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Vijayakumar A, Majumder M, Yin S, Brobbey C, Karam J, Howley B, Howe P, Berto S, Madan L, Gan W, Palanisamy V. PRMT5-mediated arginine methylation of FXR1 is essential for RNA binding in cancer cells. Nucleic Acids Res 2024; 52:7225-7244. [PMID: 38709899 PMCID: PMC11229354 DOI: 10.1093/nar/gkae319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 02/29/2024] [Accepted: 04/11/2024] [Indexed: 05/08/2024] Open
Abstract
Emerging evidence indicates that arginine methylation promotes the stability of arginine-glycine-rich (RGG) motif-containing RNA-binding proteins (RBPs) and regulates gene expression. Here, we report that post-translational modification of FXR1 enhances the binding with mRNAs and is involved in cancer cell growth and proliferation. Independent point mutations in arginine residues of FXR1's nuclear export signal (R386 and R388) and RGG (R453, R455 and R459) domains prevent it from binding to RNAs that form G-quadruplex (G4) RNA structures. Disruption of G4-RNA structures by lithium chloride failed to bind with FXR1, indicating its preference for G4-RNA structure containing mRNAs. Furthermore, loss-of-function of PRMT5 inhibited FXR1 methylation both in vivo and in vitro, affecting FXR1 protein stability, inhibiting RNA-binding activity and cancer cell growth and proliferation. Finally, the enhanced crosslinking and immunoprecipitation (eCLIP) analyses reveal that FXR1 binds with the G4-enriched mRNA targets such as AHNAK, MAP1B, AHNAK2, HUWE1, DYNC1H1 and UBR4 and controls its mRNA expression in cancer cells. Our findings suggest that PRMT5-mediated FXR1 methylation is required for RNA/G4-RNA binding, which promotes gene expression in cancer cells. Thus, FXR1's structural characteristics and affinity for RNAs preferentially G4 regions provide new insights into the molecular mechanism of FXR1 in oral cancer cells.
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Affiliation(s)
- Anitha Vijayakumar
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
- Division of Molecular Medicine, Department of Internal Medicine, University of New Mexico, Albuquerque, NM 87131, USA
| | - Mrinmoyee Majumder
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Shasha Yin
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Charles Brobbey
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Joseph Karam
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Breege Howley
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Philip H Howe
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Stefano Berto
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Lalima K Madan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Wenjian Gan
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Viswanathan Palanisamy
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
- Division of Molecular Medicine, Department of Internal Medicine, University of New Mexico, Albuquerque, NM 87131, USA
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2
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Majumder M, Janakiraman H, Chakraborty P, Vijayakumar A, Mayhue S, Yu H, Dincman T, Martin R, O’Quinn E, Mehrotra S, Palanisamy V. RNA-binding protein HuR reprograms immune T cells and promotes oral squamous cell carcinoma. ORAL ONCOLOGY REPORTS 2024; 10:100296. [PMID: 38681116 PMCID: PMC11044901 DOI: 10.1016/j.oor.2024.100296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2024]
Abstract
Hu Antigen R, also known as ELAVL1 (HuR), is a key posttranscriptional regulator in eukaryotic cells. HuR overexpression promotes several malignancies, including head and neck squamous cell carcinoma (HNSCC). However, its immune dysfunction-associated tumorigenesis pathways remain unknown. We examined HuR's effects on oral malignancies and immune cell function in vitro and in vivo using oral carcinoma cells and transgenic HuR knockout (KO) mice. CRISPR/Cas9-mediated HuR deletion in mice syngeneic oral cancer cells eliminated colony formation and tumor development. HuR-KO tumors had a lower tumor volume, fewer CD4+CD25+FoxP3+ regulatory T cells, and more CD8+ T cells, suggesting that HuR may suppress the immune response during oral cancer progression. In contrast, HuR KO oral epithelial tissues are resistant to 4NQO-induced oral malignancies compared to control tumor-bearing mice. HuR KO mice showed fewer Tregs and greater IFN levels than WT tumor-bearing mice, suggesting anticancer activity. Finally, the HuR inhibitor pyrvinium pamoate lowers tumor burden by enhancing CD8+ infiltration at the expense of CD4+, suggesting anticancer benefits. Thus, HuR-dependent oral neoplasia relies on immunological dysfunction, suggesting that decreasing HuR may boost antitumor potential and offer a novel HNSCC therapy.
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Affiliation(s)
| | | | | | | | - Sari Mayhue
- Department of Biochemistry and Molecular Biology, USA
| | - Hong Yu
- Oral Health Sciences, College of Dental Medicine, USA
| | - Toros Dincman
- Department of Haematology and Oncology, College of Medicine, USA
| | - Romeo Martin
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Elizabeth O’Quinn
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| | | | - Viswanathan Palanisamy
- Department of Biochemistry and Molecular Biology, USA
- Division of Molecular Medicine, Department of Internal Medicine, UNM Comprehensive Cancer Center, University of New Mexico, Albuquerque, NM, 87131, USA
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Schroeder HT, De Lemos Muller CH, Heck TG, Krause M, Homem de Bittencourt PI. Heat shock response during the resolution of inflammation and its progressive suppression in chronic-degenerative inflammatory diseases. Cell Stress Chaperones 2024; 29:116-142. [PMID: 38244765 PMCID: PMC10939074 DOI: 10.1016/j.cstres.2024.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/22/2024] Open
Abstract
The heat shock response (HSR) is a crucial biochemical pathway that orchestrates the resolution of inflammation, primarily under proteotoxic stress conditions. This process hinges on the upregulation of heat shock proteins (HSPs) and other chaperones, notably the 70 kDa family of heat shock proteins, under the command of the heat shock transcription factor-1. However, in the context of chronic degenerative disorders characterized by persistent low-grade inflammation (such as insulin resistance, obesity, type 2 diabetes, nonalcoholic fatty liver disease, and cardiovascular diseases) a gradual suppression of the HSR does occur. This work delves into the mechanisms behind this phenomenon. It explores how the Western diet and sedentary lifestyle, culminating in the endoplasmic reticulum stress within adipose tissue cells, trigger a cascade of events. This cascade includes the unfolded protein response and activation of the NOD-like receptor pyrin domain-containing protein-3 inflammasome, leading to the emergence of the senescence-associated secretory phenotype and the propagation of inflammation throughout the body. Notably, the activation of the NOD-like receptor pyrin domain-containing protein-3 inflammasome not only fuels inflammation but also sabotages the HSR by degrading human antigen R, a crucial mRNA-binding protein responsible for maintaining heat shock transcription factor-1 mRNA expression and stability on heat shock gene promoters. This paper underscores the imperative need to comprehend how chronic inflammation stifles the HSR and the clinical significance of evaluating the HSR using cost-effective and accessible tools. Such understanding is pivotal in the development of innovative strategies aimed at the prevention and treatment of these chronic inflammatory ailments, which continue to take a heavy toll on global health and well-being.
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Affiliation(s)
- Helena Trevisan Schroeder
- Laboratory of Cellular Physiology (FisCel), Department of Physiology, Institute of Basic Health Sciences (ICBS), Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil
| | - Carlos Henrique De Lemos Muller
- Laboratory of Inflammation, Metabolism and Exercise Research (LAPIMEX), Department of Physiology, ICBS, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
| | - Thiago Gomes Heck
- Post Graduate Program in Integral Health Care (PPGAIS-UNIJUÍ/UNICRUZ/URI), Regional University of Northwestern Rio Grande Do Sul State (UNIJUI) and Post Graduate Program in Mathematical and Computational Modeling (PPGMMC), UNIJUI, Ijuí, Rio Grande do Sul, Brazil
| | - Mauricio Krause
- Laboratory of Inflammation, Metabolism and Exercise Research (LAPIMEX), Department of Physiology, ICBS, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil
| | - Paulo Ivo Homem de Bittencourt
- Laboratory of Cellular Physiology (FisCel), Department of Physiology, Institute of Basic Health Sciences (ICBS), Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil.
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Goswami B, Nag S, Ray PS. Fates and functions of RNA-binding proteins under stress. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023:e1825. [PMID: 38014833 DOI: 10.1002/wrna.1825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 10/03/2023] [Accepted: 10/30/2023] [Indexed: 11/29/2023]
Abstract
Exposure to stress activates a well-orchestrated set of changes in gene expression programs that allow the cell to cope with and adapt to the stress, or undergo programmed cell death. RNA-protein interactions, mediating all aspects of post-transcriptional regulation of gene expression, play crucial roles in cellular stress responses. RNA-binding proteins (RBPs), which interact with sequence/structural elements in RNAs to control the steps of RNA metabolism, have therefore emerged as central regulators of post-transcriptional responses to stress. Following exposure to a variety of stresses, the dynamic alterations in the RNA-protein interactome enable cells to respond to intracellular or extracellular perturbations by causing changes in mRNA splicing, polyadenylation, stability, translation, and localization. As RBPs play a central role in determining the cellular proteome both qualitatively and quantitatively, it has become increasingly evident that their abundance, availability, and functions are also highly regulated in response to stress. Exposure to stress initiates a series of signaling cascades that converge on post-translational modifications (PTMs) of RBPs, resulting in changes in their subcellular localization, association with stress granules, extracellular export, proteasomal degradation, and RNA-binding activities. These alterations in the fate and function of RBPs directly impact their post-transcriptional regulatory roles in cells under stress. Adopting the ubiquitous RBP HuR as a prototype, three scenarios illustrating the changes in nuclear-cytoplasmic localization, RNA-binding activity, export and degradation of HuR in response to inflammation, genotoxic stress, and heat shock depict the complex and interlinked regulatory mechanisms that control the fate and functions of RBPs under stress. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Binita Goswami
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohanpur, West Bengal, India
| | - Sharanya Nag
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohanpur, West Bengal, India
| | - Partho Sarothi Ray
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohanpur, West Bengal, India
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5
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Xiao H, Ye X, Vishwakarma V, Preet R, Dixon DA. CRC-derived exosomes containing the RNA binding protein HuR promote lung cell proliferation by stabilizing c-Myc mRNA. Cancer Biol Ther 2022; 23:139-149. [PMID: 35130122 PMCID: PMC8824215 DOI: 10.1080/15384047.2022.2034455] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
HuR overexpression is related to poor survival in patients with colon cancer. HuR overexpression leads to stabilization of tumor-promoting mRNAs by binding to 3′UTR-resident AREs. Exosomes, nanosized lipid bilayer vesicles, mediate many steps in cancer progression. The potential role of exosomal HuR in colon cancer lung metastasis is unclear. HuR expression was assessed immunohistochemically in tumor tissue samples from 20 patients with metastatic or nonmetastatic colon cancer and colon cancer lung metastasis and benign lung disease samples from ten patients. Exosomes were isolated from HCT116 WT and HuR KO colon cancer cells, and uptake of PKH67- and PKH26-labeled exosomes by BEAS-2B cells was evaluated using fluorescence and confocal microscopy. C-Myc and p21protein and mRNA levels were measured by western blotting and RT-qPCR, respectively. In clinical patients, HuR overexpression was significantly enhanced in colon tissues of patients with lung metastasis. HuR expression was higher in lung tissue with metastasis of colonic origin than with benign lung disease. The effect of HuR-containing CRC exosomes compared to HuR-deficient exosomes on wound closure was observed as enhanced proliferation. BEAS-2B cell migration and invasion were enhanced after HuR-containing exosomes treatment. BEAS-2B cells showed similar uptake of PKH67 (HCT116 WT)- and PKH26 (HCT116 HuR KO)-labeled exosomes. Exosomal HuR stabilized c-Myc mRNA and downregulated p21 expression, leading to G1/S transition, in human bronchial epithelial cells. HuR overexpression is associated with lung metastasis in colon cancer patients. Exosomal HuR derived from colon cancer cells alter the biological effect on normal lung epithelial cells.
