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Naipauer J, Mesri EA. The Kaposi's sarcoma progenitor enigma: KSHV-induced MEndT-EndMT axis. Trends Mol Med 2023; 29:188-200. [PMID: 36635149 PMCID: PMC9957928 DOI: 10.1016/j.molmed.2022.12.003] [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: 09/29/2022] [Revised: 12/02/2022] [Accepted: 12/13/2022] [Indexed: 01/11/2023]
Abstract
Endothelial-to-mesenchymal transition has been described in tumors as a source of mesenchymal stroma, while the reverse process has been proposed in tumor vasculogenesis and angiogenesis. A human oncogenic virus, Kaposi's sarcoma herpes virus (KSHV), can regulate both processes in order to transit through this transition 'boulevard' when infecting KS oncogenic progenitor cells. Endothelial or mesenchymal circulating progenitor cells can serve as KS oncogenic progenitors recruited by inflammatory cytokines because KSHV can reprogram one into the other through endothelial-to-mesenchymal and mesenchymal-to-endothelial transitions. Through these novel insights, the identity of the potential oncogenic progenitor of KS is revealed while gaining knowledge of the biology of the mesenchymal-endothelial differentiation axis and pointing to this axis as a therapeutic target in KS.
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Affiliation(s)
- Julian Naipauer
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina; Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA; University of Miami- Center for AIDS Research (UM-CFAR)/Sylvester Comprehensive Cancer Center (CCC) Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, USA; Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Enrique A Mesri
- Tumor Biology Program, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA; University of Miami- Center for AIDS Research (UM-CFAR)/Sylvester Comprehensive Cancer Center (CCC) Argentina Consortium for Research and Training in Virally Induced AIDS-Malignancies, University of Miami Miller School of Medicine, Miami, FL, USA; Miami Center for AIDS Research, Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA
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2
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Mohanty S, Kumar A, Das P, Sahu SK, Mukherjee R, Ramachandranpillai R, Nair SS, Choudhuri T. Nm23-H1 induces apoptosis in primary effusion lymphoma cells via inhibition of NF-κB signaling through interaction with oncogenic latent protein vFLIP K13 of Kaposi’s sarcoma-associated herpes virus. Cell Oncol (Dordr) 2022; 45:967-989. [DOI: 10.1007/s13402-022-00701-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2022] [Indexed: 11/03/2022] Open
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3
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Lin CI, Wang SS, Hung CH, Chang PJ, Chen LW. Kaposi’s Sarcoma-Associated Herpesvirus ORF50 Protein Represses Cellular MDM2 Expression via Suppressing the Sp1- and p53-Mediated Transactivation. Int J Mol Sci 2022; 23:ijms23158673. [PMID: 35955808 PMCID: PMC9369062 DOI: 10.3390/ijms23158673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/22/2022] [Accepted: 08/02/2022] [Indexed: 02/05/2023] Open
Abstract
The Kaposi’s sarcoma-associated herpesvirus (KSHV)-encoded ORF50 protein is a potent transcriptional activator essential for triggering KSHV lytic reactivation. Despite extensive studies, little is known about whether ORF50 possesses the ability to repress gene expression or has an antagonistic action to cellular transcription factors. Previously, we demonstrated that human oncoprotein MDM2 can promote the degradation of ORF50 protein. Herein, we show that abundant ORF50 expression in cells can conversely downregulate MDM2 expression via repressing both the upstream (P1) and internal (P2) promoters of the MDM2 gene. Deletion analysis of the MDM2 P1 promoter revealed that there were two ORF50-dependent negative response elements located from −102 to −63 and from −39 to +1, which contain Sp1-binding sites. For the MDM2 P2 promoter, the ORF50-dependent negative response element was identified in the region from −110 to −25, which is coincident with the location of two known p53-binding sites. Importantly, we further demonstrated that overexpression of Sp1 or p53 in cells indeed upregulated MDM2 expression; however, coexpression with ORF50 protein remarkably reduced the Sp1- or p53-mediated MDM2 upregulation. Collectively, our findings propose a reciprocal negative regulation between ORF50 and MDM2 and uncover that ORF50 decreases MDM2 expression through repressing Sp1- and p53-mediated transactivation.
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Affiliation(s)
- Chia-I Lin
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan 33302, Taiwan
| | - Shie-Shan Wang
- Department of Pediatric Surgery, Chang-Gung Memorial Hospital, Chiayi 61363, Taiwan
- School of Medicine, Chang-Gung University, Taoyuan 33302, Taiwan
| | - Chien-Hui Hung
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan 33302, Taiwan
| | - Pey-Jium Chang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan 33302, Taiwan
- Department of Nephrology, Chang-Gung Memorial Hospital, Chiayi 61363, Taiwan
| | - Lee-Wen Chen
- Department of Pediatric Surgery, Chang-Gung Memorial Hospital, Chiayi 61363, Taiwan
- Department of Respiratory Care, Chang-Gung University of Science and Technology, Chiayi 61363, Taiwan
- Correspondence: ; Tel.: +886-5362-8800 (ext. 2235)
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4
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DiMaio TA, Vogt DT, Lagunoff M. KSHV requires vCyclin to overcome replicative senescence in primary human lymphatic endothelial cells. PLoS Pathog 2020; 16:e1008634. [PMID: 32555637 PMCID: PMC7326280 DOI: 10.1371/journal.ppat.1008634] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 06/30/2020] [Accepted: 05/14/2020] [Indexed: 12/13/2022] Open
Abstract
Kaposi's Sarcoma Herpesvirus (KSHV) is present in the main tumor cells of Kaposi's Sarcoma (KS), the spindle cells, which are of endothelial origin. KSHV is also associated with two B-cell lymphomas, Primary Effusion Lymphoma (PEL) and Multicentric Castleman's Disease. In KS and PEL, KSHV is primarily latent in the infected cells, expressing only a few genes. Although KSHV infection is required for KS and PEL, it is unclear how latent gene expression contributes to their formation. Proliferation of cancer cells occurs despite multiple checkpoints intended to prevent dysregulated cell growth. The first of these checkpoints, caused by shortening of telomeres, results in replicative senescence, where cells are metabolically active, but no longer divide. We found that human dermal lymphatic endothelial cells (LECs) are more susceptible to KSHV infection than their blood-specific endothelial cell counterparts and maintain KSHV latency to higher levels during passage. Importantly, KSHV infection of human LECs but not human BECs promotes their continued proliferation beyond this first checkpoint of replicative senescence. The latently expressed viral cyclin homolog is essential for KSHV-induced bypass of senescence in LECs. These data suggest that LECs may be an important reservoir for KSHV infection and may play a role during KS tumor development and that the viral cyclin is a critical oncogene for this process.
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Affiliation(s)
- Terri A. DiMaio
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Daniel T. Vogt
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
| | - Michael Lagunoff
- Department of Microbiology, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Yu X, Ye F. Role of Angiopoietins in Development of Cancer and Neoplasia Associated with Viral Infection. Cells 2020; 9:cells9020457. [PMID: 32085414 PMCID: PMC7072744 DOI: 10.3390/cells9020457] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 02/09/2020] [Accepted: 02/13/2020] [Indexed: 02/06/2023] Open
Abstract
Angiopoietin/tyrosine protein kinase receptor Tie-2 signaling in endothelial cells plays an essential role in angiogenesis and wound healing. Angiopoietin-1 (Ang-1) is crucial for blood vessel maturation while angiopoietin-2 (Ang-2), in collaboration with vascular endothelial growth factor (VEGF), initiates angiogenesis by destabilizing existing blood vessels. In healthy people, the Ang-1 level is sustained while Ang-2 expression is restricted. In cancer patients, Ang-2 level is elevated, which correlates with poor prognosis. Ang-2 not only drives tumor angiogenesis but also attracts infiltration of myeloid cells. The latter rapidly differentiate into tumor stromal cells that foster tumor angiogenesis and progression, and weaken the host’s anti-tumor immunity. Moreover, through integrin signaling, Ang-2 induces expression of matrix metallopeptidases (MMPs) to promote tumor cell invasion and metastasis. Many oncogenic viruses induce expression of Ang-2 to promote development of neoplasia associated with viral infection. Multiple Ang-2 inhibitors exhibit remarkable anti-tumor activities, further highlighting the importance of Ang-2 in cancer development.
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Affiliation(s)
- Xiaolan Yu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, College of Life Sciences, Hubei University, Wuhan 430062, China
- Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan 430062, China
- Correspondence: (X.Y.); (F.Y.); Tel.: +086-27-88661237 (X.Y.); +216-368-8892 (F.Y.)
| | - Fengchun Ye
- Department of Molecular Biology & Microbiology, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA
- Correspondence: (X.Y.); (F.Y.); Tel.: +086-27-88661237 (X.Y.); +216-368-8892 (F.Y.)
