1
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Singh AK, Yadav D, Malviya R. Splicing DNA Damage Adaptations for the Management of Cancer Cells. Curr Gene Ther 2024; 24:135-146. [PMID: 38282448 DOI: 10.2174/0115665232258528231018113410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 08/07/2023] [Accepted: 09/25/2023] [Indexed: 01/30/2024]
Abstract
Maintaining a tumour cell's resistance to apoptosis (organized cell death) is essential for cancer to metastasize. Signal molecules play a critical function in the tightly regulated apoptotic process. Apoptosis may be triggered by a wide variety of cellular stresses, including DNA damage, but its ultimate goal is always the same: the removal of damaged cells that might otherwise develop into tumours. Many chemotherapy drugs rely on cancer cells being able to undergo apoptosis as a means of killing them. The mechanisms by which DNA-damaging agents trigger apoptosis, the interplay between pro- and apoptosis-inducing signals, and the potential for alteration of these pathways in cancer are the primary topics of this review.
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Affiliation(s)
- Arun Kumar Singh
- Department of Pharmacy, School of Medical and Allied Sciences, Galgotias University, Greater Noida, Uttar Pradesh, India
| | - Deepika Yadav
- Department of Pharmacy, School of Medical and Allied Sciences, Galgotias University, Greater Noida, Uttar Pradesh, India
| | - Rishabha Malviya
- Department of Pharmacy, School of Medical and Allied Sciences, Galgotias University, Greater Noida, Uttar Pradesh, India
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2
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Moore LN, Holmes DL, Sharma A, Landazuri Vinueza J, Lagunoff M. Bcl-xL is required to protect endothelial cells latently infected with KSHV from virus induced intrinsic apoptosis. PLoS Pathog 2023; 19:e1011385. [PMID: 37163552 PMCID: PMC10202281 DOI: 10.1371/journal.ppat.1011385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 05/22/2023] [Accepted: 04/24/2023] [Indexed: 05/12/2023] Open
Abstract
Kaposi's Sarcoma herpesvirus (KSHV) is the etiologic agent of Kaposi's Sarcoma (KS), a highly vascularized tumor common in AIDS patients and many countries in Africa. KSHV is predominantly in the latent state in the main KS tumor cell, the spindle cell, a cell expressing endothelial cell markers. To identify host genes important for KSHV latent infection of endothelial cells we previously used a global CRISPR/Cas9 screen to identify genes necessary for the survival or proliferation of latently infected cells. In this study we rescreened top hits and found that the highest scoring gene necessary for infected cell survival is the anti-apoptotic Bcl-2 family member Bcl-xL. Knockout of Bcl-xL or treatment with a Bcl-xL inhibitor leads to high levels of cell death in latently infected endothelial cells but not their mock counterparts. Cell death occurs through apoptosis as shown by increased PARP cleavage and activation of caspase-3/7. Knockout of the pro-apoptotic protein, Bax, eliminates the requirement for Bcl-xL. Interestingly, neither Bcl-2 nor Mcl-1, related and often redundant anti-apoptotic proteins of the Bcl-2 protein family, are necessary for the survival of latently infected endothelial cells, likely due to their lack of expression in all the endothelial cell types we have examined. Bcl-xL is not required for the survival of latently infected primary effusion lymphoma (PEL) cells or other cell types tested. Expression of the KSHV major latent locus alone in the absence of KSHV infection led to sensitivity to the absence of Bcl-xL, indicating that viral gene expression from the latent locus induces intrinsic apoptosis leading to the requirement for Bcl-xL in endothelial cells. The critical requirement of Bcl-xL during KSHV latency makes it an intriguing therapeutic target for KS tumors.
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Affiliation(s)
- Lyndsey N. Moore
- University of Washington Department of Microbiology, Seattle, Washington, United States of America
| | - Daniel L. Holmes
- University of Washington Department of Microbiology, Seattle, Washington, United States of America
| | - Anjali Sharma
- University of Washington Department of Microbiology, Seattle, Washington, United States of America
| | | | - Michael Lagunoff
- University of Washington Department of Microbiology, Seattle, Washington, United States of America
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3
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Gupta J, Abdulsahib WK, Turki Jalil A, Saadi Kareem D, Aminov Z, Alsaikhan F, Ramírez-Coronel AA, Ramaiah P, Farhood B. Prostate Cancer and microRNAs: New insights into Apoptosis. Pathol Res Pract 2023; 245:154436. [PMID: 37062208 DOI: 10.1016/j.prp.2023.154436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/30/2023] [Accepted: 04/02/2023] [Indexed: 04/09/2023]
Abstract
Prostate cancer (PCa) is known as one of the most prevalent malignancies globally and is not yet curable owing to its progressive nature. It has been well documented that Genetic and epigenetic alterations maintain mandatory roles in PCa development. Apoptosis, a form of programmed cell death, has been shown to be involved in a number of physiological processes. Apoptosis disruption is considered as one of the main mechanism involved in lots of pathological conditions, especially malignancy. There is ample of evidence in support of the fact that microRNAs (miRNAs) have crucial roles in several cellular biological processes, including apoptosis. Escaping from apoptosis is a common event in malignancy progression. Emerging evidence revealed miRNAs capabilities to act as apoptotic or anti-apoptotic factors by altering the expression levels of tumor inhibitor or oncogene genes. In the present narrative review, we described in detail how apoptosis dysfunction could be involved in PCa processes and additionally, the mechanisms behind miRNAs affect the apoptosis pathways in PCa. Identifying the mechanisms behind the effects of miRNAs and their targets on apoptosis can provide scientists new targets for PCa treatment.
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Affiliation(s)
- Jitendra Gupta
- Institute of Pharmaceutical Research, GLA University, Mathura 281406, U. P., India
| | - Waleed K Abdulsahib
- Department of Pharmacology and Toxicology, College of Pharmacy, Al Farahidi University, Baghdad, Iraq
| | - Abduladheem Turki Jalil
- Medical Laboratories Techniques Department, Al-Mustaqbal University College, Babylon, Hilla, 51001, Iraq.
| | | | - Zafar Aminov
- Department of Public Health and Healthcare management, Samarkand State Medical University, 18 Amir Temur Street, Samarkand, Uzbekistan; Department of Scientific Affairs, Tashkent State Dental Institute, 103 Makhtumkuli Str., Tashkent, Uzbekistan
| | - Fahad Alsaikhan
- College of Pharmacy, Prince Sattam Bin Abdulaziz University, Alkharj, Saudi Arabia.
| | - Andrés Alexis Ramírez-Coronel
- Azogues Campus Nursing Career, Health and Behavior Research Group (HBR), Psychometry and Ethology Laboratory, Catholic University of Cuenca, Ecuador; Epidemiology and Biostatistics Research Group, CES University, Colombia; Educational Statistics Research Group (GIEE), National University of Education, Ecuador
| | | | - Bagher Farhood
- Department of Medical Physics and Radiology, Faculty of Paramedical Sciences, Kashan University of Medical Sciences, Kashan, Iran.
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4
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Mohanty S, Kumar A, Das P, Sahu SK, Mukherjee R, Ramachandranpillai R, Nair SS, Choudhuri T. Nm23-H1 induces apoptosis in primary effusion lymphoma cells via inhibition of NF-κB signaling through interaction with oncogenic latent protein vFLIP K13 of Kaposi’s sarcoma-associated herpes virus. Cell Oncol (Dordr) 2022; 45:967-989. [DOI: 10.1007/s13402-022-00701-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2022] [Indexed: 11/03/2022] Open
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5
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Tuomela K, Ambrose AR, Davis DM. Escaping Death: How Cancer Cells and Infected Cells Resist Cell-Mediated Cytotoxicity. Front Immunol 2022; 13:867098. [PMID: 35401556 PMCID: PMC8984481 DOI: 10.3389/fimmu.2022.867098] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/04/2022] [Indexed: 12/14/2022] Open
Abstract
Cytotoxic lymphocytes are critical in our immune defence against cancer and infection. Cytotoxic T lymphocytes and Natural Killer cells can directly lyse malignant or infected cells in at least two ways: granule-mediated cytotoxicity, involving perforin and granzyme B, or death receptor-mediated cytotoxicity, involving the death receptor ligands, tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) and Fas ligand (FasL). In either case, a multi-step pathway is triggered to facilitate lysis, relying on active pro-death processes and signalling within the target cell. Because of this reliance on an active response from the target cell, each mechanism of cell-mediated killing can be manipulated by malignant and infected cells to evade cytolytic death. Here, we review the mechanisms of cell-mediated cytotoxicity and examine how cells may evade these cytolytic processes. This includes resistance to perforin through degradation or reduced pore formation, resistance to granzyme B through inhibition or autophagy, and resistance to death receptors through inhibition of downstream signalling or changes in protein expression. We also consider the importance of tumour necrosis factor (TNF)-induced cytotoxicity and resistance mechanisms against this pathway. Altogether, it is clear that target cells are not passive bystanders to cell-mediated cytotoxicity and resistance mechanisms can significantly constrain immune cell-mediated killing. Understanding these processes of immune evasion may lead to novel ideas for medical intervention.
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Affiliation(s)
- Karoliina Tuomela
- The Lydia Becker Institute of Immunology and Inflammation, The University of Manchester, Manchester, United Kingdom
| | - Ashley R Ambrose
- The Lydia Becker Institute of Immunology and Inflammation, The University of Manchester, Manchester, United Kingdom
| | - Daniel M Davis
- The Lydia Becker Institute of Immunology and Inflammation, The University of Manchester, Manchester, United Kingdom
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6
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Primary Effusion Lymphoma: A Clinicopathologic Perspective. Cancers (Basel) 2022; 14:cancers14030722. [PMID: 35158997 PMCID: PMC8833393 DOI: 10.3390/cancers14030722] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/03/2021] [Accepted: 12/22/2021] [Indexed: 02/06/2023] Open
Abstract
Primary effusion lymphoma (PEL) is a rare, aggressive B-cell lymphoma that usually localizes to serous body cavities to subsequently form effusions in the absence of a discrete mass. Although some tumors can develop in extracavitary locations, the areas most often affected include the peritoneum, pleural space, and the pericardium. PEL is associated with the presence of human herpesvirus 8 (HHV8), also called the Kaposi sarcoma-associated herpesvirus (KSHV), with some variability in transformation potential suggested by frequent coinfection with the Epstein-Barr virus (EBV) (~80%), although the nature of the oncogenesis is unclear. Most patients suffering with this disease are to some degree immunocompromised (e.g., Human immunodeficiency virus (HIV) infection or post-solid organ transplantation) and, even with aggressive treatment, prognosis remains poor. There is no definitive guideline for the treatment of PEL, although CHOP-like regimens (cyclophosphamide, doxorubicin, vincristine, and prednisone) are frequently prescribed and, given the rarity of this disease, therapeutic focus is being redirected to personalized and targeted approaches in the experimental realm. Current clinical trials include the combination of lenalidomide and rituximab into the EPOCH regimen and the treatment of individuals with relapsed/refractory EBV-associated disease with tabelecleucel.
