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Caetano BFR, Rocha VL, Rossini BC, Dos Santos LD, Elgui De Oliveira D. Epstein-Barr Virus miR-BARTs 7 and 9 modulate viral cycle, cell proliferation, and proteomic profiles in Burkitt lymphoma. Tumour Virus Res 2023; 17:200276. [PMID: 38159643 PMCID: PMC11000110 DOI: 10.1016/j.tvr.2023.200276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 12/26/2023] [Indexed: 01/03/2024] Open
Abstract
The Epstein-Barr Virus (EBV) encodes viral microRNAs (miRs) that have been implicated in the pathogenesis of nasopharyngeal and gastric carcinomas, yet their potential roles in lymphomas remain to be fully elucidated. This study evaluated the impact of CRISPR/Cas9-mediated knockdown of EBV miRs BART-7 and BART-9 in EBV-positive Burkitt lymphoma cells Akata. As anticipated, the Akata cells subjected to CRISPR/Cas9-mediated knockdown of either EBV BART-7 or BART-9 exhibited a significant reduction in the expression of these viral miRs compared to cells with wild-type (wt) EBV genomes. This outcome effectively validates the experimental model employed in this study. Knocking down either BART-7 or BART-9 resulted in a notable reduction in cell viability and proliferation rates, alongside an elevation in the expression of EBV lytic genes. Global proteomic analysis revealed that the knockdown of EBV BART-7 significantly decreased the expression of ubiquitin/proteasome proteins while concurrently increasing RNA binding proteins (RBPs). Conversely, BART-9 knockdown reduced proteins associated with oxidoreductase activity, particularly those involved in fatty acid metabolism. Our findings unveil previously undiscovered EBV miRs BARTs 7 and 9 roles in cellular pathways relevant to both viral biology and lymphomagenesis.
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Affiliation(s)
- Brunno Felipe Ramos Caetano
- São Paulo State University (UNESP), Department of Pathology, Botucatu Medical School, Av. Prof. Dr. Mário Rubens Guimarães Montenegro S/n, CEP 18618-687, Botucatu, São Paulo, Brazil; São Paulo State University (UNESP), Institute of Biotechnology (IBTEC), Alameda Das Tecomarias S/n, CEP 18607-440, Botucatu, São Paulo, Brazil.
| | - Viviana Loureiro Rocha
- São Paulo State University (UNESP), Institute of Biotechnology (IBTEC), Alameda Das Tecomarias S/n, CEP 18607-440, Botucatu, São Paulo, Brazil; São Paulo State University (UNESP), Institute of Biosciences (IBB). R. Prof. Dr. Antônio Celso Wagner Zanin, 250, CEP 18618-689, Botucatu, São Paulo, Brazil.
| | - Bruno Cesar Rossini
- São Paulo State University (UNESP), Institute of Biotechnology (IBTEC), Alameda Das Tecomarias S/n, CEP 18607-440, Botucatu, São Paulo, Brazil.
| | - Lucilene Delazari Dos Santos
- São Paulo State University (UNESP), Institute of Biotechnology (IBTEC), Alameda Das Tecomarias S/n, CEP 18607-440, Botucatu, São Paulo, Brazil.
| | - Deilson Elgui De Oliveira
- São Paulo State University (UNESP), Department of Pathology, Botucatu Medical School, Av. Prof. Dr. Mário Rubens Guimarães Montenegro S/n, CEP 18618-687, Botucatu, São Paulo, Brazil; São Paulo State University (UNESP), Institute of Biotechnology (IBTEC), Alameda Das Tecomarias S/n, CEP 18607-440, Botucatu, São Paulo, Brazil.
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Oswald J, Constantine M, Adegbuyi A, Omorogbe E, Dellomo AJ, Ehrlich ES. E3 Ubiquitin Ligases in Gammaherpesviruses and HIV: A Review of Virus Adaptation and Exploitation. Viruses 2023; 15:1935. [PMID: 37766341 PMCID: PMC10535929 DOI: 10.3390/v15091935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/10/2023] [Accepted: 09/12/2023] [Indexed: 09/29/2023] Open
Abstract
For productive infection and replication to occur, viruses must control cellular machinery and counteract restriction factors and antiviral proteins. Viruses can accomplish this, in part, via the regulation of cellular gene expression and post-transcriptional and post-translational control. Many viruses co-opt and counteract cellular processes via modulation of the host post-translational modification machinery and encoding or hijacking kinases, SUMO ligases, deubiquitinases, and ubiquitin ligases, in addition to other modifiers. In this review, we focus on three oncoviruses, Epstein-Barr virus (EBV), Kaposi's sarcoma herpesvirus (KSHV), and human immunodeficiency virus (HIV) and their interactions with the ubiquitin-proteasome system via viral-encoded or cellular E3 ubiquitin ligase activity.
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Affiliation(s)
| | | | | | | | | | - Elana S. Ehrlich
- Department of Biological Sciences, Towson University, Towson, MD 21252, USA
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3
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Abstract
Epstein-Barr virus (EBV) is the first human DNA tumor virus identified from African Burkitt's lymphoma cells. EBV causes ~200,000 various cancers world-wide each year. EBV-associated cancers express latent EBV proteins, EBV nuclear antigens (EBNAs), and latent membrane proteins (LMPs). EBNA1 tethers EBV episomes to the chromosome during mitosis to ensure episomes are divided evenly between daughter cells. EBNA2 is the major EBV latency transcription activator. It activates the expression of other EBNAs and LMPs. It also activates MYC through enhancers 400-500 kb upstream to provide proliferation signals. EBNALP co-activates with EBNA2. EBNA3A/C represses CDKN2A to prevent senescence. LMP1 activates NF-κB to prevent apoptosis. The coordinated activity of EBV proteins in the nucleus allows efficient transformation of primary resting B lymphocytes into immortalized lymphoblastoid cell lines in vitro.
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Affiliation(s)
- Bo Zhao
- Department of Medicine, Division of Infectious Diseases, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA
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4
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Wang C, Liu X, Liang J, Narita Y, Ding W, Li D, Zhang L, Wang H, Leong MML, Hou I, Gerdt C, Jiang C, Zhong Q, Tang Z, Forney C, Kottyan L, Weirauch MT, Gewurz BE, Zeng MS, Jiang S, Teng M, Zhao B. A DNA tumor virus globally reprograms host 3D genome architecture to achieve immortal growth. Nat Commun 2023; 14:1598. [PMID: 36949074 PMCID: PMC10033825 DOI: 10.1038/s41467-023-37347-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 03/13/2023] [Indexed: 03/24/2023] Open
Abstract
Epstein-Barr virus (EBV) immortalization of resting B lymphocytes (RBLs) to lymphoblastoid cell lines (LCLs) models human DNA tumor virus oncogenesis. RBL and LCL chromatin interaction maps are compared to identify the spatial and temporal genome architectural changes during EBV B cell transformation. EBV induces global genome reorganization where contact domains frequently merge or subdivide during transformation. Repressed B compartments in RBLs frequently switch to active A compartments in LCLs. LCLs gain 40% new contact domain boundaries. Newly gained LCL boundaries have strong CTCF binding at their borders while in RBLs, the same sites have much less CTCF binding. Some LCL CTCF sites also have EBV nuclear antigen (EBNA) leader protein EBNALP binding. LCLs have more local interactions than RBLs at LCL dependency factors and super-enhancer targets. RNA Pol II HiChIP and FISH of RBL and LCL further validate the Hi-C results. EBNA3A inactivation globally alters LCL genome interactions. EBNA3A inactivation reduces CTCF and RAD21 DNA binding. EBNA3C inactivation rewires the looping at the CDKN2A/B and AICDA loci. Disruption of a CTCF site at AICDA locus increases AICDA expression. These data suggest that EBV controls lymphocyte growth by globally reorganizing host genome architecture to facilitate the expression of key oncogenes.
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Affiliation(s)
- Chong Wang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
- Department of Diagnostic and Biological Sciences, School of Dentistry, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Xiang Liu
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 33612, USA
| | - Jun Liang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Yohei Narita
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Weiyue Ding
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Difei Li
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Luyao Zhang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Hongbo Wang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Merrin Man Long Leong
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Isabella Hou
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Catherine Gerdt
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Chang Jiang
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
- Department of Cancer Physiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 33612, USA
| | - Qian Zhong
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Zhonghui Tang
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510060, China
| | - Carmy Forney
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Leah Kottyan
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Matthew T Weirauch
- Center for Autoimmune Genomics and Etiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Benjamin E Gewurz
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA
| | - Mu-Sheng Zeng
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Sizun Jiang
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, 02115, USA.
| | - Mingxiang Teng
- Department of Biostatistics and Bioinformatics, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, 33612, USA.
| | - Bo Zhao
- Division of Infectious Disease, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA, 02115, USA.
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Kassab A, Gupta I, Moustafa AA. Role of E2F transcription factor in Oral cancer: Recent Insight and Advancements. Semin Cancer Biol 2023:S1044-579X(23)00037-8. [PMID: 36924812 DOI: 10.1016/j.semcancer.2023.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 02/27/2023] [Accepted: 03/06/2023] [Indexed: 03/16/2023]
Abstract
The family of mammalian E2F transcription factors (E2Fs) comprise of 8 members (E2F1-E2F8) classified as activators (E2F1-E2F3) and repressors (E2F4-E2F8) primarily regulating the expression of several genes related to cell proliferation, apoptosis and differentiation, mainly in a cell cycle-dependent manner. E2F activity is frequently controlled via the retinoblastoma protein (pRb), cyclins, p53 and the ubiquitin-proteasome pathway. Additionally, genetic or epigenetic changes result in the deregulation of E2F family genes expression altering S phase entry and apoptosis, an important hallmark for the onset and development of cancer. Although studies reveal E2Fs to be involved in several human malignancies, the mechanisms underlying the role of E2Fs in oral cancer lies nascent and needs further investigations. This review focuses on the role of E2Fs in oral cancer and the etiological factors regulating E2Fs activity, which in turn transcriptionally control the expression of their target genes, thus contributing to cell proliferation, metastasis, and drug/therapy resistance. Further, we will discuss therapeutic strategies for E2Fs, which may prevent oral tumor growth, metastasis, and drug resistance.