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6
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Ding L, Zhu Q, Zhou F, Tan H, Xu W, Pan C, Zhu C, Wang Y, Zhang H, Fu W, Qian Z, Yuan Z, Xu H, Wei F, Cai Q. Identification of viral SIM-SUMO2-interaction inhibitors for treating primary effusion lymphoma. PLoS Pathog 2019; 15:e1008174. [PMID: 31830143 PMCID: PMC6932820 DOI: 10.1371/journal.ppat.1008174] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 12/26/2019] [Accepted: 10/30/2019] [Indexed: 12/19/2022] Open
Abstract
Primary effusion lymphoma (PEL) is an aggressive B-cell malignancy without effective treatment, and caused by the infection of Kaposi’s sarcoma-associated herpesvirus (KSHV), predominantly in its latent form. Previously we showed that the SUMO2-interacting motif within the viral latency-associated nuclear antigen (LANASIM) is essential for establishment and maintenance of KSHV latency. Here, we developed a luciferase based live-cell reporter system to screen inhibitors selectively targeting the interaction between LANASIM and SUMO2. Cambogin, a bioactive natural product isolated from the Garcinia genus (a traditional herbal medicine used for cancer treatment), was obtained from the reporter system screening to efficiently inhibit the association of SUMO2 with LANASIM, in turn reducing the viral episome DNA copy number for establishment and maintenance of KSHV latent infection at a low concentration (nM). Importantly, Cambogin treatments not only specifically inhibited proliferation of KSHV-latently infected cells in vitro, but also induced regression of PEL tumors in a xenograft mouse model. This study has identified Cambogin as a novel therapeutic agent for treating PEL as well as eliminating persistent infection of oncogenic herpesvirus. Primary effusion lymphoma is a common AIDS-associated malignancy caused by infection with Kaposi’s sarcoma-associated herpesvirus (KSHV), and is currently absence of efficient and specific treatment. Natural product from herbal medicines is a major source of drug discovery for the treatment of a variety of diseases. In this study, the authors demonstrated that Cambogin, a polycyclic polyprenylated acylphloroglucinols (PPAPs) isolated from the branches of Garcinia esculenta (a tropical evergreen tree and traditional cancer treatment across Southern Asia), is a potent and effective inhibitor of KSHV-latently infected cells at a low concentration (nM) in vitro and in vivo, through targeting viral LANASIM-SUMO2 interaction.
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Affiliation(s)
- Ling Ding
- MOE& NHC&CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, P. R. China
| | - Qing Zhu
- MOE& NHC&CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, P. R. China
- ShengYushou Center of Cell Biology and Immunology, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P. R. China
| | - Feng Zhou
- Baoji Affiliated Hospital of Xi’an Medical University, Baoji & MOE Key Laboratory of Western Resources and Modern Biotechnology, College of Life Sciences, Northwest University, Xi’an, Shaanxi, China
| | - Hongsheng Tan
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine & Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Wenjia Xu
- Unit of Herpesvirus and Molecular Virology, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, Shanghai, P. R. China
| | - Chengling Pan
- Beijing Computing Center, Beijing Academy of Science and Technology & Beijing Beike Deyuan Bio-Pharm Technology Company, Beijing, P. R. China
| | - Caixia Zhu
- MOE& NHC&CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, P. R. China
| | - Yuyan Wang
- MOE& NHC&CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, P. R. China
| | - Hong Zhang
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine & Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Wenwei Fu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine & Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
| | - Zhikang Qian
- Unit of Herpesvirus and Molecular Virology, Key Laboratory of Molecular Virology & Immunology, Institut Pasteur of Shanghai, Chinese Academy of Sciences, University of the Chinese Academy of Sciences, Shanghai, P. R. China
| | - Zhenghong Yuan
- MOE& NHC&CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, P. R. China
| | - Hongxi Xu
- School of Pharmacy, Shanghai University of Traditional Chinese Medicine & Engineering Research Center of Shanghai Colleges for TCM New Drug Discovery, Shanghai, China
- * E-mail: (HX); (FW); (QC)
| | - Fang Wei
- ShengYushou Center of Cell Biology and Immunology, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, P. R. China
- * E-mail: (HX); (FW); (QC)
| | - Qiliang Cai
- MOE& NHC&CAMS Key Laboratory of Medical Molecular Virology, School of Basic Medical Science, Shanghai Medical College, Fudan University, Shanghai, P. R. China
- Expert Workstation, Baoji Central Hospital, Baoji, P. R. China
- * E-mail: (HX); (FW); (QC)
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He M, Cheng F, da Silva SR, Tan B, Sorel O, Gruffaz M, Li T, Gao SJ. Molecular Biology of KSHV in Relation to HIV/AIDS-Associated Oncogenesis. Cancer Treat Res 2019; 177:23-62. [PMID: 30523620 DOI: 10.1007/978-3-030-03502-0_2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Discovered in 1994, Kaposi's sarcoma-associated herpesvirus (KSHV) has been associated with four human malignancies including Kaposi's sarcoma, primary effusion lymphoma, a subset of multicentric Castleman's disease, and KSHV inflammatory cytokine syndrome. These malignancies mostly occur in immunocompromised patients including patients with acquired immunodeficiency syndrome and often cause significant mortality because of the lack of effective therapies. Significant progresses have been made to understand the molecular basis of KSHV infection and KSHV-induced oncogenesis in the last two decades. This chapter provides an update on the recent advancements focusing on the molecular events of KSHV primary infection, the mechanisms regulating KSHV life cycle, innate and adaptive immunity, mechanism of KSHV-induced tumorigenesis and inflammation, and metabolic reprogramming in KSHV infection and KSHV-transformed cells.
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Affiliation(s)
- Meilan He
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Fan Cheng
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Suzane Ramos da Silva
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Brandon Tan
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Océane Sorel
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Marion Gruffaz
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Tingting Li
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Shou-Jiang Gao
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, USA.
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8
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Mohanty S, Kumar A, Das P, Sahu SK, Choudhuri T. Multi-targeted therapy of everolimus in Kaposi's sarcoma associated herpes virus infected primary effusion lymphoma. Apoptosis 2018; 22:1098-1115. [PMID: 28653223 DOI: 10.1007/s10495-017-1391-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Kaposi's sarcoma associated herpes virus (KSHV) infected primary effusion lymphoma (PEL) is a rare aggressive form of non-Hodgkin's lymphoma of B cells. KSHV latent and lytic antigens modulate several host cellular signalling pathways especially mammalian target of rapamycin (mTOR), STAT-3 and nuclear factor-kappa B (NF-κB) for rapid tumor progression and immune evasion. Current chemotherapeutic strategies are becoming ineffective as they kill only dividing cells and inefficient to target molecular pathways crucial for active virus replication and its survival. In this study, we evaluated the efficacy of everolimus, an mTOR inhibitor in inducing apoptosis of PEL cells. Dose-dependent treatment of everolimus triggered mitochondria-mediated caspase-dependent apoptosis in PEL cells. Everolimus downregulated KSHV latent antigen expression with concurrent blocking of lytic reactivation for active virus replication. Everolimus also inhibited latent antigen mediated constitutively active STAT-3 and NF-κB signalling. We co-cultured everolimus treated PEL cells with immature dendritic cells and found activation of dendritic cells with increase in surface expression of CD86 and HLA-DR. As everolimus targets and disrupts KSHV antigens as well as antigen facilitated multiple signalling pathways necessary for KSHV survival and maintenance of infection with synchronised boosting of immune system against viral infection, it can be a better therapeutic approach towards treatment of PEL.
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Affiliation(s)
- Suchitra Mohanty
- Division of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, India
| | - Amit Kumar
- Division of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, India
| | - Piyanki Das
- Department of Biotechnology, Siksha Bhabana, Visva Bharati, Santiniketan, Bolpur, India
| | - Sushil Kumar Sahu
- Division of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, India
| | - Tathagata Choudhuri
- Department of Biotechnology, Siksha Bhabana, Visva Bharati, Santiniketan, Bolpur, India.