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Affiliation(s)
- Hui Xiao
- Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai, China.,Department of Molecular Biosciences, University of Kansas Cancer Center, University of Kansas, Lawrence, Kansas, USA
| | - Xiong Ye
- College of Clinical Medicine, Shanghai University of Medicine & Health Science, Shanghai, China
| | - Vikalp Vishwakarma
- Department of Molecular Biosciences, University of Kansas Cancer Center, University of Kansas, Lawrence, Kansas, USA
| | - Ranjan Preet
- Department of Molecular Biosciences, University of Kansas Cancer Center, University of Kansas, Lawrence, Kansas, USA
| | - Dan A Dixon
- Department of Molecular Biosciences, University of Kansas Cancer Center, University of Kansas, Lawrence, Kansas, USA
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6
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Majumder M, Chakraborty P, Mohan S, Mehrotra S, Palanisamy V. HuR as a molecular target for cancer therapeutics and immune-related disorders. Adv Drug Deliv Rev 2022; 188:114442. [PMID: 35817212 DOI: 10.1016/j.addr.2022.114442] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/12/2022] [Accepted: 07/05/2022] [Indexed: 11/19/2022]
Abstract
The control of eukaryotic gene expression occurs at multiple levels, from transcription to messenger RNA processing, transport, localization, turnover, and translation. RNA-binding proteins control gene expression and are involved in different stages of mRNA processing, including splicing, maturation, turnover, and translation. A ubiquitously expressed RBP Human antigen R is engaged in the RNA processes mentioned above but, most importantly, controls mRNA stability and turnover. Dysregulation of HuR is linked to many diseases, including cancer and other immune-related disorders. HuR targets mRNAs containing AU-rich elements at their 3'untranslated region, which encodes proteins involved in cell growth, proliferation, tumor formation, angiogenesis, immune evasion, inflammation, invasion, and metastasis. HuR overexpression has been reported in many tumor types, which led to a poor prognosis for patients. Hence, HuR is considered an appealing drug target for cancer treatment. Therefore, multiple attempts have been made to identify small molecule inhibitors for blocking HuR functions. This article reviews the current prospects of drugs that target HuR in numerous cancer types, their mode of action, and off-target effects. Furthermore, we will summarize drugs that interfered with HuR-RNA interactions and established themselves as novel therapeutics. We will also highlight the significance of HuR overexpression in multiple cancers and discuss its role in immune functions. This review provides evidence of a new era of HuR-targeted small molecules that can be used for cancer therapeutics either as a monotherapy or in combination with other cancer treatment modalities.
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Affiliation(s)
- Mrinmoyee Majumder
- Department of Biochemistry and Molecular Biology, Charleston, SC 29425, USA
| | - Paramita Chakraborty
- Department of Surgery, College of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
| | - Sarumathi Mohan
- Department of Biochemistry and Molecular Biology, Charleston, SC 29425, USA
| | - Shikhar Mehrotra
- Department of Surgery, College of Medicine, Medical University of South Carolina, Charleston, SC 29425, USA
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7
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Guha A, Waris S, Nabors LB, Filippova N, Gorospe M, Kwan T, King PH. The versatile role of HuR in Glioblastoma and its potential as a therapeutic target for a multi-pronged attack. Adv Drug Deliv Rev 2022; 181:114082. [PMID: 34923029 PMCID: PMC8916685 DOI: 10.1016/j.addr.2021.114082] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/15/2021] [Accepted: 12/12/2021] [Indexed: 02/03/2023]
Abstract
Glioblastoma (GBM) is a malignant and aggressive brain tumor with a median survival of ∼15 months. Resistance to treatment arises from the extensive cellular and molecular heterogeneity in the three major components: glioma tumor cells, glioma stem cells, and tumor-associated microglia and macrophages. Within this triad, there is a complex network of intrinsic and secreted factors that promote classic hallmarks of cancer, including angiogenesis, resistance to cell death, proliferation, and immune evasion. A regulatory node connecting these diverse pathways is at the posttranscriptional level as mRNAs encoding many of the key drivers contain adenine- and uridine rich elements (ARE) in the 3' untranslated region. Human antigen R (HuR) binds to ARE-bearing mRNAs and is a major positive regulator at this level. This review focuses on basic concepts of ARE-mediated RNA regulation and how targeting HuR with small molecule inhibitors represents a plausible strategy for a multi-pronged therapeutic attack on GBM.
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Affiliation(s)
- Abhishek Guha
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Saboora Waris
- Shaheed Zulfiqar Ali Bhutto Medical University, PIMS, G-8, Islamabad, Pakistan
| | - Louis B Nabors
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Natalia Filippova
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Myriam Gorospe
- Laboratory of Genetics and Genomics, National Institute on Aging Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, United States
| | - Thaddaeus Kwan
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Peter H King
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Birmingham Veterans Affairs Medical Center, Birmingham, AL 35294, United States.
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8
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Osma-Garcia IC, Capitan-Sobrino D, Mouysset M, Bell SE, Lebeurrier M, Turner M, Diaz-Muñoz MD. The RNA-binding protein HuR is required for maintenance of the germinal centre response. Nat Commun 2021; 12:6556. [PMID: 34772950 PMCID: PMC8590059 DOI: 10.1038/s41467-021-26908-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 10/22/2021] [Indexed: 11/09/2022] Open
Abstract
The germinal centre (GC) is required for the generation of high affinity antibodies and immunological memory. Here we show that the RNA binding protein HuR has an essential function in GC B cells to sustain the GC response. In its absence, the GC reaction and production of high-affinity antibody is severely impaired. Mechanistically, HuR affects the transcriptome qualitatively and quantitatively. The expression and splicing patterns of hundreds of genes are altered in the absence of HuR. Among these genes, HuR is required for the expression of Myc and a Myc-dependent transcriptional program that controls GC B cell proliferation and Ig somatic hypermutation. Additionally, HuR regulates the splicing and abundance of mRNAs required for entry into and transition through the S phase of the cell cycle, and it modulates a gene signature associated with DNA deamination protecting GC B cells from DNA damage and cell death.
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Affiliation(s)
- Ines C Osma-Garcia
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Inserm UMR1291, CNRS UMR5051, University Paul Sabatier, CHU Purpan, Toulouse, France
| | - Dunja Capitan-Sobrino
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Inserm UMR1291, CNRS UMR5051, University Paul Sabatier, CHU Purpan, Toulouse, France
| | - Mailys Mouysset
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Inserm UMR1291, CNRS UMR5051, University Paul Sabatier, CHU Purpan, Toulouse, France
| | - Sarah E Bell
- Immunology Program, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK
| | - Manuel Lebeurrier
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Inserm UMR1291, CNRS UMR5051, University Paul Sabatier, CHU Purpan, Toulouse, France
| | - Martin Turner
- Immunology Program, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK.
| | - Manuel D Diaz-Muñoz
- Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), Inserm UMR1291, CNRS UMR5051, University Paul Sabatier, CHU Purpan, Toulouse, France. .,Immunology Program, The Babraham Institute, Babraham Research Campus, Cambridge, CB22 3AT, UK.
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9
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Borgonetti V, Coppi E, Galeotti N. Targeting the RNA-Binding Protein HuR as Potential Thera-Peutic Approach for Neurological Disorders: Focus on Amyo-Trophic Lateral Sclerosis (ALS), Spinal Muscle Atrophy (SMA) and Multiple Sclerosis. Int J Mol Sci 2021; 22:ijms221910394. [PMID: 34638733 PMCID: PMC8508990 DOI: 10.3390/ijms221910394] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 01/03/2023] Open
Abstract
The importance of precise co- and post-transcriptional processing of RNA in the regulation of gene expression has become increasingly clear. RNA-binding proteins (RBPs) are a class of proteins that bind single- or double-chain RNA, with different affinities and selectivity, thus regulating the various functions of RNA and the fate of the cells themselves. ELAV (embryonic lethal/abnormal visual system)/Hu proteins represent an important family of RBPs and play a key role in the fate of newly transcribed mRNA. ELAV proteins bind AU-rich element (ARE)-containing transcripts, which are usually present on the mRNA of proteins such as cytokines, growth factors, and other proteins involved in neuronal differentiation and maintenance. In this review, we focused on a member of ELAV/Hu proteins, HuR, and its role in the development of neurodegenerative disorders, with a particular focus on demyelinating diseases.
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10
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Danladi J, Sabir H. Innate immunity, inflammation activation and heat-shock protein in COVID-19 pathogenesis. J Neuroimmunol 2021; 358:577632. [PMID: 34186336 PMCID: PMC8196476 DOI: 10.1016/j.jneuroim.2021.577632] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 05/22/2021] [Accepted: 06/10/2021] [Indexed: 01/08/2023]
Abstract
SARS-CoV-2-induced COVID-19 is a serious pandemic of the 21st century, which has caused a devastating loss of lives and a global economic catastrophe. A successful vaccine against SARS-CoV-2 has suffered a delay due to lack of substantial knowledge about its mechanisms of action. Understanding the innate immune system against SARS-CoV-2 and the role of heat shock proteins' (HSP) inhibiting and resolution of inflammatory pathways may provide information to the low SARS-CoV-2 mortality rates in Africa. In addition, bats being a host to different viruses, including SARS-CoV-2 possess a well specialized IFN-innate antiviral inflammatory response, showing no signs of disease or pro-inflammatory cytokine storm. We discuss the molecular pathways in COVID-19 with a focus on innate immunity, inflammation, HSP responses, and suggest appropriate candidates for therapeutic targets and The contribution of the innate immune system to the efficacy of mRNA or vector based Corona immunizations.
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Affiliation(s)
- Jibrin Danladi
- Department of Neonatology and Pediatric Intensive Care, Children's Hospital University of Bonn, Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.
| | - Hemmen Sabir
- Department of Neonatology and Pediatric Intensive Care, Children's Hospital University of Bonn, Bonn, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany
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11
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Rothamel K, Arcos S, Kim B, Reasoner C, Lisy S, Mukherjee N, Ascano M. ELAVL1 primarily couples mRNA stability with the 3' UTRs of interferon-stimulated genes. Cell Rep 2021; 35:109178. [PMID: 34038724 PMCID: PMC8225249 DOI: 10.1016/j.celrep.2021.109178] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 03/13/2021] [Accepted: 05/04/2021] [Indexed: 12/17/2022] Open
Abstract
Upon pathogen detection, the innate immune system triggers signaling events leading to upregulation of pro-inflammatory and anti-microbial mRNA transcripts. RNA-binding proteins (RBPs) interact with these critical mRNAs and regulate their fates at the post-transcriptional level. One such RBP is ELAVL1. Although significant progress has been made in understanding how embryonic lethal vision-like protein 1 (ELAVL1) regulates mRNAs, its target repertoire and binding distribution within an immunological context remain poorly understood. We overlap four high-throughput approaches to define its context-dependent targets and determine its regulatory impact during immune activation. ELAVL1 transitions from binding overwhelmingly intronic sites to 3′ UTR sites upon immune stimulation of cells, binding previously and newly expressed mRNAs. We find that ELAVL1 mediates the RNA stability of genes that regulate pathways essential to pathogen sensing and cytokine production. Our findings reveal the importance of examining RBP regulatory impact under dynamic transcriptomic events to understand their post-transcriptional regulatory roles within specific biological circuitries. Rothamel et al. show that upon immune activation, the RNA-binding protein ELAVL1 accumulates in the cytoplasm and redistributes from introns to mRNA 3′ UTRs. 3′ UTR binding confers enrichment and transcript stability. Many top-ranking transcripts are interferon-stimulated genes (ISGs), indicating that ELAVL1 is a positive regulator of an innate immune response.
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Affiliation(s)
- Katherine Rothamel
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Sarah Arcos
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Byungil Kim
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Clara Reasoner
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Samantha Lisy
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Neelanjan Mukherjee
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Manuel Ascano
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
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12
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Kumar A, Priyamvada S, Ge Y, Jayawardena D, Singhal M, Anbazhagan AN, Chatterjee I, Dayal A, Patel M, Zadeh K, Saksena S, Alrefai WA, Gill RK, Zadeh M, Zhao N, Mohamadzadeh M, Dudeja PK. A Novel Role of SLC26A3 in the Maintenance of Intestinal Epithelial Barrier Integrity. Gastroenterology 2021; 160:1240-1255.e3. [PMID: 33189700 PMCID: PMC7956241 DOI: 10.1053/j.gastro.2020.11.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 11/02/2020] [Accepted: 11/03/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS The down-regulated in adenoma (DRA) protein, encoded by SLC26A3, a key intestinal chloride anion exchanger, has recently been identified as a novel susceptibility gene for inflammatory bowel disease (IBD). However, the mechanisms underlying the increased susceptibility to inflammation induced by the loss of DRA remain elusive. Compromised barrier is a key event in IBD pathogenesis. The current studies were undertaken to elucidate the impact of DRA deficiency on epithelial barrier integrity and to define underlying mechanisms. METHODS Wild-type and DRA-knockout (KO) mice and crypt-derived colonoids were used as models for intestinal epithelial response. Paracellular permeability was measured by using fluorescein isothiocyanate-dextran flux. Immunoblotting, immunofluorescence, immunohistochemistry, and ribonucleoprotein immunoprecipitation assays were performed. Gut microbiome analysis was conducted to investigate the impact of DRA deficiency on gut microbial communities. RESULTS DRA-KO mice exhibited an increased colonic paracellular permeability with significantly decreased levels of tight junction/adherens junction proteins, including ZO-1, occludin, and E-cadherin. A similar expression pattern of occludin and E-cadherin was observed in colonoids derived from DRA-KO mice and short hairpin RNA-mediated DRA knockdown in Caco-2 cells. Microbial analysis showed gut dysbiosis in DRA-KO mice. However, cohousing studies showed that dysbiosis played only a partial role in maintaining tight junction protein expression. Furthermore, our results showed increased binding of RNA-binding protein CUGBP1 with occludin and E-cadherin genes in DRA-KO mouse colon, suggesting that posttranscriptional mechanisms play a key role in gut barrier dysfunction. CONCLUSIONS To our knowledge, our studies demonstrate a novel role of DRA in maintaining the intestinal epithelial barrier function and potential implications of its dysregulation in IBD pathogenesis.
