1
|
Zhang Y, Song Z, Wu R, Kong X, Zhang H, Li S, Gong X, Gong S, Cheng J, Yuan F, Wu H, Wang S, Yuan Z. PRRC2B modulates oligodendrocyte progenitor cell development and myelination by stabilizing Sox2 mRNA. Cell Rep 2024; 43:113930. [PMID: 38507412 DOI: 10.1016/j.celrep.2024.113930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 01/13/2024] [Accepted: 02/21/2024] [Indexed: 03/22/2024] Open
Abstract
Oligodendrocyte progenitor cells (OPCs) differentiate into myelin-producing cells and modulate neuronal activity. Defects in OPC development are associated with neurological diseases. N6-methyladenosine (m6A) contributes to neural development; however, the mechanism by which m6A regulates OPC development remains unclear. Here, we demonstrate that PRRC2B is an m6A reader that regulates OPC development and myelination. Nestin-Cre-mediated Prrc2b deletion affects neural stem cell self-renewal and glial differentiation. Moreover, the oligodendroglia lineage-specific deletion of Prrc2b reduces the numbers of OPCs and oligodendrocytes, causing hypomyelination and impaired motor coordination. Integrative methylated RNA immunoprecipitation sequencing, RNA sequencing, and RNA immunoprecipitation sequencing analyses identify Sox2 as the target of PRRC2B. Notably, PRRC2B, displaying separate and cooperative functions with PRRC2A, stabilizes mRNA by binding to m6A motifs in the coding sequence and 3' UTR of Sox2. In summary, we identify the posttranscriptional regulation of PRRC2B in OPC development, extending the understanding of PRRC2 family proteins and providing a therapeutic target for myelin-related disorders.
Collapse
Affiliation(s)
- Ying Zhang
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Zhihong Song
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Rong Wu
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xiangxi Kong
- Jiangsu Province Key Laboratory of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application Technology, Xuzhou Medical University, Xuzhou 221004, China
| | - Hongye Zhang
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Shuoshuo Li
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China; School of Life Science, Beijing University of Chinese Medicine, Beijing 100029, China
| | - Xuanwei Gong
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Shenghui Gong
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Jinbo Cheng
- Center on Translational Neuroscience, College of Life and Environmental Science, Minzu University of China, Beijing 100081, China; Key Laboratory of Neurology (Hebei Medical University), Ministry of Education, Shijiazhuang 050000, China
| | - Fang Yuan
- Department of Oncology, The Fifth Medical Center, Chinese PLA General Hospital, Beijing 100071, China
| | - Haitao Wu
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Shukun Wang
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China.
| | - Zengqiang Yuan
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China.
| |
Collapse
|
2
|
Muazzen Z, Moghrabi W, Bakheet T, Mahmoud L, Al-Saif M, Khabar KSA, Hitti EG. Global analysis of the abundance of AU-rich mRNAs in response to glucocorticoid treatment. Sci Rep 2024; 14:913. [PMID: 38195703 PMCID: PMC10776588 DOI: 10.1038/s41598-024-51301-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 01/02/2024] [Indexed: 01/11/2024] Open
Abstract
Glucocorticoids (GC) like dexamethasone (Dex) are potent anti-inflammatory agents with diverse cellular functions including the potentiation of the activity of AU-rich elements (AREs). AREs are cis-acting instability sequence elements located in the 3'UTRs of many inflammatory mediator mRNAs. Here, available RNA-seq data were used to investigate the effect of GCs on the ARE-mRNA-transcriptome. At a global scale, ARE-mRNAs had a tendency to be downregulated after GC-treatment of the A549 lung cancer cell-line, but with notable cases of upregulation. mRNA stability experiments indicated that not only the downregulated, but also the upregulated ARE-mRNAs are destabilized by Dex-treatment. Several of the most upregulated ARE-mRNAs code for anti-inflammatory mediators including the established GC targets DUSP1 and ZFP36; both code for proteins that target ARE-containing mRNAs for destruction. GCs are widely used in the treatment of COVID-19 patients; we show that ARE-mRNAs are more likely to regulate in opposite directions between Dex-treatment and SARS-CoV-2 infections compared to non-ARE mRNAs. The effect of GC treatment on ARE-mRNA abundance was also investigated in blood monocytes of COVID-19 patients. The results were heterogeneous; however, in agreement with in vitro observations, ZFP36 and DUSP1 were often amongst the most differentially expressed mRNAs. The results of this study propose a universal destabilization of ARE-mRNAs by GCs, but a diverse overall outcome in vitro likely due to induced transcription or due to the heterogeneity of COVID-19 patient's responses in vivo.
Collapse
Affiliation(s)
- Zeyad Muazzen
- Molecular BioMedicine Department, Research and Innovation, King Faisal Specialist Hospital and Research Centre, 11211, Riyadh, Saudi Arabia
| | - Walid Moghrabi
- Molecular BioMedicine Department, Research and Innovation, King Faisal Specialist Hospital and Research Centre, 11211, Riyadh, Saudi Arabia
| | - Tala Bakheet
- Molecular BioMedicine Department, Research and Innovation, King Faisal Specialist Hospital and Research Centre, 11211, Riyadh, Saudi Arabia
| | - Linah Mahmoud
- Molecular BioMedicine Department, Research and Innovation, King Faisal Specialist Hospital and Research Centre, 11211, Riyadh, Saudi Arabia
| | - Maher Al-Saif
- Molecular BioMedicine Department, Research and Innovation, King Faisal Specialist Hospital and Research Centre, 11211, Riyadh, Saudi Arabia
| | - Khalid S A Khabar
- Molecular BioMedicine Department, Research and Innovation, King Faisal Specialist Hospital and Research Centre, 11211, Riyadh, Saudi Arabia
| | - Edward G Hitti
- Molecular BioMedicine Department, Research and Innovation, King Faisal Specialist Hospital and Research Centre, 11211, Riyadh, Saudi Arabia.
| |
Collapse
|
3
|
Salvato I, Ricciardi L, Nucera F, Nigro A, Dal Col J, Monaco F, Caramori G, Stellato C. RNA-Binding Proteins as a Molecular Link between COPD and Lung Cancer. COPD 2023; 20:18-30. [PMID: 36655862 DOI: 10.1080/15412555.2022.2107500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) represents an independent risk factor for lung cancer development. Accelerated cell senescence, induced by oxidative stress and inflammation, is a common pathogenic determinant of both COPD and lung cancer. The post transcriptional regulation of genes involved in these processes is finely regulated by RNA-binding proteins (RBPs), which regulate mRNA turnover, subcellular localization, splicing and translation. Multiple pro-inflammatory mediators (including cytokines, chemokines, proteins, growth factors and others), responsible of lung microenvironment alteration, are regulated by RBPs. Several mouse models have shown the implication of RBPs in multiple mechanisms that sustain chronic inflammation and neoplastic transformation. However, further studies are required to clarify the role of RBPs in the pathogenic mechanisms shared by lung cancer and COPD, in order to identify novel biomarkers and therapeutic targets. This review will therefore focus on the studies collectively indicating the role of RBPs in oxidative stress and chronic inflammation as common pathogenic mechanisms shared by lung cancer and COPD.
Collapse
Affiliation(s)
- Ilaria Salvato
- Pneumologia, Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali (BIOMORF), Università degli Studi di Messina, Italy
| | - Luca Ricciardi
- Pneumologia, Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali (BIOMORF), Università degli Studi di Messina, Italy
| | - Francesco Nucera
- Pneumologia, Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali (BIOMORF), Università degli Studi di Messina, Italy
| | - Annunziata Nigro
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Jessica Dal Col
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| | - Francesco Monaco
- Chirurgia Toracica, Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali (BIOMORF), Università degli Studi di Messina, Italy
| | - Gaetano Caramori
- Pneumologia, Dipartimento di Scienze Biomediche, Odontoiatriche e delle Immagini Morfologiche e Funzionali (BIOMORF), Università degli Studi di Messina, Italy
| | - Cristiana Stellato
- Department of Medicine, Surgery and Dentistry "Scuola Medica Salernitana", University of Salerno, Salerno, Italy
| |
Collapse
|
4
|
Schultz CW, Zhang Y, Elmeskini R, Zimmermann A, Fu H, Murai Y, Wangsa D, Kumar S, Takahashi N, Atkinson D, Saha LK, Lee C, Elenbaas B, Desai P, Sebastian R, Sharma AK, Abel M, Schroeder B, Krishnamurthy M, Kumar R, Roper N, Aladjem M, Zenke FT, Ohler ZW, Pommier Y, Thomas A. ATR inhibition augments the efficacy of lurbinectedin in small-cell lung cancer. EMBO Mol Med 2023; 15:e17313. [PMID: 37491889 PMCID: PMC10405061 DOI: 10.15252/emmm.202217313] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 06/12/2023] [Accepted: 06/19/2023] [Indexed: 07/27/2023] Open
Abstract
Small-cell lung cancer (SCLC) is the most lethal type of lung cancer. Specifically, MYC-driven non-neuroendocrine SCLC is particularly resistant to standard therapies. Lurbinectedin was recently approved for the treatment of relapsed SCLC, but combinatorial approaches are needed to increase the depth and duration of responses to lurbinectedin. Using high-throughput screens, we found inhibitors of ataxia telangiectasia mutated and rad3 related (ATR) as the most effective agents for augmenting lurbinectedin efficacy. First-in-class ATR inhibitor berzosertib synergized with lurbinectedin in multiple SCLC cell lines, organoid, and in vivo models. Mechanistically, ATR inhibition abrogated S-phase arrest induced by lurbinectedin and forced cell cycle progression causing mitotic catastrophe and cell death. High CDKN1A/p21 expression was associated with decreased synergy due to G1 arrest, while increased levels of ERCC5/XPG were predictive of increased combination efficacy. Importantly, MYC-driven non-neuroendocrine tumors which are resistant to first-line therapies show reduced CDKN1A/p21 expression and increased ERCC5/XPG indicating they are primed for response to lurbinectedin-berzosertib combination. The combination is being assessed in a clinical trial NCT04802174.