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Innis-Whitehouse W, Wang X, Restrepo N, Salas C, Moreno K, Restrepo A, Keniry M. Kaposi sarcoma incidence in females is nearly four-fold higher in the Lower Rio Grande Valley compared to the Texas average. Cancer Treat Res Commun 2018; 16:45-52. [PMID: 31299002 DOI: 10.1016/j.ctarc.2018.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 06/09/2018] [Accepted: 06/11/2018] [Indexed: 12/17/2022]
Abstract
The Lower Rio Grande Valley (LRGV) is located on U.S.-Mexican border with a population that is 90% Hispanic [1]. Comprised of Hidalgo, Cameron, Starr and Willacy counties, this region has the highest poverty rate and one of the highest incidences of Type 2 diabetes in the United States [2-4]. Previous studies demonstrated a high prevalence of Human Herpes Virus 8 (HHV8) in the LRGV [5-7]. HHV8 infection has been causally linked to Kaposi Sarcoma (KS) [8]. Here, we retrospectively examine the incidence of KS in the LRGV in a set of HIV-negative Hispanic patients. Strikingly, the incidence of KS was higher in LRGV women compared to the Texas state average (nearly four-fold higher in McAllen-Edinburg-Pharr Metro Statistical Area). This unique profile aligns with the increased HHV8 prevalence in the LRGV, suggesting that HHV8 contributes to a high incidence of HIV-negative KS on the U.S.-Mexican border in Texas.
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Affiliation(s)
- Wendy Innis-Whitehouse
- School of Medicine, The University of Texas Rio Grande Valley, 1201 W. University Dr., Edinburg, TX 78539, USA.
| | - Xiaohui Wang
- School of Mathematical and Statistical Sciences, The University of Texas Rio Grande Valley, 1201 W. University Dr., Edinburg, TX 78539, USA.
| | - Nicolas Restrepo
- Department of Biology, The University of Texas Rio Grande Valley, 1201 W. University Dr., Edinburg, TX 78539, USA.
| | - Carlos Salas
- Department of Biology, The University of Texas Rio Grande Valley, 1201 W. University Dr., Edinburg, TX 78539, USA.
| | - Katia Moreno
- Texas Oncology, 1901 S. 2nd St., McAllen, TX 78503, USA.
| | | | - Megan Keniry
- Department of Biology, The University of Texas Rio Grande Valley, 1201 W. University Dr., Edinburg, TX 78539, USA.
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Low-dose Actinomycin-D treatment re-establishes the tumoursuppressive function of P53 in RELA-positive ependymoma. Oncotarget 2018; 7:61860-61873. [PMID: 27556362 PMCID: PMC5308696 DOI: 10.18632/oncotarget.11452] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 07/27/2016] [Indexed: 12/25/2022] Open
Abstract
Ependymomas in children can arise throughout all compartments of the central nervous system (CNS). Highly malignant paediatric ependymoma subtypes are Group A tumours of the posterior fossa (PF-EPN-A) and RELA-fusion positive (ST-EPN-RELA) tumours in the supratentorial compartment. It was repeatedly reported in smaller series that accumulation of p53 is frequently observed in ependymomas and that immunohistochemical staining correlates with poor clinical outcome, while TP53 mutations are rare. Our TP53 mutation analysis of 130 primary ependymomas identified a mutation rate of only 3%. Immunohistochemical analysis of 398 ependymomas confirmed previous results correlating the accumulation of p53 with inferior outcome. Among the p53-positive ependymomas, the vast majority exhibited a RELA fusion leading to the hypothesis that p53 inactivation might be linked to RELA positivity. In order to assess the potential of p53 reactivation through MDM2 inhibition in ependymoma, we evaluated the effects of Actinomycin-D and Nutlin-3 treatment in two preclinical ependymoma models representing the high-risk subtypes PF-EPN-A and ST-EPN-RELA. The IC-50 of the agent as determined by metabolic activity assays was in the lower nano-molar range (0.2–0.7 nM). Transcriptome analyses of high-dose (100 nM), low-dose (5 nM) and non-treated cells revealed re-expression of p53 dependent genes including p53 upregulated modulator of apoptosis (PUMA) after low-dose treatment. At the protein level, we validated the Actinomycin-D induced upregulation of PUMA, and of p53 interaction partners MDM2 and p21. Proapoptotic effects of low-dose application of the agent were confirmed by flow cytometry. Thus, Actinomycin-D could constitute a promising therapeutic option for ST-EPN-RELA ependymoma patients, whose tumours frequently exhibit p53 inactivation.
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Gelgor A, Gam Ze Letova C, Yegorov Y, Kalt I, Sarid R. Nucleolar stress enhances lytic reactivation of the Kaposi's sarcoma-associated herpesvirus. Oncotarget 2018; 9:13822-13833. [PMID: 29568397 PMCID: PMC5862618 DOI: 10.18632/oncotarget.24497] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 02/01/2018] [Indexed: 02/07/2023] Open
Abstract
Kaposi's sarcoma-associated herpesvirus (KSHV) is a human tumorigenic virus exhibiting two forms of infection, latent and lytic. Latent infection is abortive and allows the virus to establish lifelong infection, while lytic infection is productive, and is needed for virus dissemination within the host and between hosts. Latent infection may reactivate and switch towards the lytic cycle. This switch is a critical step in the maintenance of long-term infection and for the development of KSHV-related neoplasms. In this study, we examined the effect of nucleolar stress, manifested by failure in ribosome biogenesis or function and often coupled with p53 activation, on lytic reactivation of KSHV. To this end, we induced nucleolar stress by treatment with Actinomycin D, CX-5461 or BMH-21. Treatment with these compounds alone did not induce the lytic cycle. However, enhancement of the lytic cycle by these compounds was evident when combined with expression of the viral protein K-Rta. Further experiments employing combined treatments with Nutlin-3, knock-down of p53 and isogenic p53+/+ and p53-/- cells indicated that the enhancement of lytic reactivation by nucleolar stress does not depend on p53. Thus, our study identifies nucleolar stress as a novel regulator of KSHV infection, which synergizes with K-Rta expression to increase lytic reactivation. This suggests that certain therapeutic interventions, which induce nucleolar stress, may affect the outcome of KSHV infection.
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Affiliation(s)
- Anastasia Gelgor
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan, Israel
| | - Chen Gam Ze Letova
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan, Israel
| | - Yana Yegorov
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan, Israel
| | - Inna Kalt
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan, Israel
| | - Ronit Sarid
- The Mina and Everard Goodman Faculty of Life Sciences and Advanced Materials and Nanotechnology Institute, Bar Ilan University, Ramat-Gan, Israel
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12
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Yee-Lin V, Pooi-Fong W, Soo-Beng AK. Nutlin-3, A p53-Mdm2 Antagonist for Nasopharyngeal Carcinoma Treatment. Mini Rev Med Chem 2018; 18:173-183. [PMID: 28714398 PMCID: PMC5769085 DOI: 10.2174/1389557517666170717125821] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 04/07/2017] [Accepted: 04/16/2017] [Indexed: 01/08/2023]
Abstract
Nasopharyngeal carcinoma (NPC) is a form of head and neck cancer of multifactorial etiolo-gies that is highly prevalent among men in the population of Southern China and Southeast Asia. NPC has claimed many thousands of lives worldwide; but the low awareness of NPC remains a hindrance in early diagnosis and prevention of the disease. NPC is highly responsive to radiotherapy and chemothera-py, but radiocurable NPC is still dependent on concurrent treatment of megavoltage radiotherapy with chemotherapy. Despite a significant reduction in loco-regional and distant metastases, radiotherapy alone has failed to provide a significant improvement in the overall survival rate of NPC, compared to chemo-therapy. In addition, chemo-resistance persists as the major challenge in the management of metastatic NPC although the survival rate of advanced metastatic NPC has significantly improved with the admin-istration of chemotherapy adjunctive to radiotherapy. In this regard, targeted molecular therapy could be explored for the discovery of alternative NPC therapies. Nutlin-3, a small molecule inhibitor that specifi-cally targets p53-Mdm2 interaction offers new therapeutic opportunities by enhancing cancer cell growth arrest and apoptosis through the restoration of the p53-mediated tumor suppression pathway while pro-ducing minimal cytotoxicity and side effects. This review discusses the potential use of Nutlin-3 as a p53-activating drug and the future directions of its clinical research for NPC treatment.
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Affiliation(s)
- Voon Yee-Lin
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur. Malaysia
| | - Wong Pooi-Fong
- Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur. Malaysia
| | - Alan Khoo Soo-Beng
- Molecular Pathology Unit, Cancer Research Centre, Institute for Medical Research, 50588 Kuala Lumpur. Malaysia
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13
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Li Y, Stockton ME, Bhuiyan I, Eisinger BE, Gao Y, Miller JL, Bhattacharyya A, Zhao X. MDM2 inhibition rescues neurogenic and cognitive deficits in a mouse model of fragile X syndrome. Sci Transl Med 2017; 8:336ra61. [PMID: 27122614 DOI: 10.1126/scitranslmed.aad9370] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Accepted: 04/08/2016] [Indexed: 12/15/2022]
Abstract
Fragile X syndrome, the most common form of inherited intellectual disability, is caused by loss of the fragile X mental retardation protein (FMRP). However, the mechanism remains unclear, and effective treatment is lacking. We show that loss of FMRP leads to activation of adult mouse neural stem cells (NSCs) and a subsequent reduction in the production of neurons. We identified the ubiquitin ligase mouse double minute 2 homolog (MDM2) as a target of FMRP. FMRP regulates Mdm2 mRNA stability, and loss of FMRP resulted in elevated MDM2 mRNA and protein. Further, we found that increased MDM2 expression led to reduced P53 expression in adult mouse NSCs, leading to alterations in NSC proliferation and differentiation. Treatment with Nutlin-3, a small molecule undergoing clinical trials for treating cancer, specifically inhibited the interaction of MDM2 with P53, and rescued neurogenic and cognitive deficits in FMRP-deficient mice. Our data reveal a potential regulatory role for FMRP in the balance between adult NSC activation and quiescence, and identify a potential new treatment for fragile X syndrome.