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7
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Silva DMD, Gonçales JP, Silva Júnior JVJ, Lopes TRR, Bezerra LA, Barros de Lorena VM, Duarte Coêlho MRC. Evaluation of IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ cytokines in HIV/HHV-8 coinfection. J Med Virol 2021; 93:4033-4037. [PMID: 32926412 DOI: 10.1002/jmv.26516] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 09/02/2020] [Accepted: 09/08/2020] [Indexed: 11/11/2022]
Abstract
Imbalance in the immune response is one of the main pathogenic mechanisms of diseases related with human immunodeficiency virus (HIV)/human gammaherpesvirus 8 (HHV-8) coinfection, such as Kaposi's sarcoma (KS), primary effusion lymphoma (PEL), multicentric Castleman disease (MCD) and the Kaposi's sarcoma-associated herpesvirus inflammatory cytokine syndrome (KICS). However, significant changes in pro- and anti-inflammatory cytokine levels may be observed in HIV/HHV-8 individuals who are negative for KS, PEL, MCD, and/or KICS. In this study, serum levels of interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor nucrosis factor α (TNF-α) and interferon γ (IFN-γ) were assessed in 69 HIV and 48 HIV/HHV-8 individuals, all negatives for HHV-8-related diseases. The cytokines were measured by flow cytometry and analyzed by the Mann-Whitney test. The p < .05 and 95% confidence interval were considered in all analyzes. IL-4 (p = .0155), IL-6 (p = .0036), and IL-10 (p = .0036) levels were significantly higher in HIV/HHV-8 patients than in the HIV group. On the other hand, IL-2 (p = .2295), TNF-α (p = .1216) and IFN-γ (p = .1178) did not differ between the groups analyzed. To our knowledge, to date, this is the first report on significant differences in the levels of IL-4 and IL-6 in HIV versus HIV/HHV-8 individuals. Finally, these early findings are important as a prognostic tool and contribute to clarifying the HHV-8-host interaction.
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Affiliation(s)
- Dayvson Maurício da Silva
- Virology Sector, Laboratory of Immunopathology Keizo Asami, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - Juliana Prado Gonçales
- Virology Sector, Laboratory of Immunopathology Keizo Asami, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | - José Valter Joaquim Silva Júnior
- Virology Sector, Laboratory of Immunopathology Keizo Asami, Federal University of Pernambuco, Recife, Pernambuco, Brazil
- Virology Sector, Department of Preventive Veterinary Medicine, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
- Department of Microbiology and Parasitology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Thaísa Regina Rocha Lopes
- Virology Sector, Laboratory of Immunopathology Keizo Asami, Federal University of Pernambuco, Recife, Pernambuco, Brazil
- Virology Sector, Department of Preventive Veterinary Medicine, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Luan Araújo Bezerra
- Virology Sector, Laboratory of Immunopathology Keizo Asami, Federal University of Pernambuco, Recife, Pernambuco, Brazil
| | | | - Maria Rosângela Cunha Duarte Coêlho
- Virology Sector, Laboratory of Immunopathology Keizo Asami, Federal University of Pernambuco, Recife, Pernambuco, Brazil
- Department of Physiology and Pharmacology, Federal University of Pernambuco, Recife, Pernambuco, Brazil
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8
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Choi YB, Cousins E, Nicholas J. Novel Functions and Virus-Host Interactions Implicated in Pathogenesis and Replication of Human Herpesvirus 8. Recent Results Cancer Res 2021; 217:245-301. [PMID: 33200369 DOI: 10.1007/978-3-030-57362-1_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Human herpesvirus 8 (HHV-8) is classified as a γ2-herpesvirus and is related to Epstein-Barr virus (EBV), a γ1-herpesvirus. One important aspect of the γ-herpesviruses is their association with neoplasia, either naturally or in animal model systems. HHV-8 is associated with B-cell-derived primary effusion lymphoma (PEL) and multicentric Castleman's disease (MCD), endothelial-derived Kaposi's sarcoma (KS), and KSHV inflammatory cytokine syndrome (KICS). EBV is also associated with a number of B-cell malignancies, such as Burkitt's lymphoma, Hodgkin's lymphoma, and posttransplant lymphoproliferative disease, in addition to epithelial nasopharyngeal and gastric carcinomas. Despite the similarities between these viruses and their associated malignancies, the particular protein functions and activities involved in key aspects of virus biology and neoplastic transformation appear to be quite distinct. Indeed, HHV-8 specifies a number of proteins for which counterparts had not previously been identified in EBV, other herpesviruses, or even viruses in general, and these proteins are believed to play vital functions in virus biology and to be involved centrally in viral pathogenesis. Additionally, a set of microRNAs encoded by HHV-8 appears to modulate the expression of multiple host proteins to provide conditions conductive to virus persistence within the host and possibly contributing to HHV-8-induced neoplasia. Here, we review the molecular biology underlying these novel virus-host interactions and their potential roles in both virus biology and virus-associated disease.
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Affiliation(s)
- Young Bong Choi
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Department of Oncology, Johns Hopkins University School of Medicine, 1650 Orleans Street, Baltimore, MD, 21287, USA.
| | - Emily Cousins
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Department of Oncology, Johns Hopkins University School of Medicine, 1650 Orleans Street, Baltimore, MD, 21287, USA
| | - John Nicholas
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Department of Oncology, Johns Hopkins University School of Medicine, 1650 Orleans Street, Baltimore, MD, 21287, USA
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9
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Konikov-Rozenman J, Breuer R, Kaminski N, Wallach-Dayan SB. CMH-Small Molecule Docks into SIRT1, Elicits Human IPF-Lung Fibroblast Cell Death, Inhibits Ku70-deacetylation, FLIP and Experimental Pulmonary Fibrosis. Biomolecules 2020; 10:biom10070997. [PMID: 32630842 PMCID: PMC7408087 DOI: 10.3390/biom10070997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/25/2020] [Accepted: 06/27/2020] [Indexed: 02/07/2023] Open
Abstract
Regenerative capacity in vital organs is limited by fibrosis propensity. Idiopathic pulmonary fibrosis (IPF), a progressive lung disease linked with aging, is a classic example. In this study, we show that in flow cytometry, immunoblots (IB) and in lung sections, FLIP levels can be regulated, in vivo and in vitro, through SIRT1 activity inhibition by CMH (4-(4-Chloro-2-methylphenoxy)-N-hydroxybutanamide), a small molecule that, as we determined here by structural biology calculations, docked into its nonhistone substrate Ku70-binding site. Ku70 immunoprecipitations and immunoblots confirmed our theory that Ku70-deacetylation, Ku70/FLIP complex, myofibroblast resistance to apoptosis, cell survival, and lung fibrosis in bleomycin-treated mice, are reduced and regulated by CMH. Thus, small molecules associated with SIRT1-mediated regulation of Ku70 deacetylation, affecting FLIP stabilization in fibrotic-lung myofibroblasts, may be a useful strategy, enabling tissue regeneration.
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Affiliation(s)
- Jenya Konikov-Rozenman
- Lung Cellular and Molecular Biology Laboratory, Institute of Pulmonary Medicine, Hadassah–Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel; (J.K.-R.); (R.B.)
| | - Raphael Breuer
- Lung Cellular and Molecular Biology Laboratory, Institute of Pulmonary Medicine, Hadassah–Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel; (J.K.-R.); (R.B.)
- Department of Pathology and Laboratory Medicine, 670 Albany St, 4th Floor, Boston University School of Medicine, Boston, MA 02118, USA
| | - Naftali Kaminski
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, POB 208057, 300 Cedar Street TAC-441 South, New Haven, CT 06520-8057, USA;
| | - Shulamit B. Wallach-Dayan
- Lung Cellular and Molecular Biology Laboratory, Institute of Pulmonary Medicine, Hadassah–Hebrew University Medical Center, POB 12000, Jerusalem 91120, Israel; (J.K.-R.); (R.B.)
- Correspondence: ; Tel.: +972-2-6776622
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10
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Smyth P, Sessler T, Scott CJ, Longley DB. FLIP(L): the pseudo-caspase. FEBS J 2020; 287:4246-4260. [PMID: 32096279 PMCID: PMC7586951 DOI: 10.1111/febs.15260] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 02/10/2020] [Accepted: 02/24/2020] [Indexed: 12/27/2022]
Abstract
Possessing structural homology with their active enzyme counterparts but lacking catalytic activity, pseudoenzymes have been identified for all major enzyme groups. Caspases are a family of cysteine‐dependent aspartate‐directed proteases that play essential roles in regulating cell death and inflammation. Here, we discuss the only human pseudo‐caspase, FLIP(L), a paralog of the apoptosis‐initiating caspases, caspase‐8 and caspase‐10. FLIP(L) has been shown to play a key role in regulating the processing and activity of caspase‐8, thereby modulating apoptotic signaling mediated by death receptors (such as TRAIL‐R1/R2), TNF receptor‐1 (TNFR1), and Toll‐like receptors. In this review, these canonical roles of FLIP(L) are discussed. Additionally, a range of nonclassical pseudoenzyme roles are described, in which FLIP(L) functions independently of caspase‐8. These nonclassical pseudoenzyme functions enable FLIP(L) to play key roles in the regulation of a wide range of biological processes beyond its canonical roles as a modulator of cell death.
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Affiliation(s)
- Peter Smyth
- The Patrick G Johnston Centre for Cancer Research, Queen's University, Belfast, UK
| | - Tamas Sessler
- The Patrick G Johnston Centre for Cancer Research, Queen's University, Belfast, UK
| | - Christopher J Scott
- The Patrick G Johnston Centre for Cancer Research, Queen's University, Belfast, UK
| | - Daniel B Longley
- The Patrick G Johnston Centre for Cancer Research, Queen's University, Belfast, UK
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11
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Angius F, Ingianni A, Pompei R. Human Herpesvirus 8 and Host-Cell Interaction: Long-Lasting Physiological Modifications, Inflammation and Related Chronic Diseases. Microorganisms 2020; 8:E388. [PMID: 32168836 PMCID: PMC7143610 DOI: 10.3390/microorganisms8030388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/07/2020] [Accepted: 03/09/2020] [Indexed: 01/13/2023] Open
Abstract
Oncogenic and latent-persistent viruses belonging to both DNA and RNA groups are known to cause serious metabolism alterations. Among these, the Human Herpesvirus 8 (HHV8) infection induces stable modifications in biochemistry and cellular metabolism, which in turn affect its own pathological properties. HHV8 enhances the expression of insulin receptors, supports the accumulation of neutral lipids in cytoplasmic lipid droplets and induces alterations in both triglycerides and cholesterol metabolism in endothelial cells. In addition, HHV8 is also known to modify immune response and cytokine production with implications for cell oxidative status (i.e., reactive oxygen species activation). This review underlines the recent findings regarding the role of latent and persistent HHV8 viral infection in host physiology and pathogenesis.
