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Tang W, Zhou W, Ji M, Yang X. Role of STING in the treatment of non-small cell lung cancer. Cell Commun Signal 2024; 22:202. [PMID: 38566036 PMCID: PMC10986073 DOI: 10.1186/s12964-024-01586-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Accepted: 03/23/2024] [Indexed: 04/04/2024] Open
Abstract
Non-small cell lung cancer (NSCLC) is a prevalent form of lung cancer. Patients with advanced NSCLC are currently being treated with various therapies, including traditional radiotherapy, chemotherapy, molecular targeted therapies and immunotherapy. However, a considerable proportion of advance patients who cannot benefit from them. Consequently, it is essential to identify a novel research target that offers an encouraging perspective. The stimulator of interferon genes (STING) has emerged as such a target. At present, it is confirmed that activating STING in NSCLC tumor cells can impede the proliferation and metastasis of dormant tumor cells. This review focuses on the role of STING in NSCLC treatment and the factors influencing its activation. Additionally, it explores the correlation between STING activation and diverse therapy modalities for NSCLC, such as radiotherapy, chemotherapy, molecular targeted therapies and immunotherapy. Furthermore, it proposes the prospect of innovative therapy methods involving nanoparticles, with the aim of using the features of STING to develop more strategies for NSCLC therapy.
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Affiliation(s)
- Wenhua Tang
- Departments of Oncology, The Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, China
| | - Wenjie Zhou
- Departments of Oncology, The Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, China
| | - Mei Ji
- Departments of Oncology, The Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, China
| | - Xin Yang
- Departments of Oncology, The Third Affiliated Hospital of Soochow University, 185 Juqian Street, Changzhou, 213003, China.
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2
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Zhang R, Karijolich J. RNA recognition by PKR during DNA virus infection. J Med Virol 2024; 96:e29424. [PMID: 38285432 PMCID: PMC10832991 DOI: 10.1002/jmv.29424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/30/2024]
Abstract
Protein kinase R (PKR) is a double-stranded RNA (dsRNA) binding protein that plays a crucial role in innate immunity during viral infection and can restrict both DNA and RNA viruses. The potency of its antiviral function is further reflected by the large number of viral-encoded PKR antagonists. However, much about the regulation of dsRNA accumulation and PKR activation during viral infection remains unknown. Since DNA viruses do not have an RNA genome or RNA replication intermediates like RNA viruses do, PKR-mediated dsRNA detection in the context of DNA virus infection is particularly intriguing. Here, we review the current state of knowledge regarding the regulation of PKR activation and its antagonism during infection with DNA viruses.
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Affiliation(s)
- Ruilin Zhang
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt Center for Immunobiology, Nashville. Nashville, TN 37232-2363, USA
| | - John Karijolich
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN 37232-2363, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt Center for Immunobiology, Nashville. Nashville, TN 37232-2363, USA
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3
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Ito T, Wuerth JD, Weber F. Protection of eIF2B from inhibitory phosphorylated eIF2: A viral strategy to maintain mRNA translation during the PKR-triggered integrated stress response. J Biol Chem 2023; 299:105287. [PMID: 37742919 PMCID: PMC10616414 DOI: 10.1016/j.jbc.2023.105287] [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: 04/11/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/26/2023] Open
Abstract
The integrated stress response (ISR) protects cells from a variety of insults. Once elicited (e.g., by virus infections), it eventually leads to the block of mRNA translation. Central to the ISR are the interactions between translation initiation factors eIF2 and eIF2B. Under normal conditions, eIF2 drives the initiation of protein synthesis through hydrolysis of GTP, which becomes replenished by the guanine nucleotide exchange factor eIF2B. The antiviral branch of the ISR is activated by the RNA-activated kinase PKR which phosphorylates eIF2, thereby converting it into an eIF2B inhibitor. Here, we describe the recently solved structures of eIF2B in complex with eIF2 and a novel escape strategy used by viruses. While unphosphorylated eIF2 interacts with eIF2B in its "productive" conformation, phosphorylated eIF2 [eIF2(αP)] engages a different binding cavity on eIF2B and forces it into the "nonproductive" conformation that prohibits guanine nucleotide exchange factor activity. It is well established that viruses express so-called PKR antagonists that interfere with double-strand RNA, PKR itself, or eIF2. However recently, three taxonomically unrelated viruses were reported to encode antagonists targeting eIF2B instead. For one antagonist, the S segment nonstructural protein of Sandfly fever Sicilian virus, atomic structures showed that it occupies the eIF2(αP)-binding cavity on eIF2B without imposing a switch to the nonproductive conformation. S segment nonstructural protein thus antagonizes the activity of PKR by protecting eIF2B from inhibition by eIF2(αP). As the ISR and specifically eIF2B are central to neuroprotection and a wide range of genetic and age-related diseases, these developments may open new possibilities for treatments.
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Affiliation(s)
- Takuhiro Ito
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics Research, Yokohama, Japan
| | | | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany.
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4
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Miranda J, Vázquez-Blomquist D, Bringas R, Fernandez-de-Cossio J, Palenzuela D, Novoa LI, Bello-Rivero I. A co-formulation of interferons alpha2b and gamma distinctively targets cell cycle in the glioblastoma-derived cell line U-87MG. BMC Cancer 2023; 23:806. [PMID: 37644431 PMCID: PMC10463508 DOI: 10.1186/s12885-023-11330-2] [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: 12/12/2022] [Accepted: 08/23/2023] [Indexed: 08/31/2023] Open
Abstract
BACKGROUND HeberFERON is a co-formulation of α2b and γ interferons, based on their synergism, which has shown its clinical superiority over individual interferons in basal cell carcinomas. In glioblastoma (GBM), HeberFERON has displayed promising preclinical and clinical results. This led us to design a microarray experiment aimed at identifying the molecular mechanisms involved in the distinctive effect of HeberFERON compared to the individual interferons in U-87MG model. METHODS Transcriptional expression profiling including a control (untreated) and three groups receiving α2b-interferon, γ-interferon and HeberFERON was performed using an Illumina HT-12 microarray platform. Unsupervised methods for gene and sample grouping, identification of differentially expressed genes, functional enrichment and network analysis computational biology methods were applied to identify distinctive transcription patterns of HeberFERON. Validation of most representative genes was performed by qPCR. For the cell cycle analysis of cells treated with HeberFERON for 24 h, 48 and 72 h we used flow cytometry. RESULTS The three treatments show different behavior based on the gene expression profiles. The enrichment analysis identified several mitotic cell cycle related events, in particular from prometaphase to anaphase, which are exclusively targeted by HeberFERON. The FOXM1 transcription factor network that is involved in several cell cycle phases and is highly expressed in GBMs, is significantly down regulated. Flow cytometry experiments corroborated the action of HeberFERON on the cell cycle in a dose and time dependent manner with a clear cellular arrest as of 24 h post-treatment. Despite the fact that p53 was not down-regulated, several genes involved in its regulatory activity were functionally enriched. Network analysis also revealed a strong relationship of p53 with genes targeted by HeberFERON. We propose a mechanistic model to explain this distinctive action, based on the simultaneous activation of PKR and ATF3, p53 phosphorylation changes, as well as its reduced MDM2 mediated ubiquitination and export from the nucleus to the cytoplasm. PLK1, AURKB, BIRC5 and CCNB1 genes, all regulated by FOXM1, also play central roles in this model. These and other interactions could explain a G2/M arrest and the effect of HeberFERON on the proliferation of U-87MG. CONCLUSIONS We proposed molecular mechanisms underlying the distinctive behavior of HeberFERON compared to the treatments with the individual interferons in U-87MG model, where cell cycle related events were highly relevant.
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Affiliation(s)
- Jamilet Miranda
- Bioinformatics Group, Center for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba.
| | - Dania Vázquez-Blomquist
- Pharmacogenomics Group, Center for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba.
| | - Ricardo Bringas
- Bioinformatics Group, Center for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba
| | | | - Daniel Palenzuela
- Pharmacogenomics Group, Center for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba
| | - Lidia I Novoa
- Pharmacogenomics Group, Center for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba
| | - Iraldo Bello-Rivero
- Clinical Assays Division, Center for Genetic Engineering and Biotechnology (CIGB), Havana, Cuba
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5
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Huang J, Yu Z, Li X, Yang M, Fang Q, Li Z, Wang C, Chen T, Cao X. E3 ligase HECTD3 promotes RNA virus replication and virus-induced inflammation via K33-linked polyubiquitination of PKR. Cell Death Dis 2023; 14:396. [PMID: 37402711 DOI: 10.1038/s41419-023-05923-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 06/17/2023] [Accepted: 06/23/2023] [Indexed: 07/06/2023]
Abstract
Uncontrolled viral replication and excessive inflammation are the main causes of death in the host infected with virus. Hence inhibition of intracellular viral replication and production of innate cytokines, which are the key strategies of hosts to fight virus infections, need to be finely tuned to eliminate viruses while avoid harmful inflammation. The E3 ligases in regulating virus replication and subsequent innate cytokines production remain to be fully characterized. Here we report that the deficiency of the E3 ubiquitin-protein ligase HECTD3 results in accelerated RNA virus clearance and reduced inflammatory response both in vitro and in vivo. Mechanistically, HECTD3 interacts with dsRNA-dependent protein kinase R (PKR) and mediates Lys33-linkage of PKR, which is the first non-proteolytic ubiquitin modification for PKR. This process disrupts the dimerization and phosphorylation of PKR and subsequent EIF2α activation, which results in the acceleration of virus replication, but promotes the formation of PKR-IKK complex and subsequent inflammatory response. The finding suggests HECTD3 is the potential therapeutic target for simultaneously restraining RNA virus replication and virus-induced inflammation once pharmacologically inhibited.
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Affiliation(s)
- Jiaying Huang
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China
| | - Zhou Yu
- National Key Laboratory of Immunity and Inflammation, Suzhou Institute of Systems Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Suzhou, 215123, Jiangsu, China.
- National Key Laboratory of Immunity and Inflammation & Institute of Immunology, Navy Medical University, Shanghai, 200433, China.
| | - Xuelian Li
- National Key Laboratory of Immunity and Inflammation, Suzhou Institute of Systems Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Suzhou, 215123, Jiangsu, China
| | - Mingjin Yang
- National Key Laboratory of Immunity and Inflammation & Institute of Immunology, Navy Medical University, Shanghai, 200433, China
| | - Qian Fang
- National Key Laboratory of Immunity and Inflammation & Institute of Immunology, Navy Medical University, Shanghai, 200433, China
| | - Zheng Li
- National Key Laboratory of Immunity and Inflammation & Institute of Immunology, Navy Medical University, Shanghai, 200433, China
| | - Chunmei Wang
- National Key Laboratory of Immunity and Inflammation, Suzhou Institute of Systems Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Suzhou, 215123, Jiangsu, China
| | - Taoyong Chen
- National Key Laboratory of Immunity and Inflammation & Institute of Immunology, Navy Medical University, Shanghai, 200433, China
| | - Xuetao Cao
- Institute of Immunology, Zhejiang University School of Medicine, Hangzhou, 310058, China.
- National Key Laboratory of Immunity and Inflammation, Suzhou Institute of Systems Medicine, Chinese Academy of Medical Sciences & Peking Union Medical College, Suzhou, 215123, Jiangsu, China.
- National Key Laboratory of Immunity and Inflammation & Institute of Immunology, Navy Medical University, Shanghai, 200433, China.
- Institute of Immunology, College of Life Science, Nankai University, Tianjin, 300071, China.
