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Pedersen EA, Verhaegen ME, Joseph MK, Harms KL, Harms PW. Merkel cell carcinoma: updates in tumor biology, emerging therapies, and preclinical models. Front Oncol 2024; 14:1413793. [PMID: 39136002 PMCID: PMC11317257 DOI: 10.3389/fonc.2024.1413793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2024] [Accepted: 07/08/2024] [Indexed: 08/15/2024] Open
Abstract
Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma thought to arise via either viral (Merkel cell polyomavirus) or ultraviolet-associated pathways. Surgery and radiotherapy have historically been mainstays of management, and immunotherapy has improved outcomes for advanced disease. However, there remains a lack of effective therapy for those patients who fail to respond to these established approaches, underscoring a critical need to better understand MCC biology for more effective prognosis and treatment. Here, we review the fundamental aspects of MCC biology and the recent advances which have had profound impact on management. The first genetically-engineered mouse models for MCC tumorigenesis provide opportunities to understand the potential MCC cell of origin and may prove useful for preclinical investigation of novel therapeutics. The MCC cell of origin debate has also been advanced by recent observations of MCC arising in association with a clonally related hair follicle tumor or squamous cell carcinoma in situ. These studies also suggested a role for epigenetics in the origin of MCC, highlighting a potential utility for this therapeutic avenue in MCC. These and other therapeutic targets form the basis for a wealth of ongoing clinical trials to improve MCC management. Here, we review these recent advances in the context of the existing literature and implications for future investigations.
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Affiliation(s)
| | | | - Mallory K. Joseph
- Department of Dermatology, University of Michigan, Ann Arbor, MI, United States
| | - Kelly L. Harms
- Department of Dermatology, University of Michigan, Ann Arbor, MI, United States
| | - Paul W. Harms
- Department of Dermatology, University of Michigan, Ann Arbor, MI, United States
- Department of Pathology, University of Michigan, Ann Arbor, MI, United States
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Bahar F, DeCaprio JA. Why do we distinguish between virus-positive and virus-negative Merkel cell carcinoma? Br J Dermatol 2024; 190:785-786. [PMID: 38391034 DOI: 10.1093/bjd/ljae086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 01/18/2024] [Indexed: 02/24/2024]
Affiliation(s)
- Furkan Bahar
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - James A DeCaprio
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
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3
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Cross EM, Akbari N, Ghassabian H, Hoad M, Pavan S, Ariawan D, Donnelly CM, Lavezzo E, Petersen GF, Forwood JK, Alvisi G. A functional and structural comparative analysis of large tumor antigens reveals evolution of different importin α-dependent nuclear localization signals. Protein Sci 2024; 33:e4876. [PMID: 38108201 PMCID: PMC10807245 DOI: 10.1002/pro.4876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 12/12/2023] [Accepted: 12/13/2023] [Indexed: 12/19/2023]
Abstract
Nucleocytoplasmic transport regulates the passage of proteins between the nucleus and cytoplasm. In the best characterized pathway, importin (IMP) α bridges cargoes bearing basic, classical nuclear localization signals (cNLSs) to IMPβ1, which mediates transport through the nuclear pore complex. IMPα recognizes three types of cNLSs via two binding sites: the major binding site accommodates monopartite cNLSs, the minor binding site recognizes atypical cNLSs, while bipartite cNLSs simultaneously interact with both major and minor sites. Despite the growing knowledge regarding IMPα-cNLS interactions, our understanding of the evolution of cNLSs is limited. We combined bioinformatic, biochemical, functional, and structural approaches to study this phenomenon, using polyomaviruses (PyVs) large tumor antigens (LTAs) as a model. We characterized functional cNLSs from all human (H)PyV LTAs, located between the LXCXE motif and origin binding domain. Surprisingly, the prototypical SV40 monopartite NLS is not well conserved; HPyV LTA NLSs are extremely heterogenous in terms of structural organization, IMPα isoform binding, and nuclear targeting abilities, thus influencing the nuclear accumulation properties of full-length proteins. While several LTAs possess bipartite cNLSs, merkel cell PyV contains a hybrid bipartite cNLS whose upstream stretch of basic amino acids can function as an atypical cNLS, specifically binding to the IMPα minor site upon deletion of the downstream amino acids after viral integration in the host genome. Therefore, duplication of a monopartite cNLS and subsequent accumulation of point mutations, optimizing interaction with distinct IMPα binding sites, led to the evolution of bipartite and atypical NLSs binding at the minor site.
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Affiliation(s)
- Emily M. Cross
- School of Dentistry and Medical SciencesCharles Sturt UniversityWagga WaggaAustralia
- Diamond Light SourceHarwell Science and Innovation CampusDidcotUnited Kingdom
| | - Nasim Akbari
- Department of Molecular MedicineUniversity of PadovaPadovaItaly
| | | | - Mikayla Hoad
- School of Dentistry and Medical SciencesCharles Sturt UniversityWagga WaggaAustralia
| | - Silvia Pavan
- Department of Molecular MedicineUniversity of PadovaPadovaItaly
| | - Daryl Ariawan
- Dementia Research CentreMacquarie UniversitySydneyAustralia
| | - Camilla M. Donnelly
- School of Dentistry and Medical SciencesCharles Sturt UniversityWagga WaggaAustralia
| | - Enrico Lavezzo
- Department of Molecular MedicineUniversity of PadovaPadovaItaly
| | | | - Jade K. Forwood
- School of Dentistry and Medical SciencesCharles Sturt UniversityWagga WaggaAustralia
- Gulbali InstituteCharles Sturt UniversityWagga WaggaAustralia
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Durand MA, Drouin A, Mouchard A, Durand L, Esnault C, Berthon P, Tallet A, Le Corre Y, Hainaut-Wierzbicka E, Blom A, Saiag P, Beneton N, Bens G, Nardin C, Aubin F, Dinulescu M, Collin C, Fromont-Hankard G, Cribier B, Laurent-Roussel S, Cokelaere K, Houben R, Schrama D, Peixoto P, Hervouet E, Bachiri K, Kantar D, Coyaud E, Guyétant S, Samimi M, Touzé A, Kervarrec T. Distinct Regulation of EZH2 and its Repressive H3K27me3 Mark in Polyomavirus-Positive and -Negative Merkel Cell Carcinoma. J Invest Dermatol 2023; 143:1937-1946.e7. [PMID: 37037414 DOI: 10.1016/j.jid.2023.02.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 02/15/2023] [Accepted: 02/17/2023] [Indexed: 04/12/2023]
Abstract
Merkel cell carcinoma (MCC) is an aggressive skin cancer for which Merkel cell polyomavirus integration and expression of viral oncogenes small T and Large T have been identified as major oncogenic determinants. Recently, a component of the PRC2 complex, the histone methyltransferase enhancer of zeste homolog 2 (EZH2) that induces H3K27 trimethylation as a repressive mark has been proposed as a potential therapeutic target in MCC. Because divergent results have been reported for the levels of EZH2 and trimethylation of lysine 27 on histone 3, we analyzed these factors in a large MCC cohort to identify the molecular determinants of EZH2 activity in MCC and to establish MCC cell lines' sensitivity to EZH2 inhibitors. Immunohistochemical expression of EZH2 was observed in 92% of MCC tumors (156 of 170), with higher expression levels in virus-positive than virus-negative tumors (P = 0.026). For the latter, we showed overexpression of EZHIP, a negative regulator of the PRC2 complex. In vitro, ectopic expression of the large T antigen in fibroblasts led to the induction of EZH2 expression, whereas the knockdown of T antigens in MCC cell lines resulted in decreased EZH2 expression. EZH2 inhibition led to selective cytotoxicity on virus-positive MCC cell lines. This study highlights the distinct mechanisms of EZH2 induction between virus-negative and -positive MCC.
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Affiliation(s)
- Marie-Alice Durand
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France
| | - Aurélie Drouin
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France
| | - Alice Mouchard
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France; Department of Dermatology, CHRU of Tours, University of Tours, Chambray-lès-Tours, France
| | - Laurine Durand
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France
| | - Clara Esnault
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France
| | - Patricia Berthon
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France
| | - Anne Tallet
- Platform of Somatic Tumor Molecular Genetics, CHU of Tours, University of Tours, Tours, France
| | - Yannick Le Corre
- Dermatology Department, CHU of Angers, LUNAM University, Angers, France
| | | | - Astrid Blom
- Department of General and Oncologic Dermatology, Ambroise-Paré Hospital, CARADERM Network, Boulogne-Billancourt, France; Research unit EA 4340, University of Versailles-Saint-Quentin-en-Yvelines, Paris-Saclay University, Boulogne-Billancourt, France
| | - Philippe Saiag
- Department of General and Oncologic Dermatology, Ambroise-Paré Hospital, CARADERM Network, Boulogne-Billancourt, France; Research unit EA 4340, University of Versailles-Saint-Quentin-en-Yvelines, Paris-Saclay University, Boulogne-Billancourt, France
| | - Nathalie Beneton
- Dermatology Department, CHU of Le Mans, University of Le Mans, Le Mans, France
| | - Guido Bens
- Dermatology department, CHR Orleans, Orleans, France
| | - Charlee Nardin
- Dermatology, CHU Besançon, Besançon, France; INSERM 1098, Université Bourgogne Franche-Comté, Besançon, France
| | - François Aubin
- Dermatology, CHU Besançon, Besançon, France; INSERM 1098, Université Bourgogne Franche-Comté, Besançon, France
| | - Monica Dinulescu
- Dermatology department, CHU Rennes, Institut Dermatologique du Grand Ouest (IDGO), Rennes, France
| | - Christine Collin
- Platform of Somatic Tumor Molecular Genetics, CHU of Tours, University of Tours, Tours, France
| | | | - Bernard Cribier
- Dermatology Department, CHU of Strasbourg, University of Strasbourg, Strasbourg, France
| | | | | | - Roland Houben
- Department of Dermatology, Venerology and Allergology, University Hospital of Würzburg, Würzburg, Germany
| | - David Schrama
- Department of Dermatology, Venerology and Allergology, University Hospital of Würzburg, Würzburg, Germany
| | - Paul Peixoto
- INSERM, EFS-BFC, UMR 1098 RIGHT, University Bourgogne-Franche-Comté, Besançon, France; EPIgenetics and GENe Expression Technical Platform (EPIGENExp), University Bourgogne Franche-Comté, Besançon, France
| | - Eric Hervouet
- INSERM, EFS-BFC, UMR 1098 RIGHT, University Bourgogne-Franche-Comté, Besançon, France; EPIgenetics and GENe Expression Technical Platform (EPIGENExp), University Bourgogne Franche-Comté, Besançon, France
| | - Kamel Bachiri
- Department of Biology, Inserm U1192, Protéomique Réponse Inflammatoire Spectrométrie de Masse-PRISM, CHU Lille, Université de Lille, Lille, France
| | - Diala Kantar
- Department of Biology, Inserm U1192, Protéomique Réponse Inflammatoire Spectrométrie de Masse-PRISM, CHU Lille, Université de Lille, Lille, France
| | - Etienne Coyaud
- Department of Biology, Inserm U1192, Protéomique Réponse Inflammatoire Spectrométrie de Masse-PRISM, CHU Lille, Université de Lille, Lille, France
| | - Serge Guyétant
- Pathology Department, CHU of Tours, University of Tours, Tours, France; Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France
| | - Mahtab Samimi
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France; Department of Dermatology, CHRU of Tours, University of Tours, Chambray-lès-Tours, France
| | - Antoine Touzé
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France
| | - Thibault Kervarrec
- Team "Biologie des Infections à Polyomavirus", ISP UMR 1282, INRAE, University of Tours, Tours, France; Pathology Department, CHU of Tours, University of Tours, Tours, France.