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12
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Greene S, Patel P, Allen CT. How patients with an intact immune system develop head and neck cancer. Oral Oncol 2019; 92:26-32. [PMID: 31010619 DOI: 10.1016/j.oraloncology.2019.03.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/28/2019] [Accepted: 03/13/2019] [Indexed: 12/18/2022]
Abstract
Although the adaptive immune system can detect and eliminate malignant cells, patients with intact and fully functional immune systems develop head and neck cancer. How is this paradox explained? Manuscripts published in the English language from 1975 to 2018 were reviewed using search inputs related to tumor cell antigenicity and immunogenicity, immunodominance, cancer immunoediting and genomic alterations present within carcinomas. Early in tumor development, T cell responses to immunodominant antigens may lead to the elimination of cancer cells expressing these antigens and a tumor composed to tumor cells expressing only immunorecessive antigens. Conversely, other tumor cells may acquire genomic or epigenetic alterations that result in an antigen processing or presentation defect or other inability to be detected or killed by T cells. Such T cell insensitive tumor cells may also be selected for in a progressing tumor. Tumors harboring subpopulations of cells that cannot be eliminated by T cells may require non-T cell-based treatments, such as NK cell immunotherapies. Recognition of such tumor cell populations within a heterogeneous cancer may inform the selection of treatment for HNSCC in the future.
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Affiliation(s)
- Sarah Greene
- Translational Tumor Immunology Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
| | - Priya Patel
- Translational Tumor Immunology Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States
| | - Clint T Allen
- Translational Tumor Immunology Program, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, United States.
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13
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Latent infection with Kaposi's sarcoma-associated herpesvirus enhances retrotransposition of long interspersed element-1. Oncogene 2019; 38:4340-4351. [PMID: 30770900 DOI: 10.1038/s41388-019-0726-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 01/18/2019] [Indexed: 12/14/2022]
Abstract
Kaposi's sarcoma (KS)-associated herpesvirus (KSHV), a gamma-2 herpesvirus, is the causative agent of KS, primary effusion lymphoma (PEL), and a plasma cell variant of multicentric Castleman's disease. Although KSHV latency is detected in KS-related tumors, oncogenic pathways activated by KSHV latent infection are not fully understood. Here, we found that retrotransposition of long interspersed element-1 (L1), a retrotransposon in the human genome, was enhanced in PEL cells. Among the KSHV latent genes, viral FLICE-inhibitory protein (vFLIP) enhanced L1 retrotransposition in an NF-κB-dependent manner. Intracellular cell adhesion molecule-1 (ICAM-1), an NF-κB target, regulated the vFLIP-mediated enhancement of L1 retrotransposition. Furthermore, ICAM-1 downregulated the expression of Moloney leukemia virus 10 (MOV10), an L1 restriction factor. Knockdown of ICAM-1 or overexpression of MOV10 relieved the vFLIP-mediated enhancement of L1 retrotransposition. Collectively, during KSHV latency, vFLIP upregulates ICAM-1 in an NF-κB-dependent manner, which, in turn, downregulates MOV10 expression and thereby enhances L1 retrotransposition. Because active L1 retrotransposition can lead to genomic instability, which is commonly found in KS and PEL, activation of L1 retrotransposition during KSHV latency may accelerate oncogenic processes through enhancing genomic instability. Our results suggest that L1 retrotransposition may be a novel target for impeding tumor development in KSHV-infected patients.
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14
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Bibert S, Wójtowicz A, Taffé P, Tarr PE, Bernasconi E, Furrer H, Günthard HF, Hoffmann M, Kaiser L, Osthoff M, Fellay J, Cavassini M, Bochud PY. Interferon lambda 3/4 polymorphisms are associated with AIDS-related Kaposi's sarcoma. AIDS 2018; 32:2759-2765. [PMID: 30234607 DOI: 10.1097/qad.0000000000002004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Kaposi's sarcoma, the most common AIDS-related cancer, represents a major public concern in resource-limited countries. Single nucleotide polymorphisms within the Interferon lambda 3/4 region (IFNL3/4) determine the expression, function of IFNL4, and influence the clinical course of an increasing number of viral infections. OBJECTIVES To analyze whether IFNL3/4 variants are associated with susceptibility to AIDS-related Kaposi's sarcoma among MSM enrolled in the Swiss HIV Cohort Study (SHCS). METHODS The risk of developing Kaposi's sarcoma according to the carriage of IFNL3/4 SNPs rs8099917 and rs12980275 and their haplotypic combinations was assessed by using cumulative incidence curves and Cox regression models, accounting for relevant covariables. RESULTS Kaposi's sarcoma was diagnosed in 221 of 2558 MSM Caucasian SHCS participants. Both rs12980275 and rs8099917 were associated with an increased risk of Kaposi's sarcoma (cumulative incidence 15 versus 10%, P = 0.01 and 16 versus 10%, P = 0.009, respectively). Diplotypes predicted to produce the active P70 form (cumulative incidence 16 versus 10%, P = 0.01) but not the less active S70 (cumulative incidence 11 versus 10%, P = 0.7) form of IFNL4 were associated with an increased risk of Kaposi's sarcoma, compared with those predicted not to produce IFNL4. The associations remained significant in a multivariate Cox regression model after adjustment for age at infection, combination antiretroviral therapy, median CD4+ T-cell count nadir and CD4+ slopes (hazard ratio 1.42, 95% confidence interval 1.06-1.89, P = 0.02 for IFLN P70 versus no IFNL4). CONCLUSION This study reports for the first time an association between IFNL3/4 polymorphisms and susceptibility to AIDS-related Kaposi's sarcoma.
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Affiliation(s)
| | | | - Patrick Taffé
- Institute for Social and Preventive Medicine, University (IUMSP), Lausanne University Hospital, Lausanne
| | - Philip E Tarr
- Department of Medicine, Kantonspital Baselland, University of Basel, Bruderholz
| | - Enos Bernasconi
- Division of Infectious diseases, Regional hospital of Lugano, Lugano
| | - Hansjakob Furrer
- Department of Infectious Diseases, Bern University Hospital, University of Bern, Bern
| | - Huldrych F Günthard
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich
- Institute of Medical Virology, University of Zurich, Zurich
| | - Matthias Hoffmann
- Division of Infectious Diseases and Hospital Epidemiology, Department of Internal Medicine, Cantonal Hospital St. Gallen, St. Gallen
| | - Laurent Kaiser
- Laboratory of Virology, Division of Infectious Diseases and Division of Laboratory Medicine, University Hospital of Geneva and Medical School, University of Geneva, Geneva
| | - Michael Osthoff
- Division of Infectious Diseases and Hospital Epidemiology and Department of Internal Medicine, University Hospital Basel, Basel
| | - Jacques Fellay
- Global Health Institute, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne
- Precision Medicine unit, Lausanne University Hospital, Lausanne, Switzerland
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15
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Yang Z, Honda T, Ueda K. vFLIP upregulates IKKε, leading to spindle morphology formation through RelA activation. Virology 2018; 522:106-121. [PMID: 30029010 DOI: 10.1016/j.virol.2018.07.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 07/07/2018] [Accepted: 07/07/2018] [Indexed: 12/31/2022]
Abstract
Kaposi's sarcoma (KS)-associated herpesvirus (KSHV) vFLIP, a latent gene of KSHV, was first identified as a FLICE-inhibitory protein (FLIP) protecting cells from apoptosis. The vFLIP protein has been shown to activate the NF-κB signaling involved in spindle morphology formation both in HUVECs infected with KSHV and Kaposi's sarcoma (KS) itself. In this study, we independently established stably vFLIP-expressing cells and showed that they exhibited upregulated NF-κB family protein expression independent of the ability of IKKs to bind vFLIP. Further, vFLIP induced upregulation of IKKε, phosphorylation of RelA at Ser468 (p-RelA S468) and nuclear localization of Re1A concomitant with spindle morphology formation, and these effects were reversed by knockdown of IKKε and treatment with Bay-11. Overexpression of IKKε alone also showed spindle morphology formation with p-RelA S468. In conclusion, the spindle cell morphology in KS should be induced by RelA activation (p-RelA S468) by IKKε upregulation in vFLIP-expressing EA hy926 cells.
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Affiliation(s)
- Zunlin Yang
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Tomoyuki Honda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Keiji Ueda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
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16
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Humphreys L, Espona-Fiedler M, Longley DB. FLIP as a therapeutic target in cancer. FEBS J 2018; 285:4104-4123. [PMID: 29806737 DOI: 10.1111/febs.14523] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/11/2018] [Accepted: 05/24/2018] [Indexed: 12/13/2022]
Abstract
One of the classic hallmarks of cancer is disruption of cell death signalling. Inhibition of cell death promotes tumour growth and metastasis, causes resistance to chemo- and radiotherapies as well as targeted agents, and is frequently due to overexpression of antiapoptotic proteins rather than loss of pro-apoptotic effectors. FLIP is a major apoptosis-regulatory protein frequently overexpressed in solid and haematological cancers, in which its high expression is often correlated with poor prognosis. FLIP, which is expressed as long (FLIP(L)) and short (FLIP(S)) splice forms, achieves its cell death regulatory functions by binding to FADD, a critical adaptor protein which links FLIP to the apical caspase in the extrinsic apoptotic pathway, caspase-8, in a number of cell death regulating complexes, such as the death-inducing signalling complexes (DISCs) formed by death receptors. FLIP also plays a key role (together with caspase-8) in regulating another form of cell death termed programmed necrosis or 'necroptosis', as well as in other key cellular processes that impact cell survival, including autophagy. In addition, FLIP impacts activation of the intrinsic mitochondrial-mediated apoptotic pathway by regulating caspase-8-mediated activation of the pro-apoptotic Bcl-2 family member Bid. It has been demonstrated that FLIP can not only inhibit death receptor-mediated apoptosis, but also cell death induced by a range of clinically relevant chemotherapeutic and targeted agents as well as ionizing radiation. More recently, key roles for FLIP in promoting the survival of immunosuppressive tumour-promoting immune cells have been discovered. Thus, FLIP is of significant interest as an anticancer therapeutic target. In this article, we review FLIP's biology and potential ways of targeting this important tumour and immune cell death regulator.
