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Hudler P, Urbancic M. The Role of VHL in the Development of von Hippel-Lindau Disease and Erythrocytosis. Genes (Basel) 2022; 13:genes13020362. [PMID: 35205407 PMCID: PMC8871608 DOI: 10.3390/genes13020362] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/14/2022] [Accepted: 02/15/2022] [Indexed: 12/20/2022] Open
Abstract
Von Hippel-Lindau disease (VHL disease or VHL syndrome) is a familial multisystem neoplastic syndrome stemming from germline disease-associated variants of the VHL tumor suppressor gene on chromosome 3. VHL is involved, through the EPO-VHL-HIF signaling axis, in oxygen sensing and adaptive response to hypoxia, as well as in numerous HIF-independent pathways. The diverse roles of VHL confirm its implication in several crucial cellular processes. VHL variations have been associated with the development of VHL disease and erythrocytosis. The association between genotypes and phenotypes still remains ambiguous for the majority of mutations. It appears that there is a distinction between erythrocytosis-causing VHL variations and VHL variations causing VHL disease with tumor development. Understanding the pathogenic effects of VHL variants might better predict the prognosis and optimize management of the patient.
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Affiliation(s)
- Petra Hudler
- Medical Centre for Molecular Biology, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Vrazov trg 2, 1000 Ljubljana, Slovenia;
| | - Mojca Urbancic
- Eye Hospital, University Medical Centre Ljubljana, Grabloviceva ulica 46, 1000 Ljubljana, Slovenia
- Correspondence:
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2
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Chellappan R, Guha A, Si Y, Kwan T, Nabors LB, Filippova N, Yang X, Myneni AS, Meesala S, Harms AS, King PH. SRI-42127, a novel small molecule inhibitor of the RNA regulator HuR, potently attenuates glial activation in a model of lipopolysaccharide-induced neuroinflammation. Glia 2022; 70:155-172. [PMID: 34533864 PMCID: PMC8595840 DOI: 10.1002/glia.24094] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/03/2021] [Accepted: 09/06/2021] [Indexed: 01/03/2023]
Abstract
Glial activation with the production of pro-inflammatory mediators is a major driver of disease progression in neurological processes ranging from acute traumatic injury to chronic neurodegenerative diseases such as amyotrophic lateral sclerosis and Alzheimer's disease. Posttranscriptional regulation is a major gateway for glial activation as many mRNAs encoding pro-inflammatory mediators contain adenine- and uridine-rich elements (ARE) in the 3' untranslated region which govern their expression. We have previously shown that HuR, an RNA regulator that binds to AREs, plays a major positive role in regulating inflammatory cytokine production in glia. HuR is predominantly nuclear in localization but translocates to the cytoplasm to exert a positive regulatory effect on RNA stability and translational efficiency. Homodimerization of HuR is necessary for translocation and we have developed a small molecule inhibitor, SRI-42127, that blocks this process. Here we show that SRI-42127 suppressed HuR translocation in LPS-activated glia in vitro and in vivo and significantly attenuated the production of pro-inflammatory mediators including IL1β, IL-6, TNF-α, iNOS, CXCL1, and CCL2. Cytokines typically associated with anti-inflammatory effects including TGF-β1, IL-10, YM1, and Arg1 were either unaffected or minimally affected. SRI-42127 suppressed microglial activation in vivo and attenuated the recruitment/chemotaxis of neutrophils and monocytes. RNA kinetic studies and luciferase studies indicated that SRI-42127 has inhibitory effects both on mRNA stability and gene promoter activation. In summary, our findings underscore HuR's critical role in promoting glial activation and the potential for SRI-42127 and other HuR inhibitors for treating neurological diseases driven by this activation.
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Affiliation(s)
- Rajeshwari Chellappan
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294,,Birmingham Veterans Affairs Medical Center, Birmingham, AL 35294
| | - Abhishek Guha
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Ying Si
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294,,Birmingham Veterans Affairs Medical Center, Birmingham, AL 35294
| | - Thaddaeus Kwan
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - L. Burt Nabors
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Natalia Filippova
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Xiuhua Yang
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Anish S. Myneni
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Shriya Meesala
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Ashley S Harms
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Peter H. King
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294,,Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294,,Birmingham Veterans Affairs Medical Center, Birmingham, AL 35294,Correspondence to: Dr. P.H. King; UAB Dept. of Neurology, Civitan 545C, 1530 3 Avenue South, Birmingham, AL 35294-0017, USA. Tel. (205) 975-8116; Fax (205) 996-7255;
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3
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Janecki DM, Swiatkowska A, Szpotkowska J, Urbanowicz A, Kabacińska M, Szpotkowski K, Ciesiołka J. Poly(C)-binding Protein 2 Regulates the p53 Expression via Interactions with the 5'-Terminal Region of p53 mRNA. Int J Mol Sci 2021; 22:ijms222413306. [PMID: 34948101 PMCID: PMC8708005 DOI: 10.3390/ijms222413306] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 12/03/2021] [Accepted: 12/07/2021] [Indexed: 11/16/2022] Open
Abstract
The p53 protein is one of the major transcriptional factors which guards cell homeostasis. Here, we showed that poly(C)-binding protein 2 (PCBP2) can bind directly to the 5′ terminus of p53 mRNA by means of electrophoretic mobility shift assay. Binding sites of PCBP2 within this region of p53 mRNA were mapped using Pb2+-induced cleavage and SAXS methods. Strikingly, the downregulation of PCBP2 in HCT116 cells resulted in a lower level of p53 protein under normal and stress conditions. Quantitative analysis of p53 mRNA in PCBP2-downregulated cells revealed a lower level of p53 mRNA under normal conditions suggesting the involvement of PCBP2 in p53 mRNA stabilisation. However, no significant change in p53 mRNA level was observed upon PCBP2 depletion under genotoxic stress. Moreover, a higher level of p53 protein in the presence of rapamycin or doxorubicin and the combination of both antibiotics was noticed in PCBP2-overexpressed cells compared to control cells. These observations indicate the potential involvement of PCBP2 in cap-independent translation of p53 mRNA especially occurring under stress conditions. It has been postulated that the PCBP2 protein is engaged in the enhancement of p53 mRNA stability, probably via interacting with its 3′ end. Our data show that under stress conditions PCBP2 also modulates p53 translation through binding to the 5′ terminus of p53 mRNA. Thus PCBP2 emerges as a double-function factor in the p53 expression.
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4
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Gu W, Gong L, Wu X, Yao X. Hypoxic TAM-derived exosomal miR-155-5p promotes RCC progression through HuR-dependent IGF1R/AKT/PI3K pathway. Cell Death Discov 2021; 7:147. [PMID: 34131104 PMCID: PMC8206073 DOI: 10.1038/s41420-021-00525-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 04/30/2021] [Accepted: 05/27/2021] [Indexed: 12/14/2022] Open
Abstract
Hypoxic tumor-associated macrophages (TAMs) are related to poor prognosis of patients with clear cell renal cell carcinoma (ccRCC). Exosomes are small lipid-bilayer vesicles that implicated in tumor progression and metastasis. However, whether hypoxic TAM-derived exosomes affect RCC progression within the hypoxic tumor microenvironment has not been elucidated. GSE analysis identified miR-155-5p was upregulated in RCC. Moreover, we quantified levels of miR-155-5p using RT-qPCR, performed immunohistochemical staining in 79 pairs of primary RCC specimens and related them to clinicopathological parameters. Higher miR-155-5p levels were related to more CD163 + TAM infiltration and elevated HIF-1a expression in our cohort. In the in vitro studies, we initially purified and characterized the exosomes from the supernatant of TAMs subjected to normoxia or hypoxia, and then transfected antagomiR-155-5p or control into these TAMs to produce corresponding exosomes. Gain and loss-of-function studies further investigated the effect of transferred hypoxic exosomal miR-155-5p on the cross-talk between TAMs and RCC cells in xenograft model and in vitro co-culture experiments. The results of RNA immunoprecipitation analyses elucidated that miR-155-5p could directly interact with human antigen R (HuR), thus increasing IGF1R mRNA stability. Mechanistically, hypoxic TAM-Exo transferred miR-155-5p promoted RCC progression partially through activating IGF1R/PI3K/AKT cascades. Taken together, transfer of miR-155-5p from hypoxic TAMs by exosomes to renal cancer cells explains the oncogenic manner, in which M2 macrophages confer the malignant phenotype to RCC cells by enhancing HuR-mediated mRNA stability of IGF1R.
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Affiliation(s)
- Wenyu Gu
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Linjing Gong
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xu Wu
- Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai, China.
| | - Xudong Yao
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China.
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5
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van Vliet T, Casciaro F, Demaria M. To breathe or not to breathe: Understanding how oxygen sensing contributes to age-related phenotypes. Ageing Res Rev 2021; 67:101267. [PMID: 33556549 DOI: 10.1016/j.arr.2021.101267] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/21/2021] [Accepted: 02/02/2021] [Indexed: 02/08/2023]
Abstract
Aging is characterized by a progressive loss of tissue integrity and functionality due to disrupted homeostasis. Molecular oxygen is pivotal to maintain tissue functions, and aerobic species have evolved a sophisticated sensing system to ensure proper oxygen supply and demand. It is not surprising that aberrations in oxygen and oxygen-associated pathways subvert health and promote different aspects of aging. In this review, we discuss emerging findings on how oxygen-sensing mechanisms regulate different cellular and molecular processes during normal physiology, and how dysregulation of oxygen availability lead to disease and aging. We describe various clinical manifestations associated with deregulation of oxygen balance, and how oxygen-modulating therapies and natural oxygen oscillations influence longevity. We conclude by discussing how a better understanding of oxygen-related mechanisms that orchestrate aging processes may lead to the development of new therapeutic strategies to extend healthy aging.
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6
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Zhang C, Liu J, Wang J, Zhang T, Xu D, Hu W, Feng Z. The Interplay Between Tumor Suppressor p53 and Hypoxia Signaling Pathways in Cancer. Front Cell Dev Biol 2021; 9:648808. [PMID: 33681231 PMCID: PMC7930565 DOI: 10.3389/fcell.2021.648808] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Accepted: 01/29/2021] [Indexed: 12/13/2022] Open
Abstract
Hypoxia is a hallmark of solid tumors and plays a critical role in different steps of tumor progression, including proliferation, survival, angiogenesis, metastasis, metabolic reprogramming, and stemness of cancer cells. Activation of the hypoxia-inducible factor (HIF) signaling plays a critical role in regulating hypoxic responses in tumors. As a key tumor suppressor and transcription factor, p53 responds to a wide variety of stress signals, including hypoxia, and selectively transcribes its target genes to regulate various cellular responses to exert its function in tumor suppression. Studies have demonstrated a close but complex interplay between hypoxia and p53 signaling pathways. The p53 levels and activities can be regulated by the hypoxia and HIF signaling differently depending on the cell/tissue type and the severity and duration of hypoxia. On the other hand, p53 regulates the hypoxia and HIF signaling at multiple levels. Many tumor-associated mutant p53 proteins display gain-of-function (GOF) oncogenic activities to promote cancer progression. Emerging evidence has also shown that GOF mutant p53 can promote cancer progression through its interplay with the hypoxia and HIF signaling pathway. In this review, we summarize our current understanding of the interplay between the hypoxia and p53 signaling pathways, its impact upon cancer progression, and its potential application in cancer therapy.