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Pieroni S, Castelli M, Piobbico D, Ferracchiato S, Scopetti D, Di-Iacovo N, Della-Fazia MA, Servillo G. The Four Homeostasis Knights: In Balance upon Post-Translational Modifications. Int J Mol Sci 2022; 23:ijms232214480. [PMID: 36430960 PMCID: PMC9696182 DOI: 10.3390/ijms232214480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 11/14/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
A cancer outcome is a multifactorial event that comes from both exogenous injuries and an endogenous predisposing background. The healthy state is guaranteed by the fine-tuning of genes controlling cell proliferation, differentiation, and development, whose alteration induces cellular behavioral changes finally leading to cancer. The function of proteins in cells and tissues is controlled at both the transcriptional and translational level, and the mechanism allowing them to carry out their functions is not only a matter of level. A major challenge to the cell is to guarantee that proteins are made, folded, assembled and delivered to function properly, like and even more than other proteins when referring to oncogenes and onco-suppressors products. Over genetic, epigenetic, transcriptional, and translational control, protein synthesis depends on additional steps of regulation. Post-translational modifications are reversible and dynamic processes that allow the cell to rapidly modulate protein amounts and function. Among them, ubiquitination and ubiquitin-like modifications modulate the stability and control the activity of most of the proteins that manage cell cycle, immune responses, apoptosis, and senescence. The crosstalk between ubiquitination and ubiquitin-like modifications and post-translational modifications is a keystone to quickly update the activation state of many proteins responsible for the orchestration of cell metabolism. In this light, the correct activity of post-translational machinery is essential to prevent the development of cancer. Here we summarize the main post-translational modifications engaged in controlling the activity of the principal oncogenes and tumor suppressors genes involved in the development of most human cancers.
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Sun Y, Liu W, Luo B. Functional diversity: update of the posttranslational modification of Epstein-Barr virus coding proteins. Cell Mol Life Sci 2022; 79:590. [PMID: 36376593 DOI: 10.1007/s00018-022-04561-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/26/2022] [Accepted: 09/14/2022] [Indexed: 11/16/2022]
Abstract
Epstein-Barr virus (EBV), a human oncogenic herpesvirus with a typical life cycle consisting of latent phase and lytic phase, is associated with many human diseases. EBV can express a variety of proteins that enable the virus to affect host cell processes and evade host immunity. Additionally, these proteins provide a basis for the maintenance of viral infection, contribute to the formation of tumors, and influence the occurrence and development of related diseases. Posttranslational modifications (PTMs) are chemical modifications of proteins after translation and are very important to guarantee the proper biological functions of these proteins. Studies in the past have intensely investigated PTMs of EBV-encoded proteins. EBV regulates the progression of the latent phase and lytic phase by affecting the PTMs of its encoded proteins, which are critical for the development of EBV-associated human diseases. In this review, we summarize the PTMs of EBV-encoded proteins that have been discovered and studied thus far with focus on their effects on the viral life cycle.
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8
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Tiwari D, Mittal N, Jha HC. Unraveling the links between neurodegeneration and Epstein-Barr virus-mediated cell cycle dysregulation. Curr Res Neurobiol 2022; 3:100046. [PMID: 36685766 PMCID: PMC9846474 DOI: 10.1016/j.crneur.2022.100046] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 01/25/2023] Open
Abstract
The Epstein-Barr virus is a well-known cell cycle modulator. To establish successful infection in the host, EBV alters the cell cycle at multiple steps via antigens such as EBNAs, LMPs, and certain other EBV-encoded transcripts. Interestingly, several recent studies have indicated the possibility of EBV's neurotrophic potential. However, the effects and outcomes of EBV infection in the CNS are under-explored. Additionally, more and more epidemiological evidence implicates the cell-cycle dysregulation in neurodegeneration. Numerous hypotheses which describe the triggers that force post-mitotic neurons to re-enter the cell cycle are prevalent. Apart from the known genetic and epigenetic factors responsible, several reports have shown the association of microbial infections with neurodegenerative pathology. Although, studies implicating the herpesvirus family members in neurodegeneration exist, the involvement of Epstein-Barr virus (EBV), in particular, is under-evaluated. Interestingly, a few clinical studies have reported patients of AD or PD to be seropositive for EBV. Based on the findings mentioned above, in this review, we propose that EBV infection in neurons could drive it towards neurodegeneration through dysregulation of cell-cycle events and induction of apoptosis.
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Affiliation(s)
- Deeksha Tiwari
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, India
| | - Nitish Mittal
- Computational and Systems Biology, Biozentrum, University of Basel, Klingelbergstrasse 50-70, 4056, Basel, Switzerland,Corresponding author.
| | - Hem Chandra Jha
- Department of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, India,Corresponding author.
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Abstract
The retinoblastoma protein (pRb) functions as a cell cycle regulator controlling G1 to S phase transition and plays critical roles in tumour suppression. It is frequently inactivated in various tumours. The functions of pRb are tightly regulated, where post-translational modifications (PTMs) play crucial roles, including phosphorylation, ubiquitination, SUMOylation, acetylation and methylation. Most PTMs on pRb are reversible and can be detected in non-cancerous cells, playing an important role in cell cycle regulation, cell survival and differentiation. Conversely, altered PTMs on pRb can give rise to anomalies in cell proliferation and tumourigenesis. In this review, we first summarize recent findings pertinent to how individual PTMs impinge on pRb functions. As many of these PTMs on pRb were published as individual articles, we also provide insights on the coordination, either collaborations and/or competitions, of the same or different types of PTMs on pRb. Having a better understanding of how pRb is post-translationally modulated should pave the way for developing novel and specific therapeutic strategies to treat various human diseases.
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Affiliation(s)
- Linbin Zhou
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Danny Siu-Chun Ng
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Jason C Yam
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong, China
| | - Li Jia Chen
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong, China
| | - Clement C Tham
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong, China
| | - Chi Pui Pang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong, China
| | - Wai Kit Chu
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
- Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong, China.
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong, China.
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10
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Mahoney KE, Shabanowitz J, Hunt DF. MHC Phosphopeptides: Promising Targets for Immunotherapy of Cancer and Other Chronic Diseases. Mol Cell Proteomics 2021; 20:100112. [PMID: 34129940 PMCID: PMC8724925 DOI: 10.1016/j.mcpro.2021.100112] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 05/11/2021] [Accepted: 06/02/2021] [Indexed: 12/27/2022] Open
Abstract
Major histocompatibility complex-associated peptides have been considered as potential immunotherapeutic targets for many years. MHC class I phosphopeptides result from dysregulated cell signaling pathways that are common across cancers and both viral and bacterial infections. These antigens are recognized by central memory T cells from healthy donors, indicating that they are considered antigenic by the immune system and that they are presented across different individuals and diseases. Based on these responses and the similar dysregulation, phosphorylated antigens are promising candidates for prevention or treatment of different cancers as well as a number of other chronic diseases.
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Affiliation(s)
- Keira E Mahoney
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA
| | - Jeffrey Shabanowitz
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA.
| | - Donald F Hunt
- Department of Chemistry, University of Virginia, Charlottesville, Virginia, USA; Department of Pathology, University of Virginia, Charlottesville, Virginia, USA.
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Dzobo K. The Role of Viruses in Carcinogenesis and Molecular Targeting: From Infection to Being a Component of the Tumor Microenvironment. OMICS 2021; 25:358-371. [PMID: 34037476 DOI: 10.1089/omi.2021.0052] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
About a tenth of all cancers are caused by viruses or associated with viral infection. Recent global events including the coronavirus disease-2019 (COVID-19) pandemic means that human encounter with viruses is increased. Cancer development in individuals with viral infection can take many years after infection, demonstrating that the involvement of viruses in cancer development is a long and complex process. This complexity emanates from individual genetic heterogeneity and the many steps involved in cancer development owing to viruses. The process of tumorigenesis is driven by the complex interaction between several viral factors and host factors leading to the creation of a tumor microenvironment (TME) that is ideal and promotes tumor formation. Viruses associated with human cancers ensure their survival and proliferation through activation of several cellular processes including inflammation, migration, and invasion, resistance to apoptosis and growth suppressors. In addition, most human oncoviruses evade immune detection and can activate signaling cascades including the PI3K-Akt-mTOR, Notch and Wnt pathways associated with enhanced proliferation and angiogenesis. This expert review examines and synthesizes the multiple biological factors related to oncoviruses, and the signaling cascades activated by these viruses contributing to viral oncogenesis. In particular, I examine and review the Epstein-Barr virus, human papillomaviruses, and Kaposi's sarcoma herpes virus in a context of cancer pathogenesis. I conclude with a future outlook on therapeutic targeting of the viruses and their associated oncogenic pathways within the TME. These anticancer strategies can be in the form of, but not limited to, antibodies and inhibitors.
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Affiliation(s)
- Kevin Dzobo
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town Component, Cape Town, South Africa.,Division of Medical Biochemistry and Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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12
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Ohashi M, Hayes M, McChesney K, Johannsen E. Epstein-Barr virus nuclear antigen 3C (EBNA3C) interacts with the metabolism sensing C-terminal binding protein (CtBP) repressor to upregulate host genes. PLoS Pathog 2021; 17:e1009419. [PMID: 33720992 PMCID: PMC7993866 DOI: 10.1371/journal.ppat.1009419] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 03/25/2021] [Accepted: 02/22/2021] [Indexed: 12/04/2022] Open
Abstract
Epstein-Barr virus (EBV) infection is associated with the development of specific types of lymphoma and some epithelial cancers. EBV infection of resting B-lymphocytes in vitro drives them to proliferate as lymphoblastoid cell lines (LCLs) and serves as a model for studying EBV lymphomagenesis. EBV nuclear antigen 3C (EBNA3C) is one of the genes required for LCL growth and previous work has suggested that suppression of the CDKN2A encoded tumor suppressor p16INK4A and possibly p14ARF is central to EBNA3C’s role in this growth transformation. To directly assess whether loss of p16 and/or p14 was sufficient to explain EBNA3C growth effects, we used CRISPR/Cas9 to disrupt specific CDKN2A exons in EBV transformed LCLs. Disruption of p16 specific exon 1α and the p16/p14 shared exon 2 were each sufficient to restore growth in the absence of EBNA3C. Using EBNA3C conditional LCLs knocked out for either exon 1α or 2, we identified EBNA3C induced and repressed genes. By trans-complementing with EBNA3C mutants, we determined specific genes that require EBNA3C interaction with RBPJ or CtBP for their regulation. Unexpectedly, interaction with the CtBP repressor was required not only for repression, but also for EBNA3C induction of many host genes. Contrary to previously proposed models, we found that EBNA3C does not recruit CtBP to the promoters of these genes. Instead, our results suggest that CtBP is bound to these promoters in the absence of EBNA3C and that EBNA3C interaction with CtBP interferes with the repressive function of CtBP, leading to EBNA3C mediated upregulation. Epstein-Barr virus (EBV) is a gammaherpesvirus that establishes lifelong infection in about 95% of adult humans. EBV infection is usually benign, but can rarely result in several different malignancies, particularly lymphomas. EBV infection of resting B-lymphocytes in the laboratory drives them to proliferate as lymphoblastoid cell lines (LCLs), a model for EBV lymphomagenesis. In this manuscript we study how one EBV protein expressed in LCLs, EBNA3C, contributes to B lymphocyte transformation. Prior work has established that EBNA3C turns off the CDKN2A gene, but there is disagreement regarding the relative importance of silencing the two CDKN2A gene products: p14 and p16. Using a CRISPR/Cas9 gene editing strategy we confirm that p16 knock-out rescues LCL growth in the absence of EBNA3C even in the presence of wildtype p14. We then use these knock-out LCLs to identify EBNA3C regulated genes and uncover extensive growth-independent changes in B lymphocytes due to the EBNA3C transcription factor. We also discover an unexpected role for the CtBP repressor protein in EBNA3C gene upregulation. Contrary to prior models, we do not observe CtBP recruitment to target genes by EBNA3C. Instead, our data are consistent with EBNA3C interfering with the ability of pre-bound CtBP to repress genes.