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Merkel Cell Polyomavirus Large T Antigen Induces Cellular Senescence for Host Growth Arrest and Viral Genome Persistence through Its Unique Domain. Cells 2023; 12:cells12030380. [PMID: 36766726 PMCID: PMC9913222 DOI: 10.3390/cells12030380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 01/13/2023] [Accepted: 01/17/2023] [Indexed: 01/24/2023] Open
Abstract
Senescent cells accumulate in the host during the aging process and are associated with age-related pathogeneses, including cancer. Although persistent senescence seems to contribute to many aspects of cellular pathways and homeostasis, the role of senescence in virus-induced human cancer is not well understood. Merkel cell carcinoma (MCC) is an aggressive skin cancer induced by a life-long human infection of Merkel cell polyomavirus (MCPyV). Here, we show that MCPyV large T (LT) antigen expression in human skin fibroblasts causes a novel nucleolar stress response, followed by p21-dependent senescence and senescence-associated secretory phenotypes (SASPs), which are required for MCPyV genome maintenance. Senolytic and navitoclax treatments result in decreased senescence and MCPyV genome levels, suggesting a potential therapeutic for MCC prevention. Our results uncover the mechanism of a host stress response regulating human polyomavirus genome maintenance in viral persistency, which may lead to targeted intervention for MCC.
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Merkel Cell Polyomavirus: Infection, Genome, Transcripts and Its Role in Development of Merkel Cell Carcinoma. Cancers (Basel) 2023; 15:cancers15020444. [PMID: 36672392 PMCID: PMC9857234 DOI: 10.3390/cancers15020444] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 12/23/2022] [Accepted: 12/27/2022] [Indexed: 01/13/2023] Open
Abstract
The best characterized polyomavirus family member, i.e., simian virus 40 (SV40), can cause different tumors in hamsters and can transform murine and human cells in vitro. Hence, the SV40 contamination of millions of polio vaccine doses administered from 1955-1963 raised fears that this may cause increased tumor incidence in the vaccinated population. This is, however, not the case. Indeed, up to now, the only polyomavirus family member known to be the most important cause of a specific human tumor entity is Merkel cell polyomavirus (MCPyV) in Merkel cell carcinoma (MCC). MCC is a highly deadly form of skin cancer for which the cellular origin is still uncertain, and which appears as two clinically very similar but molecularly highly different variants. While approximately 80% of cases are found to be associated with MCPyV the remaining MCCs carry a high mutational load. Here, we present an overview of the multitude of molecular functions described for the MCPyV encoded oncoproteins and non-coding RNAs, present the available MCC mouse models and discuss the increasing evidence that both, virus-negative and -positive MCC constitute epithelial tumors.
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Dunowska M, Perrott M, Biggs P. Identification of a novel polyomavirus from a marsupial host. Virus Evol 2022; 8:veac096. [PMID: 36381233 PMCID: PMC9662318 DOI: 10.1093/ve/veac096] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 09/09/2022] [Accepted: 10/05/2022] [Indexed: 08/26/2023] Open
Abstract
We report the identification and analysis of a full sequence of a novel polyomavirus from a brushtail possum (Trichosurus vulpecula ) termed possum polyomavirus (PPyV). The sequence was obtained from the next-generation sequencing assembly during an investigation into the aetiological agent for a neurological disease of possums termed wobbly possum disease (WPD), but the virus was not aetiologically involved in WPD. The PPyV genome was 5,224 nt long with the organisation typical for polyomaviruses, including early (large and small T antigens) and late (Viral Protein 1 (VP1), VP2, and VP3) coding regions separated by the non-coding control region of 465 nt. PPyV clustered with betapolyomaviruses in the WUKI clade but showed less than 60 per cent identity to any of the members of this clade. We propose that PPyV is classified within a new species in the genus Betapolyomavirus . These data add to our limited knowledge of marsupial viruses and their evolution.
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Affiliation(s)
- Magdalena Dunowska
- School of Veterinary Science, Massey University, Palmerston North 4410, New Zealand
| | - Matthew Perrott
- School of Veterinary Science, Massey University, Palmerston North 4410, New Zealand
| | - Patrick Biggs
- School of Veterinary Science, Massey University, Palmerston North 4410, New Zealand
- School of Natural Sciences, Massey University, Palmerston North 4410, New Zealand
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Temblador A, Topalis D, Andrei G, Snoeck R. Synergistic targeting of the PI3K/mTOR and MAPK/ERK pathways in Merkel cell carcinoma. Tumour Virus Res 2022; 14:200244. [PMID: 36007768 PMCID: PMC9449649 DOI: 10.1016/j.tvr.2022.200244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/27/2022] [Accepted: 08/08/2022] [Indexed: 01/13/2023] Open
Abstract
Merkel cell carcinoma (MCC) is an aggressive type of skin cancer, which is caused either by integration of the oncogenic Merkel cell polyomavirus (MCPyV) or by accumulation of UV-light induced mutations. Since the response to immune-checkpoint inhibitors is limited, new therapeutic agents need to be explored. Previous studies have shown that MCC cell lines and xenografts are sensitive to MLN0128, a dual mTOR1/2 inhibitor. Prompted by these results and considering that the PI3K/mTOR and MAPK/ERK pathways are the most commonly deregulated pathways in cancer, the combination of MLN0128 with the MEK1/2 inhibitor trametinib was investigated. Importantly, the combined targeting showed to be synergistic in MCC cell lines and induced alterations in the protein levels of downstream elements of the targeted pathways. This synergistic activity implies a reduction in the dose of each inhibitor necessary to reach the same effect that when used as single agents. Therefore, this is a promising approach to improve the clinical management of MCC and to overcome the limited efficacy of single drug regimens owed to the appearance of toxicity or drug resistance.
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Affiliation(s)
- Arturo Temblador
- Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, KU Leuven, 3000, Leuven, Belgium
| | - Dimitrios Topalis
- Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, KU Leuven, 3000, Leuven, Belgium
| | - Graciela Andrei
- Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, KU Leuven, 3000, Leuven, Belgium,Corresponding author. Rega Institute For Medical Research, Herestraat 49, postbus 1030, 3000, Leuven, Belgium.
| | - Robert Snoeck
- Rega Institute for Medical Research, Department of Microbiology, Immunology and Transplantation, Laboratory of Virology and Chemotherapy, KU Leuven, 3000, Leuven, Belgium
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Ananthapadmanabhan V, Frost TC, Soroko KM, Knott A, Magliozzi BJ, Gokhale PC, Tirunagaru VG, Doebele RC, DeCaprio JA. Milademetan is a highly potent MDM2 inhibitor in Merkel cell carcinoma. JCI Insight 2022; 7:e160513. [PMID: 35801592 PMCID: PMC9310528 DOI: 10.1172/jci.insight.160513] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 06/03/2022] [Indexed: 01/13/2023] Open
Abstract
Merkel cell carcinoma (MCC) is an aggressive neuroendocrine carcinoma of the skin with 2 etiologies. Merkel cell polyomavirus (MCPyV) integration is present in about 80% of all MCC. Virus-positive MCC (MCCP) tumors have few somatic mutations and usually express WT p53 (TP53). By contrast, virus-negative MCC (MCCN) tumors present with a high tumor mutational burden and predominantly UV mutational signature. MCCN tumors typically contain mutated TP53. MCCP tumors express 2 viral proteins: MCPyV small T antigen and a truncated form of large T antigen. MCPyV ST specifically activates expression of MDM2, an E3 ubiquitin ligase of p53, to inhibit p53-mediated tumor suppression. In this study, we assessed the efficacy of milademetan, a potent, selective, and orally available MDM2 inhibitor in several MCC models. Milademetan reduced cell viability of WT p53 MCC cell lines and triggered a rapid and sustained p53 response. Milademetan showed a dose-dependent inhibition of tumor growth in MKL-1 xenograft and patient-derived xenograft models. Here, along with preclinical data for the efficacy of milademetan in WT p53 MCC tumors, we report several in vitro and in vivo models useful for future MCC studies.
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Affiliation(s)
- Varsha Ananthapadmanabhan
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Thomas C. Frost
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Program in Virology, Graduate School of Arts and Sciences, Harvard University, Cambridge, Massachusetts, USA
| | - Kara M. Soroko
- Experimental Therapeutics Core at Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Aine Knott
- Experimental Therapeutics Core at Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Brianna J. Magliozzi
- Experimental Therapeutics Core at Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | - Prafulla C. Gokhale
- Experimental Therapeutics Core at Dana-Farber Cancer Institute, Boston, Massachusetts, USA
| | | | | | - James A. DeCaprio
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA
- Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, USA
- Program in Virology, Graduate School of Arts and Sciences, Harvard University, Cambridge, Massachusetts, USA
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Spurgeon ME, Cheng J, Ward-Shaw E, Dick FA, DeCaprio JA, Lambert PF. Merkel cell polyomavirus large T antigen binding to pRb promotes skin hyperplasia and tumor development. PLoS Pathog 2022; 18:e1010551. [PMID: 35560034 PMCID: PMC9132321 DOI: 10.1371/journal.ppat.1010551] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 05/25/2022] [Accepted: 04/26/2022] [Indexed: 12/14/2022] Open
Abstract
Clear evidence supports a causal link between Merkel cell polyomavirus (MCPyV) and the highly aggressive human skin cancer called Merkel cell carcinoma (MCC). Integration of viral DNA into the human genome facilitates continued expression of the MCPyV small tumor (ST) and large tumor (LT) antigens in virus-positive MCCs. In MCC tumors, MCPyV LT is truncated in a manner that renders the virus unable to replicate yet preserves the LXCXE motif that facilitates its binding to and inactivation of the retinoblastoma tumor suppressor protein (pRb). We previously developed a MCPyV transgenic mouse model in which MCC tumor-derived ST and truncated LT expression were targeted to the stratified epithelium of the skin, causing epithelial hyperplasia, increased proliferation, and spontaneous tumorigenesis. We sought to determine if any of these phenotypes required the association between the truncated MCPyV LT and pRb. Mice were generated in which K14-driven MCPyV ST/LT were expressed in the context of a homozygous RbΔLXCXE knock-in allele that attenuates LT-pRb interactions through LT's LXCXE motif. We found that many of the phenotypes including tumorigenesis that develop in the K14-driven MCPyV transgenic mice were dependent upon LT's LXCXE-dependent interaction with pRb. These findings highlight the importance of the MCPyV LT-pRb interaction in an in vivo model for MCPyV-induced tumorigenesis.