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Affiliation(s)
- Luke Humphreys
- Drug Resistance Group, Centre for Cancer Research & Cell Biology, Queen's University Belfast, Belfast, UK
| | - Margarita Espona-Fiedler
- Drug Resistance Group, Centre for Cancer Research & Cell Biology, Queen's University Belfast, Belfast, UK
| | - Daniel B Longley
- Drug Resistance Group, Centre for Cancer Research & Cell Biology, Queen's University Belfast, Belfast, UK
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17
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Choi CYU, Reimers K, Allmeling C, Kall S, Choi YH, Vogt PM. Inhibition of Apoptosis by Expression of Antiapoptotic Proteins in Recombinant Human Keratinocytes. Cell Transplant 2017; 16:663-674. [DOI: 10.3727/000000007783465037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The Fas ligand/Fas interaction plays an important role in the regulation of immune responses. Allografted cells undergo Fas-mediated apoptosis induced by CD8+ T cells. Our objective was to prevent human keratinocytes from immunologically induced apoptosis. We focused on three proteins with inhibitory function on Fas-mediated apoptosis. Human keratinocytes were transfected with either Flip, Faim, or Lifeguard (LFG). The treatment proved to be practicable and efficient. The recombinant keratinocytes with expression of our target proteins were cocultured with CD8+ T cells and the apoptotic activity was then evaluated. Activation of caspase-8 was detectable in control but not in the recombinant cells. Quantitative analysis revealed significant induction of T-cell-induced apoptosis in nontransfected keratinocytes (p = 0.04, n = 12) but not in Flip (p = 0.66), Faim (p = 0.42), or LFG (p = 0.44) expressing cells. Our results suggest that heterotopic expression of antiapoptotic proteins can induce the resistance of keratinocytes to a major mechanism of rejection.
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Affiliation(s)
- Claudia Y. U. Choi
- Department of Plastic, Hand and Reconstructive Surgery, Medical School Hannover, D-30625 Hannover, Germany
| | - Kerstin Reimers
- Department of Plastic, Hand and Reconstructive Surgery, Medical School Hannover, D-30625 Hannover, Germany
| | - Christina Allmeling
- Department of Plastic, Hand and Reconstructive Surgery, Medical School Hannover, D-30625 Hannover, Germany
| | - Susanne Kall
- Department of Plastic, Hand and Reconstructive Surgery, Medical School Hannover, D-30625 Hannover, Germany
| | - Yeong-Hoon Choi
- Department of Cardiac Surgery, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Peter M. Vogt
- Department of Plastic, Hand and Reconstructive Surgery, Medical School Hannover, D-30625 Hannover, Germany
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18
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Primary lymphocyte infection models for KSHV and its putative tumorigenesis mechanisms in B cell lymphomas. J Microbiol 2017; 55:319-329. [PMID: 28455586 DOI: 10.1007/s12275-017-7075-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 03/03/2017] [Accepted: 03/03/2017] [Indexed: 12/12/2022]
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is the latest addition to the human herpesvirus family. Unlike alpha- and beta-herpesvirus subfamily members, gamma-herpesviruses, including Epstein-Barr virus (EBV) and KSHV, cause various tumors in humans. KSHV primarily infects endothelial and B cells in vivo, and is associated with at least three malignancies: Kaposi's sarcoma and two B cell lymphomas, respectively. Although KSHV readily infects endothelial cells in vitro and thus its pathogenic mechanisms have been extensively studied, B cells had been refractory to KSHV infection. As such, functions of KSHV genes have mostly been elucidated in endothelial cells in the context of viral infection but not in B cells. Whether KSHV oncogenes, defined in endothelial cells, play the same roles in the tumorigenesis of B cells remains an open question. Only recently, through a few ground-breaking studies, B cell infection models have been established. In this review, those models will be compared and contrasted and putative mechanisms of KSHV-induced B cell transformation will be discussed.
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Williamson SJ, Nicol SM, Stürzl M, Sabbah S, Hislop AD. Azidothymidine Sensitizes Primary Effusion Lymphoma Cells to Kaposi Sarcoma-Associated Herpesvirus-Specific CD4+ T Cell Control and Inhibits vIRF3 Function. PLoS Pathog 2016; 12:e1006042. [PMID: 27893813 PMCID: PMC5125715 DOI: 10.1371/journal.ppat.1006042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 11/04/2016] [Indexed: 01/06/2023] Open
Abstract
Kaposi sarcoma-associated herpesvirus (KSHV) is linked with the development of Kaposi sarcoma and the B lymphocyte disorders primary effusion lymphoma (PEL) and multi-centric Castleman disease. T cell immunity limits KSHV infection and disease, however the virus employs multiple mechanisms to inhibit efficient control by these effectors. Thus KSHV-specific CD4+ T cells poorly recognize most PEL cells and even where they can, they are unable to kill them. To make KSHV-infected cells more sensitive to T cell control we treated PEL cells with the thymidine analogue azidothymidine (AZT), which sensitizes PEL lines to Fas-ligand and TRAIL challenge; effector mechanisms which T cells use. PELs co-cultured with KSHV-specific CD4+ T cells in the absence of AZT showed no control of PEL outgrowth. However in the presence of AZT PEL outgrowth was controlled in an MHC-restricted manner. To investigate how AZT sensitizes PELs to immune control we first examined BJAB cells transduced with individual KSHV-latent genes for their ability to resist apoptosis mediated by stimuli delivered through Fas and TRAIL receptors. This showed that in addition to the previously described vFLIP protein, expression of vIRF3 also inhibited apoptosis delivered by these stimuli. Importantly vIRF3 mediated protection from these apoptotic stimuli was inhibited in the presence of AZT as was a second vIRF3 associated phenotype, the downregulation of surface MHC class II. Although both vFLIP and vIRF3 are expressed in PELs, we propose that inhibiting vIRF3 function with AZT may be sufficient to restore T cell control of these tumor cells. Kaposi sarcoma-associated herpesvirus (KSHV) can cause disease in humans in the form of B lymphocyte disorders such as primary effusion lymphoma (PEL) and multicentric Castleman disease. Where tested, these are highly resistant to immune control by KSHV-specific T cells. To investigate how such KSHV-infected cells can be made more sensitive to T cell control we treated PEL lines with azidothymidine (AZT), which has been shown to induce sensitivity in such lines to the mechanisms which T cells use to kill targets. We found this allowed the T cells to control in vitro lymphoma growth. The ability of the T cells to control PEL cell growth was found to correlate with AZT mediated inhibition of function of the KSHV protein vIRF3 which we show has the ability to protect cells from killing by immune effector mechanisms. These studies suggest that the therapeutic drug AZT may be of use to tip the virus host balance away from the virus by interfering with this immune evasion and pro-survival protein, potentially allowing better control by the host.
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Affiliation(s)
- Samantha J. Williamson
- Institute of Immunology and Immunotherapy, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Samantha M. Nicol
- Institute of Immunology and Immunotherapy, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Michael Stürzl
- Division of Molecular and Experimental Surgery, Department of Surgery, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Shereen Sabbah
- Department of Immunobiology, King's College London, London, United Kingdom
| | - Andrew D. Hislop
- Institute of Immunology and Immunotherapy, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- * E-mail:
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20
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Abstract
Cancer has been recognized for thousands of years. Egyptians believed that cancer occurred at the will of the gods. Hippocrates believed human disease resulted from an imbalance of the four humors: blood, phlegm, yellow bile, and black bile with cancer being caused by excess black bile. The lymph theory of cancer replaced the humoral theory and the blastema theory replaced the lymph theory. Rudolph Virchow was the first to recognize that cancer cells like all cells came from other cells and believed chronic irritation caused cancer. At the same time there was a belief that trauma caused cancer, though it never evolved after many experiments inducing trauma. The birth of virology occurred in 1892 when Dimitri Ivanofsky demonstrated that diseased tobacco plants remained infective after filtering their sap through a filter that trapped bacteria. Martinus Beijerinck would call the tiny infective agent a virus and both Dimitri Ivanofsky and Marinus Beijerinck would become the fathers of virology. Not to long thereafter, Payton Rous founded the field of tumor virology in 1911 with his discovery of a transmittable sarcoma of chickens by what would come to be called Rous sarcoma virus or RSV for short. The first identified human tumor virus was the Epstein-Barr virus (EBV), named after Tony Epstein and Yvonne Barr who visualized the virus particles in Burkitt's lymphoma cells by electron microscopy in 1965. Since that time, many viruses have been associated with carcinogenesis including the most studied, human papilloma virus associated with cervical carcinoma, many other anogenital carcinomas, and oropharyngeal carcinoma. The World Health Organization currently estimates that approximately 22% of worldwide cancers are attributable to infectious etiologies, of which viral etiologies is estimated at 15-20%. The field of tumor virology/viral carcinogenesis has not only identified viruses as etiologic agents of human cancers, but has also given molecular insights to all human cancers including the oncogene activation and tumor suppressor gene inactivation.
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Affiliation(s)
- A J Smith
- Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - L A Smith
- Texas Tech University Health Sciences Center, Lubbock, TX, United States.
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21
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Nuclear Innate Immune DNA Sensor IFI16 Is Degraded during Lytic Reactivation of Kaposi's Sarcoma-Associated Herpesvirus (KSHV): Role of IFI16 in Maintenance of KSHV Latency. J Virol 2016; 90:8822-41. [PMID: 27466416 PMCID: PMC5021400 DOI: 10.1128/jvi.01003-16] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/13/2016] [Indexed: 12/17/2022] Open
Abstract
UNLABELLED IFI16 (interferon gamma-inducible protein 16) recognizes nuclear episomal herpesvirus (Kaposi's sarcoma-associated herpesvirus [KSHV], Epstein-Barr virus [EBV], and herpes simplex virus 1 [HSV-1]) genomes and induces the inflammasome and interferon beta responses. It also acts as a lytic replication restriction factor and inhibits viral DNA replication (human cytomegalovirus [HCMV] and human papillomavirus [HPV]) and transcription (HSV-1, HCMV, and HPV) through epigenetic modifications of the viral genomes. To date, the role of IFI16 in the biology of latent viruses is not known. Here, we demonstrate that knockdown of IFI16 in the latently KSHV-infected B-lymphoma BCBL-1 and BC-3 cell lines results in lytic reactivation and increases in levels of KSHV lytic transcripts, proteins, and viral genome replication. Similar results were also observed during KSHV lytic cycle induction in TREX-BCBL-1 cells with the doxycycline-inducible lytic cycle switch replication and transcription activator (RTA) gene. Overexpression of IFI16 reduced lytic gene induction by the chemical agent 12-O-tetradecoylphorbol-13-acetate (TPA). IFI16 protein levels were significantly reduced or absent in TPA- or doxycycline-induced cells expressing lytic KSHV proteins. IFI16 is polyubiquitinated and degraded via the proteasomal pathway. The degradation of IFI16 was absent in phosphonoacetic acid-treated cells, which blocks KSHV DNA replication and, consequently, late lytic gene expression. Chromatin immunoprecipitation assays of BCBL-1 and BC-3 cells demonstrated that IFI16 binds to KSHV gene promoters. Uninfected epithelial SLK and osteosarcoma U2OS cells transfected with KSHV luciferase promoter constructs confirmed that IFI16 functions as a transcriptional repressor. These results reveal that KSHV utilizes the innate immune nuclear DNA sensor IFI16 to maintain its latency and repression of lytic transcripts, and a late lytic KSHV gene product(s) targets IFI16 for degradation during lytic reactivation. IMPORTANCE Like all herpesviruses, latency is an integral part of the life cycle of Kaposi's sarcoma-associated herpesvirus (KSHV), an etiological agent for many human cancers. Herpesviruses utilize viral and host factors to successfully evade the host immune system to maintain latency. Reactivation is a complex event where the latent episomal viral genome springs back to active transcription of lytic cycle genes. Our studies reveal that KSHV has evolved to utilize the innate immune sensor IFI16 to keep lytic cycle transcription in dormancy. We demonstrate that IFI16 binds to the lytic gene promoter, acts as a transcriptional repressor, and thereby helps to maintain latency. We also discovered that during the late stage of lytic replication, KSHV selectively degrades IFI16, thus relieving transcriptional repression. This is the first report to demonstrate the role of IFI16 in latency maintenance of a herpesvirus, and further understanding will lead to the development of strategies to eliminate latent infection.