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Affiliation(s)
- Yue Li
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA. Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | | | - Ismat Bhuiyan
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Brian E Eisinger
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA. Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Yu Gao
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA. Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Jessica L Miller
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | | | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA. Department of Neuroscience, University of Wisconsin-Madison, Madison, WI 53705, USA.
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14
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Kaposi's Sarcoma-Associated Herpesvirus MicroRNAs Target GADD45B To Protect Infected Cells from Cell Cycle Arrest and Apoptosis. J Virol 2017; 91:JVI.02045-16. [PMID: 27852859 DOI: 10.1128/jvi.02045-16] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Accepted: 11/15/2016] [Indexed: 12/25/2022] Open
Abstract
Kaposi's sarcoma is one of the most common malignancies in HIV-infected individuals. The responsible agent, Kaposi's sarcoma-associated herpesvirus (KSHV; HHV8), expresses multiple microRNAs (miRNAs), but the targets and functions of these miRNAs are not completely understood. After infection in primary endothelial cells with KSHV, growth arrest DNA damage-inducible gene 45 beta (GADD45B) is one of the most repressed genes using genomic expression profiling. GADD45B was also repressed in mRNA expression profiling experiments when KSHV miRNAs were introduced to uninfected cells. We hypothesized that KSHV miRNAs target human GADD45B to protect cells from consequences of DNA damage, which can be triggered by viral infection. Expression of GADD45B protein is induced by the p53 activator, Nutlin-3, and KSHV miRNA-K9 inhibits this induction. In addition, Nutlin-3 increased apoptosis and cell cycle arrest based on flow cytometry assays. KSHV miR-K9 protected primary endothelial cells from apoptosis and cell cycle arrest following Nutlin-3 treatment. Similar protective phenotypes were seen for targeting GADD45B with short interfering RNAs (siRNAs), as with miR-K9. KSHV miR-K9 also decreased the protein levels of cleaved caspase-3, cleaved caspase-7, and cleaved poly(ADP-ribose) polymerase (PARP). In B lymphocytes latently infected with KSHV, specific inhibitors of KSHV miR-K9 led to increased GADD45B expression and apoptosis, indicating that miR-K9 is important for reducing apoptosis in infected cells. Furthermore, ectopic expression of GADD45B in KSHV-infected cells promoted apoptosis. Together, these results identify a new miRNA target and demonstrate that KSHV miRNAs are important for protecting infected cells from DNA damage responses. IMPORTANCE Kaposi's sarcoma-associated herpesvirus is a leading cause of cancers in individuals with AIDS. Promoting survival of infected cells is essential for maintaining viral infections. A virus needs to combat various cellular defense mechanisms designed to eradicate the viral infection. One such response can include DNA damage response factors, which can promote an arrest in cell growth and trigger cell death. We used a new approach to search for human genes repressed by small nucleic acids (microRNAs) expressed by a gammaherpesvirus (KSHV), which identified a gene called GADD45B as a target of microRNAs. Repression of GADD45B, which is expressed in response to DNA damage, benefited survival of infected cells in response to a DNA damage response. This information could be used to design new treatments for herpesvirus infections.
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15
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Chang TH, Wang SS, Chen LW, Shih YJ, Chang LK, Liu ST, Chang PJ. Regulation of the Abundance of Kaposi's Sarcoma-Associated Herpesvirus ORF50 Protein by Oncoprotein MDM2. PLoS Pathog 2016; 12:e1005918. [PMID: 27698494 PMCID: PMC5047794 DOI: 10.1371/journal.ppat.1005918] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 09/06/2016] [Indexed: 01/10/2023] Open
Abstract
The switch between latency and the lytic cycle of Kaposi's sarcoma-associated herpesvirus (KSHV) is controlled by the expression of virally encoded ORF50 protein. Thus far, the regulatory mechanism underlying the protein stability of ORF50 is unknown. Our earlier studies have demonstrated that a protein abundance regulatory signal (PARS) at the ORF50 C-terminal region modulates its protein abundance. The PARS region consists of PARS-I (aa 490-535) and PARS-II (aa 590-650), and mutations in either component result in abundant expression of ORF50. Here, we show that ORF50 protein is polyubiquitinated and its abundance is controlled through the proteasomal degradation pathway. The PARS-I motif mainly functions as a nuclear localization signal in the control of ORF50 abundance, whereas the PARS-II motif is required for the binding of ubiquitin enzymes in the nucleus. We find that human oncoprotein MDM2, an ubiquitin E3 ligase, is capable of interacting with ORF50 and promoting ORF50 degradation in cells. The interaction domains between both proteins are mapped to the PARS region of ORF50 and the N-terminal 220-aa region of MDM2. Additionally, we identify lysine residues at positions 152 and 154 in the N-terminal domain of ORF50 critically involved in MDM2-mediated downregulation of ORF50 levels. Within KSHV-infected cells, the levels of MDM2 were greatly reduced during viral lytic cycle and genetic knockdown of MDM2 in these cells favored the enhancement of ORF50 expression, supporting that MDM2 is a negative regulator of ORF50 expression. Collectively, the study elucidates the regulatory mechanism of ORF50 stability and implicates that MDM2 may have a significant role in the maintenance of viral latency by lowering basal level of ORF50.
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Affiliation(s)
- Tzu-Hsuan Chang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Shie-Shan Wang
- Department of Pediatric Surgery, Chang-Gung Memorial Hospital, Chiayi, Taiwan
| | - Lee-Wen Chen
- Department of Respiratory Care, Chang-Gung University of Science and Technology, Chiayi, Taiwan
| | - Ying-Ju Shih
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
| | - Li-Kwan Chang
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Shih-Tung Liu
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
- Department of Microbiology and Immunology, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
- * E-mail: (STL); (PJC)
| | - Pey-Jium Chang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang-Gung University, Taoyuan, Taiwan
- Department of Nephrology, Chang-Gung Memorial Hospital, Chiayi, Taiwan
- * E-mail: (STL); (PJC)
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16
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da Mota MF, Cortez AP, Benfica PL, Rodrigues BDS, Castro TF, Macedo LM, Castro CH, Lião LM, de Carvalho FS, Romeiro LAS, Menegatti R, Verli H, Villavicencio B, Valadares MC. Induction of apoptosis in Ehrlich ascites tumour cells via p53 activation by a novel small-molecule MDM2 inhibitor - LQFM030. ACTA ACUST UNITED AC 2016; 68:1143-59. [PMID: 27350017 DOI: 10.1111/jphp.12573] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 04/30/2016] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The activation of the p53 pathway through the inhibition of MDM2 has been proposed as a novel therapeutic strategy against tumours. A series of cis-imidazoline analogues, termed nutlins, were reported to displace the recombinant p53 protein from its complex with MDM2 by binding to MDM2 in the p53 pocket, and exhibited an antitumour activity both in vitro and in vivo. Thus, the purpose of this study was to evaluate the antitumour properties of LQFM030 (2), a nutlin analogue created by employing the strategy of molecular simplification. METHODS LQFM030 (2) cytotoxicity was evaluated in Ehrlich ascites tumour (EAT) cells, p53 wild type, by the trypan blue exclusion test, and the mechanisms involved in EAT cell death were investigated by light and fluorescence microscopy, flow cytometry, real-time PCR and Western blotting. KEY FINDINGS Our results demonstrate that LQFM030 has dose-dependent antiproliferative activity and cytotoxic activity on EAT cells, induces the accumulation of p53 protein and promotes cell cycle arrest and apoptosis. p53 gene transcription was unaffected by LQFM030 (2); however, MDM2 mRNA increased and MDM2 protein decreased. CONCLUSIONS These results suggest that the small-molecule p53 activator LQFM030 (2) has the potential for further development as a novel cancer therapeutic agent.
