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Wang JCK, Baddock HT, Mafi A, Foe IT, Bratkowski M, Lin TY, Jensvold ZD, Preciado López M, Stokoe D, Eaton D, Hao Q, Nile AH. Structure of the p53 degradation complex from HPV16. Nat Commun 2024; 15:1842. [PMID: 38418456 PMCID: PMC10902388 DOI: 10.1038/s41467-024-45920-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 02/06/2024] [Indexed: 03/01/2024] Open
Abstract
Human papillomavirus (HPV) is a significant contributor to the global cancer burden, and its carcinogenic activity is facilitated in part by the HPV early protein 6 (E6), which interacts with the E3-ligase E6AP, also known as UBE3A, to promote degradation of the tumor suppressor, p53. In this study, we present a single-particle cryoEM structure of the full-length E6AP protein in complex with HPV16 E6 (16E6) and p53, determined at a resolution of ~3.3 Å. Our structure reveals extensive protein-protein interactions between 16E6 and E6AP, explaining their picomolar binding affinity. These findings shed light on the molecular basis of the ternary complex, which has been pursued as a potential therapeutic target for HPV-driven cervical, anal, and oropharyngeal cancers over the last two decades. Understanding the structural and mechanistic underpinnings of this complex is crucial for developing effective therapies to combat HPV-induced cancers. Our findings may help to explain why previous attempts to disrupt this complex have failed to generate therapeutic modalities and suggest that current strategies should be reevaluated.
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Affiliation(s)
- John C K Wang
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | - Hannah T Baddock
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | - Amirhossein Mafi
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | - Ian T Foe
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | - Matthew Bratkowski
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | - Ting-Yu Lin
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | - Zena D Jensvold
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | | | - David Stokoe
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | - Dan Eaton
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA
| | - Qi Hao
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA.
| | - Aaron H Nile
- Calico Life Sciences LLC, 1170 Veterans Blvd, South San Francisco, CA, 94080, USA.
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2
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Vemula V, Marudamuthu AS, Prasad S, B M S, S E M, A S, Seal P, Alagumuthu M. Fragment-based design and MD simulations of human papilloma virus-16 E6 protein inhibitors. J Biomol Struct Dyn 2024; 42:288-297. [PMID: 37098806 DOI: 10.1080/07391102.2023.2203775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 03/10/2023] [Indexed: 04/27/2023]
Abstract
The main objective of this study is to screen potential small molecule inhibitors against HPV (Human Papilloma Virus)-16 E6 protein (HPV16 E6P) using a fragment-based approach. Twenty-six natural HPV inhibitors were selected based on the review of the literature. Among them, Luteolin was selected as the reference compound. These 26 compounds were used to generate novel inhibitors against HPV16 E6P. Fragment script and BREED of Schrodinger software were used to build novel inhibitor molecules. The result in 817 novel molecules was docked into the active binding site of HPV E6 protein and the top ten compounds were screened based on binding affinity compared to Luteolin for further study. Compounds Cpd5, Cpd7, and Cpd10 were the most potent inhibitors of HPV16 E6P and these were non-toxic and showed high Gastrointestinal (GI) absorption and positive drug-likeness score. Complexes of these compounds were stable in the 200 ns Molecular Dynamics (MD) simulation. These 3 HPV16 E6P inhibitors could be the lead molecules as new drugs for HPV-related diseases.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Vani Vemula
- Department of Microbiology, M. S. Ramaiah College of Arts, Science and Commerce, Bengaluru, India
| | | | - Sanjay Prasad
- Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengaluru, India
| | - Suman B M
- Department of Microbiology, M. S. Ramaiah College of Arts, Science and Commerce, Bengaluru, India
| | - Mamatha S E
- Department of Microbiology, M. S. Ramaiah College of Arts, Science and Commerce, Bengaluru, India
| | - Swathi A
- Department of Microbiology, M. S. Ramaiah College of Arts, Science and Commerce, Bengaluru, India
| | - Priyanka Seal
- Department of Microbiology, M. S. Ramaiah College of Arts, Science and Commerce, Bengaluru, India
| | - Manikandan Alagumuthu
- Department of Microbiology, M. S. Ramaiah College of Arts, Science and Commerce, Bengaluru, India
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3
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Zebardast A, Latifi T, shirzad M, Goodarzi G, Ebrahimi Fana S, Samavarchi Tehrani S, Yahyapour Y. Critical involvement of circular RNAs in virus-associated cancers. Genes Dis 2023; 10:2296-2305. [PMID: 37554189 PMCID: PMC10404876 DOI: 10.1016/j.gendis.2022.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 03/25/2022] [Accepted: 04/06/2022] [Indexed: 12/09/2022] Open
Abstract
Virus-related cancer is cancer where viral infection leads to the malignant transformation of the host's infected cells. Seven viruses (e.g., human papillomavirus (HPV), Epstein-Barr virus (EBV), Kaposi's sarcoma herpesvirus (KSHV), Hepatitis B virus (HBV), Hepatitis C virus (HCV), Human T-lymphotropic virus (HTLV), and Merkel cell polyomavirus (MCV)) that infect humans have been identified as an oncogene and have been associated with several human malignancies. Recently, growing attention has been attracted to exploring the pathogenesis of virus-related cancers. One of the most mysterious molecules involved in carcinogenesis and progression of virus-related cancers is circular RNAs (circRNA). These emerging non-coding RNAs (ncRNAs), due to the absence of 5' and 3' ends, have high stability than linear RNAs and are found in some species across the eukaryotic organisms. Compelling evidence has revealed that viruses also encode a repertoire of circRNAs, as well as dysregulation of these viral circRNAs play a critical role in the pathogenesis and progression of different types of virus-related cancers. Therefore, understanding the exact role and function of the virally encoded circRNAs with virus-associated cancers will open a new road for increasing our knowledge about the RNA world. Hence, in this review, we will focus on emerging roles of virus-encoded circRNAs in multiple cancers, including cervical cancer, gastric cancer, Merkel cell carcinoma, nasopharyngeal carcinoma, Kaposi cancer, and liver cancer.
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Affiliation(s)
- Arghavan Zebardast
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran 1417613151, Iran
| | - Tayebeh Latifi
- Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran 1417613151, Iran
| | - Moein shirzad
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol 47176, Iran
| | - Golnaz Goodarzi
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran 1417613151, Iran
- Student Scientific Research Center, Tehran University of Medical Sciences, Tehran 1417613151, Iran
| | - Saeed Ebrahimi Fana
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran 1417613151, Iran
- Student Scientific Research Center, Tehran University of Medical Sciences, Tehran 1417613151, Iran
| | - Sadra Samavarchi Tehrani
- Department of Clinical Biochemistry, School of Medicine, Tehran University of Medical Sciences, Tehran 1417613151, Iran
- Student Scientific Research Center, Tehran University of Medical Sciences, Tehran 1417613151, Iran
| | - Yousef Yahyapour
- Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol 47176, Iran
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4
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Billingsley CL, Chintala S, Katzenellenbogen RA. Post-Transcriptional Gene Regulation by HPV 16E6 and Its Host Protein Partners. Viruses 2022; 14:1483. [PMID: 35891463 PMCID: PMC9315527 DOI: 10.3390/v14071483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/01/2022] [Accepted: 07/01/2022] [Indexed: 12/10/2022] Open
Abstract
Human papillomavirus type 16 (HPV 16) is the most common oncogenic type of HPV in cervical, anogenital, and head and neck cancers, making HPV 16 an important high-risk HPV (HR HPV) type. To create an environment permissible for viral maintenance and growth and to initiate and support oncogenesis, the HR HPV protein E6 functions to dysregulate normal cellular processes. HR HPV type 16 E6 (16E6) has previously been shown to bind cellular proteins in order to transcriptionally activate genes and to target regulatory proteins for degradation. We have identified an additional functional model for 16E6. First, 16E6 binds to cellular RNA processing and binding proteins, specifically cytoplasmic poly(A) binding proteins (PABPCs) and NFX1-123. Then, 16E6 hijacks those proteins' functions to post-transcriptionally regulate cellular immortalization, growth, and differentiation genes and pathways in keratinocytes. In this review, we have highlighted studies that introduce this new model of 16E6 functionality. Understanding ways in which HR HPV dysregulates cellular processes-particularly at the level of post-transcriptional gene regulation-presents new ways to consider mechanisms underlying DNA tumor virus function and new areas for therapeutic target development in HPV-associated cancers.
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Affiliation(s)
- Caylin L. Billingsley
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (C.L.B.); (S.C.)
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Sreenivasulu Chintala
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (C.L.B.); (S.C.)
| | - Rachel A. Katzenellenbogen
- Herman B Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (C.L.B.); (S.C.)
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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5
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Song L, Mao R, Ding L, Tian Z, Zhang M, Wang J, Wang M, Lyu Y, Liu C, Feng M, Jia H, Wang J. hnRNP E1 Regulates HPV16 Oncogene Expression and Inhibits Cervical Cancerization. Front Oncol 2022; 12:905900. [PMID: 35800060 PMCID: PMC9253288 DOI: 10.3389/fonc.2022.905900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/24/2022] [Indexed: 11/15/2022] Open
Abstract
hnRNP E1 (heterogeneous nuclear ribonucleoprotein E1) is an important RNA-binding protein (RBPs) that plays a vital role in tumor development. Human papillomavirus 16 (HPV16) contains numerous sites that can bind to RNA/DNA and may be modified by multiple RBPs, which contribute to HPV gene expression and HPV-associated cancer development. However, the effects of hnRNP E1 on HPV16 oncogenes in the development of cervical lesions remain unclear. A total of 816 participants with different grades of cervical lesions were enrolled in a community-based cohort established in Shanxi Province, China. The Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were used to analyze the association between hnRNP E1 mRNA expression and cervical lesions. Cells with up_ and down_regulated hnRNP E1 were established. hnRNP E1 functions were evaluated using cell counting kit-8, flow cytometry analyses, and chromatin immunoprecipitation sequencing. Our results showed that hnRNP E1 expression was linearly dependent on the severity of the cervical lesions. Low expression of HPV16 E2, high expression of E6, and a low ratio of E2 to E6 could increase the risk of cervical lesions. hnRNP E1 expression was correlated with HPV16 oncogene expression. hnRNP E1-relevant genes were involved in the dopaminergic synapses, Wnt signaling pathway, gnRH secretion, and mTOR signaling pathway. hnRNP E1 significantly inhibited cell proliferation, induced apoptosis, arrested the cell cycle at the G0/G1 stage, and decreased HPV16 E6 expression. Our results indicate that hnRNP E1 could downregulate HPV16 E6 oncogene expression and inhibit cervical cancerization, which sheds new light on preventing the carcinogenicity of HPV across a range of diseases by regulating RNA-binding proteins.