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Kim JH, Kim MJ, Choi KC, Son J. Quercetin sensitizes pancreatic cancer cells to TRAIL-induced apoptosis through JNK-mediated cFLIP turnover. Int J Biochem Cell Biol 2016; 78:327-334. [DOI: 10.1016/j.biocel.2016.07.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 07/27/2016] [Indexed: 10/21/2022]
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Jha HC, Banerjee S, Robertson ES. The Role of Gammaherpesviruses in Cancer Pathogenesis. Pathogens 2016; 5:pathogens5010018. [PMID: 26861404 PMCID: PMC4810139 DOI: 10.3390/pathogens5010018] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Accepted: 01/27/2016] [Indexed: 12/15/2022] Open
Abstract
Worldwide, one fifth of cancers in the population are associated with viral infections. Among them, gammaherpesvirus, specifically HHV4 (EBV) and HHV8 (KSHV), are two oncogenic viral agents associated with a large number of human malignancies. In this review, we summarize the current understanding of the molecular mechanisms related to EBV and KSHV infection and their ability to induce cellular transformation. We describe their strategies for manipulating major cellular systems through the utilization of cell cycle, apoptosis, immune modulation, epigenetic modification, and altered signal transduction pathways, including NF-kB, Notch, Wnt, MAPK, TLR, etc. We also discuss the important EBV latent antigens, namely EBNA1, EBNA2, EBNA3’s and LMP’s, which are important for targeting these major cellular pathways. KSHV infection progresses through the engagement of the activities of the major latent proteins LANA, v-FLIP and v-Cyclin, and the lytic replication and transcription activator (RTA). This review is a current, comprehensive approach that describes an in-depth understanding of gammaherpes viral encoded gene manipulation of the host system through targeting important biological processes in viral-associated cancers.
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Affiliation(s)
- Hem Chandra Jha
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Shuvomoy Banerjee
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
| | - Erle S Robertson
- Department of Microbiology and Tumor Virology Program, Abramson Comprehensive Cancer Center, Perelman School of Medicine at the University of Pennsylvania, 201E Johnson Pavilion, 3610, Hamilton Walk, Philadelphia, PA 19104, USA.
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Zhang YP, Kong QH, Huang Y, Wang GL, Chang KJ. Inhibition of c-FLIP by RNAi enhances sensitivity of the human osteogenic sarcoma cell line U2OS to TRAIL-induced apoptosis. Asian Pac J Cancer Prev 2016; 16:2251-6. [PMID: 25824746 DOI: 10.7314/apjcp.2015.16.6.2251] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
To study effects of cellular FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein (c-FLIP) inhibition by RNA interference (RNAi) on sensitivity of U2OS cells to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-induced apoptosis, plasmid pSUPER-c-FLIP-siRNA was constructed and then transfected into U2OS cells. A stable transfection cell clone U2OS/pSUPER-c-FLIP-siRNA was screened from the c-FLIP-siRNA transfected cells. RT-PCR and Western blotting were applied to measure the expression of c-FLIP at the levels of mRNA and protein. The results indicated that the expression of c-FLIP was significantly suppressed by the c-FLIP-siRNA in the cloned U2OS/pSUPER-c-FLIP-siRNA as compared with the control cells of U2OS/pSUPER. The cloned cell line of U2OS/pSUPER-c-FLIP-siRNA was further examined for TRAIL- induced cell death and apoptosis in the presence of a pan-antagonist of inhibitor of apoptosis proteins (IAPs) AT406, with or without 4 hrs pretreatment with rocaglamide, an inhibitor of c-FLIP biosynthesis, for 24 hrs. Cell death effects and apoptosis were measured by the methods of MTT assay with 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide and flow cytometry, respectively. The results indicated that TRAIL-induced cell death in U2OS/pSUPER-c-FLIP-siRNA was increased compared with control cells U2OS/pSUPER in the presence or absence of AT406. Flow cytometry indicated that TRAIL-induced cell death effects proceeded through cell apoptosis pathway. However, in the presence of rocaglamide, cell death or apoptotic effects of TRAIL were similar and profound in both cell lines, suggesting that the mechanism of action for both c-FLIP-siRNA and rocaglamide was identical. We conclude that the inhibition of c-FLIP by either c-FLIP-siRNA or rocaglamide can enhance the sensitivity of U2OS to TRAIL-induced apopotosis, suggesting that inhibition of c-FLIP is a good target for anti-cancer therapy.
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Affiliation(s)
- Ya-Ping Zhang
- Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, China E-mail : ,
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Sousa-Squiavinato ACM, Silvestre RN, Elgui De Oliveira D. Biology and oncogenicity of the Kaposi sarcoma herpesvirus K1 protein. Rev Med Virol 2015; 25:273-85. [PMID: 26192396 DOI: 10.1002/rmv.1843] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 06/01/2015] [Accepted: 06/02/2015] [Indexed: 12/30/2022]
Abstract
The Kaposi sarcoma-associated herpesvirus (KSHV), or human herpesvirus 8, is a gammaherpesvirus etiologically linked to the development of Kaposi sarcoma, primary effusion lymphomas, and multicentric Castleman disease in humans. KSHV is unique among other human herpesviruses because of the elevated number of viral products that mimic human cellular proteins, such as a viral cyclin, a viral G protein-coupled receptor, anti-apoptotic proteins (e.g., v-bcl2 and v-FLIP), viral interferon regulatory factors, and CC chemokine viral homologues. Several KSHV products have oncogenic properties, including the transmembrane K1 glycoprotein. KSHV K1 is encoded in the viral ORFK1, which is the most variable portion of the viral genome, commonly used to discriminate among viral genotypes. The extracellular region of K1 has homology with the light chain of lambda immunoglobulin, and its cytoplasmic region contains an immunoreceptor tyrosine-based activation motif (ITAM). KSHV K1 ITAM activates several intracellular signaling pathways, notably PI3K/AKT. Consequently, K1 expression inhibits proapoptotic proteins and increases the life-span of KSHV-infected cells. Another remarkable effect of K1 activity is the production of inflammatory cytokines and proangiogenic factors, such as vascular endothelial growth factor. KSHV K1 immortalizes primary human endothelial cells and transforms rodent fibroblasts in vitro; moreover, K1 induces tumors in vivo in transgenic mice expressing this viral protein. This review aims to consolidate and discuss the current knowledge on this intriguing KSHV protein, focusing on activities of K1 that can contribute to the pathogenesis of KSHV-associated human cancers.
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Affiliation(s)
| | - Renata Nacasaki Silvestre
- Viral Carcinogenesis and Cancer Biology Research Group (ViriCan) at Botucatu Medical School, São Paulo State University (UNESP), Botucatu, SP, Brazil
| | - Deilson Elgui De Oliveira
- Viral Carcinogenesis and Cancer Biology Research Group (ViriCan) at Botucatu Medical School, São Paulo State University (UNESP), Botucatu, SP, Brazil.,Biotechnology Institute (IBTEC), São Paulo State University (UNESP), Botucatu, SP, Brazil
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Interference with the Autophagic Process as a Viral Strategy to Escape from the Immune Control: Lesson from Gamma Herpesviruses. J Immunol Res 2015; 2015:546063. [PMID: 26090494 PMCID: PMC4451563 DOI: 10.1155/2015/546063] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 04/13/2015] [Accepted: 04/28/2015] [Indexed: 12/14/2022] Open
Abstract
We summarized the most recent findings on the role of autophagy in antiviral immune response. We described how viruses have developed strategies to subvert the autophagic process. A particular attention has been given to Epstein-Barr and Kaposi's sarcoma associated Herpesvirus, viruses studied for many years in our laboratory. These two viruses belong to γ-Herpesvirus subfamily and are associated with several human cancers. Besides the effects on the immune response, we have described how autophagy subversion by viruses may also concur to the enhancement of their replication and to viral tumorigenesis.
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Abstract
Molluscum contagiosum virus (MCV) is the causative agent of molluscum contagiosum (MC), the third most common viral skin infection in children, and one of the five most prevalent skin diseases worldwide. No FDA-approved treatments, vaccines, or commercially available rapid diagnostics for MCV are available. This review discusses several aspects of this medically important virus including: physical properties of MCV, MCV pathogenesis, MCV replication, and immune responses to MCV infection. Sequencing of the MCV genome revealed novel immune evasion molecules which are highlighted here. Special attention is given to the MCV MC159 and MC160 proteins. These proteins are FLIPs with homologs in gamma herpesviruses and in the cell. They are of great interest because each protein regulates apoptosis, NF-κB, and IRF3. However, the mechanism that each protein uses to impart its effects is different. It is important to elucidate how MCV inhibits immune responses; this knowledge contributes to our understanding of viral pathogenesis and also provides new insights into how the immune system neutralizes virus infections.
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28
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Abstract
Cellular apoptosis is of major importance in the struggle between virus and host. Although many viruses use various strategies to control the cell death machinery by encoding anti-apoptotic virulence factors, it is now becoming clear that, in addition to their role in inhibiting apoptosis, these factors function in multiple immune and metabolic pathways to promote fitness and pathogenesis. In this Progress article, we discuss novel functions of viral anti-apoptotic factors in the regulation of autophagy, in the nuclear factor-κB (NF-κB) pathway and in interferon signalling, with a focus on persistent and oncogenic gammaherpesviruses. If viral anti-apoptotic proteins are to be properly exploited as targets for antiviral drugs, their diverse and complex roles should be considered.
