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Zhao D, Qian L, Zhuang D, Wang L, Cao Y, Zhou F, Zhang S, Liu Y, Liang Y, Zhang W, Kang W, Zhang M, Wang Y, Zhang F, Zhang W, Xiao J, Xu G, Lv Y, Zou X, Zhuge Y, Zhang B. Inhibition of ribosomal RNA processing 15 Homolog (RRP15), which is overexpressed in hepatocellular carcinoma, suppresses tumour growth via induction of senescence and apoptosis. Cancer Lett 2021; 519:315-327. [PMID: 34343634 DOI: 10.1016/j.canlet.2021.07.046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/25/2021] [Accepted: 07/28/2021] [Indexed: 01/10/2023]
Abstract
Recent studies suggest that RRP15 (Ribosomal RNA Processing 15 Homolog) might be a potential target for cancer therapy. However, the role of RRP15 in hepatocarcinogenesis remains poorly delineated. In this study, we aimed to evaluate the expression and biological function of RRP15 in human hepatocellular carcinoma (HCC). We show that RRP15 was up regulated in HCC cell lines and tumours. Up-regulation of RRP15 in HCC tumours was also correlated with unfavorable prognosis. We further show that the frequent up-regulation of RRP15 in HCCs is at least partly driven by recurrent gene copy gain at chromosome 1q41. Functional studies indicated that RRP15 knockdown suppresses HCC proliferation and growth both in vitro and in vivo. Mechanistically, RRP15 depletion in p53-wild-type HepG2 cells induced senescence via activation of the p53-p21 signalling pathway through enhanced interaction of RPL11 with MDM2, as well as inhibition of SIRT1-mediated p53 deacetylation. Moreover, RRP15 depletion in p53-mutant PLC5 and p53-deleted Hep3B cells induced metabolic shift from the glycolytic pentose-phosphate to mitochondrial oxidative phosphorylation via regulating a series of key genes such as HK2 and TIGAR, and thus, promoted the generation of ROS and apoptosis. Taken together, our findings provide evidence for an important role of the RRP15 gene in hepatocarcinogenesis through regulation of HCC proliferation and growth, raising the possibility that targeting RRP15 may represent a potential therapeutic strategy for HCC treatment.
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Affiliation(s)
- Dian Zhao
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Liping Qian
- Centre for Experimental Animal, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Duanming Zhuang
- Department of Gastroenterology, Gaochun People's Hospital, Nanjing, Jiangsu, China
| | - Lei Wang
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yu Cao
- Department of Gastroenterology, Changhai Hospital, The Second Military Medical University/Naval Medical University, Shanghai, China
| | - Fan Zhou
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Shu Zhang
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Ying Liu
- Department of Ultrasound Diagnostics, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Ying Liang
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Wenjie Zhang
- Department of Hepatobiliary Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Wei Kang
- Department of Anatomical and Cellular Pathology, State Key Laboratory of Translational Oncology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Ming Zhang
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Yi Wang
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Feng Zhang
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Wei Zhang
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Jiangqiang Xiao
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Guifang Xu
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Ying Lv
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Xiaoping Zou
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
| | - Yuzheng Zhuge
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China.
| | - Bin Zhang
- Department of Gastroenterology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China; Department of Gastroenterology, Gaochun People's Hospital, Nanjing, Jiangsu, China; Department of Gastroenterology, Yining People's Hospital, Yining, China.
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Iarovaia OV, Ioudinkova ES, Velichko AK, Razin SV. Manipulation of Cellular Processes via Nucleolus Hijaking in the Course of Viral Infection in Mammals. Cells 2021; 10:cells10071597. [PMID: 34202380 PMCID: PMC8303250 DOI: 10.3390/cells10071597] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 12/16/2022] Open
Abstract
Due to their exceptional simplicity of organization, viruses rely on the resources, molecular mechanisms, macromolecular complexes, regulatory pathways, and functional compartments of the host cell for an effective infection process. The nucleolus plays an important role in the process of interaction between the virus and the infected cell. The interactions of viral proteins and nucleic acids with the nucleolus during the infection process are universal phenomena and have been described for almost all taxonomic groups. During infection, proteins of the nucleolus in association with viral components can be directly used for the processes of replication and transcription of viral nucleic acids and the assembly and transport of viral particles. In the course of a viral infection, the usurpation of the nucleolus functions occurs and the usurpation is accompanied by profound changes in ribosome biogenesis. Recent studies have demonstrated that the nucleolus is a multifunctional and dynamic compartment. In addition to the biogenesis of ribosomes, it is involved in regulating the cell cycle and apoptosis, responding to cellular stress, repairing DNA, and transcribing RNA polymerase II-dependent genes. A viral infection can be accompanied by targeted transport of viral proteins to the nucleolus, massive release of resident proteins of the nucleolus into the nucleoplasm and cytoplasm, the movement of non-nucleolar proteins into the nucleolar compartment, and the temporary localization of viral nucleic acids in the nucleolus. The interaction of viral and nucleolar proteins interferes with canonical and non-canonical functions of the nucleolus and results in a change in the physiology of the host cell: cell cycle arrest, intensification or arrest of ribosome biogenesis, induction or inhibition of apoptosis, and the modification of signaling cascades involved in the stress response. The nucleolus is, therefore, an important target during viral infection. In this review, we discuss the functional impact of viral proteins and nucleic acid interaction with the nucleolus during infection.