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Affiliation(s)
- Megan E. Spurgeon
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
- * E-mail:
| | - Jingwei Cheng
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, New Hampshire, United States of America
| | - Ella Ward-Shaw
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
| | - Frederick A. Dick
- Department of Pathology and Laboratory Medicine, Western University, London, Ontario, Canada
- Children’s Health Research Institute, London, Ontario, Canada
- London Regional Cancer Program, London Health Sciences Centre, London, Ontario, Canada
| | - James A. DeCaprio
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, United States of America
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Paul F. Lambert
- McArdle Laboratory for Cancer Research, Department of Oncology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States of America
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Investigation of the RB1-SOX2 axis constitutes a tool for viral status determination and diagnosis in Merkel cell carcinoma. Virchows Arch 2022; 480:1239-1254. [PMID: 35412101 DOI: 10.1007/s00428-022-03315-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 12/30/2022]
Abstract
MCC (Merkel cell carcinoma) is an aggressive neuroendocrine cutaneous neoplasm. Integration of the Merkel cell polyomavirus (MCPyV) is observed in about 80% of the cases, while the remaining 20% are related to UV exposure. Both MCPyV-positive and -negative MCCs-albeit by different mechanisms-are associated with RB1 inactivation leading to overexpression of SOX2, a major contributor to MCC biology. Moreover, although controversial, loss of RB1 expression seems to be restricted to MCPyV-negative cases.The aim of the present study was to assess the performances of RB1 loss and SOX2 expression detected by immunohistochemistry to determine MCPyV status and to diagnose MCC, respectively.Overall, 196 MCC tumors, 233 non-neuroendocrine skin neoplasms and 70 extra-cutaneous neuroendocrine carcinomas (NEC) were included. SOX2 and RB1 expressions were assessed by immunohistochemistry in a tissue micro-array. Diagnostic performances were determined using the likelihood ratio (LHR).RB1 expression loss was evidenced in 27% of the MCC cases, 12% of non-neuroendocrine skin tumors and 63% of extra-cutaneous NEC. Importantly, among MCC cases, RB1 loss was detected in all MCPyV(-) MCCs, while MCPyV( +) cases were consistently RB1-positive (p < 0.001). SOX2 diffuse expression was observed in 92% of the MCC cases and almost never observed in non-neuroendocrine skin epithelial neoplasms (2%, p < 0.0001, LHR + = 59). Furthermore, SOX2 diffuse staining was more frequently observed in MCCs than in extra-cutaneous NECs (30%, p < 0.001, LHR + = 3.1).These results confirm RB1 as a robust predictor of MCC viral status and further suggest SOX2 to be a relevant diagnostic marker of MCC.
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Temblador A, Topalis D, van den Oord J, Andrei G, Snoeck R. Organotypic Epithelial Raft Cultures as a Three-Dimensional In Vitro Model of Merkel Cell Carcinoma. Cancers (Basel) 2022; 14:cancers14041091. [PMID: 35205840 PMCID: PMC8870341 DOI: 10.3390/cancers14041091] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/03/2022] [Accepted: 02/14/2022] [Indexed: 01/27/2023] Open
Abstract
Merkel cell carcinoma (MCC) is a rare type of skin cancer for which an in vitro model is still lacking. MCC tumorigenesis is associated either with the integration of Merkel cell polyomavirus into the host genome, or with the accumulation of somatic mutations upon chronic exposure to UV light. Transgenic animals expressing the viral oncoproteins, which are constitutively expressed in virus-related MCC, do not fully recapitulate MCC. Although cell-line-derived xenografts have been established for the two subtypes of MCC, they still present certain limitations. Here, we generated organotypic epithelial raft cultures (OERCs) of MCC by using primary human keratinocytes and both virus-positive and virus-negative MCC cell lines. The primary human keratinocytes and the tumor cells were grown on top of a dermal equivalent. Histological and immunohistochemical examination of the rafts confirmed the growth of MCC cells. Furthermore, gene expression analysis revealed differences in the expression profiles of the distinct tumor cells and the keratinocytes at the transcriptional level. In summary, considering the limited availability of patient samples, OERCs of MCC may constitute a suitable model for evaluating the efficacy and selectivity of new drug candidates against MCC; moreover, they are a potential tool to study the oncogenic mechanisms of this malignancy.
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Affiliation(s)
- Arturo Temblador
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium; (A.T.); (D.T.); (R.S.)
| | - Dimitrios Topalis
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium; (A.T.); (D.T.); (R.S.)
| | - Joost van den Oord
- Laboratory of Translational Cell and Tissue Research, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium;
| | - Graciela Andrei
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium; (A.T.); (D.T.); (R.S.)
- Correspondence:
| | - Robert Snoeck
- Laboratory of Virology and Chemotherapy, Department of Microbiology, Immunology and Transplantation, Rega Institute for Medical Research, KU Leuven, 3000 Leuven, Belgium; (A.T.); (D.T.); (R.S.)
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13
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Inhibition of T-antigen expression promoting glycogen synthase kinase 3 impairs merkel cell carcinoma cell growth. Cancer Lett 2022; 524:259-267. [PMID: 34715251 DOI: 10.1016/j.canlet.2021.10.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 10/08/2021] [Accepted: 10/18/2021] [Indexed: 12/12/2022]
Abstract
Merkel cell carcinoma is an aggressive skin cancer frequently caused by the Merkel cell polyomavirus (MCPyV). Since proliferation of MCPyV-positive MCC tumor cells strictly depends on expression of the virus-encoded T antigens (TA), these proteins theoretically represent ideal targets for different kinds of therapeutic approaches. Here we developed a cell-based assay to identify compounds which specifically inhibit growth of MCC cells by repressing TA expression. Applying this technique we screened a kinase inhibitor library and identified six compounds targeting glycogen synthase kinase 3 (GSK3) such as CHIR99021 as suppressors of TA transcription in MCC cells. Involvement of GSK3α and -β in the regulation of TA-expression was confirmed by combining GSK3A knockout with inducible GSK3B shRNA knockdown since double knockouts could not be generated. Finally, we demonstrate that CHIR99021 exhibits in vivo antitumor activity in an MCC xenograft mouse model suggesting GSK3 inhibitors as potential therapeutics for the treatment of MCC in the future.
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14
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Ahmed MM, Cushman CH, DeCaprio JA. Merkel Cell Polyomavirus: Oncogenesis in a Stable Genome. Viruses 2021; 14:v14010058. [PMID: 35062263 PMCID: PMC8781562 DOI: 10.3390/v14010058] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 12/28/2021] [Accepted: 12/29/2021] [Indexed: 12/14/2022] Open
Abstract
Merkel cell polyomavirus (MCV) is the causative agent for the majority of Merkel cell carcinoma (MCC) cases. Polyomavirus-associated MCC (MCCP) is characterized by the integration of MCV DNA into the tumor genome and a low tumor mutational burden. In contrast, nonviral MCC (MCCN) is characterized by a high tumor mutational burden induced by UV damage. Since the discovery of MCV, much work in the field has focused on understanding the molecular mechanisms of oncogenesis driven by the MCV tumor (T) antigens. Here, we review our current understanding of how the activities of large T (LT) and small T (ST) promote MCC oncogenesis in the absence of genomic instability. We highlight how both LT and ST inhibit tumor suppressors to evade growth suppression, an important cancer hallmark. We discuss ST interactions with cellular proteins, with an emphasis on those that contribute to sustaining proliferative signaling. Finally, we examine active areas of research into open questions in the field, including the origin of MCC and mechanisms of viral integration.
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Affiliation(s)
- Mona M. Ahmed
- Program in Virology, Graduate School of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA; (M.M.A.); (C.H.C.)
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Camille H. Cushman
- Program in Virology, Graduate School of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA; (M.M.A.); (C.H.C.)
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - James A. DeCaprio
- Program in Virology, Graduate School of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA; (M.M.A.); (C.H.C.)
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
- Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Correspondence:
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15
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Gao J, Shi H, Juhlin CC, Larsson C, Lui WO. Merkel cell polyomavirus T-antigens regulate DICER1 mRNA stability and translation through HSC70. iScience 2021; 24:103264. [PMID: 34761184 PMCID: PMC8567380 DOI: 10.1016/j.isci.2021.103264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/13/2021] [Accepted: 10/09/2021] [Indexed: 01/07/2023] Open
Abstract
Merkel cell carcinoma is an aggressive skin malignancy, mostly caused by Merkel cell polyomavirus (MCPyV). MCPyV T-antigens can induce mature microRNA expressions through the DnaJ domain, but its underlying mechanism is still unknown. Here, we report that the T-antigens induce protein expression and mRNA stability of DICER1, a key factor in microRNA biogenesis, through heat shock cognate 70 (HSC70). HSC70 directly interacts with the AU-rich elements (ARE) of DICER1 mRNA in both coding and 3′ untranslated region in the presence of MCPyV T-antigen. The T-antigen/HSC70 interaction could induce luciferase activity of synthetic ARE-containing reporter, as well as the stability of ARE-containing mRNAs, suggesting a broader role of MCPyV T-antigens in regulating multiple mRNAs via HSC70. These findings highlight a new role for the interaction of HSC70 and MCPyV T-antigens in mRNA regulation and an undescribed regulatory mechanism of DICER1 mRNA stability and translation through its direct interaction with HSC70. MCPyV T-antigen and HSC70 interaction regulates DICER1 expression HSC70 directly binds to ARE in the 3′UTR of DICER1 for expression regulation An unknown motif in DICER1 CDS is also required for its expression regulation by LT The LT-HSC70 interaction can regulate other ARE-containing mRNAs
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Affiliation(s)
- Jiwei Gao
- Department of Oncology-Pathology, Karolinska Institutet; BioClinicum, Karolinska University Hospital, 171 64 Solna, Sweden
| | - Hao Shi
- Department of Oncology-Pathology, Karolinska Institutet; BioClinicum, Karolinska University Hospital, 171 64 Solna, Sweden
| | - C Christofer Juhlin
- Department of Oncology-Pathology, Karolinska Institutet; BioClinicum, Karolinska University Hospital, 171 64 Solna, Sweden.,Department of Pathology and Cancer Diagnostics, Karolinska University Hospital, 171 64 Solna, Sweden
| | - Catharina Larsson
- Department of Oncology-Pathology, Karolinska Institutet; BioClinicum, Karolinska University Hospital, 171 64 Solna, Sweden
| | - Weng-Onn Lui
- Department of Oncology-Pathology, Karolinska Institutet; BioClinicum, Karolinska University Hospital, 171 64 Solna, Sweden
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16
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DeCaprio JA. Molecular Pathogenesis of Merkel Cell Carcinoma. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2020; 16:69-91. [PMID: 33228463 DOI: 10.1146/annurev-pathmechdis-012419-032817] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Merkel cell carcinoma (MCC) is an aggressive neuroendocrine carcinoma of the skin with two distinct etiologies. Clonal integration of Merkel cell polyomavirus DNA into the tumor genome with persistent expression of viral T antigens causes at least 60% of all MCC. UV damage leading to highly mutated genomes causes a nonviral form of MCC. Despite these distinct etiologies, both forms of MCC are similar in presentation, prognosis, and response to therapy. At least three oncogenic transcriptional programs feature prominently in both forms of MCC driven by the virus or by mutation. Both forms of MCC have a high proliferative growth rate with increased levels of cell cycle-dependent genes due to inactivation of the tumor suppressors RB and p53, a strong MYC signature due to MYCL activation by the virus or gene amplification, and an attenuated neuroendocrine differentiation program driven by the ATOH1 transcription factor.