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6
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Qin S, Kitty I, Hao Y, Zhao F, Kim W. Maintaining Genome Integrity: Protein Kinases and Phosphatases Orchestrate the Balancing Act of DNA Double-Strand Breaks Repair in Cancer. Int J Mol Sci 2023; 24:10212. [PMID: 37373360 DOI: 10.3390/ijms241210212] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/13/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
DNA double-strand breaks (DSBs) are the most lethal DNA damages which lead to severe genome instability. Phosphorylation is one of the most important protein post-translation modifications involved in DSBs repair regulation. Kinases and phosphatases play coordinating roles in DSB repair by phosphorylating and dephosphorylating various proteins. Recent research has shed light on the importance of maintaining a balance between kinase and phosphatase activities in DSB repair. The interplay between kinases and phosphatases plays an important role in regulating DNA-repair processes, and alterations in their activity can lead to genomic instability and disease. Therefore, study on the function of kinases and phosphatases in DSBs repair is essential for understanding their roles in cancer development and therapeutics. In this review, we summarize the current knowledge of kinases and phosphatases in DSBs repair regulation and highlight the advancements in the development of cancer therapies targeting kinases or phosphatases in DSBs repair pathways. In conclusion, understanding the balance of kinase and phosphatase activities in DSBs repair provides opportunities for the development of novel cancer therapeutics.
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Affiliation(s)
- Sisi Qin
- Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Ichiwa Kitty
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-Bio Science (SIMS), Soonchunhyang University, Cheonan 31151, Chungcheongnam-do, Republic of Korea
| | - Yalan Hao
- Analytical Instrumentation Center, Hunan University, Changsha 410082, China
| | - Fei Zhao
- College of Biology, Hunan University, Changsha 410082, China
| | - Wootae Kim
- Department of Integrated Biomedical Science, Soonchunhyang Institute of Medi-Bio Science (SIMS), Soonchunhyang University, Cheonan 31151, Chungcheongnam-do, Republic of Korea
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7
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Salucci S, Bavelloni A, Stella AB, Fabbri F, Vannini I, Piazzi M, Volkava K, Scotlandi K, Martinelli G, Faenza I, Blalock W. The Cytotoxic Effect of Curcumin in Rhabdomyosarcoma Is Associated with the Modulation of AMPK, AKT/mTOR, STAT, and p53 Signaling. Nutrients 2023; 15:nu15030740. [PMID: 36771452 PMCID: PMC9920154 DOI: 10.3390/nu15030740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/11/2023] [Accepted: 01/28/2023] [Indexed: 02/04/2023] Open
Abstract
Approximately 7% of cancers arising in children and 1% of those arising in adults are soft tissue sarcomas (STS). Of these malignancies, rhabdomyosarcoma (RMS) is the most common. RMS survival rates using current therapeutic protocols have remained largely unchanged in the past decade. Thus, it is imperative that the main molecular drivers in RMS tumorigenesis are defined so that more precise, effective, and less toxic therapies can be designed. Curcumin, a common herbal supplement derived from plants of the Curcuma longa species, has an exceptionally low dietary biotoxicity profile and has demonstrated anti-tumorigenic benefits in vitro. In this study, the anti-tumorigenic activity of curcumin was assessed in rhabdomyosarcoma cell lines and used to identify the major pathways responsible for curcumin's anti-tumorigenic effects. Curcumin treatment resulted in cell cycle arrest, inhibited cell migration and colony forming potential, and induced apoptotic cell death. Proteome profiler array analysis demonstrated that curcumin treatment primarily influenced flux through the AKT-mammalian target of rapamycin (mTOR), signal transducer and activator of transcription (STAT), AMP-dependent kinase (AMPK), and p53 associated pathways in a rhabdomyosarcoma subtype-specific manner. Thus, the strategic, combinational therapeutic targeting of these pathways may present the best option to treat this group of tumors.
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Affiliation(s)
- Sara Salucci
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), Università di Bologna, 40126 Bologna, Italy
| | - Alberto Bavelloni
- Laboratorio di Oncologia Sperimentale, IRCCS, Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Anna Bartoletti Stella
- Dipartimento di Medicina Specialistica, Diagnostica e Sperimentale (DIMES), Università di Bologna, 40126 Bologna, Italy
| | - Francesco Fabbri
- Laboratorio di Bioscienze, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy
| | - Ivan Vannini
- Laboratorio di Bioscienze, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy
| | - Manuela Piazzi
- ‘‘Luigi Luca Cavalli-Sforza’’ Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerca (IGM-CNR), 40136 Bologna, Italy
- IRCCS, Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Karyna Volkava
- Dipartimento di Farmacia e Biotecnologie (FABIT), Università di Bologna, 40126 Bologna, Italy
| | - Katia Scotlandi
- Laboratorio di Oncologia Sperimentale, IRCCS, Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Giovanni Martinelli
- Laboratorio di Bioscienze, IRCCS Istituto Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy
| | - Irene Faenza
- Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), Università di Bologna, 40126 Bologna, Italy
- Correspondence: (I.F.); (W.B.)
| | - William Blalock
- ‘‘Luigi Luca Cavalli-Sforza’’ Istituto di Genetica Molecolare, Consiglio Nazionale delle Ricerca (IGM-CNR), 40136 Bologna, Italy
- IRCCS, Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
- Correspondence: (I.F.); (W.B.)
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8
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Zhou L, Cheng A, Wang M, Wu Y, Yang Q, Tian B, Ou X, Sun D, Zhang S, Mao S, Zhao XX, Huang J, Gao Q, Zhu D, Jia R, Liu M, Chen S. Mechanism of herpesvirus protein kinase UL13 in immune escape and viral replication. Front Immunol 2022; 13:1088690. [PMID: 36531988 PMCID: PMC9749954 DOI: 10.3389/fimmu.2022.1088690] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 11/15/2022] [Indexed: 12/05/2022] Open
Abstract
Upon infection, the herpes viruses create a cellular environment suitable for survival, but innate immunity plays a vital role in cellular resistance to viral infection. The UL13 protein of herpesviruses is conserved among all herpesviruses and is a serine/threonine protein kinase, which plays a vital role in escaping innate immunity and promoting viral replication. On the one hand, it can target various immune signaling pathways in vivo, such as the cGAS-STING pathway and the NF-κB pathway. On the other hand, it phosphorylates regulatory many cellular and viral proteins for promoting the lytic cycle. This paper reviews the research progress of the conserved herpesvirus protein kinase UL13 in immune escape and viral replication to provide a basis for elucidating the pathogenic mechanism of herpesviruses, as well as providing insights into the potential means of immune escape and viral replication of other herpesviruses that have not yet resolved the function of it.
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Affiliation(s)
- Lin Zhou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,*Correspondence: Mingshu Wang,
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xumin Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Xin-Xin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Juan Huang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China,Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, China,Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, China
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9
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Li L, Li P, Ma X, Zeng S, Peng Y, Zhang G. Therapeutic restoring p53 function with small molecule for oncogene-driven non-small cell lung cancer by targeting serine 392 phosphorylation. Biochem Pharmacol 2022; 203:115188. [PMID: 35902040 DOI: 10.1016/j.bcp.2022.115188] [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: 05/11/2022] [Revised: 07/05/2022] [Accepted: 07/20/2022] [Indexed: 12/01/2022]
Abstract
p53 inactivation by disabling its function is a hallmark in lung carcinomas, emphasizing the significance of restoring p53 function as an attractive therapeutic strategy. However, the clinical efficacy of existing p53 activators is limited due to their inability to effectively activate p53 within the tumors. Here, we established a p53 activator screening assay in EGFR-driven lung cancer cells and identified a small molecular, MX-C4, as a promising candidate. Using high throughput compound screening and combination analyses, we found that MX-C4 effectively promoted the phosphorylation of p53 at serine-392 (s392). It exhibited potent antitumor activity in a variety of cancer cell lines, but only limited toxicity to NCI-H1299 (p53-null) and normal cell lines such as LX2 and HL-7702. Overexpression of p53 in NCI-H1299 cells by a p53 expressing virus vector sensitized cells to MX-C4 treatment, suggesting a p53-dependent anticancer activity. Furthermore, we demonstrated that MX-C4 bound to p53 and exerted its anticancer activity through cell cycle arrest at G2/M phase and apoptosis induction. Mechanistic study indicated that p53 activation regulated cell cycle and cell survival related targets at protein levels. Moreover, p53 activation raised phospho-p53 translocation to mitochondria and subsequently reorganized the Bcl-xl-Bak complex, thus conformationally activating Bak and inducing apoptosis. It is noteworthy that MX-C4 could effectively activate p53 within the tumors in EGFR-driven xenograft models, where tumor was significantly suppressed without obvious toxicity. Our study identified a promising candidate for lung cancer therapy by restoring p53 function.
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Affiliation(s)
- Liangping Li
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China
| | - Pingping Li
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China
| | - Xuesong Ma
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China
| | - Shulan Zeng
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China.
| | - Yan Peng
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China.
| | - Guohai Zhang
- State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Ministry of Science and Technology of China, Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China.
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10
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Ou A, Zhao X, Lu Z. The potential roles of p53 signaling reactivation in pancreatic cancer therapy. Biochim Biophys Acta Rev Cancer 2022; 1877:188662. [PMID: 34861354 DOI: 10.1016/j.bbcan.2021.188662] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/24/2021] [Accepted: 11/24/2021] [Indexed: 12/25/2022]
Abstract
Globally, pancreatic cancer (PC) is a common and highly malignant gastrointestinal tumor that is characterized by an insidious onset and ready metastasis and recurrence. Over recent decades, the incidence of PC has been increasing on an annual basis; however, the pathogenesis of this condition remains enigmatic. PC is not sensitive to radio- or chemotherapy, and except for early surgical resection, there is no curative treatment regime; consequently, the prognosis for patients with PC is extremely poor. Transcription factor p53 is known to play key roles in many important biological processes in vertebrates, including normal cell growth, differentiation, cell cycle progression, senescence, apoptosis, metabolism, and DNA damage repair. However, there is a significant paucity of basic and clinical studies to describe how p53 gene mutations or protein dysfunction facilitate the occurrence, progression, invasion, and resistance to therapy, of malignancies, including PC. Herein, we describe the involvement of p53 signaling reactivation in PC treatment as well as its underlying molecular mechanisms, thereby providing useful insights for targeting p53-related signal pathways in PC therapy.
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Affiliation(s)
- Aixin Ou
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang 110004, LN, China
| | - Xiangxuan Zhao
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang 110004, LN, China
| | - Zaiming Lu
- Department of Radiology, Shengjing Hospital of China Medical University, Shenyang 110004, LN, China.
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11
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Ou A, Zhao X, Lu Z. The potential roles of p53 signaling reactivation in pancreatic cancer therapy. Biochim Biophys Acta Rev Cancer 2022; 1877:188662. [DOI: doi10.1016/j.bbcan.2021.188662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
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12
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Yin L, Zeng Y, Zeng R, Chen Y, Wang TL, Rodabaugh KJ, Yu F, Natarajan A, Karpf AR, Dong J. Protein kinase RNA-activated controls mitotic progression and determines paclitaxel chemosensitivity through B-cell lymphoma 2 in ovarian cancer. Oncogene 2021; 40:6772-6785. [PMID: 34799660 PMCID: PMC8688329 DOI: 10.1038/s41388-021-02117-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/02/2021] [Accepted: 11/08/2021] [Indexed: 11/23/2022]
Abstract
Anti-tubulin agents, such as paclitaxel, have been used extensively for treatment of several types of cancer, including ovarian, lung, breast, and pancreatic cancers. Despite their wide use in cancer treatment, however, patient response is highly variable and drug resistance remains a major clinical issue. Protein kinase RNA-activated (PKR) plays a critical role in immune response to viral infection. We identified PKR as a phospho-protein in response to anti-tubulin agents and this phosphorylation occurs independent of its own kinase activity. PKR is phosphorylated by cyclin-dependent kinase 1 (CDK1) during anti-tubulin treatment and unperturbed mitosis and that PKR regulates mitotic progression in a phosphorylation-dependent manner. Furthermore, inactivation of PKR confers resistance to paclitaxel in ovarian and breast cancer cells in vitro and in vivo. PKR expression levels and activity are decreased in chemotherapeutic recurrent ovarian cancer patients. Mechanistically, our findings suggest that PKR controls paclitaxel chemosensitivity through repressing Bcl2 expression. Pharmacological inhibition of Bcl2 with FDA-approved agent venetoclax overcomes paclitaxel resistance in preclinical animal models of ovarian cancer. Our results suggest that PKR is a critical determinant of paclitaxel cytotoxicity and that PKR-Bcl2 axis as a potential therapeutic target for the treatment of recurrent drug-resistant ovarian tumors.