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Affiliation(s)
- Cen Zhang
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers-State University of New Jersey, New Brunswick, NJ, United States
| | - Juan Liu
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers-State University of New Jersey, New Brunswick, NJ, United States
| | - Jianming Wang
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers-State University of New Jersey, New Brunswick, NJ, United States
| | - Tianliang Zhang
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers-State University of New Jersey, New Brunswick, NJ, United States
| | - Dandan Xu
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers-State University of New Jersey, New Brunswick, NJ, United States
| | - Wenwei Hu
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers-State University of New Jersey, New Brunswick, NJ, United States
| | - Zhaohui Feng
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, Rutgers-State University of New Jersey, New Brunswick, NJ, United States
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7
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Shao Z, Ni L, Hu S, Xu T, Meftah Z, Yu Z, Tian N, Wu Y, Sun L, Wu A, Pan Z, Chen L, Gao W, Zhou Y, Zhang X, Wang X. RNA-binding protein HuR suppresses senescence through Atg7 mediated autophagy activation in diabetic intervertebral disc degeneration. Cell Prolif 2020; 54:e12975. [PMID: 33372336 PMCID: PMC7848958 DOI: 10.1111/cpr.12975] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/08/2020] [Accepted: 12/14/2020] [Indexed: 12/13/2022] Open
Abstract
Objectives Diabetes is a risk factor for intervertebral disc degeneration (IVDD). Studies have demonstrated that diabetes may affect IVDD through transcriptional regulation; however, whether post‐transcriptional regulation is involved in diabetic IVDD (DB‐IVDD) is still unknown. This study was performed to illustrate the role of HuR, an RNA‐binding protein, in DB‐IVDD development and its mechanism. Materials and Methods The expression of HuR was evaluated in nucleus pulposus (NP) tissues from diabetic IVDD patients and in high glucose‐treated NP cells. Senescence and autophagy were assessed in HuR over‐expressing and downregulation NP cells. The mRNAs that were regulated by HuR were screened, and immunoprecipitation was applied to confirm the regulation of HuR on targeted mRNAs. Results The results showed that the expression of HuR was decreased in diabetic NP tissues and high glucose‐treated NP cells. Downregulation of HuR may lead to increased senescence in high glucose‐treated NP cells, while autophagy activation attenuates senescence in HuR deficient NP cells. Mechanistic study showed that HuR prompted Atg7 mRNA stability via binding to the AU‐rich elements. Furthermore, overexpression of Atg7, but not HuR, may ameliorate DB‐IVDD in rats in vivo. Conclusions In conclusion, HuR may suppress senescence through autophagy activation via stabilizing Atg7 in diabetic NP cells; while Atg7, but not HuR, may serve as a potential therapeutic target for DB‐IVDD.
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Affiliation(s)
- Zhenxuan Shao
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Libin Ni
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Sunli Hu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Tianzhen Xu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Department of Orthopaedics, Zhuji People's Hospital of Zhejiang Province, China
| | - Zaher Meftah
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Zupo Yu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Naifeng Tian
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Yaosen Wu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Liaojun Sun
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Aimin Wu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Zongyou Pan
- Department of Orthopaedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Linwei Chen
- Department of Orthopaedics, The Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Weiyang Gao
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Yifei Zhou
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Xiaolei Zhang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
| | - Xiangyang Wang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.,Key Laboratory of Orthopaedics of Zhejiang Province, Wenzhou, China.,The Second School of Medicine, Wenzhou Medical University, Wenzhou, China
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8
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Gopu V, Fan L, Shetty RS, Nagaraja M, Shetty S. Caveolin-1 scaffolding domain peptide regulates glucose metabolism in lung fibrosis. JCI Insight 2020; 5:137969. [PMID: 32841217 PMCID: PMC7566714 DOI: 10.1172/jci.insight.137969] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/20/2020] [Indexed: 12/26/2022] Open
Abstract
Increased metabolism distinguishes myofibroblasts or fibrotic lung fibroblasts (fLfs) from the normal lung fibroblasts (nLfs). The mechanism of metabolic activation in fLfs has not been fully elucidated. Furthermore, the antifibrogenic effects of caveolin-1 scaffolding domain peptide CSP/CSP7 involving metabolic reprogramming in fLfs are unclear. We therefore analyzed lactate and succinate levels, as well as the expression of glycolytic enzymes and hypoxia inducible factor-1α (HIF-1α). Lactate and succinate levels, as well as the basal expression of glycolytic enzymes and HIF-1α, were increased in fLfs. These changes were reversed following restoration of p53 or its transcriptional target microRNA-34a (miR-34a) expression in fLfs. Conversely, inhibition of basal p53 or miR-34a increased glucose metabolism, glycolytic enzymes, and HIF-1α in nLfs. Treatment of fLfs or mice having bleomycin- or Ad-TGF-β1-induced lung fibrosis with CSP/CSP7 reduced the expression of glycolytic enzymes and HIF-1α. Furthermore, inhibition of p53 or miR-34a abrogated CSP/CSP7-mediated restoration of glycolytic flux in fLfs in vitro and in mice with pulmonary fibrosis and lacking p53 or miR-34a expression in fibroblasts in vivo. Our data indicate that dysregulation of glucose metabolism in fLfs is causally linked to loss of basal expression of p53 and miR-34a. Treatment with CSP/CSP7 constrains aberrant glucose metabolism through restoration of p53 and miR-34a.
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9
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Lacroix M, Riscal R, Arena G, Linares LK, Le Cam L. Metabolic functions of the tumor suppressor p53: Implications in normal physiology, metabolic disorders, and cancer. Mol Metab 2020; 33:2-22. [PMID: 31685430 PMCID: PMC7056927 DOI: 10.1016/j.molmet.2019.10.002] [Citation(s) in RCA: 188] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/24/2019] [Accepted: 10/05/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The TP53 gene is one of the most commonly inactivated tumor suppressors in human cancers. p53 functions during cancer progression have been linked to a variety of transcriptional and non-transcriptional activities that lead to the tight control of cell proliferation, senescence, DNA repair, and cell death. However, converging evidence indicates that p53 also plays a major role in metabolism in both normal and cancer cells. SCOPE OF REVIEW We provide an overview of the current knowledge on the metabolic activities of wild type (WT) p53 and highlight some of the mechanisms by which p53 contributes to whole body energy homeostasis. We will also pinpoint some evidences suggesting that deregulation of p53-associated metabolic activities leads to human pathologies beyond cancer, including obesity, diabetes, liver, and cardiovascular diseases. MAJOR CONCLUSIONS p53 is activated when cells are metabolically challenged but the origin, duration, and intensity of these stresses will dictate the outcome of the p53 response. p53 plays pivotal roles both upstream and downstream of several key metabolic regulators and is involved in multiple feedback-loops that ensure proper cellular homeostasis. The physiological roles of p53 in metabolism involve complex mechanisms of regulation implicating both cell autonomous effects as well as autocrine loops. However, the mechanisms by which p53 coordinates metabolism at the organismal level remain poorly understood. Perturbations of p53-regulated metabolic activities contribute to various metabolic disorders and are pivotal during cancer progression.
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Affiliation(s)
- Matthieu Lacroix
- Institut de Recherche en Cancérologie de Montpellier, INSERM, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France; Equipe labélisée Ligue Contre le Cancer, France
| | - Romain Riscal
- Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Giuseppe Arena
- Gustave Roussy Cancer Campus, INSERM U1030, Villejuif, France
| | - Laetitia Karine Linares
- Institut de Recherche en Cancérologie de Montpellier, INSERM, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France; Equipe labélisée Ligue Contre le Cancer, France
| | - Laurent Le Cam
- Institut de Recherche en Cancérologie de Montpellier, INSERM, Université de Montpellier, Institut Régional du Cancer de Montpellier, Montpellier, France; Equipe labélisée Ligue Contre le Cancer, France.
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10
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Murphy MR, Kleiman FE. Connections between 3' end processing and DNA damage response: Ten years later. WILEY INTERDISCIPLINARY REVIEWS. RNA 2020; 11:e1571. [PMID: 31657151 PMCID: PMC7295566 DOI: 10.1002/wrna.1571] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/10/2019] [Accepted: 09/17/2019] [Indexed: 12/23/2022]
Abstract
Ten years ago we reviewed how the cellular DNA damage response (DDR) is controlled by changes in the functional and structural properties of nuclear proteins, resulting in a timely coordinated control of gene expression that allows DNA repair. Expression of genes that play a role in DDR is regulated not only at transcriptional level during mRNA biosynthesis but also by changing steady-state levels due to turnover of the transcripts. The 3' end processing machinery, which is important in the regulation of mRNA stability, is involved in these gene-specific responses to DNA damage. Here, we review the latest mechanistic connections described between 3' end processing and DDR, with a special emphasis on alternative polyadenylation, microRNA and RNA binding proteins-mediated deadenylation, and discuss the implications of deregulation of these steps in DDR and human disease. This article is categorized under: RNA Processing > 3' End Processing RNA-Based Catalysis > Miscellaneous RNA-Catalyzed Reactions RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Michael Robert Murphy
- Department of Chemistry, Hunter College and Biochemistry Program, The Graduate Center, City University of New York, New York, New York
| | - Frida Esther Kleiman
- Department of Chemistry, Hunter College and Biochemistry Program, The Graduate Center, City University of New York, New York, New York
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11
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Derech-Haim S, Friedman Y, Hizi A, Bakhanashvili M. p53 regulates its own expression by an intrinsic exoribonuclease activity through AU-rich elements. J Mol Med (Berl) 2020; 98:437-449. [PMID: 32016559 DOI: 10.1007/s00109-020-01884-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 12/26/2019] [Accepted: 01/28/2020] [Indexed: 11/25/2022]
Abstract
The onco-suppressor p53 protein plays also an important role in the control of various aspects of health and disease. p53 levels are low in normal cells and elevated under stress conditions. While low levels of p53 promote tumor formation, overactive p53 leads to premature aging and cell death. RNA degradation is a critical level of regulation contributing to the control of gene expression. p53, as an RNA-binding protein, exerts 3' → 5' exoribonuclease activity, mediating degradation of adenylate/uridylate-rich elements (ARE)-containing ssRNAs. The 3'-UTR of p53-mRNA, which is a target of p53 itself, harbors cis-acting AREs. Our results suggest that p53 controls its own expression through murine double-minute 2 (mdm2)-independent "RNA decay" function in cytoplasm. We demonstrate that p53 expresses an exoribonuclease activity through the binding to ARE sequences of p53-mRNA via translation-independent and translation-dependent polysome-associated pathways. Antagonistic interplay was detected between p53 levels and execution of its exoribonuclease function mirrored in low p53 levels in normal cells, due to the efficient exoribonuclease activity, and in the accumulation of p53 in cells exposed to p53-activating drugs in accordance with the reduced exoribonuclease activity. Apparently, p53, via control of its own mRNA stability and/or translation in cytoplasm, might act as a negative regulator of p53-mRNA levels. The observed connection between exoribonuclease activity and p53 abundance highlights the importance of this function affecting p53 expression, imperative for multiple functions, with implications for the steady-state levels of protein and for the p53 stress response. The modulation in expression of exoribonuclease activity would be translated into the alterations in p53 level. KEY MESSAGES: p53 controls its own expression through mdm2-independent "RNA decay" function in cytoplasm. p53 expresses an exoribonuclease activity through the binding to ARE sequences of p53-mRNA. Antagonistic interplay exists between stress-induced p53 and execution of its exoribonuclease function.