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Affiliation(s)
- James A DeCaprio
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215, USA; .,Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.,Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115, USA
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17
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Merkel Cell Polyomavirus Large T Antigen is Dispensable in G2 and M-Phase to Promote Proliferation of Merkel Cell Carcinoma Cells. Viruses 2020; 12:v12101162. [PMID: 33066686 PMCID: PMC7602435 DOI: 10.3390/v12101162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 11/23/2022] Open
Abstract
Merkel cell carcinoma (MCC) is an aggressive skin cancer frequently caused by the Merkel cell polyomavirus (MCPyV), and proliferation of MCPyV-positive MCC tumor cells depends on the expression of a virus-encoded truncated Large T antigen (LT) oncoprotein. Here, we asked in which phases of the cell cycle LT activity is required for MCC cell proliferation. Hence, we generated fusion-proteins of MCPyV-LT and parts of geminin (GMMN) or chromatin licensing and DNA replication factor1 (CDT1). This allowed us to ectopically express an LT, which is degraded either in the G1 or G2 phase of the cell cycle, respectively, in MCC cells with inducible T antigen knockdown. We demonstrate that LT expressed only in G1 is capable of rescuing LT knockdown-induced growth suppression while LT expressed in S and G2/M phases fails to support proliferation of MCC cells. These results suggest that the crucial function of LT, which has been demonstrated to be inactivation of the cellular Retinoblastoma protein 1 (RB1) is only required to initiate S phase entry.
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18
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Genome-wide profiling of BK polyomavirus integration in bladder cancer of kidney transplant recipients reveals mechanisms of the integration at the nucleotide level. Oncogene 2020; 40:46-54. [PMID: 33051598 DOI: 10.1038/s41388-020-01502-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 11/08/2022]
Abstract
Chronic BK polyomavirus (BKPyV) infection is recognized as a potential oncogenic factor of urothelial carcinoma (UC) in renal transplant recipients. Recent studies have reported a positive correlation among BKPyV integration, persistent overexpression of viral large T antigen (TAg), and malignancy, yet little is known about the specific integration mechanisms and the impacts of viral integration. Here, we performed whole-genome sequencing (WGS) and viral capture-based sequencing on high-grade immunohistochemically TAg-positive UCs in two renal transplant recipients. A total of 181 integration sites, including the three found by WGS, were identified by viral capture-based sequencing, indicating its enhanced sensitivity and ability in identifying low-read integration sites in subpopulations of the tumor cells. The microhomologies between human and BKPyV genomes were significantly enriched in the flanking regions of 84.5% the integration sites, with a median length of 7 bp. Notably, 75 human genes formed fusion sequences due to viral insertional integration. Among them, the expression of 15 genes were statistically associated with UC based on GEO2R expression analysis. Our results indicated a multisite and multifragment linear integration pattern and a potential microhomology or nonhomologous end joining integration mechanism at the single-nucleotide level. We put forward a potential selection mechanism driven by immunity and centered on viral integration in the carcinogenesis of BKPyV.
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19
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Merkel Cell Polyomavirus Large T Antigen Unique Domain Regulates Its Own Protein Stability and Cell Growth. Viruses 2020; 12:v12091043. [PMID: 32962090 PMCID: PMC7551350 DOI: 10.3390/v12091043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/14/2020] [Accepted: 09/16/2020] [Indexed: 02/07/2023] Open
Abstract
Merkel cell polyomavirus (MCV) is the only known human oncogenic virus in the polyomaviridae family and the etiological agent of most Merkel cell carcinomas (MCC). MCC is an aggressive and highly metastatic skin cancer with a propensity for recurrence and poor prognosis. Large tumor antigen (LT), is an essential oncoprotein for MCV transcription, viral replication, and cancer cell proliferation. MCV LT is a short-lived protein that encodes a unique domain: MCV LT unique regions (MURs). These domains consist of phosphorylation sites that interact with multiple E3 ligases, thus limiting LT expression and consequently, viral replication. In this study, we show that MURs are necessary for regulating LT stability via multiple E3 ligase interactions, resulting in cell growth arrest. While expression of wild-type MCV LT induced a decrease in cellular proliferation, deletion of the MUR domains resulted in increased LT stability and cell proliferation. Conversely, addition of MURs to SV40 LT propagated E3 ligase interactions, which in turn, reduced SV40 LT stability and decreased cell growth activity. Our results demonstrate that compared to other human polyomaviruses (HPyVs), MCV LT has evolved to acquire the MUR domains that are essential for MCV LT autoregulation, potentially leading to viral latency and MCC.
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20
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Kervarrec T, Samimi M, Hesbacher S, Berthon P, Wobser M, Sallot A, Sarma B, Schweinitzer S, Gandon T, Destrieux C, Pasqualin C, Guyétant S, Touzé A, Houben R, Schrama D. Merkel Cell Polyomavirus T Antigens Induce Merkel Cell-Like Differentiation in GLI1-Expressing Epithelial Cells. Cancers (Basel) 2020; 12:cancers12071989. [PMID: 32708246 PMCID: PMC7409360 DOI: 10.3390/cancers12071989] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 07/13/2020] [Indexed: 12/18/2022] Open
Abstract
Merkel cell carcinoma (MCC) is an aggressive skin cancer frequently caused by the Merkel cell polyomavirus (MCPyV). It is still under discussion, in which cells viral integration and MCC development occurs. Recently, we demonstrated that a virus-positive MCC derived from a trichoblastoma, an epithelial neoplasia bearing Merkel cell (MC) differentiation potential. Accordingly, we hypothesized that MC progenitors may represent an origin of MCPyV-positive MCC. To sustain this hypothesis, phenotypic comparison of trichoblastomas and physiologic human MC progenitors was conducted revealing GLI family zinc finger 1 (GLI1), Keratin 17 (KRT 17), and SRY-box transcription factor 9 (SOX9) expressions in both subsets. Furthermore, GLI1 expression in keratinocytes induced transcription of the MC marker SOX2 supporting a role of GLI1 in human MC differentiation. To assess a possible contribution of the MCPyV T antigens (TA) to the development of an MC-like phenotype, human keratinocytes were transduced with TA. While this led only to induction of KRT8, an early MC marker, combined GLI1 and TA expression gave rise to a more advanced MC phenotype with SOX2, KRT8, and KRT20 expression. Finally, we demonstrated MCPyV-large T antigens’ capacity to inhibit the degradation of the MC master regulator Atonal bHLH transcription factor 1 (ATOH1). In conclusion, our report suggests that MCPyV TA contribute to the acquisition of an MC-like phenotype in epithelial cells.
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Affiliation(s)
- Thibault Kervarrec
- Department of Pathology, Université de Tours, CHU de Tours, Avenue de la République, 37170 Chambray-les-Tours, France;
- “Biologie des Infections à Polyomavirus” Team, UMR INRA ISP 1282, Université de Tours, 31 Avenue Monge, 37200 Tours, France; (M.S.); (P.B.); (T.G.); (A.T.)
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany; (S.H.); (M.W.); (B.S.); (S.S.); (R.H.); (D.S.)
- Correspondence:
| | - Mahtab Samimi
- “Biologie des Infections à Polyomavirus” Team, UMR INRA ISP 1282, Université de Tours, 31 Avenue Monge, 37200 Tours, France; (M.S.); (P.B.); (T.G.); (A.T.)
- Dermatology Department, Université de Tours, CHU de Tours, Avenue de la République, 37170 Chambray-les-Tours, France
| | - Sonja Hesbacher
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany; (S.H.); (M.W.); (B.S.); (S.S.); (R.H.); (D.S.)
| | - Patricia Berthon
- “Biologie des Infections à Polyomavirus” Team, UMR INRA ISP 1282, Université de Tours, 31 Avenue Monge, 37200 Tours, France; (M.S.); (P.B.); (T.G.); (A.T.)
| | - Marion Wobser
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany; (S.H.); (M.W.); (B.S.); (S.S.); (R.H.); (D.S.)
| | - Aurélie Sallot
- Plastic Surgery Department, Université de Tours, CHU de Tours, Avenue de la République, 37170 Chambray-les-Tours, France;
| | - Bhavishya Sarma
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany; (S.H.); (M.W.); (B.S.); (S.S.); (R.H.); (D.S.)
| | - Sophie Schweinitzer
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany; (S.H.); (M.W.); (B.S.); (S.S.); (R.H.); (D.S.)
| | - Théo Gandon
- “Biologie des Infections à Polyomavirus” Team, UMR INRA ISP 1282, Université de Tours, 31 Avenue Monge, 37200 Tours, France; (M.S.); (P.B.); (T.G.); (A.T.)
| | - Christophe Destrieux
- Neurosurgery Department, UMR 1253, i Brain, Université De Tours, CHU de Tours, Boulevard Tonnelé, 37044 Tours, France;
| | - Côme Pasqualin
- CNRS ERL 7368, Signalisation et Transports Ioniques Membranaires, Equipe Transferts Ioniques et Rythmicité Cardiaque, Groupe Physiologie des Cellules Cardiaques et Vasculaires, Université de Tours, 31 Avenue Monge, 37200 Tours, France;
| | - Serge Guyétant
- Department of Pathology, Université de Tours, CHU de Tours, Avenue de la République, 37170 Chambray-les-Tours, France;
- “Biologie des Infections à Polyomavirus” Team, UMR INRA ISP 1282, Université de Tours, 31 Avenue Monge, 37200 Tours, France; (M.S.); (P.B.); (T.G.); (A.T.)
| | - Antoine Touzé
- “Biologie des Infections à Polyomavirus” Team, UMR INRA ISP 1282, Université de Tours, 31 Avenue Monge, 37200 Tours, France; (M.S.); (P.B.); (T.G.); (A.T.)
| | - Roland Houben
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany; (S.H.); (M.W.); (B.S.); (S.S.); (R.H.); (D.S.)
| | - David Schrama
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany; (S.H.); (M.W.); (B.S.); (S.S.); (R.H.); (D.S.)