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Affiliation(s)
- Anoop Kumar
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Shubha Priyamvada
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Yong Ge
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Dulari Jayawardena
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Megha Singhal
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Arivarasu N Anbazhagan
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Ishita Chatterjee
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Aneal Dayal
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Mitul Patel
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Kimia Zadeh
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Seema Saksena
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Waddah A Alrefai
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Mojgan Zadeh
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Ni Zhao
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Mansour Mohamadzadeh
- Department of Infectious Diseases and Immunology and Division of Gastroenterology, Hepatology and Nutrition, Department of Medicine, University of Florida, Gainesville, Florida
| | - Pradeep K Dudeja
- Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois.
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13
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Kumar R, Poria DK, Ray PS. RNA-binding proteins La and HuR cooperatively modulate translation repression of PDCD4 mRNA. J Biol Chem 2021; 296:100154. [PMID: 33288677 PMCID: PMC7949077 DOI: 10.1074/jbc.ra120.014894] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 12/28/2022] Open
Abstract
Posttranscriptional regulation of gene expression plays a critical role in controlling the inflammatory response. An uncontrolled inflammatory response results in chronic inflammation, often leading to tumorigenesis. Programmed cell death 4 (PDCD4) is a proinflammatory tumor-suppressor gene which helps to prevent the transition from chronic inflammation to cancer. PDCD4 mRNA translation is regulated by an interplay between the oncogenic microRNA miR-21 and the RNA-binding protein (RBP) human antigen R (HuR) in response to lipopolysaccharide stimulation, but the role of other regulatory factors remains unknown. Here, we report that the RBP lupus antigen (La) interacts with the 3'-untranslated region of PDCD4 mRNA and prevents miR-21-mediated translation repression. While lipopolysaccharide causes nuclear-cytoplasmic translocation of HuR, it enhances cellular La expression. Remarkably, La and HuR were found to bind cooperatively to the PDCD4 mRNA and mitigate miR-21-mediated translation repression. The cooperative action of La and HuR reduced cell proliferation and enhanced apoptosis, reversing the pro-oncogenic function of miR-21. Together, these observations demonstrate a cooperative interplay between two RBPs, triggered differentially by the same stimulus, which exerts a synergistic effect on PDCD4 expression and thereby helps maintain a balance between inflammation and tumorigenesis.
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Affiliation(s)
- Ravi Kumar
- Department of Biological Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur, Nadia, West Bengal, India
| | - Dipak Kumar Poria
- Department of Biological Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur, Nadia, West Bengal, India
| | - Partho Sarothi Ray
- Department of Biological Sciences, Indian Institute of Science Education and Research, Kolkata, Mohanpur, Nadia, West Bengal, India.
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14
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Simion V, Zhou H, Haemmig S, Pierce JB, Mendes S, Tesmenitsky Y, Pérez-Cremades D, Lee JF, Chen AF, Ronda N, Papotti B, Marto JA, Feinberg MW. A macrophage-specific lncRNA regulates apoptosis and atherosclerosis by tethering HuR in the nucleus. Nat Commun 2020; 11:6135. [PMID: 33262333 PMCID: PMC7708640 DOI: 10.1038/s41467-020-19664-2] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Accepted: 10/26/2020] [Indexed: 01/10/2023] Open
Abstract
Long non-coding RNAs (lncRNAs) are emerging regulators of pathophysiological processes including atherosclerosis. Using RNA-seq profiling of the intima of lesions, here we identify a macrophage-specific lncRNA MAARS (Macrophage-Associated Atherosclerosis lncRNA Sequence). Aortic intima expression of MAARS increases by 270-fold with atherosclerotic progression and decreases with regression by 60%. MAARS knockdown reduces atherosclerotic lesion formation by 52% in LDLR-/- mice, largely independent of effects on lipid profile and inflammation, but rather by decreasing macrophage apoptosis and increasing efferocytosis in the vessel wall. MAARS interacts with HuR/ELAVL1, an RNA-binding protein and important regulator of apoptosis. Overexpression and knockdown studies verified MAARS as a critical regulator of macrophage apoptosis and efferocytosis in vitro, in an HuR-dependent manner. Mechanistically, MAARS knockdown alters HuR cytosolic shuttling, regulating HuR targets such as p53, p27, Caspase-9, and BCL2. These findings establish a mechanism by which a macrophage-specific lncRNA interacting with HuR regulates apoptosis, with implications for a broad range of vascular disease states.
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Affiliation(s)
- Viorel Simion
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Haoyang Zhou
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Department of Cardiology, The Third Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Stefan Haemmig
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jacob B Pierce
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Shanelle Mendes
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Yevgenia Tesmenitsky
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Daniel Pérez-Cremades
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - James F Lee
- The Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Alex F Chen
- Department of Cardiology, The Third Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Nicoletta Ronda
- Department of Food and Drug, University of Parma, Parma, Italy
| | - Bianca Papotti
- Department of Food and Drug, University of Parma, Parma, Italy
| | - Jarrod A Marto
- The Blais Proteomics Center, Dana-Farber Cancer Institute, Boston, MA, USA
- Departments of Cancer Biology and Oncologic Pathology, Dana-Farber Cancer Institute, Boston, MA, USA
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Mark W Feinberg
- Department of Medicine, Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
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15
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Heck T, Ludwig M, Frizzo M, Rasia-Filho A, Homem de Bittencourt PI. Suppressed anti-inflammatory heat shock response in high-risk COVID-19 patients: lessons from basic research (inclusive bats), light on conceivable therapies. Clin Sci (Lond) 2020; 134:1991-2017. [PMID: 32749472 PMCID: PMC7403894 DOI: 10.1042/cs20200596] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/05/2020] [Accepted: 07/24/2020] [Indexed: 12/12/2022]
Abstract
The major risk factors to fatal outcome in COVID-19 patients, i.e., elderliness and pre-existing metabolic and cardiovascular diseases (CVD), share in common the characteristic of being chronic degenerative diseases of inflammatory nature associated with defective heat shock response (HSR). The molecular components of the HSR, the principal metabolic pathway leading to the physiological resolution of inflammation, is an anti-inflammatory biochemical pathway that involves molecular chaperones of the heat shock protein (HSP) family during homeostasis-threatening stressful situations (e.g., thermal, oxidative and metabolic stresses). The entry of SARS coronaviruses in target cells, on the other hand, aggravates the already-jeopardized HSR of this specific group of patients. In addition, cellular counterattack against virus involves interferon (IFN)-mediated inflammatory responses. Therefore, individuals with impaired HSR cannot resolve virus-induced inflammatory burst physiologically, being susceptible to exacerbated forms of inflammation, which leads to a fatal "cytokine storm". Interestingly, some species of bats that are natural reservoirs of zoonotic viruses, including SARS-CoV-2, possess an IFN-based antiviral inflammatory response perpetually activated but do not show any sign of disease or cytokine storm. This is possible because bats present a constitutive HSR that is by far (hundreds of times) more intense and rapid than that of human, being associated with a high core temperature. Similarly in humans, fever is a physiological inducer of HSR while antipyretics, which block the initial phase of inflammation, impair the resolution phase of inflammation through the HSR. These findings offer a rationale for the reevaluation of patient care and fever reduction in SARS, including COVID-19.
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Affiliation(s)
- Thiago Gomes Heck
- Research Group in Physiology, Department of Life Sciences, Regional University of Northwestern Rio Grande do Sul State (UNIJUI), Ijuí, RS, 98700-000 Brazil
- Postgraduate Program in Integral Attention to Health (PPGAIS), Regional University of Northwestern Rio Grande do Sul State (UNIJUI), Ijuí, RS, 98700-000 Brazil
| | - Mirna Stela Ludwig
- Research Group in Physiology, Department of Life Sciences, Regional University of Northwestern Rio Grande do Sul State (UNIJUI), Ijuí, RS, 98700-000 Brazil
- Postgraduate Program in Integral Attention to Health (PPGAIS), Regional University of Northwestern Rio Grande do Sul State (UNIJUI), Ijuí, RS, 98700-000 Brazil
| | - Matias Nunes Frizzo
- Research Group in Physiology, Department of Life Sciences, Regional University of Northwestern Rio Grande do Sul State (UNIJUI), Ijuí, RS, 98700-000 Brazil
- Postgraduate Program in Integral Attention to Health (PPGAIS), Regional University of Northwestern Rio Grande do Sul State (UNIJUI), Ijuí, RS, 98700-000 Brazil
| | - Alberto Antonio Rasia-Filho
- Federal University of Health Sciences of Porto Alegre (UFCSPA), Graduate Program in Biosciences, Porto Alegre, RS, 90050-170 Brazil
| | - Paulo Ivo Homem de Bittencourt
- Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90050-170 Brazil
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16
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Jin Y, Qin X. Comprehensive Analysis of the Roles and Prognostic Value of RNA-Binding Proteins in Head and Neck Squamous Cell Carcinoma. DNA Cell Biol 2020; 39:1789-1798. [PMID: 32716650 DOI: 10.1089/dna.2020.5641] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Head and neck squamous cell carcinoma (HNSCC) is a malignancy with relatively high incidence and poor prognosis. RNA-binding proteins (RBPs) were reported to be dysregulated in multiple cancers and were closely associated with tumor initiation and progression. However, an integrated analysis of the roles of RBPs in HNSCC has not been conducted. In the present study, we obtained transcriptome data and corresponding clinical information of HNSCC patients from The Cancer Genome Atlas database and screened out differentially expressed RBPs between tumor and normal tissues. Subsequently, we utilized a series of bioinformatics analyses to elucidate the potential functions and prognostic value of these RBPs in HNSCC. As a result, a total of 88 aberrantly expressed RBPs were identified, including 63 downregulated and 25 upregulated RBPs. Functional enrichment analysis suggested that the differentially expressed RBPs mainly participated in mRNA metabolic processes, RNA processing, RNA transport, regulation of RNA stability, RNA degradation, and mRNA surveillance pathway. Three RBP genes (NOVA1, EZH2, and RBM24) were determined as prognosis-related hub genes from which EZH2 and NOVA1 were selected to construct a prognostic signature based on LASSO Cox regression algorithm. Further analysis demonstrated that the high-risk patient group stratified by the risk signature has advanced tumor grade and poorer overall survival when compared with low-risk group. Moreover, univariate analysis showed that the risk score, tumor stage, T stage, and N stage were significantly associated with patient overall survival and the multivariate analysis results indicated that the risk score and age were greatly correlated with patient prognosis. Overall, this study provided a comprehensive landscape of RBPs in HNSCC and identified an effective gene signature for predicting the clinical outcomes of HNSCC patient, which may contribute to clinical decision making and individualized cancer treatment.
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Affiliation(s)
- Yu Jin
- Department of General Dentistry, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China.,Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, National Clinical Research Center of Stomatology, Shanghai, P.R. China
| | - Xing Qin
- Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, National Clinical Research Center of Stomatology, Shanghai, P.R. China.,Department of Oral and Maxillofacial-Head & Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P.R. China
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17
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GRK2-Dependent HuR Phosphorylation Regulates HIF1α Activation under Hypoxia or Adrenergic Stress. Cancers (Basel) 2020; 12:cancers12051216. [PMID: 32413989 PMCID: PMC7281538 DOI: 10.3390/cancers12051216] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/09/2020] [Accepted: 05/11/2020] [Indexed: 12/18/2022] Open
Abstract
Adaptation to hypoxia is a common feature in solid tumors orchestrated by oxygen-dependent and independent upregulation of the hypoxia-inducible factor-1α (HIF-1α). We unveiled that G protein-coupled receptor kinase (GRK2), known to be overexpressed in certain tumors, fosters this hypoxic pathway via phosphorylation of the mRNA-binding protein HuR, a central HIF-1α modulator. GRK2-mediated HuR phosphorylation increases the total levels and cytoplasmic shuttling of HuR in response to hypoxia, and GRK2-phosphodefective HuR mutants show defective cytosolic accumulation and lower binding to HIF-1α mRNA in hypoxic Hela cells. Interestingly, enhanced GRK2 and HuR expression correlate in luminal breast cancer patients. GRK2 also promotes the HuR/HIF-1α axis and VEGF-C accumulation in normoxic MCF7 breast luminal cancer cells and is required for the induction of HuR/HIF1-α in response to adrenergic stress. Our results point to a relevant role of the GRK2/HuR/HIF-1α module in the adaptation of malignant cells to tumor microenvironment-related stresses.