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Affiliation(s)
- Ling Yin
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
- State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, 510060, China
| | - Yongji Zeng
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Renya Zeng
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Yuanhong Chen
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Tian-Li Wang
- Department of Pathology and Sydney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, Baltimore, MD, 21205, USA
| | - Kerry J Rodabaugh
- Department of Gynecologic Oncology, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Fang Yu
- Department of Biostatistics, College of Public Health, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Amarnath Natarajan
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Adam R Karpf
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Jixin Dong
- Eppley Institute for Research in Cancer and Allied Diseases, Fred & Pamela Buffett Cancer Center, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
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13
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Abstract
Cells respond to viral infections through sensors that detect non-self-molecules, and through effectors, which can have direct antiviral activities or adapt cell physiology to limit viral infection and propagation. Eukaryotic translation initiation factor 2 alpha kinase 2, better known as PKR, acts as both a sensor and an effector in the response to viral infections. After sensing double-stranded RNA molecules in infected cells, PKR self-activates and majorly exerts its antiviral function by blocking the translation machinery and inducing apoptosis. The antiviral potency of PKR is emphasized by the number of strategies developed by viruses to antagonize the PKR pathway. In this review, we present an update on the diversity of such strategies, which range from preventing double-stranded RNA recognition upstream from PKR activation, to activating eIF2B downstream from PKR targets.
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Affiliation(s)
- Teresa Cesaro
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Thomas Michiels
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium
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14
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Song S, Shi Y, Wu W, Wu H, Chang L, Peng P, Zhang L, Fan J, Gu J, Ruan Y. Reticulon 3-mediated Chk2/p53 activation suppresses hepatocellular carcinogenesis and is blocked by hepatitis B virus. Gut 2021; 70:2159-2171. [PMID: 33303565 DOI: 10.1136/gutjnl-2020-321386] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/21/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Dysfunction of endoplasmic reticulum (ER) proteins is closely related to homeostasis disturbance and malignant transformation of hepatocellular carcinoma (HCC). Reticulons (RTN) are a family of ER-resident proteins critical for maintaining ER function. Nevertheless, the precise roles of RTN in HCC remain largely unclear. The aim of the study is to examine the effect of reticulon family member RTN3 on HCC development and explore the underlying mechanisms. DESIGN Clinical HCC samples were collected to assess the relationship between RTN3 expression and patients' outcome. HCC cell lines were employed to examine the effects of RTN3 on cellular proliferation, apoptosis and signal transduction in vitro. Nude mice model was used to detect the role of RTN3 in modulating tumour growth in vivo. RESULTS We found that RTN3 was highly expressed in normal hepatocytes but frequently downregulated in HCC. Low RTN3 expression predicted poor outcome in patients with HCC in TP53 gene mutation and HBV infection status-dependent manner. RTN3 restrained HCC growth and induced apoptosis by activating p53. Mechanism studies indicated that RTN3 facilitated p53 Ser392 phosphorylation via Chk2 and enhanced subsequent p53 nuclear localisation. RTN3 interacted with Chk2, recruited it to ER and promoted its activation in an ER calcium-dependent manner. Nevertheless, the tumour suppressive effects of RTN3 were abrogated in HBV-positive cells. HBV surface antigen competed with Chk2 for RTN3 binding and blocked RTN3-mediated Chk2/p53 activation. CONCLUSION The findings suggest that RTN3 functions as a novel suppressor of HCC by activating Chk2/p53 pathway and provide more clues to better understand the oncogenic effects of HBV.
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Affiliation(s)
- Shushu Song
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yinghong Shi
- Department of Liver Surgery, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Weicheng Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Hao Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Lei Chang
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Beijing Institute of Lifeomics, Beijing, China
| | - Peike Peng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Lei Zhang
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jia Fan
- Department of Liver Surgery, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jianxin Gu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China
| | - Yuanyuan Ruan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China
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15
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Li D, Xie L, Qiao Z, Mai S, Zhu J, Zhang F, Chen S, Li L, Shen F, Qin Y, Yao H, He S, Ma F. STING-mediated degradation of IFI16 negatively regulates apoptosis by inhibiting p53 phosphorylation at serine 392. J Biol Chem 2021; 297:100930. [PMID: 34216619 PMCID: PMC8326736 DOI: 10.1016/j.jbc.2021.100930] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 06/17/2021] [Accepted: 06/29/2021] [Indexed: 12/12/2022] Open
Abstract
Interferon-γ–inducible factor 16 (IFI16) triggers stimulator of interferon (IFN) genes (STING)–dependent type I IFN production during host antiviral immunity and facilitates p53-dependent apoptosis during suppressing tumorigenesis. We have previously reported that STING-mediated IFI16 degradation negatively regulates type I IFN production. However, it is unknown whether STING also suppresses IFI16/p53-dependent apoptosis via degradation of IFI16. Here, our results from flow cytometry apoptosis detection and immunoblot assays show that IFI16 and nutlin-3, a p53 pathway activator, synergistically induce apoptosis in U2OS and A549 cells. Protein kinase R–triggered phosphorylation of p53 at serine 392 is critical for the IFI16-p53–dependent apoptosis. However, overexpression of STING suppresses p53 serine 392 phosphorylation, p53 transcriptional activity, expression of p53 target genes, and p53-dependent mitochondrial depolarization and apoptosis. In summary, our current study demonstrates that STING-mediated IFI16 degradation negatively regulates IFI16-mediated p53-dependent apoptosis in osteosarcoma and non–small cell lung cancer cells, which suggests a protumorigenic role for STING in certain cancer types because of its potent ability to degrade upstream IFI16.
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Affiliation(s)
- Dapei Li
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China.
| | - Lifen Xie
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China
| | - Zigang Qiao
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China
| | - Sanyue Mai
- Department of Laboratory Medicine, 988 Central Hospital of People's Liberation Army, Zhengzhou, China
| | - Jingfei Zhu
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China
| | - Fan Zhang
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China
| | - Shengchuan Chen
- Suzhou Institute of Systems Medicine, Suzhou, China; Department of Hepatopancreatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Liang Li
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China; Department of Hepatopancreatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Fangrong Shen
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yanghua Qin
- Department of Laboratory Diagnosis, Changhai Hospital of the Second Military Medical University, Shanghai, China
| | - Haiping Yao
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China
| | - Sudan He
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China
| | - Feng Ma
- Center for Systems Medicine, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China; Suzhou Institute of Systems Medicine, Suzhou, China; Department of Hepatopancreatobiliary Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
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16
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Sadeq S, Al-Hashimi S, Cusack CM, Werner A. Endogenous Double-Stranded RNA. Noncoding RNA 2021; 7:15. [PMID: 33669629 PMCID: PMC7930956 DOI: 10.3390/ncrna7010015] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 02/07/2023] Open
Abstract
The birth of long non-coding RNAs (lncRNAs) is closely associated with the presence and activation of repetitive elements in the genome. The transcription of endogenous retroviruses as well as long and short interspersed elements is not only essential for evolving lncRNAs but is also a significant source of double-stranded RNA (dsRNA). From an lncRNA-centric point of view, the latter is a minor source of bother in the context of the entire cell; however, dsRNA is an essential threat. A viral infection is associated with cytoplasmic dsRNA, and endogenous RNA hybrids only differ from viral dsRNA by the 5' cap structure. Hence, a multi-layered defense network is in place to protect cells from viral infections but tolerates endogenous dsRNA structures. A first line of defense is established with compartmentalization; whereas endogenous dsRNA is found predominantly confined to the nucleus and the mitochondria, exogenous dsRNA reaches the cytoplasm. Here, various sensor proteins recognize features of dsRNA including the 5' phosphate group of viral RNAs or hybrids with a particular length but not specific nucleotide sequences. The sensors trigger cellular stress pathways and innate immunity via interferon signaling but also induce apoptosis via caspase activation. Because of its central role in viral recognition and immune activation, dsRNA sensing is implicated in autoimmune diseases and used to treat cancer.
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Affiliation(s)
| | | | | | - Andreas Werner
- Biosciences Institute, Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK; (S.S.); (S.A.-H.); (C.M.C.)
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17
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Alzhanova D, Corcoran K, Bailey AG, Long K, Taft-Benz S, Graham RL, Broussard GS, Heise M, Neumann G, Halfmann P, Kawaoka Y, Baric RS, Damania B, Dittmer DP. Novel modulators of p53-signaling encoded by unknown genes of emerging viruses. PLoS Pathog 2021; 17:e1009033. [PMID: 33411764 PMCID: PMC7790267 DOI: 10.1371/journal.ppat.1009033] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023] Open
Abstract
The p53 transcription factor plays a key role both in cancer and in the cell-intrinsic response to infections. The ORFEOME project hypothesized that novel p53-virus interactions reside in hitherto uncharacterized, unknown, or hypothetical open reading frames (orfs) of human viruses. Hence, 172 orfs of unknown function from the emerging viruses SARS-Coronavirus, MERS-Coronavirus, influenza, Ebola, Zika (ZIKV), Chikungunya and Kaposi Sarcoma-associated herpesvirus (KSHV) were de novo synthesized, validated and tested in a functional screen of p53 signaling. This screen revealed novel mechanisms of p53 virus interactions and two viral proteins KSHV orf10 and ZIKV NS2A binding to p53. Originally identified as the target of small DNA tumor viruses, these experiments reinforce the notion that all viruses, including RNA viruses, interfere with p53 functions. These results validate this resource for analogous systems biology approaches to identify functional properties of uncharacterized viral proteins, long non-coding RNAs and micro RNAs. New viruses are constantly emerging. The ORFEOME project was based on the hypothesis that every virus, regardless of its molecular makeup and biology should encode functions that intersect the p53 signaling network, since p53 guards the cell from genomic insults, of which depositing a foreign, viral nucleic acid is one. The result of the ORFEOME screen of proteins without any known function, of predicted open reading frames and of suspected non-coding RNAs is the identification of two viral proteins that interact with p53. The first one, orf10, is encoded by Kaposi Sarcoma-associated herpesvirus and the second one, NS2A, is encoded by the Zika virus.