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Slomnicki LP, Chung DH, Parker A, Hermann T, Boyd NL, Hetman M. Ribosomal stress and Tp53-mediated neuronal apoptosis in response to capsid protein of the Zika virus. Sci Rep 2017; 7:16652. [PMID: 29192272 PMCID: PMC5709411 DOI: 10.1038/s41598-017-16952-8] [Citation(s) in RCA: 36] [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: 04/24/2017] [Accepted: 11/20/2017] [Indexed: 02/07/2023] Open
Abstract
We report here that in rat and human neuroprogenitor cells as well as rat embryonic cortical neurons Zika virus (ZIKV) infection leads to ribosomal stress that is characterized by structural disruption of the nucleolus. The anti-nucleolar effects were most pronounced in postmitotic neurons. Moreover, in the latter system, nucleolar presence of ZIKV capsid protein (ZIKV-C) was associated with ribosomal stress and apoptosis. Deletion of 22 C-terminal residues of ZIKV-C prevented nucleolar localization, ribosomal stress and apoptosis. Consistent with a casual relationship between ZIKV-C-induced ribosomal stress and apoptosis, ZIKV-C-overexpressing neurons were protected by loss-of-function manipulations targeting the ribosomal stress effector Tp53 or knockdown of the ribosomal stress mediator RPL11. Finally, capsid protein of Dengue virus, but not West Nile virus, induced ribosomal stress and apoptosis. Thus, anti-nucleolar and pro-apoptotic effects of protein C are flavivirus-species specific. In the case of ZIKV, capsid protein-mediated ribosomal stress may contribute to neuronal death, neurodevelopmental disruption and microcephaly.
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Affiliation(s)
- Lukasz P Slomnicki
- Kentucky Spinal Cord Injury Research Center and the Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, 40292, USA
| | - Dong-Hoon Chung
- Center of Predictive Medicine and the Department of Microbiology & Immunology, University of Louisville, Louisville, Kentucky, 40292, USA
| | - Austin Parker
- Kentucky Spinal Cord Injury Research Center and the Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, 40292, USA
| | - Taylor Hermann
- Kentucky Spinal Cord Injury Research Center and the Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, 40292, USA
| | - Nolan L Boyd
- Cardiovascular Innovation Institute and the Department of Physiology, University of Louisville, Louisville, Kentucky, 40292, USA
| | - Michal Hetman
- Kentucky Spinal Cord Injury Research Center and the Department of Neurological Surgery, University of Louisville, Louisville, Kentucky, 40292, USA.
- Pharmacology & Toxicology, University of Louisville, Louisville, Kentucky, 40292, USA.
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Xie X, Guo P, Yu H, Wang Y, Chen G. Ribosomal proteins: insight into molecular roles and functions in hepatocellular carcinoma. Oncogene 2017; 37:277-285. [PMID: 28945227 DOI: 10.1038/onc.2017.343] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/21/2017] [Accepted: 08/14/2017] [Indexed: 02/07/2023]
Abstract
Ribosomes, which are important sites for the synthesis of proteins related to expression and transmission of genetic information in humans, have a complex structure and diverse functions. They consist of a variety of ribosomal proteins (RPs), ribosomal RNAs (rRNAs) and small nucleolar RNAs. Owing to the involvement of ribosomes in many important biological processes of cells, their major components, rRNAs and RPs, have an important role in human diseases, including the initiation and evolvement of malignancies. However, the main mechanisms underlying the involvement of ribosomes in cancer remain unclear. This review describes the crucial role of ribosomes in various common malignant tumors; in particular, it examines the effects of RPs, including S6, the receptor for activated C-kinase and RPS15A, on the development and progression of hepatocellular carcinoma.