Collapse
Affiliation(s)
- Christopher W Schultz
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Yang Zhang
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Rajaa Elmeskini
- Center for Advanced Preclinical Research, Leidos Biomedical Research, IncFrederick National Laboratory for Cancer ResearchFrederickMDUSA
| | - Astrid Zimmermann
- Translational Innovation Platform OncologyMerck KGaA, Biopharma R&DDarmstadtGermany
| | - Haiqing Fu
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Yasuhisa Murai
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Darawalee Wangsa
- Genetics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Suresh Kumar
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Nobuyuki Takahashi
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
- Medical Oncology BranchNational Center for Global Health and MedicineTokyoJapan
| | - Devon Atkinson
- Center for Advanced Preclinical Research, Leidos Biomedical Research, IncFrederick National Laboratory for Cancer ResearchFrederickMDUSA
| | - Liton Kumar Saha
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Chien‐Fei Lee
- Translational Innovation Platform OncologyEMD Serono Research and Development Institute Inc., Biopharma R&DBillericaMAUSA
| | - Brian Elenbaas
- Translational Innovation Platform OncologyEMD Serono Research and Development Institute Inc., Biopharma R&DBillericaMAUSA
| | - Parth Desai
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Robin Sebastian
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Ajit Kumar Sharma
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Melissa Abel
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Brett Schroeder
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Manan Krishnamurthy
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Rajesh Kumar
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Nitin Roper
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Mirit Aladjem
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Frank T Zenke
- Translational Innovation Platform OncologyMerck KGaA, Biopharma R&DDarmstadtGermany
| | - Zoe Weaver Ohler
- Center for Advanced Preclinical Research, Leidos Biomedical Research, IncFrederick National Laboratory for Cancer ResearchFrederickMDUSA
| | - Yves Pommier
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| | - Anish Thomas
- Developmental Therapeutics Branch, Center for Cancer ResearchNational Cancer Institute, National Institutes of HealthBethesdaMDUSA
| |
Collapse
|
5
|
The human ion channel TRPM2 modulates cell survival in neuroblastoma through E2F1 and FOXM1. Sci Rep 2022; 12:6311. [PMID: 35428820 PMCID: PMC9012789 DOI: 10.1038/s41598-022-10385-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 04/05/2022] [Indexed: 12/15/2022] Open
Abstract
Transient receptor potential channel melastatin 2 (TRPM2) is highly expressed in cancer and has an essential function in preserving viability through maintenance of mitochondrial function and antioxidant response. Here, the role of TRPM2 in cell survival was examined in neuroblastoma cells with TRPM2 deletion with CRISPR technology. Viability was significantly decreased in TRPM2 knockout after doxorubicin treatment. RNA sequence analysis and RT-qPCR revealed reduced RNAs encoding master transcription regulators FOXM1 and E2F1/2 and downstream cell cycle targets including Cyclin B1, CDK1, PLK1, and CKS1. CHIP analysis demonstrated decreased FOXM1 binding to their promoters. Western blotting confirmed decreased expression, and increased expression of CDK inhibitor p21, a CKS1 target. In cells with TRPM2 deletion, cell cycle progression to S and G2/M phases was reduced after treatment with doxorubicin. RNA sequencing also identified decreased DNA repair proteins in cells with TRPM2 deletion after doxorubicin treatment, and DNA damage was increased. Wild type TRPM2, but not Ca2+-impermeable mutant E960D, restored live cell number and reconstituted expression of E2F1, FOXM1, and cell cycle/DNA repair proteins. FOXM1 expression alone restored viability. TRPM2 is a potential therapeutic target to reduce tumor proliferation and increase doxorubicin sensitivity through modulation of FOXM1, E2F1, and cell cycle/DNA repair proteins.
Collapse
|
6
|
Serna-Salas SA, Arroyave-Ospina JC, Zhang M, Damba T, Buist-Homan M, Muñoz-Ortega MH, Ventura-Juárez J, Moshage H. α-1 Adrenergic receptor antagonist doxazosin reverses hepatic stellate cells activation via induction of senescence. Mech Ageing Dev 2021; 201:111617. [PMID: 34958827 DOI: 10.1016/j.mad.2021.111617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/06/2021] [Accepted: 12/21/2021] [Indexed: 12/12/2022]
Abstract
BACKGROUND Activated hepatic stellate cells (aHSCs) are the main effector cells during liver fibrogenesis. α-1 adrenergic antagonist doxazosin (DX) was shown to be anti-fibrotic in an in vivo model of liver fibrosis (LF), but the mechanism remains to be elucidated. Recent studies suggest that reversion of LF can be achieved by inducing cellular senescence characterized by irreversible cell-cycle arrest and acquisition of the senescence-associated secretory phenotype (SASP). AIM To elucidate the mechanism of the anti-fibrotic effect of DX and determine whether it induces senescence. METHODS Primary culture-activated rat HSCs were used. mRNA and protein expression were measured by qPCR and Western blot, respectively. Cell proliferation was assessed by BrdU incorporation and xCelligence analysis. TGF-β was used for maximal HSC activation. Norepinephrine (NE), PMA and m-3M3FBS were used to activate alpha-1 adrenergic signaling. RESULTS Expression of Col1α1 was significantly decreased by DX (10 µmol/L) at mRNA (-30 %) and protein level (-50 %) in TGF-β treated aHSCs. DX significantly reduced aHSCs proliferation and increased expression of senescence and SASP markers. PMA and m-3M3FBS reversed the effect of DX on senescence markers. CONCLUSION Doxazosin reverses the fibrogenic phenotype of aHSCs and induces the senescence phenotype.
Collapse
Affiliation(s)
- Sandra A Serna-Salas
- Dept. Morphology, Autonomous University of Aguascalientes, Aguascalientes, Mexico; Dept. Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Johanna C Arroyave-Ospina
- Dept. Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Mengfan Zhang
- Dept. Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Turtushikh Damba
- Dept. Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Manon Buist-Homan
- Dept. Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Dept. Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | | | | | - Han Moshage
- Dept. Gastroenterology and Hepatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands; Dept. Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| |
Collapse
|
7
|
Hepatocyte-Specific Deficiency of BAP31 Amplified Acetaminophen-Induced Hepatotoxicity via Attenuating Nrf2 Signaling Activation in Mice. Int J Mol Sci 2021; 22:ijms221910788. [PMID: 34639126 PMCID: PMC8509202 DOI: 10.3390/ijms221910788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/28/2021] [Accepted: 09/30/2021] [Indexed: 01/18/2023] Open
Abstract
Liver-specific deficiency of B-cell receptor-associated protein 31 knockout mice (BAP31-LKO) and the littermates were injected with acetaminophen (APAP), markers of liver injury, and the potential molecular mechanisms were determined. In response to APAP overdose, serum aspartate aminotransferase and alanine aminotransferase levels were increased in BAP31-LKO mice than in wild-type controls, accompanied by enhanced liver necrosis. APAP-induced apoptosis and mortality were increased. Hepatic glutathione was decreased (1.60 ± 0.31 μmol/g tissue in WT mice vs. 0.85 ± 0.14 μmol/g tissue in BAP31-LKO mice at 6 h, p < 0.05), along with reduced glutathione reductase activity and superoxide dismutase; while malondialdehyde was significantly induced (0.41 ± 0.03 nmol/mg tissue in WT mice vs. 0.50 ± 0.05 nmol/mg tissue in BAP31-LKO mice for 6 h, p < 0.05). JNK signaling activation and APAP-induced hepatic inflammation were increased in BAP31-LKO mice. The mechanism research revealed that BAP31-deficiency decreased Nrf2 mRNA stability (half-life of Nrf2 mRNA decreased from ~1.3 h to ~40 min) and miR-223 expression, led to reduced nuclear factor erythroid 2-related factor 2 (Nrf2) signaling activation and antioxidant genes induction. BAP31-deficiency decreased mitochondrial membrane potentials, reduced mitochondria-related genes expression, and resulted in mitochondrial dysfunction in the liver. Conclusions: BAP31-deficiency reduced the antioxidant response and Nrf2 signaling activation via reducing Nrf2 mRNA stabilization, enhanced JNK signaling activation, hepatic inflammation, and apoptosis, amplified APAP-induced hepatotoxicity in mice.
Collapse
|
8
|
Antitumour Activity of the Ribonuclease Binase from Bacillus pumilus in the RLS 40 Tumour Model Is Associated with the Reorganisation of the miRNA Network and Reversion of Cancer-Related Cascades to Normal Functioning. Biomolecules 2020; 10:biom10111509. [PMID: 33147876 PMCID: PMC7692507 DOI: 10.3390/biom10111509] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 10/30/2020] [Accepted: 10/30/2020] [Indexed: 12/21/2022] Open
Abstract
The important role of miRNA in cell proliferation and differentiation has raised interest in exogenous ribonucleases (RNases) as tools to control tumour-associated intracellular and extracellular miRNAs. In this work, we evaluated the effects of the RNase binase from Bacillus pumilus on small non-coding regulatory RNAs in the context of mouse RLS40 lymphosarcoma inhibition. In vitro binase exhibited cytotoxicity towards RLS40 cells via apoptosis induction through caspase-3/caspase-7 activation and decreased the levels of miR-21a, let-7g, miR-31 and miR-155. Intraperitoneal injections of binase in RLS40-bearing mice resulted in the retardation of primary tumour growth by up to 60% and inhibition of metastasis in the liver by up to 86%, with a decrease in reactive inflammatory infiltration and mitosis in tumour tissue. In the blood serum of binase-treated mice, decreases in the levels of most studied miRNAs were observed, excluding let-7g, while in tumour tissue, the levels of oncomirs miR-21, miR-10b, miR-31 and miR-155, and the oncosuppressor let-7g, were upregulated. Analysis of binase-susceptible miRNAs and their regulatory networks showed that the main modulated events were transcription and translation control, the cell cycle, cell proliferation, adhesion and invasion, apoptosis and autophagy, as well as some other tumour-related cascades, with an impact on the observed antitumour effects.
Collapse
|
9
|
Anerillas C, Abdelmohsen K, Gorospe M. Regulation of senescence traits by MAPKs. GeroScience 2020; 42:397-408. [PMID: 32300964 PMCID: PMC7205942 DOI: 10.1007/s11357-020-00183-3] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 03/10/2020] [Indexed: 01/10/2023] Open
Abstract
A phenotype of indefinite growth arrest acquired in response to sublethal damage, cellular senescence affects normal aging and age-related disease. Mitogen-activated protein kinases (MAPKs) are capable of sensing changes in cellular conditions, and in turn elicit adaptive responses including cell senescence. MAPKs modulate the levels and function of many proteins, including proinflammatory factors and factors in the p21/p53 and p16/RB pathways, the main senescence-regulatory axes. Through these actions, MAPKs implement key traits of senescence-growth arrest, cell survival, and the senescence-associated secretory phenotype (SASP). In this review, we summarize and discuss our current knowledge of the impact of MAPKs in senescence. In addition, given that eliminating or suppressing senescent cells can improve health span, we discuss the function and possible exploitation of MAPKs in the elimination (senolysis) or suppression (senostasis) of senescent cells.