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Affiliation(s)
- Dina Alzhanova
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kathleen Corcoran
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Aubrey G. Bailey
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Kristin Long
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Genetics, University of North Carolina at Chapel Hill, North Carolina, United States of America
| | - Sharon Taft-Benz
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Genetics, University of North Carolina at Chapel Hill, North Carolina, United States of America
| | - Rachel L. Graham
- Department of Epidemiology, University of North Carolina at Chapel Hill, North Carolina, United States of America
| | - Grant S. Broussard
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Mark Heise
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Genetics, University of North Carolina at Chapel Hill, North Carolina, United States of America
| | - Gabriele Neumann
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Peter Halfmann
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Yoshihiro Kawaoka
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ralph S. Baric
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Epidemiology, University of North Carolina at Chapel Hill, North Carolina, United States of America
| | - Blossom Damania
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Dirk P. Dittmer
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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18
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Romero-Medina MC, Venuti A, Melita G, Robitaille A, Ceraolo MG, Pacini L, Sirand C, Viarisio D, Taverniti V, Gupta P, Scalise M, Indiveri C, Accardi R, Tommasino M. Human papillomavirus type 38 alters wild-type p53 activity to promote cell proliferation via the downregulation of integrin alpha 1 expression. PLoS Pathog 2020; 16:e1008792. [PMID: 32813746 PMCID: PMC7458291 DOI: 10.1371/journal.ppat.1008792] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 08/31/2020] [Accepted: 07/08/2020] [Indexed: 12/28/2022] Open
Abstract
Tumor suppressors can exert pro-proliferation functions in specific contexts. In the beta human papillomavirus type 38 (HPV38) experimental model, the viral proteins E6 and E7 promote accumulation of a wild-type (WT) p53 form in human keratinocytes (HKs), promoting cellular proliferation. Inactivation of p53 by different means strongly decreases the proliferation of HPV38 E6/E7 HKs. This p53 form is phosphorylated at S392 by the double-stranded RNA-dependent protein kinase PKR, which is highly activated by HPV38. PKR-mediated S392 p53 phosphorylation promotes the formation of a p53/DNMT1 complex, which inhibits expression of integrin alpha 1 (ITGA1), a repressor of epidermal growth factor receptor (EGFR) signaling. Ectopic expression of ITGA1 in HPV38 E6/E7 HKs promotes EGFR degradation, inhibition of cellular proliferation, and cellular death. Itga1 expression was also inhibited in the skin of HPV38 transgenic mice that have an elevated susceptibility to UV-induced skin carcinogenesis. In summary, these findings reveal the existence of a specific WT p53 form that displays pro-proliferation properties.
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Affiliation(s)
- Maria Carmen Romero-Medina
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Assunta Venuti
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Giusi Melita
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Alexis Robitaille
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Maria Grazia Ceraolo
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Laura Pacini
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Cecilia Sirand
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Daniele Viarisio
- Deutsches Krebsforschungszentrum (DKFZ), Im Neuenheimer Feld, Heidelberg, Germany
| | - Valerio Taverniti
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Purnima Gupta
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Mariafrancesca Scalise
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Arcavacata di Rende, Italy
| | - Cesare Indiveri
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Arcavacata di Rende, Italy
| | - Rosita Accardi
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
| | - Massimo Tommasino
- International Agency for Research on Cancer (IARC), World Health Organization, Cours Albert Thomas, France
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Piazzi M, Bavelloni A, Faenza I, Blalock W. Glycogen synthase kinase (GSK)-3 and the double-strand RNA-dependent kinase, PKR: When two kinases for the common good turn bad. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1867:118769. [PMID: 32512016 PMCID: PMC7273171 DOI: 10.1016/j.bbamcr.2020.118769] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/29/2020] [Accepted: 05/31/2020] [Indexed: 01/08/2023]
Abstract
Glycogen synthase kinase (GSK)-3α/β and the double-stranded RNA-dependent kinase PKR are two sentinel kinases that carry-out multiple similar yet distinct functions in both the cytosol and the nucleus. While these kinases belong to separate signal transduction cascades, they demonstrate an uncanny propensity to regulate many of the same proteins either through direct phosphorylation or by altering transcription/translation, including: c-MYC, NF-κB, p53 and TAU, as well as each another. A significant number of studies centered on the GSK3 kinases have led to the identification of the GSK3 interactome and a number of substrates, which link GSK3 activity to metabolic control, translation, RNA splicing, ribosome biogenesis, cellular division, DNA repair and stress/inflammatory signaling. Interestingly, many of these same pathways and processes are controlled by PKR, but unlike the GSK3 kinases, a clear picture of proteins interacting with PKR and a complete listing of its substrates is still missing. In this review, we take a detailed look at what is known about the PKR and GSK3 kinases, how these kinases interact to influence common cellular processes (innate immunity, alternative splicing, translation, glucose metabolism) and how aberrant activation of these kinases leads to diseases such as Alzheimer's disease (AD), diabetes mellitus (DM) and cancer. GSK3α/β and PKR are major regulators of cellular homeostasis and the response to stress/inflammation and infection. GSK3α/β and PKR interact with and/or modify many of the same proteins and affect the expression of similar genes. A balance between AKT and PKR nuclear signaling may be responsible for regulating the activation of nuclear GSK3β. GSK3α/β- and PKR-dependent signaling influence major molecular mechanisms of the cell through similar intermediates. Aberrant activation of GSK3α/β and PKR is highly involved in cancer, metabolic disorders, and neurodegenerative diseases.
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Affiliation(s)
- Manuela Piazzi
- Istituto di Genetica Molecolare "Luigi Luca Cavalli-Sforza", Consiglio Nazionale delle Ricerche (IGM-CNR), Bologna, Italy; IRCCS, Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Alberto Bavelloni
- Laboratoria di Oncologia Sperimentale, IRCCS, Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Irene Faenza
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - William Blalock
- Istituto di Genetica Molecolare "Luigi Luca Cavalli-Sforza", Consiglio Nazionale delle Ricerche (IGM-CNR), Bologna, Italy; IRCCS, Istituto Ortopedico Rizzoli, Bologna, Italy.
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20
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Fujitani K, Otomo A, Nagayama Y, Tachibana T, Kato R, Kawashima Y, Kodera Y, Kato T, Takada S, Tamura K, Takamatsu N, Ito M. PACT/PRKRA and p53 regulate transcriptional activity of DMRT1. Genet Mol Biol 2020; 43:e20190017. [PMID: 32251494 PMCID: PMC7198010 DOI: 10.1590/1678-4685-gmb-2019-0017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 05/08/2019] [Indexed: 11/29/2022] Open
Abstract
The transcription factor DMRT1 (doublesex and mab-3 related transcription factor)
has two distinct functions, somatic-cell masculinization and germ-cell
development in some vertebrate species, including mouse and the African clawed
frog Xenopus laevis. However, its transcriptional regulation
remains unclear. We tried to identify DMRT1-interacting proteins from X.
laevis testes by immunoprecipitation with an anti-DMRT1 antibody
and MS/MS analysis, and selected three proteins, including PACT/PRKRA
(Interferon-inducible double-stranded RNA dependent protein kinase activator A)
derived from testes. Next, we examined the effects of PACT/PRKRA and/or p53 on
the transcriptional activity of DMRT1. In transfected 293T cells, PACT/PRKRA and
p53 significantly enhanced and repressed DMRT1-driven luciferase activity,
respectively. We also observed that the enhanced activity by PACT/PRKRA was
strongly attenuated by p53. Moreover, in situ hybridization
analysis of Pact/Prkra mRNA in tadpole gonads indicated high
expression in female and male germline stem cells. Taken together, these
findings suggest that PACT/PRKRA and p53 might positively and negatively
regulate the activity of DMRT1, respectively, for germline stem cell fate.
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Affiliation(s)
- Kazuko Fujitani
- Kitasato University, Gene Analysis Center, School of Medicine, Sagamihara, Japan
| | - Asako Otomo
- Tokai University School of Medicine, Department of Molecular Life Sciences, Isehara, Japan
| | - Yuto Nagayama
- Osaka City University, Department of Bioengineering, Graduate School of Engineering, Osaka, Japan
| | - Taro Tachibana
- Osaka City University, Department of Bioengineering, Graduate School of Engineering, Osaka, Japan.,Cell Engineering Corporation, Osaka, Japan
| | - Rika Kato
- Kitasato University, Department of Physics, School of Science, Sagamihara, Japan
| | - Yusuke Kawashima
- Kitasato University, Department of Physics, School of Science, Sagamihara, Japan
| | - Yoshio Kodera
- Kitasato University, Department of Physics, School of Science, Sagamihara, Japan
| | - Tomoko Kato
- National Research Institute for Child Health and Development, Department of Systems BioMedicine, Tokyo, Japan
| | - Shuji Takada
- National Research Institute for Child Health and Development, Department of Systems BioMedicine, Tokyo, Japan
| | - Kei Tamura
- Kitasato University, Department of Bioscience, School of Science, Sagamihara, Japan
| | - Nobuhiko Takamatsu
- Kitasato University, Department of Bioscience, School of Science, Sagamihara, Japan
| | - Michihiko Ito
- Kitasato University, Department of Bioscience, School of Science, Sagamihara, Japan
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21
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Wang C, Xu H, Lin S, Deng W, Zhou J, Zhang Y, Shi Y, Peng D, Xue Y. GPS 5.0: An Update on the Prediction of Kinase-specific Phosphorylation Sites in Proteins. GENOMICS PROTEOMICS & BIOINFORMATICS 2020; 18:72-80. [PMID: 32200042 PMCID: PMC7393560 DOI: 10.1016/j.gpb.2020.01.001] [Citation(s) in RCA: 152] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/18/2019] [Accepted: 02/26/2020] [Indexed: 02/07/2023]
Abstract
In eukaryotes, protein phosphorylation is specifically catalyzed by numerous protein kinases (PKs), faithfully orchestrates various biological processes, and reversibly determines cellular dynamics and plasticity. Here we report an updated algorithm of Group-based Prediction System (GPS) 5.0 to improve the performance for predicting kinase-specific phosphorylation sites (p-sites). Two novel methods, position weight determination (PWD) and scoring matrix optimization (SMO), were developed. Compared with other existing tools, GPS 5.0 exhibits a highly competitive accuracy. Besides serine/threonine or tyrosine kinases, GPS 5.0 also supports the prediction of dual-specificity kinase-specific p-sites. In the classical module of GPS 5.0, 617 individual predictors were constructed for predicting p-sites of 479 human PKs. To extend the application of GPS 5.0, a species-specific module was implemented to predict kinase-specific p-sites for 44,795 PKs in 161 eukaryotes. The online service and local packages of GPS 5.0 are freely available for academic research at http://gps.biocuckoo.cn.
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Affiliation(s)
- Chenwei Wang
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Haodong Xu
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Shaofeng Lin
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Wankun Deng
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Jiaqi Zhou
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ying Zhang
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Ying Shi
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Di Peng
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yu Xue
- (1)Key Laboratory of Molecular Biophysics of Ministry of Education, Hubei Bioinformatics and Molecular Imaging Key Laboratory, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China; (2)Huazhong University of Science and Technology Ezhou Industrial Technology Research Institute, Ezhou 436044, China.
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22
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Zharkov MI, Zenkova MA, Vlassov VV, Chernolovskaya EL. Molecular Mechanism of the Antiproliferative Activity of Short Immunostimulating dsRNA. Front Oncol 2020; 9:1454. [PMID: 31921696 PMCID: PMC6933605 DOI: 10.3389/fonc.2019.01454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 12/05/2019] [Indexed: 12/23/2022] Open
Abstract
Small double-stranded RNAs with certain sequence motifs are able to interact with pattern-recognition receptors and activate the innate immune system. Recently, we identified a set of short double-stranded 19-bp RNA molecules with 3-nucleotide 3′-overhangs that exhibited pronounced antiproliferative activity against cancer cells in vitro, and antitumor and antimetastatic activities in mouse models in vivo. The main objectives of this study were to identify the pattern recognition receptors that mediate the antiproliferative action of immunostimulating RNA (isRNA). Two cell lines, epidermoid carcinoma KB-3-1 cells and lung cancer A549 cells, were used in the study. These lines respond to the action of isRNA by a decrease in the growth rate, and in the case of A549 cells, also by a secretion of IL-6. Two sets of cell lines with selectively silenced genes encoding potential sensors and signal transducers of isRNA action were obtained on the basis of KB-3-1 and A549 cells. It was found that the selective silencing of PKR and RIG-I genes blocked the antiproliferative effect of isRNA, both in KB-3-1 and A549 cells, whereas the expression of MDA5 and IRF3 was not required for the antiproliferative action of isRNA. It was shown that, along with PKR and RIG-I genes, the expression of IRF3 also plays a role in isRNA mediated IL-6 synthesis in A549 cells. Thus, PKR and RIG-I sensors play a major role in the anti-proliferative signaling triggered by isRNA.