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Affiliation(s)
- Chengyu Liang
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, California 90033, USA
| | - Byung-Ha Oh
- Department of Biological Sciences, KAIST Institute for the Biocentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
| | - Jae U Jung
- Department of Molecular Microbiology and Immunology, University of Southern California, Los Angeles, California 90033, USA
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Wang Y, Tu Y, Lu J, Tao J, Li Y. c-FLIPp43 induces activation of the nuclear factor‑κB signaling pathway in a dose-dependent manner in the A375 melanoma cell line. Mol Med Rep 2014; 10:1438-42. [PMID: 25017325 DOI: 10.3892/mmr.2014.2364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 05/19/2014] [Indexed: 11/06/2022] Open
Abstract
In order to investigate the role of c‑FLIPp43 in the regulation of the nuclear factor (NF)‑κB signaling pathway in melanoma cell lines, a eukaryotic expression vector for c‑FLIPp43 was constructed with the pCMV‑Tag2B plasmid. The monoclonal A375 cells with stable expression of c‑FLIPp43 were obtained by G418 selection and were identified with western blot analysis. The protein level of NF‑κBp65 in the A375 cell line with stable expression of c‑FLIPp43 was examined by western blot analysis. The translocation of NF‑κBp65 was examined using immunofluorescence. The A375 cell lines were transfected with the pCMV‑Tag2B‑cFLIPp43 vector at different doses and the activation of the NF‑κB signaling pathway was examined by the dual‑luciferase reporter assay system. The stable expression of c‑FLIPp43 in the A375 cell lines transfected with the pCMV‑Tag2B‑cFLIPp43 vector increased the protein level of NF‑κBp65 compared with in the A375 cell lines transfected with the empty vector. Transfection of the cells using the pCMV‑Tag2B‑cFLIPp43 vector increased the amount of NF‑κBp65 in the nucleus in a dose‑dependent manner. In conclusion, the transfection of the c‑FLIPp43 expression vector induces the protein expression of NF‑κBp65 and promotes the activation of the NF‑κB signaling pathway in the A375 melanoma cell line.
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Affiliation(s)
- Yujue Wang
- Department of Dermatology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yating Tu
- Department of Dermatology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Jiejie Lu
- Department of Dermatology and Venereology, Hainan Provincial Center for Skin Disease and STD Control, Haikou, Hainan 570206, P.R. China
| | - Juan Tao
- Department of Dermatology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
| | - Yan Li
- Department of Dermatology, Affiliated Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China
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30
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Wallin RPA, Sundquist VS, Bråkenhielm E, Cao Y, Ljunggren HG, Grandien A. Angiostatic effects of NK cell-derived IFN-γ counteracted by tumour cell Bcl-xL expression. Scand J Immunol 2014; 79:90-7. [PMID: 24313893 DOI: 10.1111/sji.12134] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 10/16/2013] [Indexed: 01/13/2023]
Abstract
Anti-apoptotic proteins that block death receptor-mediated apoptosis favour tumour evasion of the immune system, leading to enhanced tumour progression. However, it is unclear whether blocking the mitochondrial pathway of apoptosis will protect tumours from immune cell attack. Here, we report that the anti-apoptotic protein Bcl-xL , known for its ability to block the mitochondrial pathway of apoptosis, exerted tumour-progressive activity in a murine lymphoma model. Bcl-xL overexpressing tumours exhibited a more aggressive development than control tumours. Surprisingly, Bcl-xL protection of tumours from NK cell-mediated attack did not involve protection from NK cell-mediated cytotoxicity. Instead, Bcl-xL -blocked apoptosis resulting from hypoxia and/or nutrient loss associated with the inhibition of angiogenesis caused by NK cell-secreted IFN-γ. These results support the notion that NK cells may inhibit tumour growth also by mechanisms other than direct cytotoxicity. Hence, the present results unravel a pathway by which tumours with a block in the mitochondrial pathway of apoptosis can evade the immune system.
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Affiliation(s)
- R P A Wallin
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden; Department of Microbiology Tumor- and Cell- Biology, Karolinska Institutet, Stockholm, Sweden; Indonesia International Institute for Life-Sciences, Jakarta Timur, Jakarta, Indonesia
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31
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Cesarman E. Gammaherpesviruses and Lymphoproliferative Disorders. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2014; 9:349-72. [DOI: 10.1146/annurev-pathol-012513-104656] [Citation(s) in RCA: 147] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ethel Cesarman
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065;
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32
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Cousins E, Nicholas J. Molecular biology of human herpesvirus 8: novel functions and virus-host interactions implicated in viral pathogenesis and replication. Recent Results Cancer Res 2014; 193:227-68. [PMID: 24008302 PMCID: PMC4124616 DOI: 10.1007/978-3-642-38965-8_13] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus (KSHV), is the second identified human gammaherpesvirus. Like its relative Epstein-Barr virus, HHV-8 is linked to B-cell tumors, specifically primary effusion lymphoma and multicentric Castleman's disease, in addition to endothelial-derived KS. HHV-8 is unusual in its possession of a plethora of "accessory" genes and encoded proteins in addition to the core, conserved herpesvirus and gammaherpesvirus genes that are necessary for basic biological functions of these viruses. The HHV-8 accessory proteins specify not only activities deducible from their cellular protein homologies but also novel, unsuspected activities that have revealed new mechanisms of virus-host interaction that serve virus replication or latency and may contribute to the development and progression of virus-associated neoplasia. These proteins include viral interleukin-6 (vIL-6), viral chemokines (vCCLs), viral G protein-coupled receptor (vGPCR), viral interferon regulatory factors (vIRFs), and viral antiapoptotic proteins homologous to FLICE (FADD-like IL-1β converting enzyme)-inhibitory protein (FLIP) and survivin. Other HHV-8 proteins, such as signaling membrane receptors encoded by open reading frames K1 and K15, also interact with host mechanisms in unique ways and have been implicated in viral pathogenesis. Additionally, a set of micro-RNAs encoded by HHV-8 appear to modulate expression of multiple host proteins to provide conditions conducive to virus persistence within the host and could also contribute to HHV-8-induced neoplasia. Here, we review the molecular biology underlying these novel virus-host interactions and their potential roles in both virus biology and virus-associated disease.
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Affiliation(s)
- Emily Cousins
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, 1650 Orleans Street, Baltimore, MD, 21287, USA,
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33
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Sachanas S, Levidou G, Angelopoulou MK, Moschogiannis M, Yiakoumis X, Kalpadakis C, Vassilakopoulos TP, Kontopidou F, Tsirkinidis P, Dimitrakopoulou A, Kokoris S, Dimitriadou E, Kyrtsonis MC, Panayiotidis P, Papadaki H, Patsouris E, Korkolopoulou P, Pangalis GA. Apoptotic and proliferative characteristics of proliferation centers in lymph node sections of patients with chronic lymphocytic leukemia. Leuk Lymphoma 2013; 55:571-82. [PMID: 23697878 DOI: 10.3109/10428194.2013.806802] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We have analyzed the immunohistochemical expression of a wide range of molecules along with the proliferation rate separately in the proliferation centers (PCs) and in the rest of the tumor area, in lymph node or spleen sections of patients with chronic lymphocytic leukemia (CLL). Fas, FasL and c-FLIP were observed both within and outside the PCs in all cases. However, only the difference in FasL expression between the PCs and the non-PC areas attained statistical significance. Median survivin expression in the PCs was higher compared to the non-PC areas. Cleaved caspase 3 was expressed at very low levels both within and outside PCs, while BCL-2 protein was expressed at high levels in all cases in both tumor compartments. Multivariate analysis demonstrated that concurrent overexpression of Fas/FasL/c-FLIP in the PCs was correlated with worse outcome for progression-free survival as well as for overall survival.
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34
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Feng P, Moses A, Früh K. Evasion of adaptive and innate immune response mechanisms by γ-herpesviruses. Curr Opin Virol 2013; 3:285-95. [PMID: 23735334 DOI: 10.1016/j.coviro.2013.05.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/01/2013] [Accepted: 05/14/2013] [Indexed: 01/05/2023]
Abstract
γ-Herpesviral immune evasion mechanisms are optimized to support the acute, lytic and the longterm, latent phase of infection. During acute infection, specific immune modulatory proteins limit, but also exploit, the antiviral activities of cell intrinsic innate immune responses as well as those of innate and adaptive immune cells. During latent infection, a restricted gene expression program limits immune targeting and cis-acting mechanisms to reduce the antigen presentation as well as antigenicity of latency-associated proteins. Here, we will review recent progress in our understanding of γ-herpesviral immune evasion strategies.
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Affiliation(s)
- Pinghui Feng
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA 90089, USA
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35
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Golan-Gerstl R, Wallach-Dayan SB, Zisman P, Cardoso WV, Goldstein RH, Breuer R. Cellular FLICE-like inhibitory protein deviates myofibroblast fas-induced apoptosis toward proliferation during lung fibrosis. Am J Respir Cell Mol Biol 2012; 47:271-9. [PMID: 22582174 DOI: 10.1165/rcmb.2010-0284rc] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A prominent feature of fibrotic tissue in general and of lungs in particular is fibroblast proliferation and accumulation. In patients overcoming fibrosis, apoptosis limits this excessive cell growth. We have previously shown resistance to Fas-induced apoptosis of primary lung fibroblasts from mice with bleomycin-induced lung fibrosis, their escape from immune surveillance, and continued accumulation in spite of overexpression of the Fas death receptor. Cellular FLICE-like inhibitory protein (c-FLIP) is a regulator of cell death receptor-induced apoptosis in many cell types. We aimed to determine c-FLIP levels in myofibroblasts from fibrotic lungs and to directly assess c-FLIP's role in apoptosis and proliferation of primary lung myofibroblasts. c-FLIP levels were determined by apoptosis gene array, flow cytometry, Western blot, and immunofluorescence before and after down-regulation with a specific small interfering RNA. Apoptosis was assessed by caspase cleavage in Western blot and by Annexin V affinity labeling after FACS and tissue immunofluorescence. Proliferation was assessed by BrdU uptake, also using FACS and immunofluorescence. We show that myofibroblasts from lungs of humans with idiopathic pulmonary fibrosis and from bleomycin-treated versus normal saline-treated mice up-regulate c-FLIP levels. Using the animal model, we show that fibrotic lung myofibroblasts divert Fas signaling from apoptosis to proliferation and that this requires signaling by TNF receptor-associated factor (TRAF) and NF-κB. c-FLIP down-regulation reverses the effect of Fas activation, causing increased apoptosis, decreased proliferation, and diminished recruitment of TRAF to the DISC complex. This indicates that c-FLIP is essential for myofibroblast accumulation and may serve as a potential target to manipulate tissue fibrosis.