Collapse
Affiliation(s)
- Carlos Anerillas
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, 21224, USA
| | - Kotb Abdelmohsen
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, 21224, USA
| | - Myriam Gorospe
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, 251 Bayview Blvd., Baltimore, MD, 21224, USA.
| |
Collapse
|
10
|
Yin H, Jiang Z, Wang S, Zhang P. Actinomycin D-Activated RNase L Promotes H2A.X/H2B-Mediated DNA Damage and Apoptosis in Lung Cancer Cells. Front Oncol 2019; 9:1086. [PMID: 31750234 PMCID: PMC6842983 DOI: 10.3389/fonc.2019.01086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 10/02/2019] [Indexed: 01/24/2023] Open
Abstract
Background: Chemotherapy is an essential component for comprehensive cancer treatment, while drug resistance usually fails therapy. DNA repair mechanism of cancer cells restrains the efficacy of therapeutics targeting DNA damage. Investigating target-inducing irreversible cell death of cancer cells may be promising. Methods: The present study used lung cancer cell lines, transplanted tumor model of lung cancers derived from patients with lung adenocarcinoma, and molecular experiments to investigate the effects and mechanism of Actinomycin D (Act D)-activated RNase L in lung canceers. Results: We report that RNase L, when activated by Act D, induces Caspase-3/PARP activation. The latter further enables ROCK-1 to initiate subsequent membrane blebbing and, meanwhile, result in DNA cleavage and cell cycle arrest mediated by H2A.X/H2B-p21 axis, leading to irreversible DNA damage, and apoptosis of lung cancer cells. The present study highlighted the crucial role of RNase L in triggering apoptosis mechanism through the Caspase-3/ROCK-1/PARP/H2A.X+H2B/p21 axis during Act D treatment. Moreover, activation of RNase L suppressed the tumor formation and the induction of lung cancer stem cells. Conclusion: This study unveiled the regulatory function and related mechanism of RNase L and implied the promising application of therapeutics targeting RNase L in lung cancer.
Collapse
Affiliation(s)
- Huijing Yin
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical School, Fudan University, Shanghai, China.,Department of Immunology, Tongji University School of Medicine, Shanghai, China
| | - Zhengyu Jiang
- Faculty of Anesthesiology, Changhai Hospital, Second Military Medical University, Shanghai, China
| | - Shuoer Wang
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai, China.,Central Laboratory, The Fifth People's Hospital of Shanghai, Fudan University, Shanghai, China
| | - Ping Zhang
- Cancer Institute, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical School, Fudan University, Shanghai, China
| |
Collapse
|
11
|
Deng X, Luo Q, Dong F, Xu L, Tang X. [Tristetraprolin inhibits autophagy in cultured lung cancer cells via the nuclear factor-κB pathway]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2019; 39:313-319. [PMID: 31068309 DOI: 10.12122/j.issn.1673-4254.2019.03.09] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
OBJECTIVE To explore the expression of the RNA-binding protein tristetraprolin in lung adenocarcinoma cells and its molecular mechanism for inhibiting autophagy. METHODS Quantitative real-time PCR and Western blotting were performed to detect the expression of autophagy-related genes (including Beclin1, LC3-Ⅱ/LC3-Ⅰ and SQSTM1/p62) in cultured lung adenocarcinoma cells at 24, 48 and 72 h after transient transfection with a tristetraprolin-overexpressing plasmid and the empty plasmid. The effects of transfection with the tristetraprolin-overexpressing plasmid and empty plasmids in the presence or absence of tumor necrosis factor-α (TNF-α) on the expressions of nuclear factor-κB (NF-κB) p65, c-rel, and p50 were examined in lung adenocarcinoma cells using immunofluorescence assay and Western blotting. The cells were also transfected with the IκBα-mut plasmid and the tristetraprolin-overexpressing plasmid, either alone or in combination, and the changes in the expressions of tristetraprolin and autophagy-related genes were detected using RT-qPCR and Western blotting. RESULTS The expressions of tristetraprolin were significantly reduced at both the mRNA and protein levels in lung adenocarcinoma cells (P < 0.001). Overexpression of tristetraprolin in the cells significantly lowered the expressions of autophagy-related genes Beclin1 and the ratio of LC3-Ⅱ/LC3-Ⅰ at the mRNA and protein levels (P < 0.001), obviously lowered the expressions of NF-κB p65 and c-rel, and almost totally blocked the nuclear translocation of NF-κB p65 and c-rel (P < 0.05); the expression of p50, however, did not undergo significant changes in response to tristetraprolin overexpression (P > 0.05). The inhibitory effect of tristetraprolin overexpression on autophagy was abrogated by transfection of the cells with IκBα-mut plasmid, which blocked the NF-κB signaling pathway. Co-transfection of the cells with IκBα-mut also attenuated the inhibitory effect of tristetraprolin overexpression on Beclin1 and the LC3-Ⅱ/LC3-Ⅰ ratio at both the mRNA and protein levels (P < 0.05). CONCLUSIONS The expression of tristetraprolin is low in lung adenocarcinoma cells. Tristetraprolin overexpression causes inhibition of autophagy in lung adenocarcinoma cells possibly by blocking NF-κB p65 and c-rel nuclear translocation.
Collapse
Affiliation(s)
- Xiaoya Deng
- Department of Respiratory and Critical Care Medicine, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Qinli Luo
- Department of Respiratory and Critical Care Medicine, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Fei Dong
- Department of Respiratory and Critical Care Medicine, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Li Xu
- Department of Respiratory and Critical Care Medicine, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Xiaokui Tang
- Department of Respiratory and Critical Care Medicine, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| |
Collapse
|
12
|
Relevance of Non-Targeted Effects for Radiotherapy and Diagnostic Radiology; A Historical and Conceptual Analysis of Key Players. Cancers (Basel) 2019; 11:cancers11091236. [PMID: 31450803 PMCID: PMC6770832 DOI: 10.3390/cancers11091236] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 08/16/2019] [Accepted: 08/18/2019] [Indexed: 11/17/2022] Open
Abstract
Non-targeted effects (NTE) such as bystander effects or genomic instability have been known for many years but their significance for radiotherapy or medical diagnostic radiology are far from clear. Central to the issue are reported differences in the response of normal and tumour tissues to signals from directly irradiated cells. This review will discuss possible mechanisms and implications of these different responses and will then discuss possible new therapeutic avenues suggested by the analysis. Finally, the importance of NTE for diagnostic radiology and nuclear medicine which stems from the dominance of NTE in the low-dose region of the dose–response curve will be presented. Areas such as second cancer induction and microenvironment plasticity will be discussed.
Collapse
|
13
|
Al-Khalaf HH, Aboussekhra A. AUF1 positively controls angiogenesis through mRNA stabilization-dependent up-regulation of HIF-1α and VEGF-A in human osteosarcoma. Oncotarget 2019; 10:4868-4879. [PMID: 31448053 PMCID: PMC6690669 DOI: 10.18632/oncotarget.27115] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 06/29/2019] [Indexed: 12/19/2022] Open
Abstract
Osteosarcoma is the most common malignant bone tumor in children, adolescents, and young adults. This pleiomorphic tumor depends on new blood vessel development, also known as angiogenesis, for tumor growth and metastasis. Therefore, it’s of utmost importance to identify the key genes and pathways that regulate this pro-metastatic process in order to develop more efficient therapies. Here, we have shown that the RNA-binding protein AUF1 positively regulates the expression of the pro-angiogenic factor VEGF-A and its positive regulator HIF-1alpha through direct binding and stabilization of their mRNAs. This effect is mediated through the seeding sequence of the AUF1 protein in the VEGF-A and HIF-1alpha 3’UTR sequences. As a consequence, the expression of the 3 genes was highly correlative in various osteosarcoma cell lines, and AUF1 enhanced the pro-angiogenic capabilities of osteosarcoma cells both in vitro and in vivo. Indeed, while inhibition of AUF1 using specific siRNA suppressed the pro-angiogenic effects of osteosarcoma cells, ectopic expression of AUF1 enhanced the pro-angiogenic effect in a VEGF-A-dependent manner. Therefore, in the era of targeted therapy, anti-angiogenic therapies targeting AUF1 could provide effective methods for treating osteosarcoma.
Collapse
Affiliation(s)
- Huda H Al-Khalaf
- Department of Molecular Oncology, King Faisal Specialist Hospital and Research Center, Riyadh 11211, KSA.,The National Center for Stem Cell Technology, King Abdulaziz City for Science and Technology, Riyadh 11211, KSA
| | - Abdelilah Aboussekhra
- Department of Molecular Oncology, King Faisal Specialist Hospital and Research Center, Riyadh 11211, KSA
| |
Collapse
|
14
|
Roles of Tristetraprolin in Tumorigenesis. Int J Mol Sci 2018; 19:ijms19113384. [PMID: 30380668 PMCID: PMC6274954 DOI: 10.3390/ijms19113384] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 10/25/2018] [Accepted: 10/26/2018] [Indexed: 12/13/2022] Open
Abstract
Genetic loss or mutations in tumor suppressor genes promote tumorigenesis. The prospective tumor suppressor tristetraprolin (TTP) has been shown to negatively regulate tumorigenesis through destabilizing the messenger RNAs of critical genes implicated in both tumor onset and tumor progression. Regulation of TTP has therefore emerged as an important issue in tumorigenesis. Similar to other tumor suppressors, TTP expression is frequently downregualted in various human cancers, and its low expression is correlated with poor prognosis. Additionally, disruption in the regulation of TTP by various mechanisms results in the inactivation of TTP protein or altered TTP expression. A recent study showing alleviation of Myc-driven lymphomagenesis by the forced expression of TTP has shed light on new therapeutic avenues for cancer prevention and treatment through the restoration of TTP expression. In this review, we summarize key oncogenes subjected to the TTP-mediated mRNA degradation, and discuss how dysregulation of TTP can contribute to tumorigenesis. In addition, the control mechanism underlying TTP expression at the posttranscriptional and posttranslational levels will be discussed.