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Affiliation(s)
- Mikhail I Zharkov
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia
| | - Marina A Zenkova
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia
| | - Valentin V Vlassov
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia
| | - Elena L Chernolovskaya
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia
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23
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Piazzi M, Bavelloni A, Greco S, Focaccia E, Orsini A, Benini S, Gambarotti M, Faenza I, Blalock WL. Expression of the double-stranded RNA-dependent kinase PKR influences osteosarcoma attachment independent growth, migration, and invasion. J Cell Physiol 2019; 235:1103-1119. [PMID: 31240713 DOI: 10.1002/jcp.29024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 06/04/2019] [Indexed: 12/15/2022]
Abstract
Osteosarcoma (OS) is a rare, insidious tumor of mesenchymal origin that most often affects children, adolescents, and young adults. While the primary tumor can be controlled with chemotherapy and surgery, it is the lung metastases that are eventually fatal. Multiple studies into the initial drivers of OS development have been undertaken, but few of these have examined innate immune/inflammatory signaling. A central figure in inflammatory signaling is the innate immune/stress-activated kinase double-stranded RNA-dependent protein kinase (PKR). To characterize the role of PKR in OS, U2OS, and SaOS-2 osteosarcoma cell lines were stably transfected with wild-type or dominant-negative (DN) PKR. Overexpression of PKR enhanced colony formation in soft agar (U2OS and SaOS-2), enhanced cellular migration (U2OS), and invasive migration (SaOS-2). In contrast, overexpression of DN-PKR inhibited attachment-independent growth, migration and/or invasion. These data demonstrate a role for inflammatory signaling in OS formation and migration/invasion and suggest the status of PKR expression/activation may have prognostic value.
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Affiliation(s)
- Manuela Piazzi
- Istituto di Genetica Molecolare-Luigi Luca Cavalli Sforza, UOS Bologna, Consiglio Nazionale Delle Ricerche (IGM-CNR), Bologna, Italy.,IRCCS, Istituto Ortopedico Rizzoli, Bologna, Italy
| | | | - Sara Greco
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - Enrico Focaccia
- Istituto di Genetica Molecolare-Luigi Luca Cavalli Sforza, UOS Bologna, Consiglio Nazionale Delle Ricerche (IGM-CNR), Bologna, Italy
| | - Arianna Orsini
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | | | | | - Irene Faenza
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy
| | - William L Blalock
- Istituto di Genetica Molecolare-Luigi Luca Cavalli Sforza, UOS Bologna, Consiglio Nazionale Delle Ricerche (IGM-CNR), Bologna, Italy.,IRCCS, Istituto Ortopedico Rizzoli, Bologna, Italy
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24
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Lee YS, Kunkeaw N, Lee YS. Protein kinase R and its cellular regulators in cancer: An active player or a surveillant? WILEY INTERDISCIPLINARY REVIEWS-RNA 2019; 11:e1558. [PMID: 31231984 DOI: 10.1002/wrna.1558] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 05/24/2019] [Accepted: 05/28/2019] [Indexed: 12/12/2022]
Abstract
Protein kinase R (PKR), originally known as an antiviral protein, senses various stresses as well as pathogen-driven double-stranded RNAs. Thereby activated PKR provokes diverse downstream events, including eIF2α phosphorylation and nuclear factor kappa-light-chain-enhancer of activated B cells activation. Consequently, PKR induces apoptosis and inflammation, both of which are highly important in cancer as much as its original antiviral role. Therefore, cellular proteins and RNAs should tightly control PKR activity. PKR and its regulators are often dysregulated in cancer and it is undoubted that such dysregulation contributes to tumorigenesis. However, PKR's precise role in cancer is still in debate, due to incomprehensible and even contradictory data. In this review, we introduce important cellular PKR regulators and discuss about their roles in cancer. Among them, we pay particular attention to nc886, a PKR repressor noncoding RNA that has been identified relatively recently, because its expression pattern in cancer can explain interesting yet obscure oncologic aspects of PKR. Based on nc886 and its regulation of PKR, we have proposed a tumor surveillance model, which reconciles contradictory data about PKR in cancer. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Yong Sun Lee
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Korea
| | - Nawapol Kunkeaw
- Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
| | - Yeon-Su Lee
- Division of Clinical Research, Research Institute, National Cancer Center, Goyang, Korea
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25
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Gal-Ben-Ari S, Barrera I, Ehrlich M, Rosenblum K. PKR: A Kinase to Remember. Front Mol Neurosci 2019; 11:480. [PMID: 30686999 PMCID: PMC6333748 DOI: 10.3389/fnmol.2018.00480] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/10/2018] [Indexed: 12/26/2022] Open
Abstract
Aging is a major risk factor for many diseases including metabolic syndrome, cancer, inflammation, and neurodegeneration. Identifying mechanistic common denominators underlying the impact of aging is essential for our fundamental understanding of age-related diseases and the possibility to propose new ways to fight them. One can define aging biochemically as prolonged metabolic stress, the innate cellular and molecular programs responding to it, and the new stable or unstable state of equilibrium between the two. A candidate to play a role in the process is protein kinase R (PKR), first identified as a cellular protector against viral infection and today known as a major regulator of central cellular processes including mRNA translation, transcriptional control, regulation of apoptosis, and cell proliferation. Prolonged imbalance in PKR activation is both affected by biochemical and metabolic parameters and affects them in turn to create a feedforward loop. Here, we portray the central role of PKR in transferring metabolic information and regulating cellular function with a focus on cancer, inflammation, and brain function. Later, we integrate information from open data sources and discuss current knowledge and gaps in the literature about the signaling cascades upstream and downstream of PKR in different cell types and function. Finally, we summarize current major points and biological means to manipulate PKR expression and/or activation and propose PKR as a therapeutic target to shift age/metabolic-dependent undesired steady states.
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Affiliation(s)
- Shunit Gal-Ben-Ari
- Laboratory of Molecular and Cellular Mechanisms Underlying Learning and Memory, Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Iliana Barrera
- Laboratory of Molecular and Cellular Mechanisms Underlying Learning and Memory, Sagol Department of Neurobiology, University of Haifa, Haifa, Israel
| | - Marcelo Ehrlich
- Laboratory of Intracellular Trafficking and Signaling, School of Molecular Cell Biology & Biotechnology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Kobi Rosenblum
- Laboratory of Molecular and Cellular Mechanisms Underlying Learning and Memory, Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,Center for Gene Manipulation in the Brain, University of Haifa, Haifa, Israel
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26
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Wu L, He Y, Hu Y, Lu H, Cao Z, Yi X, Wang J. Real-time surface plasmon resonance monitoring of site-specific phosphorylation of p53 protein and its interaction with MDM2 protein. Analyst 2019; 144:6033-6040. [DOI: 10.1039/c9an01121h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Real-time monitoring of site-specific phosphorylation of p53 protein and its binding to MDM2 is conducted using dual-channel surface plasmon resonance (SPR).
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Affiliation(s)
- Ling Wu
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China 410083
| | - Yuhan He
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China 410083
| | - Yuqing Hu
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China 410083
| | - Hanwen Lu
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China 410083
| | - Zhong Cao
- Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation
- School of Chemistry and Biological Engineering
- Changsha University of Science and Technology
- Changsha
- P. R. China 410114
| | - Xinyao Yi
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China 410083
| | - Jianxiu Wang
- College of Chemistry and Chemical Engineering
- Central South University
- Changsha
- P. R. China 410083
- Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety
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27
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Garre S, Gamage AK, Faner TR, Dedigama-Arachchige P, Pflum MKH. Identification of Kinases and Interactors of p53 Using Kinase-Catalyzed Cross-Linking and Immunoprecipitation. J Am Chem Soc 2018; 140:16299-16310. [PMID: 30339384 DOI: 10.1021/jacs.8b10160] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Kinase enzymes phosphorylate protein substrates in a highly ordered manner to control cell signaling. Unregulated kinase activity is associated with a variety of disease states, most notably cancer, making the characterization of kinase activity in cells critical to understand disease formation. However, the paucity of available tools has prevented a full mapping of the substrates and interacting proteins of kinases involved in cellular function. Recently we developed kinase-catalyzed cross-linking to covalently connect substrate and kinase in a phosphorylation-dependent manner. Here, we report a new method combining kinase-catalyzed cross-linking and immunoprecipitation (K-CLIP) to identify kinase-substrate pairs and kinase-associated proteins. K-CLIP was applied to the substrate p53, which is robustly phosphorylated. Both known and unknown kinases of p53 were isolated from cell lysates using K-CLIP. In follow-up validation studies, MRCKbeta was identified as a new p53 kinase. Beyond kinases, a variety of p53 and kinase-associated proteins were also identified using K-CLIP, which provided a snapshot of cellular interactions. The K-CLIP method represents an immediately useful chemical tool to identify kinase-substrate pairs and multiprotein complexes in cells, which will embolden cell signaling research and enhance our understanding of kinase activity in normal and disease states.
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Affiliation(s)
- Satish Garre
- Department of Chemistry , Wayne State University , 5101 Cass Avenue , Detroit , Michigan 48202 , United States
| | - Aparni K Gamage
- Department of Chemistry , Wayne State University , 5101 Cass Avenue , Detroit , Michigan 48202 , United States
| | - Todd R Faner
- Department of Chemistry , Wayne State University , 5101 Cass Avenue , Detroit , Michigan 48202 , United States
| | | | - Mary Kay H Pflum
- Department of Chemistry , Wayne State University , 5101 Cass Avenue , Detroit , Michigan 48202 , United States
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28
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Zajkowicz A, Gdowicz-Kłosok A, Krześniak M, Janus P, Łasut B, Rusin M. The Alzheimer's disease-associated TREM2 gene is regulated by p53 tumor suppressor protein. Neurosci Lett 2018; 681:62-67. [PMID: 29842899 DOI: 10.1016/j.neulet.2018.05.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2018] [Revised: 05/24/2018] [Accepted: 05/25/2018] [Indexed: 11/27/2022]
Abstract
TREM2 mutations evoke neurodegenerative disorders, and recently genetic variants of this gene were correlated to increased risk of Alzheimer's disease. The signaling cascade originating from the TREM2 membrane receptor includes its binding partner TYROBP, BLNK adapter protein, and SYK kinase, which can be activated by p53. Moreover, in silico identification of a putative p53 response element (RE) at the TREM2 promoter led us to hypothesize that TREM2 and other pathway elements may be regulated in p53-dependent manner. To stimulate p53 in synergistic fashion, we exposed A549 lung cancer cells to actinomycin D and nutlin-3a (A + N). In these cells, exposure to A + N triggered expression of TREM2, TYROBP, SYK and BLNK in p53-dependent manner. TREM2 was also activated by A + N in U-2 OS osteosarcoma and A375 melanoma cell lines. Interestingly, nutlin-3a, a specific activator of p53, acting alone stimulated TREM2 in U-2 OS cells. Using in vitro mutagenesis, chromatin immunoprecipitation, and luciferase reporter assays, we confirmed the presence of the p53 RE in TREM2 promoter. Furthermore, activation of TREM2 and TYROBP by p53 was strongly inhibited by CHIR-98014, a potent and specific inhibitor of glycogen synthase kinase-3 (GSK-3). We conclude that TREM2 is a direct p53-target gene, and that activation of TREM2 by A + N or nutlin-3a may be critically dependent on GSK-3 function.