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Affiliation(s)
- Mariana F da Mota
- Laboratório de Farmacologia e Toxicologia Celular, FarmaTec, Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil.,Lab. de Biologia e DNA Forense da Polícia Técnico-Científica de Goiás, GO - Brazil, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Alane P Cortez
- Laboratório de Farmacologia e Toxicologia Celular, FarmaTec, Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Polyana L Benfica
- Laboratório de Farmacologia e Toxicologia Celular, FarmaTec, Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Bruna Dos S Rodrigues
- Laboratório de Farmacologia e Toxicologia Celular, FarmaTec, Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Thalyta F Castro
- Laboratório de Farmacologia e Toxicologia Celular, FarmaTec, Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Larissa M Macedo
- Departamento de Fisiologia e Farmacologia, Instituto de Ciências Biologicas, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Carlos H Castro
- Departamento de Fisiologia e Farmacologia, Instituto de Ciências Biologicas, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Luciano M Lião
- Instituto de Química, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Flávio S de Carvalho
- Instituto de Química, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil.,Laboratório de Química Farmacêutica Medicinal (LQFM), Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Luiz A S Romeiro
- Faculdade de Ciências da Saúde, Universidade de Brasília, UNB, Brasília, DF, Brazil
| | - Ricardo Menegatti
- Laboratório de Química Farmacêutica Medicinal (LQFM), Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
| | - Hugo Verli
- Centro de Biotecnologia, Universidade Federal de Rio Grande do Sul, UFRS, Porto Alegre, RS, Brazil
| | - Bianca Villavicencio
- Centro de Biotecnologia, Universidade Federal de Rio Grande do Sul, UFRS, Porto Alegre, RS, Brazil
| | - Marize C Valadares
- Laboratório de Farmacologia e Toxicologia Celular, FarmaTec, Faculdade de Farmácia, Universidade Federal de Goiás, UFG, Goiânia, GO, Brazil
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17
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Yu X, Sha J, Xiang S, Qin S, Conrad P, Ghosh SK, Weinberg A, Ye F. Suppression of KSHV-induced angiopoietin-2 inhibits angiogenesis, infiltration of inflammatory cells, and tumor growth. Cell Cycle 2016; 15:2053-65. [PMID: 27294705 DOI: 10.1080/15384101.2016.1196303] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Kaposi's sarcoma (KS) is a highly angiogenic and inflammatory neoplasia. The angiogenic and inflammatory cytokine angiopoietin-2 (Ang-2) is strongly expressed in KS due to Kaposi's sarcoma-associated herpesvirus (KSHV) infection. In the present study, we determined how Ang-2 contributes to development of KS by using telomerase-immortalized human umbilical vein endothelial cells (TIVE) as a model, which become malignantly transformed and express increased levels of Ang-2 following KSHV infection. Ang-2 released from TIVE-KSHV cells induces tyrosine phosphorylation of Tie-2 receptor from both human and mouse endothelial cells and promotes angiogenesis in nude mice. Functional inhibition or expressional "knock-down" of Ang-2 in these cells blocks angiogenesis and inhibits tumor growth. Ang-2 suppression also reduces the numbers of infiltrating monocytes/macrophages in tumors. In transwell-based cell migration assays, Ang-2 indeed enhances migration of human monocytes in a dose-dependent manner. These results underscore a pivotal role of KSHV-induced Ang-2 in KS tumor development by promoting both angiogenesis and inflammation. Our data also suggest that selective drug targeting of Ang-2 may be used for treatment of KS.
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Affiliation(s)
- Xiaolan Yu
- a Department of Biological Sciences , School of Dental Medicine, Case Western Reserve University , Cleveland , OH , USA.,b Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, College of Life Sciences, Hubei University , Wuhan , Hubei , China
| | - Jingfeng Sha
- a Department of Biological Sciences , School of Dental Medicine, Case Western Reserve University , Cleveland , OH , USA
| | - Shao Xiang
- a Department of Biological Sciences , School of Dental Medicine, Case Western Reserve University , Cleveland , OH , USA
| | - Sanhai Qin
- a Department of Biological Sciences , School of Dental Medicine, Case Western Reserve University , Cleveland , OH , USA
| | - Patricia Conrad
- c Department of Genetics , School of Medicine, Case Western Reserve University , Cleveland , OH , USA
| | - Santosh K Ghosh
- a Department of Biological Sciences , School of Dental Medicine, Case Western Reserve University , Cleveland , OH , USA
| | - Aaron Weinberg
- a Department of Biological Sciences , School of Dental Medicine, Case Western Reserve University , Cleveland , OH , USA
| | - Fengchun Ye
- a Department of Biological Sciences , School of Dental Medicine, Case Western Reserve University , Cleveland , OH , USA
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18
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Di Domenico EG, Toma L, Bordignon V, Trento E, D'Agosto G, Cordiali-Fei P, Ensoli F. Activation of DNA Damage Response Induced by the Kaposi's Sarcoma-Associated Herpes Virus. Int J Mol Sci 2016; 17:ijms17060854. [PMID: 27258263 PMCID: PMC4926388 DOI: 10.3390/ijms17060854] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Revised: 05/23/2016] [Accepted: 05/27/2016] [Indexed: 01/24/2023] Open
Abstract
The human herpes virus 8 (HHV-8), also known as Kaposi sarcoma-associated herpes virus (KSHV), can infect endothelial cells often leading to cell transformation and to the development of tumors, namely Kaposi’s sarcoma (KS), primary effusion lymphoma (PEL), and the plasmablastic variant of multicentric Castleman’s disease. KSHV is prevalent in areas such as sub-Saharan Africa and the Mediterranean region presenting distinct genotypes, which appear to be associated with differences in disease manifestation, according to geographical areas. In infected cells, KSHV persists in a latent episomal form. However, in a limited number of cells, it undergoes spontaneous lytic reactivation to ensure the production of new virions. During both the latent and the lytic cycle, KSHV is programmed to express genes which selectively modulate the DNA damage response (DDR) through the activation of the ataxia telangiectasia mutated (ATM) pathway and by phosphorylating factors associated with the DDR, including the major tumor suppressor protein p53 tumor suppressor p53. This review will focus on the interplay between the KSHV and the DDR response pathway throughout the viral lifecycle, exploring the putative molecular mechanism/s that may contribute to malignant transformation of host cells.
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Affiliation(s)
- Enea Gino Di Domenico
- Clinical Pathology and Microbiology Department, San Gallicano Institute, IRCCS, Rome 00144, Italy.
| | - Luigi Toma
- Infectious Disease Consultant, San Gallicano Institute, IRCCS, Rome 00144, Italy.
| | - Valentina Bordignon
- Clinical Pathology and Microbiology Department, San Gallicano Institute, IRCCS, Rome 00144, Italy.
| | - Elisabetta Trento
- Clinical Pathology and Microbiology Department, San Gallicano Institute, IRCCS, Rome 00144, Italy.
| | - Giovanna D'Agosto
- Clinical Pathology and Microbiology Department, San Gallicano Institute, IRCCS, Rome 00144, Italy.
| | - Paola Cordiali-Fei
- Clinical Pathology and Microbiology Department, San Gallicano Institute, IRCCS, Rome 00144, Italy.
| | - Fabrizio Ensoli
- Clinical Pathology and Microbiology Department, San Gallicano Institute, IRCCS, Rome 00144, Italy.
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19
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Wei F, Gan J, Wang C, Zhu C, Cai Q. Cell Cycle Regulatory Functions of the KSHV Oncoprotein LANA. Front Microbiol 2016; 7:334. [PMID: 27065950 PMCID: PMC4811921 DOI: 10.3389/fmicb.2016.00334] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/03/2016] [Indexed: 12/13/2022] Open
Abstract
Manipulation of cell cycle is a commonly employed strategy of viruses for achieving a favorable cellular environment during infection. Kaposi’s sarcoma-associated herpesvirus (KSHV), the primary etiological agent of several human malignancies including Kaposi’s sarcoma, and primary effusion lymphoma, encodes several oncoproteins that deregulate normal physiology of cell cycle machinery to persist with endothelial cells and B cells and subsequently establish a latent infection. During latency, only a small subset of viral proteins is expressed. Latency-associated nuclear antigen (LANA) is one of the latent antigens shown to be essential for transformation of endothelial cells in vitro. It has been well demonstrated that LANA is critical for the maintenance of latency, episome DNA replication, segregation and gene transcription. In this review, we summarize recent studies and address how LANA functions as an oncoprotein to steer host cell cycle-related events including proliferation and apoptosis by interacting with various cellular and viral factors, and highlight the potential therapeutic strategy of disrupting LANA-dependent signaling as targets in KSHV-associated cancers.