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Affiliation(s)
- Li Song
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Rui Mao
- Questrom School of Business, Boston University, Boston, MA, United States
| | - Ling Ding
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Zhiqiang Tian
- Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, China
- Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Mingxuan Zhang
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Jiahao Wang
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Ming Wang
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Yuanjing Lyu
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Chunliang Liu
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Meijuan Feng
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Haixia Jia
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
| | - Jintao Wang
- Department of Epidemiology, School of Public Health, Shanxi Medical University, Taiyuan, China
- *Correspondence: Jintao Wang,
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6
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Haręża DA, Wilczyński JR, Paradowska E. Human Papillomaviruses as Infectious Agents in Gynecological Cancers―Oncogenic Properties of Viral Proteins. Int J Mol Sci 2022; 23:ijms23031818. [PMID: 35163748 PMCID: PMC8836588 DOI: 10.3390/ijms23031818] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/29/2022] [Accepted: 02/03/2022] [Indexed: 01/25/2023] Open
Abstract
Human papillomaviruses (HPVs), which belong to the Papillomaviridae family, constitute a group of small nonenveloped double-stranded DNA viruses. HPV has a small genome that only encodes a few proteins, and it is also responsible for 5% of all human cancers, including cervical, vaginal, vulvar, penile, anal, and oropharyngeal cancers. HPV types may be classified as high- and low-risk genotypes (HR-HPVs and LR-HPVs, respectively) according to their oncogenic potential. HR-HPV 16 and 18 are the most common types worldwide and are the primary types that are responsible for most HPV-related cancers. The activity of the viral E6 and E7 oncoproteins, which interfere with critical cell cycle points such as suppressive tumor protein p53 (p53) and retinoblastoma protein (pRB), is the major contributor to HPV-induced neoplastic initiation and progression of carcinogenesis. In addition, the E5 protein might also play a significant role in tumorigenesis. The role of HPV in the pathogenesis of gynecological cancers is still not fully understood, which indicates a wide spectrum of potential research areas. This review focuses on HPV biology, the distribution of HPVs in gynecological cancers, the properties of viral oncoproteins, and the molecular mechanisms of carcinogenesis.
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Affiliation(s)
- Daria A. Haręża
- Laboratory of Virology, Institute of Medical Biology of the Polish Academy of Sciences, 93-232 Lodz, Poland;
- BioMedChem Doctoral School of the University of Lodz and Lodz Institutes of the Polish Academy of Sciences, 90-237 Lodz, Poland
| | - Jacek R. Wilczyński
- Department of Surgical and Oncological Gynecology, Medical University of Lodz, 90-419 Lodz, Poland;
| | - Edyta Paradowska
- Laboratory of Virology, Institute of Medical Biology of the Polish Academy of Sciences, 93-232 Lodz, Poland;
- Correspondence: ; Tel.: +48-42-272-3629; Fax: +48-42-272-3630
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7
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Varna D, Geromichalou E, Papachristou E, Papi R, Hatzidimitriou AG, Panteris E, Psomas G, Geromichalos GD, Aslanidis P, Choli-Papadopoulou T, Angaridis PA. Biocompatible silver(I) complexes with heterocyclic thioamide ligands for selective killing of cancer cells and high antimicrobial activity - A combined in vitro and in silico study. J Inorg Biochem 2021; 228:111695. [PMID: 35007963 DOI: 10.1016/j.jinorgbio.2021.111695] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/02/2021] [Accepted: 12/23/2021] [Indexed: 12/11/2022]
Abstract
A series of heteroleptic Ag(I) complexes bearing 4,6-dimethyl-2-pyrimidinethiol (dmp2SH), i.e., [AgCl(dmp2SH)(PPh3)2] (1), [Ag(dmp2SH)(PPh3)2]NO3 (2), [Ag(dmp2SΗ)(xantphos)]NO3 (3), [Ag(μ-dmp2S)(PPh3)]2 (4), [Ag(dmp2S)(xantphos)] (5), [Ag(μ-dmp2S)(DPEphos)]2 (6) (xantphos = 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene and DPEPhos = bis[(2-diphenylphosphino)phenyl]ether) were synthesized. The complexes display systematic variation of particular structural characteristics which were proved to have a significant impact on their in vitro cytotoxicity and antimicrobial properties. A moderate-to-high potential for bacteria growth inhibition was observed for all complexes, with 2, 3 and 5 being particularly effective against Gram-(+) bacteria (IC50 = 1.6-4.5 μM). The three complexes exhibit high in vitro cytotoxicity against HeLa and MCF-7 cancer cells (IC50 = 0.32-3.00 μΜ), suggesting the importance of coordination unsaturation and cationic charge for effective bioactivity. A very low cytotoxicity against HDFa normal cells was observed, revealing a high degree of selectivity (selectivity index ~10) and, hence, biocompatibility. Fluorescence microscopy using 2 showed effective targeting on the membrane of the HeLa cancer cells, subsequently inducing cell death. Binding of the complexes to serum albumin proteins is reasonably strong for potential uptake and subsequent release to target sites. A moderate in vitro antioxidant capacity for free radicals scavenging was observed and a low potential to destroy the double-strand structure of calf-thymus DNA by intercalation, suggesting likely implication of these properties in the bioactivity mechanisms of these complexes. Further insight into possible mechanisms of bioactivity was obtained by molecular modeling calculations, by exploring their ability to act as potential inhibitors of DNA-gyrase, human estrogen receptor alpha, human cyclin-dependent kinase 6, and human papillomavirus E6 oncoprotein.
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Affiliation(s)
- Despoina Varna
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Elena Geromichalou
- Laboratory of Pharmacology, Medical School, National and Kapodistrian University of Athens, 75 Mikras Asias Street, Athens 11527, Greece
| | - Eleni Papachristou
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Rigini Papi
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Antonios G Hatzidimitriou
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Emmanuel Panteris
- Laboratory of Botany, Department of Biology, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - George Psomas
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - George D Geromichalos
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Paraskevas Aslanidis
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Theodora Choli-Papadopoulou
- Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
| | - Panagiotis A Angaridis
- Laboratory of Inorganic Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
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Marongiu L, Allgayer H. Viruses in colorectal cancer. Mol Oncol 2021; 16:1423-1450. [PMID: 34514694 PMCID: PMC8978519 DOI: 10.1002/1878-0261.13100] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 07/15/2021] [Accepted: 09/10/2021] [Indexed: 12/23/2022] Open
Abstract
Increasing evidence suggests that microorganisms might represent at least highly interesting cofactors in colorectal cancer (CRC) oncogenesis and progression. Still, associated mechanisms, specifically in colonocytes and their microenvironmental interactions, are still poorly understood. Although, currently, at least seven viruses are being recognized as human carcinogens, only three of these – Epstein–Barr virus (EBV), human papillomavirus (HPV) and John Cunningham virus (JCV) – have been described, with varying levels of evidence, in CRC. In addition, cytomegalovirus (CMV) has been associated with CRC in some publications, albeit not being a fully acknowledged oncovirus. Moreover, recent microbiome studies set increasing grounds for new hypotheses on bacteriophages as interesting additional modulators in CRC carcinogenesis and progression. The present Review summarizes how particular groups of viruses, including bacteriophages, affect cells and the cellular and microbial microenvironment, thereby putatively contributing to foster CRC. This could be achieved, for example, by promoting several processes – such as DNA damage, chromosomal instability, or molecular aspects of cell proliferation, CRC progression and metastasis – not necessarily by direct infection of epithelial cells only, but also by interaction with the microenvironment of infected cells. In this context, there are striking common features of EBV, CMV, HPV and JCV that are able to promote oncogenesis, in terms of establishing latent infections and affecting p53‐/pRb‐driven, epithelial–mesenchymal transition (EMT)‐/EGFR‐associated and especially Wnt/β‐catenin‐driven pathways. We speculate that, at least in part, such viral impacts on particular pathways might be reflected in lasting (e.g. mutational or further genomic) fingerprints of viruses in cells. Also, the complex interplay between several species within the intestinal microbiome, involving a direct or indirect impact on colorectal and microenvironmental cells but also between, for example, phages and bacterial and viral pathogens, and further novel species certainly might, in part, explain ongoing difficulties to establish unequivocal monocausal links between specific viral infections and CRC.
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Affiliation(s)
- Luigi Marongiu
- Department of Experimental Surgery - Cancer Metastasis, Medical Faculty Mannheim, Ruprecht-Karls-University of Heidelberg, Mannheim, Germany
| | - Heike Allgayer
- Department of Experimental Surgery - Cancer Metastasis, Medical Faculty Mannheim, Ruprecht-Karls-University of Heidelberg, Mannheim, Germany
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HPV Status and Individual Characteristics of Human Papillomavirus Infection as Predictors for Clinical Outcome of Locally Advanced Cervical Cancer. J Pers Med 2021; 11:jpm11060479. [PMID: 34071821 PMCID: PMC8227948 DOI: 10.3390/jpm11060479] [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: 04/30/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 01/08/2023] Open
Abstract
This study is aimed at searching for an informative predictor of the clinical outcome of cervical cancer (CC) patients. The study included 135 patients with locally advanced cervical cancer (FIGO stage II-III) associated with human papillomavirus (HPV) 16/18 types or negative status of HPV infection. Using logistic regression, we analyzed the influence of the treatment method, clinical and morphological characteristics, and the molecular genetic parameters of HPV on the disease free survival (DFS) of patients treated with radiotherapy or chemoradiotherapy. Multivariate analysis revealed three factors that have prognostic significance for DFS, i.e., HPV-related biomarker (HPV-negativity or HPV DNA integration into the cell genome) (OR = 9.67, p = 1.2 × 10-4), stage of the disease (OR = 4.69, p = 0.001) and age (OR = 0.61, p = 0.025). The predictive model has a high statistical significance (p = 5.0 × 10-8; Nagelkirk's R2 = 0.336), as well as sensitivity (Se = 0.74) and specificity (Sp = 0.75). Thus, simultaneous accounting for the clinical and molecular genetic predictors (stage of the disease, patient age and HPV-related biomarker) makes it possible to effectively differentiate patients with prognostically favorable and unfavorable outcome of the disease.
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10
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Radiation Response of Cervical Cancer Stem Cells Is Associated with Pretreatment Proportion of These Cells and Physical Status of HPV DNA. Int J Mol Sci 2021; 22:ijms22031445. [PMID: 33535561 PMCID: PMC7867083 DOI: 10.3390/ijms22031445] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 01/24/2021] [Accepted: 01/28/2021] [Indexed: 12/17/2022] Open
Abstract
Radio- and chemoresistance of cancer stem cells (CSCs) is considered as one of the possible causes of adverse results of chemoradiotherapy for various malignancies, including cervical cancer. However, little is known about quantitative changes in the CSC subpopulation in the course of treatment and mechanisms for individual response of CSCs to therapy. The purpose of the study was to evaluate the association of radiation response of cervical CSCs with clinical and morphological parameters of disease and features of human papillomavirus (HPV) infection. The proportion of CD44+CD24low CSCs was determined by flow cytometry in cervical scrapings from 55 patients with squamous cell carcinoma of uterine cervix before treatment and after fractionated irradiation at a total dose of 10 Gy. Real-time PCR assay was used to evaluate molecular parameters of HPV DNA. Post-radiation increase in the CSC proportion was found in 47.3% of patients. Clinical and morphological parameters (stage, status of lymph node involvement, and histological type) were not significantly correlated with radiation changes in the CSC proportion. Single- and multifactor analyses revealed two independent indicators affecting the radiation response of CSCs: initial proportion of CSCs and physical status of HPV DNA (R = 0.86, p = 0.001 for the multiple regression model in the whole).