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Affiliation(s)
- Artur Zajkowicz
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute-Oncology Center, Gliwice Branch, 44-101 Gliwice, Poland
| | - Agnieszka Gdowicz-Kłosok
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute-Oncology Center, Gliwice Branch, 44-101 Gliwice, Poland
| | - Małgorzata Krześniak
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute-Oncology Center, Gliwice Branch, 44-101 Gliwice, Poland
| | - Patryk Janus
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute-Oncology Center, Gliwice Branch, 44-101 Gliwice, Poland
| | - Barbara Łasut
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute-Oncology Center, Gliwice Branch, 44-101 Gliwice, Poland
| | - Marek Rusin
- Center for Translational Research and Molecular Biology of Cancer, Maria Skłodowska-Curie Institute-Oncology Center, Gliwice Branch, 44-101 Gliwice, Poland.
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29
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Downregulation of PERK activity and eIF2α serine 51 phosphorylation by mTOR complex 1 elicits pro-oxidant and pro-death effects in tuberous sclerosis-deficient cells. Cell Death Dis 2018; 9:254. [PMID: 29449538 PMCID: PMC5833713 DOI: 10.1038/s41419-018-0326-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 01/12/2018] [Accepted: 01/18/2018] [Indexed: 12/11/2022]
Abstract
Oxidative stress determines cell fate through several mechanisms, among which regulation of mRNA translation by the phosphorylation of the alpha (α) subunit of the translation initiation factor eIF2α at serine 51 (eIF2αP) plays a prominent role. Increased eIF2αP can contribute to tumor progression as well as tumor suppression. While eIF2αP is increased in most cells to promote survival and adaptation to different forms of stress, we demonstrate that eIF2αP is reduced in tuberous sclerosis complex 2 (TSC2)-deficient cells subjected to oxidative insults. Decreased eIF2αP in TSC2-deficient cells depends on reactive oxygen species (ROS) production and is associated with a reduced activity of the endoplasmic reticulum (ER)-resident kinase PERK owing to the hyper-activation of the mammalian target of rapamycin complex 1 (mTORC1). Downregulation of PERK activity and eIF2αP is accompanied by increased ROS production and enhanced susceptibility of TSC2-deficient cells to extrinsic pro-oxidant stress. The decreased levels of eIF2αP delay tumor formation of TSC2-deficient cells in immune deficient mice, an effect that is significantly alleviated in mice subjected to an anti-oxidant diet. Our findings reveal a previously unidentified connection between mTORC1 and eIF2αP in TSC2-deficient cells with potential implications in tumor suppression in response to oxidative insults.
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30
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Serine 392 phosphorylation modulates p53 mitochondrial translocation and transcription-independent apoptosis. Cell Death Differ 2017; 25:190-203. [PMID: 28937686 DOI: 10.1038/cdd.2017.143] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 07/19/2017] [Accepted: 07/27/2017] [Indexed: 12/11/2022] Open
Abstract
The tumor suppressor p53 is a key regulator of apoptosis induced by various cellular stresses. p53 can induce apoptosis by two mechanisms. First, p53 acts as a transcription factor inducing and repressing pro-apoptotic and anti-apoptotic targets genes, respectively. Second, p53 is able to translocate to the mitochondria, where it interacts with BCL-2 family members to induce membrane permeabilization and cytochrome c release. p53 transcriptional activity is regulated by a set of post-translational modifications that have been well documented. However, how these modifications impact the direct mitochondrial pathway of death remain poorly understood. In this study, we focused on the role of serine 392 phosphorylation in the control of p53-dependent apoptosis. We used CRISPR/Cas9 genome editing to substitute serine 392 by a non-phosphorylatable alanine in HCT-116 colon carcinoma cells. The S392A mutant displayed normal transcriptional activity following genotoxic stress, but markedly impaired ability to localize to mitochondria. The decreased mitochondrial localization of the S392A mutant correlated with a lower ability to induce apoptosis. Confirmatory observations were made following enforced expression of the S392A p53 mutant or a phospho-mimetic S392E mutant in H1299 lung carcinoma cells. Our observations support the premise that serine 392 phosphorylation of p53 influences its mitochondrial translocation and transcription-independent apoptotic function.
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31
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Li X, Wu Z, An X, Mei Q, Bai M, Hanski L, Li X, Ahola T, Han W. Blockade of the LRP16-PKR-NF-κB signaling axis sensitizes colorectal carcinoma cells to DNA-damaging cytotoxic therapy. eLife 2017; 6:27301. [PMID: 28820388 PMCID: PMC5562444 DOI: 10.7554/elife.27301] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 07/17/2017] [Indexed: 12/12/2022] Open
Abstract
Acquired therapeutic resistance by tumors is a substantial impediment to reducing the morbidity and mortality that are attributable to human malignancies. The mechanisms responsible for the dramatic shift between chemosensitivity and chemoresistance in colorectal carcinoma have not been defined. Here, we report that LRP16 selectively interacts and activates double-stranded RNA-dependent kinase (PKR), and also acts as scaffolds to assist the formation of a ternary complex of PKR and IKKβ, prolonging the polymers of ADP-ribose (PAR)-dependent nuclear factor kappa B (NF-κB) transactivation caused by DNA-damaging agents and confers acquired chemoresistance. We also identified a small molecule, MRS2578, which strikingly abrogated the binding of LRP16 to PKR and IKKβ, converting LRP16 into a death molecule and forestalling colon tumorigenesis. Inclusion of MRS2578 with etoposide, versus each drug alone, exhibited synergistic antitumor cytotoxicity in xenografts. Our combinatorial approach introduces a strategy to enhance the efficacy of genotoxicity therapies for the treatment of tumors.
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Affiliation(s)
- Xiaolei Li
- Department of Molecular Biology, Immunological and Bio-therapeutic, Institute of Basic Medicine, Chinese PLA General Hospital, Beijing, China
| | - Zhiqiang Wu
- Department of Molecular Biology, Immunological and Bio-therapeutic, Institute of Basic Medicine, Chinese PLA General Hospital, Beijing, China
| | - Xiaojing An
- Department of Pathology, Chinese PLA General Hospital, Beijing, China.,Department of Pathology, Xiyuan Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Qian Mei
- Department of Molecular Biology, Immunological and Bio-therapeutic, Institute of Basic Medicine, Chinese PLA General Hospital, Beijing, China
| | - Miaomiao Bai
- Department of Molecular Biology, Immunological and Bio-therapeutic, Institute of Basic Medicine, Chinese PLA General Hospital, Beijing, China
| | - Leena Hanski
- Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Xiang Li
- Department of Molecular Biology, Immunological and Bio-therapeutic, Institute of Basic Medicine, Chinese PLA General Hospital, Beijing, China
| | - Tero Ahola
- Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Weidong Han
- Department of Molecular Biology, Immunological and Bio-therapeutic, Institute of Basic Medicine, Chinese PLA General Hospital, Beijing, China
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Clinical and therapeutic potential of protein kinase PKR in cancer and metabolism. Expert Rev Mol Med 2017; 19:e9. [PMID: 28724458 DOI: 10.1017/erm.2017.11] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The protein kinase R (PKR, also called EIF2AK2) is an interferon-inducible double-stranded RNA protein kinase with multiple effects on cells that plays an active part in the cellular response to numerous types of stress. PKR has been extensively studied and documented for its relevance as an antiviral agent and a cell growth regulator. Recently, the role of PKR related to metabolism, inflammatory processes, cancer and neurodegenerative diseases has gained interest. In this review, we summarise and discuss the involvement of PKR in several cancer signalling pathways and the dual role that this kinase plays in cancer disease. We emphasise the importance of PKR as a molecular target for both conventional chemotherapeutics and emerging treatments based on novel drugs, and its potential as a biomarker and therapeutic target for several pathologies. Finally, we discuss the impact that the recent knowledge regarding PKR involvement in metabolism has in our understanding of the complex processes of cancer and metabolism pathologies, highlighting the translational research establishing the clinical and therapeutic potential of this pleiotropic kinase.
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Maluchenko NV, Chang HW, Kozinova MT, Valieva ME, Gerasimova NS, Kitashov AV, Kirpichnikov MP, Georgiev PG, Studitsky VM. Inhibiting the pro-tumor and transcription factor FACT: Mechanisms. Mol Biol 2016. [DOI: 10.1134/s0026893316040087] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Itoh Y, Murata A, Sakamoto S, Nanatani K, Wada T, Takahashi S, Kamagata K. Activation of p53 Facilitates the Target Search in DNA by Enhancing the Target Recognition Probability. J Mol Biol 2016; 428:2916-30. [DOI: 10.1016/j.jmb.2016.06.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 05/23/2016] [Accepted: 06/02/2016] [Indexed: 12/11/2022]
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Song Y, Wan X, Gao L, Pan Y, Xie W, Wang H, Guo J. Activated PKR inhibits pancreatic β-cell proliferation through sumoylation-dependent stabilization of P53. Mol Immunol 2015; 68:341-9. [PMID: 26446704 DOI: 10.1016/j.molimm.2015.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 08/27/2015] [Accepted: 09/02/2015] [Indexed: 12/20/2022]
Abstract
Double-stranded RNA-dependent protein kinase (PKR) is intimately involved in type 2 diabetes due to its role in insulin resistance in peripheral tissues and anti-proliferative effect on pancreatic β-cells. Activated PKR was found to inhibit β-cell proliferation, partially through accumulation of P53. However the molecular mechanisms underlying PKR-dependent upregulation of P53 remain unknown. The results of the present study showed that PKR can be specifically activated in PKR overexpressing β-cells by a low dosage of the previously synthesized compound 1H-benzimidazole1-ethanol,2,3-dihydro-2-imino-a-(phenoxymethyl)-3-(phenylmethyl)-,monohydrochloride (BEPP), and this led to upregulation of P53 through sumoylation-dependent stability. Activated PKR was found to interact with sumo-conjugating enzyme Ubc9, and P53 sumoylation relies on a PKR-Ubc9 protein-protein interaction. Additionally, a ceramide signal was needed for PKR activation to be triggered by glucolipotoxicity and TNFα stimulation, and stabilization of P53 required endogenous ceramide accumulation. Glucolipotoxicity and pro-inflammatory cytokines therefore promote the sumoylation-dependent stability of P53 via the ceramide/PKR/Ubc9 signalling pathway that is involved in pancreatic β-cell proliferation inhibition in the development of type 2 diabetes.