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21
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Pietropaolo V, Prezioso C, Moens U. Merkel Cell Polyomavirus and Merkel Cell Carcinoma. Cancers (Basel) 2020; 12:E1774. [PMID: 32635198 PMCID: PMC7407210 DOI: 10.3390/cancers12071774] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 12/12/2022] Open
Abstract
Viruses are the cause of approximately 15% of all human cancers. Both RNA and DNA human tumor viruses have been identified, with Merkel cell polyomavirus being the most recent one to be linked to cancer. This virus is associated with about 80% of Merkel cell carcinomas, a rare, but aggressive cutaneous malignancy. Despite its name, the cells of origin of this tumor may not be Merkel cells. This review provides an update on the structure and life cycle, cell tropism and epidemiology of the virus and its oncogenic properties. Putative strategies to prevent viral infection or treat virus-positive Merkel cell carcinoma patients are discussed.
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Affiliation(s)
- Valeria Pietropaolo
- Department of Public Health and Infectious Diseases, “Sapienza” University, 00185 Rome, Italy; (V.P.); (C.P.)
| | - Carla Prezioso
- Department of Public Health and Infectious Diseases, “Sapienza” University, 00185 Rome, Italy; (V.P.); (C.P.)
- IRCSS San Raffaele Pisana, Microbiology of Chronic Neuro-Degenerative Pathologies, 00166 Rome, Italy
| | - Ugo Moens
- Molecular Inflammation Research Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø—The Arctic University of Norway, 9037 Tromsø, Norway
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22
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Tabachnick-Cherny S, Pulliam T, Church C, Koelle DM, Nghiem P. Polyomavirus-driven Merkel cell carcinoma: Prospects for therapeutic vaccine development. Mol Carcinog 2020; 59:807-821. [PMID: 32219902 PMCID: PMC8238237 DOI: 10.1002/mc.23190] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/06/2020] [Accepted: 03/07/2020] [Indexed: 12/15/2022]
Abstract
Great strides have been made in cancer immunotherapy including the breakthrough successes of anti-PD-(L)1 checkpoint inhibitors. In Merkel cell carcinoma (MCC), a rare and aggressive skin cancer, PD-(L)1 blockade is highly effective. Yet, ~50% of patients either do not respond to therapy or develop PD-(L)1 refractory disease and, thus, do not experience long-term benefit. For these patients, additional or combination therapies are needed to augment immune responses that target and eliminate cancer cells. Therapeutic vaccines targeting tumor-associated antigens, mutated self-antigens, or immunogenic viral oncoproteins are currently being developed to augment T-cell responses. Approximately 80% of MCC cases in the United States are driven by the ongoing expression of viral T-antigen (T-Ag) oncoproteins from genomically integrated Merkel cell polyomavirus (MCPyV). Since T-Ag elicits specific B- and T-cell immune responses in most persons with virus-positive MCC (VP-MCC), and ongoing T-Ag expression is required to drive VP-MCC cell proliferation, therapeutic vaccination with T-Ag is a rational potential component of immunotherapy. Failure of the endogenous T-cell response to clear VP-MCC (allowing clinically evident tumors to arise) implies that therapeutic vaccination will need to be potent anśd synergize with other mechanisms to enhance T-cell activity against tumor cells. Here, we review the relevant underlying biology of VP-MCC, potentially applicable therapeutic vaccine platforms, and antigen delivery formats. We also describe early successes in the field of therapeutic cancer vaccines and address several clinical scenarios in which VP-MCC patients could potentially benefit from a therapeutic vaccine.
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Affiliation(s)
- Shira Tabachnick-Cherny
- Department of Medicine, Division of Dermatology, University of Washington, Seattle, Washington
| | - Thomas Pulliam
- Department of Medicine, Division of Dermatology, University of Washington, Seattle, Washington
| | - Candice Church
- Department of Medicine, Division of Dermatology, University of Washington, Seattle, Washington
| | - David M Koelle
- Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington
- Translational Research Program, Benaroya Research Institute at Virginia Mason, Seattle, Washington
- Department of Laboratory Medicine, University of Washington, Seattle, Washington
- Department of Global Health, University of Washington, Seattle, Washington
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Paul Nghiem
- Department of Medicine, Division of Dermatology, University of Washington, Seattle, Washington
- Seattle Cancer Care Alliance, Seattle, Washington
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
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23
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Artesunate Affects T Antigen Expression and Survival of Virus-Positive Merkel Cell Carcinoma. Cancers (Basel) 2020; 12:cancers12040919. [PMID: 32283634 PMCID: PMC7225937 DOI: 10.3390/cancers12040919] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/06/2020] [Accepted: 04/07/2020] [Indexed: 01/01/2023] Open
Abstract
Merkel cell carcinoma (MCC) is a rare and highly aggressive skin cancer with frequent viral etiology. Indeed, in about 80% of cases, there is an association with Merkel cell polyomavirus (MCPyV); the expression of viral T antigens is crucial for growth of virus-positive tumor cells. Since artesunate—a drug used to treat malaria—has been reported to possess additional anti-tumor as well as anti-viral activity, we sought to evaluate pre-clinically the effect of artesunate on MCC. We found that artesunate repressed growth and survival of MCPyV-positive MCC cells in vitro. This effect was accompanied by reduced large T antigen (LT) expression. Notably, however, it was even more efficient than shRNA-mediated downregulation of LT expression. Interestingly, in one MCC cell line (WaGa), T antigen knockdown rendered cells less sensitive to artesunate, while for two other MCC cell lines, we could not substantiate such a relation. Mechanistically, artesunate predominantly induces ferroptosis in MCPyV-positive MCC cells since known ferroptosis-inhibitors like DFO, BAF-A1, Fer-1 and β-mercaptoethanol reduced artesunate-induced death. Finally, application of artesunate in xenotransplanted mice demonstrated that growth of established MCC tumors can be significantly suppressed in vivo. In conclusion, our results revealed a highly anti-proliferative effect of the approved and generally well-tolerated anti-malaria compound artesunate on MCPyV-positive MCC cells, suggesting its potential usage for MCC therapy.
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CRISPR/Cas9 Editing of the Polyomavirus Tumor Antigens Inhibits Merkel Cell Carcinoma Growth In Vitro. Cancers (Basel) 2019; 11:cancers11091260. [PMID: 31466237 PMCID: PMC6770690 DOI: 10.3390/cancers11091260] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/21/2019] [Accepted: 08/24/2019] [Indexed: 12/26/2022] Open
Abstract
Merkel cell carcinoma (MCC) is an aggressive type of skin cancer whose main causative agent is Merkel cell polyomavirus (MCPyV). MCPyV is integrated into the genome of the tumor cells in most MCCs. Virus-positive tumor cells constitutively express two viral oncoproteins that promote cell growth: the small (sT) and the large (LT) tumor antigens (TAs). Despite the success of immunotherapies in patients with MCC, not all individuals respond to these treatments. Therefore, new therapeutic options continue to be investigated. Herein, we used CRISPR/Cas9 to target the viral oncogenes in two virus-positive MCC cell lines: MS-1 and WAGA. Frameshift mutations introduced in the target sequence upon repair of the Cas9-induced DNA break resulted in decreased LT protein levels, which subsequently impaired cell proliferation, caused cell cycle arrest, and led to increased apoptosis. Importantly, a virus-negative non-MCC cell line (HEK293T) remained unaffected, as well as those cells expressing a non-targeting single-guide RNA (sgRNA). Thus, we presumed that the noted effects were not due to the off-target activity of the TAs-targeting sgRNAs. Additionally, WAGA cells had altered levels of cellular proteins involved in cell cycle regulation, supporting the observed cell cycle. Taken together, our findings provide evidence for the development of a CRISPR/Cas9-based therapeutic option for virus-positive MCC.
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Kervarrec T, Samimi M, Guyétant S, Sarma B, Chéret J, Blanchard E, Berthon P, Schrama D, Houben R, Touzé A. Histogenesis of Merkel Cell Carcinoma: A Comprehensive Review. Front Oncol 2019; 9:451. [PMID: 31245285 PMCID: PMC6579919 DOI: 10.3389/fonc.2019.00451] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/13/2019] [Indexed: 12/11/2022] Open
Abstract
Merkel cell carcinoma (MCC) is a primary neuroendocrine carcinoma of the skin. This neoplasia features aggressive behavior, resulting in a 5-year overall survival rate of 40%. In 2008, Feng et al. identified Merkel cell polyomavirus (MCPyV) integration into the host genome as the main event leading to MCC oncogenesis. However, despite identification of this crucial viral oncogenic trigger, the nature of the cell in which MCC oncogenesis occurs is actually unknown. In fact, several hypotheses have been proposed. Despite the large similarity in phenotype features between MCC tumor cells and physiological Merkel cells (MCs), a specialized subpopulation of the epidermis acting as mechanoreceptor of the skin, several points argue against the hypothesis that MCC derives directly from MCs. Alternatively, MCPyV integration could occur in another cell type and induce acquisition of an MC-like phenotype. Accordingly, an epithelial as well as a fibroblastic or B-cell origin of MCC has been proposed mainly based on phenotype similarities shared by MCC and these potential ancestries. The aim of this present review is to provide a comprehensive review of the current knowledge of the histogenesis of MCC.
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Affiliation(s)
- Thibault Kervarrec
- Department of Pathology, Centre Hospitalier Universitaire de Tours, Tours, France.,ISP "Biologie des infections à polyomavirus" team, UMR INRA 1282, University of Tours, Tours, France.,Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Mahtab Samimi
- ISP "Biologie des infections à polyomavirus" team, UMR INRA 1282, University of Tours, Tours, France.,Departement of Dermatology, Centre Hospitalier Universitaire de Tours, Tours, France
| | - Serge Guyétant
- Department of Pathology, Centre Hospitalier Universitaire de Tours, Tours, France.,ISP "Biologie des infections à polyomavirus" team, UMR INRA 1282, University of Tours, Tours, France
| | - Bhavishya Sarma
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Jérémy Chéret
- Monasterium Laboratory, Skin and Hair Research Solutions GmbH, Münster, Germany
| | - Emmanuelle Blanchard
- Department of Pathology, Centre Hospitalier Universitaire de Tours, Tours, France.,Plateforme IBiSA de Microscopie Electronique, INSERM 1259, Université de Tours, Tours, France
| | - Patricia Berthon
- ISP "Biologie des infections à polyomavirus" team, UMR INRA 1282, University of Tours, Tours, France
| | - David Schrama
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Roland Houben
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Antoine Touzé
- ISP "Biologie des infections à polyomavirus" team, UMR INRA 1282, University of Tours, Tours, France
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26
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Harms PW, Harms KL, Moore PS, DeCaprio JA, Nghiem P, Wong MKK, Brownell I. The biology and treatment of Merkel cell carcinoma: current understanding and research priorities. Nat Rev Clin Oncol 2019; 15:763-776. [PMID: 30287935 PMCID: PMC6319370 DOI: 10.1038/s41571-018-0103-2] [Citation(s) in RCA: 176] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer associated with advanced age and immunosuppression. Over the past decade, an association has been discovered between MCC and either integration of the Merkel cell polyomavirus, which likely drives tumorigenesis, or somatic mutations owing to ultraviolet-induced DNA damage. Both virus-positive and virus-negative MCCs are immunogenic, and inhibition of the programmed cell death protein 1 (PD-1)–programmed cell death 1 ligand 1 (PD-L1) immune checkpoint has proved to be highly effective in treating patients with metastatic MCC; however, not all patients have a durable response to immunotherapy. Despite these rapid advances in the understanding and management of patients with MCC, many basic, translational and clinical research questions remain unanswered. In March 2018, an International Workshop on Merkel Cell Carcinoma Research was held at the US National Cancer Institute, at which academic, government and industry experts met to identify the highest-priority research questions. Here, we review the biology and treatment of MCC and report the consensus-based recommendations agreed upon during the workshop. Merkel cell carcinoma (MCC) is a rare and aggressive form of nonmelanoma skin cancer. The availability of immune checkpoint inhibition has improved the outcomes of a subset of patients with MCC, although many unmet needs continue to exist. In this Consensus Statement, the authors summarize developments in our understanding of MCC while also providing consensus recommendations for future research.