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Affiliation(s)
- X Xie
- Department of Hepatobiliary Surgery, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - P Guo
- Department of Hepatobiliary Surgery, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - H Yu
- Department of Hepatobiliary Surgery, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
| | - Y Wang
- Research Center of Evidence-Based Medicine and Clinical Epidemiology, School of Public Health and Management, Wenzhou Medical University, Wenzhou, China
| | - G Chen
- Department of Hepatobiliary Surgery, The First Affiliated Hospital, Wenzhou Medical University, Wenzhou, China
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Hepatitis C Virus-Induced Upregulation of MicroRNA miR-146a-5p in Hepatocytes Promotes Viral Infection and Deregulates Metabolic Pathways Associated with Liver Disease Pathogenesis. J Virol 2016; 90:6387-6400. [PMID: 27147737 DOI: 10.1128/jvi.00619-16] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 04/23/2016] [Indexed: 12/12/2022] Open
Abstract
UNLABELLED Hepatitis C virus (HCV)-induced chronic liver disease is a leading cause of hepatocellular carcinoma (HCC). However, the molecular mechanisms underlying HCC development following chronic HCV infection remain poorly understood. MicroRNAs (miRNAs) play an important role in homeostasis within the liver, and deregulation of miRNAs has been associated with liver disease, including HCC. While host miRNAs are essential for HCV replication, viral infection in turn appears to induce alterations of intrahepatic miRNA networks. Although the cross talk between HCV and liver cell miRNAs most likely contributes to liver disease pathogenesis, the functional involvement of miRNAs in HCV-driven hepatocyte injury and HCC remains elusive. Here we combined a hepatocyte-like cell-based model system, high-throughput small RNA sequencing, computational analysis, and functional studies to investigate HCV-miRNA interactions that may contribute to liver disease and HCC. Profiling analyses indicated that HCV infection differentially regulated the expression of 72 miRNAs by at least 2-fold, including miRNAs that were previously described to target genes associated with inflammation, fibrosis, and cancer development. Further investigation demonstrated that the miR-146a-5p level was consistently increased in HCV-infected hepatocyte-like cells and primary human hepatocytes, as well as in liver tissue from HCV-infected patients. Genome-wide microarray and computational analyses indicated that miR-146a-5p overexpression modulates pathways that are related to liver disease and HCC development. Furthermore, we showed that miR-146a-5p has a positive impact on late steps of the viral replication cycle, thereby increasing HCV infection. Collectively, our data indicate that the HCV-induced increase in miR-146a-5p expression both promotes viral infection and is relevant for pathogenesis of liver disease. IMPORTANCE HCV is a leading cause of chronic liver disease and cancer. However, how HCV induces liver cancer remains poorly understood. There is accumulating evidence that a viral cure does not eliminate the risk for HCC development. Thus, there is an unmet medical need to develop novel approaches to predict and prevent virus-induced HCC. miRNA expression is known to be deregulated in liver disease and cancer. Furthermore, miRNAs are essential for HCV replication, and HCV infection alters miRNA expression. However, how miRNAs contribute to HCV-driven pathogenesis remains elusive. Here we show that HCV induces miRNAs that may contribute to liver injury and carcinogenesis. The miR-146a-5p level was consistently increased in different cell-based models of HCV infection and in HCV patient-derived liver tissue. Furthermore, miR-146a-5p increased HCV infection. Collectively, our data are relevant to understanding viral pathogenesis and may open perspectives for novel biomarkers and prevention of virus-induced liver disease and HCC.
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Ouellet Lavallée G, Pearson A. Upstream binding factor inhibits herpes simplex virus replication. Virology 2015; 483:108-16. [PMID: 25965800 DOI: 10.1016/j.virol.2015.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Revised: 01/09/2015] [Accepted: 04/02/2015] [Indexed: 12/16/2022]
Abstract
Herpes simplex virus 1 (HSV-1) infection induces changes to the host cell nucleus including relocalization of the cellular protein Upstream Binding Factor (UBF) from the nucleolus to viral replication compartments (VRCs). Herein, we tested the hypothesis that UBF is recruited to VRCs to promote viral DNA replication. Surprisingly, infection of UBF-depleted HeLa cells with HSV-1 or HSV-2 produced higher viral titers compared to controls. Reduced expression of UBF also led to a progressive increase in the relative amount of HSV-1 DNA versus controls, and increased levels of HSV-1 ICP27 and TK mRNA and protein, regardless of whether viral DNA replication was inhibited or not. Our results suggest that UBF can inhibit gene expression from viral DNA prior to its replication. A similar but smaller effect on viral titers was observed in human foreskin fibroblasts. This is the first report of UBF having a restrictive effect on replication of a virus.