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Affiliation(s)
- Ying Song
- Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, PR China
| | - XiaoMeng Wan
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, PR China
| | - LiLi Gao
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, PR China
| | - Yi Pan
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, PR China
| | - WeiPing Xie
- Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, PR China
| | - Hong Wang
- Department of Respiratory Medicine, The First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, PR China.
| | - Jun Guo
- Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing 210029, PR China
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PKR inhibits the DNA damage response, and is associated with poor survival in AML and accelerated leukemia in NHD13 mice. Blood 2015. [PMID: 26202421 DOI: 10.1182/blood-2015-03-635227] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Increased expression of the interferon-inducible double-stranded RNA-activated protein kinase (PKR) has been reported in acute leukemia and solid tumors, but the role of PKR has been unclear. Now, our results indicate that high PKR expression in CD34(+) cells of acute myeloid leukemia (AML) patients correlates with worse survival and shortened remission duration. Significantly, we find that PKR has a novel and previously unrecognized nuclear function to inhibit DNA damage response signaling and double-strand break repair. Nuclear PKR antagonizes ataxia-telangiectasia mutated (ATM) activation by a mechanism dependent on protein phosphatase 2A activity. Thus, inhibition of PKR expression or activity promotes ATM activation, γ-H2AX formation, and phosphorylation of NBS1 following ionizing irradiation. PKR transgenic but not PKR null mice demonstrate a mutator phenotype characterized by radiation-induced and age-associated genomic instability that was partially reversed by short-term pharmacologic PKR inhibition. Furthermore, the age-associated accumulation of somatic mutations that occurs in the Nup98-HOXD13 (NHD13) mouse model of leukemia progression was significantly elevated by co-expression of a PKR transgene, whereas knockout of PKR expression or pharmacologic inhibition of PKR activity reduced the frequency of spontaneous mutations in vivo. Thus, PKR cooperated with the NHD13 transgene to accelerate leukemia progression and shorten survival. Taken together, these results indicate that increased nuclear PKR has an oncogenic function that promotes the accumulation of potentially deleterious mutations. Thus, PKR inhibition may be a therapeutically useful strategy to prevent leukemia progression or relapse, and improve clinical outcomes.
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Koromilas AE. Roles of the translation initiation factor eIF2α serine 51 phosphorylation in cancer formation and treatment. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:871-80. [PMID: 25497381 DOI: 10.1016/j.bbagrm.2014.12.007] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/03/2014] [Accepted: 12/07/2014] [Indexed: 01/12/2023]
Abstract
Cells respond to various forms of stress by activating anti-proliferative pathways, which allow them to correct the damage caused by stress before re-entering proliferation. If the damage, however, is beyond repair, stressed cells are eliminated from the host by undergoing death. The balance between cell survival and death is essential for cancer formation and is determined by several key pathways that impact on different stages of gene expression. In recent years, it has become evident that phosphorylation of the alpha (α) subunit of the translation initiation factor eIF2 at serine 51 (eIF2αS51P) is an important determinant of cell fate in response to stress. Induction of eIF2αS51P is mediated by a family of four kinases namely, HRI, PKR, PERK and GCN2, each of which responds to distinct forms of stress. Increased eIF2αS51P results in a global inhibition of protein synthesis but at the same time enhances the translation of select mRNAs encoding for proteins that control cell adaptation to stress. Short-term induction of eIF2αS51P has been associated with cell survival whereas long-term induction with cell death. Studies in mouse and human models of cancer have provided compelling evidence that eIF2αS51P plays an essential role in stress-induced tumorigenesis. Increased eIF2αS51P exhibits cell autonomous as well as immune regulatory effects, which can influence tumor growth and the efficacy of anti-tumor therapies. The findings suggest that eIF2αS51P may be of prognostic value and a suitable target for the design and implementation of effective anti-tumor therapies. This article is part of a Special Issue entitled: Translation and Cancer.
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Affiliation(s)
- Antonis E Koromilas
- Lady Davis Institute for Medical Research-McGill University, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada; Department of Oncology, Faculty of Medicine, McGill University, Montreal, Quebec H2W 1S6, Canada.
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Zhang S, Sun Y, Chen H, Dai Y, Zhan Y, Yu S, Qiu X, Tan L, Song C, Ding C. Activation of the PKR/eIF2α signaling cascade inhibits replication of Newcastle disease virus. Virol J 2014; 11:62. [PMID: 24684861 PMCID: PMC3994276 DOI: 10.1186/1743-422x-11-62] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 03/27/2014] [Indexed: 12/15/2022] Open
Abstract
Background Newcastle Disease virus (NDV) causes severe and economically significant disease in almost all birds. However, factors that affect NDV replication in host cells are poorly understood. NDV generates long double-stranded RNA (dsRNA) molecules during transcription of single-stranded genomic RNA. Protein kinase R (PKR) is activated by dsRNA. The aim of this study was to elucidate the role of PKR in NDV infection. Results NDV infection led to the activation of dsRNA-dependent PKR and phosphorylation of its substrate, translation initiation factor eIF2α, in a dose-dependent manner by either the lentogenic strain LaSota or a velogenic strain Herts/33. PKR activation coincided with the accumulation of dsRNA induced by NDV infection. PKR knockdown remarkably decreased eIF2α phosphorylation as well as IFN-β mRNA levels, leading to the augmentation of extracellular virus titer. Furthermore, siRNA knockdown or phosphorylation of eIF2α or okadaic acid treatment significantly impaired NDV replication, indicating the critical role of the PKR/eIF2α signaling cascade in NDV infection. Conclusion PKR is activated by dsRNA generated by NDV infection and inhibits NDV replication by eIF2α phosphorylation. This study provides insight into NDV-host interactions for the development of candidate antiviral strategies.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No,518 Ziyue Road, Shanghai 200241, China.
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Marchal JA, Lopez GJ, Peran M, Comino A, Delgado JR, García-García JA, Conde V, Aranda FM, Rivas C, Esteban M, Garcia MA. The impact of PKR activation: from neurodegeneration to cancer. FASEB J 2014; 28:1965-74. [PMID: 24522206 DOI: 10.1096/fj.13-248294] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
An inverse association between cancer and neurodegeneration is plausible because these biological processes share several genes and signaling pathways. Whereas uncontrolled cell proliferation and decreased apoptotic cell death governs cancer, excessive apoptosis contributes to neurodegeneration. Protein kinase R (PKR), an interferon-inducible double-stranded RNA protein kinase, is involved in both diseases. PKR activation blocks global protein synthesis through eIF2α phosphorylation, leading to cell death in response to a variety of cellular stresses. However, PKR also has the dual role of activating the nuclear factor κ-B pathway, promoting cell proliferation. Whereas PKR is recognized for its negative effects on neurodegenerative diseases, in part, inducing high level of apoptosis, the role of PKR activation in cancer remains controversial. In general, PKR is considered to have a tumor suppressor function, and some clinical data show a correlation between suppressed or inactivated PKR and a poor prognosis for several cancers. However, other studies show high PKR expression and activation levels in various cancers, suggesting that PKR might contribute to neoplastic progression. Understanding the cellular factors and signals involved in the regulation of PKR in these age-related diseases is relevant and may have important clinical implications. The present review highlights the current knowledge on the role of PKR in neurodegeneration and cancer, with special emphasis on its regulation and clinical implications.
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Affiliation(s)
- Juan A Marchal
- 1University Hospital Virgen de las Nieves, Azpitarte sn., Granada E-18012, Spain.
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Koromilas AE, Mounir Z. Control of oncogenesis by eIF2α phosphorylation: implications in PTEN and PI3K-Akt signaling and tumor treatment. Future Oncol 2014; 9:1005-15. [PMID: 23837763 DOI: 10.2217/fon.13.49] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
mRNA translation plays an important role in tumor development and represents a valid target of pharmaceutical intervention in cancer. A key step in mRNA translation involves the regulation of initiation by the eukaryotic initiation factor eIF2. Eukaryotic cells respond to various forms of stress by inducing the phosphorylation of the α-subunit of eIF2 at S51, a modification that leads to protein synthesis inhibition. Phosphorylated eIF2α can act either as a promoter of cell survival or an inducer of cell death in response to distinct stimuli. Increased eIF2α phosphorylation has a cytoprotective function in response to genetic or pharmacological inhibition of the PI3K-Akt pathway but also exhibits a proapoptotic function downstream of the PTEN tumor suppressor, independent of PI3K-Akt signaling inhibition. The functional interplay between the PI3K-Akt and eIF2α phosphorylation pathways may have important implications in the design of anti-tumor therapies that depend on the cell fate decisions of phosphorylated eIF2α.
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Transcriptional activation of p21(WAF¹/CIP¹) is mediated by increased DNA binding activity and increased interaction between p53 and Sp1 via phosphorylation during replicative senescence of human embryonic fibroblasts. Mol Biol Rep 2014; 41:2397-408. [PMID: 24445528 DOI: 10.1007/s11033-014-3094-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 01/04/2014] [Indexed: 12/11/2022]
Abstract
Although p21(WAF1/CIP1) is known to be elevated during replicative senescence of human embryonic fibroblasts (HEFs), the mechanism for p21 up-regulation has not been elucidated clearly. In order to explore the mechanism, we analyzed expression of p21 mRNA and protein and luciferase activity of full-length p21 promoter. The result demonstrated that p21 up-regulation was accomplished largely at transcription level. The promoter assay using serially-deleted p21 promoter constructs revealed that p53 binding site was the most important site and Sp1 binding sites were necessary but not sufficient for transcriptional activation of p21. In addition, p53 protein was shown to interact with Sp1 protein. The interaction was increased in aged fibroblasts and was regulated by phosphorylation of p53 and Sp1. DNA binding activity of p53 was significantly elevated in aged fibroblasts but that of Sp1 was not. DNA binding activities of p53 and Sp1 were also regulated by phosphorylation. Phosphorylation of p53 at serine-15 and of Sp1 at serines appears to be involved. Taken together, the result demonstrated that p21 transcription during replicative senescence of HEFs is up-regulated by increase in DNA binding activity and interaction between p53 and Sp1 via phosphorylation.
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42
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Barra NG, Gillgrass A, Ashkar AA. Effective control of viral infections by the adaptive immune system requires assistance from innate immunity. Expert Rev Vaccines 2014; 9:1143-7. [DOI: 10.1586/erv.10.119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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43
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Goossens KE, Ward AC, Lowenthal JW, Bean AGD. Chicken interferons, their receptors and interferon-stimulated genes. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2013; 41:370-376. [PMID: 23751330 DOI: 10.1016/j.dci.2013.05.020] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 05/31/2013] [Accepted: 05/31/2013] [Indexed: 06/02/2023]
Abstract
The prevalence of pathogenic viruses is a serious issue as they pose a constant threat to both the poultry industry and to human health. To prevent these viral infections an understanding of the host-virus response is critical, especially for the development of novel therapeutics. One approach in the control of viral infections would be to boost the immune response through administration of cytokines, such as interferons. However, the innate immune response in chickens is poorly characterised, particularly concerning the interferon pathway. This review will provide an overview of our current understanding of the interferon system of chickens, including their cognate receptors and known interferon-stimulated gene products.
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Affiliation(s)
- Kate E Goossens
- CSIRO Biosecurity Flagship, Australian Animal Health Laboratories, Geelong, VIC, Australia
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Donnelly N, Gorman AM, Gupta S, Samali A. The eIF2α kinases: their structures and functions. Cell Mol Life Sci 2013; 70:3493-511. [PMID: 23354059 PMCID: PMC11113696 DOI: 10.1007/s00018-012-1252-6] [Citation(s) in RCA: 587] [Impact Index Per Article: 53.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2012] [Revised: 12/16/2012] [Accepted: 12/20/2012] [Indexed: 01/02/2023]
Abstract
Cell signaling in response to an array of diverse stress stimuli converges on the phosphorylation of the α-subunit of eukaryotic initiation factor 2 (eIF2). Phosphorylation of eIF2α on serine 51 results in a severe decline in de novo protein synthesis and is an important strategy in the cell's armory against stressful insults including viral infection, the accumulation of misfolded proteins, and starvation. The phosphorylation of eIF2α is carried out by a family of four kinases, PERK (PKR-like ER kinase), PKR (protein kinase double-stranded RNA-dependent), GCN2 (general control non-derepressible-2), and HRI (heme-regulated inhibitor). Each primarily responds to a distinct type of stress or stresses. Thus, while significant sequence similarity exists between the eIF2α kinases in their kinase domains, underlying their common role in phosphorylating eIF2α, additional unique features determine the regulation of these four proteins, that is, what signals activate them. This review will describe the structure of each eIF2α kinase and discuss how this is linked to their activation and function. In parallel to the general translational attenuation elicited by eIF2α kinase activation the translation of stress-induced mRNAs, most notably activating transcription factor 4 (ATF4) is enhanced and these set in motion cascades of gene expression constituting the integrated stress response (ISR), which seek to remediate stress and restore homeostasis. Depending on the cellular context and concurrent signaling pathways active, however, translational attenuation can also facilitate apoptosis. Accordingly, the role of the kinases in determining cell fate will also be discussed.