Collapse
|
15
|
Dong F, Li C, Wang P, Deng X, Luo Q, Tang X, Xu L. The RNA binding protein tristetraprolin down-regulates autophagy in lung adenocarcinoma cells. Exp Cell Res 2018; 367:89-96. [PMID: 29577897 DOI: 10.1016/j.yexcr.2018.03.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/15/2018] [Accepted: 03/21/2018] [Indexed: 02/08/2023]
Abstract
Tristetraprolin (TTP) is the most well-known member of RNA-binding zinc-finger protein that play a significant role in accelerating mRNA decay. Increasingly studies have reported that TTP was functioned as a tumor suppressor gene in several types of carcinomas, while its underlying mechanism is not clear yet. In the current study, we found that TTP overexpression decreased cell proliferation and increased cell death in lung adenocarcinoma cells, with the cell cycle arrest at the S phase. Remarkably, instead of inducing cell apoptosis directly, TTP overexpression alters cell autophagy. Our studies demonstrate that TTP overexpression has no effect on apoptosis related genes, but decreases the expression of autophagy-related genes, including Beclin 1 and LC3II. The level of autophagy flux assessed by infection with the mGFP-RFP-LC3 adenovirus construction has been blocked by TTP overexpression. Moreover, the autophagic vacuoles number detected by transmission electron microscopy decreased with TTP expression up-regulation. Our results indicate, for the first time, that TTP suppresses cell proliferation and increases cell death through cell autophagy pathway in lung cancer cells. Our study provides a new angle of view for TTP function as a tumor suppressor which could be targeted in tumor treatment.
Collapse
Affiliation(s)
- Fei Dong
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Cen Li
- Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Pu Wang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xiaoya Deng
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qinli Luo
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Xiaokui Tang
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
| | - Li Xu
- Department of Respiratory and Critical Care Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
| |
Collapse
|
16
|
Zhang Y, Jiang F, He H, Ye J, Mao X, Guo Q, Wu SL, Zhong W, Wu CL, Lin N. Identification of a novel microRNA-mRNA regulatory biomodule in human prostate cancer. Cell Death Dis 2018; 9:301. [PMID: 29467540 PMCID: PMC5833360 DOI: 10.1038/s41419-018-0293-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 12/06/2017] [Accepted: 01/04/2018] [Indexed: 12/29/2022]
Abstract
Our recent study identified a list of differentially expressed microRNAs (miRNAs) in human prostate cancer (PCa) tissues compared to adjacent benign prostate tissues. In the current study, to identify the crucial miRNA-mRNA regulatory biomodule involved into prostate carcinogenesis based on the previous miRNA expression profile in PCa, we proposed an integrated systematic approach which combined miRNA-mediated gene expression regulatory network analysis, experimental validations in vitro and in vivo, as well as clinical significance evaluation. As a result, the CCND1-RNASEL-CDKN1A-TP73-MDM2-UBE2I axis was identified as a bottleneck in the miRNA-mediated gene expression regulatory network of PCa according to network topological analysis. The direct binding relationship between TP73 and PCa downregulated miR-193a-5p, and the direct binding relationship between UBE2I and PCa upregulated miR-188-5p were both experimentally validated. In addition, miR-193a-5p had a more significant regulatory effect on the tumor promoter isoform of TP73-deltaNp73 than on the tumor suppressive isoform of TP73-TAp73. Importantly, the deregulation of either the miR-193a-5p-TP73 or miR-188-5p-UBE2I axes was significantly associated with aggressive progression and poor prognosis in PCa patients. Gain- and loss-of-function experiments showed that miR-193a-5p efficiently inhibited in vitro PCa cell proliferation, migration, and invasion, and in vivo tumor growth, and markedly induced PCa cell apoptosis via regulating TP73 with a corresponding suppression of the CCND1-RNASEL-CDKN1A-MDM2 axis. In contrast, miR-188-5p exerted its tumor promoter roles through targeting UBE2I with a subsequent activation of the CCND1-RNASEL-CDKN1A-MDM2 axis. Taken together, this integrated analysis revealed the potential roles of the miR-193a-5p/TP73 and miR-188-5p/UBE2i negative regulation pairs in PCa. In addition to the significant clinical relevance, miR-193a-5p- and miR-188-5p-regulated CCND1-RNASEL-CDKN1A-TP73-MDM2-UBE2I signaling may be a novel regulatory biomodule in prostate carcinogenesis.
Collapse
Affiliation(s)
- Yanqiong Zhang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.,Department of Urology & Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
| | - Funeng Jiang
- Department of Urology, Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, 510180, China
| | - Huichan He
- Urology Key Laboratory of Guangdong Province, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, 510230, China
| | - Jianheng Ye
- Department of Urology & Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.,Department of Urology, Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, 510180, China
| | - Xia Mao
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qiuyan Guo
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Shu-Lin Wu
- Department of Urology & Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
| | - Weide Zhong
- Department of Urology, Guangdong Key Laboratory of Clinical Molecular Medicine and Diagnostics, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, 510180, China. .,Urology Key Laboratory of Guangdong Province, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, 510230, China.
| | - Chin-Lee Wu
- Department of Urology & Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA.
| | - Na Lin
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
| |
Collapse
|
17
|
Al-Haj L, Khabar KSA. The intracellular pyrimidine 5'-nucleotidase NT5C3A is a negative epigenetic factor in interferon and cytokine signaling. Sci Signal 2018; 11:11/518/eaal2434. [PMID: 29463777 DOI: 10.1126/scisignal.aal2434] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The enzyme pyrimidine 5'-nucleotidase (NT5C3A), which mediates nucleotide catabolism, was previously thought to be restricted to blood cells. We showed that expression of the gene encoding NT5C3A was induced by type I interferons (IFNs) in multiple cell types and that NT5C3A suppressed cytokine production through inhibition of the nuclear factor κB (NF-κB) pathway. NT5C3A expression required both an intronic IFN-stimulated response element and the IFN-stimulated transcription factor IRF1. Overexpression of NT5C3A, but not of its catalytic mutants, suppressed IL-8 production by HEK293 cells. Whereas knockdown of NT5C3A enhanced tumor necrosis factor (TNF)-stimulated IL-8 production, it reduced the IFN-mediated suppression of Il8 expression. Overexpression of NT5C3A increased the abundance of NAD+ and the activation of the sirtuins SIRT1 and SIRT6, which are NAD+-dependent deacetylases. NT5C3A-stimulated sirtuin activity resulted in deacetylation of histone H3 and the NF-κB subunit RelA (also known as p65), both of which were associated with the proximal region of the Il8 promoter, thus repressing the transcription of Il8 Together, these data identify an anti-inflammatory pathway that depends on the catalytic activity of NT5C3A and functions as a negative feedback regulator of inflammatory cytokine signaling.
Collapse
Affiliation(s)
- Latifa Al-Haj
- King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia
| | - Khalid S A Khabar
- King Faisal Specialist Hospital and Research Centre, Riyadh 11211, Saudi Arabia.
| |
Collapse
|
18
|
ZFP36L1 and ZFP36L2 inhibit cell proliferation in a cyclin D-dependent and p53-independent manner. Sci Rep 2018; 8:2742. [PMID: 29426877 PMCID: PMC5807420 DOI: 10.1038/s41598-018-21160-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 01/29/2018] [Indexed: 12/28/2022] Open
Abstract
ZFP36 family members include ZFP36, ZFP36L1, and ZFP36L2, which belong to CCCH-type zinc finger proteins with two tandem zinc finger (TZF) regions. Whether ZFP36L1 and ZFP36L2 have antiproliferative activities similar to that of ZFP36 is unclear. In this study, when ZFP36L1 or ZFP36L2 was overexpressed in T-REx-293 cells, cell proliferation was dramatically inhibited and the cell cycle was arrested at the G1 phase. The levels of cell-cycle-related proteins, including cyclin B, cyclin D, cyclin A, and p21, decreased; however, p53 increased in ZFP36L1-or ZFP36L2-overexpressing T-REx-293 cells. Forced expression of ZFP36L1 or ZFP36L2 also inhibited cell proliferation and cyclin D gene expression in three human colorectal cancer cell lines: HCT116 p53+/+, HCT116 p53−/−, and SW620 (mutated p53) cells. However, it increased p53 and p21 expression only in HCT116 p53+/+ cells. Knockdown of ZFP36L1 or ZFP36L2 increased cell proliferation and cyclin D expression; furthermore, the mutation of the TZF of ZFP36L1 or ZFP36L2 caused them to lose their antiproliferative ability, to the extent that they could not inhibit cyclin D expression in these three cell lines. The results indicated that ZFP36L1 and ZFP36L2 play a negative role in cell proliferation; the underlying mechanisms might be mediated through a cyclin D-dependent and p53-independent pathway.
Collapse
|
19
|
Rusin A, Seymour C, Mothersill C. Chronic fatigue and immune deficiency syndrome (CFIDS), cellular metabolism, and ionizing radiation: a review of contemporary scientific literature and suggested directions for future research. Int J Radiat Biol 2018; 94:212-228. [DOI: 10.1080/09553002.2018.1422871] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Andrej Rusin
- Department of Biology, McMaster University, Hamilton, Canada
| | - Colin Seymour
- Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Canada
| | | |
Collapse
|
20
|
The Fragment HMGA2-sh-3p20 from HMGA2 mRNA 3'UTR Promotes the Growth of Hepatoma Cells by Upregulating HMGA2. Sci Rep 2017; 7:2070. [PMID: 28522832 PMCID: PMC5437003 DOI: 10.1038/s41598-017-02311-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 04/10/2017] [Indexed: 01/12/2023] Open
Abstract
High mobility group A2 (HMGA2) plays a crucial role in the development of cancer. However, the mechanism by which HMGA2 promotes the growth of hepatocellular carcinoma (HCC) remains unclear. Here, we explore the hypothesis that HMGA2 may enhance the growth of hepatoma cells through a fragment based on the secondary structure of HMGA2 mRNA 3′-untranslated region (3′UTR). Bioinformatics analysis showed that HMGA2 mRNA displayed a hairpin structure within its 3′UTR, termed HMGA2-sh. Mechanistically, RNA immunoprecipitation assays showed that the microprocessor Drosha or DGCR8 interacted with HMGA2 mRNA in hepatoma cells. Then, Dicer contributes to the generation of the fragment HMGA2-sh-3p20 from the HMGA2-sh. HMGA2-sh-3p20 was screened by PCR analysis. Interestingly, HMGA2-sh-3p20 increased the expression of HMGA2 through antagonizing the tristetraprolin (TTP)-mediated degradation of HMGA2. HMGA2-sh-3p20 inhibited the expression of PTEN by targeting the 3′UTR of PTEN mRNA. In addition, the overexpression of PTEN could downregulate HMGA2 expression. Significantly, we documented the ability of HMGA2-sh-3p20 to promote the growth of hepatoma cells in vitro and in vivo. Thus, we conclude that the fragment HMGA2-sh-3p20 from HMGA2 mRNA 3′UTR promotes the growth of hepatoma cells by upregulating HMGA2. Our finding provides new insights into the mechanism by which HMGA2 enhances hepatocarcinogenesis.