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11
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Zamulaeva IA, Selivanova EI, Kiseleva VI, Matchuk ON, Krikunova LI, Mkrtchyan LS, Kaprin AD. Correlation of Radiation Response of Cervical Cancer Stem Cells with Their Initial Number before Treatment and Molecular Genetic Features of Papillomavirus Infection. Bull Exp Biol Med 2020; 170:241-245. [PMID: 33263849 DOI: 10.1007/s10517-020-05043-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Indexed: 12/27/2022]
Abstract
The proportion of CD44+CD24low cancer stem cells (CSC) was determined in cervical scrapings of 41 patients with squamous cell carcinoma of the uterine cervix before treatment and after irradiation in a total focal dose of 10 Gy. The relationship of quantitative changes in the CSC population with such parameters of papillomavirus infection as genotype, viral load, and physical status of HPV DNA (the absence or presence of HPV DNA integration into the cell genome and the degree of integration) was studied. Single- and multi-factor analysis revealed 2 independent indicators affecting the radiation response of CSC: initial number of these cells before treatment and physical status of HPV DNA. The increase in the CSC proportion after radiation exposure was observed 4.5-fold more often in patients with an initially low proportion of CSC (<3%) than that in other patients (p=0.001). The CSC proportion increased by on average 3% after irradiation in patients with complete integration of HPV 16/18 DNA and decreased by 3.8 % in patients with partial integration or no integration (p=0.03).
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Affiliation(s)
- I A Zamulaeva
- A. F. Tsyb Medical Radiological Research Center - Affiliated Branch of National Medical Research Centre of Radiology, Ministry of Health of the Russian Federation, Obninsk, Russia.
| | - E I Selivanova
- A. F. Tsyb Medical Radiological Research Center - Affiliated Branch of National Medical Research Centre of Radiology, Ministry of Health of the Russian Federation, Obninsk, Russia
| | - V I Kiseleva
- A. F. Tsyb Medical Radiological Research Center - Affiliated Branch of National Medical Research Centre of Radiology, Ministry of Health of the Russian Federation, Obninsk, Russia
| | - O N Matchuk
- A. F. Tsyb Medical Radiological Research Center - Affiliated Branch of National Medical Research Centre of Radiology, Ministry of Health of the Russian Federation, Obninsk, Russia
| | - L I Krikunova
- A. F. Tsyb Medical Radiological Research Center - Affiliated Branch of National Medical Research Centre of Radiology, Ministry of Health of the Russian Federation, Obninsk, Russia
| | - L S Mkrtchyan
- A. F. Tsyb Medical Radiological Research Center - Affiliated Branch of National Medical Research Centre of Radiology, Ministry of Health of the Russian Federation, Obninsk, Russia
| | - A D Kaprin
- A. F. Tsyb Medical Radiological Research Center - Affiliated Branch of National Medical Research Centre of Radiology, Ministry of Health of the Russian Federation, Obninsk, Russia
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12
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The human papillomavirus E6 protein targets apoptosis-inducing factor (AIF) for degradation. Sci Rep 2020; 10:14195. [PMID: 32848167 PMCID: PMC7450093 DOI: 10.1038/s41598-020-71134-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Accepted: 08/07/2020] [Indexed: 12/13/2022] Open
Abstract
Oncoprotein E6 of high-risk human papillomavirus (HPV) plays a critical role in inducing cell immortalization and malignancy. E6 downregulates caspase-dependent pathway through the degradation of p53. However, the effect of HPV E6 on other pathways is still under investigation. In the present study, we found that HPV E6 directly binds to all three forms (precursor, mature, and apoptotic) of apoptosis-inducing factor (AIF) and co-localizes with apoptotic AIF. This binding induced MG132-sensitive reduction of AIF expression in the presence of E6 derived from HPV16 (16E6), a cancer-causing type of HPV. Conversely, E6 derived from a non-cancer-causing type of HPV, HPV6 (6E6), did not reduce the levels of AIF despite its interaction with AIF. Flow cytometric analysis revealed that 16E6, but not 6E6, suppressed apoptotic AIF-induced chromatin degradation (an indicator of caspase-independent apoptosis) and staurosporine (STS, a protein kinase inhibitor)-induced apoptosis. AIF knockdown reduced STS-induced apoptosis in both of 16E6-expressing and 6E6-expressing cells; however, the reduction in 16E6-expressing cells was lower than that in 6E6-expressing cells. These findings indicate that 16E6, but not 6E6, blocks AIF-mediated apoptosis, and that AIF may represent a novel therapeutic target for HPV-induced cervical cancer.
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13
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Subversion of Host Innate Immunity by Human Papillomavirus Oncoproteins. Pathogens 2020; 9:pathogens9040292. [PMID: 32316236 PMCID: PMC7238203 DOI: 10.3390/pathogens9040292] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 12/19/2022] Open
Abstract
The growth of human papillomavirus (HPV)-transformed cells depends on the ability of the viral oncoproteins E6 and E7, especially those from high-risk HPV16/18, to manipulate the signaling pathways involved in cell proliferation, cell death, and innate immunity. Emerging evidence indicates that E6/E7 inhibition reactivates the host innate immune response, reversing what until then was an unresponsive cellular state suitable for viral persistence and tumorigenesis. Given that the disruption of distinct mechanisms of immune evasion is an attractive strategy for cancer therapy, the race is on to gain a better understanding of E6/E7-induced immune escape and cancer progression. Here, we review recent literature on the interplay between E6/E7 and the innate immune signaling pathways cGAS/STING/TBK1, RIG-I/MAVS/TBK1, and Toll-like receptors (TLRs). The overall emerging picture is that E6 and E7 have evolved broad-spectrum mechanisms allowing for the simultaneous depletion of multiple rather than single innate immunity effectors. The cGAS/STING/TBK1 pathway appears to be the most heavily impacted, whereas the RIG-I/MAVS/TBK1, still partially functional in HPV-transformed cells, can be activated by the powerful RIG-I agonist M8, triggering the massive production of type I and III interferons (IFNs), which potentiates chemotherapy-mediated cell killing. Overall, the identification of novel therapeutic targets to restore the innate immune response in HPV-transformed cells could transform the way HPV-associated cancers are treated.
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14
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Amacher JF, Brooks L, Hampton TH, Madden DR. Specificity in PDZ-peptide interaction networks: Computational analysis and review. JOURNAL OF STRUCTURAL BIOLOGY-X 2020; 4:100022. [PMID: 32289118 PMCID: PMC7138185 DOI: 10.1016/j.yjsbx.2020.100022] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/26/2020] [Accepted: 02/29/2020] [Indexed: 01/03/2023]
Abstract
Globular PDZ domains typically serve as protein-protein interaction modules that regulate a wide variety of cellular functions via recognition of short linear motifs (SLiMs). Often, PDZ mediated-interactions are essential components of macromolecular complexes, and disruption affects the entire scaffold. Due to their roles as linchpins in trafficking and signaling pathways, PDZ domains are attractive targets: both for controlling viral pathogens, which bind PDZ domains and hijack cellular machinery, as well as for developing therapies to combat human disease. However, successful therapeutic interventions that avoid off-target effects are a challenge, because each PDZ domain interacts with a number of cellular targets, and specific binding preferences can be difficult to decipher. Over twenty-five years of research has produced a wealth of data on the stereochemical preferences of individual PDZ proteins and their binding partners. Currently the field lacks a central repository for this information. Here, we provide this important resource and provide a manually curated, comprehensive list of the 271 human PDZ domains. We use individual domain, as well as recent genomic and proteomic, data in order to gain a holistic view of PDZ domains and interaction networks, arguing this knowledge is critical to optimize targeting selectivity and to benefit human health.
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Affiliation(s)
- Jeanine F Amacher
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA.,Department of Chemistry, Western Washington University, Bellingham, WA 98225, USA
| | - Lionel Brooks
- Department of Biology, Western Washington University, Bellingham, WA 98225, USA
| | - Thomas H Hampton
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
| | - Dean R Madden
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA
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15
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Identification of potential binding pocket on viral oncoprotein HPV16 E6: a promising anti-cancer target for small molecule drug discovery. BMC Mol Cell Biol 2019; 20:30. [PMID: 31387520 PMCID: PMC6685234 DOI: 10.1186/s12860-019-0214-3] [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: 06/03/2019] [Accepted: 07/23/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Several human cancers, especially cervical cancer are caused by the infection of high risk strains of human papillomaviruses (HPV), notably HPV16. It is implicated that the oncoprotein E6 expressed from HPV, is inhibiting the apoptotic pathway by binding to adaptor molecule FADD (Fas-associated death domain). Inhibiting E6 interactions with FADD could provide a promising treatment for cervical cancer. There are few small molecules reported to inhibit such interactions. However, the FADD binding site information on the HPV E6 is not currently available. This binding site information may provide an opportunity to design new small molecule inhibitors to treat E6 mediated cancers. In this study we report the possible binding pocket on HPV16 E6 oncoprotein by using activity data of reported inhibitors through a stepwise molecular modeling approach. RESULTS Blind docking and removing duplicates followed by visual inspection to determine ligand-receptor interactions provided 68 possible binding sites on the E6 protein. Individual docking of all known inhibitors lead to the identification of 28 pockets having some kind of correlation with their activity data. It was also observed that several of these pockets overlapped with each other, having some amino acids in common. Amino acids Leu50 and Cys51 were identified as key E6 residues for high affinity ligand binding which are seen in most of these pockets. In most cases, ligands demonstrated a hydrogen bond interaction with Cys51. Ala61, Arg131 and Gln107 were also frequently observed showing interactions among these pockets. A few amino acids unique to each ligand were also identified representing additional interactions at the receptor site. CONCLUSIONS After determining receptor-ligand interactions between E6 oncoprotein and the six known inhibitors, the amino acids Cys51, Leu50, Arg102, Arg131, Leu67, Val62, and Gln107 were identified to have importance in E6 inhibition. It was generally observed that Leu50 and Cys51 are necessary for high binding affinity with Cys51 being essential for hydrogen bonding. This study identified a potential binding pocket for the E6 inhibitors. Identification of the ligand binding pocket helps to design novel inhibitors of HPV16 E6 oncoprotein as a promising treatment for cervical cancer.