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Affiliation(s)
- Makoto Ohashi
- Department of Medicine, Division of Infectious Diseases, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Oncology, McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Mitchell Hayes
- Department of Oncology, McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Kyle McChesney
- Department of Medicine, Division of Infectious Diseases, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Oncology, McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Eric Johannsen
- Department of Medicine, Division of Infectious Diseases, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Oncology, McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- * E-mail:
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Pei Y, Wong JH, Jha HC, Tian T, Wei Z, Robertson ES. Epstein-Barr Virus Facilitates Expression of KLF14 by Regulating the Cooperative Binding of the E2F-Rb-HDAC Complex in Latent Infection. J Virol 2020; 94:e01209-20. [PMID: 32847849 DOI: 10.1128/JVI.01209-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 08/23/2020] [Indexed: 12/31/2022] Open
Abstract
Epstein-Barr virus (EBV) was discovered as the first human tumor virus more than 50 years ago. EBV infects more than 90% of the human population worldwide and is associated with numerous hematologic malignancies and epithelial malignancies. EBV establishes latent infection in B cells, which is the typical program seen in lymphomagenesis. Understanding EBV-mediated transcription regulatory networks is one of the current challenges that will uncover new insights into the mechanism of viral-mediated lymphomagenesis. Here, we describe the regulatory profiles of several cellular factors (E2F6, E2F1, Rb, HDAC1, and HDAC2) together with EBV latent nuclear antigens using next-generation sequencing (NGS) analysis. Our results show that the E2F-Rb-HDAC complex exhibits similar distributions in genomic regions of EBV-positive cells and is associated with oncogenic super-enhancers involving long-range regulatory regions. Furthermore, EBV latent antigens cooperatively hijack this complex to bind at KLFs gene loci and facilitate KLF14 gene expression in lymphoblastoid cell lines (LCLs). These results demonstrate that EBV latent antigens can function as master regulators of this multisubunit repressor complex (E2F-Rb-HDAC) to reverse its suppressive activities and facilitate downstream gene expression that can contribute to viral-induced lymphomagenesis. These results provide novel insights into targets for the development of new therapeutic interventions for treating EBV-associated lymphomas.IMPORTANCE Epstein-Barr virus (EBV), as the first human tumor virus, infects more than 90% of the human population worldwide and is associated with numerous human cancers. Exploring EBV-mediated transcription regulatory networks is critical to understand viral-associated lymphomagenesis. However, the detailed mechanism is not fully explored. Now we describe the regulatory profiles of the E2F-Rb-HDAC complex together with EBV latent antigens, and we found that EBV latent antigens cooperatively facilitate KLF14 expression by antagonizing this multisubunit repressor complex in EBV-positive cells. This provides potential therapeutic targets for the treatment of EBV-associated cancers.
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14
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Pei Y, Wong JHY, Robertson ES. Targeted Therapies for Epstein-Barr Virus-Associated Lymphomas. Cancers (Basel) 2020; 12:E2565. [PMID: 32916819 DOI: 10.3390/cancers12092565] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 09/05/2020] [Accepted: 09/07/2020] [Indexed: 12/24/2022] Open
Abstract
Simple Summary Epstein-Barr virus (EBV) is the first-discovered and important human tumor virus. It infects more than 90% of human population and induces various lymphomas. Development of specific targeted therapies is very critical for treatment of EBV-induced lymphomas, but it remains a great challenge. In this review, we introduced the current progress of EBV-specific therapies and the promising approaches that can be developed as novel targeted therapies, which involve protective or therapeutic strategies to target these lymphomas on different levels. This work will provide new insights into the development of new targeted therapies against EBV-associated lymphomas. Abstract The Epstein-Barr virus (EBV) is the first human tumor virus identified that can transform quiescent B lymphocytes into lymphoblastoid cell lines (LCLs) in vitro. EBV can establish asymptomatic life-long persistence and is associated with multiple human malignancies, including non-Hodgkin lymphoma and Hodgkin lymphoma, as well as infectious mononucleosis. Although EBV-associated lymphomagenesis has been investigated for over 50 years, viral-mediated transformation is not completely understood, and the development of EBV-specific therapeutic strategies to treat the associated cancers is still a major challenge. However, the rapid development of several novel therapies offers exciting possibilities to target EBV-induced lymphomas. This review highlights targeted therapies with potential for treating EBV-associated lymphomas, including small molecule inhibitors, immunotherapy, cell therapy, preventative and therapeutic vaccines, and other potent approaches, which are novel strategies for controlling, preventing, and treating these viral-induced malignances.
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15
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Ewald PW, Swain Ewald HA. The scope of viral causation of human cancers: interpreting virus density from an evolutionary perspective. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180304. [PMID: 30955500 DOI: 10.1098/rstb.2018.0304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Most known oncogenic viruses of humans use DNA as their genomic material. Research over the past quarter century has revealed that their oncogenicity results largely from direct interference with barriers to oncogenesis. In contrast to viruses that have been accepted causes of particular cancers, candidate viral causes tend to have fewer viral than cellular genomes in the tumours. These low viral loads have caused researchers to conclude that the associated viruses are not primary causes of the associated cancers. Consideration of differential survival, reproduction and infiltration of cells in a tumour suggest, however, that viral loads could be low even when viruses are primary causes of cancer. Resolution of this issue has important implications for human health because medical research tends to be effective at preventing and controlling infectious diseases. Mathematical models may clarify the problem and help guide future research by assessing whether low viral loads are likely outcomes of the differential survival, reproduction, and infiltration of cells in a tumour and, more generally, the extent to which viruses contribute to cancer. This article is part of the theme issue 'Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses'.
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Affiliation(s)
- Paul W Ewald
- Department of Biology, University of Louisville , Louisville, KY 40292 , USA
| | - Holly A Swain Ewald
- Department of Biology, University of Louisville , Louisville, KY 40292 , USA
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16
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Cai Y, Su J, Wang N, Zhao W, Zhu M, Su S. Comprehensive analysis of the ubiquitome in rabies virus-infected brain tissue of Mus musculus. Vet Microbiol 2020; 241:108552. [DOI: 10.1016/j.vetmic.2019.108552] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/11/2019] [Accepted: 12/11/2019] [Indexed: 01/03/2023]
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17
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Gain C, Malik S, Bhattacharjee S, Ghosh A, Robertson ES, Das BB, Saha A. Proteasomal inhibition triggers viral oncoprotein degradation via autophagy-lysosomal pathway. PLoS Pathog 2020; 16:e1008105. [PMID: 32092124 PMCID: PMC7058366 DOI: 10.1371/journal.ppat.1008105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 03/05/2020] [Accepted: 01/28/2020] [Indexed: 12/22/2022] Open
Abstract
Epstein-Barr virus (EBV) nuclear oncoprotein EBNA3C is essential for B-cell transformation and development of several B-cell lymphomas particularly those are generated in an immuno-compromised background. EBNA3C recruits ubiquitin-proteasome machinery for deregulating multiple cellular oncoproteins and tumor suppressor proteins. Although EBNA3C is found to be ubiquitinated at its N-terminal region and interacts with 20S proteasome, the viral protein is surprisingly stable in growing B-lymphocytes. EBNA3C can also circumvent autophagy-lysosomal mediated protein degradation and subsequent antigen presentation for T-cell recognition. Recently, we have shown that EBNA3C enhances autophagy, which serve as a prerequisite for B-cell survival particularly under growth deprivation conditions. We now demonstrate that proteasomal inhibition by MG132 induces EBNA3C degradation both in EBV transformed B-lymphocytes and ectopic-expression systems. Interestingly, MG132 treatment promotes degradation of two EBNA3 family oncoproteins-EBNA3A and EBNA3C, but not the viral tumor suppressor protein EBNA3B. EBNA3C degradation induced by proteasomal inhibition is partially blocked when autophagy-lysosomal pathway is inhibited. In response to proteasomal inhibition, EBNA3C is predominantly K63-linked polyubiquitinated, colocalized with the autophagy-lysosomal fraction in the cytoplasm and participated within p62-LC3B complex, which facilitates autophagy-mediated degradation. We further show that the degradation signal is present at the first 50 residues of the N-terminal region of EBNA3C. Proteasomal inhibition reduces the colony formation ability of this important viral oncoprotein, induces apoptotic cell death and increases transcriptional activation of both latent and lytic gene expression which further promotes viral reactivation from EBV transformed B-lymphocytes. Altogether, this study offers rationale to use proteasome inhibitors as potential therapeutic strategy against multiple EBV associated B-cell lymphomas, where EBNA3C is expressed.
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Affiliation(s)
- Chandrima Gain
- Department of Life Sciences, Presidency University, West Bengal, India
| | - Samaresh Malik
- Department of Life Sciences, Presidency University, West Bengal, India
| | | | - Arijit Ghosh
- Laboratory of Molecular Biology, School of Biological Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, India
| | - Erle S. Robertson
- Department of Otorhinolaryngology Head and Neck Surgery, and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Benu Brata Das
- Laboratory of Molecular Biology, School of Biological Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, India
| | - Abhik Saha
- Department of Life Sciences, Presidency University, West Bengal, India
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18
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Sari G, Okat Z, Sahin A, Karademir B. Proteasome Inhibitors in Cancer Therapy and their Relation to Redox Regulation. Curr Pharm Des 2019; 24:5252-5267. [PMID: 30706779 DOI: 10.2174/1381612825666190201120013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 01/25/2019] [Indexed: 01/23/2023]
Abstract
Redox homeostasis is important for the maintenance of cell survival. Under physiological conditions, redox system works in a balance and involves activation of many signaling molecules. Regulation of redox balance via signaling molecules is achieved by different pathways and proteasomal system is a key pathway in this process. Importance of proteasomal system on signaling pathways has been investigated for many years. In this direction, many proteasome targeting molecules have been developed. Some of them are already in the clinic for cancer treatment and some are still under investigation to highlight underlying mechanisms. Although there are many studies done, molecular mechanisms of proteasome inhibitors and related signaling pathways need more detailed explanations. This review aims to discuss redox status and proteasomal system related signaling pathways. In addition, cancer therapies targeting proteasomal system and their effects on redox-related pathways have been summarized.