Collapse
|
21
|
Wang YT, Tseng PH, Chen CL, Han DS, Chi YC, Tseng FY, Yang WS. Human serum RNase-L level is inversely associated with metabolic syndrome and age. Cardiovasc Diabetol 2017; 16:46. [PMID: 28399925 PMCID: PMC5387300 DOI: 10.1186/s12933-017-0522-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Accepted: 03/17/2017] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Ribonuclease-L (RNase-L) was known to be a ubiquitous enzyme involved in several cellular functions, especially innate immunity. It was recently shown to participate in adipogenesis in rodents. Here, we developed a method to measure serum levels of RNase-L and analyzed the relationship between RNase-L and metabolic syndrome (MetS). METHODS A total of 396 subjects were recruited from a health check-up program. An in-house RNase-L immunoassay was developed. The serum RNase-L levels of these subjects were measured, and the association of MetS-related factors with RNase-L levels was assessed. RESULTS The mean serum level of RNase-L of the subjects with MetS were lower than those without (16.5 ± 6.4 vs. 18.4 ± 8.0 μg/ml, P = 0.018). The subjects with central obesity, elevated blood pressure, or impaired fasting glucose also had lower serum RNase-L levels in comparison to those without. In multivariate linear regression analysis, diastolic blood pressure (β = -0.129, P = 0.024) and high-density lipoprotein cholesterol (HDL-C) (β = 0.127, P = 0.036) were related to serum RNase-L. For every 5 μg/ml increase in serum RNase-L levels, it is associated with a reduced risk of MetS (OR 0.83, 95% CI 0.71-0.98, P = 0.028), central obesity (OR 0.82, 95% CI 0.71-0.94, P = 0.005), or low HDL-C (OR 0.86, 95% CI 0.74-1.00, P = 0.042). Moreover, age is inversely related to serum RNase-L levels in various analyses. CONCLUSIONS The serum RNase-L levels were inversely associated with MetS, unfavorable metabolic profiles, and age.
Collapse
Affiliation(s)
- Yi-Ting Wang
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, No. 7, Chung-San South Road, Taipei, 10002, Taiwan
| | - Ping-Huei Tseng
- Division of Gastroenterology, Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-San South Road, Taipei, 10002, Taiwan
| | - Chi-Ling Chen
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, No. 7, Chung-San South Road, Taipei, 10002, Taiwan.,Graduate Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, No. 17, Xu-Zhou Road, Taipei, 10055, Taiwan
| | - Der-Sheng Han
- Department of Physical Medicine and Rehabilitation, National Taiwan University Hospital Beihu Branch, No.87, Neijiang St., Taipei, 10800, Taiwan.,Community and Geriatric Medicine Research Center, National Taiwan University Hospital Beihu Branch, No.87, Neijiang St., Taipei, 10800, Taiwan
| | - Yu-Chiao Chi
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, No. 7, Chung-San South Road, Taipei, 10002, Taiwan.,Division of Endocrinology & Metabolism, Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-San South Road, Taipei, 10002, Taiwan
| | - Fen-Yu Tseng
- Division of Endocrinology & Metabolism, Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-San South Road, Taipei, 10002, Taiwan
| | - Wei-Shiung Yang
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, No. 7, Chung-San South Road, Taipei, 10002, Taiwan. .,Division of Endocrinology & Metabolism, Department of Internal Medicine, National Taiwan University Hospital, No. 7, Chung-San South Road, Taipei, 10002, Taiwan. .,Center for Obesity, Lifestyle and Metabolic Surgery, National Taiwan University Hospital, No. 7, Chung-San South Road, Taipei, 10002, Taiwan. .,Graduate Institute of Medical Genomics & Proteomics, College of Medicine, National Taiwan University, No.1, Sec. 1, Jen-Ai Road, Taipei, 10051, Taiwan. .,, No. 1, Chang-Teh St., Taipei, 10048, Taiwan.
| |
Collapse
|
22
|
Galloway A, Turner M. Cell cycle RNA regulons coordinating early lymphocyte development. WILEY INTERDISCIPLINARY REVIEWS-RNA 2017; 8. [PMID: 28231639 PMCID: PMC5574005 DOI: 10.1002/wrna.1419] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 01/20/2017] [Accepted: 01/23/2017] [Indexed: 01/19/2023]
Abstract
Lymphocytes undergo dynamic changes in gene expression as they develop from progenitor cells lacking antigen receptors, to mature cells that are prepared to mount immune responses. While transcription factors have established roles in lymphocyte development, they act in concert with post-transcriptional and post-translational regulators to determine the proteome. Furthermore, the post-transcriptional regulation of RNA regulons consisting of mRNAs whose protein products act cooperatively allows RNA binding proteins to exert their effects at multiple points in a pathway. Here, we review recent evidence demonstrating the importance of RNA binding proteins that control the cell cycle in lymphocyte development and discuss the implications for tumorigenesis. WIREs RNA 2017, 8:e1419. doi: 10.1002/wrna.1419 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Alison Galloway
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, UK
| | - Martin Turner
- Laboratory of Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, UK
| |
Collapse
|
23
|
Vlasova-St Louis I, Bohjanen PR. Post-transcriptional regulation of cytokine and growth factor signaling in cancer. Cytokine Growth Factor Rev 2016; 33:83-93. [PMID: 27956133 DOI: 10.1016/j.cytogfr.2016.11.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022]
Abstract
Cytokines and growth factors regulate cell proliferation, differentiation, migration and apoptosis, and play important roles in coordinating growth signal responses during development. The expression of cytokine genes and the signals transmitted through cytokine receptors are tightly regulated at several levels, including transcriptional and post-transcriptional levels. A majority of cytokine mRNAs, including growth factor transcripts, contain AU-rich elements (AREs) in their 3' untranslated regions that control gene expression by regulating mRNA degradation and changing translational rates. In addition, numerous proteins involved in transmitting signals downstream of cytokine receptors are regulated at the level of mRNA degradation by GU-rich elements (GREs) found in their 3' untranslated regions. Abnormal stabilization and overexpression of ARE or GRE-containing transcripts had been observed in many malignancies, which is a consequence of the malfunction of RNA-binding proteins. In this review, we briefly summarize the role of AREs and GREs in regulating mRNA turnover to coordinate cytokine and growth factor expression, and we describe how dysregulation of mRNA degradation mechanisms contributes to the development and progression of cancer.
Collapse
Affiliation(s)
| | - Paul R Bohjanen
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
24
|
A link between adipogenesis and innate immunity: RNase-L promotes 3T3-L1 adipogenesis by destabilizing Pref-1 mRNA. Cell Death Dis 2016; 7:e2458. [PMID: 27831565 PMCID: PMC5260905 DOI: 10.1038/cddis.2016.323] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 12/20/2022]
Abstract
Ribonuclease L (RNase-L) is an endoribonuclease well known for its roles in innate immunity. Recently it has been shown to regulate several cellular functions by modulating the levels of specific mRNAs. In this study, we investigated whether RNase-L may regulate adipocyte functions. We showed that knockdown of RNase-L reduced 3T3-L1 adipocyte differentiation and lipid accumulation. After mRNA profiling, we found that upregulation of Pref-1 mRNA, an inhibitory regulator of adipogenesis, could explain the reduced adipocyte differentiation with RNase-L downregulation. The signaling molecules downstream to Pref-1, including focal adhesion kinase, extracellular signal-regulated kinases and SRY-box 9, were activated by RNase-L suppression. The presence of Pref-1 mRNA was detected in the mRNP complexes precipitated by anti-RNase-L antibody. Moreover, the Pref-1 mRNA decay rate was raised by elevated RNase-L ribonuclease activity. Finally, in stable cell clones with RNase-L silencing, suppression of Pref-1 mRNA by specific siRNA partially recovered the adipocyte differentiation phenotype. Consistent with our findings, meta-analysis of 45 public array datasets from seven independent studies showed a significant negative relationship between RNase-L and Pref-1 mRNA levels in mouse adipose tissues. Higher RNase-L and lower Pref-1 mRNAs were found in the adipose tissues of high-fat diet mice compared to those of ND mice. In line with this, our animal data also showed that the adipose tissues of obese rats contained higher RNase-L and lower Pref-1 expression in comparison to that of lean rats. This study demonstrated that Pref-1 mRNA is a novel substrate of RNase-L. RNase-L is involved in adipocyte differentiation through destabilizing Pref-1 mRNA, thus offering a new link among RNA metabolism, innate immunity and adipogenesis in obesity progression.
Collapse
|
25
|
Xu L, Ning H, Gu L, Wang Q, Lu W, Peng H, Cui W, Ying B, Ross CR, Wilson GM, Wei L, Wold WSM, Liu J. Tristetraprolin induces cell cycle arrest in breast tumor cells through targeting AP-1/c-Jun and NF-κB pathway. Oncotarget 2016; 6:41679-91. [PMID: 26497679 PMCID: PMC4747181 DOI: 10.18632/oncotarget.6149] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 09/30/2015] [Indexed: 12/12/2022] Open
Abstract
The main characteristic of cancers, including breast cancer, is the ability of cancer cells to proliferate uncontrollably. However, the underlying mechanisms of cancer cell proliferation, especially those regulated by the RNA binding protein tristetraprolin (TTP), are not completely understood. In this study, we found that TTP inhibits cell proliferation in vitro and suppresses tumor growth in vivo through inducing cell cycle arrest at the S phase. Our studies demonstrate that TTP inhibits c-Jun expression through the C-terminal Zn finger and therefore increases Wee1 expression, a regulatory molecule which controls cell cycle transition from the S to the G2 phase. In contrast to the well-known function of TTP in regulating mRNA stability, TTP inhibits c-Jun expression at the level of transcription by selectively blocking NF-κB p65 nuclear translocation. Reconstitution of NF-κB p65 completely abolishes the inhibition of c-Jun transcription by TTP. Moreover, reconstitution of c-Jun in TTP-expressing breast tumor cells diminishes Wee1 overexpression and promotes cell proliferation. Our results indicate that TTP suppresses c-Jun expression that results in Wee1 induction which causes cell cycle arrest at the S phase and inhibition of cell proliferation. Our study provides a new pathway for TTP function as a tumor suppressor which could be targeted in tumor treatment.