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16
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da Cruz Silva LL, de Oliveira WRP, Sotto MN. Epidermodysplasia verruciformis: revision of a model of carcinogenic disease. SURGICAL AND EXPERIMENTAL PATHOLOGY 2019. [DOI: 10.1186/s42047-019-0046-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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17
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The PDZ-Binding Motif of HPV16-E6 Oncoprotein Modulates the Keratinization and Stemness Transcriptional Profile In Vivo. BIOMED RESEARCH INTERNATIONAL 2017; 2017:7868645. [PMID: 29130045 PMCID: PMC5654334 DOI: 10.1155/2017/7868645] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/24/2017] [Accepted: 08/24/2017] [Indexed: 11/23/2022]
Abstract
Objective The aim of this work was to compare the early gene expression profiles in the skin of HPV16-E6 transgenic mice regulated by the E6 PDZ-binding motif. Materials and Methods The global transcriptional profiles in dorsal skin biopsies from K14E6 and K14E6Δ146-151 transgenic mice were compared using microarrays. Relevant genes obtained from the most differentially expressed processes were further examined by RT-qPCR, in situ RT-PCR, Western blot, or immunofluorescence. Results The transcriptomic landscape of K14E6 versus K14E6Δ146-151 shows that the most affected expression profiles were those related to keratinocyte differentiation, stem cell maintenance, and keratinization. Additionally, downregulation of epidermal stemness markers such as K15 and CD34, as well as the upregulation of cytokeratin 6b, appeared to be dependent on the E6 PDZ-binding motif. Finally, wound healing, a physiological process linked to stemness, is impaired in the K14E6 mice compared to K14E6Δ146-151. Conclusion The E6 PDZ-binding motif appears to affect stemness and keratinization during early stages of skin carcinogenesis. As E6 plays a significant role in HPV-induced skin carcinogenesis, the K14E6 versus K14E6Δ146-151 transcriptional profile provides a source of valuable data to uncover novel E6 functions in the skin.
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18
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Ronchi VP, Kim ED, Summa CM, Klein JM, Haas AL. In silico modeling of the cryptic E2∼ubiquitin-binding site of E6-associated protein (E6AP)/UBE3A reveals the mechanism of polyubiquitin chain assembly. J Biol Chem 2017; 292:18006-18023. [PMID: 28924046 DOI: 10.1074/jbc.m117.813477] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Indexed: 12/13/2022] Open
Abstract
To understand the mechanism for assembly of Lys48-linked polyubiquitin degradation signals, we previously demonstrated that the E6AP/UBE3A ligase harbors two functionally distinct E2∼ubiquitin-binding sites: a high-affinity Site 1 required for E6AP Cys820∼ubiquitin thioester formation and a canonical Site 2 responsible for subsequent chain elongation. Ordered binding to Sites 1 and 2 is here revealed by observation of UbcH7∼ubiquitin-dependent substrate inhibition of chain formation at micromolar concentrations. To understand substrate inhibition, we exploited the PatchDock algorithm to model in silico UbcH7∼ubiquitin bound to Site 1, validated by chain assembly kinetics of selected point mutants. The predicted structure buries an extensive solvent-excluded surface bringing the UbcH7∼ubiquitin thioester bond within 6 Å of the Cys820 nucleophile. Modeling onto the active E6AP trimer suggests that substrate inhibition arises from steric hindrance between Sites 1 and 2 of adjacent subunits. Confirmation that Sites 1 and 2 function in trans was demonstrated by examining the effect of E6APC820A on wild-type activity and single-turnover pulse-chase kinetics. A cyclic proximal indexation model proposes that Sites 1 and 2 function in tandem to assemble thioester-linked polyubiquitin chains from the proximal end attached to Cys820 before stochastic en bloc transfer to the target protein. Non-reducing SDS-PAGE confirms assembly of the predicted Cys820-linked 125I-polyubiquitin thioester intermediate. Other studies suggest that Glu550 serves as a general base to generate the Cys820 thiolate within the low dielectric binding interface and Arg506 functions to orient Glu550 and to stabilize the incipient anionic transition state during thioester exchange.
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Affiliation(s)
| | - Elizabeth D Kim
- From the Department of Biochemistry and Molecular Biology and
| | - Christopher M Summa
- the Department of Computer Science, University of New Orleans, New Orleans, Louisiana 70148
| | | | - Arthur L Haas
- From the Department of Biochemistry and Molecular Biology and .,the Stanley S. Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112 and
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19
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Ibragimova MK, Tsyganov MM, Karabut IV, Churuksaeva ON, Shpileva ON, Bychkov VA, Kolomiets LA, Litviakov NV. Integrative and episomal forms of genotype 16 of human papillomavirus in patients with cervical intraepithelial neoplasia and cervical cancer. Vopr Virusol 2016; 61:270-274. [PMID: 36494986 DOI: 10.18821/0507-4088-2016-61-6-270-274] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Indexed: 12/13/2022]
Abstract
The study involved 500 patients with LSIL (low grade squamous intraepithelial lesion), HSIL (high grade squamous intraepithelial lesion), stage I-IV cervical cancer, infected with human papillomavirus (HPV), as well as 235 women without pathological changes in cervical mucosa. The comprehensive survey included colposcopy, cytological and histological analysis, detection and genotyping of high-risk human papillomavirus. Viral load and physical status of HPV16 DNA was evaluated in cases of mono-infection (n = 148). The prevalence of virus-positive cases among the patients with LSIL/NSIL, cervical cancer patients and healthy women was 69.2%, 76.7% and 51.9%, respectively. An association between the severity of disease and high viral load was revealed. The frequency of integrated DNA was strongly increased in patients with a high viral load. The frequency of episomal forms was either reduced or not detecteable in patients with high viral load as compared to patients with low viral load. It is reasonable to suggest that a high HPV16 viral load may cause an increase in the frequency of integration of virus DNA into the cellular/host genome. This suggests that a high HPV16 viral load may be considered as a risk factor for prognosis of cervical intraepithelial neoplasia and cervical cancer.
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Affiliation(s)
- M K Ibragimova
- Tomsk Cancer Research Institute.,National Research Tomsk State University
| | - M M Tsyganov
- Tomsk Cancer Research Institute.,National Research Tomsk State University
| | - I V Karabut
- Tomsk Cancer Research Institute.,Siberian State Medical University
| | | | | | | | - L A Kolomiets
- Tomsk Cancer Research Institute.,Siberian State Medical University
| | - N V Litviakov
- Tomsk Cancer Research Institute.,National Research Tomsk State University
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20
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Illiano E, Demurtas OC, Massa S, Di Bonito P, Consalvi V, Chiaraluce R, Zanotto C, De Giuli Morghen C, Radaelli A, Venuti A, Franconi R. Production of functional, stable, unmutated recombinant human papillomavirus E6 oncoprotein: implications for HPV-tumor diagnosis and therapy. J Transl Med 2016; 14:224. [PMID: 27465494 PMCID: PMC4963926 DOI: 10.1186/s12967-016-0978-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 07/13/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND High-risk human papillomaviruses (HR-HPVs) types 16 and 18 are the main etiological agents of cervical cancer, with more than 550,000 new cases each year worldwide. HPVs are also associated with other ano-genital and head-and-neck tumors. The HR-HPV E6 and E7 oncoproteins are responsible for onset and maintenance of the cell transformation state, and they represent appropriate targets for development of diagnostic and therapeutic tools. METHODS The unmutated E6 gene from HPV16 and HPV18 and from low-risk HPV11 was cloned in a prokaryotic expression vector for expression of the Histidine-tagged E6 protein (His6-E6), according to a novel procedure. The structural properties were determined using circular dichroism and fluorescence spectroscopy. His6-E6 oncoprotein immunogenicity was assessed in a mouse model, and its functionality was determined using in vitro GST pull-down and protein degradation assays. RESULTS The His6-tagged E6 proteins from HPV16, HPV18, and HPV11 E6 genes, without any further modification in the amino-acid sequence, were produced in bacteria as soluble and stable molecules. Structural analyses of HPV16 His6-E6 suggests that it maintains correct folding and conformational properties. C57BL/6 mice immunized with HPV16 His6-E6 developed significant humoral immune responses. The E6 proteins from HPV16, HPV18, and HPV11 were purified according to a new procedure, and investigated for protein-protein interactions. HR-HPV His6-E6 bound p53, the PDZ1 motif from MAGI-1 proteins, the human discs large tumor suppressor, and the human ubiquitin ligase E6-associated protein, thus suggesting that it is biologically active. The purified HR-HPV E6 proteins also targeted the MAGI-3 and p53 proteins for degradation. CONCLUSIONS This new procedure generates a stable, unmutated HPV16 E6 protein, which maintains the E6 properties in in vitro binding assays. This will be useful for basic studies, and for development of diagnostic kits and immunotherapies in preclinical mouse models of HPV-related tumorigenesis.
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Affiliation(s)
- Elena Illiano
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Via Balzaretti 9, 20133, Milan, Italy.,Laboratory of Biomedical Technologies (SSPT-TECS-TEB), Department for Sustainability, Division of Health Protection Technologies, Italian National Agency for New Technologies, Energy and the Environment (ENEA), 'Casaccia' Research Centre, Via Anguillarese 301, 00123, Rome, Italy
| | - Olivia Costantina Demurtas
- Laboratory of Biotechnology (SSPT-BIOAG-BIOTEC), Department for Sustainability, Division Biotechnology and Agroindustry, Italian National Agency for New Technologies, Energy and the Environment (ENEA), 'Casaccia' Research Centre, Via Anguillarese 301, 00123 Rome, Italy
| | - Silvia Massa
- Laboratory of Biotechnology (SSPT-BIOAG-BIOTEC), Department for Sustainability, Division Biotechnology and Agroindustry, Italian National Agency for New Technologies, Energy and the Environment (ENEA), 'Casaccia' Research Centre, Via Anguillarese 301, 00123 Rome, Italy
| | - Paola Di Bonito
- Department of Infectious Diseases, Istituto Superiore Sanità, Viale Regina Elena 299, 00185, Rome, Italy
| | - Valerio Consalvi
- 'A. Rossi Fanelli' Department of Biochemical Sciences, University of Rome 'La Sapienza', P.le Aldo Moro 5, 00185, Rome, Italy
| | - Roberta Chiaraluce
- 'A. Rossi Fanelli' Department of Biochemical Sciences, University of Rome 'La Sapienza', P.le Aldo Moro 5, 00185, Rome, Italy
| | - Carlo Zanotto
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129, Milan, Italy
| | - Carlo De Giuli Morghen
- Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129, Milan, Italy.,Catholic University 'Our Lady of Good Counsel', Tirana, Albania
| | - Antonia Radaelli
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Via Balzaretti 9, 20133, Milan, Italy.,Cellular and Molecular Pharmacology Section, CNR Institute of Neurosciences, University of Milan, 20129, Milan, Italy
| | - Aldo Venuti
- HPV-UNIT, Ridait Department, Regina Elena National Cancer Institute, Via E. Chianesi 53, 00144, Rome, Italy.
| | - Rosella Franconi
- Laboratory of Biomedical Technologies (SSPT-TECS-TEB), Department for Sustainability, Division of Health Protection Technologies, Italian National Agency for New Technologies, Energy and the Environment (ENEA), 'Casaccia' Research Centre, Via Anguillarese 301, 00123, Rome, Italy.