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Rajput P, Shukla SK, Kumar V. The HBx oncoprotein of hepatitis B virus potentiates cell transformation by inducing c-Myc-dependent expression of the RNA polymerase I transcription factor UBF. Virol J 2015; 12:62. [PMID: 25890091 PMCID: PMC4424551 DOI: 10.1186/s12985-015-0293-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/31/2015] [Indexed: 01/03/2023] Open
Abstract
Background The HBx oncoprotein of hepatitis B virus has been implicated in the development and progression of hepatocellular carcinoma (HCC). HBx engages multiple signalling and growth-promoting pathways to induce cell proliferation and enhance ribosome biogenesis. Interestingly, the levels of Upstream Binding Factor (UBF) required for rDNA transcription and ribosome biogenesis are found elevated in the HCC patients. However, the molecular mechanism of UBF overexpression under the HBx microenvironment and consequent cell transformation remains elusive. Methods The UBF gene expression was investigated after co-expressing HBx in immortalized human hepatocytes (IHH) and human hepatoma Huh7 cells. Gene expression analysis involved estimation of mRNA level by real-time PCR, western blotting of protein, chromatin immune-precipitation assay, BrdU incorporation assay and soft agar colony formation assay. UBF expression was also investigated in an HBx transgenic mouse model of HCC to get a better mechanistic insight under more physiological conditions. Results Ectopic expression of HBx in IHH as well as Huh7 cells led to a marked increase in UBF expression both at mRNA and protein levels. Elevated levels of UBF were also observed in the hepatic tumors of HBx transgenic mice. Our ChIP studies revealed a marked increase in the occupancy of c-Myc on the UBF gene promoter in the presence of HBx and increase in its transcription. Enhanced UBF expression under the HBx microenvironment led to a marked increase in cell proliferation and transformation of IHH cells. Conclusions Our study provides some compelling evidences in support of HBx-mediated increase in UBF levels that abets oncogenic onslaught in hepatic cells by increasing rDNA transcription and ribosome biogenesis. Electronic supplementary material The online version of this article (doi:10.1186/s12985-015-0293-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Pallavi Rajput
- Virology Group, International Centre for Genetic engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Surendra Kumar Shukla
- Virology Group, International Centre for Genetic engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| | - Vijay Kumar
- Virology Group, International Centre for Genetic engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
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Pentecost M, Vashisht AA, Lester T, Voros T, Beaty SM, Park A, Wang YE, Yun TE, Freiberg AN, Wohlschlegel JA, Lee B. Evidence for ubiquitin-regulated nuclear and subnuclear trafficking among Paramyxovirinae matrix proteins. PLoS Pathog 2015; 11:e1004739. [PMID: 25782006 PMCID: PMC4363627 DOI: 10.1371/journal.ppat.1004739] [Citation(s) in RCA: 48] [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: 07/28/2014] [Accepted: 02/10/2015] [Indexed: 11/24/2022] Open
Abstract
The paramyxovirus matrix (M) protein is a molecular scaffold required for viral morphogenesis and budding at the plasma membrane. Transient nuclear residence of some M proteins hints at non-structural roles. However, little is known regarding the mechanisms that regulate the nuclear sojourn. Previously, we found that the nuclear-cytoplasmic trafficking of Nipah virus M (NiV-M) is a prerequisite for budding, and is regulated by a bipartite nuclear localization signal (NLSbp), a leucine-rich nuclear export signal (NES), and monoubiquitination of the K258 residue within the NLSbp itself (NLSbp-lysine). To define whether the sequence determinants of nuclear trafficking identified in NiV-M are common among other Paramyxovirinae M proteins, we generated the homologous NES and NLSbp-lysine mutations in M proteins from the five major Paramyxovirinae genera. Using quantitative 3D confocal microscopy, we determined that the NES and NLSbp-lysine are required for the efficient nuclear export of the M proteins of Nipah virus, Hendra virus, Sendai virus, and Mumps virus. Pharmacological depletion of free ubiquitin or mutation of the conserved NLSbp-lysine to an arginine, which inhibits M ubiquitination, also results in nuclear and nucleolar retention of these M proteins. Recombinant Sendai virus (rSeV-eGFP) bearing the NES or NLSbp-lysine M mutants rescued at similar efficiencies to wild type. However, foci of cells expressing the M mutants displayed marked fusogenicity in contrast to wild type, and infection did not spread. Recombinant Mumps virus (rMuV-eGFP) bearing the homologous mutations showed similar defects in viral morphogenesis. Finally, shotgun proteomics experiments indicated that the interactomes of Paramyxovirinae M proteins are significantly enriched for components of the nuclear pore complex, nuclear transport receptors, and nucleolar proteins. We then synthesize our functional and proteomics data to propose a working model for the ubiquitin-regulated nuclear-cytoplasmic trafficking of cognate paramyxovirus M proteins that show a consistent nuclear trafficking phenotype. Elucidating virus-cell interactions is fundamental to understanding viral replication and identifying targets for therapeutic control of viral infection. Paramyxoviruses include human and animal pathogens of medical and agricultural significance. Their matrix (M) structural protein organizes virion assembly at the plasma membrane and mediates viral budding. While nuclear localization of M proteins has been described for some paramyxoviruses, the underlying mechanisms of nuclear trafficking and the biological relevance of this observation have remained largely unexamined. Through comparative analyses of M proteins across five Paramyxovirinae genera, we identify M proteins from at least three genera that exhibit similar nuclear trafficking phenotypes regulated by an NLSbp as well as an NES sequence within M that may mediate the interaction of M with host nuclear transport receptors. Additionally, a conserved lysine within the NLSbp of some M proteins is required for nuclear export by regulating M ubiquitination. Sendai virus engineered to express a ubiquitination-defective M does not produce infectious virus but instead displays extensive cell-cell fusion while M is retained in the nucleolus. Thus, some Paramyxovirinae M proteins undergo regulated and active nuclear and subnuclear transport, a prerequisite for viral morphogenesis, which also suggests yet to be discovered roles for M in the nucleus.