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Affiliation(s)
- Neysan Donnelly
- Apoptosis Research Center, National University of Ireland, Galway, Ireland
- School of Natural Sciences, National University of Ireland, Galway, Ireland
- Present Address: Department of Molecular Cell Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, Martinsried, Munich, 82152 Germany
| | - Adrienne M. Gorman
- Apoptosis Research Center, National University of Ireland, Galway, Ireland
- School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Sanjeev Gupta
- Apoptosis Research Center, National University of Ireland, Galway, Ireland
- School of Medicine, National University of Ireland, Galway, Ireland
| | - Afshin Samali
- Apoptosis Research Center, National University of Ireland, Galway, Ireland
- School of Natural Sciences, National University of Ireland, Galway, Ireland
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Lu Y, Xu D, Zhou J, Ma Y, Jiang Y, Zeng W, Dai W. Differential responses to genotoxic agents between induced pluripotent stem cells and tumor cell lines. J Hematol Oncol 2013; 6:71. [PMID: 24283650 PMCID: PMC3856456 DOI: 10.1186/1756-8722-6-71] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 09/09/2013] [Indexed: 12/14/2022] Open
Abstract
Given potential values of induced pluripotent stem (iPS) cells in basic biomedical research and regenerative medicine, it is important to understand how these cells regulate their genome stability in response to environmental toxins and carcinogens. The present study characterized the effect of Cr(VI), a well-known genotoxic agent and environmental carcinogen, on major molecular components of DNA damage response pathways in human iPS cells. We compared the effect of Cr(VI) on human iPS cells with two established cell lines, Tera-1 (teratoma origin) and BEAS-2B (lung epithelial origin). We also studied the effect of hydrogen peroxide and doxorubicin on modulating DNA damage responses in these cell types. We demonstrated that ATM and p53 phosphorylation is differentially regulated in human iPS cells compared with Tera-1 and BEAS-2B cells after exposure to various genotoxic agents. Moreover, we observed that inhibition of CK2, but not p38, promotes phosphorylation of p53S392 in iPS cells. Combined, our data reveal some unique features of DNA damage responses in human iPS cells.
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Affiliation(s)
| | | | | | | | | | - Wenxian Zeng
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
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46
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Sharon D, Schümann M, MacLeod S, McPherson R, Chaurasiya S, Shaw A, Hitt MM. 2-aminopurine enhances the oncolytic activity of an E1b-deleted adenovirus in hepatocellular carcinoma cells. PLoS One 2013; 8:e65222. [PMID: 23750246 PMCID: PMC3672087 DOI: 10.1371/journal.pone.0065222] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 04/23/2013] [Indexed: 01/01/2023] Open
Abstract
Adenoviruses with deletions of viral genes have been extensively studied as potential cancer therapeutics. Although a high degree of cancer selectivity has been demonstrated with these conditionally replicating adenoviruses, low levels of virus replication can be detected in normal cells. Furthermore, these mutations were also found to reduce the activity of the replicating viruses in certain cancer cells. Recent studies have shown that co-administration of chemotherapeutic drugs may increase the activity of these viruses without affecting their specificity. We constructed an adenovirus with deletions of both the E1b and the VA-RNA genes and found that replication of this virus was selective for human hepatocellular carcinoma (HCC) cell lines when compared to normal cell lines. Furthermore, we show that 2-aminopurine (2′AP) treatment selectively enhanced virus replication and virus-mediated death of HCC cells. 2′AP did not compensate for the loss of VA-RNA activities, but rather the loss of an E1b-55K activity, such as the DNA damage response, suggesting that co-administration of 2′AP derivatives that block host DNA damage response, may increase the oncolytic activity of AdΔE1bΔVA without reducing its selectivity for HCC cells.
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Affiliation(s)
- David Sharon
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Michael Schümann
- Institut für Virologie, Klinikum der Philipps-Universität Marburg, Marburg, Germany
| | - Sheena MacLeod
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Robyn McPherson
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | | | - Andrew Shaw
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Mary M. Hitt
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
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Abstract
The double-stranded RNA-dependent protein kinase PKR plays multiple roles in cells, in response to different stress situations. As a member of the interferon (IFN)‑Stimulated Genes, PKR was initially recognized as an actor in the antiviral action of IFN, due to its ability to control translation, through phosphorylation, of the alpha subunit of eukaryotic initiation factor 2 (eIF2α). As such, PKR participates in the generation of stress granules, or autophagy and a number of viruses have designed strategies to inhibit its action. However, PKR deficient mice resist most viral infections, indicating that PKR may play other roles in the cell other than just acting as an antiviral agent. Indeed, PKR regulates several signaling pathways, either as an adapter protein and/or using its kinase activity. Here we review the role of PKR as an eIF2α kinase, its participation in the regulation of the NF-κB, p38MAPK and insulin pathways, and we focus on its role during infection with the hepatitis C virus (HCV). PKR binds the HCV IRES RNA, cooperates with some functions of the HCV core protein and may represent a target for NS5A or E2. Novel data points out for a role of PKR as a pro-HCV agent, both as an adapter protein and as an eIF2α-kinase, and in cooperation with the di-ubiquitin-like protein ISG15. Developing pharmaceutical inhibitors of PKR may help in resolving some viral infections as well as stress-related damages.
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Affiliation(s)
- Stéphanie Dabo
- Unit Hepacivirus and Innate Immunity, Department Virology, Institut Pasteur, 28 rue du Dr Roux, 75724 Paris Cedex 15, France.
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The infectious bursal disease virus RNA-binding VP3 polypeptide inhibits PKR-mediated apoptosis. PLoS One 2012; 7:e46768. [PMID: 23056444 PMCID: PMC3467284 DOI: 10.1371/journal.pone.0046768] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 09/05/2012] [Indexed: 01/07/2023] Open
Abstract
Infectious bursal disease virus (IBDV) is an avian pathogen responsible for an acute immunosuppressive disease that causes major losses to the poultry industry. Despite having a bipartite dsRNA genome, IBDV, as well as other members of the Birnaviridae family, possesses a single capsid layer formed by trimers of the VP2 capsid protein. The capsid encloses a ribonucleoprotein complex formed by the genome associated to the RNA-dependent RNA polymerase and the RNA-binding polypeptide VP3. A previous report evidenced that expression of the mature VP2 IBDV capsid polypeptide triggers a swift programmed cell death response in a wide variety of cell lines. The mechanism(s) underlying this effect remained unknown. Here, we show that VP2 expression in HeLa cells activates the double-stranded RNA (dsRNA)-dependent protein kinase (PKR), which in turn triggers the phosphorylation of the eukaryotic initiation factor 2α (eIF2α). This results in a strong blockade of protein synthesis and the activation of an apoptotic response which is efficiently blocked by coexpression of a dominant negative PKR polypeptide. Our results demonstrate that coexpression of the VP3 polypeptide precludes phosphorylation of both PKR and eIF2α and the onset of programmed cell death induced by VP2 expression. A mutation blocking the capacity of VP3 to bind dsRNA also abolishes its capacity to prevent PKR activation and apoptosis. Further experiments showed that VP3 functionally replaces the host-range vaccinia virus (VACV) E3 protein, thus allowing the E3 deficient VACV deletion mutant WRΔE3L to grow in non-permissive cell lines. According to results presented here, VP3 can be categorized along with other well characterized proteins such us VACV E3, avian reovirus sigmaA, and influenza virus NS1 as a virus-encoded dsRNA-binding polypeptide with antiapoptotic properties. Our results suggest that VP3 plays a central role in ensuring the viability of the IBDV replication cycle by preventing programmed cell death.
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Increased expression of the dsRNA-activated protein kinase PKR in breast cancer promotes sensitivity to doxorubicin. PLoS One 2012; 7:e46040. [PMID: 23029376 PMCID: PMC3454339 DOI: 10.1371/journal.pone.0046040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/28/2012] [Indexed: 11/19/2022] Open
Abstract
It has been reported that the expression and activity of the interferon-inducible, dsRNA-dependent protein kinase, PKR, is increased in mammary carcinoma cell lines and primary tumor samples. To extend these findings and determine how PKR signaling may affect breast cancer cell sensitivity to chemotherapy, we measured PKR expression by immunohistochemical staining of 538 cases of primary breast cancer and normal tissues. Significantly, PKR expression was elevated in ductal, lobular and squamous cell carcinomas or lymph node metastases but not in either benign tumor specimens or cases of inflammation compared to normal tissues. Furthermore, PKR expression was increased in precancerous stages of mammary cell hyperplasia and dysplasia compared to normal tissues, indicating that PKR expression may be upregulated by the process of tumorigenesis. To test the function of PKR in breast cancer, we generated MCF7, T-47D and MDA-MB-231 breast cancer cell lines with significantly reduced PKR expression by siRNA knockdown. Importantly, while knockdown of PKR expression had no effect on cell proliferation under normal growth conditions, MCF7, T-47D or MDA-MB-231 cells with reduced PKR expression or treated with a small molecule PKR inhibitor were significantly less sensitive to doxorubicin or H2O2-induced toxicity compared to control cells. In addition, the rate of eIF2α phosphorylation following treatment with doxorubicin was delayed in breast cancer cell lines with decreased PKR expression. Significantly, treatment of breast cancer lines with reduced PKR expression with either interferon-α, which increases PKR expression, or salubrinal, which increases eIF2α phosphorylation, restored doxorubicin sensitivity to normal levels. Taken together these results indicate that increased PKR expression in primary breast cancer tissues may serve as a biomarker for response to doxorubicin-containing chemotherapy and that future therapeutic approaches to promote PKR expression/activation and eIF2α phosphorylation may be beneficial for the treatment of breast cancer.
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Gasparian AV, Burkhart CA, Purmal AA, Brodsky L, Pal M, Saranadasa M, Bosykh DA, Commane M, Guryanova OA, Pal S, Safina A, Sviridov S, Koman IE, Veith J, Komar AA, Gudkov AV, Gurova KV. Curaxins: anticancer compounds that simultaneously suppress NF-κB and activate p53 by targeting FACT. Sci Transl Med 2012; 3:95ra74. [PMID: 21832239 DOI: 10.1126/scitranslmed.3002530] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Effective eradication of cancer requires treatment directed against multiple targets. The p53 and nuclear factor κB (NF-κB) pathways are dysregulated in nearly all tumors, making them attractive targets for therapeutic activation and inhibition, respectively. We have isolated and structurally optimized small molecules, curaxins, that simultaneously activate p53 and inhibit NF-κB without causing detectable genotoxicity. Curaxins demonstrated anticancer activity against all tested human tumor xenografts grown in mice. We report here that the effects of curaxins on p53 and NF-κB, as well as their toxicity to cancer cells, result from "chromatin trapping" of the FACT (facilitates chromatin transcription) complex. This FACT inaccessibility leads to phosphorylation of the p53 Ser(392) by casein kinase 2 and inhibition of NF-κB-dependent transcription, which requires FACT activity at the elongation stage. These results identify FACT as a prospective anticancer target enabling simultaneous modulation of several pathways frequently dysregulated in cancer without induction of DNA damage. Curaxins have the potential to be developed into effective and safe anticancer drugs.
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