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21
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TERT promoter hot spot mutations are frequent in Indian cervical and oral squamous cell carcinomas. Tumour Biol 2015; 37:7907-13. [DOI: 10.1007/s13277-015-4694-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 12/16/2015] [Indexed: 02/06/2023] Open
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22
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Whang SN, Filippova M, Duerksen-Hughes P. Recent Progress in Therapeutic Treatments and Screening Strategies for the Prevention and Treatment of HPV-Associated Head and Neck Cancer. Viruses 2015; 7:5040-65. [PMID: 26393639 PMCID: PMC4584304 DOI: 10.3390/v7092860] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 08/17/2015] [Accepted: 08/27/2015] [Indexed: 12/11/2022] Open
Abstract
The rise in human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC) has elicited significant interest in the role of high-risk HPV in tumorigenesis. Because patients with HPV-positive HNSCC have better prognoses than do their HPV-negative counterparts, current therapeutic strategies for HPV+ HNSCC are increasingly considered to be overly aggressive, highlighting a need for customized treatment guidelines for this cohort. Additional issues include the unmet need for a reliable screening strategy for HNSCC, as well as the ongoing assessment of the efficacy of prophylactic vaccines for the prevention of HPV infections in the head and neck regions. This review also outlines a number of emerging prospects for therapeutic vaccines, as well as for targeted, molecular-based therapies for HPV-associated head and neck cancers. Overall, the future for developing novel and effective therapeutic agents for HPV-associated head and neck tumors is promising; continued progress is critical in order to meet the challenges posed by the growing epidemic.
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Affiliation(s)
- Sonia N Whang
- Department of Basic Science, Loma Linda University, Loma Linda, CA 92354, USA.
| | - Maria Filippova
- Department of Basic Science, Loma Linda University, Loma Linda, CA 92354, USA.
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23
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Human Papillomavirus: Current and Future RNAi Therapeutic Strategies for Cervical Cancer. J Clin Med 2015; 4:1126-55. [PMID: 26239469 PMCID: PMC4470221 DOI: 10.3390/jcm4051126] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 05/08/2015] [Indexed: 12/16/2022] Open
Abstract
Human papillomaviruses (HPVs) are small DNA viruses; some oncogenic ones can cause different types of cancer, in particular cervical cancer. HPV-associated carcinogenesis provides a classical model system for RNA interference (RNAi) based cancer therapies, because the viral oncogenes E6 and E7 that cause cervical cancer are expressed only in cancerous cells. Previous studies on the development of therapeutic RNAi facilitated the advancement of therapeutic siRNAs and demonstrated its versatility by siRNA-mediated depletion of single or multiple cellular/viral targets. Sequence-specific gene silencing using RNAi shows promise as a novel therapeutic approach for the treatment of a variety of diseases that currently lack effective treatments. However, siRNA-based targeting requires further validation of its efficacy in vitro and in vivo, for its potential off-target effects, and of the design of conventional therapies to be used in combination with siRNAs and their drug delivery vehicles. In this review we discuss what is currently known about HPV-associated carcinogenesis and the potential for combining siRNA with other treatment strategies for the development of future therapies. Finally, we present our assessment of the most promising path to the development of RNAi therapeutic strategies for clinical settings.
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24
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Chopjitt P, Pientong C, Bumrungthai S, Kongyingyoes B, Ekalaksananan T. Activities of E6 Protein of Human Papillomavirus 16 Asian Variant on miR-21 Up-regulation and Expression of Human Immune Response Genes. Asian Pac J Cancer Prev 2015; 16:3961-8. [DOI: 10.7314/apjcp.2015.16.9.3961] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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25
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Popoca-Cuaya M, Diaz-Chavez J, Hernandez-Monge J, Alvarez-Rios E, Lambert PF, Gariglio P. The HPV16 E6 oncoprotein and UVB irradiation inhibit the tumor suppressor TGFβ pathway in the epidermis of the K14E6 transgenic mouse. Exp Dermatol 2015; 24:430-5. [DOI: 10.1111/exd.12689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2015] [Indexed: 12/18/2022]
Affiliation(s)
- Marco Popoca-Cuaya
- Department of Genetics and Molecular Biology; Centro de Investigación y de Estudios Avanzados (CINVESTAV); Mexico City Mexico
| | - Jose Diaz-Chavez
- Unit of Biomedical Research in Cancer; UNAM/Instituto Nacional de Cancerología (INCan); Mexico City Mexico
| | - Jesus Hernandez-Monge
- Department of Genetics and Molecular Biology; Centro de Investigación y de Estudios Avanzados (CINVESTAV); Mexico City Mexico
| | - Elizabeth Alvarez-Rios
- Department of Genetics and Molecular Biology; Centro de Investigación y de Estudios Avanzados (CINVESTAV); Mexico City Mexico
| | - Paul F. Lambert
- McArdle Laboratory for Cancer Research; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Patricio Gariglio
- Department of Genetics and Molecular Biology; Centro de Investigación y de Estudios Avanzados (CINVESTAV); Mexico City Mexico
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26
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Turunen A, Syrjänen S. Extracellular calcium regulates keratinocyte proliferation and HPV 16 E6 RNA expression in vitro. APMIS 2014; 122:781-9. [PMID: 25295350 PMCID: PMC4282442 DOI: 10.1111/apm.12227] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Human papillomaviruses (HPV) are known to immortalize oral keratinocytes in vitro, but the underlying mechanisms causing the following resistance to differentiation remain unclear. We investigated the effect of extracellular calcium on the proliferation of HPV16-positive keratinocytes and on the mRNA expression of the viral E6-oncogene. HPV16-positive hypopharyngeal carcinoma cells (UD-SCC-2), spontaneously immortalized- (HMK) and HPV16 E6/E7-immortalized human gingival keratinocytes (IHGK) were grown for 3, 6 and 9 days in Keratinocyte Serum-free Medium with calcium concentrations ranging from 0 mM to 6 mM. Calcium concentrations up to 0.09 mM increased cellular proliferation, which decreased at higher concentrations. A shift of calcium concentration from 0 to 4 mM increased E6 expression in UD-SCC-2 cells 2.4-fold by day 9. Simultaneously, E2 expression increased. The most significant upregulation of E6 and E2 expressions was observed at day 9, grown in high-calcium media and the increase in E6 expression coincided with an increase in involucrin expression, likely indicating cell differentiation. Despite this, HPV-positive cells continued to proliferate even at high-calcium media in contrast to HPV-negative cells. Overexpression of E6 mRNA may be an important feature of HPV16-positive cells to resist the natural calcium gradient in differentiating keratinocytes allowing cell proliferation.
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Affiliation(s)
- Aaro Turunen
- Department of Oral Pathology, Institute of Dentistry, University of TurkuTurku, Finland
- Aaro Turunen, Department of Oral Pathology, Institute of Dentistry, Lemminkäisenkatu 2, 20520 Turku, Finland. e-mail:
| | - Stina Syrjänen
- Department of Oral Pathology, Institute of Dentistry, University of TurkuTurku, Finland
- Department of Pathology, Turku University HospitalTurku, Finland
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Cotugno R, Basile A, Romano E, Gallotta D, Belisario MA. BAG3 down-modulation sensitizes HPV18(+) HeLa cells to PEITC-induced apoptosis and restores p53. Cancer Lett 2014; 354:263-71. [PMID: 25175321 PMCID: PMC7116956 DOI: 10.1016/j.canlet.2014.08.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/28/2014] [Accepted: 08/18/2014] [Indexed: 12/19/2022]
Abstract
BAG3 down-modulation by siRNA technology restored p53. Reduced BAG3 expression sensitized HeLa but not C33A (HPV-negative) cells to PEITC. Reduced BAG3 expression was associated with a decrease of E6 viral protein levels.
BAG3 is a multi-functional component of tumor cell pro-survival machinery, and its biological functions have been largely associated to proteasome system. Here, we show that BAG3 down-modulation resulted in reduced cell viability and enhanced PEITC-induced apoptosis largely more extensively in HeLa (HPV18+) rather than in C33A (HPV−) cervical carcinoma cell lines. Moreover, we demonstrate that BAG3 suppression led to a decrease of viral E6 oncoprotein and a concomitant recovery of p53 tumor suppressor, the best recognized target of E6 for proteasome degradation. E6 and p53 expression were modulated at protein level, since their respective mRNAs were unaffected. Taken together our findings reveal a novel role for BAG3 as host protein contributing to HPV18 E6-activated pro-survival strategies, and suggest a possible relevance of its expression levels in drug/radiotherapy-resistance of HPV18-bearing cervical carcinomas.
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Affiliation(s)
- Roberta Cotugno
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II n.132, Fisciano, 84084, Salerno, Italy
| | - Anna Basile
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II n.132, Fisciano, 84084, Salerno, Italy
| | - Elena Romano
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II n.132, Fisciano, 84084, Salerno, Italy
| | - Dario Gallotta
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II n.132, Fisciano, 84084, Salerno, Italy
| | - Maria Antonietta Belisario
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II n.132, Fisciano, 84084, Salerno, Italy.
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Habbous S, Pang V, Xu W, Amir E, Liu G. Human papillomavirus and host genetic polymorphisms in carcinogenesis: a systematic review and meta-analysis. J Clin Virol 2014; 61:220-9. [PMID: 25174543 DOI: 10.1016/j.jcv.2014.07.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 07/26/2014] [Accepted: 07/30/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND As the role of human papillomavirus (HPV) in carcinogenesis continues to rise, the role of genetic factors that modify this risk have become increasingly important. In this study, we reviewed the literature for associations between polymorphisms and HPV in carcinogenesis. OBJECTIVE To identify any associations of genetic polymorphisms with oncogenic HPV in carcinogenesis and to evaluate the methodology used. STUDY DESIGN Systematic literature review of HPV, genetic polymorphisms, and cancer risk. Odds ratios (OR), interaction terms, and p-values were tabulated. Meta-analyses and measures of heterogeneity were estimated using RevMan 5.1. RESULTS The cervix was the most frequently studied cancer site followed by the head and neck. Overall risk of cancer (cancer vs. control) was the most common comparison, whereas reports of initiation (pre-cancer vs. control) and progression (cancer vs. pre-cancer) were rare. Case-series and joint-effect of HPV and genotype on risk was evaluated frequently, but the independent effect of either risk factor alone was rarely provided. P53-Arg72Pro was the most commonly studied polymorphism studied. No consistent interaction was detected by meta-analysis in the HPV(+) [OR 0.98 (0.55-1.76)] or the HPV(-) [OR 1.10 (0.76-1.60)] subsets in head and neck cancer risk. Polymorphisms in genes known to encode proteins that physically interact with HPV were infrequently studied. CONCLUSION No consistent polymorphism-HPV interactions were observed. Study design, choice of candidate polymorphisms/genes, and a focus on overall risk rather than any specific portions of the carcinogenic pathway may have contributed to lack of significant findings.
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Affiliation(s)
- Steven Habbous
- Ontario Cancer Institute, Princess Margaret Cancer Centre, Toronto, Ontario, Canada M5G 2M9
| | - Vincent Pang
- Ontario Cancer Institute, Princess Margaret Cancer Centre, Toronto, Ontario, Canada M5G 2M9
| | - Wei Xu
- Ontario Cancer Institute, Princess Margaret Cancer Centre, Toronto, Ontario, Canada M5G 2M9; Department of Biostatistics, Princess Margaret Cancer Centre, Toronto, Ontario, Canada M5G 2M9
| | - Eitan Amir
- Ontario Cancer Institute, Princess Margaret Cancer Centre, Toronto, Ontario, Canada M5G 2M9; Division of Medical Oncology and Hematology, Toronto, Ontario, Canada M5G 2M9
| | - Geoffrey Liu
- Ontario Cancer Institute, Princess Margaret Cancer Centre, Toronto, Ontario, Canada M5G 2M9; Medicine and Epidemiology, Dalla Lana School of Public Health, University of Toronto, Canada M5G 2M9.
