoptotic proteins markedly augments Ad-E1A12-induced apoptosis of AR-expressing cells. Mechanistically, Ad-E1A12 infection triggers apoptotic response while activating the PI3K-AKT-mTOR signaling axis; thus, mTOR inhibition enhances apoptosis in AR-expressing PCa cells infected by Ad-E1A12. CONCLUSION Ad12 E1A inhibits AR-mediated transcription and suppresses PCa cell survival, suggesting that targeting the AR by E1A12 might have therapeutic potential for treating advanced PCa with heightened AR signaling.
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Affiliation(s)
- Dawei Li
- Department of Urology, Qilu Hospital of Shandong University, 107 Wenhuaxi Road, Jinan, 250012, P. R. China
- Department of Anatomy and Cell Biology, UF Health Cancer Center and UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Guimei Tian
- Department of Anatomy and Cell Biology, UF Health Cancer Center and UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Jia Wang
- Department of Anatomy and Cell Biology, UF Health Cancer Center and UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida 32610
- Affiliated Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, P. R. China
| | - Lisa Y. Zhao
- Department of Anatomy and Cell Biology, UF Health Cancer Center and UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida 32610
- Present address: Department of Medicine, University of Florida, Gainesville, FL 32610
| | - Olivia Co
- Department of Anatomy and Cell Biology, UF Health Cancer Center and UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Zoe C. Underill
- Department of Anatomy and Cell Biology, UF Health Cancer Center and UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Joe S. Mymryk
- Department of Microbiology and Immunology, the University of Western Ontario, London Regional Cancer Centre, Ontario, Canada
| | - Frank Claessens
- Laboratory of Molecular Endocrinology, Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49 PO box 901, 3000 Leuven, Belgium
| | - Scott M. Dehm
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota 55455
| | - Yehia Daaka
- Department of Anatomy and Cell Biology, UF Health Cancer Center and UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida 32610
| | - Daiqing Liao
- Department of Anatomy and Cell Biology, UF Health Cancer Center and UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida 32610
- Corresponding author: Department of Anatomy and Cell Biology, University of Florida, 1333 Center Drive, Gainesville, Florida, 32610-0235, , Phone: 352-273-8188, Fax: 352-846-1248
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Wechman SL, Rao XM, Gomez-Gutierrez JG, Zhou HS, McMasters KM. The role of JNK phosphorylation as a molecular target to enhance adenovirus replication, oncolysis and cancer therapeutic efficacy. Cancer Biol Ther 2018; 19:1174-1184. [PMID: 30067431 PMCID: PMC6301809 DOI: 10.1080/15384047.2018.1491503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/31/2018] [Accepted: 06/17/2018] [Indexed: 01/17/2023] Open
Abstract
Oncolytic adenoviruses (Ads) are cancer selective tumoricidal agents; however their mechanism of Ad-mediated cancer cell lysis, or oncolysis, remains undefined. This report focuses upon the autophagy mediator c-JUN n-terminal kinase (JNK) and its effects upon Ad oncolysis and replication. Previously, E1b-deleted Ads have been used to treat several hundred cancer patients with limited clinical efficacy. We hypothesize that by studying the potential interactions between E1b and JNK, mechanisms to improve oncolytic Ad design and cancer therapeutic efficacy may be elucidated. To test this hypothesis, E1b was selectively deleted from the Ad genome. These studies indicated that Ads encoding E1b induced JNK phosphorylation predominately occurred via E1b-19K. The expression of another crucial Ad gene E1a was then overexpressed by the CMV promoter via the replication competent Ad vector Adhz69; these data indicated that E1A also induced JNK phosphorylation. To assess the effects of host cell JNK expression upon Ad oncolysis and replication, siRNA targeting JNK1 and JNK2 (JNK1/2) were utilized. The oncolysis and replication of the E1b-19K wild-type Ads Ad5 and Adhz63 were significantly attenuated following JNK1/2 siRNA transfection. However the oncolytic effects and replication of the E1b-19K deleted Ad Adhz60 were not altered by JNK1/2 siRNA transfection, further implicating the crucial role of E1b-19K for Ad oncolysis and replication via JNK phosphorylation. This study has demonstrated for the first time that JNK is an intriguing molecular marker associated with enhanced Ad virotherapy efficacy, influencing future Ad vector design.
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Affiliation(s)
- Stephen L. Wechman
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
- Department of Human and Molecular Genetics, Virginia Commonwealth University, School of Medicine, Richmond, VA, USA
| | - Xiao-Mei Rao
- Department of Surgery, University of Louisville School of Medicine, Louisville, KY, USA
- James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY, USA
| | - Jorge G. Gomez-Gutierrez
- Department of Surgery, University of Louisville School of Medicine, Louisville, KY, USA
- James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY, USA
| | - Heshan Sam Zhou
- Department of Surgery, University of Louisville School of Medicine, Louisville, KY, USA
- James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY, USA
- Department of Microbiology and Immunology, University of Louisville School of Medicine, Louisville, KY, USA
| | - Kelly M. McMasters
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, KY, USA
- Department of Surgery, University of Louisville School of Medicine, Louisville, KY, USA
- James Graham Brown Cancer Center, University of Louisville School of Medicine, Louisville, KY, USA
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González-Morales A, Zabaleta A, Guruceaga E, Alonso MM, García-Moure M, Fernández-Irigoyen J, Santamaría E. Spatial and temporal proteome dynamics of glioma cells during oncolytic adenovirus Delta-24-RGD infection. Oncotarget 2018; 9:31045-31065. [PMID: 30123426 PMCID: PMC6089549 DOI: 10.18632/oncotarget.25774] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 06/22/2018] [Indexed: 11/25/2022] Open
Abstract
Glioblastoma multiforme (GBM) is the most common and aggressive type of malignant glioma. Oncolytic adenoviruses are being modified to exploit the aberrant expression of proteins in tumor cells to increase the antiglioma efficacy. E1A mutant adenovirus Delta-24-RGD (DNX-2401) has shown a favorable toxicity profile and remarkable efficacy in a first-in-human phase I clinical trial. However, the comprehensive modulation of glioma metabolism in response to Delta-24-RGD infection is poorly understood. Integrating mass spectrometry based-quantitative proteomics, physical and functional interaction data, and biochemical approaches, we conducted a cell-wide study of cytosolic, nuclear, and secreted glioma proteomes throughout the early time course of Delta-24-RGD infection. In addition to the severe proteostasis impairment detected during the first hours post-infection (hpi), Delta-24-RGD induces a transient inhibition of signal transducer and activator of transcription 3 (STAT3), and transcription factor AP-1 (c-JUN) between 3 and 10hpi, increasing the nuclear factor kappa B (NF-κB) activity at 6hpi. Furthermore, Delta-24-RGD specifically modulates the activation dynamics of protein kinase C (PKC), extracellular signal-regulated kinase 1/2 (ERK1/2), and p38 mitogen-activated protein kinase (p38 MAPK) pathways early in infection. At extracellular level, Delta-24-RGD triggers a time -dependent dynamic production of multitasking cytokines, and chemotactic factors, suggesting potential pleiotropic effects on the immune system reactivation. Taken together, these data help us to understand the mechanisms used by Delta-24-RGD to exploit glioma proteome organization. Further mining of this proteomic resource may enable design and engineering complementary adenoviral based-vectors to increase the specificity and potency against glioma.
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Affiliation(s)
- Andrea González-Morales
- Clinical Neuroproteomics Group, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), Irunlarrea, Pamplona, Spain.,IDISNA, Navarra Institute for Health Research, Pamplona, Spain.,Proteored-ISCIII, Proteomics Unit, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), Irunlarrea, Pamplona, Spain
| | - Aintzane Zabaleta
- IDISNA, Navarra Institute for Health Research, Pamplona, Spain.,Oncohematology Area, University Hospital of Navarra, Center for Applied Medical Research, CIBERONC, Pamplona, Spain
| | - Elizabeth Guruceaga
- IDISNA, Navarra Institute for Health Research, Pamplona, Spain.,Bioinformatics Unit, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Marta M Alonso
- IDISNA, Navarra Institute for Health Research, Pamplona, Spain.,Program in Solid Tumors and Biomarkers, Foundation for the Applied Medical Research, Pamplona, Spain.,Department of Pediatrics, University Hospital of Navarra, Pamplona, Spain
| | - Marc García-Moure
- IDISNA, Navarra Institute for Health Research, Pamplona, Spain.,Program in Solid Tumors and Biomarkers, Foundation for the Applied Medical Research, Pamplona, Spain.,Department of Pediatrics, University Hospital of Navarra, Pamplona, Spain
| | - Joaquín Fernández-Irigoyen
- Clinical Neuroproteomics Group, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), Irunlarrea, Pamplona, Spain.,IDISNA, Navarra Institute for Health Research, Pamplona, Spain.,Proteored-ISCIII, Proteomics Unit, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), Irunlarrea, Pamplona, Spain
| | - Enrique Santamaría
- Clinical Neuroproteomics Group, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), Irunlarrea, Pamplona, Spain.,IDISNA, Navarra Institute for Health Research, Pamplona, Spain.,Proteored-ISCIII, Proteomics Unit, Navarrabiomed, Complejo Hospitalario de Navarra (CHN), Universidad Pública de Navarra (UPNA), Irunlarrea, Pamplona, Spain
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Kumar R, Khandelwal N, Thachamvally R, Tripathi BN, Barua S, Kashyap SK, Maherchandani S, Kumar N. Role of MAPK/MNK1 signaling in virus replication. Virus Res 2018; 253:48-61. [PMID: 29864503 PMCID: PMC7114592 DOI: 10.1016/j.virusres.2018.05.028] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 04/16/2018] [Accepted: 05/31/2018] [Indexed: 12/23/2022]
Abstract
Viruses are known to exploit cellular signaling pathways. MAPK is a major cell signaling pathway activated by diverse group of viruses. MNK1 regulates both cap-dependent and IRES-mediated mRNA translation. This review discuss the role of MAPK, particularly the role of MNK1 in virus replication.