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18
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Majumder M, Palanisamy V. RNA binding protein FXR1-miR301a-3p axis contributes to p21WAF1 degradation in oral cancer. PLoS Genet 2020; 16:e1008580. [PMID: 31940341 PMCID: PMC6986764 DOI: 10.1371/journal.pgen.1008580] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 01/28/2020] [Accepted: 12/20/2019] [Indexed: 12/12/2022] Open
Abstract
RNA-binding proteins (RBPs) associate with the primary, precursor, and mature microRNAs, which in turn control post-transcriptional gene regulation. Here, by small RNAseq, we show that RBP FXR1 controls the expression of a subset of mature miRNAs, including highly expressed miR301a-3p in oral cancer cells. We also confirm that FXR1 controls the stability of miR301a-3p. Exoribonuclease PNPT1 degrades miR301a-3p in the absence of FXR1 in oral cancer cells, and the degradation is rescued in the FXR1 and PNPT1 co-knockdown cells. In vitro, we show that PNPT1 is unable to bind and degrade the miRNA once the FXR1-miRNA complex forms. Both miR301a-3p and FXR1 cooperatively target the 3'-UTR of p21 mRNA to promote its degradation. Thus, our work illustrates the unique role of FXR1 that is critical for the stability of a subset of mature miRNAs or at least miR301a-3p to target p21 in oral cancer.
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Affiliation(s)
- Mrinmoyee Majumder
- Department of Biochemistry and Molecular Biology, College of Medicine, Medical University of South Carolina, Charleston, SC, United States of America
| | - Viswanathan Palanisamy
- Department of Biochemistry and Molecular Biology, College of Medicine, Medical University of South Carolina, Charleston, SC, United States of America
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19
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Li F, Chen J, Leier A, Marquez-Lago T, Liu Q, Wang Y, Revote J, Smith AI, Akutsu T, Webb GI, Kurgan L, Song J. DeepCleave: a deep learning predictor for caspase and matrix metalloprotease substrates and cleavage sites. Bioinformatics 2019; 36:1057-1065. [PMID: 31566664 PMCID: PMC8215920 DOI: 10.1093/bioinformatics/btz721] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 08/13/2019] [Accepted: 09/25/2019] [Indexed: 01/31/2023] Open
Abstract
MOTIVATION Proteases are enzymes that cleave target substrate proteins by catalyzing the hydrolysis of peptide bonds between specific amino acids. While the functional proteolysis regulated by proteases plays a central role in the 'life and death' cellular processes, many of the corresponding substrates and their cleavage sites were not found yet. Availability of accurate predictors of the substrates and cleavage sites would facilitate understanding of proteases' functions and physiological roles. Deep learning is a promising approach for the development of accurate predictors of substrate cleavage events. RESULTS We propose DeepCleave, the first deep learning-based predictor of protease-specific substrates and cleavage sites. DeepCleave uses protein substrate sequence data as input and employs convolutional neural networks with transfer learning to train accurate predictive models. High predictive performance of our models stems from the use of high-quality cleavage site features extracted from the substrate sequences through the deep learning process, and the application of transfer learning, multiple kernels and attention layer in the design of the deep network. Empirical tests against several related state-of-the-art methods demonstrate that DeepCleave outperforms these methods in predicting caspase and matrix metalloprotease substrate-cleavage sites. AVAILABILITY AND IMPLEMENTATION The DeepCleave webserver and source code are freely available at http://deepcleave.erc.monash.edu/. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
| | | | - André Leier
- Department of Genetics, USA,Department of Cell, Developmental and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Tatiana Marquez-Lago
- Department of Genetics, USA,Department of Cell, Developmental and Integrative Biology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Quanzhong Liu
- College of Information Engineering, Northwest A&F University, Yangling 712100, China
| | - Yanze Wang
- College of Information Engineering, Northwest A&F University, Yangling 712100, China
| | - Jerico Revote
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - A Ian Smith
- Monash Biomedicine Discovery Institute and Department of Biochemistry and Molecular Biology, Monash University, Melbourne, VIC 3800, Australia
| | - Tatsuya Akutsu
- Bioinformatics Center, Institute for Chemical Research, Kyoto University, Kyoto 611-0011, Japan
| | - Geoffrey I Webb
- Monash Centre for Data Science, Faculty of Information Technology, Monash University, Melbourne, VIC 3800, Australia
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20
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Terasaka T, Kim T, Dave H, Gangapurkar B, Nicholas DA, Muñoz O, Terasaka E, Li D, Lawson MA. The RNA-Binding Protein ELAVL1 Regulates GnRH Receptor Expression and the Response to GnRH. Endocrinology 2019; 160:1999-2014. [PMID: 31188427 PMCID: PMC6660905 DOI: 10.1210/en.2019-00203] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 06/04/2019] [Indexed: 01/11/2023]
Abstract
Gonadotropin secretion, which is elicited by GnRH stimulation of the anterior pituitary gonadotropes, is a critical feature of reproductive control and the maintenance of fertility. In addition, activation of the GnRH receptor (GnRHR) regulates transcription and translation of multiple factors that regulate the signaling response and synthesis of gonadotropins. GnRH stimulation results in a broad redistribution of mRNA between active and inactive polyribosomes within the cell, but the mechanism of redistribution is not known. The RNA-binding protein embryonic lethal, abnormal vision, Drosophila-like 1 (ELAVL1) binds to AU-rich elements in mRNA and is one of the most abundant mRNA-binding proteins in eukaryotic cells. It is known to serve as a core component of RNA-binding complexes that direct the fate of mRNA. In LβT2 gonadotropes, we showed that ELAVL1 binds to multiple mRNAs encoding factors that are crucial for gonadotropin synthesis and release. Association with some mRNAs is GnRH sensitive but does not correlate with abundance of binding. We also showed MAPK-dependent changes in intracellular localization of ELAVL1 in response to GnRH stimulation. Knockdown of ELAVL1 gene expression resulted in reduced Lhb and Gnrhr mRNA levels, reduced cell surface expression of GnRHR, and reduced LH secretion in response to GnRH stimulation. Overall, these observations not only support the role of ELAVL1 in GnRHR-mediated regulation of gene expression and LH secretion but also indicate that other factors may contribute to the precise fate of mRNA in response to GnRH stimulation of gonadotropes.
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Affiliation(s)
- Tomohiro Terasaka
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
| | - Taeshin Kim
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
| | - Hiral Dave
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
| | - Bhakti Gangapurkar
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
| | - Dequina A Nicholas
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
| | - Oscar Muñoz
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
| | - Eri Terasaka
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
| | - Danmei Li
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
| | - Mark A Lawson
- Department of Reproductive Medicine, University of California, San Diego, La Jolla, California
- Correspondence: Mark A. Lawson, PhD, University of California, San Diego, Department of Obstetrics, Gynecology, and Reproductive Sciences, Mail Code 0674, 9500 Gilman Drive, La Jolla, California 92093. E-mail:
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Human antigen R protein modulates vascular endothelial growth factor expression in human corneal epithelial cells under hypoxia. J Formos Med Assoc 2019; 119:359-366. [PMID: 31262614 DOI: 10.1016/j.jfma.2019.06.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/20/2019] [Accepted: 06/14/2019] [Indexed: 01/23/2023] Open
Abstract
PURPOSE Corneal avascularity is critical for corneal transparency; therefore, a tailored process has been presumed to minimize corneal neovascularization (NV). In most cell types, the transcription of vascular endothelial growth factor (VEGF) is up-regulated, and the stability of VEGF mRNA is sustained by human antigen R (HuR) during hypoxia; however, whether such response applies to corneal epithelial cells is unclear. METHODS Human corneal epithelial cells (HCECs) and MCF-7 cells that serves as the control were incubated under 0.5% oxygen, and the levels of VEGF and HuR were examined time-dependently. The alteration of HuR was also examined in vivo using the closed-eye contact lens-induced corneal neovascularization rabbit model and immunohistochemistry. Additionally, the expression of HuR was modulated by transfection of plasmids encoding HuR or siRNA targeting HuR to validate the role of HuR in VEGF expression. RESULTS We found that, unlike in control cells, the level of VEGF was not up-regulated, and the HuR expression was declined in HCECs following hypoxia. The HuR immunostaining intensities were decreased in corneal epithelial cells of rabbits wearing contact lenses. In addition, HuR overexpression restored the ability of HCECs to up-regulate VEGF under hypoxia; however, knockdown of HuR suppressed hypoxia-induced VEGF in control cells but did not further decrease VEGF in HCECs. These findings suggest that HCECs may modulate HuR to suppress hypoxia-mediated up-regulation of VEGF. CONCLUSION Our study revealed a distinct regulation of VEGF via HuR in HCECs following hypoxia, which likely contributes to minimizing corneal NV and/or maintenance of corneal avascularity.
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22
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Guha A, Ahuja D, Das Mandal S, Parasar B, Deyasi K, Roy D, Sharma V, Willard B, Ghosh A, Ray PS. Integrated Regulation of HuR by Translation Repression and Protein Degradation Determines Pulsatile Expression of p53 Under DNA Damage. iScience 2019; 15:342-359. [PMID: 31103853 PMCID: PMC6548907 DOI: 10.1016/j.isci.2019.05.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/20/2018] [Accepted: 05/01/2019] [Indexed: 12/21/2022] Open
Abstract
Expression of tumor suppressor p53 is regulated at multiple levels, disruption of which often leads to cancer. We have adopted an approach combining computational systems modeling with experimental validation to elucidate the translation regulatory network that controls p53 expression post DNA damage. The RNA-binding protein HuR activates p53 mRNA translation in response to UVC-induced DNA damage in breast carcinoma cells. p53 and HuR levels show pulsatile change post UV irradiation. The computed model fitted with the observed pulse of p53 and HuR only when hypothetical regulators of synthesis and degradation of HuR were incorporated. miR-125b, a UV-responsive microRNA, was found to represses the translation of HuR mRNA. Furthermore, UV irradiation triggered proteasomal degradation of HuR mediated by an E3-ubiquitin ligase tripartite motif-containing 21 (TRIM21). The integrated action of miR-125b and TRIM21 constitutes an intricate control system that regulates pulsatile expression of HuR and p53 and determines cell viability in response to DNA damage.
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Affiliation(s)
- Abhishek Guha
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Deepika Ahuja
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Sukhen Das Mandal
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Bibudha Parasar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Krishanu Deyasi
- Department of Mathematics and Statistics, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Debadrita Roy
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Vasundhara Sharma
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Belinda Willard
- Proteomics and Metabolomics Core, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH 44195, USA
| | - Anandamohan Ghosh
- Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India
| | - Partho Sarothi Ray
- Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur 741246, West Bengal, India.
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Palanisamy K, Tsai TH, Yu TM, Sun KT, Yu SH, Lin FY, Wang IK, Li CY. RNA-binding protein, human antigen R regulates hypoxia-induced autophagy by targeting ATG7/ATG16L1 expressions and autophagosome formation. J Cell Physiol 2019; 234:7448-7458. [PMID: 30317574 DOI: 10.1002/jcp.27502] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 09/07/2018] [Indexed: 01/01/2023]
Abstract
Autophagy, a prosurvival mechanism offers a protective role during acute kidney injury. We show novel findings on the functional role of RNA binding protein, HuR during hypoxia-induced autophagy in renal proximal tubular cells-2 (HK-2). HK-2 cells showed upregulated expressions of HuR and autophagy-related proteins such as autophagy related 7 (ATG7), autophagy related 16 like 1 (ATG16L1), and LC3II under hypoxia. Increased autophagosome formation was visualized as LC3 puncta in hypoxic cells. Further, short hairpin-RNA-mediated loss of HuR function in HK-2 cells significantly decreased ATG7 and ATG16L1 protein expressions. Bioinformatics prediction revealed HuR motif binding on the coding region of ATG7 and AU-rich element at 3'UTR ATG16L1 messnger RNA (mRNA). The RNA immunoprecipitation study showed that HuR was predominantly associated with ATG7 and ATG16L1 mRNAs under hypoxia. In addition, HuR enhanced autophagosome formation by regulating LC3II expressions. These results show that HuR regulates ATG7 and ATG16L1 expressions and thereby mediate autophagy in HK-2 cells. Importantly, HuR knockdown cells underwent apoptosis during hypoxia as observed through the terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Collectively, these findings show the crucial role of HuR under hypoxia by regulating autophagy and suppressing apoptosis in renal tubular cells.