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Affiliation(s)
- Sanaz Derech-Haim
- Infectious Diseases Unit, Sheba Medical Center, 5265601, Tel-Hashomer, Israel
| | - Yael Friedman
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 5290002, Ramat-Gan, Israel
| | - Amnon Hizi
- Department of Cellular and Developmental Biology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mary Bakhanashvili
- Infectious Diseases Unit, Sheba Medical Center, 5265601, Tel-Hashomer, Israel.
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, 5290002, Ramat-Gan, Israel.
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12
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Haronikova L, Olivares-Illana V, Wang L, Karakostis K, Chen S, Fåhraeus R. The p53 mRNA: an integral part of the cellular stress response. Nucleic Acids Res 2019; 47:3257-3271. [PMID: 30828720 PMCID: PMC6468297 DOI: 10.1093/nar/gkz124] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2018] [Revised: 02/12/2019] [Accepted: 02/21/2019] [Indexed: 12/16/2022] Open
Abstract
A large number of signalling pathways converge on p53 to induce different cellular stress responses that aim to promote cell cycle arrest and repair or, if the damage is too severe, to induce irreversible senescence or apoptosis. The differentiation of p53 activity towards specific cellular outcomes is tightly regulated via a hierarchical order of post-translational modifications and regulated protein-protein interactions. The mechanisms governing these processes provide a model for how cells optimize the genetic information for maximal diversity. The p53 mRNA also plays a role in this process and this review aims to illustrate how protein and RNA interactions throughout the p53 mRNA in response to different signalling pathways control RNA stability, translation efficiency or alternative initiation of translation. We also describe how a p53 mRNA platform shows riboswitch-like features and controls the rate of p53 synthesis, protein stability and modifications of the nascent p53 protein. A single cancer-derived synonymous mutation disrupts the folding of this platform and prevents p53 activation following DNA damage. The role of the p53 mRNA as a target for signalling pathways illustrates how mRNA sequences have co-evolved with the function of the encoded protein and sheds new light on the information hidden within mRNAs.
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Affiliation(s)
- Lucia Haronikova
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53 Brno, Czech Republic
| | - Vanesa Olivares-Illana
- Laboratorio de Interacciones Biomoleculares y cáncer. Instituto de Física Universidad Autónoma de San Luis Potosí, Manuel Nava 6, Zona universitaria, 78290 SLP, México
| | - Lixiao Wang
- Department of Medical Biosciences, Umeå University, 90185 Umeå, Sweden
| | | | - Sa Chen
- Department of Medical Biosciences, Umeå University, 90185 Umeå, Sweden
| | - Robin Fåhraeus
- RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53 Brno, Czech Republic.,Department of Medical Biosciences, Umeå University, 90185 Umeå, Sweden.,Inserm U1162, 27 rue Juliette Dodu, 75010 Paris, France.,ICCVS, University of Gdańsk, Science, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
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13
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Kim EK, Lee SY, Kim Y, Ahn SM, Jang HH. Peroxiredoxin 1 post-transcriptionally regulates snoRNA expression. Free Radic Biol Med 2019; 141:1-9. [PMID: 31158443 DOI: 10.1016/j.freeradbiomed.2019.05.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/28/2019] [Accepted: 05/28/2019] [Indexed: 11/28/2022]
Abstract
Peroxiredoxin 1 (Prx1) is a member of the Prx family that detoxifies various peroxide substrates through conserved catalytic cysteine residues with the use of reducing equivalents. In addition to this well-known role of Prx1, we have previously demonstrated that Prx1 also has RNA-binding properties, but its function as an RNA-binding protein (RBP) remains unknown. To characterize the role of Prx1 as an RBP, we pulled down Prx1-RNA complexes and sequenced the target RNAs of Prx1. Through sequencing and further validation studies, we revealed that Prx1 binds to a specific subset of small nucleolar RNAs (snoRNAs) and regulates these molecules at the post-transcriptional level. We also found that active cysteine residues provide a structural and functional link between these two distinct functions of Prx1 (i.e., ROS scavenging and RNA-binding activities). Prx1 functions as a snoRNA-binding protein in its reduced state, and post-transcriptionally regulates the expression of a set of snoRNAs. However, when the active cysteine residues are oxidized, Prx1 loses its activity as a snoRNA-binding protein. This study is the first report describing the novel role of Prx1 as a post-transcriptional regulator of snoRNAs.
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Affiliation(s)
- Eun-Kyung Kim
- Department of Biochemistry, College of Medicine, Gachon University, Incheon, 21999, Republic of Korea
| | - Sun Young Lee
- Center for Cancer Genome Discovery, Asan Institute for Life Science, University of Ulsan College of Medicine, Asan Medical Center, Seoul, 05505, Republic of Korea
| | - Yosup Kim
- Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, 21999, Republic of Korea
| | - Sung-Min Ahn
- Department of Genome Medicine and Science, College of Medicine, Gachon University, Incheon, 21936, Republic of Korea; Division of Medical Oncology, Department of Internal Medicine, Gachon University Gil Medical Center, Incheon, 21565, Republic of Korea.
| | - Ho Hee Jang
- Department of Biochemistry, College of Medicine, Gachon University, Incheon, 21999, Republic of Korea; Department of Health Sciences and Technology, GAIHST, Gachon University, Incheon, 21999, Republic of Korea.
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14
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Minervini G, Quaglia F, Tabaro F, Tosatto SCE. Genotype-phenotype relations of the von Hippel-Lindau tumor suppressor inferred from a large-scale analysis of disease mutations and interactors. PLoS Comput Biol 2019; 15:e1006478. [PMID: 30943211 PMCID: PMC6464237 DOI: 10.1371/journal.pcbi.1006478] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Revised: 04/15/2019] [Accepted: 02/25/2019] [Indexed: 02/06/2023] Open
Abstract
Familiar cancers represent a privileged point of view for studying the complex cellular events inducing tumor transformation. Von Hippel-Lindau syndrome, a familiar predisposition to develop cancer is a clear example. Here, we present our efforts to decipher the role of von Hippel-Lindau tumor suppressor protein (pVHL) in cancer insurgence. We collected high quality information about both pVHL mutations and interactors to investigate the association between patient phenotypes, mutated protein surface and impaired interactions. Our data suggest that different phenotypes correlate with localized perturbations of the pVHL structure, with specific cell functions associated to different protein surfaces. We propose five different pVHL interfaces to be selectively involved in modulating proteins regulating gene expression, protein homeostasis as well as to address extracellular matrix (ECM) and ciliogenesis associated functions. These data were used to drive molecular docking of pVHL with its interactors and guide Petri net simulations of the most promising alterations. We predict that disruption of pVHL association with certain interactors can trigger tumor transformation, inducing metabolism imbalance and ECM remodeling. Collectively taken, our findings provide novel insights into VHL-associated tumorigenesis. This highly integrated in silico approach may help elucidate novel treatment paradigms for VHL disease.
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Affiliation(s)
| | - Federica Quaglia
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Francesco Tabaro
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Silvio C. E. Tosatto
- Department of Biomedical Sciences, University of Padova, Padova, Italy
- CNR Institute of Neuroscience, Padova, Padova, Italy
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15
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Ramos-Alonso L, Romero AM, Soler MÀ, Perea-García A, Alepuz P, Puig S, Martínez-Pastor MT. Yeast Cth2 protein represses the translation of ARE-containing mRNAs in response to iron deficiency. PLoS Genet 2018; 14:e1007476. [PMID: 29912874 PMCID: PMC6023232 DOI: 10.1371/journal.pgen.1007476] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 06/28/2018] [Accepted: 06/07/2018] [Indexed: 11/29/2022] Open
Abstract
In response to iron deficiency, the budding yeast Saccharomyces cerevisiae undergoes a metabolic remodeling in order to optimize iron utilization. The tandem zinc finger (TZF)-containing protein Cth2 plays a critical role in this adaptation by binding and promoting the degradation of multiple mRNAs that contain AU-rich elements (AREs). Here, we demonstrate that Cth2 also functions as a translational repressor of its target mRNAs. By complementary approaches, we demonstrate that Cth2 protein inhibits the translation of SDH4, which encodes a subunit of succinate dehydrogenase, and CTH2 mRNAs in response to iron depletion. Both the AREs within SDH4 and CTH2 transcripts, and the Cth2 TZF are essential for translational repression. We show that the role played by Cth2 as a negative translational regulator extends to other mRNA targets such as WTM1, CCP1 and HEM15. A structure-function analysis of Cth2 protein suggests that the Cth2 amino-terminal domain (NTD) is important for both mRNA turnover and translation inhibition, while its carboxy-terminal domain (CTD) only participates in the regulation of translation, but is dispensable for mRNA degradation. Finally, we demonstrate that the Cth2 CTD is physiologically relevant for adaptation to iron deficiency. Iron is essential for eukaryotes because it is required for many fundamental processes such as DNA replication, protein translation or respiration, but it is very insoluble and can, therefore, easily go scarce. For this reason, eukaryotic cells have developed adaptive responses to iron deficiency. Under iron limitation conditions, the yeast Saccharomyces cerevisiae induces the expression of Cth2, a protein with tandem zinc fingers that binds to adenine and uracil-rich sequences in the 3’-UTR of specific mRNAs related to iron metabolism, promoting their degradation. Here we show that Cth2 inhibits the translation of ARE-containing mRNAs, including SDH4, WTM1, HEM15 and CCP1, which encode proteins that contain iron or participate in iron-dependent pathways, and CTH2 itself, which is subjected to an autoregulatory loop that controls its expression. We also dissected different domains of Cth2 that are differentially involved in mRNA decay and translational inhibition. The involvement of Cth2 in translational control reinforces the importance of this ARE-binding protein as a post-transcriptional regulator of the iron response in yeast. By acting at different steps in the life of specific mRNA targets, Cth2 action ensures yeast cells a proper distribution of iron by optimizing its utilization in essential processes.