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Affiliation(s)
- Mickey Pentecost
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Ajay A. Vashisht
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Talia Lester
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Tim Voros
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Shannon M. Beaty
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Arnold Park
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Yao E. Wang
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Tatyana E Yun
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Alexander N. Freiberg
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - James A. Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
| | - Benhur Lee
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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WU LEI, HUI HUI, WANG LIJUAN, WANG HAO, LIU QIUFANG, HAN SUXIA. MicroRNA-326 functions as a tumor suppressor in colorectal cancer by targeting the nin one binding protein. Oncol Rep 2015; 33:2309-18. [DOI: 10.3892/or.2015.3840] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 02/27/2015] [Indexed: 11/05/2022] Open
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Dichamp I, Séité P, Agius G, Barbarin A, Beby-Defaux A. Human papillomavirus 16 oncoprotein E7 stimulates UBF1-mediated rDNA gene transcription, inhibiting a p53-independent activity of p14ARF. PLoS One 2014; 9:e96136. [PMID: 24798431 PMCID: PMC4010441 DOI: 10.1371/journal.pone.0096136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 04/03/2014] [Indexed: 11/18/2022] Open
Abstract
High-risk human papillomavirus oncoproteins E6 and E7 play a major role in HPV-related cancers. One of the main functions of E7 is the degradation of pRb, while E6 promotes the degradation of p53, inactivating the p14ARF-p53 pathway. pRb and p14ARF can repress ribosomal DNA (rDNA) transcription in part by targeting the Upstream Binding Factor 1 (UBF1), a key factor in the activation of RNA polymerase I machinery. We showed, through ectopic expression and siRNA silencing of p14ARF and/or E7, that E7 stimulates UBF1-mediated rDNA gene transcription, partly because of increased levels of phosphorylated UBF1, preventing the inhibitory function of p14ARF. Unexpectedly, activation of rDNA gene transcription was higher in cells co-expressing p14ARF and E7, compared to cells expressing E7 alone. We did not find a difference in P-UBF1 levels that could explain this data. However, p14ARF expression induced E7 to accumulate into the nucleolus, where rDNA transcription takes place, providing an opportunity for E7 to interact with nucleolar proteins involved in this process. GST-pull down and co-immunoprecipitation assays showed interactions between p14ARF, UBF1 and E7, although p14ARF and E7 are not able to directly interact. Co-expression of a pRb-binding-deficient mutant (E7C24G) and p14ARF resulted in EC24G nucleolar accumulation, but not in a significant higher activation of rDNA transcription, suggesting that the inactivation of pRb is involved in this phenomenon. Thus, p14ARF fails to prevent E7-mediated UBF1 phosphorylation, but could facilitate nucleolar pRb inactivation by targeting E7 to the nucleolus. While others have reported that p19ARF, the mouse homologue of p14ARF, inhibits some functions of E7, we showed that E7 inhibits a p53-independent function of p14ARF. These results point to a mutually functional interaction between p14ARF and E7 that might partly explain why the sustained p14ARF expression observed in most cervical pre-malignant lesions and malignancies may be ineffective.
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Affiliation(s)
- Isabelle Dichamp
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
| | - Paule Séité
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
| | - Gérard Agius
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
| | - Alice Barbarin
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
| | - Agnès Beby-Defaux
- Unité de Virologie, Centre Hospitalier Universitaire de Poitiers, Faculté de Médecine et Pharmacie, Poitiers, France
- Equipe Emergente 2RCT «Récepteurs, Régulations, Cellules Tumorales», Université de Poitiers, Poitiers, France
- * E-mail:
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11
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Interaction of Hepatitis C Viral Proteins with Cellular Oncoproteins in the Induction of Liver Cancer. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/351407] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Hepatitis C virus infection is a major health problem all over the world. A large proportion of patients infected by HCV develop liver cirrhosis or cancer. However, the mechanism(s) remain to be elucidated. Since HCV does not carry any known oncogene, it is thought that interaction between virally encoded proteins and host proteins is responsible for carcinogenesis. Many crucial interactions between HCV-encoded proteins and host proteins have been reported. In this review we focus on the interaction of viral proteins with important regulators of cell cycle—oncoproteins YB-1, p53, and cyclin D1—which play a major role in cell proliferation, apoptosis, DNA repair, and genomic stability. Genetic variants of HCV accumulate in patients and alter these interactions of host cell proteins. It is a battle between the virus and host and the final outcome depends on the winner; if the host succeeds in clearing the virus the patient may not develop serious liver diseases. On the other hand, if the virus dominates by evolving quasispecies which code for altered proteins that interact differently with host proteins, or induce mutations in host protooncogenes, then the patient may develop liver cirrhosis and/or liver cancer.