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Affiliation(s)
- Gulce Sari
- Department of Biochemistry, Faculty of Medicine / Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey.,Department of Genetics and Bioengineering, Faculty of Engineering, Okan University, 34959, Tuzla, I stanbul, Turkey
| | - Zehra Okat
- Department of Biochemistry, Faculty of Medicine / Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Ali Sahin
- Department of Biochemistry, Faculty of Medicine / Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Betul Karademir
- Department of Biochemistry, Faculty of Medicine / Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey
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19
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Lang F, Singh RK, Pei Y, Zhang S, Sun K, Robertson ES. EBV epitranscriptome reprogramming by METTL14 is critical for viral-associated tumorigenesis. PLoS Pathog 2019; 15:e1007796. [PMID: 31226160 PMCID: PMC6588254 DOI: 10.1371/journal.ppat.1007796] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/28/2019] [Indexed: 01/07/2023] Open
Abstract
Epstein-Barr virus (EBV) is a ubiquitous oncogenic virus that induces many cancers. N6-Methyladenosine (m6A) modification regulates many cellular processes. We explored the role of m6A in EBV gene regulation and associated cancers. We have comprehensively defined m6A modification of EBV latent and lytic transcripts. Furthermore, m6A modification demonstrated a functional role in regulation of the stability of viral transcripts. The methyltransferase METTL14 was induced at the transcript and protein levels, and knock-down of METTL14 led to decreased expression of latent EBV transcripts. METTL14 was also significantly induced in EBV-positive tumors, promoted growth of EBV-transformed cells and tumors in Xenograft animal models. Mechanistically, the viral-encoded latent oncoprotein EBNA3C activated transcription of METTL14, and directly interacted with METTL14 to promote its stability. This demonstrated that EBV hijacks METTL14 to drive EBV-mediated tumorigenesis. METTL14 is now a new target for development of therapeutics for treatment of EBV-associated cancers.
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Affiliation(s)
- Fengchao Lang
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Rajnish Kumar Singh
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Yonggang Pei
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Shengwei Zhang
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kunfeng Sun
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Erle S Robertson
- Departments of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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20
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Hui KF, Yiu SPT, Tam KP, Chiang AKS. Viral-Targeted Strategies Against EBV-Associated Lymphoproliferative Diseases. Front Oncol 2019; 9:81. [PMID: 30873380 PMCID: PMC6400835 DOI: 10.3389/fonc.2019.00081] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
Epstein-Barr virus (EBV) is strongly associated with a spectrum of EBV-associated lymphoproliferative diseases (EBV-LPDs) ranging from post-transplant lymphoproliferative disorder, B cell lymphomas (e.g., endemic Burkitt lymphoma, Hodgkin lymphoma, and diffuse large B cell lymphoma) to NK or T cell lymphoma (e.g., nasal NK/T-cell lymphoma). The virus expresses a number of latent viral proteins which are able to manipulate cell cycle and cell death processes to promote survival of the tumor cells. Several FDA-approved drugs or novel compounds have been shown to induce killing of some of the EBV-LPDs by inhibiting the function of latent viral proteins or activating the viral lytic cycle from latency. Here, we aim to provide an overview on the mechanisms by which EBV employs to drive the pathogenesis of various EBV-LPDs and to maintain the survival of the tumor cells followed by a discussion on the development of viral-targeted strategies based on the understanding of the patho-mechanisms.
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Affiliation(s)
- Kwai Fung Hui
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Stephanie Pei Tung Yiu
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Kam Pui Tam
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Alan Kwok Shing Chiang
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong.,Center for Nasopharyngeal Carcinoma Research, The University of Hong Kong, Hong Kong, Hong Kong
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21
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Zhang S, Pei Y, Lang F, Sun K, Singh RK, Lamplugh ZL, Saha A, Robertson ES. EBNA3C facilitates RASSF1A downregulation through ubiquitin-mediated degradation and promoter hypermethylation to drive B-cell proliferation. PLoS Pathog 2019; 15:e1007514. [PMID: 30615685 PMCID: PMC6336319 DOI: 10.1371/journal.ppat.1007514] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 01/17/2019] [Accepted: 12/08/2018] [Indexed: 12/15/2022] Open
Abstract
EBV latent antigen 3C (EBNA3C) is essential for EBV-induced primary B-cell transformation. Infection by EBV induces hypermethylation of a number of tumor suppressor genes, which contributes to the development of human cancers. The Ras association domain family isoform 1A (RASSF1A) is a cellular tumor suppressor, which regulates a broad range of cellular functions, including apoptosis, cell-cycle arrest, mitotic arrest, and migration. However, the expression of RASSF1A is lost in many human cancers by epigenetic silencing. In the present study, we showed that EBNA3C promoted B-cell transformation by specifically suppressing the expression of RASSF1A. EBNA3C directly interacted with RASSF1A and induced RASSF1A degradation via the ubiquitin-proteasome-dependent pathway. SCFSkp2, an E3-ubiquitin ligase, was recruited by EBNA3C to enhance RASSF1A degradation. Moreover, EBNA3C decreased the transcriptional activity of RASSF1A promoter by enhancing its methylation through EBNA3C-mediated modulation of DNMTs expression. EBNA3C also inhibited RASSF1A-mediated cell apoptosis, disrupted RASSF1A-mediated microtubule and chromosomal stability, and promoted cell proliferation by upregulating Cyclin D1 and Cyclin E expression. Our data provides new details, which sheds light on additional mechanisms by which EBNA3C can induce B-cell transformation. This will also facilitate the development of novel therapeutic approaches through targeting of the RASSF1A pathway.
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Affiliation(s)
- Shengwei Zhang
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Fengchao Lang
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Kunfeng Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Rajnish Kumar Singh
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zachary L. Lamplugh
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Abhik Saha
- Department of Life Sciences, Presidency University, Kolkata, India
| | - Erle S. Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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22
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Abstract
Herpesvirus-induced disease is one of the most lethal factors which leads to high mortality in HIV/AIDS patients. EBV, also known as human herpesvirus 4, can transform naive B cells into immortalized cells in vitro through the regulation of cell cycle, cell proliferation, and apoptosis. EBV infection is associated with several lymphoma and epithelial cancers in humans, which occurs at a much higher rate in immune deficient individuals than in healthy people, demonstrating that the immune system plays a vital role in inhibiting EBV activities. EBV latency infection proteins can mimic suppression cytokines or upregulate PD-1 on B cells to repress the cytotoxic T cells response. Many malignancies, including Hodgkin Lymphoma and non-Hodgkin's lymphomas occur at a much higher frequency in EBV positive individuals than in EBV negative people during the development of HIV infection. Importantly, understanding EBV pathogenesis at the molecular level will aid the development of novel therapies for EBV-induced diseases in HIV/AIDS patients.
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Affiliation(s)
- Fengchao Lang
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology and Global Cancer Programs, Abramson Cancer Center, Philadelphia, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology and Global Cancer Programs, Abramson Cancer Center, Philadelphia, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Zachary L Lamplugh
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology and Global Cancer Programs, Abramson Cancer Center, Philadelphia, USA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Erle S Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology and Global Cancer Programs, Abramson Cancer Center, Philadelphia, USA. .,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA. .,, 3610 Hamilton Walk, 201E Johnson Pavilion, Philadelphia, PA, 19104, USA.
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Dybas JM, Herrmann C, Weitzman MD. Ubiquitination at the interface of tumor viruses and DNA damage responses. Curr Opin Virol 2018; 32:40-7. [PMID: 30261451 DOI: 10.1016/j.coviro.2018.08.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 08/31/2018] [Indexed: 01/09/2023]
Abstract
Viruses exploit cellular ubiquitination machinery to shape the host proteome and promote productive infection. Among the cellular processes influenced by viral manipulation of ubiquitination is the DNA damage response (DDR), a network of cellular signaling pathways that sense and respond to genomic damage. This host-pathogen interaction is particularly important during virus replication and transformation by DNA tumor viruses. Manipulating DDR pathways can promote virus replication but also impacts host genomic instability, potentially leading to cellular transformation and tumor formation. We review ways in which viruses are known to hijack the cellular ubiquitin system to reshape host DDR pathways.
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24
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Pei Y, Singh RK, Shukla SK, Lang F, Zhang S, Robertson ES. Epstein-Barr Virus Nuclear Antigen 3C Facilitates Cell Proliferation by Regulating Cyclin D2. J Virol 2018; 92:e00663-18. [PMID: 29997218 DOI: 10.1128/JVI.00663-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 07/03/2018] [Indexed: 02/06/2023] Open
Abstract
Cell cycle regulation is one of the hallmarks of virus-mediated oncogenesis. Epstein-Barr virus (EBV)-induced lymphomas express a repertoire of essential viral latent proteins that regulate expression of cell cycle-related proteins to dysregulate this process, thereby facilitating the proliferation of infected cells. We now demonstrate that the essential EBV latent protein 3C (EBNA3C) stabilizes cyclin D2 to regulate cell cycle progression. More specifically, EBNA3C directly binds to cyclin D2 and they colocalize together in nuclear compartments. We show that EBNA3C regulates the promoter of cyclin D2 through cooperation with master transcription factor Bcl6 and enhances its stability by inhibiting its ubiquitin-dependent degradation. EBNA3C also promoted cell proliferation in the presence of cyclin D2, suggesting that cyclin D2 contributes to EBNA3C-mediated cell cycle progression. These results provide new clues as to the role of this essential viral latent protein and its ability to regulate expression of cellular factors, which drives the oncogenic process.IMPORTANCE Epstein-Barr virus (EBV) is the first identified human tumor virus and is associated with a range of human cancers. During EBV-induced lymphomas, the essential viral latent proteins modify the expression of cell cycle-related proteins to disturb the cell cycle process, thereby facilitating the proliferative process. The essential EBV nuclear antigen 3C (EBNA3C) plays an important role in EBV-mediated B-cell transformation. Here we show that EBNA3C stabilizes cyclin D2 to regulate cell cycle progression. More specifically, EBNA3C directly binds to cyclin D2, and they colocalize together in nuclear compartments. EBNA3C enhances cyclin D2 stability by inhibiting its ubiquitin-dependent degradation and significantly promotes cell proliferation in the presence of cyclin D2. Our results provide novel insights into the function of EBNA3C on cell progression by regulating the cyclin D2 protein and raise the possibility of the development of new anticancer therapies against EBV-associated cancers.