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Affiliation(s)
- Lucía Ramos-Alonso
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Antonia María Romero
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Maria Àngel Soler
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Valencia, Spain
| | - Ana Perea-García
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
| | - Paula Alepuz
- Departamento de Bioquímica y Biología Molecular, Universitat de València, Valencia, Spain
- ERI Biotecmed, Universitat de València, Burjassot, Valencia, Spain
| | - Sergi Puig
- Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos (IATA), Consejo Superior de Investigaciones Científicas (CSIC), Paterna, Valencia, Spain
- * E-mail: (MTMP); (SP)
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16
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Li XL, Subramanian M, Jones MF, Chaudhary R, Singh DK, Zong X, Gryder B, Sindri S, Mo M, Schetter A, Wen X, Parvathaneni S, Kazandjian D, Jenkins LM, Tang W, Elloumi F, Martindale JL, Huarte M, Zhu Y, Robles AI, Frier SM, Rigo F, Cam M, Ambs S, Sharma S, Harris CC, Dasso M, Prasanth KV, Lal A. Long Noncoding RNA PURPL Suppresses Basal p53 Levels and Promotes Tumorigenicity in Colorectal Cancer. Cell Rep 2018; 20:2408-2423. [PMID: 28877474 DOI: 10.1016/j.celrep.2017.08.041] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 07/21/2017] [Accepted: 08/09/2017] [Indexed: 12/13/2022] Open
Abstract
Basal p53 levels are tightly suppressed under normal conditions. Disrupting this regulation results in elevated p53 levels to induce cell cycle arrest, apoptosis, and tumor suppression. Here, we report the suppression of basal p53 levels by a nuclear, p53-regulated long noncoding RNA that we termed PURPL (p53 upregulated regulator of p53 levels). Targeted depletion of PURPL in colorectal cancer cells results in elevated basal p53 levels and induces growth defects in cell culture and in mouse xenografts. PURPL associates with MYBBP1A, a protein that binds to and stabilizes p53, and inhibits the formation of the p53-MYBBP1A complex. In the absence of PURPL, MYBBP1A interacts with and stabilizes p53. Silencing MYBBP1A significantly rescues basal p53 levels and proliferation in PURPL-deficient cells, suggesting that MYBBP1A mediates the effect of PURPL in regulating p53. These results reveal a p53-PURPL auto-regulatory feedback loop and demonstrate a role for PURPL in maintaining basal p53 levels.
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Affiliation(s)
- Xiao Ling Li
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, MD 20892, USA
| | - Murugan Subramanian
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, MD 20892, USA
| | - Matthew F Jones
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, MD 20892, USA
| | - Ritu Chaudhary
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, MD 20892, USA
| | - Deepak K Singh
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Xinying Zong
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Berkley Gryder
- Oncogenomics Section, Genetics Branch, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Sivasish Sindri
- Oncogenomics Section, Genetics Branch, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Min Mo
- Laboratory of Gene Regulation and Development, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | - Aaron Schetter
- Molecular Genetics and Carcinogenesis Section, Laboratory of Human Carcinogenesis, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Xinyu Wen
- Oncogenomics Section, Genetics Branch, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Swetha Parvathaneni
- Department of Biochemistry and Molecular Biology, College of Medicine, Howard University, Washington, DC 20059, USA
| | - Dickran Kazandjian
- Molecular Genetics and Carcinogenesis Section, Laboratory of Human Carcinogenesis, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Lisa M Jenkins
- Laboratory of Cell Biology, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Wei Tang
- Molecular Epidemiology Section, Laboratory of Human Carcinogenesis, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Fathi Elloumi
- Office of Science and Technology Resources, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Jennifer L Martindale
- Laboratory of Genetics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD 21224, USA
| | - Maite Huarte
- Center for Applied Medical Research, Department of Gene Therapy and Regulation of Gene Expression, University of Navarra, 31008 Pamplona, Spain
| | - Yuelin Zhu
- Molecular Genetics Section, Genetics Branch, CCR, NCI, NIH, Bethesda, MD 28092, USA
| | - Ana I Robles
- Molecular Genetics and Carcinogenesis Section, Laboratory of Human Carcinogenesis, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | | | - Frank Rigo
- Ionis Pharmaceuticals, Carlsbad, CA 92010, USA
| | - Maggie Cam
- Office of Science and Technology Resources, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Stefan Ambs
- Molecular Epidemiology Section, Laboratory of Human Carcinogenesis, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Sudha Sharma
- Department of Biochemistry and Molecular Biology, College of Medicine, Howard University, Washington, DC 20059, USA
| | - Curtis C Harris
- Molecular Genetics and Carcinogenesis Section, Laboratory of Human Carcinogenesis, CCR, NCI, NIH, Bethesda, MD 20892, USA
| | - Mary Dasso
- Laboratory of Gene Regulation and Development, National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA
| | - Kannanganattu V Prasanth
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Ashish Lal
- Regulatory RNAs and Cancer Section, Genetics Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), NIH, Bethesda, MD 20892, USA.
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17
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Jaiswal PK, Koul S, Shanmugam PST, Koul HK. Eukaryotic Translation Initiation Factor 4 Gamma 1 (eIF4G1) is upregulated during Prostate cancer progression and modulates cell growth and metastasis. Sci Rep 2018; 8:7459. [PMID: 29748619 PMCID: PMC5945649 DOI: 10.1038/s41598-018-25798-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 04/27/2018] [Indexed: 12/18/2022] Open
Abstract
eIF4G1, a critical component of the eIF4F complex, is required for cap-dependent mRNA translation, a process necessary for tumor growth and survival. However, the role of eIF4G1 has not been evaluated in Prostate Cancer (PCa). We observed an increased eIF4G1 protein levels in PCa tissues as compared to normal tissues. Analysis of the TCGA data revealed that eIF4G1 gene expression positively correlated with higher tumor grade and stage. Furthermore, eIF4G1 was over-expressed and or amplified, in 16% patients with metastatic PCa (SU2C/PCF Dream Team dataset) and in 59% of castration-resistant prostate cancer (CRPC) patients (Trento/Cornell/Broad dataset). We showed for the first time that eIF4G1 expression was increased in PCa and that increased eIF4G1 expression associated with tumor progression and metastasis. We also observed high protein levels of eIF4G1 in PCa cell lines and prostate tissues from the TRAMP model of PCa as compared to normal prostate cell line and prostate tissues from the wild type mice. Knockdown of eIF4G1 in PCa cells resulted in decreased Cyclin D1 and p-Rb protein level, cell cycle delay, reduced cell viability and proliferation, impaired clonogenic activity, reduced cell migration and decreased mRNA loading to polysomes. Treatment with eIF4G complex inhibitor also impaired prostasphere formation. eIF4G1 knockdown or treatment with eIF4G complex inhibitor sensitized CRPC cells to Enzalutamide and Bicalutamide. Our results showed that eIF4G1 plays an important role in PCa growth and therapeutic resistance. These data suggested that eIF4G1 functions as an oncoprotein and may serve as a novel target for intervention in PCa and CRPC.
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Affiliation(s)
- Praveen Kumar Jaiswal
- Department of Biochemistry and Molecular Biology, LSU Health Sciences Center, Shreveport, 1501 Kings Highway, LA, 71130, USA
| | - Sweaty Koul
- Department of Urology, LSU Health Sciences Center, Shreveport, 1501 Kings Highway, LA 71130, USA
- Feist Weiller Cancer Center, Shreveport, 1501 Kings Highway, LA, 71130, USA
| | - Prakash S T Shanmugam
- Department of Biochemistry and Molecular Biology, LSU Health Sciences Center, Shreveport, 1501 Kings Highway, LA, 71130, USA
| | - Hari K Koul
- Department of Biochemistry and Molecular Biology, LSU Health Sciences Center, Shreveport, 1501 Kings Highway, LA, 71130, USA.
- Overton Brooks Veterans Administration Medical Center, Shreveport, LA, USA.
- Feist Weiller Cancer Center, Shreveport, 1501 Kings Highway, LA, 71130, USA.
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18
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Induction of the p53 Tumor Suppressor in Cancer Cells through Inhibition of Cap-Dependent Translation. Mol Cell Biol 2018; 38:MCB.00367-17. [PMID: 29483299 DOI: 10.1128/mcb.00367-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 02/18/2018] [Indexed: 12/17/2022] Open
Abstract
The p53 tumor suppressor plays a critical role in protecting normal cells from malignant transformation. Development of small molecules to reactivate p53 in cancer cells has been an area of intense research. We previously identified an internal ribosomal entry site (IRES) within the 5' untranslated region of p53 mRNA that mediates translation of the p53 mRNA independent of cap-dependent translation. Our results also show that in response to DNA damage, cells switch from cap-dependent translation to cap-independent translation of p53 mRNA. In the present study, we discovered a specific inhibitor of cap-dependent translation, 4EGI-1, that is capable of inducing the accumulation of p53 in cancer cells retaining wild-type p53. Our results show that 4EGI-1 causes an increase in p53 IRES activity, leading to increased translation of p53 mRNA. We also observed that 4EGI-1 induces cancer cell apoptosis in a p53-dependent manner. Furthermore, 4EGI-1 induces p53 in cancer cells without causing DNA double-strand breaks. In conclusion, we discovered a mechanistic link between inhibition of cap-dependent translation and enhanced p53 accumulation. This leads to apoptosis of cancer cells without causing collateral damage to normal cells, thus providing a novel and effective therapeutic strategy for cancer.
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19
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Razafinjatovo CF, Stiehl D, Deininger E, Rechsteiner M, Moch H, Schraml P. VHL missense mutations in the p53 binding domain show different effects on p53 signaling and HIFα degradation in clear cell renal cell carcinoma. Oncotarget 2018; 8:10199-10212. [PMID: 28052007 PMCID: PMC5354652 DOI: 10.18632/oncotarget.14372] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 12/15/2016] [Indexed: 11/25/2022] Open
Abstract
Clear cell Renal Cell Carcinoma (ccRCC) formation is connected to functional loss of the von Hippel-Lindau (VHL) gene. Recent data identified its gene product, pVHL, as a multifunctional adaptor protein which interacts with HIFα subunits but also with the tumor suppressor p53. p53 is hardly expressed and rarely mutated in most ccRCC. We showed that low and absent p53 expression correlated with the severity of VHL mutations in 262 analyzed ccRCC tissues. In contrast to nonsense and frameshift mutations which abrogate virtually all pVHL functions, missense mutations may rather influence one or few functions. Therefore, we focused on four VHL missense mutations, which affect the overlapping pVHL binding sites of p53 and Elongin C, by investigating their impact on HIFα degradation, p53 expression and signaling, as well as on cellular behavior using ccRCC cell lines and tissues. TP53 mRNA and its effector targets p21, Bax and Noxa, were altered both in engineered cell lines and in tumor tissues which carried the same missense mutations. Two of these mutations were not able to degrade HIFα whereas the remaining two mutations led to HIFα downregulation, suggesting the latter are p53 binding site-specific. The selected VHL missense mutations further enhanced tumor cell survival, but had no effects on cell proliferation. Whereas Sunitinib was able to efficiently reduce cell proliferation, Camptothecin was additionally able to increase apoptotic activity of the tumor cells. It is concluded that systematic characterization of the VHL mutation status may help optimizing targeted therapy for patients with metastatic ccRCC.