Viruses are obligate intracellular parasites; they heavily depend on the host cell machinery to effectively replicate and produce new progeny virus particles. Following viral infection, diverse cell signaling pathways are initiated by the cells, with the major goal of establishing an antiviral state. However, viruses have been shown to exploit cellular signaling pathways for their own effective replication. Genome-wide siRNA screens have also identified numerous host factors that either support (proviral) or inhibit (antiviral) virus replication. Some of the host factors might be dispensable for the host but may be critical for virus replication; therefore such cellular factors may serve as targets for development of antiviral therapeutics. Mitogen activated protein kinase (MAPK) is a major cell signaling pathway that is known to be activated by diverse group of viruses. MAPK interacting kinase 1 (MNK1) has been shown to regulate both cap-dependent and internal ribosomal entry sites (IRES)-mediated mRNA translation. In this review we have discuss the role of MAPK in virus replication, particularly the role of MNK1 in replication and translation of viral genome.
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Affiliation(s)
- Ram Kumar
- Virology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana 125001, India; Department of Veterinary Microbiology and Biotechnology, Rajasthan University of Veterinary and Animal Sciences, Bikaner, Rajasthan 334001, India
| | - Nitin Khandelwal
- Virology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana 125001, India
| | - Riyesh Thachamvally
- Virology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana 125001, India
| | - Bhupendra Nath Tripathi
- Virology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana 125001, India
| | - Sanjay Barua
- Virology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana 125001, India
| | - Sudhir Kumar Kashyap
- Department of Veterinary Microbiology and Biotechnology, Rajasthan University of Veterinary and Animal Sciences, Bikaner, Rajasthan 334001, India
| | - Sunil Maherchandani
- Department of Veterinary Microbiology and Biotechnology, Rajasthan University of Veterinary and Animal Sciences, Bikaner, Rajasthan 334001, India
| | - Naveen Kumar
- Virology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana 125001, India.
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Wang X, Qi X, Yang B, Chen S, Wang J. Autophagy Benefits the Replication of Egg Drop Syndrome Virus in Duck Embryo Fibroblasts. Front Microbiol 2018; 9:1091. [PMID: 29896171 PMCID: PMC5986908 DOI: 10.3389/fmicb.2018.01091] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 05/07/2018] [Indexed: 12/19/2022] Open
Abstract
Egg drop syndrome virus (EDSV) is an economically important pathogen with a broad host range, and it causes disease that leads to markedly decreased egg production. Although EDSV is known to induce apoptosis in duck embryo fibroblasts (DEFs), the interaction between EDSV and its host needs to be further researched. Here, we provide the first evidence that EDSV infection triggers autophagy in DEFs through increases in autophagosome-like double-membrane vesicles, the conversion of LC3-I to LC3-II, and LC3 colocalization with viral hexon proteins. Conversely, P62/SQSTM1 degradation, LC3-II turnover, and colocalization of LAMP and LC3 confirmed that EDSV infection triggers complete autophagy. Furthermore, we demonstrated that inhibition of autophagy by chloroquine (CQ) and 3-methyladenine (3MA) or RNA interference targeting ATG-7 decreased the yield of EDSV progeny. In contrast, induction of autophagy by rapamycin increased the EDSV progeny yield. In addition, we preliminarily demonstrated that the class I phosphoinositide 3-kinase (PI3K)/Akt/mTOR pathway contributes to autophagic induction following EDSV infection. Altogether, these finding lead us to conclude that EDSV infection induces autophagy, which benefits its own replication in host cells. These findings provide novel insights into EDSV-host interactions.
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Affiliation(s)
- Xueping Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Xuefeng Qi
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Bo Yang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Shuying Chen
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
| | - Jingyu Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, China
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22
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Battling for Ribosomes: Translational Control at the Forefront of the Antiviral Response. J Mol Biol 2018; 430:1965-1992. [PMID: 29746850 DOI: 10.1016/j.jmb.2018.04.040] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/24/2018] [Accepted: 04/27/2018] [Indexed: 01/05/2023]
Abstract
In the early stages of infection, gaining control of the cellular protein synthesis machinery including its ribosomes is the ultimate combat objective for a virus. To successfully replicate, viruses unequivocally need to usurp and redeploy this machinery for translation of their own mRNA. In response, the host triggers global shutdown of translation while paradoxically allowing swift synthesis of antiviral proteins as a strategy to limit collateral damage. This fundamental conflict at the level of translational control defines the outcome of infection. As part of this special issue on molecular mechanisms of early virus-host cell interactions, we review the current state of knowledge regarding translational control during viral infection with specific emphasis on protein kinase RNA-activated and mammalian target of rapamycin-mediated mechanisms. We also describe recent technological advances that will allow unprecedented insight into how viruses and host cells battle for ribosomes.
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Mimicry of Cellular A Kinase-Anchoring Proteins Is a Conserved and Critical Function of E1A across Various Human Adenovirus Species. J Virol 2018; 92:JVI.01902-17. [PMID: 29367252 DOI: 10.1128/jvi.01902-17] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 01/18/2018] [Indexed: 12/14/2022] Open
Abstract
The E1A proteins of the various human adenovirus (HAdV) species perform the critical task of converting an infected cell into a setting primed for virus replication. While E1A proteins differ in both sequence and mechanism, the evolutionary pressure on viruses with limited coding capacity ensures that these proteins often have significant overlap in critical functions. HAdV-5 E1A is known to use mimicry to rewire cyclic AMP (cAMP) signaling by decoupling protein kinase A (PKA) from cellular A kinase-anchoring proteins (AKAPs) and utilizing PKA to its own advantage. We show here that E1As from other species of HAdV also possess this viral AKAP (vAKAP) function and examine how they manipulate PKA. E1A from most species of HAdV examined contain a small AKAP-like motif in their N terminus which targets the docking-dimerization domain of PKA as the binding interface for a conserved protein-protein interaction. This motif is also responsible for an E1A-mediated relocalization of PKA regulatory subunits from the cytoplasm into the nucleus, with species-specific E1A proteins having preference for one particular isoform of PKA subunit over another. Importantly, we showed that these newly characterized vAKAPs can integrate into cAMP-responsive transcription as well as contribute to viral genome replication and infectious progeny production for several distinct HAdV species.IMPORTANCE These data enhance the mechanistic knowledge on how HAdV E1A manipulates cellular PKA to benefit infection. The work establishes that mimicry of AKAPs and subversion of PKA-mediated cAMP signaling are conserved features for numerous human adenoviruses. This study also highlights the molecular determinants conferring selective protein-protein interactions between distinct PKA regulatory subunits and the different E1A proteins of these viruses. Additionally, it further emphasizes the utility of using viral proteins like E1A as tools for studying the molecular biology of cellular regulatory pathways.
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24
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Lebaschi A, Nakagawa Y, Wada S, Cong GT, Rodeo SA. Tissue-specific endothelial cells: a promising approach for augmentation of soft tissue repair in orthopedics. Ann N Y Acad Sci 2018; 1410:44-56. [PMID: 29265420 DOI: 10.1111/nyas.13575] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 11/12/2017] [Accepted: 11/13/2017] [Indexed: 12/13/2022]
Abstract
Biologics are playing an increasingly significant role in the practice of modern medicine and surgery in general and orthopedics in particular. Cell-based approaches are among the most important and widely used modalities in orthopedic biologics, with mesenchymal stem cells and other multi/pluripotent cells undergoing evaluation in numerous preclinical and clinical studies. On the other hand, fully differentiated endothelial cells (ECs) have been found to perform critical roles in homeostasis of visceral tissues through production of an adaptive panel of so-called "angiocrine factors." This newly discovered function of ECs renders them excellent candidates for novel approaches in cell-based biologics. Here, we present a review of the role of ECs and angiocrine factors in some visceral tissues, followed by an overview of current cell-based approaches and a discussion of the potential applications of ECs in soft tissue repair.