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Omran OM, AlSheeha M. Human Papilloma Virus Early Proteins E6 (HPV16/18-E6) and the Cell Cycle Marker P16 (INK4a) are Useful Prognostic Markers in Uterine Cervical Carcinomas in Qassim Region- Saudi Arabia. Pathol Oncol Res 2014; 21:157-66. [DOI: 10.1007/s12253-014-9801-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 05/16/2014] [Indexed: 10/25/2022]
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Abstract
UNLABELLED High-risk types of human papillomavirus (HPV) are the causative agents of virtually all cases of cervical cancer and a significant proportion of other anogenital cancers, as well as both oral and pharyngeal cancers. The high-risk types encode two viral oncogenes, E6 and E7, which work together to initiate cell transformation. Multiple steps involving the activities and interactions of both viral and cellular proteins are involved in the progression from HPV infection to cell transformation to cancer. The E6 oncoprotein is expressed as several isoforms: a full-length variant referred to as E6 and a few shorter isoforms collectively referred to as E6*. In this study, we found that expression of E6* increased the level of reactive oxygen species (ROS) in both HPV-positive and HPV-negative cells. This increased oxidative stress led to higher levels of DNA damage, as assessed by the comet assay, quantification of 8-oxoguanine, and poly(ADP-ribose) polymerase 1. The observed increase in ROS may be due to a decrease in cellular antioxidant activity, as we found that E6* expression also led to decreased expression of superoxide dismutase isoform 2 and glutathione peroxidase. These studies indicate that E6* may play an important role in virus-induced mutagenesis by increasing oxidative stress and DNA damage. IMPORTANCE Our findings demonstrate for the first time that an HPV gene product, E6*, can increase ROS levels in host cells. This ability may play a significant role both in the viral life cycle and in cancer development, because an increase in oxidative DNA damage may both facilitate HPV genome amplification and increase the probability of HPV16 DNA integration. Integration, in turn, is thought to be an important step in HPV-mediated carcinogenesis.
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Tagle DKJ, Sotelo DH, Illades-Aguiar B, Leyva-Vazquez MA, Alfaro EF, Coronel YC, Hernández ODM, Romero LDCA. Expression of E6, p53 and p21 proteins and physical state of HPV16 in cervical cytologies with and without low grade lesions. Int J Clin Exp Med 2014; 7:186-193. [PMID: 24482706 PMCID: PMC3902258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 11/21/2013] [Indexed: 06/03/2023]
Abstract
The aim of this study was to determine the correlation between expression of HPV16 E6, p53 and p21 proteins and the physical state of HPV16 in cervical cytologies without squamous intraepithelial lesions (Non-SIL) and with low grade squamous intraepithelial lesions (LSIL), both with HPV16 infection. 101 liquid-based cytological samples were analyzed. 50 samples were without squamous intraepithelial lesions (Non-IL) and 51 samples of low grade squamous intraepithelial lesions (LSIL), both with HPV16 infection. HPV16 infection was determined by PCR-RFLP, and the physical state of HPV16 by in situ hybridization with tyramide-amplification. The expression of E6, p53 and p21 proteins was evaluated by immunocytochemistry. The expression of HPV16 E6 protein was significantly higher in LSIL that in Non-SIL samples (p=0.006). We found a significant correlation between E6 expression and the physical state of HPV16 in Non-SIL (p=0.049). Our results suggest that high expression of E6 in LSIL is an early event of cervical carcinogenesis and perhaps can be used as an early marker.
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Affiliation(s)
- Diana K Jiménez Tagle
- Laboratorio de Investigación en Citopatología e Histoquímica, Unidad Académica de Ciencias Químico Biológicas Universidad Autónoma de Guerrero Avenida Lázaro Cárdenas, Ciudad UniversitariaChilpancingo, Guerrero, México. C.P. 39090, México
| | - Daniel Hernández Sotelo
- Laboratorio de Biomedicina Molecular, Unidad Académica de Ciencias Químico Biológicas Universidad Autónoma de Guerrero Avenida Lázaro Cárdenas, Ciudad UniversitariaChilpancingo, Guerrero, México. C.P. 39090, México
| | - Berenice Illades-Aguiar
- Laboratorio de Biomedicina Molecular, Unidad Académica de Ciencias Químico Biológicas Universidad Autónoma de Guerrero Avenida Lázaro Cárdenas, Ciudad UniversitariaChilpancingo, Guerrero, México. C.P. 39090, México
| | - Marco A Leyva-Vazquez
- Laboratorio de Biomedicina Molecular, Unidad Académica de Ciencias Químico Biológicas Universidad Autónoma de Guerrero Avenida Lázaro Cárdenas, Ciudad UniversitariaChilpancingo, Guerrero, México. C.P. 39090, México
| | - Eugenia Flores Alfaro
- Laboratorio de Epidemiologia Molecular, Unidad Académica de Ciencias Químico Biológicas Universidad Autónoma de Guerrero Avenida Lázaro Cárdenas, Ciudad UniversitariaChilpancingo, Guerrero, México. C.P. 39090, México
| | - Yaneth Castro Coronel
- Laboratorio de Investigación en Citopatología e Histoquímica, Unidad Académica de Ciencias Químico Biológicas Universidad Autónoma de Guerrero Avenida Lázaro Cárdenas, Ciudad UniversitariaChilpancingo, Guerrero, México. C.P. 39090, México
| | - Oscar del Moral Hernández
- Laboratorio de Biomedicina Molecular, Unidad Académica de Ciencias Químico Biológicas Universidad Autónoma de Guerrero Avenida Lázaro Cárdenas, Ciudad UniversitariaChilpancingo, Guerrero, México. C.P. 39090, México
| | - Luz del Carmen Alarcón Romero
- Laboratorio de Investigación en Citopatología e Histoquímica, Unidad Académica de Ciencias Químico Biológicas Universidad Autónoma de Guerrero Avenida Lázaro Cárdenas, Ciudad UniversitariaChilpancingo, Guerrero, México. C.P. 39090, México
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Cherry JJ, Rietz A, Malinkevich A, Liu Y, Xie M, Bartolowits M, Davisson VJ, Baleja JD, Androphy EJ. Structure based identification and characterization of flavonoids that disrupt human papillomavirus-16 E6 function. PLoS One 2013; 8:e84506. [PMID: 24376816 PMCID: PMC3871595 DOI: 10.1371/journal.pone.0084506] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 11/20/2013] [Indexed: 02/07/2023] Open
Abstract
Expression and function of the human papillomavirus (HPV) early protein 6 (E6) is necessary for viral replication and oncogenesis in cervical cancers. HPV E6 targets the tumor suppressor protein p53 for degradation. To achieve this, "high-risk" HPV E6 proteins bind to and modify the target specificity of the ubiquitin ligase E6AP (E6 associated protein). This E6-dependent loss of p53 enables the virus to bypass host cell defenses and facilitates virally induced activation of the cell cycle progression during viral replication. Disruption of the interaction between E6 and E6AP and stabilization of p53 should decrease viability and proliferation of HPV positive cells. A new in vitro high-throughput binding assay was developed to assay binding between HPV-16 E6 and E6AP and to identify compounds that inhibit this interaction. The compound luteolin emerged from the screen and a library of novel flavones based on its structure was synthesized and characterized using this in vitro binding assay. The compounds identified in this study disrupt the E6/E6AP interaction, increase the levels of p53 and p21(Cip1/Waf1), and decrease proliferation of HPV positive cell lines. The new class of flavonoid E6 inhibitors displays a high degree of specificity for HPV positive cells. Docking analyses suggest that these compounds bind in a hydrophobic pocket at the interface between E6 and E6AP and mimic the leucines in the conserved α-helical motif of E6AP. The activity and specificity of these compounds represent a promising new lead for development as an antiviral therapy in the treatment of HPV infection and cervical cancer.
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Affiliation(s)
- Jonathan J. Cherry
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Anne Rietz
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Anna Malinkevich
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Yuqi Liu
- Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Meng Xie
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Matthew Bartolowits
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, West Lafayette, Indiana, United States of America
| | - V. Jo Davisson
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University College of Pharmacy, West Lafayette, Indiana, United States of America
| | - James D. Baleja
- Department of Biochemistry, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Elliot J. Androphy
- Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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Campos-Ferreira DS, Nascimento GA, Souza EV, Souto-Maior MA, Arruda MS, Zanforlin DM, Ekert MH, Bruneska D, Lima-Filho JL. Electrochemical DNA biosensor for human papillomavirus 16 detection in real samples. Anal Chim Acta 2013; 804:258-63. [DOI: 10.1016/j.aca.2013.10.038] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 10/08/2013] [Accepted: 10/16/2013] [Indexed: 12/21/2022]
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Vande Pol SB, Klingelhutz AJ. Papillomavirus E6 oncoproteins. Virology 2013; 445:115-37. [PMID: 23711382 DOI: 10.1016/j.virol.2013.04.026] [Citation(s) in RCA: 248] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Revised: 04/22/2013] [Accepted: 04/25/2013] [Indexed: 02/07/2023]
Abstract
Papillomaviruses induce benign and malignant epithelial tumors, and the viral E6 oncoprotein is essential for full transformation. E6 contributes to transformation by associating with cellular proteins, docking on specific acidic LXXLL peptide motifs found on these proteins. This review examines insights from recent studies of human and animal E6 proteins that determine the three-dimensional structure of E6 when bound to acidic LXXLL peptides. The structure of E6 is related to recent advances in the purification and identification of E6 associated protein complexes. These E6 protein-complexes, together with other proteins that bind to E6, alter a broad array of biological outcomes including modulation of cell survival, cellular transcription, host cell differentiation, growth factor dependence, DNA damage responses, and cell cycle progression.
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Affiliation(s)
- Scott B Vande Pol
- Department of Pathology, University of Virginia, Charlottesville, VA 22901, USA.
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35
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Roncaglia MT, Fregnani JHTG, Tacla M, DE Campos SGP, Caiaffa HH, Ab'saber A, DA Motta EV, Alves VAF, Baracat EC, Longatto Filho A. Characterization of p16 and E6 HPV-related proteins in uterine cervix high-grade lesions of patients treated by conization with large loop excision. Oncol Lett 2013; 6:63-68. [PMID: 23946778 PMCID: PMC3742822 DOI: 10.3892/ol.2013.1356] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/25/2013] [Indexed: 11/09/2022] Open
Abstract
Cervical cancer and its precursor lesions represent a significant public health problem for developing and less-developed countries. Cervical carcinogenesis is strongly correlated with persistent high-risk human papillomavirus (HPV) infection, which is mostly associated with expression of the p16 and E6 HPV-related proteins. The aim of this present study was to determine the expression of the p16 and E6 proteins in females with high-grade lesions treated with conization, and to discuss the role of these proteins as prognostic markers following treatment. In total, 114 females were treated for high-grade cervical intraepithelial neoplasia (CIN, grades 2/3) by conization with large loop excision of the transformation zone (LLETZ). Following surgery, the patients returned within 30–45 days for post-operative evaluation. A follow-up was conducted every 6 months for 2 years. At each follow-up appointment, a Pap smear, colposcopy and HPV DNA test were performed. E6 and p16 immunohistochemical tests were conducted on the surgical specimens. The positive expression of p16 was correlated with the presence of lesions with increased severity in the surgical specimens (P= 0.0001). The expression of E6 did not demonstrate the same correlation (P=0.131). The HPV DNA hybrid, collected in the first post-operative consultation as a predictor of the cytological abnormalities identified at the 24-month follow-up assessment, presented a sensitivity of 55.6%, a specificity of 84.8%, a positive predictive value of 33.3% and a negative predictive value of 93.3%. The role of p16INK4A as a marker of CIN was also demonstrated; the expression of p16 and E6, however, did not appear to be of any prognostic value in predicting the clearance of high-risk HPV following conization. A negative hybrid capture test was correlated with a disease-free outcome.