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Affiliation(s)
- Paul W Harms
- Department of Pathology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kelly L Harms
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Patrick S Moore
- Cancer Virology Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - James A DeCaprio
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Paul Nghiem
- Department of Medicine, Division of Dermatology, University of Washington, Seattle, WA, USA
| | - Michael K K Wong
- Department of Melanoma Medical Oncology, Division of Cancer Medicine, MD Anderson Cancer Center, Houston, TX, USA
| | - Isaac Brownell
- Dermatology Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) and National Cancer Institute (NCI), NIH, Bethesda, MD, USA.
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27
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Abdul-Sada H, Müller M, Mehta R, Toth R, Arthur JSC, Whitehouse A, Macdonald A. The PP4R1 sub-unit of protein phosphatase PP4 is essential for inhibition of NF-κB by merkel polyomavirus small tumour antigen. Oncotarget 2018; 8:25418-25432. [PMID: 28445980 PMCID: PMC5421940 DOI: 10.18632/oncotarget.15836] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 02/02/2017] [Indexed: 12/24/2022] Open
Abstract
Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with a high metastatic potential. The majority of MCC cases are caused by the Merkel cell polyomavirus (MCPyV), through expression of the virus-encoded tumour antigens. Whilst mechanisms attributing tumour antigen expression to transformation are being uncovered, little is known of the mechanisms by which MCPyV persists in the host. We previously identified the MCPyV small T antigen (tAg) as a novel inhibitor of nuclear factor kappa B (NF-kB) signalling and a modulator of the host anti-viral response. Here we demonstrate that regulation of NF-kB activation involves a previously undocumented interaction between tAg and regulatory sub-unit 1 of protein phosphatase 4 (PP4R1). Formation of a complex with PP4R1 and PP4c is required to bridge MCPyV tAg to the NEMO adaptor protein, allowing deactivation of the NF-kB pathway. Mutations in MCPyV tAg that fail to interact with components of this complex, or siRNA depletion of PP4R1, prevents tAg-mediated inhibition of NF-kB and pro-inflammatory cytokine production. Comparison of tAg binding partners from other human polyomavirus demonstrates that interactions with NEMO and PP4R1 are unique to MCPyV. Collectively, these data identify PP4R1 as a novel target for virus subversion of the host anti-viral response.
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Affiliation(s)
- Hussein Abdul-Sada
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Marietta Müller
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Rajni Mehta
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Rachel Toth
- Division of Immunology and Cell Signalling and Division of Signal Transduction Therapy College of Life Sciences, University of Dundee, Dundee, UK
| | - J Simon C Arthur
- Division of Immunology and Cell Signalling and Division of Signal Transduction Therapy College of Life Sciences, University of Dundee, Dundee, UK
| | - Adrian Whitehouse
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
| | - Andrew Macdonald
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, UK
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28
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DeCaprio JA. Merkel cell polyomavirus and Merkel cell carcinoma. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0276. [PMID: 28893943 DOI: 10.1098/rstb.2016.0276] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/09/2017] [Indexed: 12/27/2022] Open
Abstract
Merkel cell polyomavirus (MCPyV) causes the highly aggressive and relatively rare skin cancer known as Merkel cell carcinoma (MCC). MCPyV also causes a lifelong yet relatively innocuous infection and is one of 14 distinct human polyomaviruses species. Although polyomaviruses typically do not cause illness in healthy individuals, several can cause catastrophic diseases in immunocompromised hosts. MCPyV is the only polyomavirus clearly associated with human cancer. How MCPyV causes MCC and what oncogenic events must transpire to enable this virus to cause MCC is the focus of this essay.This article is part of the themed issue 'Human oncogenic viruses'.
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Affiliation(s)
- James A DeCaprio
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA .,Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 450 Brookline Avenue, Boston, MA 02215, USA
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29
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Becker JC, Stang A, Hausen AZ, Fischer N, DeCaprio JA, Tothill RW, Lyngaa R, Hansen UK, Ritter C, Nghiem P, Bichakjian CK, Ugurel S, Schrama D. Epidemiology, biology and therapy of Merkel cell carcinoma: conclusions from the EU project IMMOMEC. Cancer Immunol Immunother 2018; 67:341-351. [PMID: 29188306 PMCID: PMC6015651 DOI: 10.1007/s00262-017-2099-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 11/24/2017] [Indexed: 01/23/2023]
Abstract
Merkel cell carcinoma (MCC) is a highly aggressive, often lethal neuroendocrine cancer. Its carcinogenesis may be either caused by the clonal integration of the Merkel cell polyomavirus into the host genome or by UV-induced mutations. Notably, virally-encoded oncoproteins and UV-induced mutations affect comparable signaling pathways such as RB restriction of cell cycle progression or p53 inactivation. Despite its low incidence, MCC recently received much attention based on its exquisite immunogenicity and the resulting major success of immune modulating therapies. Here, we summarize current knowledge on epidemiology, biology and therapy of MCC as conclusion of the project 'Immune Modulating strategies for treatment of Merkel Cell Carcinoma', which was funded over a 5-year period by the European Commission to investigate innovative immunotherapies for MCC.
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Affiliation(s)
- Jürgen C Becker
- Translational Skin Cancer Research (tscr), German Cancer Consortium (DKTK), University Hospital of Essen, Universitätsstrasse 1, S05 T05 B, 45141, Essen, Germany.
- German Cancer Research Center (DKFZ), Heidelberg, Germany.
- Department of Dermatology, University Hospital of Essen, Essen, Germany.
| | - Andreas Stang
- German Cancer Research Center (DKFZ), Heidelberg, Germany
- Center of Clinical Epidemiology; c/o Institute of Medical Informatics, Biometry and Epidemiology, University Hospital of Essen, Essen, Germany
| | - Axel Zur Hausen
- Department of Pathology, Academisch Ziekenhuis Maastricht, Maastricht, The Netherlands
| | - Nicole Fischer
- Institute for Medical Microbiology, Virology and Hygiene, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - James A DeCaprio
- Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA, USA
| | | | - Rikke Lyngaa
- Section for Immunology and Vaccinology, National Veterinary Institute, Technical University of Denmark, Copenhagen, Denmark
| | - Ulla Kring Hansen
- George F. Odland Endowed Chair in Dermatology, University of Washington, Seattle, WA, USA
| | - Cathrin Ritter
- Translational Skin Cancer Research (tscr), German Cancer Consortium (DKTK), University Hospital of Essen, Universitätsstrasse 1, S05 T05 B, 45141, Essen, Germany
- German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Paul Nghiem
- George F. Odland Endowed Chair in Dermatology, University of Washington, Seattle, WA, USA
| | | | - Selma Ugurel
- Department of Dermatology, University Hospital of Essen, Essen, Germany
| | - David Schrama
- Department of Dermatology, University Hospital Wuerzburg, Würzburg, Germany
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30
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Hesbacher S, Pfitzer L, Wiedorfer K, Angermeyer S, Borst A, Haferkamp S, Scholz CJ, Wobser M, Schrama D, Houben R. RB1 is the crucial target of the Merkel cell polyomavirus Large T antigen in Merkel cell carcinoma cells. Oncotarget 2018; 7:32956-68. [PMID: 27121059 PMCID: PMC5078066 DOI: 10.18632/oncotarget.8793] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 03/28/2016] [Indexed: 11/25/2022] Open
Abstract
The pocket protein (PP) family consists of the three members RB1, p107 and p130 all possessing tumor suppressive properties. Indeed, the PPs jointly control the G1/S transition mainly by inhibiting E2F transcription factors. Notably, several viral oncoproteins are capable of binding and inhibiting PPs. Merkel cell polyomavirus (MCPyV) is considered as etiological factor for Merkel cell carcinoma (MCC) with expression of the viral Large T antigen (LT) harboring an intact PP binding domain being required for proliferation of most MCC cells. Therefore, we analyzed the interaction of MCPyV-LT with the PPs. Co-IP experiments indicate that MCPyV-LT binds potently only to RB1. Moreover, MCPyV-LT knockdown-induced growth arrest in MCC cells can be rescued by knockdown of RB1, but not by p107 or p130 knockdown. Accordingly, cell cycle arrest and E2F target gene repression mediated by the single PPs can only in the case of RB1 be significantly reverted by MCPyV-LT expression. Moreover, data from an MCC patient indicate that loss of RB1 rendered the MCPyV-positive MCC cells LT independent. Thus, our results suggest that RB1 is the dominant tumor suppressor PP in MCC, and that inactivation of RB1 by MCPyV-LT is largely sufficient for its growth supporting function in established MCPyV-positive MCC cells.
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Affiliation(s)
- Sonja Hesbacher
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Lisa Pfitzer
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany.,Department of Pharmacy, Center for Drug Research, University of Munich (Ludwigs-Maximilians-Universität), Munich, Germany
| | - Katharina Wiedorfer
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Sabrina Angermeyer
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Andreas Borst
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | | | | | - Marion Wobser
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - David Schrama
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
| | - Roland Houben
- Department of Dermatology, Venereology and Allergology, University Hospital Würzburg, Würzburg, Germany
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31
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Baez CF, Brandão Varella R, Villani S, Delbue S. Human Polyomaviruses: The Battle of Large and Small Tumor Antigens. Virology (Auckl) 2017; 8:1178122X17744785. [PMID: 29238174 PMCID: PMC5721967 DOI: 10.1177/1178122x17744785] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 10/30/2017] [Indexed: 12/17/2022] Open
Abstract
About 40 years ago, the large and small tumor antigens (LT-Ag and sT-Ag) of the polyomavirus (PyVs) simian vacuolating virus 40 have been identified and characterized. To date, it is well known that all the discovered human PyVs (HPyVs) encode these 2 multifunctional and tumorigenic proteins, expressed at viral replication early stage. The 2 T-Ags are able to transform cells both in vitro and in vivo and seem to play a distinct role in the pathogenesis of some tumors in humans. In addition, they are involved in viral DNA replication, transcription, and virion assembly. This short review focuses on the structural and functional features of the HPyVs’ LT-Ag and sT-Ag, with special attention to their transforming properties.