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Affiliation(s)
- Amir Lebaschi
- Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, New York
| | - Yusuke Nakagawa
- Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, New York
| | - Susumu Wada
- Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, New York
| | - Guang-Ting Cong
- Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, New York
| | - Scott A Rodeo
- Orthopedic Soft Tissue Research Program, Hospital for Special Surgery, New York, New York.,Sports Medicine and Shoulder Service, Hospital for Special Surgery, New York, New York
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25
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Rajala A, Wang Y, Abcouwer SF, Gardner TW, Rajala RV. Developmental and light regulation of tumor suppressor protein PP2A in the retina. Oncotarget 2018; 9:1505-1523. [PMID: 29416710 PMCID: PMC5788578 DOI: 10.18632/oncotarget.23351] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 11/28/2017] [Indexed: 02/07/2023] Open
Abstract
Protein phosphatases are a group of universal enzymes that are responsible for the dephosphorylation of various proteins and enzymes in cells. Cellular signal transduction events are largely governed by the phosphorylation of key proteins. The length of cellular response depends on the activation of protein phosphatase that dephosphorylates the phosphate groups to halt a biological response, and fine-tune the defined cellular outcome. Dysregulation of these phosphatase(s) results in various disease phenotypes. The retina is a post-mitotic tissue, and oncogenic tyrosine and serine/ threonine kinase activities are important for retinal neuron survival. Aberrant activation of protein phosphatase(s) may have a negative effect on retinal neurons. In the current study, we characterized tumor suppressor protein phosphatase 2 (PP2A), a major serine/ threonine kinase with a broad substrate specificity. Our data suggest that PP2A is developmentally regulated in the retina, localized predominantly in the inner retina, and expressed in photoreceptor inner segments. Our findings indicate that PKCα and mTOR may serve as PP2A substrates. We found that light regulates PP2A activity. Our studies also suggest that rhodopsin regulates PP2A and its substrate(s) dephosphorylation. PP2A substrate phosphorylation is increased in mice lacking the A-subunit of PP2A. However, there is no accompanying effect on retina structure and function. Together, our findings suggest that controlling the activity of PP2A in the retina may be neuroprotective.
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Affiliation(s)
- Ammaji Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
- Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Yuhong Wang
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
- Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Steven F. Abcouwer
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA
- W.K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Thomas W. Gardner
- Department of Ophthalmology and Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA
- W.K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Raju V.S. Rajala
- Department of Ophthalmology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
- Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
- Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
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26
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Soprano AS, Smetana JHC, Benedetti CE. Regulation of tRNA biogenesis in plants and its link to plant growth and response to pathogens. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1861:344-353. [PMID: 29222070 DOI: 10.1016/j.bbagrm.2017.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/29/2017] [Accepted: 12/03/2017] [Indexed: 12/23/2022]
Abstract
The field of tRNA biology, encompassing the functional and structural complexity of tRNAs, has fascinated scientists over the years and is continuously growing. Besides their fundamental role in protein translation, new evidence indicates that tRNA-derived molecules also regulate gene expression and protein synthesis in all domains of life. This review highlights some of the recent findings linking tRNA transcription and modification with plant cell growth and response to pathogens. In fact, mutations in proteins directly involved in tRNA synthesis and modification most often lead to pleiotropic effects on plant growth and immunity. As plants need to optimize and balance their energy and nutrient resources towards growth and defense, regulatory pathways that play a central role in integrating tRNA transcription and protein translation with cell growth control and organ development, such as the auxin-TOR signaling pathway, also influence the plant immune response against pathogens. As a consequence, distinct pathogens employ an array of effector molecules including tRNA fragments to target such regulatory pathways to exploit the plant's translational capacity, gain access to nutrients and evade defenses. An example includes the RNA polymerase III repressor MAF1, a conserved component of the TOR signaling pathway that controls ribosome biogenesis and tRNA synthesis required for plant growth and which is targeted by a pathogen effector molecule to promote disease. This article is part of a Special Issue entitled: SI: Regulation of tRNA synthesis and modification in physiological conditions and disease edited by Dr. Boguta Magdalena.
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Affiliation(s)
- Adriana Santos Soprano
- Brazilian Nacional Biosciences Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-100 Campinas, SP, Brazil
| | - Juliana Helena Costa Smetana
- Brazilian Nacional Biosciences Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-100 Campinas, SP, Brazil
| | - Celso Eduardo Benedetti
- Brazilian Nacional Biosciences Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), 13083-100 Campinas, SP, Brazil.
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27
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Chaudhary N, Gonzalez E, Chang SH, Geng F, Rafii S, Altorki NK, McGraw TE. Adenovirus Protein E4-ORF1 Activation of PI3 Kinase Reveals Differential Regulation of Downstream Effector Pathways in Adipocytes. Cell Rep 2017; 17:3305-3318. [PMID: 28009298 DOI: 10.1016/j.celrep.2016.11.082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 10/05/2016] [Accepted: 11/28/2016] [Indexed: 12/13/2022] Open
Abstract
Insulin activation of phosphatidylinositol 3-kinase (PI3K) regulates metabolism, including the translocation of the Glut4 glucose transporter to the plasma membrane and inactivation of the FoxO1 transcription factor. Adenoviral protein E4-ORF1 stimulates cellular glucose metabolism by mimicking growth-factor activation of PI3K. We have used E4-ORF1 as a tool to dissect PI3K-mediated signaling in adipocytes. E4-ORF1 activation of PI3K in adipocytes recapitulates insulin regulation of FoxO1 but not regulation of Glut4. This uncoupling of PI3K effects occurs despite E4-ORF1 activating PI3K and downstream signaling to levels achieved by insulin. Although E4-ORF1 does not fully recapitulate insulin's effects on Glut4, it enhances insulin-stimulated insertion of Glut4-containing vesicles to the plasma membrane independent of Rab10, a key regulator of Glut4 trafficking. E4-ORF1 also stimulates plasma membrane translocation of ubiquitously expressed Glut1 glucose transporter, an effect that is likely essential for E4-ORF1 to promote an anabolic metabolism in a broad range of cell types.
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Affiliation(s)
- Natasha Chaudhary
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Eva Gonzalez
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Sung-Hee Chang
- Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Fuqiang Geng
- Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Shahin Rafii
- Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Nasser K Altorki
- Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, NY 10065, USA; Lung Cancer Program, Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA
| | - Timothy E McGraw
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA; Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, NY 10065, USA; Lung Cancer Program, Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA.
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28
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Tazawa H, Kuroda S, Hasei J, Kagawa S, Fujiwara T. Impact of Autophagy in Oncolytic Adenoviral Therapy for Cancer. Int J Mol Sci 2017; 18:ijms18071479. [PMID: 28698504 PMCID: PMC5535969 DOI: 10.3390/ijms18071479] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 07/07/2017] [Accepted: 07/07/2017] [Indexed: 02/07/2023] Open
Abstract
Oncolytic virotherapy has recently emerged as a promising strategy for inducing tumor-specific cell death. Adenoviruses are widely and frequently used in oncolytic virotherapy. The mechanism of oncolytic adenovirus-mediated tumor suppression involves virus-induced activation of the autophagic machinery in tumor cells. Autophagy is a cytoprotective process that produces energy via lysosomal degradation of intracellular components as a physiologic response to various stresses, including hypoxia, nutrient deprivation, and disruption of growth signaling. However, infection with oncolytic adenoviruses induces autophagy and subsequent death of tumor cells rather than enhancing their survival. In this review, we summarize the beneficial role of autophagy in oncolytic adenoviral therapy, including the roles of infection, replication, and cell lysis. Numerous factors are involved in the promotion and inhibition of oncolytic adenovirus-mediated autophagy. Furthermore, recent evidence has shown that oncolytic adenoviruses induce autophagy-related immunogenic cell death (ICD), which enhances the antitumor immune response by inducing the activation of danger signal molecules and thus represents a novel cancer immunotherapy. Understanding the precise role of oncolytic adenovirus-induced autophagy and ICD could enhance the therapeutic potential of oncolytic adenoviral therapy for treating various cancers.
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Affiliation(s)
- Hiroshi Tazawa
- Center for Innovative Clinical Medicine, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
- Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
| | - Shinji Kuroda
- Center for Innovative Clinical Medicine, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558, Japan.
- Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
| | - Joe Hasei
- Department of Orthopedic Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
| | - Shunsuke Kagawa
- Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
- Minimally Invasive Therapy Center, Okayama University Hospital, Okayama 700-8558, Japan.
| | - Toshiyoshi Fujiwara
- Department of Gastroenterological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
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29
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Illingworth S, Di Y, Bauzon M, Lei J, Duffy MR, Alvis S, Champion B, Lieber A, Hermiston T, Seymour LW, Beadle J, Fisher K. Preclinical Safety Studies of Enadenotucirev, a Chimeric Group B Human-Specific Oncolytic Adenovirus. Mol Ther Oncolytics 2017; 5:62-74. [PMID: 28480328 PMCID: PMC5415321 DOI: 10.1016/j.omto.2017.03.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 03/18/2017] [Indexed: 11/26/2022] Open
Abstract
Enadenotucirev is an oncolytic group B adenovirus identified by a process of bio-selection for the ability to selectively propagate in and rapidly kill carcinoma cells. It is resistant to inactivation by human blood components, potentially enabling intravenous dosing in patients with metastatic cancer. However, there are no known permissive animal models described for group B adenoviruses that could facilitate a conventional approach to preclinical safety studies. In this manuscript, we describe our tailored preclinical strategy designed to evaluate the key biological properties of enadenotucirev. As enadenotucirev does not replicate in animal cells, a panel of primary human cells was used to evaluate enadenotucirev replication selectivity in vitro, demonstrating that virus genome levels were >100-fold lower in normal cells relative to tumor cells. Acute intravenous tolerability in mice was used to assess virus particle-mediated toxicology and effects on innate immunity. These studies showed that particle toxicity could be ameliorated by dose fractionation, using an initial dose of virus to condition the host such that cytokine responses to subsequent doses were significantly attenuated. This, in turn, supported the initiation of a phase I intravenous clinical trial with a starting dose of 1 × 1010 virus particles given on days 1, 3, and 5.
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Affiliation(s)
| | - Ying Di
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - Maxine Bauzon
- Coagulant Therapeutics, 455 Mission Bay Boulevard South, San Francisco, CA 94158, USA
| | - Janet Lei
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | | | - Simon Alvis
- PsiOxus Therapeutics Ltd., Abingdon OX14 4SD, UK
| | | | - André Lieber
- Division of Medical Genetics, University of Washington, Seattle, WA 98195, USA
| | - Terry Hermiston
- Coagulant Therapeutics, 455 Mission Bay Boulevard South, San Francisco, CA 94158, USA
| | - Len W. Seymour
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
| | - John Beadle
- PsiOxus Therapeutics Ltd., Abingdon OX14 4SD, UK
| | - Kerry Fisher
- PsiOxus Therapeutics Ltd., Abingdon OX14 4SD, UK
- Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK
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30
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McMurphy TB, Huang W, Xiao R, Liu X, Dhurandhar NV, Cao L. Hepatic Expression of Adenovirus 36 E4ORF1 Improves Glycemic Control and Promotes Glucose Metabolism Through AKT Activation. Diabetes 2017; 66:358-371. [PMID: 27903748 PMCID: PMC5248996 DOI: 10.2337/db16-0876] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 11/21/2016] [Indexed: 02/07/2023]
Abstract
Considering that impaired proximal insulin signaling is linked with diabetes, approaches that enhance glucose disposal independent of insulin signaling are attractive. In vitro data indicate that the E4ORF1 peptide derived from human adenovirus 36 (Ad36) interacts with cells from adipose tissue, skeletal muscle, and liver to enhance glucose disposal, independent of proximal insulin signaling. Adipocyte-specific expression of Ad36E4ORF1 improves hyperglycemia in mice. To determine the hepatic interaction of Ad36E4ORF1 in enhancing glycemic control, we expressed E4ORF1 of Ad36 or Ad5 or fluorescent tag alone by using recombinant adeno-associated viral vector in the liver of three mouse models. In db/db or diet-induced obesity (DIO) mice, hepatic expression of Ad36E4ORF1 but not Ad5E4ORF1 robustly improved glycemic control. In normoglycemic wild-type mice, hepatic expression of Ad36E4ORF1 lowered nonfasting blood glucose at a high dose of expression. Of note, Ad36E4ORF1 significantly reduced insulin levels in db/db and DIO mice. The improvement in glycemic control was observed without stimulation of the proximal insulin signaling pathway. Collectively, these data indicate that Ad36E4ORF1 is not a typical sensitizer, mimetic, or secretagogue of insulin. Instead, it may have insulin-sparing action, which seems to reduce the need for insulin and, hence, to reduce insulin levels.
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Affiliation(s)
- Travis B McMurphy
- Department of Cancer Biology and Genetics, Ohio State University, Columbus, OH
- The Comprehensive Cancer Center, Ohio State University, Columbus, OH
| | - Wei Huang
- Department of Cancer Biology and Genetics, Ohio State University, Columbus, OH
- The Comprehensive Cancer Center, Ohio State University, Columbus, OH
| | - Run Xiao
- Department of Cancer Biology and Genetics, Ohio State University, Columbus, OH
- The Comprehensive Cancer Center, Ohio State University, Columbus, OH
| | - Xianglan Liu
- Department of Cancer Biology and Genetics, Ohio State University, Columbus, OH
- The Comprehensive Cancer Center, Ohio State University, Columbus, OH
| | | | - Lei Cao
- Department of Cancer Biology and Genetics, Ohio State University, Columbus, OH
- The Comprehensive Cancer Center, Ohio State University, Columbus, OH
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31
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Wang Y, Li D, Luo J, Tian G, Zhao LY, Liao D. Intrinsic cellular signaling mechanisms determine the sensitivity of cancer cells to virus-induced apoptosis. Sci Rep 2016; 6:37213. [PMID: 27849011 PMCID: PMC5111159 DOI: 10.1038/srep37213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 10/26/2016] [Indexed: 12/28/2022] Open
Abstract
Cancer cells of epithelial and mesenchymal phenotypes exhibit different sensitivities to apoptosis stimuli, but the mechanisms underlying this phenomenon remain partly understood. We constructed a novel recombinant adenovirus expressing Ad12 E1A (Ad-E1A12) that can strongly induce apoptosis. Ad-E1A12 infection of epithelial cancer cells displayed dramatic detachment and apoptosis, whereas cancer cells of mesenchymal phenotypes with metastatic propensity were markedly more resistant to this virus. Notably, forced detachment of epithelial cells did not further sensitize them to Ad-E1A12-induced apoptosis, suggesting that cell detachment is a consequence rather than the cause of Ad-E1A12-induced apoptosis. Ad-E1A12 increased phosphorylation of AKT1 and ribosomal protein S6 through independent mechanisms in different cell types. Ad-E1A12–induced AKT1 phosphorylation was PI3K-dependent in epithelial cancer cells, and mTOR-dependent in mesenchymal cancer cells. Epithelial cancer cells upon Ad-E1A12-induced detachment could not sustain AKT activation due to AKT1 degradation, but AKT1 activation was maintained in mesenchymal cancer cells. Expression of epithelial cell-restricted miR-200 family in mesenchymal cells limited mTOR signaling and sensitized them to Ad-E1A12-induced cell killing. Thus, epithelial cancer cells rely on the canonical PI3K-AKT signaling pathway for survival, while mesenchymal cancer cells deploy the PI3K-independent mTORC2-AKT axis in response to strong death stimuli.