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Affiliation(s)
- Maria Teresa Roncaglia
- Department of Gynecology, Faculty of Medicine, São Paulo University, Cerqueira César, São Paulo, Brazil
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Mischo A, Ohlenschläger O, Hortschansky P, Ramachandran R, Görlach M. Structural insights into a wildtype domain of the oncoprotein E6 and its interaction with a PDZ domain. PLoS One 2013; 8:e62584. [PMID: 23638119 PMCID: PMC3640046 DOI: 10.1371/journal.pone.0062584] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 03/22/2013] [Indexed: 12/17/2022] Open
Abstract
The high-risk human papilloma virus (HPV) oncoproteins E6 and E7 interact with key cellular regulators and are etiological agents for tumorigenesis and tumor maintenance in cervical cancer and other malignant conditions. E6 induces degradation of the tumor suppressor p53, activates telomerase and deregulates cell polarity. Analysis of E6 derived from a number of high risk HPV finally yielded the first structure of a wild-type HPV E6 domain (PDB 2M3L) representing the second zinc-binding domain of HPV 51 E6 (termed 51Z2) determined by NMR spectroscopy. The 51Z2 structure provides clues about HPV-type specific structural differences between E6 proteins. The observed temperature sensitivity of the well-folded wild-type E6 domain implies a significant malleability of the oncoprotein in vivo. Hence, the structural differences between individual E6 and their malleability appear, together with HPV type-specific surface exposed side-chains, to provide the structural basis for the different interaction networks reported for individual E6 proteins. Furthermore, the interaction of 51Z2 with a PDZ domain of hDlg was analyzed. Human Dlg constitutes a prototypic representative of the large family of PDZ proteins regulating cell polarity, which are common targets of high-risk HPV E6. Nine C-terminal residues of 51Z2 interact with the second PDZ domain of hDlg2. Surface plasmon resonance in conjunction with the NMR spectroscopy derived complex structure (PDB 2M3M) indicate that E6 residues N-terminal to the canonical PDZ-BM of E6 significantly contribute to this interaction and increase affinity. The structure of the complex reveals how residues outside of the classical PDZ-BM enhance the affinity of E6 towards PDZ domains. Such mechanism facilitates successful competition of E6 with cellular PDZ-binding proteins and may apply to PDZ-binding proteins of other viruses as well.
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Affiliation(s)
- André Mischo
- Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research - Fritz Lipmann Institute, Jena, Germany
| | - Oliver Ohlenschläger
- Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research - Fritz Lipmann Institute, Jena, Germany
| | - Peter Hortschansky
- Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany
| | - Ramadurai Ramachandran
- Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research - Fritz Lipmann Institute, Jena, Germany
| | - Matthias Görlach
- Biomolecular NMR Spectroscopy, Leibniz Institute for Age Research - Fritz Lipmann Institute, Jena, Germany
- * E-mail:
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Zhou Q, Zhu K, Cheng H. Toll-like receptors in human papillomavirus infection. Arch Immunol Ther Exp (Warsz) 2013; 61:203-15. [PMID: 23435874 DOI: 10.1007/s00005-013-0220-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 02/13/2013] [Indexed: 01/02/2023]
Abstract
Infection with human papillomaviruses (HPVs) often causes cutaneous benign lesions, cervical cancer, and a number of other tumors. The mechanisms of host immune system to prevent and control HPV infection still remain poorly understood. Toll-like receptors (TLRs) are specific pattern recognition molecules that bind to microbial components to trigger innate immunity and direct adaptive immunity in the face of immunological danger. TLRs have been established to play an essential role in sensing and initiating antiviral immune responses. Recent accumulating evidence demonstrated that HPVs modulate TLR expression and interfere with TLR signaling pathways, leading to persistent viral infection and carcinogenesis. This review summarizes current knowledge on the roles of TLR during HPV infection, focusing on TLR recognition, modulation of TLR expression and signaling, regulatory receptors involved in TLR signaling, and cross-talk of TLRs with antimicrobial peptides. Immunotherapeutic strategies based on TLR agonists have emerged to be one of the novel promising avenues in treatment of HPV-associated diseases in the future.
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Affiliation(s)
- Qiang Zhou
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, 3 Qingchun Road East, Hangzhou 310016, People's Republic of China
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Zanier K, Charbonnier S, Sidi AOMO, McEwen AG, Ferrario MG, Poussin-Courmontagne P, Cura V, Brimer N, Babah KO, Ansari T, Muller I, Stote RH, Cavarelli J, Vande Pol S, Travé G. Structural basis for hijacking of cellular LxxLL motifs by papillomavirus E6 oncoproteins. Science 2013; 339:694-8. [PMID: 23393263 DOI: 10.1126/science.1229934] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
E6 viral oncoproteins are key players in epithelial tumors induced by papillomaviruses in vertebrates, including cervical cancer in humans. E6 proteins target many host proteins by specifically interacting with acidic LxxLL motifs. We solved the crystal structures of bovine (BPV1) and human (HPV16) papillomavirus E6 proteins bound to LxxLL peptides from the focal adhesion protein paxillin and the ubiquitin ligase E6AP, respectively. In both E6 proteins, two zinc domains and a linker helix form a basic-hydrophobic pocket, which captures helical LxxLL motifs in a way compatible with other interaction modes. Mutational inactivation of the LxxLL binding pocket disrupts the oncogenic activities of both E6 proteins. This work reveals the structural basis of both the multifunctionality and the oncogenicity of E6 proteins.
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Affiliation(s)
- Katia Zanier
- Biotechnologie et Signalisation Cellulaire UMR 7242, Ecole Supérieure de Biotechnologie de Strasbourg, Boulevard Sébastien Brant, BP 10413, F-67412 Illkirch, France
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D'Costa ZJ, Jolly C, Androphy EJ, Mercer A, Matthews CM, Hibma MH. Transcriptional repression of E-cadherin by human papillomavirus type 16 E6. PLoS One 2012; 7:e48954. [PMID: 23189137 PMCID: PMC3506579 DOI: 10.1371/journal.pone.0048954] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Accepted: 10/03/2012] [Indexed: 02/01/2023] Open
Abstract
There is increasing evidence supporting DNA virus regulation of the cell adhesion and tumour suppressor protein, E-cadherin. We previously reported that loss of E-cadherin in human papillomavirus (HPV) type 16-infected epidermis is contributed to by the major viral proto-oncogene E6 and is associated with reduced Langerhans cells density, potentially regulating the immune response. The focus of this study is determining how the HPV16 E6 protein mediates E-cadherin repression. We found that the E-cadherin promoter is repressed in cells expressing E6, resulting in fewer E-cadherin transcripts. On exploring the mechanism for this, repression by increased histone deacetylase activity or by increased binding of trans-repressors to the E-cadherin promoter Epal element was discounted. In contrast, DNA methyltransferase (DNMT) activity was increased in E6 expressing cells. Upon inhibiting DNMT activity using 5-Aza-2'-deoxycytidine, E-cadherin transcription was restored in the presence of HPV16 E6. The E-cadherin promoter was not directly methylated, however a mutational analysis showed general promoter repression and reduced binding of the transactivators Sp1 and AML1 and the repressor Slug. Expression of E7 with E6 resulted in a further reduction in surface E-cadherin levels. This is the first report of HPV16 E6-mediated transcriptional repression of this adhesion molecule and tumour suppressor protein.
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Affiliation(s)
- Zarina J. D'Costa
- Virus Research Unit, Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Carol Jolly
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Elliot J. Androphy
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Andrew Mercer
- Virus Research Unit, Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Charles M. Matthews
- Virus Research Unit, Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Merilyn H. Hibma
- Virus Research Unit, Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
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40
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Abstract
Moonlighting--the performance of more than one function by a single protein--is becoming recognized as a common phenomenon with important implications for systems biology and human health. The different functions of a moonlighting protein may use different regions of the protein structure, or alternative structures that occur due to post-translational modifications and/or differences in binding partners. Often the different functions of moonlighting proteins are used at different times or in different places. The existence of moonlighting functions complicates efforts to understand metabolic and regulatory networks, as well as physiological and pathological processes in organisms. Because moonlighting functions can play important roles in disease processes, an improved understanding of moonlighting proteins will provide new opportunities for pharmacological manipulations that specifically target a function involved in pathology while sparing physiologically important functions.
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Affiliation(s)
- Shelley D Copley
- Department of Molecular, Cellular and Developmental Biology, Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA.
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41
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Direct human papillomavirus E6 whole-cell enzyme-linked immunosorbent assay for objective measurement of E6 oncoproteins in cytology samples. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2012; 19:1474-9. [PMID: 22815148 DOI: 10.1128/cvi.00388-12] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A novel, whole-cell enzyme-linked immunosorbent assay (ELISA) based on a non-type-specific anti-human papillomavirus (HPV) E6 antibody was tested on 182 residual cytological specimens. For samples with a designation of more severe than cervical intraepithelial neoplasia grade 3 (CIN3+), 83% tested positive for E6; in a subset with paired testing for E6 ELISA and HPV DNA, 72% tested E6 positive and 92% tested high-risk (HR)-HPV DNA positive (P = 0.2). Among the women with a less than CIN3 diagnosis, 31% and 47% tested positive for E6 and HR-HPV DNA, respectively (P = 0.0006).
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42
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Jabbar SF, Park S, Schweizer J, Berard-Bergery M, Pitot HC, Lee D, Lambert PF. Cervical cancers require the continuous expression of the human papillomavirus type 16 E7 oncoprotein even in the presence of the viral E6 oncoprotein. Cancer Res 2012; 72:4008-16. [PMID: 22700879 DOI: 10.1158/0008-5472.can-11-3085] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High-risk human papillomaviruses (HPV), such as HPV-16, are etiologic agents of a variety of anogenital and oral malignancies, including nearly all cases of cervical cancer. Cervical cancers arising in transgenic mice that express HPV-16 E7 in an inducible manner require the continuous expression of E7 for their maintenance. However, in HPV-associated cancers in vivo, E6 and E7 invariably are coexpressed. In this study, we investigated whether cervical cancers rely on the continuous expression of E7 in the context of constitutively expressed E6. We placed the inducible HPV-16 E7 transgene onto a background in which HPV-16 E6 was constitutively expressed. In transgenic mice with high-grade cervical dysplastic lesions and cervical cancer, repressing the expression of E7 led to the regression of all cancers and the vast majority of high-grade dysplastic lesions. In addition, cervical cancers were occasionally observed in transgenic mice in which E7 was repressed and then reexpressed. Our findings indicate that even in the presence of constitutively expressed E6, the continuous expression of E7 is required for the maintenance of cervical cancers and most precancerous lesions. These data have important implications for the potential clinical use of drugs designed to inhibit the expression and/or function of E7 to treat HPV-associated cancers.