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Affiliation(s)
- Fang Wei
- ShengYushou Center of Cell Biology and Immunology, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University Shanghai, China
| | - Jin Gan
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College, Fudan University Shanghai, China
| | - Chong Wang
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College, Fudan University Shanghai, China
| | - Caixia Zhu
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College, Fudan University Shanghai, China
| | - Qiliang Cai
- MOE & MOH Key Laboratory of Medical Molecular Virology, School of Basic Medicine, Shanghai Medical College, Fudan University Shanghai, China
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20
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Balistreri G, Viiliäinen J, Turunen M, Diaz R, Lyly L, Pekkonen P, Rantala J, Ojala K, Sarek G, Teesalu M, Denisova O, Peltonen K, Julkunen I, Varjosalo M, Kainov D, Kallioniemi O, Laiho M, Taipale J, Hautaniemi S, Ojala PM. Oncogenic Herpesvirus Utilizes Stress-Induced Cell Cycle Checkpoints for Efficient Lytic Replication. PLoS Pathog 2016; 12:e1005424. [PMID: 26891221 PMCID: PMC4758658 DOI: 10.1371/journal.ppat.1005424] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Accepted: 01/07/2016] [Indexed: 12/31/2022] Open
Abstract
Kaposi’s sarcoma herpesvirus (KSHV) causes Kaposi’s sarcoma and certain lymphoproliferative malignancies. Latent infection is established in the majority of tumor cells, whereas lytic replication is reactivated in a small fraction of cells, which is important for both virus spread and disease progression. A siRNA screen for novel regulators of KSHV reactivation identified the E3 ubiquitin ligase MDM2 as a negative regulator of viral reactivation. Depletion of MDM2, a repressor of p53, favored efficient activation of the viral lytic transcription program and viral reactivation. During lytic replication cells activated a p53 response, accumulated DNA damage and arrested at G2-phase. Depletion of p21, a p53 target gene, restored cell cycle progression and thereby impaired the virus reactivation cascade delaying the onset of virus replication induced cytopathic effect. Herpesviruses are known to reactivate in response to different kinds of stress, and our study now highlights the molecular events in the stressed host cell that KSHV has evolved to utilize to ensure efficient viral lytic replication. Herpesviruses are known to wake up and reactivate in response to different kinds of stress. Our study now highlights the key molecular host cell events that KSHV has evolved to utilize for efficient viral lytic replication: the activation of p53 and upregulation of p21, which slows down the cell cycle, but promotes viral replication and transcription of viral lytic genes. Mutations in TP53 gene are rarely found in KSHV-associated malignancies. Therefore, our work now provides a mechanistic explanation as to why the virus has evolved to retain p53.
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Affiliation(s)
- Giuseppe Balistreri
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Johanna Viiliäinen
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Mikko Turunen
- Genome-Scale Biology Program, Research Programs Unit and Department of Pathology, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Raquel Diaz
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Lauri Lyly
- Genome-Scale Biology Program, Research Programs Unit, University of Helsinki, Biomedicum Helsinki, Helsinki, Finland
| | - Pirita Pekkonen
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | | | - Krista Ojala
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Grzegorz Sarek
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Mari Teesalu
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Oxana Denisova
- Institute for Molecular Medicine (FIMM), University of Helsinki, Biomedicum Helsinki, Helsinki, Finland
| | - Karita Peltonen
- Centre for Drug Discovery, University of Helsinki, Helsinki, Finland
| | - Ilkka Julkunen
- Department of Virology, University of Turku and National Institute for Health and Welfare, Turku, Finland
| | - Markku Varjosalo
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
| | - Denis Kainov
- Institute for Molecular Medicine (FIMM), University of Helsinki, Biomedicum Helsinki, Helsinki, Finland
| | - Olli Kallioniemi
- Institute for Molecular Medicine (FIMM), University of Helsinki, Biomedicum Helsinki, Helsinki, Finland
| | - Marikki Laiho
- Centre for Drug Discovery, University of Helsinki, Helsinki, Finland
- Department of Radiation Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Jussi Taipale
- Genome-Scale Biology Program, Research Programs Unit and Department of Pathology, Haartman Institute, University of Helsinki, Helsinki, Finland
| | - Sampsa Hautaniemi
- Genome-Scale Biology Program, Research Programs Unit, University of Helsinki, Biomedicum Helsinki, Helsinki, Finland
| | - Päivi M. Ojala
- Translational Cancer Research Program, Research Programs Unit, University of Helsinki, Helsinki, Finland
- Foundation for the Finnish Cancer Institute, Helsinki, Finland
- Section of Virology, Division of Infectious Diseases, Department of Medicine, Imperial College London, London, United Kingdom
- * E-mail:
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21
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MDM2 E3 ligase-mediated ubiquitination and degradation of HDAC1 in vascular calcification. Nat Commun 2016; 7:10492. [PMID: 26832969 PMCID: PMC4740400 DOI: 10.1038/ncomms10492] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 12/04/2015] [Indexed: 12/15/2022] Open
Abstract
Vascular calcification (VC) is often associated with cardiovascular and metabolic diseases. However, the molecular mechanisms linking VC to these diseases have yet to be elucidated. Here we report that MDM2-induced ubiquitination of histone deacetylase 1 (HDAC1) mediates VC. Loss of HDAC1 activity via either chemical inhibitor or genetic ablation enhances VC. HDAC1 protein, but not mRNA, is reduced in cell and animal calcification models and in human calcified coronary artery. Under calcification-inducing conditions, proteasomal degradation of HDAC1 precedes VC and it is mediated by MDM2 E3 ubiquitin ligase that initiates HDAC1 K74 ubiquitination. Overexpression of MDM2 enhances VC, whereas loss of MDM2 blunts it. Decoy peptide spanning HDAC1 K74 and RG 7112, an MDM2 inhibitor, prevent VC in vivo and in vitro. These results uncover a previously unappreciated ubiquitination pathway and suggest MDM2-mediated HDAC1 ubiquitination as a new therapeutic target in VC. Vascular calcification (VC) increases morbidity and mortality in cardiovascular and metabolic diseases. Here, Kwon et al. show that calcification stimuli induce MDM2- mediated ubiquitination and proteasomal degradation of HDAC1, suggesting a possible therapeutic strategy for treatment of VC patients.
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Cytoplasmic isoforms of Kaposi sarcoma herpesvirus LANA recruit and antagonize the innate immune DNA sensor cGAS. Proc Natl Acad Sci U S A 2016; 113:E1034-43. [PMID: 26811480 DOI: 10.1073/pnas.1516812113] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The latency-associated nuclear antigen (LANA) of Kaposi sarcoma herpesvirus (KSHV) is mainly localized and functions in the nucleus of latently infected cells, playing a pivotal role in the replication and maintenance of latent viral episomal DNA. In addition, N-terminally truncated cytoplasmic isoforms of LANA, resulting from internal translation initiation, have been reported, but their function is unknown. Using coimmunoprecipitation and MS, we found the cGMP-AMP synthase (cGAS), an innate immune DNA sensor, to be a cellular interaction partner of cytoplasmic LANA isoforms. By directly binding to cGAS, LANA, and particularly, a cytoplasmic isoform, inhibit the cGAS-STING-dependent phosphorylation of TBK1 and IRF3 and thereby antagonize the cGAS-mediated restriction of KSHV lytic replication. We hypothesize that cytoplasmic forms of LANA, whose expression increases during lytic replication, inhibit cGAS to promote the reactivation of the KSHV from latency. This observation points to a novel function of the cytoplasmic isoforms of LANA during lytic replication and extends the function of LANA from its role during latency to the lytic replication cycle.
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Voon YL, Ahmad M, Wong PF, Husaini R, Ng WTW, Leong CO, Lane DP, Khoo ASB. Nutlin-3 sensitizes nasopharyngeal carcinoma cells to cisplatin-induced cytotoxicity. Oncol Rep 2015; 34:1692-700. [PMID: 26252575 PMCID: PMC4564086 DOI: 10.3892/or.2015.4177] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 06/29/2015] [Indexed: 11/24/2022] Open
Abstract
The small-molecule inhibitor of p53-Mdm2 interaction, Nutlin-3, is known to be effective against cancers expressing wild-type (wt) p53. p53 mutations are rare in nasopharyngeal carcinoma (NPC), hence targeting disruption of p53-Mdm2 interaction to reactivate p53 may offer a promising therapeutic strategy for NPC. In the present study, the effects of Nutlin-3 alone or in combination with cisplatin, a standard chemotherapeutic agent, were tested on C666-1 cells, an Epstein-Barr virus (EBV)-positive NPC cell line bearing wt p53. Treatment with Nutlin-3 activated the p53 pathway and sensitized NPC cells to the cytotoxic effects of cisplatin. The combined treatment also markedly suppressed soft agar colony growth formation and increased apoptosis of NPC cells. The effect of Nutlin-3 on NPC cells was inhibited by knockdown of p53, suggesting that its effect was p53-dependent. Extended treatment with increasing concentrations of Nutlin-3 did not result in emergence of p53 mutations in the C666-1 cells. Collectively, the present study revealed supportive evidence of the effectiveness of combining cisplatin and Nutlin-3 as a potential therapy against NPC.