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Affiliation(s)
- Yunfei Wang
- Department of Anatomy and Cell Biology, UF Health Cancer Center, UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida, USA.,Shaanxi Key Laboratory of Agriculture Molecular Biology, Department of Biochemistry and Molecular Biology, College of Life Science, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Dawei Li
- Department of Anatomy and Cell Biology, UF Health Cancer Center, UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida, USA.,Department of Urology, Qilu Hospital, Shandong University, Jinan, Shandong, China
| | - Jian Luo
- Department of Anatomy and Cell Biology, UF Health Cancer Center, UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Guimei Tian
- Department of Anatomy and Cell Biology, UF Health Cancer Center, UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Lisa Y Zhao
- Department of Anatomy and Cell Biology, UF Health Cancer Center, UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Daiqing Liao
- Department of Anatomy and Cell Biology, UF Health Cancer Center, UF Genetics Institute, University of Florida College of Medicine, Gainesville, Florida, USA
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Su BH, Shieh GS, Tseng YL, Shiau AL, Wu CL. Etoposide enhances antitumor efficacy of MDR1-driven oncolytic adenovirus through autoupregulation of the MDR1 promoter activity. Oncotarget 2016; 6:38308-26. [PMID: 26515462 PMCID: PMC4742001 DOI: 10.18632/oncotarget.5702] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 10/06/2015] [Indexed: 12/11/2022] Open
Abstract
Conditionally replicating adenoviruses (CRAds), or oncolytic adenoviruses, such as E1B55K-deleted adenovirus, are attractive anticancer agents. However, the therapeutic efficacy of E1B55K-deleted adenovirus for refractory solid tumors has been limited. Environmental stress conditions may induce nuclear accumulation of YB-1, which occurs in multidrug-resistant and adenovirus-infected cancer cells. Overexpression and nuclear localization of YB-1 are associated with poor prognosis and tumor recurrence in various cancers. Nuclear YB-1 transactivates the multidrug resistance 1 (MDR1) genes through the Y-box. Here, we developed a novel E1B55K-deleted adenovirus driven by the MDR1 promoter, designed Ad5GS3. We tested the feasibility of using YB-1 to transcriptionally regulate Ad5GS3 replication in cancer cells and thereby to enhance antitumor efficacy. We evaluated synergistic antitumor effects of oncolytic virotherapy in combination with chemotherapy. Our results show that adenovirus E1A induced E2F-1 activity to augment YB-1 expression, which shut down host protein synthesis in cancer cells during adenovirus replication. In cancer cells infected with Ad5WS1, an E1B55K-deleted adenovirus driven by the E1 promoter, E1A enhanced YB-1 expression, and then further phosphorylated Akt, which, in turn, triggered nuclear translocation of YB-1. Ad5GS3 in combination with chemotherapeutic agents facilitated nuclear localization of YB-1 and, in turn, upregulated the MDR1 promoter activity and enhanced Ad5GS3 replication in cancer cells. Thus, E1A, YB-1, and the MDR1 promoter form a positive feedback loop to promote Ad5GS3 replication in cancer cells, and this regulation can be further augmented when chemotherapeutic agents are added. In the in vivo study, Ad5GS3 in combination with etoposide synergistically suppressed tumor growth and prolonged survival in NOD/SCID mice bearing human lung tumor xenografts. More importantly, Ad5GS3 exerted potent oncolytic activity against clinical advanced lung adenocarcinoma, which was associated with elevated levels of nuclear YB-1 and cytoplasmic MDR1 expression in the advanced tumors. Therefore, Ad5GS3 may have therapeutic potential for cancer treatment, especially in combination with chemotherapy. Because YB-1 is expressed in a broad spectrum of cancers, this oncolytic adenovirus may be broadly applicable.
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Affiliation(s)
- Bing-Hua Su
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Gia-Shing Shieh
- Department of Urology, Tainan Hospital, Ministry of Health and Welfare, Executive Yuan, Tainan, Taiwan
| | - Yau-Lin Tseng
- Division of Thoracic Surgery, Department of Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Ai-Li Shiau
- Department of Microbiology and Immunology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chao-Liang Wu
- Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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Carinhas N, Koshkin A, Pais DAM, Alves PM, Teixeira AP. 13 C-metabolic flux analysis of human adenovirus infection: Implications for viral vector production. Biotechnol Bioeng 2016; 114:195-207. [PMID: 27477740 DOI: 10.1002/bit.26063] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 07/24/2016] [Accepted: 07/26/2016] [Indexed: 01/08/2023]
Abstract
Adenoviruses are human pathogens increasingly used as gene therapy and vaccination vectors. However, their impact on cell metabolism is poorly characterized. We performed carbon labeling experiments with [1,2-13 C]glucose or [U-13 C]glutamine to evaluate metabolic alterations in the amniocyte-derived, E1-transformed 1G3 cell line during production of a human adenovirus type 5 vector (AdV5). Nonstationary 13 C-metabolic flux analysis revealed increased fluxes of glycolysis (17%) and markedly PPP (over fourfold) and cytosolic AcCoA formation (nearly twofold) following infection of growing cells. Interestingly, infection of growth-arrested cells increased overall carbon flow even more, including glutamine anaplerosis and TCA cycle activity (both over 1.5-fold), but was unable to stimulate the PPP and was associated with a steep drop in AdV5 replication (almost 80%). Our results underscore the importance of nucleic and fatty acid biosynthesis for adenovirus replication. Overall, we portray a metabolic blueprint of human adenovirus infection, highlighting similarities with other viruses and cancer, and suggest strategies to improve AdV5 production. Biotechnol. Bioeng. 2017;114: 195-207. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Nuno Carinhas
- iBET, Instituto de Biologia Experimental e Tecnológica, Avenida da República, Oeiras, 2781-157, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Oeiras, 2780-157, Portugal
| | - Alexey Koshkin
- iBET, Instituto de Biologia Experimental e Tecnológica, Avenida da República, Oeiras, 2781-157, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Oeiras, 2780-157, Portugal
| | - Daniel A M Pais
- iBET, Instituto de Biologia Experimental e Tecnológica, Avenida da República, Oeiras, 2781-157, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Oeiras, 2780-157, Portugal
| | - Paula M Alves
- iBET, Instituto de Biologia Experimental e Tecnológica, Avenida da República, Oeiras, 2781-157, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Oeiras, 2780-157, Portugal
| | - Ana P Teixeira
- iBET, Instituto de Biologia Experimental e Tecnológica, Avenida da República, Oeiras, 2781-157, Portugal.,Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Oeiras, 2780-157, Portugal
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Liem J, Liu J. Stress Beyond Translation: Poxviruses and More. Viruses 2016; 8:v8060169. [PMID: 27314378 PMCID: PMC4926189 DOI: 10.3390/v8060169] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 05/24/2016] [Accepted: 06/08/2016] [Indexed: 02/06/2023] Open
Abstract
Poxviruses are large double-stranded DNA viruses that form viral factories in the cytoplasm of host cells. These viruses encode their own transcription machinery, but rely on host translation for protein synthesis. Thus, poxviruses have to cope with and, in most cases, reprogram host translation regulation. Granule structures, called antiviral granules (AVGs), have been observed surrounding poxvirus viral factories. AVG formation is associated with abortive poxvirus infection, and AVGs contain proteins that are typically found in stress granules (SGs). With certain mutant poxviruses lack of immunoregulatory factor(s), we can specifically examine the mechanisms that drive the formation of these structures. In fact, cytoplasmic macromolecular complexes form during many viral infections and contain sensing molecules that can help reprogram transcription. More importantly, the similarity between AVGs and cytoplasmic structures formed during RNA and DNA sensing events prompts us to reconsider the cause and consequence of these AVGs. In this review, we first summarize recent findings regarding how poxvirus manipulates host translation. Next, we compare and contrast SGs and AVGs. Finally, we review recent findings regarding RNA- and especially DNA-sensing bodies observed during viral infection.
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Affiliation(s)
- Jason Liem
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
| | - Jia Liu
- Department of Microbiology and Immunology, Center for Microbial Pathogenesis and Host Inflammatory Responses, University of Arkansas for Medical Sciences, Little Rock, Arkansas.
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Le Sage V, Cinti A, Amorim R, Mouland AJ. Adapting the Stress Response: Viral Subversion of the mTOR Signaling Pathway. Viruses 2016; 8:v8060152. [PMID: 27231932 PMCID: PMC4926172 DOI: 10.3390/v8060152] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 02/06/2023] Open
Abstract
The mammalian target of rapamycin (mTOR) is a central regulator of gene expression, translation and various metabolic processes. Multiple extracellular (growth factors) and intracellular (energy status) molecular signals as well as a variety of stressors are integrated into the mTOR pathway. Viral infection is a significant stress that can activate, reduce or even suppress the mTOR signaling pathway. Consequently, viruses have evolved a plethora of different mechanisms to attack and co-opt the mTOR pathway in order to make the host cell a hospitable environment for replication. A more comprehensive knowledge of different viral interactions may provide fruitful targets for new antiviral drugs.
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Affiliation(s)
- Valerie Le Sage
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
| | - Alessandro Cinti
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
| | - Raquel Amorim
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
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Keating R, McGargill MA. mTOR Regulation of Lymphoid Cells in Immunity to Pathogens. Front Immunol 2016; 7:180. [PMID: 27242787 PMCID: PMC4862984 DOI: 10.3389/fimmu.2016.00180] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 04/25/2016] [Indexed: 12/15/2022] Open
Abstract
Immunity to pathogens exists as a fine balance between promoting activation and expansion of effector cells, while simultaneously limiting normal and aberrant responses. These seemingly opposing functions are kept in check by immune regulators. The mechanistic target of rapamycin (mTOR) is a serine/threonine kinase that senses nutrient availability and, in turn, regulates cell metabolism, growth, and survival accordingly. mTOR plays a pivotal role in facilitating immune defense against invading pathogens by regulating the differentiation, activation, and effector functions of lymphoid cells. Here, we focus on the emerging and sometimes contradictory roles of mTOR in orchestrating lymphoid cell-mediated host immune responses to pathogens. A thorough understanding of how mTOR impacts lymphoid cells in pathogen defense will provide the necessary base for developing therapeutic interventions for infectious diseases.