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Affiliation(s)
- Regina Golan-Gerstl
- Lung Cellular and Molecular Laboratory, Institute of Pulmonary Medicine, Hadassah University Hospital, POB 12000, Jerusalem, Israel
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36
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Cdk1 inhibition induces mutually inhibitory apoptosis and reactivation of Kaposi's sarcoma-associated herpesvirus. J Virol 2012; 86:6668-76. [PMID: 22496227 DOI: 10.1128/jvi.06240-11] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Primary effusion lymphoma (PEL) cells are predominantly infected by the latent form of Kaposi's sarcoma-associated herpesvirus (KSHV), with virus reactivation occurring in a small percentage of cells. Latency enables KSHV to persist in the host cell and promotes tumorigenesis through viral gene expression, thus presenting a major barrier to the elimination of KSHV and the treatment of PEL. Therefore, it is important to identify cellular genes that are essential for PEL cell survival or the maintenance of KSHV latency. Here we report that cyclin-dependent kinase 1 (Cdk1) inhibition can induce both apoptosis and KSHV reactivation in a population of PEL cells. Caspases, but not p53, are required for PEL cell apoptosis induced by Cdk1 inhibition. p38 kinase is activated by Cdk1 inhibition and mediates KSHV reactivation. Interestingly, upon Cdk1 inhibition, KSHV is reactivated predominantly in the nonapoptotic subpopulation of PEL cells. We provide evidence that this is due to mutual inhibition between apoptosis and KSHV reactivation. In addition, we found that KSHV reactivation activates protein kinase B (AKT/PKB), which promotes cell survival and facilitates KSHV reactivation. Our study thus establishes a key role for Cdk1 in PEL cell survival and the maintenance of KSHV latency and reveals a multifaceted relationship between KSHV reactivation and PEL cell apoptosis.
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37
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Wang YF, Chiou YH, Wang LY, Chang ST, Shyu HW, Chen CY, Lin KH, Chou MC. Cisplatin disrupts the latency of human herpesvirus 8 and induces apoptosis in primary effusion lymphoma cells. Cancer Invest 2012; 30:268-74. [PMID: 22480174 DOI: 10.3109/07357907.2012.657813] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Human herpesvirus 8 (HHV8) is the etiologic agent for primary effusion lymphoma (PEL). The aim of this study is to investigate the effects of cisplatin on the PEL cells. Cisplatin treatment induced apoptosis and inhibited the growth of PEL cells, and the effect was more profound in the HHV8-positive lymphoma cells compared with the EBV-positive lymphoma cells. Cisplatin treatment decreased the expression of HHV8 latent genes and activated p53 at serine 15 in PEL cells. Our results indicate that cisplatin can disrupt HHV8 latency and induce reactivation of p53 and highly selective treatment modality for this virally induced lymphoma.
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Affiliation(s)
- Yi-Fen Wang
- Department of Medical Laboratory Sciences and Biotechnology, Fooyin-University, Kaohsiung, Taiwan, ROC.
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38
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Lee HR, Brulois K, Wong L, Jung JU. Modulation of Immune System by Kaposi's Sarcoma-Associated Herpesvirus: Lessons from Viral Evasion Strategies. Front Microbiol 2012; 3:44. [PMID: 22403573 PMCID: PMC3293256 DOI: 10.3389/fmicb.2012.00044] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Accepted: 01/27/2012] [Indexed: 12/14/2022] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV), a member of the herpesvirus family, has evolved to establish a long-term, latent infection of cells such that while they carry the viral genome gene expression is highly restricted. Latency is a state of cryptic viral infection associated with genomic persistence in their host and this hallmark of KSHV infection leads to several clinical-epidemiological diseases such as KS, a plasmablastic variant of multicentric Castleman's disease, and primary effusion lymphoma upon immune suppression of infected hosts. In order to sustain efficient life-long persistency as well as their life cycle, KSHV dedicates a large portion of its genome to encode immunomodulatory proteins that antagonize its host's immune system. In this review, we will describe our current knowledge of the immune evasion strategies employed by KSHV at distinct stages of its viral life cycle to control the host's immune system.
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Affiliation(s)
- Hye-Ra Lee
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California Los Angeles, CA, USA
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Högstrand K, Hejll E, Sander B, Rozell B, Larsson LG, Grandien A. Inhibition of the intrinsic but not the extrinsic apoptosis pathway accelerates and drives MYC-driven tumorigenesis towards acute myeloid leukemia. PLoS One 2012; 7:e31366. [PMID: 22393362 PMCID: PMC3290626 DOI: 10.1371/journal.pone.0031366] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 01/09/2012] [Indexed: 11/18/2022] Open
Abstract
Myc plays an important role in tumor development, including acute myeloid leukemia (AML). However, MYC is also a powerful inducer of apoptosis, which is one of the major failsafe programs to prevent cancer development. To clarify the relative importance of the extrinsic (death receptor-mediated) versus the intrinsic (mitochondrial) pathway of apoptosis in MYC-driven AML, we coexpressed MYC together with anti-apoptotic proteins of relevance for AML; BCL-X(L)/BCL-2 (inhibiting the intrinsic pathway) or FLIP(L) (inhibiting the extrinsic pathway), in hematopoietic stems cells (HSCs). Transplantation of HSCs expressing MYC into syngeneic recipient mice resulted in development of AML and T-cell lymphomas within 7-9 weeks as expected. Importantly, coexpression of MYC together with BCL-X(L)/BCL-2 resulted in strongly accelerated kinetics and favored tumor development towards aggressive AML. In contrast, coexpression of MYC and FLIP(L) did neither accelerate tumorigenesis nor change the ratio of AML versus T-cell lymphoma. However, a change in distribution of immature CD4(+)CD8(+) versus mature CD4(+) T-cell lymphoma was observed in MYC/FLIP(L) mice, possibly as a result of increased survival of the CD4+ population, but this did not significantly affect the outcome of the disease. In conclusion, our findings provide direct evidence that BCL-X(L) and BCL-2 but not FLIP(L) acts in synergy with MYC to drive AML development.
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Affiliation(s)
- Kari Högstrand
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Center for Hematology and Regenerative Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Eduar Hejll
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
| | - Birgitta Sander
- Divisions of Clinical Research Center and Pathology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Björn Rozell
- Divisions of Clinical Research Center and Pathology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Lars-Gunnar Larsson
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden
| | - Alf Grandien
- Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Center for Hematology and Regenerative Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- * E-mail:
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Scudiero I, Zotti T, Ferravante A, Vessichelli M, Reale C, Masone MC, Leonardi A, Vito P, Stilo R. Tumor necrosis factor (TNF) receptor-associated factor 7 is required for TNFα-induced Jun NH2-terminal kinase activation and promotes cell death by regulating polyubiquitination and lysosomal degradation of c-FLIP protein. J Biol Chem 2012; 287:6053-61. [PMID: 22219201 PMCID: PMC3285372 DOI: 10.1074/jbc.m111.300137] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 12/27/2011] [Indexed: 01/29/2023] Open
Abstract
The pro-inflammatory cytokine tumor necrosis factor (TNF) α signals both cell survival and death. The biological outcome of TNFα treatment is determined by the balance between survival factors and Jun NH(2)-terminal kinase (JNK) signaling, which promotes cell death. Here, we show that TRAF7, the most recently identified member of the TNF receptor-associated factors (TRAFs) family of proteins, is essential for activation of JNK following TNFα stimulation. We also show that TRAF6 and TRAF7 promote unconventional polyubiquitination of the anti-apoptotic protein c-FLIP(L) and demonstrate that degradation of c-FLIP(L) also occurs through a lysosomal pathway. RNA interference-mediated depletion of TRAF7 correlates with increased c-FLIP(L) expression level, which, in turn, results in resistance to TNFα cytotoxicity. Collectively, our results indicate an important role for TRAF7 in the activation of JNK following TNFα stimulation and clearly point to an involvement of this protein in regulating the turnover of c-FLIP and, consequently, cell death.
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Affiliation(s)
- Ivan Scudiero
- From the Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università degli Studi del Sannio, Via Port'Arsa 11, Benevento 82100
- the Biogem Consortium, Via Camporeale, Ariano Irpino 83031, and
| | - Tiziana Zotti
- From the Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università degli Studi del Sannio, Via Port'Arsa 11, Benevento 82100
- the Biogem Consortium, Via Camporeale, Ariano Irpino 83031, and
| | - Angela Ferravante
- From the Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università degli Studi del Sannio, Via Port'Arsa 11, Benevento 82100
- the Biogem Consortium, Via Camporeale, Ariano Irpino 83031, and
| | - Mariangela Vessichelli
- From the Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università degli Studi del Sannio, Via Port'Arsa 11, Benevento 82100
- the Biogem Consortium, Via Camporeale, Ariano Irpino 83031, and
| | - Carla Reale
- From the Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università degli Studi del Sannio, Via Port'Arsa 11, Benevento 82100
- the Biogem Consortium, Via Camporeale, Ariano Irpino 83031, and
| | - Maria C. Masone
- From the Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università degli Studi del Sannio, Via Port'Arsa 11, Benevento 82100
- the Biogem Consortium, Via Camporeale, Ariano Irpino 83031, and
| | - Antonio Leonardi
- the Dipartimento di Biologia e Patologia Cellulare e Molecolare, Università degli Studi di Napoli “Federico II,” Via Pansini 5, Napoli 80131, Italy
| | - Pasquale Vito
- From the Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università degli Studi del Sannio, Via Port'Arsa 11, Benevento 82100
- the Biogem Consortium, Via Camporeale, Ariano Irpino 83031, and
| | - Romania Stilo
- From the Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università degli Studi del Sannio, Via Port'Arsa 11, Benevento 82100
- the Biogem Consortium, Via Camporeale, Ariano Irpino 83031, and
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Abstract
OBJECTIVE To report a case of a human immunodeficiency virus (HIV)-negative Kaposi sarcoma (KS) associated with Cushing disease (CD). METHODS The details of case presentation, evaluation, diagnosis, and treatment are presented and cases of KS and CD published before November 1, 2010 on PubMed and Scopus are reviewed. RESULTS A 54-year-old Hispanic HIV-negative man presented with typical signs and symptoms of CD (easy bruisability, proximal muscle wasting, and abdominal fat pads). Numerous raised, purplish, nonblanching plaques 0.5 to 2 cm in diameter extended throughout his lower extremities. Biochemical tests and pituitary magnetic resonance imaging confirmed CD. A lesion biopsy showed atypical vascular proliferation positive by immunohistochemistry for human herpesvirus 8 (HHV-8), consistent with KS. He underwent 2 transsphenoidal surgeries followed by a bilateral adrenalectomy. After recovery, his KS was treated with a systemic combination of liposomal doxorubicin and paclitaxel. CONCLUSION The occurrence of CD and KS is rare. Specific therapy for CD and chemotherapy for KS are effective in the treatment of KS associated with CD.
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Affiliation(s)
- Leo Jeng
- Department of Medicine, Division of Endocrinology, University of Texas Health Science Center at Houston, Houston, Texas 77030, USA.
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T-cell immunity to Kaposi sarcoma-associated herpesvirus: recognition of primary effusion lymphoma by LANA-specific CD4+ T cells. Blood 2012; 119:2083-92. [PMID: 22234686 DOI: 10.1182/blood-2011-07-366476] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
T-cell immunity is important for controlling Kaposi sarcoma-associated herpesvirus (KSHV) diseases such as the endothelial cell malignancy Kaposi sarcoma, or the B-cell malignancy, primary effusion lymphoma (PEL). However, little is known about KSHV-specific T-cell immunity in healthy donors and immune control of disease. Using PBMCs from healthy KSHV-infected donors, we found weak ex vivo responses to the KSHV latent antigens LANA, vFLIP, vCyclin, and Kaposin, with LANA most frequently recognized. CD4(+) T-cell clones specific to LANA, a protein expressed in all KSHV-infected cells and malignancies, were established to determine whether they could recognize LANA-expressing cells. B-cell targets expressing or fed LANA protein were consistently recognized by the clones; however, most PEL cell lines were not. PELs express the KSHV protein vIRF3 that inhibits promoter function of the HLA class II transactivator, decreasing expression of genes controlled by this transactivator. Re-expressing the class II transactivator in the PELs increased expression of downstream targets such as HLA class II and restored recognition but not killing by the LANA-specific clones. We suggest that PELs are poorly controlled in vivo because of inefficient recognition and killing by T cells.