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25
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Bhattacharjee S, Bose P, Patel K, Roy SG, Gain C, Gowda H, Robertson ES, Saha A. Transcriptional and epigenetic modulation of autophagy promotes EBV oncoprotein EBNA3C induced B-cell survival. Cell Death Dis 2018; 9:605. [PMID: 29789559 DOI: 10.1038/s41419-018-0668-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 03/26/2018] [Accepted: 04/23/2018] [Indexed: 11/09/2022]
Abstract
Epstein-Barr virus (EBV) oncoprotein EBNA3C is indispensable for primary B-cell transformation and maintenance of lymphoblastoid cells outgrowth. EBNA3C usurps two putative cellular pathways-cell-cycle and apoptosis, essentially through modulating ubiquitin-mediated protein-degradation or gene transcription. In cancer cells, these two pathways are interconnected with autophagy,-a survival-promoting catabolic network in which cytoplasmic material including mis/un-folded protein aggregates and damaged organelles along with intracellular pathogens are degraded and recycled in lysosomal compartments. Studies have shown that tumor viruses including EBV can manipulate autophagy as a survival strategy. Here, we demonstrate that EBNA3C elevates autophagy, which serves as a prerequisite for apoptotic inhibition and maintenance of cell growth. Using PCR based micro-array we show that EBNA3C globally accelerates autophagy gene transcription under growth limiting conditions. Reanalyzing the ENCODE ChIP-sequencing data (GSE52632 and GSE26386) followed by ChIP-PCR demonstrate that EBNA3C recruits several histone activation epigenetic marks (H3K4me1, H3K4me3, H3K9ac, and H3K27ac) for transcriptional activation of autophagy genes, notably ATG3, ATG5, and ATG7 responsible for autophagosome formation. Moreover, under growth limiting conditions EBNA3C further stimulates the autophagic response through upregulation of a number of tumor suppressor genes, notably cyclin-dependent kinase inhibitors-CDKN1B (p27Kip1) and CDKN2A (p16INK4a) and autophagy mediated cell-death modulators-DRAM1 and DAPK1. Together our data highlight a new role of an essential EBV oncoprotein in regulating autophagy cascade as a survival mechanism and offer novel-targets for potential therapeutic expansion against EBV induced B-cell lymphomas.
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26
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Styles CT, Paschos K, White RE, Farrell PJ. The Cooperative Functions of the EBNA3 Proteins Are Central to EBV Persistence and Latency. Pathogens 2018; 7:E31. [PMID: 29562595 DOI: 10.3390/pathogens7010031] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 02/26/2018] [Accepted: 03/07/2018] [Indexed: 02/04/2023] Open
Abstract
The Epstein–Barr nuclear antigen 3 (EBNA3) family of proteins, comprising EBNA3A, EBNA3B, and EBNA3C, play pivotal roles in the asymptomatic persistence and life-long latency of Epstein–Barr virus (EBV) in the worldwide human population. EBNA3-mediated transcriptional reprogramming of numerous host cell genes promotes in vitro B cell transformation and EBV persistence in vivo. Despite structural and sequence similarities, and evidence of substantial cooperative activity between the EBNA3 proteins, they perform quite different, often opposing functions. Both EBNA3A and EBNA3C are involved in the repression of important tumour suppressive pathways and are considered oncogenic. In contrast, EBNA3B exhibits tumour suppressive functions. This review focuses on how the EBNA3 proteins achieve the delicate balance required to support EBV persistence and latency, with emphasis on the contribution of the Allday laboratory to the field of EBNA3 biology.
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Hui KF, Tam KP, Chiang AKS. Therapeutic Strategies against Epstein-Barr Virus-Associated Cancers Using Proteasome Inhibitors. Viruses 2017; 9:E352. [PMID: 29160853 DOI: 10.3390/v9110352] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 12/15/2022] Open
Abstract
Epstein-Barr virus (EBV) is closely associated with several lymphomas (endemic Burkitt lymphoma, Hodgkin lymphoma and nasal NK/T-cell lymphoma) and epithelial cancers (nasopharyngeal carcinoma and gastric carcinoma). To maintain its persistence in the host cells, the virus manipulates the ubiquitin-proteasome system to regulate viral lytic reactivation, modify cell cycle checkpoints, prevent apoptosis and evade immune surveillance. In this review, we aim to provide an overview of the mechanisms by which the virus manipulates the ubiquitin-proteasome system in EBV-associated lymphoid and epithelial malignancies, to evaluate the efficacy of proteasome inhibitors on the treatment of these cancers and discuss potential novel viral-targeted treatment strategies against the EBV-associated cancers.
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Pei Y, Banerjee S, Jha HC, Sun Z, Robertson ES. An essential EBV latent antigen 3C binds Bcl6 for targeted degradation and cell proliferation. PLoS Pathog 2017; 13:e1006500. [PMID: 28738086 PMCID: PMC5524291 DOI: 10.1371/journal.ppat.1006500] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/29/2017] [Indexed: 02/07/2023] Open
Abstract
The latent EBV nuclear antigen 3C (EBNA3C) is required for transformation of primary human B lymphocytes. Most mature B-cell malignancies originate from malignant transformation of germinal center (GC) B-cells. The GC reaction appears to have a role in malignant transformation, in which a major player of the GC reaction is Bcl6, a key regulator of this process. We now demonstrate that EBNA3C contributes to B-cell transformation by targeted degradation of Bcl6. We show that EBNA3C can physically associate with Bcl6. Notably, EBNA3C expression leads to reduced Bcl6 protein levels in a ubiquitin-proteasome dependent manner. Further, EBNA3C inhibits the transcriptional activity of the Bcl6 promoter through interaction with the cellular protein IRF4. Bcl6 degradation induced by EBNA3C rescued the functions of the Bcl6-targeted downstream regulatory proteins Bcl2 and CCND1, which resulted in increased proliferation and G1-S transition. These data provide new insights into the function of EBNA3C in B-cell transformation during GC reaction, and raises the possibility of developing new targeted therapies against EBV-associated cancers.
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Affiliation(s)
- Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Shuvomoy Banerjee
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hem Chandra Jha
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Zhiguo Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Erle S. Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery, and Microbiology, the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Kaplan GS, Torcun CC, Grune T, Ozer NK, Karademir B. Proteasome inhibitors in cancer therapy: Treatment regimen and peripheral neuropathy as a side effect. Free Radic Biol Med 2017; 103:1-13. [PMID: 27940347 DOI: 10.1016/j.freeradbiomed.2016.12.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/22/2016] [Accepted: 12/04/2016] [Indexed: 01/10/2023]
Abstract
Proteasomal system plays an important role in protein turnover, which is essential for homeostasis of cells. Besides degradation of oxidized proteins, it is involved in the regulation of many different signaling pathways. These pathways include mainly cell differentiation, proliferation, apoptosis, transcriptional activation and angiogenesis. Thus, proteasomal system is a crucial target for treatment of several diseases including neurodegenerative diseases, cystic fibrosis, atherosclerosis, autoimmune diseases, diabetes and cancer. Over the last fifteen years, proteasome inhibitors have been tested to highlight their mechanisms of action and used in the clinic to treat different types of cancer. Proteasome inhibitors are mainly used in combinational therapy along with classical chemo-radiotherapy. Several studies have proved their significant effects but serious side effects such as peripheral neuropathy, limits their use in required effective doses. Recent studies focus on peripheral neuropathy as the primary side effect of proteasome inhibitors. Therefore, it is important to delineate the underlying mechanisms of peripheral neuropathy and develop new inhibitors according to obtained data. This review will detail the role of proteasome inhibition in cancer therapy and development of peripheral neuropathy as a side effect. Additionally, new approaches to prevent treatment-limiting side effects will be discussed in order to help researchers in developing effective strategies to overcome side effects of proteasome inhibitors.
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Affiliation(s)
- Gulce Sari Kaplan
- Department of Biochemistry, School of Medicine/Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Ceyda Corek Torcun
- Department of Biochemistry, School of Medicine/Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Tilman Grune
- Department for Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany
| | - Nesrin Kartal Ozer
- Department of Biochemistry, School of Medicine/Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey
| | - Betul Karademir
- Department of Biochemistry, School of Medicine/Genetic and Metabolic Diseases Research and Investigation Center, Marmara University, 34854 Maltepe, Istanbul, Turkey.
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Wang L, Wang Y, Zhao J, Ren J, Hall KH, Moorman JP, Yao ZQ, Ning S. The Linear Ubiquitin Assembly Complex Modulates Latent Membrane Protein 1 Activation of NF-κB and Interferon Regulatory Factor 7. J Virol 2017; 91:e01138-16. [PMID: 27903798 DOI: 10.1128/JVI.01138-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 11/14/2016] [Indexed: 12/11/2022] Open
Abstract
Recently, linear ubiquitin assembly complex (LUBAC)-mediated linear ubiquitination has come into focus due to its emerging role in activation of NF-κB in different biological contexts. However, the role of LUBAC in LMP1 signaling leading to NF-κB and interferon regulatory factor 7 (IRF7) activation has not been investigated. We show here that RNF31, the key component of LUBAC, interacts with LMP1 and IRF7 in Epstein-Barr virus (EBV)-transformed cells and that LUBAC stimulates linear ubiquitination of NEMO and IRF7. Consequently, LUBAC is required for LMP1 signaling to full activation of NF-κB but inhibits LMP1-stimulated IRF7 transcriptional activity. The protein levels of RNF31 and LMP1 are correlated in EBV-transformed cells. Knockdown of RNF31 in EBV-transformed IB4 cells by RNA interference negatively regulates the expression of the genes downstream of LMP1 signaling and results in a decrease of cell proliferation. These lines of evidence indicate that LUBAC-mediated linear ubiquitination plays crucial roles in regulating LMP1 signaling and functions. IMPORTANCE We show here that LUBAC-mediated linear ubiquitination is required for LMP1 activation of NF-κB but inhibits LMP1-mediated IRF7 activation. Our findings provide novel mechanisms underlying EBV-mediated oncogenesis and may have a broad impact on IRF7-mediated immune responses.
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Abstract
Epstein–Barr virus (EBV) was first discovered in 1964, and was the first known human tumor virus now shown to be associated with a vast number of human diseases. Numerous studies have been conducted to understand infection, propagation, and transformation in various cell types linked to human diseases. However, a comprehensive lens through which virus infection, reactivation and transformation of infected host cells can be visualized is yet to be formally established and will need much further investigation. Several human cell types infected by EBV have been linked to associated diseases. However, whether these are a direct result of EBV infection or indirectly due to contributions by additional infectious agents will need to be fully investigated. Therefore, a thorough examination of infection, reactivation, and cell transformation induced by EBV will provide a more detailed view of its contributions that drive pathogenesis. This undoubtedly expand our knowledge of the biology of EBV infection and the signaling activities of targeted cellular factors dysregulated on infection. Furthermore, these insights may lead to identification of therapeutic targets and agents for clinical interventions. Here, we review the spectrum of EBV-associated diseases, the role of the encoded latent antigens, and the switch to latency or lytic replication which occurs in EBV infected cells. Furthermore, we describe the cellular processes and critical factors which contribute to cell transformation. We also describe the fate of B-cells and epithelial cells after EBV infection and the expected consequences which contribute to establishment of viral-associated pathologies.