Collapse
Affiliation(s)
- Li Xu
- Department of Respiratory Medicine, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.,Division of Infectious Diseases, Allergy and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Huan Ning
- Division of Infectious Diseases, Allergy and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Ling Gu
- Division of Infectious Diseases, Allergy and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Qinghong Wang
- Division of Infectious Diseases, Allergy and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Wenbao Lu
- Division of Infectious Diseases, Allergy and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Hui Peng
- Division of Infectious Diseases, Allergy and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Weiguang Cui
- Division of Infectious Diseases, Allergy and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Baoling Ying
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Christina R Ross
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Gerald M Wilson
- Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Lin Wei
- Department of Immunology, School of Basic Medicine, Hebei Medical University, Shijiazhuang, Hebei, China
| | - William S M Wold
- Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, St. Louis, MO, USA
| | - Jianguo Liu
- Division of Infectious Diseases, Allergy and Immunology, Department of Internal Medicine, Saint Louis University School of Medicine, St. Louis, MO, USA
| |
Collapse
|
26
|
Khabar KSA. Hallmarks of cancer and AU-rich elements. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27251431 PMCID: PMC5215528 DOI: 10.1002/wrna.1368] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/05/2016] [Accepted: 05/09/2016] [Indexed: 12/14/2022]
Abstract
Post‐transcriptional control of gene expression is aberrant in cancer cells. Sustained stabilization and enhanced translation of specific mRNAs are features of tumor cells. AU‐rich elements (AREs), cis‐acting mRNA decay determinants, play a major role in the posttranscriptional regulation of many genes involved in cancer processes. This review discusses the role of aberrant ARE‐mediated posttranscriptional processes in each of the hallmarks of cancer, including sustained cellular growth, resistance to apoptosis, angiogenesis, invasion, and metastasis. WIREs RNA 2017, 8:e1368. doi: 10.1002/wrna.1368 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Khalid S A Khabar
- King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| |
Collapse
|
27
|
Toompuu M, Kärblane K, Pata P, Truve E, Sarmiento C. ABCE1 is essential for S phase progression in human cells. Cell Cycle 2016; 15:1234-47. [PMID: 26985706 DOI: 10.1080/15384101.2016.1160972] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
ABCE1 is a highly conserved protein universally present in eukaryotes and archaea, which is crucial for the viability of different organisms. First identified as RNase L inhibitor, ABCE1 is currently recognized as an essential translation factor involved in several stages of eukaryotic translation and ribosome biogenesis. The nature of vital functions of ABCE1, however, remains unexplained. Here, we study the role of ABCE1 in human cell proliferation and its possible connection to translation. We show that ABCE1 depletion by siRNA results in a decreased rate of cell growth due to accumulation of cells in S phase, which is accompanied by inefficient DNA synthesis and reduced histone mRNA and protein levels. We infer that in addition to the role in general translation, ABCE1 is involved in histone biosynthesis and DNA replication and therefore is essential for normal S phase progression. In addition, we analyze whether ABCE1 is implicated in transcript-specific translation via its association with the eIF3 complex subunits known to control the synthesis of cell proliferation-related proteins. The expression levels of a few such targets regulated by eIF3A, however, were not consistently affected by ABCE1 depletion.
Collapse
Affiliation(s)
- Marina Toompuu
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| | - Kairi Kärblane
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| | - Pille Pata
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| | - Erkki Truve
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| | - Cecilia Sarmiento
- a Department of Gene Technology , Tallinn University of Technology , Tallinn , Estonia
| |
Collapse
|
28
|
Human RNase L tunes gene expression by selectively destabilizing the microRNA-regulated transcriptome. Proc Natl Acad Sci U S A 2015; 112:15916-21. [PMID: 26668391 DOI: 10.1073/pnas.1513034112] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Double-stranded RNA (dsRNA) activates the innate immune system of mammalian cells and triggers intracellular RNA decay by the pseudokinase and endoribonuclease RNase L. RNase L protects from pathogens and regulates cell growth and differentiation by destabilizing largely unknown mammalian RNA targets. We developed an approach for transcriptome-wide profiling of RNase L activity in human cells and identified hundreds of direct RNA targets and nontargets. We show that this RNase L-dependent decay selectively affects transcripts regulated by microRNA (miR)-17/miR-29/miR-200 and other miRs that function as suppressors of mammalian cell adhesion and proliferation. RNase L mimics the effects of these miRs and acts as a suppressor of proliferation and adhesion in mammalian cells. Our data suggest that RNase L-dependent decay serves to establish an antiproliferative state via destabilization of the miR-regulated transcriptome.
Collapse
|
29
|
Ryu J, Yoon NA, Seong H, Jeong JY, Kang S, Park N, Choi J, Lee DH, Roh GS, Kim HJ, Cho GJ, Choi WS, Park JY, Park JW, Kang SS. Resveratrol Induces Glioma Cell Apoptosis through Activation of Tristetraprolin. Mol Cells 2015; 38:991-7. [PMID: 26537190 PMCID: PMC4673414 DOI: 10.14348/molcells.2015.0197] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 09/03/2015] [Accepted: 09/07/2015] [Indexed: 12/30/2022] Open
Abstract
Tristetraprolin (TTP) is an AU-rich elements (AREs)-binding protein, which regulates the decay of AREs-containing mRNAs such as proto-oncogenes, anti-apoptotic genes and immune regulatory genes. Despite the low expression of TTP in various human cancers, the mechanism involving suppressed expression of TTP is not fully understood. Here, we demonstrate that Resveratrol (3,5,4'-trihydroxystilbene, Res), a naturally occurring compound, induces glioma cell apoptosis through activation of tristetraprolin (TTP). Res increased TTP expression in U87MG human glioma cells. Res-induced TTP destabilized the urokinase plasminogen activator and urokinase plasminogen activator receptor mRNAs by binding to the ARE regions containing the 3' untranslated regions of their mRNAs. Furthermore, TTP induced by Res suppressed cell growth and induced apoptosis in the human glioma cells. Because of its regulation of TTP expression, these findings suggest that the bioactive dietary compound Res can be used as a novel anti-cancer agent for the treatment of human malignant gliomas.
Collapse
Affiliation(s)
- Jinhyun Ryu
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Nal Ae Yoon
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Hyemin Seong
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Joo Yeon Jeong
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Seokmin Kang
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Nammi Park
- Department of Physiology, Institute of Health Sciences, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Jungil Choi
- Gyeongnam Department of Environmental Toxicology and Chemistry, Korea Institute of Toxicology (KIT), Jinju 660-844,
Korea
| | - Dong Hoon Lee
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Gu Seob Roh
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Hyun Joon Kim
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Gyeong Jae Cho
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Wan Sung Choi
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| | - Jae-Yong Park
- School of Biosystem and Biomedical Science, College of Health Science, Korea University, Seoul 02841,
Korea
| | - Jeong Woo Park
- Department of Biological Sciences, University of Ulsan, Ulsan 680-749,
Korea
| | - Sang Soo Kang
- Department of Anatomy and Convergence Medical Science, Institute of Health Science, School of Medicine, Gyeongsang National University, Jinju 52727,
Korea
| |
Collapse
|
30
|
Brennan-Laun SE, Ezelle HJ, Li XL, Hassel BA. RNase-L control of cellular mRNAs: roles in biologic functions and mechanisms of substrate targeting. J Interferon Cytokine Res 2015; 34:275-88. [PMID: 24697205 DOI: 10.1089/jir.2013.0147] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
RNase-L is a mediator of type 1 interferon-induced antiviral activity that has diverse and critical cellular roles, including the regulation of cell proliferation, differentiation, senescence and apoptosis, tumorigenesis, and the control of the innate immune response. Although RNase-L was originally shown to mediate the endonucleolytic cleavage of both viral and ribosomal RNAs in response to infection, more recent evidence indicates that RNase-L also functions in the regulation of cellular mRNAs as an important mechanism by which it exerts its diverse biological functions. Despite this growing body of work, many questions remain regarding the roles of mRNAs as RNase-L substrates. This review will survey known and putative mRNA substrates of RNase-L, propose mechanisms by which it may selectively cleave these transcripts, and postulate future clinical applications.
Collapse
Affiliation(s)
- Sarah E Brennan-Laun
- 1 Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine , Baltimore, Maryland
| | | | | | | |
Collapse
|
31
|
Brennan-Laun SE, Li XL, Ezelle HJ, Venkataraman T, Blackshear PJ, Wilson GM, Hassel BA. RNase L attenuates mitogen-stimulated gene expression via transcriptional and post-transcriptional mechanisms to limit the proliferative response. J Biol Chem 2014; 289:33629-43. [PMID: 25301952 DOI: 10.1074/jbc.m114.589556] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cellular response to mitogens is tightly regulated via transcriptional and post-transcriptional mechanisms to rapidly induce genes that promote proliferation and efficiently attenuate their expression to prevent malignant growth. RNase L is an endoribonuclease that mediates diverse antiproliferative activities, and tristetraprolin (TTP) is a mitogen-induced RNA-binding protein that directs the decay of proliferation-stimulatory mRNAs. In light of their roles as endogenous proliferative constraints, we examined the mechanisms and functional interactions of RNase L and TTP to attenuate a mitogenic response. Mitogen stimulation of RNase L-deficient cells significantly increased TTP transcription and the induction of other mitogen-induced mRNAs. This regulation corresponded with elevated expression of serum-response factor (SRF), a master regulator of mitogen-induced transcription. RNase L destabilized the SRF transcript and formed a complex with SRF mRNA in cells providing a mechanism by which RNase L down-regulates SRF-induced genes. TTP and RNase L proteins interacted in cells suggesting that RNase L is directed to cleave TTP-bound RNAs as a mechanism of substrate specificity. Consistent with their concerted function in RNA turnover, the absence of either RNase L or TTP stabilized SRF mRNA, and a subset of established TTP targets was also regulated by RNase L. RNase L deficiency enhanced mitogen-induced proliferation demonstrating its functional role in limiting the mitogenic response. Our findings support a model of feedback regulation in which RNase L and TTP target SRF mRNA and SRF-induced transcripts. Accordingly, meta-analysis revealed an enrichment of RNase L and TTP targets among SRF-regulated genes suggesting that the RNase L/TTP axis represents a viable target to inhibit SRF-driven proliferation in neoplastic diseases.