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Affiliation(s)
- Kalaiselvi Palanisamy
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
| | - Tsung-Hsun Tsai
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- Division of Urology, Department of Surgery, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung, Taiwan
| | - Tung-Min Yu
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- Division of Nephrology, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Kuo-Ting Sun
- Department of Pediatric Dentistry, China Medical University Hospital, Taichung, Taiwan
- School of Dentistry, College of Dentistry, China Medical University, Taichung, Taiwan
| | - Shao-Hua Yu
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- Department of Emergency Medicine, China Medical University Hospital, Taichung, Taiwan
| | - Feng-Yen Lin
- Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Division of Cardiology and Cardiovascular Research Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - I-Kuan Wang
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- Division of Nephrology, China Medical University Hospital, Taichung, Taiwan
- Department of Internal Medicine, China Medical University College of Medicine, Taichung, Taiwan
| | - Chi-Yuan Li
- Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan
- Department of Anesthesiology, China Medical University Hospital, Taichung, Taiwan
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24
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Bruxel MA, Tavares AMV, Zavarize Neto LD, de Souza Borges V, Schroeder HT, Bock PM, Rodrigues MIL, Belló-Klein A, Homem de Bittencourt PI. Chronic whole-body heat treatment relieves atherosclerotic lesions, cardiovascular and metabolic abnormalities, and enhances survival time restoring the anti-inflammatory and anti-senescent heat shock response in mice. Biochimie 2019; 156:33-46. [DOI: 10.1016/j.biochi.2018.09.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2018] [Accepted: 09/26/2018] [Indexed: 12/15/2022]
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25
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Sui X, Yu S, Dou L, Chen X, Li X, Yang J, Su Y, Wang S, Wang F, Li J. miR-291b-3p mediated ROS-induced endothelial cell dysfunction by targeting HUR. Int J Mol Med 2018; 42:2383-2392. [PMID: 30106126 PMCID: PMC6192777 DOI: 10.3892/ijmm.2018.3821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 08/06/2018] [Indexed: 12/04/2022] Open
Abstract
Endothelial dysfunction is an early marker of atherosclerosis. Previous studies have indicated that microRNA (miR)-291b-3p regulates the metabolism of lipids and glucose in the liver via targeting adenosine monophosphate-activated kinase α1 and transcription factor p65. The present study investigated whether miR-291b-3p mediated H2O2-mediated endothelial dysfunction. The level of apoptosis of EOMA mouse endothelial cells was analyzed by terminal deoxynucleotidyl-transferase-mediated dUTP nick end labelling staining. The mRNA levels of miR-291b-3p, intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) were determined by quantitative polymerase chain reaction. The level of phosphorylated extracellular signal-regulated kinase, and levels of B-cell lymphoma 2 (Bcl-2)-associated X protein and Bcl-2 protein were detected by western blot analysis. The treatment of H2O2 induced the apoptosis and increased the mRNA levels of miR-291b-3p, ICAM-1 and VCAM-1 in EOMA cells. It was also demonstrated that the overexpression of miR-291b-3p promoted EOMA cell apoptosis and dysfunction. In contrast, the downregulation of miR-291b-3p rescued the effect of H2O2 on EOMA cell dysfunction. In addition, Hu antigen R (HuR) was identified as a target gene of miR-291b-3p in EOMA cells. The overexpression of HuR reversed the endothelial dysfunction induced by miR-291b-3p mimics. The present study provides novel insight into the critical role of miR-291b-3p on the endothelial dysfunction induced by H2O2. miR-291b-3p may mediate H2O2-induced endothelial dysfunction via targeting HuR.
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Affiliation(s)
- Xiaofang Sui
- Department of Geriatrics, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China
| | - Shuqian Yu
- Department of Geriatrics, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China
| | - Lin Dou
- The Ministry of Health Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing 100730, P.R. China
| | - Xiehui Chen
- Department of Geriatric Cardiovascular Medicine, Shenzhen Sun Yat‑Sen Cardiovascular Hospital, Shenzhen, Guangdong 518112, P.R. China
| | - Xuejie Li
- Department of Geriatrics, Clinical Medical School, Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China
| | - Jun Yang
- Department of Geriatrics, Clinical Medical School, Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China
| | - Yanan Su
- Department of Geriatrics, Clinical Medical School, Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China
| | - Shuyue Wang
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, Jilin, P.R. China
| | - Fengling Wang
- Department of Geriatrics, The First Affiliated Hospital of Jiamusi University, Jiamusi, Heilongjiang 154002, P.R. China
| | - Jian Li
- The Ministry of Health Key Laboratory of Geriatrics, Beijing Hospital, National Center of Gerontology, Beijing 100730, P.R. China
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26
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Miragem AA, Homem de Bittencourt PI. Nitric oxide-heat shock protein axis in menopausal hot flushes: neglected metabolic issues of chronic inflammatory diseases associated with deranged heat shock response. Hum Reprod Update 2018; 23:600-628. [PMID: 28903474 DOI: 10.1093/humupd/dmx020] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 06/28/2017] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Although some unequivocal underlying mechanisms of menopausal hot flushes have been demonstrated in animal models, the paucity of similar approaches in humans impedes further mechanistic outcomes. Human studies might show some as yet unexpected physiological mechanisms of metabolic adaptation that permeate the phase of decreased oestrogen levels in both symptomatic and asymptomatic women. This is particularly relevant because both the severity and time span of hot flushes are associated with increased risk of chronic inflammatory disease. On the other hand, oestrogen induces the expression of heat shock proteins of the 70 kDa family (HSP70), which are anti-inflammatory and cytoprotective protein chaperones, whose expression is modulated by different types of physiologically stressful situations, including heat stress and exercise. Therefore, lower HSP70 expression secondary to oestrogen deficiency increases cardiovascular risk and predisposes the patient to senescence-associated secretory phenotype (SASP) that culminates in chronic inflammatory diseases, such as obesities, type 2 diabetes, neuromuscular and neurodegenerative diseases. OBJECTIVE AND RATIONALE This review focuses on HSP70 and its accompanying heat shock response (HSR), which is an anti-inflammatory and antisenescent pathway whose intracellular triggering is also oestrogen-dependent via nitric oxide (NO) production. The main goal of the manuscript was to show that the vasomotor symptoms that accompany hot flushes may be a disguised clue for important neuroendocrine alterations linking oestrogen deficiency to the anti-inflammatory HSR. SEARCH METHODS Results from our own group and recent evidence on hypothalamic control of central temperature guided a search on PubMed and Google Scholar websites. OUTCOMES Oestrogen elicits rapid production of the vasodilatory gas NO, a powerful activator of HSP70 expression. Whence, part of the protective effects of oestrogen over cardiovascular and neuroendocrine systems is tied to its capacity of inducing the NO-elicited HSR. The hypothalamic areas involved in thermoregulation (infundibular nucleus in humans and arcuate nucleus in other mammals) and whose neurons are known to have their function altered after long-term oestrogen ablation, particularly kisspeptin-neurokinin B-dynorphin neurons, (KNDy) are the same that drive neuroprotective expression of HSP70 and, in many cases, this response is via NO even in the absence of oestrogen. From thence, it is not illogical that hot flushes might be related to an evolutionary adaptation to re-equip the NO-HSP70 axis during the downfall of circulating oestrogen. WIDER IMPLICATIONS Understanding of HSR could shed light on yet uncovered mechanisms of menopause-associated diseases as well as on possible manipulation of HSR in menopausal women through physiological, pharmacological, nutraceutical and prebiotic interventions. Moreover, decreased HSR indices (that can be clinically determined with ease) in perimenopause could be of prognostic value in predicting the moment and appropriateness of starting a HRT.
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Affiliation(s)
- Antônio Azambuja Miragem
- Laboratory of Cellular Physiology, Department of Physiology, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, ICBS, 2nd Floor, Suite 350, Porto Alegre, RS 90050-170, Brazil.,Federal Institute of Education, Science and Technology 'Farroupilha', Rua Uruguai 1675, Santa Rosa, RS 98900-000, Brazil
| | - Paulo Ivo Homem de Bittencourt
- Laboratory of Cellular Physiology, Department of Physiology, Federal University of Rio Grande do Sul, Rua Sarmento Leite 500, ICBS, 2nd Floor, Suite 350, Porto Alegre, RS 90050-170, Brazil
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27
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Clinical Significance and Biological Role of HuR in Head and Neck Carcinomas. DISEASE MARKERS 2018; 2018:4020937. [PMID: 29619127 PMCID: PMC5829322 DOI: 10.1155/2018/4020937] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 11/27/2017] [Indexed: 12/17/2022]
Abstract
Background Hu-antigen R (HuR) is a posttranscriptional regulator of several target mRNAs, implicated in carcinogenesis. This review aims to present the current evidence regarding the biological role and potential clinical significance of HuR in head and neck carcinomas. Methods The existing literature concerning HuR expression and function in head and neck carcinomas is critically presented and summarised. Results HuR is expressed in the majority of the examined samples, showing higher cytoplasmic levels in malignant or premalignant cases. Moreover, HuR modulates several genes implicated in biological processes important for malignant transformation, growth, and invasiveness. HuR seems to be an adverse prognosticator in patients with OSCCs, whereas a correlation with a more aggressive phenotype is reported in several types of carcinomas. Conclusions A consistent role of HuR in the carcinogenesis and progression of head and neck carcinomas is suggested; nevertheless, further studies are warranted to expand the present information.
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28
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Dejure FR, Eilers M. MYC and tumor metabolism: chicken and egg. EMBO J 2017; 36:3409-3420. [PMID: 29127156 DOI: 10.15252/embj.201796438] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 09/16/2017] [Accepted: 09/28/2017] [Indexed: 12/17/2022] Open
Abstract
Transcription factors of the MYC family are deregulated in the majority of all human cancers. Oncogenic levels of MYC reprogram cellular metabolism, a hallmark of cancer development, to sustain the high rate of proliferation of cancer cells. Conversely, cells need to modulate MYC function according to the availability of nutrients, in order to avoid a metabolic collapse. Here, we review recent evidence that the multiple interactions of MYC with cell metabolism are mutual and review mechanisms that control MYC levels and function in response to metabolic stress situations. The main hypothesis we put forward is that regulation of MYC levels is an integral part of the adaptation of cells to nutrient deprivation. Since such mechanisms would be particularly relevant in tumor cells, we propose that-in contrast to growth factor-dependent controls-they are not disrupted during tumorigenesis and that maintaining flexibility of expression is integral to MYC's oncogenic function.
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Affiliation(s)
- Francesca R Dejure
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Würzburg, Germany
| | - Martin Eilers
- Theodor Boveri Institute and Comprehensive Cancer Center Mainfranken, Biocenter, University of Würzburg, Würzburg, Germany
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29
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Lin GL, Ting HJ, Tseng TC, Juang V, Lo YL. Modulation of the mRNA-binding protein HuR as a novel reversal mechanism of epirubicin-triggered multidrug resistance in colorectal cancer cells. PLoS One 2017; 12:e0185625. [PMID: 28968471 PMCID: PMC5624618 DOI: 10.1371/journal.pone.0185625] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 09/15/2017] [Indexed: 01/29/2023] Open
Abstract
HuR (ELAVL1), a RNA-binding protein, plays a key role in posttranscriptional regulation of multidrug resistance (MDR)-related genes. Among various HuR-regulated oncogenic transcripts, the activation of galectin-3/β-catenin survival pathway is critical to induce transcription of cyclin D1, P-glycoprotein (P-gp) and/or multidrug resistance-associated proteins (MRPs). In this study, we aim to elucidate the HuR-regulating pathways related to epirubicin-mediated resistance in human colorectal carcinoma cells. The effects and mechanisms of epirubicin treatment on the expressions of upstream survival signals (e.g., β-catenin) and downstream MDR transporters (e.g., P-gp) and anti-apoptotic pathways (e.g., Bcl-2) were assessed with or without HuR knockdown (siHuR) or overexpression (overHuR; ectopic HuR or pcDNA3/HA-HuR). Our results showed that siHuR decreased transcriptional expressions of galectin-3, β-catenin, cyclin D1, Bcl-2, P-gp, MRP1, and MRP2 in epirubicin-treated colon cancer cells. Consistently, the co-treatment of epirubicin and siHuR diminished the expressions of galectin-3, ß-catenin, c-Myc, P-gp and MRP1. HuR silencing enhanced the intracellular accumulation of epirubicin in colon cancer cells. On the other hand, overHuR abolished such effects. Furthermore, siHuR significantly intensified epirubicin-mediated apoptosis via increasing reactive oxygen species and thus promoted the cytotoxic effect of epirubicin. The combined treatments of siHuR and epirubicin significantly reduced the expression of Bcl-2, but increased the expression of Bax, as well as activity and expression levels of caspase-3 and -9. In contrast, overHuR abrogated these effects. Our findings provide insight into the mechanisms by which siHuR potentiated epirubicin-induced cytotoxicity via inhibiting galectin-3/β-catenin signaling, suppressing MDR transporters and provoking apoptosis. To our best knowledge, this is an innovative investigation linking the post-transcriptional control by HuR silencing to survival signaling repression, efflux transporter reversal and apoptosis induction. Our study thus provides a powerful regimen for circumventing MDR in colon cancer cells.