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Affiliation(s)
- Camila Freze Baez
- Department of Preventive Medicine, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Sonia Villani
- Department of Biomedical, Surgical and Dental Sciences, University of Milano, Milano, Italy
| | - Serena Delbue
- Department of Biomedical, Surgical and Dental Sciences, University of Milano, Milano, Italy
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32
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Barton L, Zhao L, Doty JN, Stasko T, Conrad R. An elderly man with a solitary liver lesion. Cytojournal 2017; 14:11. [PMID: 28603540 PMCID: PMC5458409 DOI: 10.4103/1742-6413.207138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 10/03/2016] [Indexed: 11/25/2022] Open
Affiliation(s)
- Lisa Barton
- Address: Department of Pathology and Laboratory Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Lichao Zhao
- Address: Department of Pathology and Laboratory Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Jessica N Doty
- Department of Dermatology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Thomas Stasko
- Department of Dermatology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | - Rachel Conrad
- Address: Department of Pathology and Laboratory Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
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33
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Ritter C, Fan K, Paschen A, Reker Hardrup S, Ferrone S, Nghiem P, Ugurel S, Schrama D, Becker JC. Epigenetic priming restores the HLA class-I antigen processing machinery expression in Merkel cell carcinoma. Sci Rep 2017; 7:2290. [PMID: 28536458 PMCID: PMC5442125 DOI: 10.1038/s41598-017-02608-0] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/12/2017] [Indexed: 12/22/2022] Open
Abstract
Merkel cell carcinoma (MCC) is a rare and aggressive, yet highly immunogenic skin cancer. The latter is due to its viral or UV-associated carcinogenesis. For tumor progression MCC has to escape the host’s immuno-surveillance, e.g. by loss of HLA class-I expression. Indeed, a reduced HLA class-I expression was observed in MCC tumor tissues and MCC cell lines. This reduced HLA class-I surface expression is caused by an impaired expression of key components of the antigen processing machinery (APM), including LMP2 and LMP7 as well as TAP1 and TAP2. Notably, experimental provisions of HLA class-I binding peptides restored HLA class-I surface expression on MCC cells. Silencing of the HLA class-I APM is due to histone deacetylation as inhibition of histone deacetylases (HDACs) not only induced acetylation of histones in the respective promoter regions but also re-expression of APM components. Thus, HDAC inhibition restored HLA class-I surface expression in vitro and in a mouse xenotransplantation model. In contrast to re-induction of HLA class-I by interferons, HDAC inhibitors did not interfere with the expression of immuno-dominant viral proteins. In summary, restoration of HLA class-I expression on MCC cells by epigenetic priming is an attractive approach to enhance therapies boosting adaptive immune responses.
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Affiliation(s)
- Cathrin Ritter
- Department of Translational Skin Cancer Research, University Hospital Essen, Essen, Germany.,German Cancer Consortium (DKTK), Essen, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Kaiji Fan
- Department of Translational Skin Cancer Research, University Hospital Essen, Essen, Germany.,Department of Dermatology, Medical University of Graz, Graz, Austria
| | - Annette Paschen
- Department of Dermatology, University Hospital Essen, Essen, Germany
| | - Sine Reker Hardrup
- Department of Immunology and Vaccinology, Technical University of Denmark, Frederiksberg, Denmark
| | - Soldano Ferrone
- Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Paul Nghiem
- Division of Dermatology, Department of Medicine, University of Washington, Seattle, WA, United States
| | - Selma Ugurel
- Department of Dermatology, University Hospital Essen, Essen, Germany
| | - David Schrama
- Department of Dermatology, University Hospital Würzburg, Würzburg, Germany
| | - Jürgen C Becker
- Department of Translational Skin Cancer Research, University Hospital Essen, Essen, Germany. .,German Cancer Consortium (DKTK), Essen, Germany. .,German Cancer Research Center (DKFZ), Heidelberg, Germany. .,Department of Dermatology, University Hospital Essen, Essen, Germany.
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34
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Gheit T, Dutta S, Oliver J, Robitaille A, Hampras S, Combes JD, McKay-Chopin S, Le Calvez-Kelm F, Fenske N, Cherpelis B, Giuliano AR, Franceschi S, McKay J, Rollison DE, Tommasino M. Isolation and characterization of a novel putative human polyomavirus. Virology 2017; 506:45-54. [PMID: 28342387 DOI: 10.1016/j.virol.2017.03.007] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 03/07/2017] [Accepted: 03/16/2017] [Indexed: 01/08/2023]
Abstract
The small double-stranded DNA polyomaviruses (PyVs) form a family of 73 species, whose natural hosts are primarily mammals and birds. So far, 13 PyVs have been isolated in humans, and some of them have clearly been associated with several diseases, including cancer. In this study, we describe the isolation of a novel PyV in human skin using a sensitive degenerate PCR protocol combined with next-generation sequencing. The new virus, named Lyon IARC PyV (LIPyV), has a circular genome of 5269 nucleotides. Phylogenetic analyses showed that LIPyV is related to the raccoon PyV identified in neuroglial tumours in free-ranging raccoons. Analysis of human specimens from cancer-free individuals showed that 9 skin swabs (9/445; 2.0%), 3 oral gargles (3/140; 2.1%), and one eyebrow hair sample (1/439; 0.2%) tested positive for LIPyV. Future biological and epidemiological studies are needed to confirm the human tropism and provide insights into its biological properties.
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Affiliation(s)
- Tarik Gheit
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Sankhadeep Dutta
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Javier Oliver
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Alexis Robitaille
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Shalaka Hampras
- Department of Cancer Epidemiology, Moffitt Cancer Center, Tampa, FL, USA
| | - Jean-Damien Combes
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Sandrine McKay-Chopin
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | | | - Neil Fenske
- Department of Dermatology & Cutaneous Surgery, University of South Florida, Morsani College of Medicine, Tampa, FL, USA; Department of Cutaneous Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | - Basil Cherpelis
- Department of Dermatology & Cutaneous Surgery, University of South Florida, Morsani College of Medicine, Tampa, FL, USA; Department of Cutaneous Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | - Anna R Giuliano
- Center for Infection Research in Cancer, Moffitt Cancer Center, Tampa, FL, USA
| | - Silvia Franceschi
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - James McKay
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France
| | - Dana E Rollison
- Department of Cancer Epidemiology, Moffitt Cancer Center, Tampa, FL, USA
| | - Massimo Tommasino
- International Agency for Research on Cancer, World Health Organization, Lyon 69372, France.
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35
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Liu W, MacDonald M, You J. Merkel cell polyomavirus infection and Merkel cell carcinoma. Curr Opin Virol 2016; 20:20-27. [PMID: 27521569 DOI: 10.1016/j.coviro.2016.07.011] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 07/26/2016] [Accepted: 07/28/2016] [Indexed: 12/17/2022]
Abstract
Merkel cell polyomavirus is the only polyomavirus discovered to date that is associated with a human cancer. MCPyV infection is highly prevalent in the general population. Nearly all healthy adults asymptomatically shed MCPyV from their skin. However, in elderly and immunosuppressed individuals, the infection can lead to a lethal form of skin cancer, Merkel cell carcinoma. In the last few years, new findings have established links between MCPyV infection, host immune response, and Merkel cell carcinoma development. This review discusses these recent discoveries on how MCPyV interacts with host cells to achieve persistent infection and, in the immunocompromised population, contributes to MCC development.
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Affiliation(s)
- Wei Liu
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Margo MacDonald
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jianxin You
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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36
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Richards KF, Guastafierro A, Shuda M, Toptan T, Moore PS, Chang Y. Merkel cell polyomavirus T antigens promote cell proliferation and inflammatory cytokine gene expression. J Gen Virol 2016; 96:3532-3544. [PMID: 26385761 DOI: 10.1099/jgv.0.000287] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Merkel cell polyomavirus (MCV) is clonally integrated in over 80 % of Merkel cell carcinomas and mediates tumour development through the expression of viral oncoproteins, the large T (LT) and small T antigens (sT). Viral integration is associated with signature mutations in the T-antigen locus that result in deletions of C-terminal replicative functions of the LT antigen. Despite these truncations, the LT LXCXE retinoblastoma (Rb) pocket protein family binding domain is retained, and the entire sT isoform is maintained intact. To investigate the ability of MCV oncoproteins to regulate host gene expression, we performed microarray analysis on cells stably expressing tumour-derived LT, tumour-derived LT along with sT, and tumour-derived LT with a mutated Rb interaction domain. Gene expression alterations in the presence of tumour-derived LT could be classified into three main groups: genes that are involved in the cell cycle (specifically the G1/S transition), genes involved in DNA replication and genes involved in cellular movement. The LXCXE mutant LT largely reversed gene expression alterations detected with the WT tumour-derived LT, while co-expression of sT did not significantly affect these patterns of gene expression. LXCXE-dependent upregulation of cyclin E and CDK2 correlated with increased proliferation in tumour-derived LT-expressing cells. Tumour-derived LT and tumour-derived LT plus sT increased expression of multiple cytokines and chemokines, which resulted in elevated levels of secreted IL-8. We concluded that, in human fibroblasts, the LXCXE motif of tumour-derived LT enhances cellular proliferation and upregulates cell cycle and immune signalling gene transcription.
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Affiliation(s)
| | - Anna Guastafierro
- Cancer Virology Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - Masahiro Shuda
- Cancer Virology Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - Tuna Toptan
- Cancer Virology Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - Patrick S Moore
- Cancer Virology Program, University of Pittsburgh, Pittsburgh, PA, USA
| | - Yuan Chang
- Cancer Virology Program, University of Pittsburgh, Pittsburgh, PA, USA
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37
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Mirvish ED, Shuda M. Strategies for Human Tumor Virus Discoveries: From Microscopic Observation to Digital Transcriptome Subtraction. Front Microbiol 2016; 7:676. [PMID: 27242703 PMCID: PMC4865503 DOI: 10.3389/fmicb.2016.00676] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 04/26/2016] [Indexed: 01/07/2023] Open
Abstract
Over 20% of human cancers worldwide are associated with infectious agents, including viruses, bacteria, and parasites. Various methods have been used to identify human tumor viruses, including electron microscopic observations of viral particles, immunologic screening, cDNA library screening, nucleic acid hybridization, consensus PCR, viral DNA array chip, and representational difference analysis. With the Human Genome Project, a large amount of genetic information from humans and other organisms has accumulated over the last decade. Utilizing the available genetic databases, Feng et al. (2007) developed digital transcriptome subtraction (DTS), an in silico method to sequentially subtract human sequences from tissue or cellular transcriptome, and discovered Merkel cell polyomavirus (MCV) from Merkel cell carcinoma. Here, we review the background and methods underlying the human tumor virus discoveries and explain how DTS was developed and used for the discovery of MCV.