Collapse
Affiliation(s)
- Sarah E Brennan-Laun
- From the Marlene and Stewart Greenebaum Cancer Center, Departments of Microbiology and Immunology and
| | - Xiao-Ling Li
- the Genetics Branch, NCI, National Institutes of Health, Bethesda, Maryland 20892
| | - Heather J Ezelle
- From the Marlene and Stewart Greenebaum Cancer Center, Departments of Microbiology and Immunology and the Research Services, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201, and
| | | | - Perry J Blackshear
- the Laboratory of Signal Transduction, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709
| | - Gerald M Wilson
- From the Marlene and Stewart Greenebaum Cancer Center, Biochemistry and Molecular Biology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Bret A Hassel
- From the Marlene and Stewart Greenebaum Cancer Center, Departments of Microbiology and Immunology and the Research Services, Baltimore Veterans Affairs Medical Center, Baltimore, Maryland 21201, and
| |
Collapse
|
32
|
Al-Khalaf HH, Aboussekhra A. MicroRNA-141 and microRNA-146b-5p inhibit the prometastatic mesenchymal characteristics through the RNA-binding protein AUF1 targeting the transcription factor ZEB1 and the protein kinase AKT. J Biol Chem 2014; 289:31433-47. [PMID: 25261470 DOI: 10.1074/jbc.m114.593004] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
miR-141 and miR-146b-5p are two important tumor suppressor microRNAs, which control several cancer-related genes and processes. In the present report, we have shown that these microRNAs bind specific sites at the 3'-untranslated region (UTR) of the mRNA-binding protein AUF1, leading to its down-regulation. This inverse correlation between the levels of these microRNAs and AUF1 has been identified in various osteosarcoma cell lines. Additionally, we present clear evidence that AUF1 promotes mesenchymal features in osteosarcoma cells and that miR-141 and miR-146b-5p suppress this prometastatic process through AUF1 repression. Indeed, both microRNAs suppressed the invasion/migration and proliferation abilities of osteosarcoma cells through inhibiting the AKT protein kinase in an AUF1-dependent manner. We have also shown that AUF1 binds to and stabilizes the mRNA of the AKT activator phosphoinositide-dependent kinase-1 (PDK1). Furthermore, miR-141 and miR-146b-5p positively regulate the epithelial markers (E-cadherin and Epcam) and repress the mesenchymal markers (N-cadherin, Vimentin, Twist2, and ZEB1). These effects were mediated via the repression of the epithelial-to-mesenchymal inducer ZEB1 through targeting AUF1, which binds the 3'-UTR of the ZEB1 mRNA and reduces its turnover. These results indicate that at least some tumor suppressor functions of miR-141 and miR-146b-5p are mediated through the repression of the oncogenic potentials of AUF1. Therefore, these 3'-UTR-directed post-transcriptional gene expression regulators constitute promising new targets for diagnostic and/or therapeutic interventions.
Collapse
Affiliation(s)
- Huda H Al-Khalaf
- From the Department of Molecular Oncology, King Faisal Specialist Hospital and Research Centre, MBC 03, P.O. Box 3354, Riyadh 11211, Saudi Arabia and the Joint Center for Genomics Research, King Abdulaziz City for Science and Technology, Riyadh 11211, Saudi Arabia
| | - Abdelilah Aboussekhra
- From the Department of Molecular Oncology, King Faisal Specialist Hospital and Research Centre, MBC 03, P.O. Box 3354, Riyadh 11211, Saudi Arabia and
| |
Collapse
|
33
|
Wig-1 regulates cell cycle arrest and cell death through the p53 targets FAS and 14-3-3σ. Oncogene 2014; 33:4407-17. [PMID: 24469038 PMCID: PMC4150987 DOI: 10.1038/onc.2013.594] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 10/31/2013] [Accepted: 12/16/2013] [Indexed: 01/29/2023]
Abstract
Wig-1, also known as ZMAT3, is a p53 target gene that encodes an RNA-binding zinc-finger protein involved in the regulation of mRNA stability through binding to AU-rich elements (AREs). We have used microarray analysis to identify novel Wig-1 target mRNAs. We identified 2447 transcripts with >fourfold differential expression between Wig-1 and control small interfering (si)RNA-treated HCT116 cells. Several p53 target genes were among the deregulated transcripts. We found that Wig-1 regulates FAS and 14-3-3σ mRNA independently of p53. We show that Wig-1 binds to FAS mRNA 3'-UTR and decreases its stability through an ARE in the 3'-UTR. Depletion of Wig-1 was associated with increased cell death and reduced cell cycle arrest upon DNA damage. Our results suggest a role of Wig-1 as a survival factor that directs the p53 stress response toward cell cycle arrest rather than apoptosis through the regulation of FAS and 14-3-3σ mRNA levels.
Collapse
|
34
|
Gupta A, Rath PC. Expression of mRNA and protein-protein interaction of the antiviral endoribonuclease RNase L in mouse spleen. Int J Biol Macromol 2014; 69:307-18. [PMID: 24780566 DOI: 10.1016/j.ijbiomac.2014.04.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 04/18/2014] [Accepted: 04/21/2014] [Indexed: 10/25/2022]
Abstract
The interferon-inducible, 2',5'-oligoadenylate (2-5A)-dependent endoribonuclease, RNase L is a unique antiviral RNA-degrading enzyme involved in RNA-metabolism, translational regulation, stress-response besides its anticancer/tumor-suppressor and antibacterial functions. RNase L represents complex cellular RNA-regulations in mammalian cells but diverse functions of RNase L are not completely explained by its 2-5A-regulated endoribonuclease activity. We hypothesized that RNase L has housekeeping function(s) through interaction with cellular proteins. We investigated RNase L mRNA expression in mouse tissues by RT-PCR and its protein-protein interaction in spleen by GST-pulldown and immunoprecipitation assays followed by proteomic analysis. RNase L mRNA is constitutively and differentially expressed in nine different mouse tissues, its level is maximum in immunological tissues (spleen, thymus and lungs), moderate in reproductive tissues (testis and prostate) and low in metabolic tissues (kidney, brain, liver and heart). Cellular proteins from mouse spleen [fibronectin precursor, β-actin, troponin I, myosin heavy chain 9 (non-muscle), growth-arrest specific protein 11, clathrin light chain B, a putative uncharacterized protein (Ricken cDNA 8030451F13) isoform (CRA_d) and alanyl tRNA synthetase] were identified as cellular RNase L-interacting proteins. Thus our results suggest for more general cellular functions of RNase L through protein-protein interactions in the spleen for immune response in mammals.
Collapse
Affiliation(s)
- Ankush Gupta
- Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Pramod C Rath
- Molecular Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067, India.
| |
Collapse
|
35
|
Enteropathogenic Escherichia coli inhibits type I interferon- and RNase L-mediated host defense to disrupt intestinal epithelial cell barrier function. Infect Immun 2014; 82:2802-14. [PMID: 24733098 DOI: 10.1128/iai.00105-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) primarily infects children in developing countries and causes diarrhea that can be deadly. EPEC pathogenesis occurs through type III secretion system (T3SS)-mediated injection of effectors into intestinal epithelial cells (IECs); these effectors alter actin dynamics, modulate the immune response, and disrupt tight junction (TJ) integrity. The resulting compromised barrier function and increased gastrointestinal (GI) permeability may be responsible for the clinical symptoms of infection. Type I interferon (IFN) mediates anti-inflammatory activities and serves essential functions in intestinal immunity and homeostasis; however, its role in the immune response to enteric pathogens, such as EPEC, and its impact on IEC barrier function have not been examined. Here, we report that IFN-β is induced following EPEC infection and regulates IEC TJ proteins to maintain barrier function. The EPEC T3SS effector NleD counteracts this protective activity by inhibiting IFN-β induction and enhancing tumor necrosis factor alpha to promote barrier disruption. The endoribonuclease RNase L is a key mediator of IFN induction and action that promotes TJ protein expression and IEC barrier integrity. EPEC infection inhibits RNase L in a T3SS-dependent manner, providing a mechanism by which EPEC evades IFN-induced antibacterial activities. This work identifies novel roles for IFN-β and RNase L in IEC barrier functions that are targeted by EPEC effectors to escape host defense mechanisms and promote virulence. The IFN-RNase L axis thus represents a potential therapeutic target for enteric infections and GI diseases involving compromised barrier function.
Collapse
|
36
|
Chafin CB, Regna NL, Dai R, Caudell DL, Reilly CM. MicroRNA-let-7a expression is increased in the mesangial cells of NZB/W mice and increases IL-6 production in vitro. Autoimmunity 2014; 46:351-62. [PMID: 24001203 DOI: 10.3109/08916934.2013.773976] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Recent evidence supports a role for epigenetic alterations in the pathogenesis of systemic lupus erythematosus (SLE). MicroRNAs (miRNAs or miRs) are endogenous epigenetic regulators whose expression is altered in many diseases, including SLE. IL-6 is an inflammatory cytokine produced by mesangial cells during lupus nephritis (LN). IL-6 contains a potential binding site for miRNA-let-7a (let-7a) in its 3' untranslated region (UTR). We found let-7a expression was significantly increased in the mesangial cells of pre-diseased and actively diseased New Zealand Black/White (NZB/W) mice compared to age-matched New Zealand White (NZW) mice. Overexpression of let-7a in vitro increased IL-6 production in stimulated mesangial cells compared to non-transfected controls. Inhibition of let-7a did not significantly affect immune-stimulated IL-6 production. When stimulated mesangial cells overexpressing let-7a were treated with the transcription inhibitor Actinomycin D (ActD), IL-6 was degraded faster, consistent with the direct targeting of the 3' UTR of IL-6 by let-7a. Overexpression of let-7a increased the expression of tristetraprolin (TTP), an RNA-binding protein (RBP) that has 5 potential binding regions in the 3' UTR of IL-6. ActD inhibited the transcription of proteins including TTP that may contribute to the let-7a-mediated increase in immune-stimulated IL-6 production. These data show that NZB/W mice have higher let-7a expression than NZW mice and that increased let-7a expression in vitro increases IL-6 production in stimulated mesangial cells. Further studies examining the role of let-7a expression in inflammation are warranted.
Collapse
Affiliation(s)
- Cristen B Chafin
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.
| | | | | | | | | |
Collapse
|
37
|
MacNeil AJ, Jiao SC, McEachern LA, Yang YJ, Dennis A, Yu H, Xu Z, Marshall JS, Lin TJ. MAPK kinase 3 is a tumor suppressor with reduced copy number in breast cancer. Cancer Res 2013; 74:162-72. [PMID: 24233520 DOI: 10.1158/0008-5472.can-13-1310] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cancers are initiated as a result of changes that occur in the genome. Identification of gains and losses in the structure and expression of tumor-suppressor genes and oncogenes lies at the root of the understanding of cancer cell biology. Here, we show that the mitogen-activated protein kinase (MAPK) MKK3 suppresses the growth of breast cancer, in which it varies in copy number. A pervasive loss of MKK3 gene copy number in patients with breast cancer is associated with an impairment of MKK3 expression and protein level in malignant tissues. To assess the functional role of MKK3 in breast cancer, we showed in an animal model that MKK3 activity is required for suppression of tumor growth. Active MKK3 enhanced expression of the cyclin-dependent kinase inhibitors p21(Cip1/Waf1) and p27(Kip1), leading to increased cell-cycle arrest in G1 phase of the cell cycle. Our results reveal the functional significance of MKK3 as a tumor suppressor and improve understanding of the dynamic role of the MAPK pathway in tumor progression.