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Affiliation(s)
- Guan-Liang Lin
- Department of Biological Sciences and Technology, National University of Tainan, Tainan, Taiwan
| | - Huei-Ju Ting
- Department of Biological Sciences and Technology, National University of Tainan, Tainan, Taiwan
| | - Ta-Chien Tseng
- Institute of Bioinformatics and Biosignaling Transduction, National Cheng Kung University, Tainan, Taiwan
| | - Vivian Juang
- Department and Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Yu-Li Lo
- Department and Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
- * E-mail:
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30
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Janakiraman H, House RP, Talwar S, Courtney SM, Hazard ES, Hardiman G, Mehrotra S, Howe PH, Gangaraju V, Palanisamy V. Repression of caspase-3 and RNA-binding protein HuR cleavage by cyclooxygenase-2 promotes drug resistance in oral squamous cell carcinoma. Oncogene 2016; 36:3137-3148. [PMID: 27941877 PMCID: PMC5453834 DOI: 10.1038/onc.2016.451] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 10/17/2016] [Accepted: 10/31/2016] [Indexed: 12/22/2022]
Abstract
A well-studied RNA-binding protein Hu Antigen-R (HuR), controls post-transcriptional gene regulation and undergoes stress-activated caspase-3 dependent cleavage in cancer cells. The cleavage products of HuR are known to promote cell death however, the underlying molecular mechanisms facilitating caspase-3 activation and HuR cleavage remains unknown. Here, we show that HuR cleavage associated with active caspase-3 in oral cancer cells treated with ionizing radiation and chemotherapeutic drug, paclitaxel. We determined that oral cancer cells overexpressing cyclooxygenase-2 (COX-2) limited the cleavage of caspase-3 and HuR, which reduced the rate of cell death in paclitaxel resistant oral cancer cells. Specific inhibition of COX-2 by celecoxib, promoted apoptosis through activation of caspase-3 and cleavage of HuR in paclitaxel-resistant oral cancer cells, both in vitro and in vivo. In addition, oral cancer cells overexpressing cellular HuR increased the half-life of COX-2 mRNA, promoted COX-2 protein expression and exhibited enhanced tumor growth in vivo in comparison with cells expressing a cleavable form of HuR. Finally, our ribonucleoprotein immunoprecipitation and sequencing (RIP-seq) analyses of HuR in oral cancer cells treated with ionizing radiation (IR), determined that HuR cleavage product-1 (HuR-CP1) bound and promoted the expression of mRNAs encoding proteins involved in apoptosis. Our results indicated that, cellular non-cleavable HuR controls COX-2 mRNA expression and enzymatic activity. In addition, overexpressed COX-2 protein repressed the cleavage of caspase-3 and HuR to promote drug resistance and tumor growth. Altogether, our observations support the use of the COX-2 inhibitor celecoxib, in combination with paclitaxel, for the management of paclitaxel resistant oral cancer cells.
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Affiliation(s)
- H Janakiraman
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - R P House
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - S Talwar
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - S M Courtney
- Center for Genomics Medicine, Medical University of South Carolina, Charleston, SC, USA.,Department of Pathology, Medical University of South Carolina, Charleston, SC, USA
| | - E S Hazard
- Center for Genomics Medicine, Medical University of South Carolina, Charleston, SC, USA.,Library Science and Informatics, Medical University of South Carolina, Charleston, SC, USA
| | - G Hardiman
- Center for Genomics Medicine, Medical University of South Carolina, Charleston, SC, USA.,Departments of Medicine and Public Health, Medical University of South Carolina, Charleston, SC, USA
| | - S Mehrotra
- Department of Surgery, Medical University of South Carolina, Charleston, SC, USA
| | - P H Howe
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - V Gangaraju
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
| | - V Palanisamy
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA.,Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, USA
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31
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Leite JSM, Cruzat VF, Krause M, Homem de Bittencourt PI. Physiological regulation of the heat shock response by glutamine: implications for chronic low-grade inflammatory diseases in age-related conditions. ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s41110-016-0021-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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32
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House RP, Talwar S, Hazard ES, Hill EG, Palanisamy V. RNA-binding protein CELF1 promotes tumor growth and alters gene expression in oral squamous cell carcinoma. Oncotarget 2016; 6:43620-34. [PMID: 26498364 PMCID: PMC4791255 DOI: 10.18632/oncotarget.6204] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 10/09/2015] [Indexed: 12/15/2022] Open
Abstract
The RNA binding protein CELF1 (also known as CUGBP1) is emerging as a critical regulator of cancer cell proliferation and apoptosis. Here, to provide a global prospective of CELF1 regulation of oral squamous cell carcinoma, we performed RNA-sequencing in oral cancer cells and CELF1 overexpression analysis in non-malignant human oral keratinocytes. Our approaches identified 1283 mRNAs differentially regulated as a function of CELF1 expression and more importantly CELF1 promoted alternative splicing of several target pre-mRNAs, which are known to be involved in various cancer biological processes. Overexpression of CELF1 in non-malignant human oral keratinocytes protected cells against oxidative damage and altered gene expression patterns. Finally, we provide evidence that reduction of CELF1 protein using a xenograft tumorigenesis mouse model decreased tumor growth. Altogether, these data provided a comprehensive view of the CELF1 mRNA regulatory network in oral cancer and suggests that CELF1 and/or its target mRNAs are viable candidates for therapeutic intervention.
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Affiliation(s)
- Reniqua P House
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - Sudha Talwar
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
| | - E Starr Hazard
- Division of Bioinformatics, Medical University of South Carolina, Charleston, SC, USA
| | - Elizabeth G Hill
- Department of Public Health Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Viswanathan Palanisamy
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
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33
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Majumder M, House R, Palanisamy N, Qie S, Day TA, Neskey D, Diehl JA, Palanisamy V. RNA-Binding Protein FXR1 Regulates p21 and TERC RNA to Bypass p53-Mediated Cellular Senescence in OSCC. PLoS Genet 2016; 12:e1006306. [PMID: 27606879 PMCID: PMC5015924 DOI: 10.1371/journal.pgen.1006306] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 08/17/2016] [Indexed: 12/14/2022] Open
Abstract
RNA-binding proteins (RBP) regulate numerous aspects of co- and post-transcriptional gene expression in cancer cells. Here, we demonstrate that RBP, fragile X-related protein 1 (FXR1), plays an essential role in cellular senescence by utilizing mRNA turnover pathway. We report that overexpressed FXR1 in head and neck squamous cell carcinoma targets (G-quadruplex (G4) RNA structure within) both mRNA encoding p21 (Cyclin-Dependent Kinase Inhibitor 1A (CDKN1A, Cip1) and the non-coding RNA Telomerase RNA Component (TERC), and regulates their turnover to avoid senescence. Silencing of FXR1 in cancer cells triggers the activation of Cyclin-Dependent Kinase Inhibitors, p53, increases DNA damage, and ultimately, cellular senescence. Overexpressed FXR1 binds and destabilizes p21 mRNA, subsequently reduces p21 protein expression in oral cancer cells. In addition, FXR1 also binds and stabilizes TERC RNA and suppresses the cellular senescence possibly through telomerase activity. Finally, we report that FXR1-regulated senescence is irreversible and FXR1-depleted cells fail to form colonies to re-enter cellular proliferation. Collectively, FXR1 displays a novel mechanism of controlling the expression of p21 through p53-dependent manner to bypass cellular senescence in oral cancer cells.
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Affiliation(s)
- Mrinmoyee Majumder
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Reniqua House
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Nallasivam Palanisamy
- Department of Urology, Henry Ford Health System, Vattikuti Urology Institute, Detroit, Michigan, United States of America
| | - Shuo Qie
- Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Terrence A. Day
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - David Neskey
- Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - J. Alan Diehl
- Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, United States of America
| | - Viswanathan Palanisamy
- Department of Oral Health Sciences and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, South Carolina, United States of America
- Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, United States of America
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Romeo C, Weber MC, Zarei M, DeCicco D, Chand SN, Lobo AD, Winter JM, Sawicki JA, Sachs JN, Meisner-Kober N, Yeo CJ, Vadigepalli R, Tykocinski ML, Brody JR. HuR Contributes to TRAIL Resistance by Restricting Death Receptor 4 Expression in Pancreatic Cancer Cells. Mol Cancer Res 2016; 14:599-611. [PMID: 27053682 PMCID: PMC5312260 DOI: 10.1158/1541-7786.mcr-15-0448] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/22/2016] [Indexed: 12/11/2022]
Abstract
UNLABELLED Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal cancers, in part, due to resistance to both conventional and targeted therapeutics. TRAIL directly induces apoptosis through engagement of cell surface Death Receptors (DR4 and DR5), and has been explored as a molecular target for cancer treatment. Clinical trials with recombinant TRAIL and DR-targeting agents, however, have failed to show overall positive outcomes. Herein, we identify a novel TRAIL resistance mechanism governed by Hu antigen R (HuR, ELAV1), a stress-response protein abundant and functional in PDA cells. Exogenous HuR overexpression in TRAIL-sensitive PDA cell lines increases TRAIL resistance whereas silencing HuR in TRAIL-resistant PDA cells, by siRNA oligo-transfection, decreases TRAIL resistance. PDA cell exposure to soluble TRAIL induces HuR translocation from the nucleus to the cytoplasm. Furthermore, it is demonstrated that HuR interacts with the 3'-untranslated region (UTR) of DR4 mRNA. Pre-treatment of PDA cells with MS-444 (Novartis), an established small molecule inhibitor of HuR, substantially increased DR4 and DR5 cell surface levels and enhanced TRAIL sensitivity, further validating HuR's role in affecting TRAIL apoptotic resistance. NanoString analyses on the transcriptome of TRAIL-exposed PDA cells identified global HuR-mediated increases in antiapoptotic processes. Taken together, these data extend HuR's role as a key regulator of TRAIL-induced apoptosis. IMPLICATIONS Discovery of an important new HuR-mediated TRAIL resistance mechanism suggests that tumor-targeted HuR inhibition increases sensitivity to TRAIL-based therapeutics and supports their re-evaluation as an effective treatment for PDA patients. Mol Cancer Res; 14(7); 599-611. ©2016 AACR.
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Affiliation(s)
- Carmella Romeo
- Division of Surgical Research, Department of Surgery, Jefferson Pancreas, Biliary, and Related Cancer Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania. Department of Pathology, Anatomy, and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Matthew C Weber
- Department of Pathology, Anatomy, and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Mahsa Zarei
- Division of Surgical Research, Department of Surgery, Jefferson Pancreas, Biliary, and Related Cancer Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Danielle DeCicco
- Department of Pathology, Anatomy, and Cell Biology, Daniel Baugh Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Saswati N Chand
- Division of Surgical Research, Department of Surgery, Jefferson Pancreas, Biliary, and Related Cancer Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Angie D Lobo
- Department of Pathology, Anatomy, and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jordan M Winter
- Division of Surgical Research, Department of Surgery, Jefferson Pancreas, Biliary, and Related Cancer Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Janet A Sawicki
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania
| | - Jonathan N Sachs
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, Minnesota
| | | | - Charles J Yeo
- Division of Surgical Research, Department of Surgery, Jefferson Pancreas, Biliary, and Related Cancer Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Rajanikanth Vadigepalli
- Department of Pathology, Anatomy, and Cell Biology, Daniel Baugh Institute, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Mark L Tykocinski
- Department of Pathology, Anatomy, and Cell Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Jonathan R Brody
- Division of Surgical Research, Department of Surgery, Jefferson Pancreas, Biliary, and Related Cancer Center, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania.
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Prislei S, Martinelli E, Zannoni GF, Petrillo M, Filippetti F, Mariani M, Mozzetti S, Raspaglio G, Scambia G, Ferlini C. Role and prognostic significance of the epithelial-mesenchymal transition factor ZEB2 in ovarian cancer. Oncotarget 2016; 6:18966-79. [PMID: 26136338 PMCID: PMC4662468 DOI: 10.18632/oncotarget.3943] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 05/05/2015] [Indexed: 12/12/2022] Open
Abstract
ZEB2 is a key factor in epithelial-mesenchymal transition (EMT), a program controlling cell migration in embryonic development and adult tissue homeostasis. We demonstrated a role of ZEB2 in migration and anchorage-independent cell growth in ovarian cancer, as shown by ZEB2 silencing. We found that the RNA-binding protein HuR bound the 3′UTR of ZEB2 mRNA, acting as a positive regulator of ZEB2 protein expression. In Hey ovarian cell line, HuR silencing decreased ZEB2 and ZEB1 nuclear expression and impaired migration. In hypoglycemic conditions ZEB2 expression decreased, along with ZEB1, vimentin and cytoplasmic HuR, and a reduced cellular migration ability was observed. Analysis of ZEB2 and HuR expression in ovarian cancers revealed that nuclear ZEB2 is localized in tumor leading edge and co-localizes with cytoplasmic HuR. In a series of 143 ovarian cancer patients high expression of ZEB2 mRNA significantly correlated with a poor prognosis in term of both overall survival and progression- free survival. Moreover, at immunohistochemical evaluation, we found that prognostic significance of ZEB2 protein relies on its nuclear expression and co-localization with cytoplasmic HuR. In conclusion our findings indicated that nuclear ZEB2 may enhance progression of EMT transition and acquisition of an aggressive phenotype in ovarian cancer.