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Affiliation(s)
- Ezra D Mirvish
- Department of Dermatology, University of Pittsburgh Medical Center, Pittsburgh PA, USA
| | - Masahiro Shuda
- Cancer Virology Program, University of Pittsburgh Cancer Institute, University of Pittsburgh, Pittsburgh PA, USA
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38
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Reversal of epigenetic silencing of MHC class I chain-related protein A and B improves immune recognition of Merkel cell carcinoma. Sci Rep 2016; 6:21678. [PMID: 26902929 PMCID: PMC4763224 DOI: 10.1038/srep21678] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2015] [Accepted: 01/18/2016] [Indexed: 12/26/2022] Open
Abstract
Merkel cell carcinoma (MCC) is a virally associated cancer characterized by its aggressive behavior and strong immunogenicity. Both viral infection and malignant transformation induce expression of MHC class I chain-related protein (MIC) A and B, which signal stress to cells of the immune system via Natural Killer group 2D (NKG2D) resulting in elimination of target cells. However, despite transformation and the continued presence of virally-encoded proteins, MICs are only expressed in a minority of MCC tumors in situ and are completely absent on MCC cell lines in vitro. This lack of MIC expression was due to epigenetic silencing via MIC promoter hypo-acetylation; indeed, MIC expression was re-induced by pharmacological inhibition of histone deacetylases (HDACs) both in vitro and in vivo. This re-induction of MICs rendered MCC cells more sensitive to immune-mediated lysis. Thus, epigenetic silencing of MICs is an important immune escape mechanism of MCCs.
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39
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Management of Merkel Cell Carcinoma. CURRENT DERMATOLOGY REPORTS 2015. [DOI: 10.1007/s13671-015-0116-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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40
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Schrama D, Hesbacher S, Angermeyer S, Schlosser A, Haferkamp S, Aue A, Adam C, Weber A, Schmidt M, Houben R. Serine 220 phosphorylation of the Merkel cell polyomavirus large T antigen crucially supports growth of Merkel cell carcinoma cells. Int J Cancer 2015; 138:1153-62. [PMID: 26383606 DOI: 10.1002/ijc.29862] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/02/2015] [Accepted: 09/10/2015] [Indexed: 02/02/2023]
Abstract
Merkel cell polyomavirus (MCPyV) is regarded as a major causal factor for Merkel cell carcinoma (MCC). Indeed, tumor cell growth of MCPyV-positive MCC cells is dependent on the expression of a truncated viral Large T antigen (LT) with an intact retinoblastoma protein (RB)-binding site. Here we determined the phosphorylation pattern of a truncated MCPyV-LT characteristically for MCC by mass spectrometry revealing MCPyV-LT as multi-phospho-protein phosphorylated at several serine and threonine residues. Remarkably, disruption of most of these phosphorylation sites did not affect its ability to rescue knockdown of endogenous T antigens in MCC cells indicating that phosphorylation of the respective amino acids is not essential for the growth promoting function of MCPyV-LT. However, alteration of serine 220 to alanine completely abolished the ability of MCPyV-LT to support proliferation of MCC cells. Conversely, mimicking the phosphorylated state by mutation of serine 220 to glutamic acid resulted in a fully functional LT. Moreover, MCPyV-LT(S220A) demonstrated reduced binding to RB in co-immunoprecipitation experiments as well as weaker induction of RB target genes in MCC cells. In conclusion, we provide evidence that phosphorylation of serine 220 is required for efficient RB inactivation in MCC and may therefore be a potential target for future therapeutic approaches.
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Affiliation(s)
- David Schrama
- Department of Dermatology, University Hospital Würzburg, Germany
| | - Sonja Hesbacher
- Department of Dermatology, University Hospital Würzburg, Germany
| | | | - Andreas Schlosser
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Germany
| | | | - Annemarie Aue
- Department of Dermatology, University Hospital Würzburg, Germany
| | - Christian Adam
- Department of Dermatology, University Hospital Würzburg, Germany
| | - Alexandra Weber
- Department of Dermatology, University Hospital Würzburg, Germany
| | - Marc Schmidt
- Department of Dermatology, University Hospital Würzburg, Germany
| | - Roland Houben
- Department of Dermatology, University Hospital Würzburg, Germany
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41
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Saini AT, Miles BA. Merkel cell carcinoma of the head and neck: pathogenesis, current and emerging treatment options. Onco Targets Ther 2015; 8:2157-67. [PMID: 26316785 PMCID: PMC4548751 DOI: 10.2147/ott.s72202] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Merkel cell carcinoma (MCC) is a relatively uncommon, neuroendocrine, cutaneous malignancy that often exhibits clinically aggressive features and is associated with a poor prognosis. It typically presents as a painless, rapidly enlarging, dome-shaped red or purplish nodule in a sun-exposed area of the head and neck or upper extremities. Our understanding of MCC has increased dramatically over the last several years and the pathogenesis continues to be an area of active research. The etiology is likely multifactorial with immunosuppression, UV-induced skin damage, and viral factors contributing to the development of MCC. The recent discovery of Merkel cell polyomavirus has allowed for at least one aspect of disease development to be much better understood. In most cases, treatment consists of wide local excision with adjuvant radiation therapy. The role of chemotherapeutics is still being defined. The recent advancement of knowledge regarding the pathogenesis of MCC has led to an explosion research into novel therapeutic agents and strategies. This review seeks to summarize the current body of literature regarding the pathogenesis of MCC and potential targets for future therapies.
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Affiliation(s)
- Alok T Saini
- Department of Otolaryngology - Head and Neck Surgery, Mount Sinai Hospital, New York, NY, USA
| | - Brett A Miles
- Department of Otolaryngology - Head and Neck Surgery, Mount Sinai Hospital, New York, NY, USA
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42
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Church CD, Nghiem P. How does the Merkel polyomavirus lead to a lethal cancer? Many answers, many questions, and a new mouse model. J Invest Dermatol 2015; 135:1221-1224. [PMID: 25882464 PMCID: PMC4402710 DOI: 10.1038/jid.2015.4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Merkel cell polyomavirus (MCPyV), discovered in 2008, drives the development of most Merkel cell carcinomas (MCCs) through several canonical mechanisms. A glaring gap in our knowledge remains the basis by which MCPyV, among all 12 human polyomaviruses, is the only one that causes cancer in humans. Moreover, initial attempts by numerous groups have failed to reproduce MCC in mice using oncoproteins from this polyomavirus. Verhaegen et al. report MCPyV small T-antigen-expressing transgenic mice that now provide insight into in vivo transformation mechanisms.
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Affiliation(s)
- Candice D Church
- Department of Medicine/Dermatology, University of Washington, Seattle, Washington, USA
| | - Paul Nghiem
- Department of Medicine/Dermatology, University of Washington, Seattle, Washington, USA; Department of Pathology, University of Washington, Seattle, Washington, USA; Fred Hutchinson Cancer Research Center, Seattle, Washington, USA; Seattle Cancer Care Alliance, Seattle, Washington, USA.
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43
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Characterization of T Antigens, Including Middle T and Alternative T, Expressed by the Human Polyomavirus Associated with Trichodysplasia Spinulosa. J Virol 2015; 89:9427-39. [PMID: 26136575 DOI: 10.1128/jvi.00911-15] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 06/26/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The polyomavirus tumor (T) antigens play crucial roles in viral replication, transcription, and cellular transformation. They are encoded by partially overlapping open reading frames (ORFs) located in the early region through alternative mRNA splicing. The T expression pattern of the trichodysplasia spinulosa-associated polyomavirus (TSPyV) has not been established yet, hampering further study of its pathogenic mechanisms and taxonomic relationship. Here, we characterized TSPyV T antigen expression in human cell lines transfected with the TSPyV early region. Sequencing of T antigen-encoded reverse transcription-PCR (RT-PCR) products revealed three splice donor and acceptor sites creating six mRNA splice products that potentially encode the antigens small T (ST), middle T (MT), large T (LT), tiny T, 21kT, and alternative T (ALTO). Except for 21kT, these splice products were also detected in skin of TSPyV-infected patients. At least three splice products were confirmed by Northern blotting, likely encoding LT, MT, ST, 21kT, and ALTO. Protein expression was demonstrated for LT, ALTO, and possibly MT, with LT detected in the nucleus and ALTO in the cytoplasm of transfected cells. Splice site and start codon mutations indicated that ALTO is encoded by the same splice product that encodes LT and uses internal start codons for initiation. The genuineness of ALTO was indicated by the identification of acetylated N-terminal ALTO peptides by mass spectrometry. Summarizing, TSPyV exhibits an expression pattern characterized by both MT and ALTO expression, combining features of rodent and human polyomaviruses. This unique expression pattern provides important leads for further study of polyomavirus-related disease and for an understanding of polyomavirus evolution. IMPORTANCE The human trichodysplasia spinulosa-associated polyomavirus (TSPyV) is distinguished among polyomaviruses for combining productive infection with cell-transforming properties. In the research presented here, we further substantiate this unique position by indicating expression of both middle T antigen (MT) and alternative T antigen (ALTO) in TSPyV. So far, none of the human polyomaviruses was shown to express MT, which is considered the most important viral oncoprotein of rodent polyomaviruses. Coexpression of ALTO and MT, which involves a conserved, recently recognized overlapping ORF subject to positive selection, has not been observed before for any polyomavirus. As a result of our findings, this study provides valuable new insights into polyomavirus T gene use and expression. Obviously, these insights will be instrumental in further study and gaining an understanding of TSPyV pathogenicity. More importantly, however, they provide important leads with regard to the interrelationship, functionality, and evolution of polyomaviruses as a whole, indicating that TSPyV is a suitable model virus to study these entities further.
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44
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Wendzicki JA, Moore PS, Chang Y. Large T and small T antigens of Merkel cell polyomavirus. Curr Opin Virol 2015; 11:38-43. [PMID: 25681708 DOI: 10.1016/j.coviro.2015.01.009] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 01/19/2015] [Indexed: 12/16/2022]
Abstract
Merkel cell polyomavirus (MCV) is the etiological agent of Merkel cell carcinoma (MCC), a rare and highly lethal human skin cancer. A natural component of skin flora, MCV becomes tumorigenic only after integration into the host DNA together with specific mutations to the viral genome. Research on MCV large T (LT) and small T (sT) antigens, the only viral products expressed in MCC, shows that these major oncoproteins not only possess biochemical functions found in common with other polyomavirus T antigens, but also demonstrate new cellular targets not described in previous polyomavirus models. This review provides a map of the relevant functional motifs and domains in MCV T antigens that have been identified, highlighting their roles in tumorigenesis.
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Affiliation(s)
- Justin A Wendzicki
- Cancer Virology Program, University of Pittsburgh Cancer Institute, Suite 1.8, 5117 Centre Avenue, Pittsburgh, PA 15213, United States
| | - Patrick S Moore
- Cancer Virology Program, University of Pittsburgh Cancer Institute, Suite 1.8, 5117 Centre Avenue, Pittsburgh, PA 15213, United States.
| | - Yuan Chang
- Cancer Virology Program, University of Pittsburgh Cancer Institute, Suite 1.8, 5117 Centre Avenue, Pittsburgh, PA 15213, United States.
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