Collapse
Affiliation(s)
- Adam J MacNeil
- Authors' Affiliations: Departments of Microbiology and Immunology, Pediatrics, Physiology and Biophysics, and Pathology, Dalhousie University; Beatrice Hunter Cancer Research Institute, Halifax, Nova Scotia, Canada; Department of Medical Oncology, General Hospital of the People's Liberation Army, Beijing; and Institute of Zoonosis, College of Animal Sciences and Veterinary Medicine, Jilin University, Changchun, Jilin, China
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Al-Khalaf HH, Aboussekhra A. p16(INK4A) positively regulates p21(WAF1) expression by suppressing AUF1-dependent mRNA decay. PLoS One 2013; 8:e70133. [PMID: 23894605 PMCID: PMC3720951 DOI: 10.1371/journal.pone.0070133] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Accepted: 06/17/2013] [Indexed: 01/01/2023] Open
Abstract
Background p16INK4a and p21WAF1 are two independent cyclin-dependent kinase inhibitors encoded by the CDKN2A and CDKN1A genes, respectively. p16INK4a and p21WAF1 are similarly involved in various anti-cancer processes, including the regulation of the critical G1 to S phase transition of the cell cycle, senescence and apoptosis. Therefore, we sought to elucidate the molecular mechanisms underlying the link between these two important tumor suppressor proteins. Methodology/Principal Findings We have shown here that the p16INK4a protein positively controls the expression of p21WAF1 in both human and mouse cells. p16INK4a stabilizes the CDKN1A mRNA through negative regulation of the mRNA decay-promoting AUF1 protein. Immunoprecipitation of AUF1-associated RNAs followed by quantitative RT-PCR indicated that endogenous AUF1 binds to the CDKN1A mRNA in a p16INK4A-dependent manner. Furthermore, while AUF1 down-regulation increased the expression level of the CDKN1A mRNA, the concurrent knockdown of AUF1 and CDKN2A, using specific silencing RNAs, restored the normal expression of the gene. Moreover, we used EGFP reporter fused to the CDKN2A AU-rich element (ARE) to demonstrate that p16INK4A regulation of the CDKN1A mRNA is AUF1- and ARE-dependent. Furthermore, ectopic expression of p16INK4A in p16INK4A-deficient breast epithelial MCF-10A cells significantly increased the level of p21WAF1, with no effect on cell proliferation. In addition, we have shown direct correlation between p16INK4a and p21WAF1 levels in various cancer cell lines. Conclusion/Significance These findings show that p16INK4a stabilizes the CDKN1A mRNA in an AUF1-dependent manner, and further confirm the presence of a direct link between the 2 important cancer-related pathways, pRB/p16INK4A and p14ARF/p53/p21WAF1.
Collapse
Affiliation(s)
- Huda H. Al-Khalaf
- Department of Molecular Oncology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- The Joint Center for Genomics Research, King Abdulaziz City for Science and Technology, Riyadh, KSA
| | - Abdelilah Aboussekhra
- Department of Molecular Oncology, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
- * E-mail:
| |
Collapse
|
39
|
Brooks SA, Blackshear PJ. Tristetraprolin (TTP): interactions with mRNA and proteins, and current thoughts on mechanisms of action. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1829:666-79. [PMID: 23428348 PMCID: PMC3752887 DOI: 10.1016/j.bbagrm.2013.02.003] [Citation(s) in RCA: 296] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 01/25/2013] [Accepted: 02/04/2013] [Indexed: 12/14/2022]
Abstract
Changes in mRNA stability and translation are critical control points in the regulation of gene expression, particularly genes encoding growth factors, inflammatory mediators, and proto-oncogenes. Adenosine and uridine (AU)-rich elements (ARE), often located in the 3' untranslated regions (3'UTR) of mRNAs, are known to target transcripts for rapid decay. They are also involved in the regulation of mRNA stability and translation in response to extracellular cues. This review focuses on one of the best characterized ARE binding proteins, tristetraprolin (TTP), the founding member of a small family of CCCH tandem zinc finger proteins. In this survey, we have reviewed the current status of TTP interactions with mRNA and proteins, and discussed current thinking about TTP's mechanism of action to promote mRNA decay. We also review the proposed regulation of TTP's functions by phosphorylation. Finally, we have discussed emerging evidence for TTP operating as a translational regulator. This article is part of a Special Issue entitled: RNA Decay mechanisms.
Collapse
Affiliation(s)
- Seth A. Brooks
- Veterans Affairs Medical Center, White River Junction, Vermont, USA
- Department of Medicine, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, USA
| | - Perry J. Blackshear
- The Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina, USA
- Departments of Medicine and Biochemistry, Duke University Medical Center, Durham, North Carolina USA
| |
Collapse
|
40
|
Lee JY, Kim HJ, Yoon NA, Lee WH, Min YJ, Ko BK, Lee BJ, Lee A, Cha HJ, Cho WJ, Park JW. Tumor suppressor p53 plays a key role in induction of both tristetraprolin and let-7 in human cancer cells. Nucleic Acids Res 2013; 41:5614-25. [PMID: 23595149 PMCID: PMC3675463 DOI: 10.1093/nar/gkt222] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Tristetraprolin (TTP) and let-7 microRNA exhibit suppressive effects on cell growth through down-regulation of oncogenes. Both TTP and let-7 are often repressed in human cancers, thereby promoting oncogenesis by derepressing their target genes. However, the precise mechanism of this repression is unknown. We here demonstrate that p53 stimulated by the DNA-damaging agent doxorubicin (DOX) induced the expression of TTP in cancer cells. TTP in turn increased let-7 levels through down-regulation of Lin28a. Correspondingly, cancer cells with mutations or inhibition of p53 failed to induce the expression of both TTP and let-7 on treatment with DOX. Down-regulation of TTP by small interfering RNAs attenuated the inhibitory effect of DOX on let-7 expression and cell growth. Therefore, TTP provides an important link between p53 activation induced by DNA damage and let-7 biogenesis. These novel findings provide a mechanism for the widespread decrease in TTP and let-7 and chemoresistance observed in human cancers.
Collapse
Affiliation(s)
- Ji Young Lee
- Department of Biological Sciences, University of Ulsan, Ulsan 680-749, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Al-Ahmadi W, Al-Ghamdi M, Al-Souhibani N, Khabar KSA. miR-29a inhibition normalizes HuR over-expression and aberrant AU-rich mRNA stability in invasive cancer. J Pathol 2013; 230:28-38. [PMID: 23401122 PMCID: PMC3732382 DOI: 10.1002/path.4178] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 01/02/2013] [Accepted: 02/04/2013] [Indexed: 12/23/2022]
Abstract
The activities of RNA-binding proteins are perturbed in several pathological conditions, including cancer. These proteins include tristetraprolin (TTP, ZFP36) and HuR (ELAVL1), which respectively promote the decay or stability of adenylate-uridylate-rich (AU-rich) mRNAs. Here, we demonstrated that increased stabilization and subsequent over-expression of HuR mRNA were coupled to TTP deficiency. These findings were observed in breast cancer cell lines with an invasive phenotype and were further confirmed in ZFP36-knockout mouse fibroblasts. We show that TTP–HuR imbalance correlated with increased expression of AU-rich element (ARE) mRNAs that code for cancer invasion genes. The microRNA miR-29a was abundant in invasive breast cancer cells when compared to non-tumourigenic cell types. When normal breast cells were treated with miR-29a, HuR mRNA and protein expression were up-regulated. MiR-29a recognized a seed target in the TTP 3′ UTR and a cell-permeable miR-29a inhibitor increased TTP activity towards HuR 3′ UTR. This led to HuR mRNA destabilization and restoration of the aberrant TTP–HuR axis. Subsequently, the cancer invasion factors uPA, MMP-1 and MMP-13, and cell invasiveness, were decreased. The TTP:HuR mRNA ratios were also perturbed in samples from invasive breast cancer patients when compared with normal tissues, and were associated with invasion gene expression. This study demonstrates that an aberrant ARE-mediated pathway in invasive cancer can be normalized by targeting the aberrant and functionally coupled TTP–HuR axis, indicating a potential therapeutic approach. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Collapse
Affiliation(s)
- Wijdan Al-Ahmadi
- Molecular Biomedicine Programme, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | | | | | | |
Collapse
|
42
|
Structural basis for cytosolic double-stranded RNA surveillance by human oligoadenylate synthetase 1. Proc Natl Acad Sci U S A 2013; 110:1652-7. [PMID: 23319625 DOI: 10.1073/pnas.1218528110] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The human sensor of double-stranded RNA (dsRNA) oligoadenylate synthetase 1 (hOAS1) polymerizes ATP into 2',5'-linked iso-RNA (2-5A) involved in innate immunity, cell cycle, and differentiation. We report the crystal structure of hOAS1 in complex with dsRNA and 2'-deoxy ATP at 2.7 Å resolution, which reveals the mechanism of cytoplasmic dsRNA recognition and activation of oligoadenylate synthetases. Human OAS1 recognizes dsRNA using a previously uncharacterized protein/RNA interface that forms via a conformational change induced by binding of dsRNA. The protein/RNA interface involves two minor grooves and has no sequence-specific contacts, with the exception of a single hydrogen bond between the -NH(2) group of nucleobase G17 and the carbonyl oxygen of serine 56. Using a biochemical readout, we show that hOAS1 undergoes more than 20,000-fold activation upon dsRNA binding and that canonical or GU-wobble substitutions produce dsRNA mutants that retain either full or partial activity, in agreement with the crystal structure. Ultimately, the binding of dsRNA promotes an elaborate conformational rearrangement in the N-terminal lobe of hOAS1, which brings residues D75, D77, and D148 into proximity and creates coordination geometry for binding of two catalytic Mg(2+) ions and ATP. The assembly of this critical active-site structure provides the gate that couples binding of dsRNA to the production and downstream functions of 2-5A.
Collapse
|