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43
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Everly D, Sharma-Walia N, Sadagopan S, Chandran B. Herpesviruses and Cancer. CANCER ASSOCIATED VIRUSES 2012:133-167. [DOI: 10.1007/978-1-4614-0016-5_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Ewald F, Ueffing N, Brockmann L, Hader C, Telieps T, Schuster M, Schulz WA, Schmitz I. The role of c-FLIP splice variants in urothelial tumours. Cell Death Dis 2011; 2:e245. [PMID: 22190004 PMCID: PMC3252741 DOI: 10.1038/cddis.2011.131] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 11/16/2011] [Indexed: 01/01/2023]
Abstract
Deregulation of apoptosis is common in cancer and is often caused by overexpression of anti-apoptotic proteins in tumour cells. One important regulator of apoptosis is the cellular FLICE-inhibitory protein (c-FLIP), which is overexpressed, for example, in melanoma and Hodgkin's lymphoma cells. Here, we addressed the question whether deregulated c-FLIP expression in urothelial carcinoma impinges on the ability of death ligands to induce apoptosis. In particular, we investigated the role of the c-FLIP splice variants c-FLIP(long) (c-FLIP(L)) and c-FLIP(short) (c-FLIP(S)), which can have opposing functions. We observed diminished expression of the c-FLIP(L) isoform in urothelial carcinoma tissues as well as in established carcinoma cell lines compared with normal urothelial tissues and cells, whereas c-FLIP(S) was unchanged. Overexpression and RNA interference studies in urothelial cell lines nevertheless demonstrated that c-FLIP remained a crucial factor conferring resistance towards induction of apoptosis by death ligands CD95L and TRAIL. Isoform-specific RNA interference showed c-FLIP(L) to be of particular importance. Thus, urothelial carcinoma cells appear to fine-tune c-FLIP expression to a level sufficient for protection against activation of apoptosis by the extrinsic pathway. Therefore, targeting c-FLIP, and especially the c-FLIP(L) isoform, may facilitate apoptosis-based therapies of bladder cancer in otherwise resistant tumours.
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Affiliation(s)
- F Ewald
- Laboratory of Systems-oriented Immunology and Inflammation Research, Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg and Department of Immune Control, Helmholtz Centre for Infection Research, Inhoffenstr 7, D-38124 Braunschweig, Germany
| | - N Ueffing
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University, Universitaetsstr 1, D-40225 Duesseldorf, Germany
| | - L Brockmann
- Institute of Medical Microbiology and Hospital Hygiene, Heinrich-Heine-University, Universitaetsstr 1, D-40225 Duesseldorf, Germany
| | - C Hader
- Department of Urology, Heinrich Heine University, D-40225 Duesseldorf, Germany
| | - T Telieps
- Laboratory of Systems-oriented Immunology and Inflammation Research, Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg and Department of Immune Control, Helmholtz Centre for Infection Research, Inhoffenstr 7, D-38124 Braunschweig, Germany
| | - M Schuster
- Laboratory of Systems-oriented Immunology and Inflammation Research, Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg and Department of Immune Control, Helmholtz Centre for Infection Research, Inhoffenstr 7, D-38124 Braunschweig, Germany
| | - W A Schulz
- Department of Urology, Heinrich Heine University, D-40225 Duesseldorf, Germany
| | - I Schmitz
- Laboratory of Systems-oriented Immunology and Inflammation Research, Institute of Molecular and Clinical Immunology, Otto-von-Guericke-University Magdeburg and Department of Immune Control, Helmholtz Centre for Infection Research, Inhoffenstr 7, D-38124 Braunschweig, Germany
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Kaposi's sarcoma-associated herpesvirus latency-associated nuclear antigen induction by hypoxia and hypoxia-inducible factors. J Virol 2011; 86:1097-108. [PMID: 22090111 DOI: 10.1128/jvi.05167-11] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hypoxia and hypoxia-inducible factors (HIFs) play an important role in the Kaposi's sarcoma-associated herpesvirus (KSHV) life cycle. In particular, hypoxia can activate lytic replication of KSHV and specific lytic genes, including the replication and transcription activator (RTA), while KSHV infection in turn can increase the levels and activity of HIFs. In the present study, we show that hypoxia increases the levels of mRNAs encoding KSHV latency-associated nuclear antigen (LANA) in primary effusion lymphoma (PEL) cell lines and also increases the levels of LANA protein. Luciferase reporter assays in Hep3B cells revealed a moderate activation of the LANA promoter region by hypoxia as well as by cotransfection with degradation-resistant HIF-1α or HIF-2α expression plasmids. Computer analysis of a 1.2-kb sequence upstream of the LANA translational start site identified six potential hypoxia-responsive elements (HRE). Sequential deletion studies revealed that much of this activity was mediated by one of these HREs (HRE 4R) oriented in the 3' to 5' direction and located between the constitutive (LTc) and RTA-inducible (LTi) mRNA start sites. Site-directed mutation of this HRE substantially reduced the response to both HIF-1α and HIF-2α in a luciferase reporter assay. Electrophoretic mobility shift assays (EMSA) and chromatin immunoprecipitation (ChIP) assays demonstrated binding of both HIF-1α and HIF-2α to this region. Also, HIF-1α was found to associate with RTA, and HIFs enhanced the activation of LTi by RTA. These results provide evidence that hypoxia and HIFs upregulate both latent and lytic KSHV replication and play a central role in the life cycle of this virus.
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Abstract
Natural killer (NK) cells and dendritic cells (DCs) are essential effector cells of the innate immune system that rapidly recognize and eliminate microbial pathogens and abnormal cells, and induce and regulate adaptive immune functions. While NK cells express perforin and granzymes in the lysosomal granules and transmembrane tumor necrosis factor superfamily ligands (tmTNFSFL) on the plasma membrane, DCs express only tmTNFSFL on the plasma membrane. Perforin and granzymes are cytolytic molecules, which NK cells use to mediate a secretory/necrotic killing mechanism against rare leukemia cell targets. TNFSFL are pleiotropic transmembrane molecules, which can mediate a variety of important functions such as apoptosis, development of peripheral lymphoid tissues, inflammation and regulation of immune functions. Using tmTNFSFL, NK cells and DCs mediate a cell contact-dependent non-secretory apoptotic cytotoxic mechanism against virtually all types of cancer cells, and cross talk that leads to polarization and reciprocal stimulation and amplification of Th1 type cytokines secreted by NK cells and DCs. In this paper, we review and discuss the supporting evidence of the non-secretory, tmTNFSFL-mediated innate mechanisms of NK cells and DCs, their roles in anticancer immune defense and potential of their modulation and use in prevention and treatment of cancer.
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Cesarman E. Gammaherpesvirus and lymphoproliferative disorders in immunocompromised patients. Cancer Lett 2011; 305:163-74. [PMID: 21493001 PMCID: PMC3742547 DOI: 10.1016/j.canlet.2011.03.003] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 03/04/2011] [Accepted: 03/08/2011] [Indexed: 12/12/2022]
Abstract
Two lymphotropic human gamma herpesviruses can cause lymphoproliferative disorders: Epstein Barr virus (EBV, formally designated as human herpesvirus 4) and Kaposi sarcoma herpesvirus (KSHV, also called human herpesvirus 8). Individuals with inherited or acquired immunodeficiency have a greatly increased risk of developing a malignancy caused by one of these two viruses. Specific types of lymphoproliferations, including malignant lymphomas, occur in individuals with HIV infection, transplant recipients and children with primary immunodeficiency. Some of these diseases, such as Hodgkin's and non-Hodgkin lymphoma resemble those occurring in immunocompetent patients, but the proportion of tumors in which EBV is present is increased. Others, like primary effusion lymphoma and polymorphic post-transplant lymphoproliferative disorder are rarely seen outside the context of a specific immunodeficient state. Understanding the specific viral associations in selected lymphoproliferative disorders, and the insights into the molecular mechanisms of viral oncogenesis, will lead to better treatments for these frequently devastating diseases.
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Affiliation(s)
- Ethel Cesarman
- Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA.
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Defee MR, Qin Z, Dai L, Isaacs JS, Parsons CH. Interactions between Hsp90 and oncogenic viruses: implications for viral cancer therapeutics. Am J Cancer Res 2011; 1:763-772. [PMID: 22016826 PMCID: PMC3195933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 05/31/2011] [Indexed: 05/31/2023] Open
Abstract
Oncogenic viruses are the etiologic agents for a significant proportion of human cancers, but effective therapies and preventative strategies are lacking for the majority of virus-associated cancers. Targeting of virus-induced signal transduction or virus-host protein interactions may offer novel therapeutic strategies for viral cancers. Heat shock protein 90 (Hsp90) is a well-characterized, multifunctional molecular chaperone involved in regulation of signal transduction, transcriptional activation, oncogenic protein stabilization, and neovascularization-pathogenic elements relevant to viral cancer pathogenesis. This review will summarize mechanistic concepts involving regulation of viral oncogenesis by both intracellular and extracellular Hsp90, as well as current therapeutic implications of these data.
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Piersma SJ. Immunosuppressive tumor microenvironment in cervical cancer patients. CANCER MICROENVIRONMENT 2011; 4:361-75. [PMID: 21626415 DOI: 10.1007/s12307-011-0066-7] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2010] [Accepted: 05/18/2011] [Indexed: 12/31/2022]
Abstract
Cervical cancer is caused by Human papillomavirus (HPV) in virtually all cases. These HPV-induced cancers express the viral oncogenes E6 and E7 and are therefore potentially recognized by the immune system. Despite the abundant presence of these foreign antigens, the immune system is unable to cope with the tumor. Due to the constant immunological pressure, cervical cancers can evolve different immune evasion strategies, which will be described in the current review. Several approaches for immunotherapy of cervical cancer are currently under development, which aim at inducing strong HPV-specific immunity. Besides the reinforcement of potent anti-tumor immune responses, immunotherapy could also enhance HPV-specific T regulatory cells. Supplementary strategies that neutralize an immunosuppressive milieu may have great potential. These strategies are discussed as well.
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Affiliation(s)
- Sytse J Piersma
- Department of Medical Microbiology, University Medical Center Utrecht, room G02.667, Huispost G04.614 Heidelberglaan 100, 3584 CX, Utrecht, the Netherlands,
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