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Affiliation(s)
- Rachael Keating
- Department of Immunology, St. Jude Children's Research Hospital , Memphis, TN , USA
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The Adenovirus E4orf4 Protein Provides a Novel Mechanism for Inhibition of the DNA Damage Response. PLoS Pathog 2016; 12:e1005420. [PMID: 26867009 PMCID: PMC4750969 DOI: 10.1371/journal.ppat.1005420] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 01/06/2016] [Indexed: 12/20/2022] Open
Abstract
The DNA damage response (DDR) is a conglomerate of pathways designed to detect DNA damage and signal its presence to cell cycle checkpoints and to the repair machinery, allowing the cell to pause and mend the damage, or if the damage is too severe, to trigger apoptosis or senescence. Various DDR branches are regulated by kinases of the phosphatidylinositol 3-kinase-like protein kinase family, including ataxia-telangiectasia mutated (ATM) and ATM- and Rad3-related (ATR). Replication intermediates and linear double-stranded genomes of DNA viruses are perceived by the cell as DNA damage and activate the DDR. If allowed to operate, the DDR will stimulate ligation of viral genomes and will inhibit virus replication. To prevent this outcome, many DNA viruses evolved ways to limit the DDR. As part of its attack on the DDR, adenovirus utilizes various viral proteins to cause degradation of DDR proteins and to sequester the MRN damage sensor outside virus replication centers. Here we show that adenovirus evolved yet another novel mechanism to inhibit the DDR. The E4orf4 protein, together with its cellular partner PP2A, reduces phosphorylation of ATM and ATR substrates in virus-infected cells and in cells treated with DNA damaging drugs, and causes accumulation of damaged DNA in the drug-treated cells. ATM and ATR are not mutually required for inhibition of their signaling pathways by E4orf4. ATM and ATR deficiency as well as E4orf4 expression enhance infection efficiency. Furthermore, E4orf4, previously reported to induce cancer-specific cell death when expressed alone, sensitizes cells to killing by sub-lethal concentrations of DNA damaging drugs, likely because it inhibits DNA damage repair. These findings provide one explanation for the cancer-specificity of E4orf4-induced cell death as many cancers have DDR deficiencies leading to increased reliance on the remaining intact DDR pathways and to enhanced susceptibility to DDR inhibitors such as E4orf4. Thus DDR inhibition by E4orf4 contributes both to the efficiency of adenovirus replication and to the ability of E4orf4 to kill cancer cells.
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38
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Lévy P, Bartosch B. Metabolic reprogramming: a hallmark of viral oncogenesis. Oncogene 2015; 35:4155-64. [DOI: 10.1038/onc.2015.479] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 11/11/2015] [Accepted: 11/14/2015] [Indexed: 02/07/2023]
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Ouibrahim L, Rubio AG, Moretti A, Montané MH, Menand B, Meyer C, Robaglia C, Caranta C. Potyviruses differ in their requirement for TOR signalling. J Gen Virol 2015; 96:2898-2903. [DOI: 10.1099/vir.0.000186] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- Laurence Ouibrahim
- CNRS, UMR 7265 Biologie Végétale & Microbiologie Environnementales, Marseille F-13009, France
- CEA, IBEB, Marseille F-13009, France
- Genetics and Breeding of Fruits and Vegetables, INRA Avignon, UR1052, CS 60094, Montfavet 84143, France
- Aix-Marseille Université, Laboratoire de Génétique et Biophysique des Plantes, Marseille F-13009, France
| | - Ana Giner Rubio
- Genetics and Breeding of Fruits and Vegetables, INRA Avignon, UR1052, CS 60094, Montfavet 84143, France
| | - André Moretti
- Genetics and Breeding of Fruits and Vegetables, INRA Avignon, UR1052, CS 60094, Montfavet 84143, France
| | - Marie-Hélène Montané
- Aix-Marseille Université, Laboratoire de Génétique et Biophysique des Plantes, Marseille F-13009, France
- CNRS, UMR 7265 Biologie Végétale & Microbiologie Environnementales, Marseille F-13009, France
- CEA, IBEB, Marseille F-13009, France
| | - Benoît Menand
- Aix-Marseille Université, Laboratoire de Génétique et Biophysique des Plantes, Marseille F-13009, France
- CNRS, UMR 7265 Biologie Végétale & Microbiologie Environnementales, Marseille F-13009, France
- CEA, IBEB, Marseille F-13009, France
| | - Christian Meyer
- Institut Jean-Pierre Bourgin, Unité Mixte de Recherche 1318, Institut National de la Recherche Agronomique AgroParisTech, Versailles cedex 78026, France
| | - Christophe Robaglia
- CEA, IBEB, Marseille F-13009, France
- Aix-Marseille Université, Laboratoire de Génétique et Biophysique des Plantes, Marseille F-13009, France
- CNRS, UMR 7265 Biologie Végétale & Microbiologie Environnementales, Marseille F-13009, France
| | - Carole Caranta
- Genetics and Breeding of Fruits and Vegetables, INRA Avignon, UR1052, CS 60094, Montfavet 84143, France
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Adenovirus E4-ORF1 Dysregulates Epidermal Growth Factor and Insulin/Insulin-Like Growth Factor Receptors To Mediate Constitutive Myc Expression. J Virol 2015; 89:10774-85. [PMID: 26269183 DOI: 10.1128/jvi.01463-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/05/2015] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED The E4-ORF1 protein encoded by human adenovirus stimulates viral replication in human epithelial cells by binding and activating cellular phosphatidylinositol 3-kinase (PI3K) at the plasma membrane and cellular Myc in the nucleus. In this study, we showed that E4-ORF1 hijacks the tyrosine kinase activities of cellular epidermal growth factor receptor (EGFR) and insulin receptor (InsR)/insulin-like growth factor receptor 1 (IGF1R), as well as the lipid kinase activity of PI3K, to mediate constitutive Myc protein expression. We additionally demonstrated that EGFR contributes to constitutive Myc expression through the capacity of E4-ORF1 to induce ligand-independent EGFR activation and stimulation of the Ras/Mek/Erk pathway, the latter activity of which was conserved by human adenoviruses. Results further suggested that EGFR normally forms a complex with the cellular PDZ protein Discs Large 1 (Dlg1), a component of the Dlg1:E4-ORF1:PI3K ternary complex that mediates E4-ORF1-induced PI3K activation, and that E4-ORF1 binds the Dlg1:EGFR complex and promotes the association of EGFR with InsR and IGF1R. In addition to its role in constitutive Myc expression, InsR/IGF1R also negatively regulates EGFR autophosphorylation and EGFR-mediated Ras/Mek/Erk signaling, and data suggested that E4-ORF1 binding to Dlg1 antagonizes these activities. Collectively, our findings suggest that in human epithelial cells, E4-ORF1 targets EGFR, InsR/IGF1R, and PI3K at the plasma membrane to activate cytosolic signaling pathways that sustain Myc protein levels in the nucleus. We postulate that E4-ORF1-induced constitutive Myc expression functions to ensure the formation of nuclear E4-ORF1:Myc complexes, which have been shown to activate Myc and to enhance adenovirus replication. IMPORTANCE While human adenoviruses primarily produce self-limited acute infections in humans, these agents are associated with life-threatening diseases in immunocompromised patients and in otherwise healthy individuals infected with certain virulent serotypes. The adenovirus E4-ORF1 protein enhances viral replication by activating the cellular lipid kinase PI3K and the cellular transcription factor Myc. Here we report that E4-ORF1 usurps the functions of the cellular tyrosine kinase receptors EGFR and InsR /: IGF1R, as well as PI3K, to sustain Myc protein expression in cells. Furthermore, sustained Myc expression depended on E4-ORF1-induced ligand-independent EGFR activation that stimulated Ras/Mek/Erk signaling, a function found to be conserved by human adenoviruses. Given the established roles of PI3K, the Ras/Mek/Erk pathway, and Myc in the adenovirus life cycle, our findings may aid in the development of safer, more effective therapeutic strategies to treat severe adenovirus infections as well as improved adenovirus vectors for use in vaccination and gene and cancer therapy.