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Affiliation(s)
- Hem C Jha
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
| | - Yonggang Pei
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
| | - Erle S Robertson
- Department of Otorhinolaryngology-Head and Neck Surgery and Tumor Virology Program, Abramson Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia PA, USA
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Abstract
The orchestrated crosstalk between the retinoblastoma (RB) and p53 pathways contributes to preserving proper homeostasis within the cell. The deregulation of one or both pathways is a common factor in the development of most types of human cancer. The proto-oncoproteins MDMX and MDM2 are the main regulators of the well- known tumor suppressor p53 protein. Under normal conditions, MDM2 and MDMX inhibit p53, either via repression of its transcriptional activity by protein-protein interaction, or via polyubiquitination as a result of MDM2-E3 ubiquitin ligase activity, for which MDM2 needs to dimerize with MDMX. Under genotoxic stress conditions, both become positive regulators of p53. The ATM-dependent phosphorylation of MDM2 and MDMX allow them to bind p53 mRNA, these interactions promote p53 translation. MDM2 and MDMX are also being revealed as effective regulators of the RB protein. MDM2 is able to degrade RB by two different mechanisms, that is, by ubiquitin dependent and independent pathways. MDMX enhances the ability of MDM2 to bind and degrade RB protein. However, MDMX also seems to stabilize RB through interaction and competition with MDM2. Here, we will contextualize the findings that suggest that the MDM2 and MDMX proteins have a dual function on both p53 and RB.
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Affiliation(s)
- Jesús Hernández-Monge
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Av Manuel Nava No 6 Zona Universitaria CP 78290. SLP, México
| | - Adriana Berenice Rousset-Roman
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Av Manuel Nava No 6 Zona Universitaria CP 78290. SLP, México
| | - Ixaura Medina-Medina
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Av Manuel Nava No 6 Zona Universitaria CP 78290. SLP, México
| | - Vanesa Olivares-Illana
- Instituto de Física, Universidad Autónoma de San Luis Potosí, Av Manuel Nava No 6 Zona Universitaria CP 78290. SLP, México
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Ramanujan A, Tiwari S. APC/C and retinoblastoma interaction: cross-talk of retinoblastoma protein with the ubiquitin proteasome pathway. Biosci Rep 2016; 36:e00377. [PMID: 27402801 DOI: 10.1042/BSR20160152] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 07/08/2016] [Indexed: 12/15/2022] Open
Abstract
The ubiquitin (Ub) ligase anaphase promoting complex/cyclosome (APC/C) and the tumour suppressor retinoblastoma protein (pRB) play key roles in cell cycle regulation. APC/C is a critical regulator of mitosis and G1-phase of the cell cycle whereas pRB keeps a check on proliferation by inhibiting transition to the S-phase. APC/C and pRB interact with each other via the co-activator of APC/C, FZR1, providing an alternative pathway of regulation of G1 to S transition by pRB using a post-translational mechanism. Both pRB and FZR1 have complex roles and are implicated not only in regulation of cell proliferation but also in differentiation, quiescence, apoptosis, maintenance of chromosomal integrity and metabolism. Both are also targeted by transforming viruses. We discuss recent advances in our understanding of the involvement of APC/C and pRB in cell cycle based decisions and how these insights will be useful for development of anti-cancer and anti-viral drugs.
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Gan J, Qiao N, Strahan R, Zhu C, Liu L, Verma SC, Wei F, Cai Q. Manipulation of ubiquitin/SUMO pathways in human herpesviruses infection. Rev Med Virol 2016; 26:435-445. [DOI: 10.1002/rmv.1900] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/03/2016] [Accepted: 07/25/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Jin Gan
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College; Fudan University; Shanghai China
| | - Niu Qiao
- Department of Medical Systems Biology, School of Basic Medical Sciences; Department of Translational Medicine, Shanghai Public Health Clinical Center; Institutes of Biomedical Sciences, Fudan University; Shanghai China
| | - Roxanne Strahan
- Department of Microbiology & Immunology; University of Nevada, Reno School of Medicine; Reno NV USA
| | - Caixia Zhu
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College; Fudan University; Shanghai China
| | - Lei Liu
- Department of Medical Systems Biology, School of Basic Medical Sciences; Department of Translational Medicine, Shanghai Public Health Clinical Center; Institutes of Biomedical Sciences, Fudan University; Shanghai China
| | - Subhash C. Verma
- Department of Microbiology & Immunology; University of Nevada, Reno School of Medicine; Reno NV USA
| | - Fang Wei
- ShengYushou Center of Cell Biology and Immunology, School of Life Sciences and Biotechnology; Shanghai Jiao Tong University; Shanghai China
| | - Qiliang Cai
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College; Fudan University; Shanghai China
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Bhattacharjee S, Ghosh Roy S, Bose P, Saha A. Role of EBNA-3 Family Proteins in EBV Associated B-cell Lymphomagenesis. Front Microbiol 2016; 7:457. [PMID: 27092119 PMCID: PMC4824013 DOI: 10.3389/fmicb.2016.00457] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/21/2016] [Indexed: 12/28/2022] Open
Abstract
Epstein-Barr virus (EBV) is highly ubiquitous in human population and establishes a lifelong asymptomatic infection within the infected host unless the immune system is compromised. Following initial infection in the oropharyngeal epithelial cells, EBV primarily infects naive B-lymphocytes and develops a number of B-cell lymphomas particularly in immune-deficient individuals. In vitro, EBV can also infect and subsequently transform quiescent B-lymphocytes into continuously proliferating lymphoblastoid cell lines (LCLs) resembling EBV-induced lymphoproliferative disorders in which a subset of latent transcripts are detected. Genetic studies revealed that EBNA-3 family comprising of three adjacent genes in the viral genome-EBNA-3A and -3C, but not -3B, are critical for B-cell transformation. Nevertheless, all three proteins appear to significantly contribute to maintain the overall proliferation and viability of transformed cells, suggesting a critical role in lymphoma development. Apart from functioning as important viral transcriptional regulators, EBNA-3 proteins associate with many cellular proteins in different signaling networks, providing a suitable platform for lifelong survival of the virus and concurrent lymphoma development in the infected host. The chapter describes the function of each these EBV nuclear antigen 3 proteins employed by the virus as a means to understand viral pathogenesis of several EBV-associated B-cell malignancies.
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Affiliation(s)
| | | | - Priyanka Bose
- Department of Biological Sciences, Presidency University Kolkata, India
| | - Abhik Saha
- Department of Biological Sciences, Presidency University Kolkata, India
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Kawatsuki A, Yasunaga JI, Mitobe Y, Green PL, Matsuoka M. HTLV-1 bZIP factor protein targets the Rb/E2F-1 pathway to promote proliferation and apoptosis of primary CD4(+) T cells. Oncogene 2016; 35:4509-17. [PMID: 26804169 DOI: 10.1038/onc.2015.510] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 11/18/2015] [Accepted: 12/04/2015] [Indexed: 12/13/2022]
Abstract
Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus that induces a fatal T-cell malignancy, adult T-cell leukemia (ATL). Among several regulatory/accessory genes in HTLV-1, HTLV-1 bZIP factor (HBZ) is the only viral gene constitutively expressed in infected cells. Our previous study showed that HBZ functions in two different molecular forms, HBZ protein and HBZ RNA. In this study, we show that HBZ protein targets retinoblastoma protein (Rb), which is a critical tumor suppressor in many types of cancers. HBZ protein interacts with the Rb/E2F-1 complex and activates the transcription of E2F-target genes associated with cell cycle progression and apoptosis. Mouse primary CD4(+) T cells transduced with HBZ show accelerated G1/S transition and apoptosis, and importantly, T cells from HBZ transgenic (HBZ-Tg) mice also demonstrate enhanced cell proliferation and apoptosis. To evaluate the functions of HBZ protein alone in vivo, we generated a new transgenic mouse strain that expresses HBZ mRNA altered by silent mutations but encoding intact protein. In these mice, the numbers of effector/memory and Foxp3(+) T cells were increased, and genes associated with proliferation and apoptosis were upregulated. This study shows that HBZ protein promotes cell proliferation and apoptosis in primary CD4(+) T cells through activation of the Rb/E2F pathway, and that HBZ protein also confers onto CD4(+) T-cell immunophenotype similar to those of ATL cells, suggesting that HBZ protein has important roles in dysregulation of CD4(+) T cells infected with HTLV-1.
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Wang Y, Zheng Z, Zhang J, Wang Y, Kong R, Liu J, Zhang Y, Deng H, Du X, Ke Y. A Novel Retinoblastoma Protein (RB) E3 Ubiquitin Ligase (NRBE3) Promotes RB Degradation and Is Transcriptionally Regulated by E2F1 Transcription Factor. J Biol Chem 2015; 290:28200-28213. [PMID: 26442585 DOI: 10.1074/jbc.m115.655597] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Indexed: 12/25/2022] Open
Abstract
Retinoblastoma protein (RB) plays critical roles in tumor suppression and is degraded through the proteasomal pathway. However, E3 ubiquitin ligases responsible for proteasome-mediated degradation of RB are largely unknown. Here we characterize a novel RB E3 ubiquitin ligase (NRBE3) that binds RB and promotes RB degradation. NRBE3 contains an LXCXE motif and bound RB in vitro. NRBE3 interacted with RB in cells when proteasome activity was inhibited. NRBE3 promoted RB ubiquitination and degradation via the ubiquitin-proteasome pathway. Importantly, purified NRBE3 ubiquitinated recombinant RB in vitro, and a U-box was identified as essential for its E3 activity. Surprisingly, NRBE3 was transcriptionally activated by E2F1/DP1. Consequently, NRBE3 affected the cell cycle by promoting G1/S transition. Moreover, NRBE3 was up-regulated in breast cancer tissues. Taken together, we identified NRBE3 as a novel ubiquitin E3 ligase for RB that might play a role as a potential oncoprotein in human cancers.
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Affiliation(s)
- Yingshuang Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Genetics Laboratory, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing 100142, China
| | - Zongfang Zheng
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Genetics Laboratory, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing 100142, China
| | - Jingyi Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education)
| | - You Wang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Genetics Laboratory, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing 100142, China
| | - Ruirui Kong
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Genetics Laboratory, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing 100142, China
| | - Jiangying Liu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Genetics Laboratory, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing 100142, China
| | - Ying Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Genetics Laboratory, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing 100142, China
| | - Hongkui Deng
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xiaojuan Du
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Department of Cell Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China.
| | - Yang Ke
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education); Genetics Laboratory, Peking University School of Oncology, Beijing Cancer Hospital and Institute, Beijing 100142, China
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Sengupta S, Henry RW. Regulation of the retinoblastoma–E2F pathway by the ubiquitin–proteasome system. Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms 2015; 1849:1289-97. [DOI: 10.1016/j.bbagrm.2015.08.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/18/2015] [Accepted: 08/20/2015] [Indexed: 12/16/2022]
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Pease NA, Wise-Draper T, Privette Vinnedge L. Dissecting the Potential Interplay of DEK Functions in Inflammation and Cancer. J Oncol 2015; 2015:106517. [PMID: 26425120 DOI: 10.1155/2015/106517] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 03/05/2015] [Indexed: 12/12/2022]
Abstract
There is a long-standing correlation between inflammation, inflammatory cell signaling pathways, and tumor formation. Understanding the mechanisms behind inflammation-driven tumorigenesis is of great research and clinical importance. Although not entirely understood, these mechanisms include a complex interaction between the immune system and the damaged epithelium that is mediated by an array of molecular signals of inflammation—including reactive oxygen species (ROS), cytokines, and NFκB signaling—that are also oncogenic. Here, we discuss the association of the unique DEK protein with these processes. Specifically, we address the role of DEK in chronic inflammation via viral infections and autoimmune diseases, the overexpression and oncogenic activity of DEK in cancers, and DEK-mediated regulation of NFκB signaling. Combined, evidence suggests that DEK may play a complex, multidimensional role in chronic inflammation and subsequent tumorigenesis.