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Downregulation of NOB1 suppresses the proliferation and tumor growth of non-small cell lung cancer in vitro and in vivo. Oncol Rep 2014; 31:1271-6. [PMID: 24452698 DOI: 10.3892/or.2014.2991] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 01/08/2014] [Indexed: 11/05/2022] Open
Abstract
Non-small cell lung cancer (NSCLC) is a lethal disease due to the absence of effective diagnostic biomarkers and therapeutic targets. Therefore, novel molecular targets are critically needed to formulate new approaches for this devastating disease. In the present study, using quantitive real-time PCR and immunohistochemistry. we initially found that expression of the ribosome assembly factor NIN/RPN12 binding protein (NOB1) was elevated in the majority of NSCLC tissues when compared to that in the normal lung tissue counterparts, and its expression level was correlated with key pathological characteristics including tumor differentiation, stage and metastasis. Then, the recombinant lentiviral shRNA expression vector carrying NOB1 was constructed and infected into the human NSCLC A549 cell line. Cell proliferation, cell apoptosis, cell cycle distribution and colony formation ability in A549 cells were assessed following downregulation of NOB1 by siRNA. In addition, tumor growth ability in nude mice was evaluated to define the function of NOB1 in cell transformation and tumorigenesis. It was found that downregulation of NOB1 expression using the RNA silencing approach in A549 tumor cells significantly suppressed the proliferation and colony formation ability, and induced tumor apoptosis in vitro. Tumor growth was also suppressed in vivo. These data suggest that NOB1 is an important regulator of the tumorigenic properties of human NSCLC and may be used as a new promising diagnostic biomarker and a potential anticancer therapeutic target for NSCLC.
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Attenuation of 40S ribosomal subunit abundance differentially affects host and HCV translation and suppresses HCV replication. PLoS Pathog 2012; 8:e1002766. [PMID: 22792060 PMCID: PMC3394201 DOI: 10.1371/journal.ppat.1002766] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 05/07/2012] [Indexed: 01/13/2023] Open
Abstract
For Hepatitis C virus (HCV), initiation of translation is cap-independently mediated by its internal ribosome entry site (IRES). Unlike other IRES-containing viruses that shut off host cap-dependent translation, translation of HCV coexists with that of the host. How HCV IRES-mediated translation is regulated in the infected cells remains unclear. Here, we show that the intracellular level of 40S ribosomal subunit plays a key role in facilitating HCV translation over host translation. In a loss-of-function screen, we identified small subunit ribosomal protein 6 (RPS6) as an indispensable host factor for HCV propagation. Knockdown of RPS6 selectively repressed HCV IRES-mediated translation, but not general translation. Such preferential suppression of HCV translation correlated well with the reduction of the abundance of 40S ribosomal subunit following knockdown of RPS6 or other RPS genes. In contrast, reduction of the amount of ribosomal proteins of the 60S subunit did not produce similar effects. Among the components of general translation machineries, only knockdowns of RPS genes caused inhibitory effects on HCV translation, pointing out the unique role of 40S subunit abundance in HCV translation. This work demonstrates an unconventional notion that the translation initiation of HCV and host possess different susceptibility toward reduction of 40S ribosomal subunit, and provides a model of selective modulation of IRES-mediated translation through manipulating the level of 40S subunit.