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Affiliation(s)
- Yee-Lin Voon
- Molecular Pathology Unit, Cancer Research Centre, Institute for Medical Research, Kuala Lumpur 50588, Malaysia
| | - Munirah Ahmad
- Molecular Pathology Unit, Cancer Research Centre, Institute for Medical Research, Kuala Lumpur 50588, Malaysia
| | - Pooi-Fong Wong
- Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur 50603, Malaysia
| | - Roslina Husaini
- Molecular Pathology Unit, Cancer Research Centre, Institute for Medical Research, Kuala Lumpur 50588, Malaysia
| | - Wayne Tiong-Weng Ng
- Molecular Pathology Unit, Cancer Research Centre, Institute for Medical Research, Kuala Lumpur 50588, Malaysia
| | - Chee-Onn Leong
- School of Pharmacy and Health Sciences, International Medical University, Kuala Lumpur 57000, Malaysia
| | - David Philip Lane
- p53 Laboratory (p53Lab), Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Immunos, Singapore 138648, Republic of Singapore
| | - Alan Soo-Beng Khoo
- Molecular Pathology Unit, Cancer Research Centre, Institute for Medical Research, Kuala Lumpur 50588, Malaysia
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Structural proteins of Kaposi's sarcoma-associated herpesvirus antagonize p53-mediated apoptosis. Oncogene 2014; 34:639-49. [PMID: 24469037 DOI: 10.1038/onc.2013.595] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 11/15/2013] [Accepted: 12/13/2013] [Indexed: 01/10/2023]
Abstract
The tumor suppressor p53 is a central regulatory molecule of apoptosis and is commonly mutated in tumors. Kaposi's sarcoma-associated herpesvirus (KSHV)-related malignancies express wild-type p53. Accordingly, KSHV encodes proteins that counteract the cell death-inducing effects of p53. Here, the effects of all KSHV genes on the p53 signaling pathway were systematically analyzed using the reversely transfected cell microarray technology. With this approach we detected eight KSHV-encoded genes with potent p53 inhibiting activity in addition to the previously described inhibitory effects of KSHV genes ORF50, K10 and K10.5. Interestingly, the three most potent newly identified inhibitors were KSHV structural proteins, namely ORF22 (glycoprotein H), ORF25 (major capsid protein) and ORF64 (tegument protein). Validation of these results with a classical transfection approach showed that these proteins inhibited p53 signaling in a dose-dependent manner and that this effect could be reversed by small interfering RNA-mediated knockdown of the respective viral gene. All three genes inhibited p53-mediated apoptosis in response to Nutlin-3 treatment in non-infected and KSHV-infected cells. Addressing putative mechanisms, we could show that these proteins could also inhibit the transactivation of the promoters of apoptotic mediators of p53 such as BAX and PIG3. Altogether, we demonstrate for the first time that structural proteins of KSHV can counteract p53-induced apoptosis. These proteins are expressed in the late lytic phase of the viral life cycle and are incorporated into the KSHV virion. Accordingly, these genes may inhibit cell death in the productive and in the early entrance phase of KSHV infection.
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Radons J. Inflammatory stress and sarcomagenesis: a vicious interplay. Cell Stress Chaperones 2014; 19:1-13. [PMID: 24046208 PMCID: PMC3857425 DOI: 10.1007/s12192-013-0449-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 07/15/2013] [Accepted: 07/17/2013] [Indexed: 12/15/2022] Open
Abstract
Chronic inflammation represents one of the hallmarks of cancer, but its role in sarcomagenesis has long been overlooked. Sarcomas are a rare and heterogeneous group of tumors of mesenchymal origin accounting for less than 1 % of cancers in adults but 21 % of cancers in the pediatric population. Sarcomas are associated with bad prognosis, and their management requires a multidisciplinary team approach. Several lines of evidence indicate that inflammation has been implicated in sarcomagenesis leading to the activation of the key transcription factors HIF-1, NF- κB, and STAT-3 involved in a complex inflammatory network. In the past years, an increasing number of new targets have been identified in the treatment of sarcomas leading to the development of new drugs that aim to interrupt the vicious connection between inflammation and sarcomagenesis. This article makes a brief overview of preclinical and clinical evidence of the molecular pathways involved in the inflammatory stress response in sarcomagenesis and the most targeted therapies.
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Affiliation(s)
- Jürgen Radons
- multimmune GmbH c/o Department of Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Straße 22, 81675, Munich, Germany,
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26
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Radons J. The role of inflammation in sarcoma. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 816:259-313. [PMID: 24818727 DOI: 10.1007/978-3-0348-0837-8_11] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Sarcomas encompass a heterogenous group of tumors with diverse pathologically and clinically overlapping features. It is a rarely curable disease, and their management requires a multidisciplinary team approach. Chronic inflammation has emerged as one of the hallmarks of tumors including sarcomas. Classical inflammation-associated sarcomas comprise the inflammatory malignant fibrous histiocytoma and Kaposi sarcoma. The identification of specific chromosomal translocations and important intracellular signaling pathways such as Ras/Raf/MAPK, insulin-like growth factor, PI3K/AKT/mTOR, sonic hedgehog and Notch together with the increasing knowledge of angiogenesis has led to development of targeted therapies that aim to interrupt these pathways. Innovative agents like oncolytic viruses opened the way to design new therapeutic options with encouraging findings. Preclinical evidence also highlights the therapeutic potential of anti-inflammatory nutraceuticals as they can inhibit multiple pathways while being less toxic. This chapter gives an overview of actual therapeutic standards, newest evidence-based studies and exciting options for targeted therapies in sarcomas.
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Affiliation(s)
- Jürgen Radons
- Department of Radiotherapy and Radiation Oncology, Klinikum rechts der Isar, Technische Universität München, Ismaninger Straße 22, 81675, Munich, Germany,
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Amin M, Pantanowitz L. Review of latent and lytic phase biomarkers in Kaposi's sarcoma. ACTA ACUST UNITED AC 2013; 7:531-42. [PMID: 24070121 DOI: 10.1517/17530059.2013.842227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Kaposi's sarcoma (KS) is a vascular neoplasm with distinct clinical-epidemiological subtypes and varied clinical presentations. While the association of KS with human herpesvirus-8 (HHV8, KSHV) infection is well known, additional factors are needed for tumorigenesis. The precise sequence of events involved in KS development, progression and regression continues to be investigated. The discovery of KSHV biomarkers is helpful for diagnostic purposes, for understanding KS pathogenesis and for identifying potential druggable targets. AREAS COVERED This article reviews a number of key biomarkers relevant for the diagnosis of KS and HHV8-related pathogenesis. New developments in KS, potential therapeutic targets and the challenges involved in their discovery are highlighted. EXPERT OPINION Although there is currently no cure for KS, continued research devoted to uncovering biomarkers and understanding their pathogenic roles remains encouraging. The hope is that sometime soon one of these candidate targets will provide a curative therapy for this enigmatic sarcoma.
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Affiliation(s)
- Milon Amin
- University of Pittsburgh Medical Center, Department of Pathology , Suite 201, 5150 Centre Street, Pittsburgh , USA +1 412 794 4195 ; +1 412 794 3195 ;
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Katlama C, Deeks SG, Autran B, Martinez-Picado J, van Lunzen J, Rouzioux C, Miller M, Vella S, Schmitz JE, Ahlers J, Richman DD, Sekaly RP. Barriers to a cure for HIV: new ways to target and eradicate HIV-1 reservoirs. Lancet 2013; 381:2109-17. [PMID: 23541541 PMCID: PMC3815451 DOI: 10.1016/s0140-6736(13)60104-x] [Citation(s) in RCA: 240] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Antiretroviral therapy for HIV infection needs lifelong access and strict adherence to regimens that are both expensive and associated with toxic effects. A curative intervention will be needed to fully stop the epidemic. The failure to eradicate HIV infection during long-term antiretroviral therapy shows the intrinsic stability of the viral genome in latently infected CD4T cells and other cells, and possibly a sustained low-level viral replication. Heterogeneity in latently infected cell populations and homoeostatic proliferation of infected cells might affect the dynamics of virus production and persistence. Despite potent antiretroviral therapy, chronic immune activation, inflammation, and immune dysfunction persist, and are likely to have important effects on the size and distribution of the viral reservoir. The inability of the immune system to recognise cells harbouring latent virus and to eliminate cells actively producing virus is the biggest challenge to finding a cure. We look at new approaches to unravelling the complex virus-host interactions that lead to persistent infection and latency, and discuss the rationale for combination of novel treatment strategies with available antiretroviral treatment options to cure HIV.