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The Human Adenovirus Type 5 E4orf4 Protein Targets Two Phosphatase Regulators of the Hippo Signaling Pathway. J Virol 2015; 89:8855-70. [PMID: 26085163 DOI: 10.1128/jvi.03710-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 06/05/2015] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED When expressed alone at high levels, the human adenovirus E4orf4 protein exhibits tumor cell-specific p53-independent toxicity. A major E4orf4 target is the B55 class of PP2A regulatory subunits, and we have shown recently that binding of E4orf4 inhibits PP2A(B55) phosphatase activity in a dose-dependent fashion by preventing access of substrates (M. Z. Mui et al., PLoS Pathog 9:e1003742, 2013, http://dx.doi.org/10.1371/journal.ppat.1003742). While interaction with B55 subunits is essential for toxicity, E4orf4 mutants exist that, despite binding B55 at high levels, are defective in cell killing, suggesting that other essential targets exist. In an attempt to identify additional targets, we undertook a proteomics approach to characterize E4orf4-interacting proteins. Our findings indicated that, in addition to PP2A(B55) subunits, ASPP-PP1 complex subunits were found among the major E4orf4-binding species. Both the PP2A and ASPP-PP1 phosphatases are known to positively regulate effectors of the Hippo signaling pathway, which controls the expression of cell growth/survival genes by dephosphorylating the YAP transcriptional coactivator. We find here that expression of E4orf4 results in hyperphosphorylation of YAP, suggesting that Hippo signaling is affected by E4orf4 interactions with PP2A(B55) and/or ASPP-PP1 phosphatases. Furthermore, knockdown of YAP1 expression was seen to enhance E4orf4 killing, again consistent with a link between E4orf4 toxicity and inhibition of the Hippo pathway. This effect may in fact contribute to the cancer cell specificity of E4orf4 toxicity, as many human cancer cells rely heavily on the Hippo pathway for their enhanced proliferation. IMPORTANCE The human adenovirus E4orf4 protein has been known for some time to induce tumor cell-specific death when expressed at high levels; thus, knowledge of its mode of action could be of importance for development of new cancer therapies. Although the B55 form of the phosphatase PP2A has long been known as an essential E4orf4 target, genetic analyses indicated that others must exist. To identify additional E4orf4 targets, we performed, for the first time, a large-scale affinity purification/mass spectrometry analysis of E4orf4 binding partners. Several additional candidates were detected, including key regulators of the Hippo signaling pathway, which enhances cell viability in many cancers, and results of preliminary studies suggested a link between inhibition of Hippo signaling and E4orf4 toxicity.
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Tuberous Sclerosis Complex Protein 2-Independent Activation of mTORC1 by Human Cytomegalovirus pUL38. J Virol 2015; 89:7625-35. [PMID: 25972538 DOI: 10.1128/jvi.01027-15] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 05/05/2015] [Indexed: 12/24/2022] Open
Abstract
UNLABELLED The mammalian target of rapamycin complex 1 (mTORC1) controls cell growth and anabolic metabolism and is a critical host factor activated by human cytomegalovirus (HCMV) for successful infection. The multifunctional HCMV protein pUL38 previously has been reported to activate mTORC1 by binding to and antagonizing tuberous sclerosis complex protein 2 (TSC2) (J. N. Moorman et al., Cell Host Microbe 3:253-262, 2008, http://dx.doi.org/10.1016/j.chom.2008.03.002). pUL38 also plays a role in blocking endoplasmic reticulum stress-induced cell death during HCMV infection. In this study, we showed that a mutant pUL38 lacking the N-terminal 24 amino acids (pHA-UL3825-331) was fully functional in suppressing cell death during infection. Interestingly, pHA-UL3825-331 lost the ability to interact with TSC2 but retained the ability to activate mTORC1, although to a lesser extent than full-length pHA-UL38. Recombinant virus expressing pHA-UL3825-331 replicated with ∼10-fold less efficiency than the wild-type virus at a low multiplicity of infection (MOI), but it grew similarly well at a high MOI, suggesting an MOI-dependent importance of pUL38-TSC2 interaction in supporting virus propagation. Site-directed mutational analysis identified a TQ motif at amino acid residues 23 and 24 as critical for pUL38 interaction with TSC2. Importantly, when expressed in isolation, the TQ/AA substitution mutant pHA-UL38 TQ/AA was capable of activating mTORC1 just like pHA-UL3825-331. We also created TSC2-null U373-MG cell lines by CRISPR genome editing and showed that pUL38 was capable of further increasing mTORC1 activity in TSC2-null cells. Therefore, this study identified the residues important for pUL38-TSC2 interaction and demonstrated that pUL38 can activate mTORC1 in both TSC2-dependent and -independent manners. IMPORTANCE HCMV, like other viruses, depends exclusively on its host cell to propagate. Therefore, it has developed methods to protect against host stress responses and to usurp cellular processes to complete its life cycle. mTORC1 is believed to be important for virus replication, and HCMV maintains high mTORC1 activity despite the stressful cellular environment associated with infection. mTORC1 inhibitors suppressed HCMV replication in vitro and reduced the incidence of HCMV reactivation in transplant recipients. We demonstrated that mTORC1 was activated by HCMV protein pUL38 in both TSC2-dependent and TSC2-independent manners. The pUL38-independent mode of mTORC1 activation also has been reported. These novel findings suggest the evolution of sophisticated approaches whereby HCMV activates mTORC1, indicating its importance in the biology and pathogenesis of HCMV.
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Kleinberger T. Mechanisms of cancer cell killing by the adenovirus E4orf4 protein. Viruses 2015; 7:2334-57. [PMID: 25961489 PMCID: PMC4452909 DOI: 10.3390/v7052334] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 04/23/2015] [Accepted: 04/30/2015] [Indexed: 12/24/2022] Open
Abstract
During adenovirus (Ad) replication the Ad E4orf4 protein regulates progression from the early to the late phase of infection. However, when E4orf4 is expressed alone outside the context of the virus it induces a non-canonical mode of programmed cell death, which feeds into known cell death pathways such as apoptosis or necrosis, depending on the cell line tested. E4orf4-induced cell death has many interesting and unique features including a higher susceptibility of cancer cells to E4orf4-induced cell killing compared with normal cells, caspase-independence, a high degree of evolutionary conservation of the signaling pathways, a link to perturbations of the cell cycle, and involvement of two distinct cell death programs, in the nucleus and in the cytoplasm. Several E4orf4-interacting proteins including its major partners, protein phosphatase 2A (PP2A) and Src family kinases, contribute to induction of cell death. The various features of E4orf4-induced cell killing as well as studies to decipher the underlying mechanisms are described here. Many explanations for the cancer specificity of E4orf4-induced cell death have been proposed, but a full understanding of the reasons for the different susceptibility of cancer and normal cells to killing by E4orf4 will require a more detailed analysis of the complex E4orf4 signaling network. An improved understanding of the mechanisms involved in this unique mode of programmed cell death may aid in design of novel E4orf4-based cancer therapeutics.
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Affiliation(s)
- Tamar Kleinberger
- Department of Microbiology, Faculty of Medicine, Technion-Israel Institute of Technology, 1 Efron St., Bat Galim, Haifa 31096, Israel.
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Lezhnin YN, Kravchenko YE, Frolova EI, Chumakov PM, Chumakov SP. Oncotoxic proteins in cancer therapy: Mechanisms of action. Mol Biol 2015. [DOI: 10.1134/s0026893315020077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Analysis by live imaging of effects of the adenovirus E4orf4 protein on passage through mitosis of H1299 tumor cells. J Virol 2015; 89:4685-9. [PMID: 25653433 DOI: 10.1128/jvi.03437-14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The adenovirus E4orf4 protein expressed at high levels kills cancer cells but not normal human primary cells. Previous studies suggested that disruption of processes that regulate mitosis may underlie E4orf4 toxicity. Here we have used live imaging to show that E4orf4 induces a slowed defective transit through mitosis, exhibiting a delay or often failure in cytokinesis that may account for an accumulation of G1 tetraploids in the population of dying E4orf4-expressing cells.
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Hijacking Dlg1 for oncogenic phosphatidylinositol 3-kinase activation in human epithelial cells is a conserved mechanism of human adenovirus E4-ORF1 proteins. J Virol 2014; 88:14268-77. [PMID: 25253337 DOI: 10.1128/jvi.02324-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED The E4-ORF1 gene of human adenoviruses encodes a 14-kDa protein that promotes viral replication as well as cellular metabolic reprogramming, survival, and transformation by constitutively activating cellular phosphatidylinositol 3-kinase (PI3K). We recently reported that the E4-ORF1 protein from subgroup D human adenovirus type 9 upregulates and oncogenically activates PI3K by a novel mechanism involving separate interactions of E4-ORF1 with cellular discs large 1 (Dlg1) and PI3K to form a ternary complex that translocates to the plasma membrane (K. Kong, M. Kumar, M. Taruishi, and R. T. Javier, PLoS Pathog. 10:e1004102, 2014, doi:10.1371/journal.ppat.1004102). The current study was carried out to investigate whether other human adenovirus E4-ORF1 proteins share this mechanism of action. The results showed that in human MCF10A epithelial cells, stable expression of E4-ORF1 proteins encoded by representative human adenovirus serotypes from subgroups A to D induce ternary complex formation, Dlg1-dependent PI3K activation, PI3K protein elevation, Dlg1 and PI3K membrane recruitment, and PI3K-dependent cellular transformation. The first three of these E4-ORF1 activities were also observed in MCF10A cells infected with each wild-type human adenovirus from subgroups A to D. Our findings indicate that most, if not all, human adenovirus E4-ORF1 proteins share a conserved molecular mechanism of PI3K activation, which confers a common capacity to promote oncogenic transformation in human epithelial cells. IMPORTANCE PI3K activation by the adenovirus E4-ORF1 protein mediates oncogenic cellular transformation by human adenovirus type 9, augments viral protein expression and replication by human adenovirus type 5, and dysregulates cellular glucose and lipid metabolism by human adenovirus type 36. For the first time, we report that E4-ORF1 proteins from human adenoviruses in subgroups A to D evolved a conserved molecular mechanism to mediate constitutive PI3K activation that can provoke oncogenic transformation in human epithelial cells. The results raise potential safety concerns about the use of vectors encoding the E4-ORF1 gene in human gene therapy and vaccination. Our findings further suggest that the conserved mechanism revealed here may be targeted for development of therapeutic drugs to treat and prevent adenovirus-associated human diseases.