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Affiliation(s)
| | - Daniel Stiehl
- Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Eva Deininger
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Markus Rechsteiner
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Holger Moch
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
| | - Peter Schraml
- Department of Pathology and Molecular Pathology, University Hospital Zurich, Zurich, Switzerland
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20
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Truntipakorn A, Makeudom A, Sastraruji T, Pavasant P, Pattamapun K, Krisanaprakornkit S. Effects of prostaglandin E 2 on clonogenicity, proliferation and expression of pluripotent markers in human periodontal ligament cells. Arch Oral Biol 2017; 83:130-135. [DOI: 10.1016/j.archoralbio.2017.07.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 07/17/2017] [Accepted: 07/24/2017] [Indexed: 12/11/2022]
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21
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Shang J, Zhao Z. Emerging role of HuR in inflammatory response in kidney diseases. Acta Biochim Biophys Sin (Shanghai) 2017; 49:753-763. [PMID: 28910975 DOI: 10.1093/abbs/gmx071] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Accepted: 06/21/2017] [Indexed: 12/14/2022] Open
Abstract
Human antigen R (HuR) is a member of the embryonic lethal abnormal vision (ELAV) family which can bind to the A/U rich elements in 3' un-translated region of mRNA and regulate mRNA splicing, transportation, and stability. Unlike other members of the ELAV family, HuR is ubiquitously expressed. Early studies mainly focused on HuR function in malignant diseases. As researches proceed, more and more proofs demonstrate its relationship with inflammation. Since most kidney diseases involve pathological changes of inflammation, HuR is now suggested to play a pivotal role in glomerular nephropathy, tubular ischemia-reperfusion damage, renal fibrosis and even renal tumors. By regulating the mRNAs of target genes, HuR is causally linked to the onset and progression of kidney diseases. Reports on this topic are steadily increasing, however, the detailed function and mechanism of action of HuR are still not well understood. The aim of this review article is to summarize the present understanding of the role of HuR in inflammation in kidney diseases, and we anticipate that future research will ultimately elucidate the therapeutic value of this novel target.
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Affiliation(s)
- Jin Shang
- Nephrology Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Zhanzheng Zhao
- Nephrology Hospital, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
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22
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Kim H, Greenald D, Vettori A, Markham E, Santhakumar K, Argenton F, van Eeden F. Zebrafish as a model for von Hippel Lindau and hypoxia-inducible factor signaling. Methods Cell Biol 2017; 138:497-523. [DOI: 10.1016/bs.mcb.2016.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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23
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Brodaczewska KK, Szczylik C, Fiedorowicz M, Porta C, Czarnecka AM. Choosing the right cell line for renal cell cancer research. Mol Cancer 2016; 15:83. [PMID: 27993170 PMCID: PMC5168717 DOI: 10.1186/s12943-016-0565-8] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 11/30/2016] [Indexed: 01/08/2023] Open
Abstract
Cell lines are still a tool of choice for many fields of biomedical research, including oncology. Although cancer is a very complex disease, many discoveries have been made using monocultures of established cell lines. Therefore, the proper use of in vitro models is crucial to enhance our understanding of cancer. Therapeutics against renal cell cancer (RCC) are also screened with the use of cell lines. Multiple RCC in vitro cultures are available, allowing in vivo heterogeneity in the laboratory, but at the same time, these can be a source of errors. In this review, we tried to sum up the data on the RCC cell lines used currently. An increasing amount of data on RCC shed new light on the molecular background of the disease; however, it revealed how much still needs to be done. As new types of RCC are being distinguished, novel cell lines and the re-exploration of old ones seems to be indispensable to create effective in vitro tools for drug screening and more.
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Affiliation(s)
- Klaudia K Brodaczewska
- Department of Oncology with Laboratory of Molecular Oncology, Military Institute of Medicine, Szaserow 128, 04-141, Warsaw, Poland
| | - Cezary Szczylik
- Department of Oncology with Laboratory of Molecular Oncology, Military Institute of Medicine, Szaserow 128, 04-141, Warsaw, Poland
| | - Michal Fiedorowicz
- Department of Experimental Pharmacology, Polish Academy of Science Medical Research Centre, Warsaw, Poland
| | - Camillo Porta
- Department of Medical Oncology, IRCCS San Matteo University Hospital Foundation, Pavia, Italy
| | - Anna M Czarnecka
- Department of Oncology with Laboratory of Molecular Oncology, Military Institute of Medicine, Szaserow 128, 04-141, Warsaw, Poland.
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Abstract
Since its discovery more than three decades ago, tumor suppressor p53 has been shown to play pivotal roles in both maintaining genomic integrity and tumor suppression. p53 functions as a transcription factor responding to a multitude of cellular stressors, regulating the transcription of many genes involved in cell-cycle arrest, senescence, autophagy, and apoptosis. Extensive work has revealed that p53 is one of the most commonly mutated tumor suppressor genes. The last three decades have demonstrated that p53 activity is controlled through transcriptional regulation and posttranslational modifications. However, evolving work is now uncovering that p53, and other p53 family members, are post-transcriptionally regulated by multiple RNA-binding proteins (RBPs). Understanding the regulation of p53 by RBPs may potentially open up the possibility for cancer therapeutic intervention. This review focuses on the posttranscriptional regulation of p53, and p53 family members, by RNA binding proteins and the reciprocal feedback pathways between several RNA-biding proteins modulating p53, and p53 family members.
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Affiliation(s)
- Chris Lucchesi
- Comparative Oncology Laboratory, School of Veterinary Medicine, School of Medicine, University of California at Davis, Davis, California 95616, USA
| | - Jin Zhang
- Comparative Oncology Laboratory, School of Veterinary Medicine, School of Medicine, University of California at Davis, Davis, California 95616, USA
| | - Xinbin Chen
- Comparative Oncology Laboratory, School of Veterinary Medicine, School of Medicine, University of California at Davis, Davis, California 95616, USA
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The RNA binding protein HuR determines the differential translation of autism-associated FoxP subfamily members in the developing neocortex. Sci Rep 2016; 6:28998. [PMID: 27383233 PMCID: PMC4935837 DOI: 10.1038/srep28998] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 06/13/2016] [Indexed: 12/21/2022] Open
Abstract
Forkhead-box domain (Fox) containing family members are known to play a role in neocorticogenesis and have also been associated with disorders on the autism spectrum. Here we show that a single RNA-binding protein, Hu antigen R (HuR), dictates translation specificity of bound mRNAs and is sufficient to define distinct Foxp-characterized subpopulations of neocortical projection neurons. Furthermore, distinct phosphorylation states of HuR differentially regulate translation of Foxp mRNAs in vitro. This demonstrates the importance of RNA binding proteins within the framework of the developing brain and further confirms the role of mRNA translation in autism pathogenesis.
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Newman R, McHugh J, Turner M. RNA binding proteins as regulators of immune cell biology. Clin Exp Immunol 2015. [PMID: 26201441 DOI: 10.1111/cei.12684] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Sequence-specific RNA binding proteins (RBP) are important regulators of the immune response. RBP modulate gene expression by regulating splicing, polyadenylation, localization, translation and decay of target mRNAs. Increasing evidence suggests that RBP play critical roles in the development, activation and function of lymphocyte populations in the immune system. This review will discuss the post-transcriptional regulation of gene expression by RBP during lymphocyte development, with particular focus on the Tristetraprolin family of RBP.
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Affiliation(s)
- R Newman
- Babraham Institute, Cambridge, UK
| | - J McHugh
- Babraham Institute, Cambridge, UK
| | - M Turner
- Babraham Institute, Cambridge, UK
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Singh MM, Johnson B, Venkatarayan A, Flores ER, Zhang J, Su X, Barton M, Lang F, Chandra J. Preclinical activity of combined HDAC and KDM1A inhibition in glioblastoma. Neuro Oncol 2015; 17:1463-73. [PMID: 25795306 DOI: 10.1093/neuonc/nov041] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 02/19/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Glioblastoma (GBM) is the most common and aggressive form of brain cancer. Our previous studies demonstrated that combined inhibition of HDAC and KDM1A increases apoptotic cell death in vitro. However, whether this combination also increases death of the glioma stem cell (GSC) population or has an effect in vivo is yet to be determined. Therefore, we evaluated the translational potential of combined HDAC and KDM1A inhibition on patient-derived GSCs and xenograft GBM mouse models. We also investigated the changes in transcriptional programing induced by the combination in an effort to understand the induced molecular mechanisms of GBM cell death. METHODS Patient-derived GSCs were treated with the combination of vorinostat, a pan-HDAC inhibitor, and tranylcypromine, a KDM1A inhibitor, and viability was measured. To characterize transcriptional profiles associated with cell death, we used RNA-Seq and validated gene changes by RT-qPCR and protein expression via Western blot. Apoptosis was measured using DNA fragmentation assays. Orthotopic xenograft studies were conducted to evaluate the effects of the combination on tumorigenesis and to validate gene changes in vivo. RESULTS The combination of vorinostat and tranylcypromine reduced GSC viability and displayed efficacy in the U87 xenograft model. Additionally, the combination led to changes in apoptosis-related genes, particularly TP53 and TP73 in vitro and in vivo. CONCLUSIONS These data support targeting HDACs and KDM1A in combination as a strategy for GBM and identifies TP53 and TP73 as being altered in response to treatment.
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Affiliation(s)
- Melissa M Singh
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
| | - Blake Johnson
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
| | - Avinashnarayan Venkatarayan
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
| | - Elsa R Flores
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
| | - Jianping Zhang
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
| | - Xiaoping Su
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
| | - Michelle Barton
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
| | - Frederick Lang
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
| | - Joya Chandra
- Department of Pediatrics Research, University of Texas MD Anderson Cancer Center, Houston, Texas (M.M.S., B.J., J.C.); Department of Molecular and Cellular Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (A.V., E.R.F.); Department of Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, Texas (M.B., J.C.); Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (J.Z., X.S.); Department of Neurosurgery, University of Texas MD Anderson Cancer Center, Houston, Texas (B.J., F.L.); Graduate School of Biomedical Sciences, University of Texas Health Science Center, Houston, Texas (A.V., E.R.F., M.B., F.L., J.C.)
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Abstract
Since the Von Hippel-Lindau (VHL) disease tumour suppressor gene VHL was identified in 1993 as the genetic basis for a rare disorder, it has proved to be of wide medical and scientific interest. VHL tumour suppressor protein (pVHL) plays a key part in cellular oxygen sensing by targeting hypoxia-inducible factors for ubiquitylation and proteasomal degradation. Early inactivation of VHL is commonly seen in clear-cell renal cell carcinoma (ccRCC), and insights gained from the functional analysis of pVHL have provided the foundation for the routine treatment of advanced-stage ccRCC with novel targeted therapies. However, recent sequencing studies have identified additional driver genes that are involved in the pathogenesis of ccRCC. As our understanding of the importance of VHL matures, it is timely to review progress from its initial description to current knowledge of VHL biology, as well as future prospects for novel medical treatments for VHL disease and ccRCC.