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Yoshikawa H, Komatsu W, Hayano T, Miura Y, Homma K, Izumikawa K, Ishikawa H, Miyazawa N, Tachikawa H, Yamauchi Y, Isobe T, Takahashi N. Splicing factor 2-associated protein p32 participates in ribosome biogenesis by regulating the binding of Nop52 and fibrillarin to preribosome particles. Mol Cell Proteomics 2011; 10:M110.006148. [PMID: 21536856 DOI: 10.1074/mcp.m110.006148] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ribosome biogenesis starts with transcription of the large ribosomal RNA precursor (47S pre-rRNA), which soon combines with numerous factors to form the 90S pre-ribosome in the nucleolus. Although the subsequent separation of the pre-90S particle into pre-40S and pre-60S particles is critical for the production process of mature small and large ribosomal subunits, its molecular mechanisms remain undetermined. Here, we present evidence that p32, fibrillarin (FBL), and Nop52 play key roles in this separation step. Mass-based analyses combined with immunoblotting showed that p32 associated with 155 proteins including 31 rRNA-processing factors (of which nine were components of small subunit processome, and six were those of RIX1 complex), 13 chromatin remodeling components, and six general transcription factors required for RNA polymerase III-mediated transcription. Of these, a late rRNA-processing factor Nop52 interacted directly with p32. Immunocytochemical analyses demonstrated that p32 colocalized with an early rRNA-processing factor FBL or Nop52 in the nucleolus and Cajal bodies, but was excluded from the nucleolus after actinomycin D treatment. p32 was present in the pre-ribosomal fractions prepared by cell fractionation or separated by ultracentrifugation of the nuclear extract. p32 also associated with pre-rRNAs including 47S/45S and 32S pre-rRNAs. Furthermore, knockdown of p32 with a small interfering RNA slowed the early processing from 47S/45S pre-rRNAs to 18S rRNA and 32S pre-rRNA. Finally, Nop52 was found to compete with FBL for binding to p32 probably in the nucleolus. Given the fact that FBL and Nop52 are associated with pre-ribosome particles distinctly different from each other, we suggest that p32 is a new rRNA maturation factor involved in the remodeling from pre-90S particles to pre-40S and pre-60S particles that requires the exchange of FBL for Nop52.
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Affiliation(s)
- Harunori Yoshikawa
- Department of Applied Life Science, United Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu-shi, Tokyo 183-8509, Japan
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Zhang D, Feng GH. Advances in research of interaction between hepatitis C virus nonstructural proteins and host proteins. Shijie Huaren Xiaohua Zazhi 2011; 19:161-169. [DOI: 10.11569/wcjd.v19.i2.161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatitis C virus (HCV) is another common cause of chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma after hepatitis B virus (HBV). Up to now, the mechanisms by which HCV promotes persistent infection and cancer remain unclear, and there are neither effective drugs nor vaccines against HCV available. Interaction between virus proteins and host proteins is a hot topic in research of the pathogenesis of viral hepatitis. Recent research shows that interaction between HCV nonstructural proteins and host proteins has an important impact on viral replication, carcinogenesis, interferon resistance, and disorders of glycometabolism and lipid metabolism. This paper summarizes the recent advances in research of interaction between HCV nonstructural proteins and host proteins.
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Bishop-Lilly KA, Turell MJ, Willner KM, Butani A, Nolan NME, Lentz SM, Akmal A, Mateczun A, Brahmbhatt TN, Sozhamannan S, Whitehouse CA, Read TD. Arbovirus detection in insect vectors by rapid, high-throughput pyrosequencing. PLoS Negl Trop Dis 2010; 4:e878. [PMID: 21085471 PMCID: PMC2976685 DOI: 10.1371/journal.pntd.0000878] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2010] [Accepted: 10/08/2010] [Indexed: 02/08/2023] Open
Abstract
Background Despite the global threat caused by arthropod-borne viruses, there is not an efficient method for screening vector populations to detect novel viral sequences. Current viral detection and surveillance methods based on culture can be costly and time consuming and are predicated on prior knowledge of the etiologic agent, as they rely on specific oligonucleotide primers or antibodies. Therefore, these techniques may be unsuitable for situations when the causative agent of an outbreak is unknown. Methodology/Principal Findings In this study we explored the use of high-throughput pyrosequencing for surveillance of arthropod-borne RNA viruses. Dengue virus, a member of the positive strand RNA Flavivirus family that is transmitted by several members of the Aedes genus of mosquitoes, was used as a model. Aedes aegypti mosquitoes experimentally infected with dengue virus type 1 (DENV-1) were pooled with noninfected mosquitoes to simulate samples derived from ongoing arbovirus surveillance programs. Using random-primed methods, total RNA was reverse-transcribed and resulting cDNA subjected to 454 pyrosequencing. Conclusions/Significance In two types of samples, one with 5 adult mosquitoes infected with DENV-1- and the other with 1 DENV-1 infected mosquito and 4 noninfected mosquitoes, we identified DENV-1 DNA sequences. DENV-1 sequences were not detected in an uninfected control pool of 5 adult mosquitoes. We calculated the proportion of the Ae. aegypti metagenome contributed by each infecting Dengue virus genome (pIP), which ranged from 2.75×10−8 to 1.08×10−7. DENV-1 RNA was sufficiently concentrated in the mosquito that its detection was feasible using current high-throughput sequencing instrumentation. We also identified some of the components of the mosquito microflora on the basis of the sequence of expressed RNA. This included members of the bacterial genera Pirellula and Asaia, various fungi, and a potentially uncharacterized mycovirus. Traditional methods for virus detection often rely on specific attributes, such as DNA sequences, of the viruses and therefore they not only require a priori knowledge of the agent in question, but they also are generally very specific in nature, capable of detecting viruses only from within a specific family, for example. Nextgen sequencing shows much promise for detection/diagnostic applications because of its ever-increasing throughput, decreasing cost, and unbiased nature. We investigated the applicability of 454 pyrosequencing for viral surveillance of insect populations, using Aedes aegypti mosquitoes experimentally inoculated with Dengue virus type 1 (DENV-1) and calculated what proportion of the total nucleic acid from crushed mosquitoes was contributed by the virus. We concluded that 454 pyrosequencing is capable of detecting even very small amounts of a known virus from within a pool of infected and noninfected mosquitoes, but for the amount of sequencing reads required to detect the virus, this technique may currently be too cost-prohibitive for use in large-scale surveillance efforts. Interesting byproducts of our study included a glimpse into what symbiotic organisms Ae. aegypti may harbor, as well as what genes may be differentially expressed in a DENV-1-infected versus noninfected mosquito.