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Adamson AL, Le BT, Siedenburg BD. Inhibition of mTORC1 inhibits lytic replication of Epstein-Barr virus in a cell-type specific manner. Virol J 2014; 11:110. [PMID: 24917448 PMCID: PMC4059732 DOI: 10.1186/1743-422x-11-110] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 06/05/2014] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Epstein-Barr virus is a human herpesvirus that infects a majority of the human population. Primary infection of Epstein-Barr virus (EBV) causes the syndrome infectious mononucleosis. This virus is also associated with several cancers, including Burkitt's lymphoma, post-transplant lymphoproliferative disorder and nasopharyngeal carcinoma. As all herpesvirus family members, EBV initially replicates lytically to produce abundant virus particles, then enters a latent state to remain within the host indefinitely. METHODS Through a genetic screen in Drosophila, we determined that reduction of Drosophila Tor activity altered EBV immediate-early protein function. To further investigate this finding, we inhibited mTOR in EBV-positive cells and investigated subsequent changes to lytic replication via Western blotting, flow cytometry, and quantitative PCR. The student T-test was used to evaluate significance. RESULTS mTOR, the human homolog of Drosophila Tor, is an important protein at the center of a major signaling pathway that controls many aspects of cell biology. As the EBV immediate-early genes are responsible for EBV lytic replication, we examined the effect of inhibition of mTORC1 on EBV lytic replication in human EBV-positive cell lines. We determined that treatment of cells with rapamycin, which is an inhibitor of mTORC1 activity, led to a reduction in the ability of B cell lines to undergo lytic replication. In contrast, EBV-positive epithelial cell lines underwent higher levels of lytic replication when treated with rapamycin. CONCLUSIONS Overall, the responses of EBV-positive cell lines vary when treated with mTOR inhibitors, and this may be important when considering such inhibitors as anti-cancer therapeutic agents.
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Affiliation(s)
- Amy L Adamson
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, USA.
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The human adenovirus E4-ORF1 protein subverts discs large 1 to mediate membrane recruitment and dysregulation of phosphatidylinositol 3-kinase. PLoS Pathog 2014; 10:e1004102. [PMID: 24788832 PMCID: PMC4006922 DOI: 10.1371/journal.ppat.1004102] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 03/18/2014] [Indexed: 12/19/2022] Open
Abstract
Adenoviruses infect epithelial cells lining mucous membranes to cause acute diseases in people. They are also utilized as vectors for vaccination and for gene and cancer therapy, as well as tools to discover mechanisms of cancer due to their tumorigenic potential in experimental animals. The adenovirus E4-ORF1 gene encodes an oncoprotein that promotes viral replication, cell survival, and transformation by activating phosphatidylinositol 3-kinase (PI3K). While the mechanism of activation is not understood, this function depends on a complex formed between E4-ORF1 and the membrane-associated cellular PDZ protein Discs Large 1 (Dlg1), a common viral target having both tumor suppressor and oncogenic functions. Here, we report that in human epithelial cells, E4-ORF1 interacts with the regulatory and catalytic subunits of PI3K and elevates their levels. Like PI3K activation, PI3K protein elevation by E4-ORF1 requires Dlg1. We further show that Dlg1, E4-ORF1, and PI3K form a ternary complex at the plasma membrane. At this site, Dlg1 also co-localizes with the activated PI3K effector protein Akt, indicating that the ternary complex mediates PI3K signaling. Signifying the functional importance of the ternary complex, the capacity of E4-ORF1 to induce soft agar growth and focus formation in cells is ablated either by a mutation that prevents E4-ORF1 binding to Dlg1 or by a PI3K inhibitor drug. These results demonstrate that E4-ORF1 interacts with Dlg1 and PI3K to assemble a ternary complex where E4-ORF1 hijacks the Dlg1 oncogenic function to relocate cytoplasmic PI3K to the membrane for constitutive activation. This novel mechanism of Dlg1 subversion by adenovirus to dysregulate PI3K could be used by other pathogenic viruses, such as human papillomavirus, human T-cell leukemia virus type 1, and influenza A virus, which also target Dlg1 and activate PI3K in cells. Adenoviruses cause acute illnesses in people, and are additionally utilized both as vehicles to cure genetic diseases, fight cancer, and deliver vaccines, and as tools to discover how cancers develop due to a capacity to generate tumors in experimental animals. The adenovirus E4-ORF1 protein reprograms cell metabolism to enhance virus production in infected cells and promotes cell survival and tumors by activating the important cellular protein phosphatidylinositol 3-kinase (PI3K). How E4-ORF1 activates PI3K is not known, though this function depends on E4-ORF1 binding to the membrane-associated cellular protein Discs Large 1 (Dlg1), which many different viruses evolved to target. In this study, we identify PI3K as a new direct target of E4-ORF1. Results further show that E4-ORF1 binds to PI3K in the cytoplasm and delivers it to Dlg1 at the membrane where the three proteins form a complex that activates PI3K and induces oncogenic growth in cells. This novel molecular mechanism in which adenovirus subverts Dlg1 to dysregulate PI3K may serve as a paradigm to understand PI3K activation mediated by other important pathogenic viruses, such as human papillomavirus, human T-cell leukemia virus type 1, and influenza A virus, which also target Dlg1 in infected cells.
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Abstract
Viral and cellular oncogenes converge in targeting critical protein interaction networks to reprogram the cellular DNA and protein replication machinery for pathological replication. In this issue, Thai et al. (2014) show that adenovirus E4ORF1 activates MYC glycolytic targets to induce a Warburg-like effect that converts glucose into nucleotides for viral replication.
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Affiliation(s)
- Shigeki J Miyake-Stoner
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037-1099, USA
| | - Clodagh C O'Shea
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037-1099, USA.
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NTPDASE4 gene products cooperate with the adenovirus E4orf4 protein through PP2A-dependent and -independent mechanisms and contribute to induction of cell death. J Virol 2014; 88:6318-28. [PMID: 24672025 DOI: 10.1128/jvi.00381-14] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
UNLABELLED The adenovirus E4orf4 protein induces nonclassical apoptosis in mammalian cells through at least two complementing pathways regulated by the interactions of E4orf4 with protein phosphatase 2A (PP2A) and Src kinases. In Saccharomyces cerevisiae cells, which do not express Src, E4orf4 induces PP2A-dependent toxicity. The yeast Golgi apyrase Ynd1 was found to contribute to E4orf4-mediated toxicity and to interact with the PP2A-B55α regulatory subunit. In addition, a mammalian Ynd1 orthologue, the NTPDASE4 gene product Golgi UDPase, was shown to physically interact with E4orf4. Here we report that knockdown of NTPDASE4 suppressed E4orf4-induced cell death. Conversely, overexpression of the NTPDASE4 gene products Golgi UDPase and LALP70 enhanced E4orf4-induced cell killing. We found that similarly to results obtained in yeast, the apyrase activity of mammalian UDPase was not required for its contribution to E4orf4-induced toxicity. The interaction between E4orf4 and UDPase had two consequences: a PP2A-dependent one, resulting in increased UDPase levels, and a PP2A-independent outcome that led to dissociation of large UDPase-containing protein complexes. The present report extends our findings in yeast to E4orf4-mediated death of mammalian cells, and combined with previous results, it suggests that the E4orf4-NTPDase4 pathway, partly in association with PP2A, may provide an alternative mechanism for the E4orf4-Src pathway to contribute to the cytoplasmic death function of E4orf4. IMPORTANCE The adenovirus E4orf4 protein contributes to regulation of the progression of virus infection from the early to the late phase, and when expressed alone, it induces a unique caspase-independent programmed cell death which is more efficient in cancer cells than in normal cells. The interactions of E4orf4 with cellular proteins that mediate its functions, such as PP2A and Src kinases, are highly conserved in evolution. The results presented here reveal that the NTPDASE4 gene product Golgi UDPase, first discovered to contribute to E4orf4 toxicity in Saccharomyces cerevisiae, associates with E4orf4 and plays a role in induction of cell death in mammalian cells. Details of the functional interaction between E4orf4, PP2A, and the UDPase are described. Identification of the evolutionarily conserved mechanisms underlying E4orf4 activity will increase our understanding of the interactions between the virus and the host cell and will contribute to our grasp of the unique mode of E4orf4-induced cell death.
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