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Affiliation(s)
- Christine Katlama
- Department of Infectious Diseases, Pierre et Marie Curie University, Pitié-Salpêtriere Hospital, Paris, France
| | - Steven G. Deeks
- Department of Medicine, University of California, San Francisco, CA, United States
| | - Brigitte Autran
- Laboratory Immunity and Infection, UMR-S 945, Pierre et Marie Curie University, Hospital Pitié-Salpêtriere, Paris, France
| | - Javier Martinez-Picado
- AIDS Research Institute Irsi Caixa, ICREA and Universitat Autònoma de Barcelona, Badalona, Barcelona, Spain
| | - Jan van Lunzen
- University Medical Center Eppendorf, Infectious Diseases Unit, Hamburg, Germany
| | - Christine Rouzioux
- Paris-Descartes University Necker Hospital, Department of Virology, Paris, France
| | - Michael Miller
- Department of West Point Discovery Chemistry, Merck Research Labs, West Point, USA
| | - Stefano Vella
- Department of Pharmacology and Therapeutic Research, Istituto Superiore di Sanità, Rome, Italy
| | - Joern E. Schmitz
- Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Jeffrey Ahlers
- Vaccine and Gene Therapy Institute of Florida, Port Saint Lucie, Florida, USA
| | - Douglas D. Richman
- VA San Diego Healthcare System and Departments of Pathology and Medicine, Center for AIDS Research, University of California, San Diego, California, USA
| | - Rafick P. Sekaly
- Vaccine and Gene Therapy Institute of Florida, Port Saint Lucie, Florida, USA
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Kaposi's sarcoma-associated herpesvirus induces rapid release of angiopoietin-2 from endothelial cells. J Virol 2013; 87:6326-35. [PMID: 23536671 DOI: 10.1128/jvi.03303-12] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Kaposi sarcoma-associated herpesvirus (KSHV) stimulates proliferation, angiogenesis, and inflammation to promote Kaposi sarcoma (KS) tumor growth, which involves various growth factors and cytokines. Previously, we found that KSHV infection of human umbilical vein endothelial cells (HUVECs) induces a transcriptional induction of the proangiogenic and proinflammatory cytokine angiopoietin-2 (Ang-2). Here, we report that KSHV induces rapid release of Ang-2 that is presynthesized and stored in the Weibel-Palade bodies (WPB) of endothelial cells upon binding to its integrin receptors. Blocking viral binding to integrins inhibits Ang-2 release. KSHV binding activates the integrin tyrosine kinase receptor signaling pathways, leading to tyrosine phosphorylation of focal adhesion kinase (FAK), the tyrosine kinase Src, and the Calα2 subunit of the l-type calcium channel to trigger rapid calcium (Ca(2+)) influx. Pretreatment of endothelial cells with specific inhibitors of protein tyrosine kinases inhibits KSHV-induced Ca(2+) influx and Ang-2 release. Inhibition of Ca(2+) mobilization with calcium channel blockers also inhibits Ang-2 release. Thus, the interaction between KSHV and its integrin receptors plays a key role in regulating rapid Ang-2 release from endothelial cells. This finding highlights a novel mechanism of viral induction of angiogenesis and inflammation, which might play important roles in the early event of KS tumor development.
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Hagemeier SR, Barlow EA, Meng Q, Kenney SC. The cellular ataxia telangiectasia-mutated kinase promotes epstein-barr virus lytic reactivation in response to multiple different types of lytic reactivation-inducing stimuli. J Virol 2012; 86:13360-70. [PMID: 23015717 PMCID: PMC3503132 DOI: 10.1128/jvi.01850-12] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Accepted: 09/20/2012] [Indexed: 12/22/2022] Open
Abstract
The Epstein-Barr virus (EBV) latent-to-lytic switch is mediated by the viral proteins BZLF1 (Z), BRLF1 (R), and BRRF1 (Na). Since we previously showed that DNA-damaging agents (including chemotherapy and irradiation) can induce EBV lytic reactivation and recently demonstrated that wild-type p53 contributes to lytic reactivation, we investigated the role of the ATM kinase during EBV reactivation. ATM phosphorylates and activates p53, as well as numerous other substrates involved in the cellular DNA damage response. Using an ATM inhibitor (KU55933), we found that ATM activity is required for efficient induction of EBV lytic gene expression by a variety of different stimuli, including a histone deacetylase (HDAC) inhibitor, the transforming growth factor β (TGF-β) cytokine, a demethylating agent (5-azacytidine), B cell receptor engagement with anti-IgG antibody, hydrogen peroxide, and the proteosome inhibitor bortezomib. In EBV-infected AGS (gastric) cells, knockdown of ATM, or p53, expression inhibits EBV reactivation. Conversely, treatment of these cells with nutlin-3 (which activates p53 and ATM) robustly induces lytic reactivation in a p53- and ATM-dependent manner. The ability of the EBV R and Na proteins to induce lytic reactivation in EBV-infected AGS cells is ATM dependent. However, overexpression of Z induces lytic gene expression in the presence or absence of ATM activity. Our results suggest that ATM enhances Z promoter activity in the context of the intact EBV genome and that p53 contributes to the ATM effect. Nevertheless, since we found that ATM inhibitors also reduce lytic reactivation in Burkitt lymphoma cells that have no p53, additional ATM substrates must also contribute to the ATM effect.
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Affiliation(s)
| | | | - Qiao Meng
- McArdle Laboratory for Cancer Research, Department of Oncology
| | - Shannon C. Kenney
- McArdle Laboratory for Cancer Research, Department of Oncology
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
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Kapoor S. The emerging anti-proliferative role of Nutlin-3 in the pathogenesis of systemic malignancies. Cancer Biol Ther 2012; 14:5. [PMID: 23114642 DOI: 10.4161/cbt.22629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Phosphorylation of the chromatin binding domain of KSHV LANA. PLoS Pathog 2012; 8:e1002972. [PMID: 23093938 PMCID: PMC3475679 DOI: 10.1371/journal.ppat.1002972] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 08/30/2012] [Indexed: 12/11/2022] Open
Abstract
The Kaposi sarcoma associated herpesvirus (KSHV) latency associated nuclear antigen (LANA) is expressed in all KSHV associated malignancies and is essential for maintenance of KSHV genomes in infected cells. To identify kinases that are potentially capable of modifying LANA, in vitro phosphorylation assays were performed using an Epstein Barr virus plus LANA protein microarray and 268 human kinases purified in active form from yeast. Interestingly, of the Epstein-Barr virus proteins on the array, the EBNA1 protein had the most similar kinase profile to LANA. We focused on nuclear kinases and on the N-terminus of LANA (amino acids 1–329) that contains the LANA chromatin binding domain. Sixty-three nuclear kinases phosphorylated the LANA N-terminus. Twenty-four nuclear kinases phosphorylated a peptide covering the LANA chromatin binding domain (amino acids 3–21). Alanine mutations of serine 10 and threonine 14 abolish or severely diminish chromatin and histone binding by LANA. However, conversion of these residues to the phosphomimetic glutamic acid restored histone binding suggesting that phosphorylation of serine 10 and threonine 14 may modulate LANA function. Serine 10 and threonine 14 were validated as substrates of casein kinase 1, PIM1, GSK-3 and RSK3 kinases. Short-term treatment of transfected cells with inhibitors of these kinases found that only RSK inhibition reduced LANA interaction with endogenous histone H2B. Extended treatment of PEL cell cultures with RSK inhibitor caused a decrease in LANA protein levels associated with p21 induction and a loss of PEL cell viability. The data indicate that RSK phosphorylation affects both LANA accumulation and function. The Kaposi sarcoma associated herpesvirus (KSHV) is associated with cancers that have an increased incidence in individuals with compromised immune systems. KSHV expresses a protein, LANA, that is needed to maintain KSHV genomes in infected cells and also promotes the growth of KSHV associated tumors. Kinases regulate protein function through phosphorylation. To identify kinases that may affect LANA function, we performed a screen in which 268 human kinases were isolated and tested for the ability to phosphorylate LANA in vitro. We focused on the region of LANA that contains the chromatin binding domain, a motif essential for tethering KSHV genomes to the cell chromatin and maintaining latent infection. We identified serine 10 and threonine 14 as amino acids within the chromatin binding domain whose phosphorylation was important for histone binding. Serine 10 and threonine 14 were targets of the CK1, PIM1, GSK-3 and RSK3 kinases. Treatment with an inhibitor of RSK kinase reduced LANA binding to histones, decreased LANA protein levels and caused a loss of KSHV infected PEL cell viability. Our experiments show that phosphorylation affects LANA function and suggest that KSHV infected cells may be particularly vulnerable to kinase inhibitors.
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