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Affiliation(s)
- Silvia Prislei
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy
| | - Enrica Martinelli
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy
| | - Gian Franco Zannoni
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy.,Department of Pathology, Catholic University of the Sacred Heart, Rome, Italy
| | - Marco Petrillo
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy
| | - Flavia Filippetti
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy
| | - Marisa Mariani
- Reproductive Tumor Biology Research, Biomedical Lab, Department of Obstetrics and Gynecology, Danbury Hospital, Danbury, CT, USA
| | - Simona Mozzetti
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy
| | - Giuseppina Raspaglio
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy
| | - Giovanni Scambia
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy
| | - Cristiano Ferlini
- Department of Obstetrics and Gynecology, Catholic University of the Sacred Heart, Rome, Italy.,Reproductive Tumor Biology Research, Biomedical Lab, Department of Obstetrics and Gynecology, Danbury Hospital, Danbury, CT, USA
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Tsai JS, Chao CH, Lin LY. Cadmium Activates Multiple Signaling Pathways That Coordinately Stimulate Akt Activity to Enhance c-Myc mRNA Stability. PLoS One 2016; 11:e0147011. [PMID: 26751215 PMCID: PMC4709241 DOI: 10.1371/journal.pone.0147011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 12/28/2015] [Indexed: 01/07/2023] Open
Abstract
Cadmium is a known environmental carcinogen. Exposure of Cd leads to the activation of several proto-oncogenes in cells. We investigated here the mechanism of c-Myc expression in hepatic cells under Cd treatment. The c-Myc protein and mRNA levels increased in dose- and time-dependent manners in HepG2 cells with Cd treatment. This increase was due to an increase in c-Myc mRNA stability. To explore the mechanism involved in enhancing the mRNA stability, several cellular signaling factors that evoked by Cd treatment were analyzed. PI3K, p38, ERK and JNK were activated by Cd. However, ERK did not participate in the Cd-induced c-Myc expression. Further analysis revealed that mTORC2 was a downstream factor of p38. PI3K, JNK and mTORC2 coordinately activated Akt. Akt was phosphorylated at Thr450 in the untreated cells. Cd treatment led to additional phosphorylation at Thr308 and Ser473. Blocking any of the three signaling factors resulted in the reduction of phosphorylation level at all three Akt sites. The activated Akt phosphorylated Foxo1 and allowed the modified protein to translocate into the cytoplasm. We conclude that Cd-induced accumulation of c-Myc requires the activation of several signaling pathways. The signals act coordinately for Akt activation and drive the Foxo1 from the nucleus to the cytoplasm. Reduction of Foxo1 in the nucleus reduces the transcription of its target genes that may affect c-Myc mRNA stability, resulting in a higher accumulation of the c-Myc proteins.
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Affiliation(s)
- Jia-Shiuan Tsai
- Institute of Molecular and Cellular Biology, and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC
| | - Cheng-Han Chao
- Division of Nephrology, Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsinchu, Taiwan, ROC
| | - Lih-Yuan Lin
- Institute of Molecular and Cellular Biology, and Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan, ROC
- * E-mail:
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Mihailovich M, Bremang M, Spadotto V, Musiani D, Vitale E, Varano G, Zambelli F, Mancuso FM, Cairns DA, Pavesi G, Casola S, Bonaldi T. miR-17-92 fine-tunes MYC expression and function to ensure optimal B cell lymphoma growth. Nat Commun 2015; 6:8725. [PMID: 26555894 PMCID: PMC4667639 DOI: 10.1038/ncomms9725] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 09/22/2015] [Indexed: 01/07/2023] Open
Abstract
The synergism between c-MYC and miR-17-19b, a truncated version of the miR-17-92 cluster, is well-documented during tumor initiation. However, little is known about miR-17-19b function in established cancers. Here we investigate the role of miR-17-19b in c-MYC-driven lymphomas by integrating SILAC-based quantitative proteomics, transcriptomics and 3′ untranslated region (UTR) analysis upon miR-17-19b overexpression. We identify over one hundred miR-17-19b targets, of which 40% are co-regulated by c-MYC. Downregulation of a new miR-17/20 target, checkpoint kinase 2 (Chek2), increases the recruitment of HuR to c-MYC transcripts, resulting in the inhibition of c-MYC translation and thus interfering with in vivo tumor growth. Hence, in established lymphomas, miR-17-19b fine-tunes c-MYC activity through a tight control of its function and expression, ultimately ensuring cancer cell homeostasis. Our data highlight the plasticity of miRNA function, reflecting changes in the mRNA landscape and 3′ UTR shortening at different stages of tumorigenesis. The synergism between c-MYC and miR-17-19b plays an important role in lymphoma initiation. In this study, the authors identify a panel of targets co-regulated by miR-17-19b and in MYC-driven lymphoma and unravel the molecular mechanism through which miR-17-19b inhibits MYC translation.
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Affiliation(s)
- Marija Mihailovich
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, Milan 20139, Italy
| | - Michael Bremang
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, Milan 20139, Italy
| | - Valeria Spadotto
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, Milan 20139, Italy
| | - Daniele Musiani
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, Milan 20139, Italy
| | - Elena Vitale
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, Milan 20139, Italy
| | - Gabriele Varano
- Units of Genetics of B cells and lymphomas, IFOM, FIRC Institute of Molecular Oncology Foundation, Milan 20139, Italy
| | | | - Francesco M Mancuso
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, Milan 20139, Italy
| | - David A Cairns
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, Milan 20139, Italy
| | - Giulio Pavesi
- Department of Biosciences, Milan University, Milan 20133, Italy
| | - Stefano Casola
- Units of Genetics of B cells and lymphomas, IFOM, FIRC Institute of Molecular Oncology Foundation, Milan 20139, Italy
| | - Tiziana Bonaldi
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello 16, Milan 20139, Italy
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Bai D, Ge L, Gao Y, Lu X, Wang H, Yang G. Cytoplasmic translocation of HuR contributes to angiotensin II induced cardiac fibrosis. Biochem Biophys Res Commun 2015; 463:1273-7. [DOI: 10.1016/j.bbrc.2015.06.101] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Accepted: 06/14/2015] [Indexed: 01/19/2023]
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Kemmerer K, Weigand JE. Hypoxia reduces MAX expression in endothelial cells by unproductive splicing. FEBS Lett 2014; 588:4784-90. [DOI: 10.1016/j.febslet.2014.11.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 10/20/2014] [Accepted: 11/05/2014] [Indexed: 10/24/2022]
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Jeon YJ, Kim HS, Song KS, Han HJ, Park SH, Chang W, Lee MY. Protective effect of dieckol against chemical hypoxia-induced cytotoxicity in primary cultured mouse hepatocytes. Drug Chem Toxicol 2014; 38:180-7. [DOI: 10.3109/01480545.2014.928719] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Jeon YJ, Song KS, Han HJ, Park SH, Chang W, Lee MY. Rosmarinic acid inhibits chemical hypoxia-induced cytotoxicity in primary cultured rat hepatocytes. Arch Pharm Res 2014; 37:907-15. [PMID: 24085626 DOI: 10.1007/s12272-013-0234-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 08/06/2013] [Indexed: 12/21/2022]
Abstract
We examine the effect of rosmarinic acid (RA) in chemical hypoxia-induced injury in rat hepatocytes. Cell viability was significantly decreased by cobalt chloride (CoCl2), a well-known hypoxia mimetic agent in a time- and dose- dependent manner. RA pretreatment before exposure to CoCl2 significantly attenuated the CoCl2-induced decrease of cell viability. Additionally, pretreatment with RA potentiated the decrease of Bcl-2 expression and attenuated the increase of Caspase-3 expression by CoCl2. CoCl2 treatment resulted in an increase of intracellular ROS generation, which is inhibited by RA or N-acetyl-cysteine (NAC, a ROS scavenger), and p38MAPK phosphorylation, which is also blocked by RA or NAC. CoCl2-induced increase of Bax/Bcl-2 ratio and Caspase-3 expression was attenuated by RA, NAC and SB203580 (p38MAPK inhibitor). CoCl2-induced decrease of cell viability was also attenuated by RA, NAC and SB203580 pretreatment. Additionally, RA inhibited CoCl2-induced COX-2 expression and prostaglandin E2 (PGE2) secretion. Similar to the effect of RA, both NAC and NS-398 (COX-2 inhibitor) blocked CoCl2-induced COX-2 expression and PGE2 secretion. NS-398 attenuated not only CoCl2-induced increase of Bax/Bcl-2 ratio and Caspase-3 expression, but decrease of cell viability. Taken together, RA protects primary cultured rat hepatocytes against CoCl2-induced cell injury through inhibition of ROS-activated p38MAPK and COX-2/PGE2 pathway.
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Affiliation(s)
- Yu Jin Jeon
- Department of Molecular Physiology, College of Pharmacy, Kyungpook National University, Taegu, 702-701, Korea
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Newsholme P, de Bittencourt PIH. The fat cell senescence hypothesis: a mechanism responsible for abrogating the resolution of inflammation in chronic disease. Curr Opin Clin Nutr Metab Care 2014; 17:295-305. [PMID: 24878874 DOI: 10.1097/mco.0000000000000077] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
PURPOSE OF REVIEW Obesity is a chronic inflammatory disease in which the physiological resolution of inflammation is attenuated, leading to low-grade inflammation throughout the body. However, the heat shock response, which is a key component of the physiological response to resolve inflammation, is seriously hampered in adipose tissue and other metabolic organs (e.g. skeletal muscle, liver, pancreatic β-cells) in metabolic diseases. In this review, we hypothesize that adipocyte metabolic stress triggers the onset of fat cell senescence, and companion senescence-associated secretory phenotype (SASP), and that such a scenario is responsible for attenuating the resolution of inflammation. RECENT FINDINGS We shall discuss the role of the heat shock response in the context of the resolution of inflammation and the relevance of heat shock response blockade in chronic inflammatory diseases. Sirtuin-1 is responsible for the induction of heat shock transcription factor-1 mRNA expression and for the stabilization of heat shock transcription factor-1 in a high-profile activity state. However, adipose tissue-emanated SASP depress sirtuin-1 expression, leading adipocytes to a perpetual state of unresolved inflammation, due to a dampening of the heat shock response. SUMMARY The advance of inflammasome-mediated SASP from adipose to other tissues promotes cellular senescence in many other cells of the organism, aggravating obesity-dependent chronic inflammation. Inducers of heat shock response (e.g. heat shock itself, physical exercise and calorie restriction) may efficiently interrupt this vicious cycle and are envisaged as the best and also the most economical treatment for obesity-related chronic diseases.
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Affiliation(s)
- Philip Newsholme
- aSchool of Biomedical Sciences, Curtin Health Innovation Research Institute (CHIRI), Curtin University, Perth, Western Australia, Australia bLaboratory of Cellular Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre cNational Institute of Hormones and Women's Health, Porto Alegre, RS, Brazil
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Talwar S, House R, Sundaramurthy S, Balasubramanian S, Yu H, Palanisamy V. Inhibition of caspases protects mice from radiation-induced oral mucositis and abolishes the cleavage of RNA-binding protein HuR. J Biol Chem 2013; 289:3487-500. [PMID: 24362034 DOI: 10.1074/jbc.m113.504951] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The oral mucosal epithelium is typically insulted during chemotherapy and ionizing radiation (IR) therapy and disposed to mucositis, which creates painful inflammation and ulceration in the oral cavity. Oral mucositis alters gene expression patterns, inhibits cellular growth, and initiates cell death in the oral epithelial compartments. Such alterations are governed by several different factors, including transcription factors, RNA-binding proteins, and microRNAs. IR-induced post-transcriptional regulation of RNA-binding proteins exists but is poorly studied in clinically relevant settings. We herein report that the RNA-binding protein human antigen R (HuR) undergoes cleavage modification by caspase-3 following IR-induced oral mucositis and subsequently promotes the expression of the pro-apoptotic factor BAX (Bcl-2-associated X protein), as well as cell death. Further analyses revealed that the HuR cleavage product-1 (HuR-CP1) directly associates and stabilizes the BAX mRNA and concurrently activates the apoptotic pathway. On the other hand, a noncleavable isoform of HuR promotes the clonogenic capacity of primary oral keratinocytes and decreases the effect of IR-induced cell death. Additionally, specific inhibition of caspase-3 by a compound, NSC321205, increases the clonogenic capacity of primary oral keratinocytes and causes increased basal layer cellularity, thickened mucosa, and elevated epithelial cell growth in the tongues of mice with oral mucositis. This protective effect of NSC321205 is mediated by a decrease in caspase-3 activity and the consequent inhibition of HuR cleavage, which reduces the expression of BAX in mice with IR-induced oral mucositis. Thus, we have identified a new molecular mechanism of HuR in the regulation of mRNA turnover and apoptosis in oral mucositis, and our data suggest that blocking the cleavage of HuR enhances cellular growth in the oral epithelial compartment.