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Affiliation(s)
- Lucy Gossage
- 1] Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK. [2] Department of Oncology, University of Cambridge, Box 193, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK. [3] Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge CB2 0RE, UK
| | - Tim Eisen
- 1] Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK. [2] Department of Oncology, University of Cambridge, Box 193, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
| | - Eamonn R Maher
- 1] Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK. [2] Department of Medical Genetics, University of Cambridge and NIHR Cambridge Biomedical Research Centre, Box 238, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK
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Abstract
The RNA-binding protein Elavl1 (also known as HuR) regulates gene expression at the posttranscriptional level. Early embryonic lethality of the mouse knockout challenges investigation into hematopoietic functions for Elavl1. We identified 2 zebrafish elavl1 genes, designated elavl1a (the predominant isoform during embryogenesis) and elavl1b. Knockdown of Elavl1a using specific morpholinos resulted in a striking loss of primitive embryonic erythropoiesis. Transcript levels for early hematopoietic regulatory genes including lmo2 and scl are unaltered, but levels of gata1 transcripts, encoding a key erythroid transcription factor, are significantly reduced in elavl1a morphants. Other mesoderm markers are mostly unchanged by depletion of Elav1a. The 3'-untranslated region (UTR) of gata1 contains putative Elavl1a-binding sites that support robust expression levels when fused to a transfected luciferase reporter gene, and Elavl1a binds the gata1 3'-UTR sequences in a manner dependent on these sites. Moreover, expression of a transgenic reporter specifically in developing embryonic erythroid cells is enhanced by addition of the gata1 3'UTR with intact Elavl1-binding sites. Injection of gata1 messenger RNA partially rescues the erythropoiesis defect caused by Elavl1 knockdown. Our study reveals a posttranscriptional regulatory mechanism by which RNA-binding protein Elavl1a regulates embryonic erythropoiesis by maintaining appropriate levels of gata1 expression.
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Chemotherapy-mediated p53-dependent DNA damage response in clear cell renal cell carcinoma: role of the mTORC1/2 and hypoxia-inducible factor pathways. Cell Death Dis 2013; 4:e865. [PMID: 24136229 PMCID: PMC3920935 DOI: 10.1038/cddis.2013.395] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/01/2013] [Accepted: 09/03/2013] [Indexed: 12/23/2022]
Abstract
The DNA-damaging agent camptothecin (CPT) and its analogs demonstrate clinical utility for the treatment of advanced solid tumors, and CPT-based nanopharmaceuticals are currently in clinical trials for advanced kidney cancer; however, little is known regarding the effects of CPT on hypoxia-inducible factor-2α (HIF-2α) accumulation and activity in clear cell renal cell carcinoma (ccRCC). Here we assessed the effects of CPT on the HIF/p53 pathway. CPT demonstrated striking inhibition of both HIF-1α and HIF-2α accumulation in von Hippel–Lindau (VHL)-defective ccRCC cells, but surprisingly failed to inhibit protein levels of HIF-2α-dependent target genes (VEGF, PAI-1, ET-1, cyclin D1). Instead, CPT induced DNA damage-dependent apoptosis that was augmented in the presence of pVHL. Further analysis revealed CPT regulated endothelin-1 (ET-1) in a p53-dependent manner: CPT increased ET-1 mRNA abundance in VHL-defective ccRCC cell lines that was significantly augmented in their VHL-expressing counterparts that displayed increased phosphorylation and accumulation of p53; p53 siRNA suppressed CPT-induced increase in ET-1 mRNA, as did an inhibitor of ataxia telangiectasia mutated (ATM) signaling, suggesting a role for ATM-dependent phosphorylation of p53 in the induction of ET-1. Finally, we demonstrate that p53 phosphorylation and accumulation is partially dependent on mTOR activity in ccRCC. Consistent with this result, pharmacological inhibition of mTORC1/2 kinase inhibited CPT-mediated ET-1 upregulation, and p53-dependent responses in ccRCC. Collectively, these data provide mechanistic insight into the action of CPT in ccRCC, identify ET-1 as a p53-regulated gene and demonstrate a requirement of mTOR for p53-mediated responses in this tumor type.
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Szymanski JJ, Wang H, Jamison JT, DeGracia DJ. HuR function and translational state analysis following global brain ischemia and reperfusion. Transl Stroke Res 2013; 4:589-603. [PMID: 24323414 DOI: 10.1007/s12975-013-0273-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/18/2013] [Accepted: 07/19/2013] [Indexed: 12/19/2022]
Abstract
Prolonged translation arrest in post-ischemic hippocampal CA1 pyramidal neurons precludes translation of induced stress genes and directly correlates with cell death. We evaluated the regulation of mRNAs containing adenine- and uridine-rich elements (ARE) by assessing HuR protein and hsp70 mRNA nuclear translocation, HuR polysome binding, and translation state analysis of CA1 and CA3 at 8 h of reperfusion after 10 min of global cerebral ischemia. There was no difference between CA1 and CA3 at 8 h of reperfusion in nuclear or cytoplasmic HuR protein or hsp70 mRNA, or HuR polysome association, suggesting that neither mechanism contributed to post-ischemic outcome. Translation state analysis revealed that 28 and 58 % of unique mRNAs significantly different between 8hR and NIC, in CA3 and CA1, respectively, were not polysome-bound. There was significantly greater diversity of polysome-bound mRNAs in reperfused CA3 compared to CA1, and in both regions, ARE-containing mRNAs accounted for 4-5 % of the total. These data indicate that posttranscriptional ARE-containing mRNA regulation occurs in reperfused neurons and contributes to post-ischemic outcome. Understanding the differential responses of vulnerable and resistant neurons to ischemia will contribute to the development of effective neuroprotective therapies.
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Affiliation(s)
- Jeffrey J Szymanski
- Department of Physiology, Wayne State University School of Medicine, 4116 Scott Hall, 540 East Canfield Ave, Detroit, MI, 48201, USA
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Folliculin contributes to VHL tumor suppressing activity in renal cancer through regulation of autophagy. PLoS One 2013; 8:e70030. [PMID: 23922894 PMCID: PMC3726479 DOI: 10.1371/journal.pone.0070030] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 06/14/2013] [Indexed: 12/11/2022] Open
Abstract
Von Hippel-Lindau tumor suppressor (VHL) is lost in the majority of clear cell renal cell carcinomas (ccRCC). Folliculin (FLCN) is a tumor suppressor whose function is lost in Birt-Hogg-Dubé syndrome (BHD), a disorder characterized by renal cancer of multiple histological types including clear cell carcinoma, cutaneous fibrofolliculoma, and pneumothorax. Here we explored whether there is connection between VHL and FLCN in clear cell renal carcinoma cell lines and tumors. We demonstrate that VHL regulates expression of FLCN at the mRNA and protein levels in RCC cell lines, and that FLCN protein expression is decreased in human ccRCC tumors with VHL loss, as compared with matched normal kidney tissue. Knockdown of FLCN results in increased formation of tumors by RCC cells with wild-type VHL in orthotopic xenografts in nude mice, an indication that FLCN plays a role in the tumor-suppressing activity of VHL. Interestingly, FLCN, similarly to VHL, is necessary for the activity of LC3C-mediated autophagic program that we have previously characterized as contributing to the tumor suppressing activity of VHL. The results show the existence of functional crosstalk between two major tumor suppressors in renal cancer, VHL and FLCN, converging on regulation of autophagy.
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Aparicio LA, Abella V, Valladares M, Figueroa A. Posttranscriptional regulation by RNA-binding proteins during epithelial-to-mesenchymal transition. Cell Mol Life Sci 2013; 70:4463-77. [PMID: 23715860 PMCID: PMC3827902 DOI: 10.1007/s00018-013-1379-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 05/10/2013] [Accepted: 05/16/2013] [Indexed: 12/22/2022]
Abstract
Epithelial-to-mesenchymal transition (EMT), one of the crucial steps for carcinoma cells to acquire invasive capacity, results from the disruption of cell–cell contacts and the acquisition of a motile mesenchymal phenotype. Although the transcriptional events controlling EMT have been extensively studied, in recent years, several posttranscriptional mechanisms have emerged as critical in the regulation of EMT during tumor progression. In this review, we highlight the regulation of posttranscriptional events in EMT by RNA-binding proteins (RBPs). RBPs are responsible for controlling pre-mRNA splicing, capping, and polyadenylation, as well as mRNA export, turnover, localization, and translation. We discuss the most relevant aspects of RBPs controlling the metabolism of EMT-related mRNAs, and describe the implication of novel posttranscriptional mechanisms regulating EMT in response to different signaling pathways. Novel insight into posttranscriptional regulation of EMT by RBPs is uncovering new therapeutic targets in cancer invasion and metastasis.
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Affiliation(s)
- Luis A Aparicio
- Servizo de Oncología Médica, Complejo Hospitalario Universitario A Coruña (CHUAC), SERGAS, A Coruña, Spain
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Zheng C, Baum BJ. Including the p53 ELAV-like protein-binding site in vector cassettes enhances transgene expression in rat submandibular gland. Oral Dis 2012; 18:477-84. [PMID: 22251132 DOI: 10.1111/j.1601-0825.2011.01895.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE ELAV-like proteins regulate mRNA stability and/or translation. We evaluated whether inclusion of binding sites for ELAV-like HuR proteins in vector cassettes could improve transgene expression in the salivary gland. METHODS Western blots and immunofluorescence staining were used to determine whether HuR protein was expressed in salivary cells and tissue. HuR binding sites were inserted into the pACEF1α-luc-BGH expression plasmid. Cell lines were transfected with plasmids in vitro and luciferase expression measured. Rat submandibular glands were transfected in vivo with plasmids containing ELAV-like HuR protein-binding sites. An adenoviral vector with p53 ELAV-like HuR protein-binding site was generated and also tested in vivo. Four unique 29mer HuR shRNA constructs were used in A5 cells to evaluate whether there was a specific interaction between HuR protein and the p53 HuR protein-binding site. RESULTS Salivary cells express HuR protein. Inclusion of the p53 ELAV-like HuR protein-binding site resulted in high luciferase activity in salivary cells in vitro, with similar results in vivo. In vitro shRNA data demonstrated that the high luciferase activity was mediated by the interaction between HuR protein and the p53 HuR protein-binding site. The AdEF1α-luc-p53BGH, including this binding site, mediated very high luciferase activity, ~4-fold that seen with the CMV promoter, in rat submandibular glands. CONCLUSIONS Including the p53 ELAV-like protein-binding site in transgene cassettes may enhance therapeutic vectors intended for use with salivary glands.
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Affiliation(s)
- C Zheng
- Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-1190, USA.
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Zhang J, Cho SJ, Shu L, Yan W, Guerrero T, Kent M, Skorupski K, Chen H, Chen X. Translational repression of p53 by RNPC1, a p53 target overexpressed in lymphomas. Genes Dev 2011; 25:1528-43. [PMID: 21764855 DOI: 10.1101/gad.2069311] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The p53 pathway is critical for tumor suppression, as the majority of human cancer has a faulty p53. Here, we identified RNPC1, a p53 target and a RNA-binding protein, as a critical regulator of p53 translation. We showed that ectopic expression of RNPC1 inhibited, whereas knockdown of RNPC1 increased, p53 translation under normal and stress conditions. We also showed that RNPC1 prevented cap-binding protein eIF4E from binding p53 mRNA via its C-terminal domain for physical interaction with eIF4E, and its N-terminal domain for binding p53 mRNA. Consistent with this, we found that RNPC1 directly binds to p53 5' and 3'untranslated regions (UTRs). Importantly, we showed that RNPC1 inhibits ectopic expression of p53 in a dose-dependent manner via p53 5' or 3' UTR. Moreover, we showed that loss of RNPC1 in mouse embryonic fibroblasts increased the level of p53 protein, leading to enhanced premature senescence in a p53-dependent manner. Finally, to explore the clinical relevance of our finding, we showed that RNPC1 was frequently overexpressed in dog lymphomas, most of which were accompanied by decreased expression of wild-type p53. Together, we identified a novel p53-RNPC1 autoregulatory loop, and our findings suggest that RNPC1 plays a role in tumorigenesis by repressing p53 translation.