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Affiliation(s)
- Sean F Jabbar
- McArdle Laboratory for Cancer Research, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706, USA
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43
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Ewald PW, Swain Ewald HA. Infection, mutation, and cancer evolution. J Mol Med (Berl) 2012; 90:535-41. [PMID: 22476248 DOI: 10.1007/s00109-012-0891-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 03/03/2012] [Accepted: 03/07/2012] [Indexed: 01/27/2023]
Abstract
An understanding of oncogenesis can be fostered by an integration of mechanistic studies with evolutionary considerations, which help explain why these mechanisms occur. This integration emphasizes infections and mutations as joint essential causes for many cancers. It suggests that infections may play a broader causal role in oncogenesis than has been generally appreciated. An evolutionary perspective also suggests that oncogenic viruses will tend to be transmitted by routes that provide infrequent opportunities for transmission, such as transmission by sexual and salivary contact. Such routes increase the intensity of natural selection for persistence within hosts, and molecular mechanisms for persistence often compromise critical barriers to oncogenesis, particularly cell cycle arrest, apoptosis, and a cap on the total number of divisions that a cell can undergo.
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Affiliation(s)
- Paul W Ewald
- Department of Biology, University of Louisville, Louisville, KY 40292, USA.
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44
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RXRα deletion and E6E7 oncogene expression are sufficient to induce cervical malignant lesions in vivo. Cancer Lett 2012; 317:226-36. [DOI: 10.1016/j.canlet.2011.11.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 11/23/2011] [Accepted: 11/23/2011] [Indexed: 01/01/2023]
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45
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Yuan CH, Filippova M, Tungteakkhun SS, Duerksen-Hughes PJ, Krstenansky JL. Small molecule inhibitors of the HPV16-E6 interaction with caspase 8. Bioorg Med Chem Lett 2012; 22:2125-9. [PMID: 22300659 DOI: 10.1016/j.bmcl.2011.12.145] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 11/30/2011] [Accepted: 12/05/2011] [Indexed: 11/25/2022]
Abstract
High-risk strains of human papillomaviruses (HPVs) cause nearly all cases of cervical cancer as well as a growing number of head and neck cancers. The oncogenicity of these viruses can be attributed to the activities of their two primary oncoproteins, E6 and E7. The E6 protein has among its functions the ability to prevent apoptosis of infected cells through its binding to FADD and caspase 8. A small molecule library was screened for candidates that could inhibit E6 binding to FADD and caspase 8. Flavonols were found to possess this activity with the rank order of myricetin>morin>quercetin>kaempferol=galangin≫(apigenin, 7-hydroxyflavonol, rhamnetin, isorhamnetin, geraldol, datiscetin, fisetin, 6-hydroxyflavonol). Counter screening, where the ability of these chosen flavonols to inhibit caspase 8 binding to itself was assessed, demonstrated that myricetin, morin and quercetin inhibited GST-E6 and His-caspase 8 binding in a specific manner. The structure-activity relationships suggested by these data are unique and do not match prior reports on flavonols in the literature for a variety of anticancer assays.
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Affiliation(s)
- Chung-Hsiang Yuan
- Department of Basic Sciences, Loma Linda University School of Medicine, 11085 Campus St., Loma Linda, CA 92354, USA
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46
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Bonilla-Delgado J, Bulut G, Liu X, Cortés-Malagón EM, Schlegel R, Flores-Maldonado C, Contreras RG, Chung SH, Lambert PF, Uren A, Gariglio P. The E6 oncoprotein from HPV16 enhances the canonical Wnt/β-catenin pathway in skin epidermis in vivo. Mol Cancer Res 2011; 10:250-8. [PMID: 22160870 DOI: 10.1158/1541-7786.mcr-11-0287] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The contribution of the Wnt signaling pathway to human papilloma virus (HPV)-induced carcinogenesis is poorly understood. In high-grade dysplastic lesions that are caused by high-risk HPVs (HR-HPV), β-catenin is often located in the cell nucleus, which suggests that Wnt pathway may be involved in the development of HPV-related carcinomas. Most of the oncogenic potential of HR-HPVs resides on the PDZ-binding domain of E6 protein. We hypothesized that the PDZ-binding domain of the HPV16-E6 oncoprotein induces the nuclear accumulation of β-catenin due to its capacity to degrade PDZ-containing cellular targets. To test this hypothesis, we evaluated the staining pattern of β-catenin in the skin epidermis of transgenic mice expressing the full-length E6 oncoprotein (K14E6 mice) and measured LacZ gene expression in K14E6 mice that were crossed with a strain expressing LacZ that was knocked into the Axin2 locus (Axin2(+/LacZ) mice). Here, we show that the E6 oncoprotein enhances the nuclear accumulation of β-catenin, the accumulation of cellular β-catenin-responsive genes, and the expression of LacZ. None of these effects were observed when a truncated E6 oncoprotein that lacks the PDZ-binding domain was expressed alone (K14E6ΔPDZ mice) or in combination with Axin2(+/LacZ). Conversely, cotransfection with either E6 or E6ΔPDZ similarly enhanced canonical Wnt signaling in short-term in vitro assays that used a luciferase Wnt/β-catenin/TCF-dependent promoter. We propose that the activation of canonical Wnt signaling could be induced by the HPV16-E6 oncoprotein; however, the participation of the E6 PDZ-binding domain seems to be important in in vivo models only.
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Affiliation(s)
- José Bonilla-Delgado
- Deptamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados (Cinvestav), México, México
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47
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Abnormal distribution of hDlg and PTEN in premalignant lesions and invasive cervical cancer. Gynecol Oncol 2011; 122:663-8. [PMID: 21664656 DOI: 10.1016/j.ygyno.2011.05.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Revised: 05/06/2011] [Accepted: 05/14/2011] [Indexed: 01/17/2023]
Abstract
OBJECTIVE The aim of the present study was to evaluate differences in expression levels and localization status of PTEN, p53 and hDlg suppressor proteins in premalignant lesions and cervical cancer, and to analyze the possible correlation between them. METHODS Expression levels (positivity/intensity) and localization (nuclear, membrane or cytoplasmic) of PTEN, hDlg and p53 were analyzed by immunohistochemistry in 43 cases with different stages of cervical intraepithelial neoplasia (CIN) and 105 invasive cervical carcinomas (ICC) (91 squamous carcinoma, 14 adenocarcinoma). Differences between proportions were evaluated. RESULTS We found a decreased expression of PTEN in ICC that correlated with a loss of hDlg from the cell membrane. In contrast, no changes were found in p53 protein levels or localization in CIN and ICC. CONCLUSIONS These results suggest that the abnormal expression and localization of PTEN during cervical carcinogenesis may be a consequence of modifications in the expression patterns of hDlg.
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48
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Zhou Q, Zhu K, Cheng H. Ubiquitination in host immune response to human papillomavirus infection. Arch Dermatol Res 2011; 303:217-30. [PMID: 21400034 DOI: 10.1007/s00403-011-1141-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2010] [Revised: 02/22/2011] [Accepted: 02/23/2011] [Indexed: 02/07/2023]
Abstract
Human papillomavirus (HPV) infection with low-risk or high-risk subtypes is very common. Infection with HPVs is often a major causative factor for the development of cutaneous benign lesions, cervical cancer, and a number of other tumors. The mechanisms of host immunity to prevent and control HPV infection still remain unclear. The importance of ubiquitination (or ubiquitylation) as an intracellular proteasomal-mediated protein degradation pathway, and as an important modulator for the regulation of many fundamental cellular processes has been valued over the last decade. Although the molecular and cellular mechanisms are not completely established, the critical role of ubiquitination in host immune response to HPV infection has become increasingly apparent. This review summarizes current knowledge on the possible role that ubiquitination plays in regulating the host immune response during HPV infection. Targeting the components of the ubiquitin system might offer potential therapeutic strategies for HPV-related diseases in the future.
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Affiliation(s)
- Qiang Zhou
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, People's Republic of China
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49
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Williams VM, Filippova M, Soto U, Duerksen-Hughes PJ. HPV-DNA integration and carcinogenesis: putative roles for inflammation and oxidative stress. Future Virol 2011; 6:45-57. [PMID: 21318095 DOI: 10.2217/fvl.10.73] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
HPV-DNA integration into cellular chromatin is usually a necessary event in the pathogenesis of HPV-related cancer; however, the mechanism of integration has not been clearly defined. Breaks must be created in both the host DNA and in the circular viral episome for integration to occur, and studies have shown that viral integration is indeed increased by the induction of DNA double strand breaks. Inflammation generates reactive oxygen species, which in turn have the potential to create such DNA strand breaks. It is plausible that these breaks enable a greater frequency of HPV-DNA integration, and in this way contribute to carcinogenesis. Consistent with this idea, co-infections with certain sexually transmitted diseases cause cervical inflammation, and have also been identified as cofactors in the progression to cervical cancer. This article examines the idea that inflammation facilitates HPV-DNA integration into cellular chromatin through the generation of reactive oxygen species, thereby contributing to carcinogenesis.
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Affiliation(s)
- Vonetta M Williams
- Department of Basic Science, Loma Linda University, Loma Linda, CA 92354, USA
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50
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Chi CN, Bach A, Engström Å, Strømgaard K, Lundström P, Ferguson N, Jemth P. Biophysical characterization of the complex between human papillomavirus E6 protein and synapse-associated protein 97. J Biol Chem 2010; 286:3597-606. [PMID: 21113079 DOI: 10.1074/jbc.m110.190264] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The E6 protein of human papillomavirus (HPV) exhibits complex interaction patterns with several host proteins, and their roles in HPV-mediated oncogenesis have proved challenging to study. Here we use several biophysical techniques to explore the binding of E6 to the three PDZ domains of the tumor suppressor protein synapse-associated protein 97 (SAP97). All of the potential binding sites in SAP97 bind E6 with micromolar affinity. The dissociation rate constants govern the different affinities of HPV16 and HPV18 E6 for SAP97. Unexpectedly, binding is not mutually exclusive, and all three PDZ domains can simultaneously bind E6. Intriguingly, this quaternary complex has the same apparent hydrodynamic volume as the unliganded PDZ region, suggesting that a conformational change occurs in the PDZ region upon binding, a conclusion supported by kinetic experiments. Using NMR, we discovered a new mode of interaction between E6 and PDZ: a subset of residues distal to the canonical binding pocket in the PDZ(2) domain exhibited noncanonical interactions with the E6 protein. This is consistent with a larger proportion of the protein surface defining binding specificity, as compared with that reported previously.
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Affiliation(s)
- Celestine N Chi
- Department of Medical Biochemistry and Microbiology, Uppsala University, SE-75123 Uppsala, Sweden
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