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Affiliation(s)
- Kimberly A Bishop-Lilly
- Biological Defense Research Directorate, Naval Medical Research Center, Silver Spring, Maryland, USA.
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Production of infectious hepatitis C virus by using RNA polymerase I-mediated transcription. J Virol 2010; 84:5824-35. [PMID: 20237083 DOI: 10.1128/jvi.02397-09] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this study, we used an RNA polymerase I (Pol I) transcription system for development of a reverse genetics protocol to produce hepatitis C virus (HCV), which is an uncapped positive-strand RNA virus. Transfection with a plasmid harboring HCV JFH-1 full-length cDNA flanked by a Pol I promoter and Pol I terminator yielded an unspliced RNA with no additional sequences at either end, resulting in efficient RNA replication within the cytoplasm and subsequent production of infectious virions. Using this technology, we developed a simple replicon trans-packaging system, in which transient transfection of two plasmids enables examination of viral genome replication and virion assembly as two separate steps. In addition, we established a stable cell line that constitutively produces HCV with a low mutation frequency of the viral genome. The effects of inhibitors of N-linked glycosylation on HCV production were evaluated using this cell line, and the results suggest that certain step(s), such as virion assembly, intracellular trafficking, and secretion, are potentially up- and downregulated according to modifications of HCV envelope protein glycans. This Pol I-based HCV expression system will be beneficial for a high-throughput antiviral screening and vaccine discovery programs.
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Liu X, Wang T, Wakita T, Yang W. Systematic identification of microRNA and messenger RNA profiles in hepatitis C virus-infected human hepatoma cells. Virology 2009; 398:57-67. [PMID: 20006370 DOI: 10.1016/j.virol.2009.11.036] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 11/02/2009] [Accepted: 11/20/2009] [Indexed: 02/06/2023]
Abstract
In order to investigate the global and dynamic host microRNAs (miRNAs)/messenger RNAs (mRNAs) expression alteration during in vitro acute HCV infection, a comprehensive microarray analysis was performed using human hepatoma cells. Totally, 108 human miRNAs and 1247 mRNAs were identified whose expression levels changed for more than 2.0-fold in response to HCV infection. Upon HCV infection, signature from the unique miRNA expression pattern reflected the involvement of miRNA-regulated host cellular physiology and antiviral mechanism, whereas a preponderance of differentially regulated genes associated with metabolism, cell growth, apoptosis and cytokine/chemokine pathways. Furthermore, a reverse regulatory association of differentially expressed miRNAs and their predicted targets was constructed. Finally, the differentially expressed miRNAs such as miR-24, miR-149, miR-638 and miR-1181 were identified to be involved in HCV entry, replication and propagation. These results suggest that combined miRNA and mRNA profiling may have superior potential as a diagnostic and mechanistic feature in HCV infection.
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Affiliation(s)
- Xiuying Liu
- State Key Laboratory for Molecular Virology and Genetic Engineering, Institute of Pathogen Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, 6 Rong Jing Dong Jie, Beijing 100176, China
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Abstract
Although there is strong evidence that hepatitis C virus (HCV) is one of the leading causes of hepatocellular carcinoma (HCC), there is still much to understand regarding the mechanism of HCV-induced transformation. While liver fibrosis resulting from long-lasting chronic inflammation and liver regeneration resulting from immune-mediated cell death are likely factors that contribute to the development of HCC, the direct role of HCV proteins remains to be determined. In vitro studies have shown that HCV expression may interfere with cellular functions that are important for cell differentiation and cell growth. However, most studies were performed in artificial models which can only give clues for potential mechanisms that need to be confirmed in more relevant models. Furthermore, the difficulty to identify HCV proteins and infected liver cells in patients, contributes to the complexity of our current understanding. For these reasons, there is currently very little experimental evidence for a direct oncogenic role of HCV. Further studies are warranted to clarify these issues.
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Affiliation(s)
- Birke Bartosch
- INSERM, U871, 151 Cours Albert Thomas, 69003 Lyon, France
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