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Affiliation(s)
- Jin Zhang
- Comparative Cancer Center, Schools of Medicine and Veterinary Medicine, University of California at Davis, USA
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The RNA-binding protein HuR stabilizes survivin mRNA in human oesophageal epithelial cells. Biochem J 2011; 437:89-96. [PMID: 21443519 DOI: 10.1042/bj20110028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Overexpression of survivin, a member of the IAP (inhibitor of apoptosis) family, has been correlated with poorer outcomes in multiple malignancies, including oesophageal cancer. The regulatory mechanisms, particularly at the post-transcriptional level, involved in survivin overexpression are not well understood. Previous work from our group has shown that the RNA-binding protein HuR (Hu antigen R), which is also overexpressed in several malignancies, stabilizes the mRNA of XIAP (X-linked IAP), another IAP family member. In the present study, we demonstrate the binding of HuR to a 288 bp fragment in the 3'-UTR (untranslated region) of survivin mRNA in human oesophageal epithelial cells. Unexpectedly, overexpression of HuR led to a decrease in survivin expression. This was associated with decreased survivin mRNA and promoter activity, suggesting a decrease in transcription. Levels of p53, a negative transcriptional regulator of survivin, increased following HuR overexpression, in conjunction with enhanced p53 mRNA stability. Silencing p53 prior to HuR overexpression resulted in increased survivin protein and mRNA stability. These results demonstrate that, in the absence of p53, HuR overexpression results in increased survivin mRNA stability and protein expression. This provides an additional explanation for the increased survivin expression observed in oesophageal cancer cells that have lost p53.
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Sermeus A, Michiels C. Reciprocal influence of the p53 and the hypoxic pathways. Cell Death Dis 2011; 2:e164. [PMID: 21614094 PMCID: PMC3122125 DOI: 10.1038/cddis.2011.48] [Citation(s) in RCA: 208] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Accepted: 04/19/2011] [Indexed: 12/17/2022]
Abstract
When cells sense a decrease in oxygen availability (hypoxia), they develop adaptive responses in order to sustain this condition and survive. If hypoxia lasts too long or is too severe, the cells eventually die. Hypoxia is also known to modulate the p53 pathway, in a manner dependent or not of HIF-1 (hypoxia-inducible factor-1), the main transcription factor activated by hypoxia. The p53 protein is a transcription factor, which is rapidly stabilised by cellular stresses and which has a major role in the cell responses to these stresses. The aim of this review is to compile what has been reported until now about the interconnection between these two important pathways. Indeed, according to the cell line, the severity and the duration of hypoxia, oxygen deficiency influences very differently p53 protein level and activity. Conversely, p53 is also described to affect HIF-1α stability, one of the two subunits of HIF-1, and HIF-1 activity. The direct and indirect interactions between HIF-1α and p53 are described as well as the involvement in this complex network of their respective ubiquitin ligases von Hippel Lindau protein and murine double minute 2. Finally, the synergistic or antagonistic effects of p53 and HIF-1 on some important cellular pathways are discussed.
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Affiliation(s)
- A Sermeus
- Laboratory of Biochemistry and Cellular Biology (URBC), NARILIS, University of Namur–FUNDP, Namur, Belgium
| | - C Michiels
- Laboratory of Biochemistry and Cellular Biology (URBC), NARILIS, University of Namur–FUNDP, Namur, Belgium
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Cooperative role of the RNA-binding proteins Hzf and HuR in p53 activation. Mol Cell Biol 2011; 31:1997-2009. [PMID: 21402775 DOI: 10.1128/mcb.01424-10] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The RNA-binding protein Hzf (hematopoietic zinc finger) plays important roles in mRNA translation in cerebellar Purkinje cells and adipocytes. We along with others have reported that the expression of the Hzf gene is transcriptionally regulated by the p53 tumor suppressor protein. We show here that Hzf regulates p53 expression in cooperation with HuR. Hzf and HuR independently interact with the 3' untranslated region (UTR) of p53 mRNA, which facilitates the cytoplasmic localization of p53 mRNA in the presence of the ARF tumor suppressor protein. In the absence of Hzf and HuR, p53 induction by p19(ARF) is significantly attenuated, and the cells consequently acquire resistance to p19(ARF). Thus, these findings demonstrate that in addition to Mdm2 inhibition, p19(ARF) increases the concentration of p53 through posttranscriptional control of p53 mRNA and suggest critical roles for the RNA-binding proteins Hzf and HuR in p53 induction.
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39
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Vilborg A, Bersani C, Wilhelm MT, Wiman KG. The p53 target Wig-1: a regulator of mRNA stability and stem cell fate? Cell Death Differ 2011; 18:1434-40. [PMID: 21394102 DOI: 10.1038/cdd.2011.20] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Wig-1 is a transcriptional target of the tumor suppressor p53 and encodes an unusual zinc-finger protein involved in post-transcriptional gene regulation. Wig-1 is expressed in all cell types investigated so far, with the highest levels in the brain, and is enriched in stem cells as compared with more differentiated cells of the same lineage. Wig-1 binds to both long double-stranded (ds) RNA and short microRNA-like dsRNA. We have shown that Wig-1 acts in a positive feedback loop that stabilizes p53 mRNA through an AU-rich element (ARE) in the p53 3'untranslated region. Our preliminary data indicate a more general effect of Wig-1 on ARE-containing mRNA. Here we shall summarize current knowledge about Wig-1 and discuss possible implications on p53 function and other cellular processes.
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Affiliation(s)
- A Vilborg
- Karolinska Institutet, Department of Oncology-Pathology, Cancer Center Karolinska, Stockholm, Sweden
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40
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Zheltukhin AO, Chumakov PM. Constitutive and induced functions of the p53 gene. BIOCHEMISTRY (MOSCOW) 2011; 75:1692-721. [DOI: 10.1134/s0006297910130110] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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41
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Ronkainen H, Vaarala MH, Hirvikoski P, Ristimäki A. HuR expression is a marker of poor prognosis in renal cell carcinoma. Tumour Biol 2010; 32:481-7. [PMID: 21161467 DOI: 10.1007/s13277-010-0141-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2010] [Accepted: 12/01/2010] [Indexed: 11/24/2022] Open
Abstract
The HuR protein is a nucleocytoplasmic protein which plays an important role in the regulation of mRNA stability, and dysregulation of its expression has been linked to carcinogenesis. We studied 152 patients with primary renal cell carcinoma (RCC) who underwent surgery for the removal of kidney tumours between 1990 and 1999. The mean follow-up was 90 months. The expression of HuR and cyclooxygenase-2 (COX-2) was determined by immunohistochemistry using monoclonal antibodies. The immunostaining results were associated with patient age, clinical stage, Fuhrman grade and patient outcome. Cytoplasmic expression of HuR and COX-2 was positive in 37 (25%) and 22 (15%) of the tumours, respectively. The expression of HuR was associated with stage. The expression of COX-2 was associated with stage and nuclear grade. The RCC-specific survival was reduced in patients whose tumours expressed HuR or COX-2. The hazard ratio (HR) of patients with HuR-expressing tumours was 2.18 (95% confidence interval (CI), 1.16-4.09; p = 0.015) and the HR of patients with COX-2-expressing tumours was 2.29 (95% CI, 1.15-4.54; p = 0.018). In the Cox regression analysis the only independent prognostic factor was stage (p < 0.001). Treatment of an RCC cell line (769-P) with HuR-targeted small interfering RNA resulted in the reduced expression of HuR and COX-2. We conclude that cytoplasmic HuR expression is associated with reduced RCC-specific survival. The HuR protein regulates the expression of COX-2 in RCC cells, which is one potential mechanism of action for the HuR-associated aggressive behaviour of RCC.
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Affiliation(s)
- Hanna Ronkainen
- Department of Surgery, Oulu University Hospital, PO Box 21, 90029 OYS, Oulu, Finland
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42
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Ribosomal protein S6 is highly expressed in non-Hodgkin lymphoma and associates with mRNA containing a 5' terminal oligopyrimidine tract. Oncogene 2010; 30:1531-41. [PMID: 21102526 DOI: 10.1038/onc.2010.533] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The molecular mechanism(s) linking tumorigenesis and morphological alterations in the nucleolus are presently coming into focus. The nucleolus is the cellular organelle in which the formation of ribosomal subunits occurs. Ribosomal biogenesis occurs through the transcription of ribosomal RNA (rRNA), rRNA processing and production of ribosomal proteins. An error in any of these processes may lead to deregulated cellular translation, evident in multiple cancers and 'ribosomopathies'. Deregulated protein synthesis may be achieved through the overexpression of ribosomal proteins as seen in primary leukemic blasts with elevated levels of ribosomal proteins S11 and S14. In this study, we demonstrate that ribosomal protein S6 (RPS6) is highly expressed in primary diffuse large B-cell lymphoma (DLBCL) samples. Genetic modulation of RPS6 protein levels with specifically targeted short hairpin RNA (shRNA) lentiviruses led to a decrease in the actively proliferating population of cells compared with control shRNA. Low-dose rapamycin treatments have been shown to affect the translation of 5' terminal oligopyrimidine (5' TOP) tract mRNA, which encodes the translational machinery, implicating RPS6 in 5' TOP translation. Recently, it was shown that disruption of 40S ribosomal biogenesis through specific small inhibitory RNA knockdown of RPS6 defined RPS6 as a critical regulator of 5' TOP translation. For the first time, we show that RPS6 associates with multiple mRNAs containing a 5' TOP tract. These findings expand our understanding of the mechanism(s) involved in ribosomal biogenesis and deregulated protein synthesis in DLBCL.
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43
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Stumpo DJ, Lai WS, Blackshear PJ. Inflammation: cytokines and RNA-based regulation. WILEY INTERDISCIPLINARY REVIEWS-RNA 2010; 1:60-80. [PMID: 21956907 DOI: 10.1002/wrna.1] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The outcome of an inflammatory response depends upon the coordinated regulation of a variety of both pro-inflammatory and anti-inflammatory cytokines and other proteins. Regulation of these inflammation mediators can occur at multiple levels, including transcription, mRNA translation, post-translational modifications, and mRNA degradation. Post-transcriptional regulation has been shown to play an important role in controlling the expression of these mediators, allowing for normal initiation and resolution of the inflammatory response. Many inflammatory mediators have unstable mRNAs due, in part, to the presence of AU-rich elements in their 3'-untranslated regions. Increasing numbers of RNA-binding proteins have been identified that can bind to these AU-rich elements and then regulate the stability and/or translation of the mRNA. This review summarizes current knowledge about the role of several RNA-binding proteins that act through AU-rich elements to post-transcriptionally regulate the biosynthesis of proteins involved in inflammation.