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Abstract
Latent Epstein–Barr virus (EBV) infection has a substantial role in causing many human disorders. The persistence of these viral genomes in all malignant cells, yet with the expression of limited latent genes, is consistent with the notion that EBV latent genes are important for malignant cell growth. While the EBV-encoded nuclear antigen-1 (EBNA-1) and latent membrane protein-2A (LMP-2A) are critical, the EBNA-leader proteins, EBNA-2, EBNA-3A, EBNA-3C and LMP-1, are individually essential for in vitro transformation of primary B cells to lymphoblastoid cell lines. EBV-encoded RNAs and EBNA-3Bs are dispensable. In this review, the roles of EBV latent genes are summarized.
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Affiliation(s)
- Myung-Soo Kang
- 1] Samsung Advanced Institute for Health Sciences and Technology (SAIHST), Samsung Medical Center, Sungkyunkwan University, Seoul, Korea [2] Samsung Biomedical Research Institute (SBRI), Samsung Medical Center, Sungkyunkwan University, Seoul, Korea
| | - Elliott Kieff
- Department of Medicine, Brigham and Women's Hospital, Program in Virology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
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Allday MJ, Bazot Q, White RE. The EBNA3 Family: Two Oncoproteins and a Tumour Suppressor that Are Central to the Biology of EBV in B Cells. Curr Top Microbiol Immunol 2015; 391:61-117. [PMID: 26428372 DOI: 10.1007/978-3-319-22834-1_3] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Epstein-Barr virus nuclear antigens EBNA3A , EBNA3B and EBNA3C are a family of three large latency-associated proteins expressed in B cells induced to proliferate by the virus. Together with the other nuclear antigens (EBNA-LP, EBNA2 and EBNA1), they are expressed from a polycistronic transcription unit that is probably unique to B cells. However, compared with the other EBNAs, hitherto the EBNA3 proteins were relatively neglected and their roles in EBV biology rather poorly understood. In recent years, powerful new technologies have been used to show that these proteins are central to the latency of EBV in B cells, playing major roles in reprogramming the expression of host genes affecting cell proliferation, survival, differentiation and immune surveillance. This indicates that the EBNA3s are critical in EBV persistence in the B cell system and in modulating B cell lymphomagenesis. EBNA3A and EBNA3C are necessary for the efficient proliferation of EBV-infected B cells because they target important tumour suppressor pathways--so operationally they are considered oncoproteins. In contrast, it is emerging that EBNA3B restrains the oncogenic capacity of EBV, so it can be considered a tumour suppressor--to our knowledge the first to be described in a tumour virus. Here, we provide a general overview of the EBNA3 genes and proteins. In particular, we describe recent research that has highlighted the complexity of their functional interactions with each other, with specific sites on the human genome and with the molecular machinery that controls transcription and epigenetic states of diverse host genes.
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Abstract
Approximately 12% of all human cancers are caused by oncoviruses. Human viral oncogenesis is complex, and only a small percentage of the infected individuals develop cancer, often many years to decades after the initial infection. This reflects the multistep nature of viral oncogenesis, host genetic variability, and the fact that viruses contribute to only a portion of the oncogenic events. In this review, the Hallmarks of Cancer framework of Hanahan and Weinberg (2000 and 2011) is used to dissect the viral, host, and environmental cofactors that contribute to the biology of multistep oncogenesis mediated by established human oncoviruses. The viruses discussed include Epstein-Barr virus (EBV), high-risk human papillomaviruses (HPVs), hepatitis B and C viruses (HBV and HCV, respectively), human T cell lymphotropic virus-1 (HTLV-1), and Kaposi's sarcoma herpesvirus (KSHV).
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Affiliation(s)
- Enrique A Mesri
- Viral Oncology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; AIDS Malignancies Scientific Working Group, Miami Center for AIDS Research, Department and Graduate Program in Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Mark A Feitelson
- Department of Biology, Temple University, Philadelphia, PA 19122, USA.
| | - Karl Munger
- Division of Infectious Diseases, Department of Medicine, Brigham and Women Hospital and Harvard Medical School, Boston, MA 02115, USA.
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Al-Salam S, Awwad A, Alashari M. Epstein-Barr virus infection is inversely correlated with the expression of retinoblastoma protein in Reed-Sternberg cells in classic Hodgkin lymphoma. Int J Clin Exp Pathol 2014; 7:7508-7517. [PMID: 25550786 PMCID: PMC4270594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Accepted: 11/08/2014] [Indexed: 06/04/2023]
Abstract
Classic Hodgkin lymphoma (cHL) is characterized by few neoplastic Hodgkin/Reed-Sternberg (H/RS) cells in a background of intense inflammatory infiltrate. Epstein-Barr virus (EBV) has been shown to affect cell cycle and regulation of apoptosis. In total, 82 cases of cHL were studied. Five- micrometer sections were prepared and stained with haematoxylin and eosin and immunohistochemical streptavidin-biotin methods for EBV-LMP-1, pRb, ki-67 and cleaved caspase-3. In-situ hybridization for EBV encoded RNA was used to confirm the detection of EBV in H/RS cells. There were 45 nodular sclerosis, 28 mixed cellularity, 4 lymphocyte-rich, and 5 lymphocyte depletion subtypes in this series of cases. EBV and pRb were detected in 55% (46/82) and 64% (50/82) of the cases respectively. EBV was detected in 78% (25/32) of pRb-negative cases and 81% (29/36) of EBV-negative cases are pRb-positive. A statistically significant inverse relationship was observed between the presence of EBV and expression of pRb (P = 0.001). In conclusion, EBV infection is inversely correlated with pRb in H/RS cells in cHL.
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Affiliation(s)
- Suhail Al-Salam
- Department of Pathology, College of Medicine and Health Sciences, United Arab Emirates UniversityAl Ain, United Arab Emirates
| | - Aktham Awwad
- Department of Laboratory Medicine, Tawam Hospital in Affiliation with Johns Hopkins International MedicineAl Ain, United Arab Emirates
| | - Mouied Alashari
- Department Of Pathology, University of Utah, Primary Children’s Hospital100 North Mario Capecchi Drive, Salt Lake City, UT 84103, USA
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Tursiella ML, Bowman ER, Wanzeck KC, Throm RE, Liao J, Zhu J, Sample CE. Epstein-Barr virus nuclear antigen 3A promotes cellular proliferation by repression of the cyclin-dependent kinase inhibitor p21WAF1/CIP1. PLoS Pathog 2014; 10:e1004415. [PMID: 25275486 PMCID: PMC4183747 DOI: 10.1371/journal.ppat.1004415] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Accepted: 08/21/2014] [Indexed: 11/20/2022] Open
Abstract
Latent infection by Epstein-Barr virus (EBV) is highly associated with the endemic form of Burkitt lymphoma (eBL), which typically limits expression of EBV proteins to EBNA-1 (Latency I). Interestingly, a subset of eBLs maintain a variant program of EBV latency - Wp-restricted latency (Wp-R) - that includes expression of the EBNA-3 proteins (3A, 3B and 3C), in addition to EBNA-1. In xenograft assays, Wp-R BL cell lines were notably more tumorigenic than their counterparts that maintain Latency I, suggesting that the additional latency-associated proteins expressed in Wp-R influence cell proliferation and/or survival. Here, we evaluated the contribution of EBNA-3A. Consistent with the enhanced tumorigenic potential of Wp-R BLs, knockdown of EBNA-3A expression resulted in abrupt cell-cycle arrest in G0/G1 that was concomitant with conversion of retinoblastoma protein (Rb) to its hypophosphorylated state, followed by a loss of Rb protein. Comparable results were seen in EBV-immortalized B lymphoblastoid cell lines (LCLs), consistent with the previous observation that EBNA-3A is essential for sustained growth of these cells. In agreement with the known ability of EBNA-3A and EBNA-3C to cooperatively repress p14ARF and p16INK4a expression, knockdown of EBNA-3A in LCLs resulted in rapid elevation of p14ARF and p16INK4a. By contrast, p16INK4a was not detectably expressed in Wp-R BL and the low-level expression of p14ARF was unchanged by EBNA-3A knockdown. Amongst other G1/S regulatory proteins, only p21WAF1/CIP1, a potent inducer of G1 arrest, was upregulated following knockdown of EBNA-3A in Wp-R BL Sal cells and LCLs, coincident with hypophosphorylation and destabilization of Rb and growth arrest. Furthermore, knockdown of p21WAF1/CIP1 expression in Wp-R BL correlated with an increase in cellular proliferation. This novel function of EBNA-3A is distinct from the functions previously described that are shared with EBNA-3C, and likely contributes to the proliferation of Wp-R BL cells and LCLs. Epstein-Barr virus (EBV) infects over 98% of the population worldwide and is associated with a variety of human cancers. In the healthy host, the virus represses expression of its proteins to avoid detection by the immune system to enable it to remain in the body for the lifetime of its host, a situation known as latency. This downregulation was first observed in EBV-associated Burkitt lymphoma (BL), which classically express only one viral protein, EBNA-1. A subset of BL named Wp-restricted (Wp-R) BL express additional latency-associated viral proteins. Because Wp-R BL also express wild-type p53 (which normally prevents cellular proliferation), we wanted to explore the possibility that these viral proteins play a role in tumorigenesis. Indeed, we have demonstrated that Wp-R BL cells are more tumorigenic in immunocompromised mice than other BL. Here, we have investigated the role of one of these viral proteins, EBNA-3A. If we inhibit the expression of EBNA-3A, Wp-R BL cells fail to proliferate and express increased p21WAF1/CIP1, a cellular protein that inhibits cell proliferation. These results suggest that this previously undescribed function of EBNA-3A plays a role in the proliferation and likely contributes to tumorigenesis in Wp-R BL.