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Affiliation(s)
- Sudha Talwar
- From the Department of Craniofacial Biology and Center for Oral Health Research, College of Dental Medicine, and
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Govindaraju S, Lee BS. Adaptive and maladaptive expression of the mRNA regulatory protein HuR. World J Biol Chem 2013; 4:111-118. [PMID: 24340134 PMCID: PMC3856306 DOI: 10.4331/wjbc.v4.i4.111] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 08/31/2013] [Accepted: 11/05/2013] [Indexed: 02/05/2023] Open
Abstract
The RNA-binding proteins involved in regulation of mRNA post-transcriptional processing and translation control the fates of thousands of mRNA transcripts and basic cellular processes. The best studied of these, HuR, is well characterized as a mediator of mRNA stability and translation, and more recently, as a factor in nuclear functions such as pre-mRNA splicing. Due to HuR’s role in regulating thousands of mRNA transcripts, including those for other RNA-binding proteins, HuR can act as a master regulator of cell survival and proliferation. HuR itself is subject to multiple post-translational modifications including regulation of its nucleocytoplasmic distribution. However, the mechanisms that govern HuR levels in the cell have only recently begun to be defined. These mechanisms are critical to cell health, as it has become clear in recent years that aberrant expression of HuR can lead alternately to decreased cell viability or to promotion of pathological proliferation and invasiveness. HuR is expressed as alternate mRNAs that vary in their untranslated regions, leading to differences in transcript stability and translatability. Multiple transcription factors and modulators of mRNA stability that regulate HuR mRNA expression have been identified. In addition, translation of HuR is regulated by numerous microRNAs, several of which have been demonstrated to have anti-tumor properties due to their suppression of HuR expression. This review summarizes the current state of knowledge of the factors that regulate HuR expression, along with the circumstances under which these factors contribute to cancer and inflammation.
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Frank SB, Miranti CK. Disruption of prostate epithelial differentiation pathways and prostate cancer development. Front Oncol 2013; 3:273. [PMID: 24199173 PMCID: PMC3813973 DOI: 10.3389/fonc.2013.00273] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/18/2013] [Indexed: 12/14/2022] Open
Abstract
One of the foremost problems in the prostate cancer (PCa) field is the inability to distinguish aggressive from indolent disease, which leads to difficult prognoses and thousands of unnecessary surgeries. This limitation stems from the fact that the mechanisms of tumorigenesis in the prostate are poorly understood. Some genetic alterations are commonly reported in prostate tumors, including upregulation of Myc, fusion of Ets genes to androgen-regulated promoters, and loss of Pten. However, the specific roles of these aberrations in tumor initiation and progression are poorly understood. Likewise, the cell of origin for PCa remains controversial and may be linked to the aggressive potential of the tumor. One important clue is that prostate tumors co-express basal and luminal protein markers that are restricted to their distinct cell types in normal tissue. Prostate epithelium contains layer-specific stem cells as well as rare bipotent cells, which can differentiate into basal or luminal cells. We hypothesize that the primary oncogenic cell of origin is a transient-differentiating bipotent cell. Such a cell must maintain tight temporal and spatial control of differentiation pathways, thus increasing its susceptibility for oncogenic disruption. In support of this hypothesis, many of the pathways known to be involved in prostate differentiation can be linked to genes commonly altered in PCa. In this article, we review what is known about important differentiation pathways (Myc, p38MAPK, Notch, PI3K/Pten) in the prostate and how their misregulation could lead to oncogenesis. Better understanding of normal differentiation will offer new insights into tumor initiation and may help explain the functional significance of common genetic alterations seen in PCa. Additionally, this understanding could lead to new methods for classifying prostate tumors based on their differentiation status and may aid in identifying more aggressive tumors.
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Affiliation(s)
- Sander B Frank
- Laboratory of Integrin Signaling and Tumorigenesis, Van Andel Research Institute , Grand Rapids, MI , USA ; Genetics Graduate Program, Michigan State University , East Lansing, MI , USA
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Wang J, Guo Y, Chu H, Guan Y, Bi J, Wang B. Multiple functions of the RNA-binding protein HuR in cancer progression, treatment responses and prognosis. Int J Mol Sci 2013; 14:10015-41. [PMID: 23665903 PMCID: PMC3676826 DOI: 10.3390/ijms140510015] [Citation(s) in RCA: 202] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Revised: 04/22/2013] [Accepted: 04/25/2013] [Indexed: 12/16/2022] Open
Abstract
The human embryonic lethal abnormal vision-like protein, HuR, is a member of the Hu family of RNA-binding proteins. Over the past decade, this ubiquitously expressed protein has been extensively investigated in cancer research because it is involved in the regulation of mRNA stability and translation in many cell types. HuR activity and function is associated with its subcellular distribution, transcriptional regulation, translational and post-translational modifications. HuR regulation of target mRNAs is based on the interaction between the three specific domains of HuR protein and one or several U- or AU-rich elements (AREs) in the untranslated region of target mRNAs. A number of cancer-related transcripts containing AREs, including mRNAs for proto-oncogenes, cytokines, growth factors, and invasion factors, have been characterized as HuR targets. It has been proposed that HuR has a central tumorigenic activity by enabling multiple cancer phenotypes. In this review, we comprehensively survey the existing evidence with regard to the diverse functions of HuR in caner development and progression. The current data also suggest that HuR might be a novel and promising therapeutic target and a marker for treatment response and prognostic evaluation.
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Affiliation(s)
- Jun Wang
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +86-531-5166-5336; Fax: +86-531-5166-6649
| | - Yan Guo
- Department of Outpatient, Military Command of Shandong Province, Jinan 250013, China; E-Mail:
| | - Huili Chu
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
| | - Yaping Guan
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
| | - Jingwang Bi
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
| | - Baocheng Wang
- Department of Oncology, General Hospital, Jinan Command of the People’s Liberation Army, Jinan 250031, China; E-Mails: (H.C.); (Y.G.); (J.B.); (B.W.)
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Liu Y, Conaway L, Rutherford Bethard J, Al-Ayoubi AM, Thompson Bradley A, Zheng H, Weed SA, Eblen ST. Phosphorylation of the alternative mRNA splicing factor 45 (SPF45) by Clk1 regulates its splice site utilization, cell migration and invasion. Nucleic Acids Res 2013; 41:4949-62. [PMID: 23519612 PMCID: PMC3643583 DOI: 10.1093/nar/gkt170] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Alternative mRNA splicing is a mechanism to regulate protein isoform expression and is regulated by alternative splicing factors. The alternative splicing factor 45 (SPF45) is overexpressed in cancer, although few biological effects of SPF45 are known, and few splicing targets have been identified. We previously showed that Extracellular Regulated Kinase 2 (ERK2) phosphorylation of SPF45 regulates cell proliferation and adhesion to fibronectin. In this work, we show that Cdc2-like kinase 1 (Clk1) phosphorylates SPF45 on eight serine residues. Clk1 expression enhanced, whereas Clk1 inhibition reduced, SPF45-induced exon 6 exclusion from Fas mRNA. Mutational analysis of the Clk1 phosphorylation sites on SPF45 showed both positive and negative regulation of splicing, with a net effect of inhibiting SPF45-induced exon 6 exclusion, correlating with reduced Fas mRNA binding. However, Clk1 enhanced SPF45 protein expression, but not mRNA expression, whereas inhibition of Clk1 increased SPF45 degradation through a proteasome-dependent pathway. Overexpression of SPF45 or a phospho-mimetic mutant, but not a phospho-inhibitory mutant, stimulated ovarian cancer cell migration and invasion, correlating with increased fibronectin expression, ERK activation and enhanced splicing and phosphorylation of full-length cortactin. Our results demonstrate for the first time that SPF45 overexpression enhances cell migration and invasion, dependent on biochemical regulation by Clk1.
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Affiliation(s)
- Yuying Liu
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, 173 Ashley Ave, Charleston, SC 29425, USA
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Talwar S, Balasubramanian S, Sundaramurthy S, House R, Wilusz CJ, Kuppuswamy D, D'Silva N, Gillespie MB, Hill EG, Palanisamy V. Overexpression of RNA-binding protein CELF1 prevents apoptosis and destabilizes pro-apoptotic mRNAs in oral cancer cells. RNA Biol 2013; 10:277-86. [PMID: 23324604 PMCID: PMC3594286 DOI: 10.4161/rna.23315] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
CELF1 RNA-binding protein, otherwise called CUGBP1, associates and coordinates the degradation of GU-rich element (GRE) containing mRNA’s encoding factors important for cell growth, migration and apoptosis. Although many substrates of CELF1 have been identified, the biological significance of CELF1-mediated mRNA decay remains unclear. As the processes modulated by CELF1 are frequently disrupted in cancer, we investigated the expression and role of CELF1 in oral squamous cancer cells (OSCCs). We determined that CELF1 is reproducibly overexpressed in OSCC tissues and cell lines. Moreover, depletion of CELF1 reduced proliferation and increased apoptosis in OSCCs, but had negligible effect in non-transformed cells. We found that CELF1 associates directly with the 3′UTR of mRNAs encoding the pro-apoptotic factors BAD, BAX and JunD and mediates their rapid decay. Specifically, 3′UTR fragment analysis of JunD revealed that the GRE region is critical for binding with CELF1 and expression of JunD in oral cancer cells. In addition, silencing of CELF1 rendered BAD, BAX and JunD mRNAs stable and increased their protein expression in oral cancer cells. Taken together, these results support a critical role for CELF1 in modulating apoptosis and implicate this RNA-binding protein as a cancer marker and potential therapeutic target.
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Affiliation(s)
- Sudha Talwar
- Department of Craniofacial Biology and Center for Oral Health Research, College of Dental Medicine, Medical University of South Carolina, Charleston, SC, USA
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Chu PC, Chuang HC, Kulp SK, Chen CS. The mRNA-stabilizing factor HuR protein is targeted by β-TrCP protein for degradation in response to glycolysis inhibition. J Biol Chem 2012; 287:43639-50. [PMID: 23115237 DOI: 10.1074/jbc.m112.393678] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The mRNA-stabilizing protein HuR acts a stress response protein whose function and/or protein stability are modulated by diverse stress stimuli through posttranslational modifications. Here, we report a novel mechanism by which metabolic stress facilitates proteasomal degradation of HuR in cancer cells. In response to the glucose transporter inhibitor CG-5, HuR translocates to the cytoplasm, where it is targeted by the ubiquitin E3 ligase β-TrCP1 for degradation. The cytoplasmic localization of HuR is facilitated by PKCα-mediated phosphorylation at Ser-318 as the Ser-318 → alanine substitution abolishes the ability of the resulting HuR to bind PKCα and to undergo nuclear export. The mechanistic link between β-TrCP1 and HuR degradation was supported by the ability of ectopically expressed β-TrCP1 to mimic CG-5 to promote HuR degradation and by the protective effect of dominant negative inhibition of β-TrCP1 on HuR ubiquitination and degradation. Substrate targeting of HuR by β-TrCP1 was further verified by coimmunoprecipitation and in vitro GST pull-down assays and by the identification of a β-TrCP1 recognition site. Although HuR does not contain a DSG destruction motif, we obtained evidence that β-TrCP1 recognizes an unconventional motif, (296)EEAMAIAS(304), in the RNA recognition motif 3. Furthermore, mutational analysis indicates that IKKα-dependent phosphorylation at Ser-304 is crucial to the binding of HuR to β-TrCP1. Mechanistically, this HuR degradation pathway differs from that reported for heat shock and hypoxia, which underlies the complexity in the regulation of HuR turnover under different stress stimuli. The ability of glycolysis inhibitors to target the expression of oncogenic proteins through HuR degradation might foster novel strategies for cancer therapy.
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Affiliation(s)
- Po-Chen Chu
- Division of Medicinal Chemistry, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43221, USA
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von Roretz C, Lian XJ, Macri AM, Punjani N, Clair E, Drouin O, Dormoy-Raclet V, Ma JF, Gallouzi IE. Apoptotic-induced cleavage shifts HuR from being a promoter of survival to an activator of caspase-mediated apoptosis. Cell Death Differ 2012; 20:154-68. [PMID: 22955946 DOI: 10.1038/cdd.2012.111] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Little is known about the cellular mechanisms modulating the shift in balance from a state of survival to cell death by caspase-mediated apoptosis in response to a lethal stress. Here we show that the RNA-binding protein HuR has an important function in mediating this switch. During caspase-mediated apoptosis, HuR is cleaved to generate two cleavage products (CPs). Our data demonstrate that the cleavage of HuR switches its function from being a prosurvival factor under normal conditions to becoming a promoter of apoptosis in response to a lethal stress. In the absence of an apoptotic stimuli, HuR associates with and promotes the expression of caspase-9 and prothymosin α (ProT) mRNAs, and pro- and antiapoptotic factors, respectively, both of which have been characterized as important players in determining cell fate. During the early steps of caspase-mediated apoptosis, however, the level of caspase-9 protein increases, while ProT remains unchanged. Under these conditions, the two HuR-CPs selectively bind to and stabilize caspase-9 mRNA, but do not bind to ProT. Hence, taken together, our data show that by maintaining a threshold of expression of proapoptotic factors such as caspase-9 in response to a lethal stress, the HuR-CPs help a cell to switch from resisting death to undergoing apoptosis.
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Affiliation(s)
- C von Roretz
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Center, McGill University, Montreal, Quebec, Canada
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