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Affiliation(s)
- Deborah J Stumpo
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA
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Mazumder B, Li X, Barik S. Translation control: a multifaceted regulator of inflammatory response. THE JOURNAL OF IMMUNOLOGY 2010; 184:3311-9. [PMID: 20304832 DOI: 10.4049/jimmunol.0903778] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A robust innate immune response is essential to the protection of all vertebrates from infection, but it often comes with the price tag of acute inflammation. If unchecked, a runaway inflammatory response can cause significant tissue damage, resulting in myriad disorders, such as dermatitis, toxic shock, cardiovascular disease, acute pelvic and arthritic inflammatory diseases, and various infections. To prevent such pathologies, cells have evolved mechanisms to rapidly and specifically shut off these beneficial inflammatory activities before they become detrimental. Our review of recent literature, including our own work, reveals that the most dominant and common mechanism is translational silencing, in which specific regulatory proteins or complexes are recruited to cis-acting RNA structures in the untranslated regions of single or multiple mRNAs that code for the inflammatory protein(s). Enhancement of the silencing function may constitute a novel pharmacological approach to prevent immunity-related inflammation.
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Affiliation(s)
- Barsanjit Mazumder
- Department of Biology, Geology and Environmental Science, Center for Gene Regulation in Health and Disease, College of Science, Cleveland State University, Cleveland, OH 44115, USA.
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45
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Vilborg A, Wilhelm MT, Wiman KG. Regulation of tumor suppressor p53 at the RNA level. J Mol Med (Berl) 2010; 88:645-52. [PMID: 20306257 DOI: 10.1007/s00109-010-0609-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 02/22/2010] [Accepted: 02/24/2010] [Indexed: 01/07/2023]
Abstract
p53 is a key tumor suppressor that triggers cell cycle arrest, senescence, or apoptosis in response to cellular stress. Frequent p53 mutation in human tumors allows survival, sustained growth, and tumor progression. p53 is expressed at low levels under normal conditions, due to rapid protein turnover. Stress signaling induces p53 protein stabilization through phosphorylation and other post-translational modifications. However, recent studies have demonstrated critical regulation of p53 at the mRNA level, mediated via both the 5'UTR and the 3'UTR and affecting both the stability and the translation efficiency of the p53 mRNA. Both proteins and microRNAs have been implicated in such regulation. The p53 target gene Wig-1 encodes a zinc finger protein that binds to double-stranded RNA and enhances p53 mRNA stability by binding to the 3'UTR in a positive feedback loop. Here, we shall summarize current knowledge about regulation of the p53 mRNA and discuss possible implications for cancer therapy.
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Affiliation(s)
- Anna Vilborg
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
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Kim MJ, Park IJ, Yun H, Kang I, Choe W, Kim SS, Ha J. AMP-activated protein kinase antagonizes pro-apoptotic extracellular signal-regulated kinase activation by inducing dual-specificity protein phosphatases in response to glucose deprivation in HCT116 carcinoma. J Biol Chem 2010; 285:14617-27. [PMID: 20220132 DOI: 10.1074/jbc.m109.085456] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Mitogen-activated protein kinase (MAPK) pathways are involved in the regulation of cellular responses, including cell proliferation, differentiation, cell growth, and apoptosis. Because these responses are tightly related to cellular energy level, AMP-activated protein kinase (AMPK), which plays an essential role in energy homeostasis, has emerged as another key regulator. In the present study, we demonstrate a novel signal network between AMPK and MAPK in HCT116 human colon carcinoma. Glucose deprivation activated AMPK and three MAPK subfamilies, extracellular signal-regulated kinase (ERK), c-Jun NH(2)-terminal kinase (JNK), and p38 MAPK. Under these conditions, inhibition of endogenous AMPK by expressing a dominant-negative form significantly potentiated ERK activation, indicating that glucose deprivation-induced AMPK is specifically antagonizing ERK activity in HCT116 cells. Moreover, we provide novel evidence that AMPK activity is critical for p53-dependent expression of dual-specificity phosphatase (DUSP) 1 & 2, which are negative regulators of ERK. Notably, ERK exhibits pro-apoptotic effects in HCT116 cells under glucose deprivation. Collectively, our data suggest that AMPK protects HCT116 cancer cells from glucose deprivation, in part, via inducing DUSPs, which suppresses pro-apoptotic ERK, further implying that a signal network between AMPK and ERK is a critical regulatory point in coupling the energy status of the cell to the regulation of cell survival.
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Affiliation(s)
- Min-Jung Kim
- Department of Biochemistry and Molecular Biology, Medical Research Center and Biomedical Science Institute, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea
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Danilin S, Sourbier C, Thomas L, Lindner V, Rothhut S, Dormoy V, Helwig JJ, Jacqmin D, Lang H, Massfelder T. Role of the RNA-binding protein HuR in human renal cell carcinoma. Carcinogenesis 2010; 31:1018-26. [PMID: 20219773 DOI: 10.1093/carcin/bgq052] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Human conventional renal cell carcinoma (CRCC) remains resistant to therapy. The RNA-binding protein HuR regulates the stability and/or translation of multiple messenger RNAs involved in malignant transformation. In this study, we aimed to evaluate the potential role of HuR in this pathology. Using seven human CRCC cell lines expressing or not the von Hippel-Lindau (VHL) tumor suppressor gene as well as 15 normal/renal cell carcinoma tumor pairs, we showed that HuR is overexpressed in all tumors independently of the VHL status. Futhermore, HuR cytoplasmic presence appears to be more common in early tumor stages, suggesting a role in tumor promotion. We then assessed the effect of HuR knockdown using small interfering RNA in cultured cell and in tumor-bearing mice. Both in vitro and in vivo, we observed that cell growth was inhibited by 60% and that this effect was obtained through an inhibition of cell proliferation and an induction of cell apoptosis. Finally, we found that expression of vascular endothelium growth factor, tumor growth factor-beta and of the hypoxia-induced transcription factor-2alpha as well as the constitutive activation of the oncogenic phosphoinositide 3-kinase/Akt, nuclear factor-kappaB and mitogen-activated protein kinase pathways were decreased in HuR-depleted cells and tumors. All these results suggest a pivotal role for HuR in human CRCC.
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Affiliation(s)
- Sabrina Danilin
- Institut National de la Sante et de la Recherche Medicale U682, Section of Renal Cancer and Physiopathology, University de Strasbourg, School of Medicine, Strasbourg, 67085 France
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48
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Bae H, Gray JS, Li M, Vines L, Kim J, Pestka JJ. Hematopoietic cell kinase associates with the 40S ribosomal subunit and mediates the ribotoxic stress response to deoxynivalenol in mononuclear phagocytes. Toxicol Sci 2010; 115:444-52. [PMID: 20181660 DOI: 10.1093/toxsci/kfq055] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The trichothecene deoxynivalenol (DON) binds to eukaryotic ribosomes and triggers p38-driven proinflammatory gene expression in the macrophage-a response that is dependent on both double-stranded RNA-activated protein kinase (PKR) and hematopoietic cell kinase (Hck). Here we elucidated critical linkages that exist among the ribosome and these kinases during the course of DON-induced ribotoxic stress in mononuclear phagocytes. Similar to PKR inhibitors, Hck inhibitor 4-amino-5-(4-chlorophenyl)-7-(t-butyl)pyrazolo[3,4-d]pyramidine (PP2) suppressed p38 activation and p38-driven interleukin 8 (IL-8) expression in the U937 human monocyte cell line. U937 cells stably transfected with a PKR antisense vector (U9K-A1) displayed marked reduction of DON-induced p38 activation and IL-8 expression as compared to cells transfected with empty vector (U9K-C2), with both responses being completely ablated by PP2. Western analysis of sucrose density gradient fractions revealed that PKR and Hck interacted with the 40S ribosomal subunit in U9K-C2 but not U9K-A1 cells. Subsequent transfection and immunoprecipitation studies with HeLa cells indicated that Hck interacted with ribosomal protein S3. Consistent with U937 cells, DON induced p38 association with the ribosome and phosphorylation in peritoneal macrophages from wild-type but not PKR-deficient mice. DON-induced phosphorylation of ribosome-associated Hck in RAW 264.7 murine macrophages was also suppressed by 2-aminopurine (2-AP). Both 2-AP and PP2 inhibited DON-induced phosphorylation of p38 as well as two kinases, apoptosis signal-regulating kinase 1 and mitogen-activated protein kinase 3/6, known to be upstream of p38. Taken together, PKR and Hck were critical for DON-induced ribosomal recruitment of p38, its subsequent phosphorylation, and, ultimately, p38-driven proinflammatory cytokine expression.
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Affiliation(s)
- Heekyong Bae
- Center for Integrative Toxicology, Michigan State University, East Lansing, Michigan 48824-1224, USA
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49
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Gardner LB. Nonsense-mediated RNA decay regulation by cellular stress: implications for tumorigenesis. Mol Cancer Res 2010; 8:295-308. [PMID: 20179151 DOI: 10.1158/1541-7786.mcr-09-0502] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Nonsense-mediated RNA decay (NMD) has long been viewed as an important constitutive mechanism to rapidly eliminate mutated mRNAs. More recently, it has been appreciated that NMD also degrades multiple nonmutated transcripts and that NMD can be regulated by wide variety of cellular stresses. Many of the stresses that inhibit NMD, including cellular hypoxia and amino acid deprivation, are experienced in cells exposed to hostile microenvironments, and several NMD-targeted transcripts promote cellular adaptation in response to these environmental stresses. Because adaptation to the microenvironment is crucial in tumorigenesis, and because NMD targets many mutated tumor suppressor gene transcripts, the regulation of NMD may have particularly important implications in cancer. This review briefly outlines the mechanisms by which transcripts are identified and targeted by NMD and reviews the evidence showing that NMD is a regulated process that can dynamically alter gene expression. Although much of the focus in NMD research has been in identifying the proteins that play a role in NMD and identifying NMD-targeted transcripts, recent data about the potential functional significance of NMD regulation, including the stabilization of alternatively spliced mRNA isoforms, the validation of mRNAs as bona fide NMD targets, and the role of NMD in tumorigenesis, are explored.
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Affiliation(s)
- Lawrence B Gardner
- Division of Hematology, Department of Medicine, New York University School of Medicine, New York, NY 10016, USA.
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50
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Hollstein M, Hainaut P. Massively regulated genes: the example of TP53. J Pathol 2010; 220:164-73. [PMID: 19918835 DOI: 10.1002/path.2637] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Intensive study of the TP53 gene over the last three decades has revealed a highly complex network of factors that regulate its performance. The gene has several promoters, alternative splicing occurs and there are alternative translation initiation sites. Up to 10 p53 isoforms have been identified. At the post-translational level, p53 activity depends on its quantity in the cell and on qualitative changes in its structure, intracellular localization, DNA-binding activity and interactions with other proteins. Both accumulation and activation are regulated by an intricate pattern of post-translational modifications, including phosphorylation, acetylation, ubiquitination, sumoylation, neddylation, methylation and glycosylation. The Mdm2 protein, a negative regulator of p53, is the most important determinant of p53 abundance and subcellular localization. Enzymes that post-translationally modify p53 by phosphorylation, methylation and acetylation fine-tune p53 binding to recognition sequences in DNA and p53 interactions with transcription cofactors at promoters of target genes, thereby exerting a discriminatory role in p53 function. This multitude of parameters determining expression, modification, accumulation and localization of p53 proteins may explain how a single gene can display an extensive repertoire of activities. Presumably this is needed, because the p53 protein can have such profound consequences for a cell.
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