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Affiliation(s)
- Melissa L. Tursiella
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, and the Penn State Hershey Cancer Institute, Hershey, Pennsylvania, United States of America
| | - Emily R. Bowman
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, and the Penn State Hershey Cancer Institute, Hershey, Pennsylvania, United States of America
| | - Keith C. Wanzeck
- Department of Biochemistry, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Robert E. Throm
- Department of Biochemistry, St. Jude Children's Research Hospital, Memphis, Tennessee, United States of America
| | - Jason Liao
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, and the Penn State Hershey Cancer Institute, Hershey, Pennsylvania, United States of America
| | - Junjia Zhu
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, and the Penn State Hershey Cancer Institute, Hershey, Pennsylvania, United States of America
| | - Clare E. Sample
- Department of Microbiology and Immunology, Pennsylvania State University College of Medicine, and the Penn State Hershey Cancer Institute, Hershey, Pennsylvania, United States of America
- * E-mail:
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Banerjee S, Lu J, Cai Q, Sun Z, Jha HC, Robertson ES. EBNA3C augments Pim-1 mediated phosphorylation and degradation of p21 to promote B-cell proliferation. PLoS Pathog 2014; 10:e1004304. [PMID: 25121590 PMCID: PMC4133388 DOI: 10.1371/journal.ppat.1004304] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 06/28/2014] [Indexed: 12/11/2022] Open
Abstract
Epstein–Barr virus (EBV), a ubiquitous human herpesvirus, can latently infect the human population. EBV is associated with several types of malignancies originating from lymphoid and epithelial cell types. EBV latent antigen 3C (EBNA3C) is essential for EBV-induced immortalization of B-cells. The Moloney murine leukemia provirus integration site (PIM-1), which encodes an oncogenic serine/threonine kinase, is linked to several cellular functions involving cell survival, proliferation, differentiation, and apoptosis. Notably, enhanced expression of Pim-1 kinase is associated with numerous hematological and non-hematological malignancies. A higher expression level of Pim-1 kinase is associated with EBV infection, suggesting a crucial role for Pim-1 in EBV-induced tumorigenesis. We now demonstrate a molecular mechanism which reveals a direct role for EBNA3C in enhancing Pim-1 expression in EBV-infected primary B-cells. We also showed that EBNA3C is physically associated with Pim-1 through its amino-terminal domain, and also forms a molecular complex in B-cells. EBNA3C can stabilize Pim-1 through abrogation of the proteasome/Ubiquitin pathway. Our results demonstrate that EBNA3C enhances Pim-1 mediated phosphorylation of p21 at the Thr145 residue. EBNA3C also facilitated the nuclear localization of Pim-1, and promoted EBV transformed cell proliferation by altering Pim-1 mediated regulation of the activity of the cell-cycle inhibitor p21/WAF1. Our study demonstrated that EBNA3C significantly induces Pim-1 mediated proteosomal degradation of p21. A significant reduction in cell proliferation of EBV-transformed LCLs was observed upon stable knockdown of Pim-1. This study describes a critical role for the oncoprotein Pim-1 in EBV-mediated oncogenesis, as well as provides novel insights into oncogenic kinase-targeted therapeutic intervention of EBV-associated cancers. The oncogenic serine/threonine kinase Pim-1 is upregulated in a number of human cancers including lymphomas, gastric, colorectal and prostate carcinomas. EBV nuclear antigen 3C (EBNA3C) is essential for EBV-induced transformation of human primary B-lymphocytes. Our current study revealed that EBNA3C significantly enhances Pim-1 kinase expression at both the transcript and protein levels. EBNA3C also interacts with Pim-1 and can form a complex in EBV-transformed cells. Moreover, EBNA3C increases nuclear localization of Pim-1 and stabilizes Pim-1 protein levels by inhibiting its poly-ubiquitination. Additionally, EBNA3C augments Pim-1 mediated phosphorylation of p21 and its proteosomal degradation. Stable knockdown of Pim-1 using si-RNA showed a significant decrease in proliferation of EBV transformed lymphoblastoid cell lines and subsequent induction of apoptosis by triggering the intrinsic apoptotic pathway. Therefore, our study demonstrated a new mechanism by which the oncogenic Pim-1 kinase targeted by EBV latent antigen 3C can inhibit p21 function, and is therefore a potential therapeutic target for the treatment of EBV-associated malignancies.
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Affiliation(s)
- Shuvomoy Banerjee
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Jie Lu
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Qiliang Cai
- Key Laboratory of Molecular Medical Virology (Ministries of Education and Health), School of Basic Medical Sciences, Shanghai Medical College, Fudan University, Shanghai, People's Republic of China
| | - Zhiguo Sun
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hem Chandra Jha
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Erle S. Robertson
- Department of Microbiology and the Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Bazot Q, Deschamps T, Tafforeau L, Siouda M, Leblanc P, Harth-Hertle ML, Rabourdin-Combe C, Lotteau V, Kempkes B, Tommasino M, Gruffat H, Manet E. Epstein-Barr virus nuclear antigen 3A protein regulates CDKN2B transcription via interaction with MIZ-1. Nucleic Acids Res 2014; 42:9700-16. [PMID: 25092922 PMCID: PMC4150796 DOI: 10.1093/nar/gku697] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The Epstein-Barr virus (EBV) nuclear antigen 3 family of protein is critical for the EBV-induced primary B-cell growth transformation process. Using a yeast two-hybrid screen we identified 22 novel cellular partners of the EBNA3s. Most importantly, among the newly identified partners, five are known to play direct and important roles in transcriptional regulation. Of these, the Myc-interacting zinc finger protein-1 (MIZ-1) is a transcription factor initially characterized as a binding partner of MYC. MIZ-1 activates the transcription of a number of target genes including the cell cycle inhibitor CDKN2B. Focusing on the EBNA3A/MIZ-1 interaction we demonstrate that binding occurs in EBV-infected cells expressing both proteins at endogenous physiological levels and that in the presence of EBNA3A, a significant fraction of MIZ-1 translocates from the cytoplasm to the nucleus. Moreover, we show that a trimeric complex composed of a MIZ-1 recognition DNA element, MIZ-1 and EBNA3A can be formed, and that interaction of MIZ-1 with nucleophosmin (NPM), one of its coactivator, is prevented by EBNA3A. Finally, we show that, in the presence of EBNA3A, expression of the MIZ-1 target gene, CDKN2B, is downregulated and repressive H3K27 marks are established on its promoter region suggesting that EBNA3A directly counteracts the growth inhibitory action of MIZ-1.
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Affiliation(s)
- Quentin Bazot
- CIRI, International Center for Infectiology Research, Oncogenic Herpesviruses team, Université de Lyon, Lyon 69364, France Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France
| | - Thibaut Deschamps
- CIRI, International Center for Infectiology Research, Oncogenic Herpesviruses team, Université de Lyon, Lyon 69364, France Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France
| | - Lionel Tafforeau
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France Ecole Normale Supérieure de Lyon, Lyon 69364, France
| | - Maha Siouda
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Pascal Leblanc
- CNRS, UMR5308, Lyon 69364, France CNRS UMR5239, Laboratoire de Biologie de la Cellule, Lyon 69364, France
| | - Marie L Harth-Hertle
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Chantal Rabourdin-Combe
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France Ecole Normale Supérieure de Lyon, Lyon 69364, France
| | - Vincent Lotteau
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France Ecole Normale Supérieure de Lyon, Lyon 69364, France
| | - Bettina Kempkes
- Department of Gene Vectors, Helmholtz Center Munich, German Research Center for Environmental Health, Munich, Germany
| | - Massimo Tommasino
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Henri Gruffat
- CIRI, International Center for Infectiology Research, Oncogenic Herpesviruses team, Université de Lyon, Lyon 69364, France Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France
| | - Evelyne Manet
- CIRI, International Center for Infectiology Research, Oncogenic Herpesviruses team, Université de Lyon, Lyon 69364, France Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69364, France CIRI, International Center for Infectiology Research, Cell Biology of Viral Infections team, Université de Lyon, Lyon 69364, France INSERM, U1111, Lyon 69364, France CNRS, UMR5308, Lyon 69364, France
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Kwun HJ, Shuda M, Feng H, Camacho CJ, Moore PS, Chang Y. Merkel cell polyomavirus small T antigen controls viral replication and oncoprotein expression by targeting the cellular ubiquitin ligase SCFFbw7. Cell Host Microbe 2014; 14:125-35. [PMID: 23954152 DOI: 10.1016/j.chom.2013.06.008] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 05/09/2013] [Accepted: 06/10/2013] [Indexed: 10/26/2022]
Abstract
Merkel cell polyomavirus (MCV) causes an aggressive human skin cancer, Merkel cell carcinoma, through expression of small T (sT) and large T (LT) viral oncoproteins. MCV sT is also required for efficient MCV DNA replication by the multifunctional MCV LT helicase protein. We find that LT is targeted for proteasomal degradation by the cellular SCF(Fbw7) E3 ligase, which can be inhibited by sT through its LT-stabilization domain (LSD). Consequently, sT also stabilizes cellular SCF(Fbw7) targets, including the cell-cycle regulators c-Myc and cyclin E. Mutating the sT LSD decreases LT protein levels and eliminates synergism in MCV DNA replication as well as sT-induced cell transformation. SCF(Fbw7) knockdown mimics sT-mediated stabilization of LT, but this knockdown is insufficient to fully reconstitute the transforming activity of a mutant LSD sT protein. Thus, MCV has evolved a regulatory system involving SCF(Fbw7) that controls viral replication but also contributes to host cell transformation.
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Affiliation(s)
- Hyun Jin Kwun
- Cancer Virology Program, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Affiliation(s)
- Xianting Ding
- Med‐X Research InstituteSchool of Biomedical EngineeringShanghai Jiao Tong UniversityShanghaiPeople's Republic of China
| | - Ningxia Liu
- Institute of Robotics & Automatic Information SystemNankai UniversityTianjinPeople's Republic of China
| | - Kyle Matsuo
- Bioengineering DepartmentUniversity of CaliforniaLos AngelesUSA
| | - Mingzhu Sun
- Institute of Robotics & Automatic Information SystemNankai UniversityTianjinPeople's Republic of China
| | - Xin Zhao
- Institute of Robotics & Automatic Information SystemNankai UniversityTianjinPeople's Republic of China
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Abstract
Nasopharyngeal carcinoma (NPC) is a highly invasive cancer with poor prognosis. One of the recurring themes of NPC biology and treatments is DNA damage. Epstein-Barr virus infection, which is generally accepted as a key etiological factor for NPC, triggers DNA damage responses. In normal cells, DNA damage checkpoints are able to prevent cell cycle progression following DNA damage and are critical for maintaining genome stability. Main features of the checkpoints include activation of ATM and ATR by sensors of DNA damage, which activates effector kinases CHK1 and CHK2; they in turn targets the CDC25/WEE1-cyclin B1-CDK1 axis to cause G(2) arrest, or the p53-p21(CIP1/WAF1) and pRb pathways to cause G(1) arrest. Significantly, these checkpoints are typically disrupted in NPC cells. While mutations are relatively rare, mechanisms including promoter modifications, miRNAs, and actions of Epstein-Barr virus-encoded proteins such as EBNA3C and LMP1 have been described. Paradoxically, radiation-mediated DNA damage remains the primary treatment of NPC. How dysregulation of the DNA damage checkpoints contribute to NPC tumorigenesis and responses to treatment remain poorly understood. In this review, the current understanding of the molecular mechanisms of the various DNA damage checkpoints and what is known about them in NPC are discussed.
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Affiliation(s)
- Randy Y C Poon
- Division of Life Science, Center for Cancer Research, and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
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