1
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Baños-Jaime B, Corrales-Guerrero L, Pérez-Mejías G, Rejano-Gordillo CM, Velázquez-Campoy A, Martínez-Cruz LA, Martínez-Chantar ML, De la Rosa MA, Díaz-Moreno I. Phosphorylation at the disordered N-end makes HuR accumulate and dimerize in the cytoplasm. Nucleic Acids Res 2024; 52:8552-8565. [PMID: 38966993 PMCID: PMC11317137 DOI: 10.1093/nar/gkae564] [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: 10/24/2023] [Revised: 05/30/2024] [Accepted: 07/02/2024] [Indexed: 07/06/2024] Open
Abstract
Human antigen R (HuR) is an RNA binding protein mainly involved in maintaining the stability and controlling the translation of mRNAs, critical for immune response, cell survival, proliferation and apoptosis. Although HuR is a nuclear protein, its mRNA translational-related function occurs at the cytoplasm, where the oligomeric form of HuR is more abundant. However, the regulation of nucleo-cytoplasmic transport of HuR and its connection with protein oligomerization remain unclear. In this work, we describe the phosphorylation of Tyr5 as a new hallmark for HuR activation. Our biophysical, structural and computational assays using phosphorylated and phosphomimetic HuR proteins demonstrate that phosphorylation of Tyr5 at the disordered N-end stretch induces global changes on HuR dynamics and conformation, modifying the solvent accessible surface of the HuR nucleo-cytoplasmic shuttling (HNS) sequence and releasing regions implicated in HuR dimerization. These findings explain the preferential cytoplasmic accumulation of phosphorylated HuR in HeLa cells, aiding to comprehend the mechanisms underlying HuR nucleus-cytoplasm shuttling and its later dimerization, both of which are relevant in HuR-related pathogenesis.
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Affiliation(s)
- Blanca Baños-Jaime
- Institute for Chemical Research (IIQ), Scientific Research Center "Isla de la Cartuja" (cicCartuja), University of Seville - CSIC, Seville 41092, Spain
| | - Laura Corrales-Guerrero
- Institute for Chemical Research (IIQ), Scientific Research Center "Isla de la Cartuja" (cicCartuja), University of Seville - CSIC, Seville 41092, Spain
| | - Gonzalo Pérez-Mejías
- Institute for Chemical Research (IIQ), Scientific Research Center "Isla de la Cartuja" (cicCartuja), University of Seville - CSIC, Seville 41092, Spain
| | - Claudia M Rejano-Gordillo
- Centre for Biomedical Research Network of Hepatic and Digestive Diseases (CIBERehd), Madrid 28029, Spain
- Liver Disease Lab, BRTA CIC bioGUNE, Derio 48160 Bizkaia, Spain
- Department of Biochemistry and Molecular Biology, Faculty of Sciences, University of Extremadura; University Institute of Biosanitary Research of Extremadura (INUBE), Badajoz 06071, Spain
| | - Adrián Velázquez-Campoy
- Institute for Biocomputation and Physic of Complex Systems (BIFI), Joint Unit GBsC-CSIC-BIFI, University of Zaragoza, Zaragoza 50018, Spain
- Departament of Biochemistry and Molecular and Cellular Biology, University of Zaragoza, Zaragoza 50009, Spain
- Institute for Health Research of Aragón (IIS Aragon), Zaragoza 50009, Spain
| | - Luis Alfonso Martínez-Cruz
- Centre for Biomedical Research Network of Hepatic and Digestive Diseases (CIBERehd), Madrid 28029, Spain
- Liver Disease Lab, BRTA CIC bioGUNE, Derio 48160 Bizkaia, Spain
| | - María Luz Martínez-Chantar
- Centre for Biomedical Research Network of Hepatic and Digestive Diseases (CIBERehd), Madrid 28029, Spain
- Liver Disease Lab, BRTA CIC bioGUNE, Derio 48160 Bizkaia, Spain
| | - Miguel A De la Rosa
- Institute for Chemical Research (IIQ), Scientific Research Center "Isla de la Cartuja" (cicCartuja), University of Seville - CSIC, Seville 41092, Spain
| | - Irene Díaz-Moreno
- Institute for Chemical Research (IIQ), Scientific Research Center "Isla de la Cartuja" (cicCartuja), University of Seville - CSIC, Seville 41092, Spain
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2
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Finan JM, Sutton TL, Dixon DA, Brody JR. Targeting the RNA-Binding Protein HuR in Cancer. Cancer Res 2023; 83:3507-3516. [PMID: 37683260 DOI: 10.1158/0008-5472.can-23-0972] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 07/12/2023] [Accepted: 09/06/2023] [Indexed: 09/10/2023]
Abstract
The RNA-binding protein human antigen R (HuR) is a well-established regulator of gene expression at the posttranscriptional level. Its dysregulation has been implicated in various human diseases, particularly cancer. In cancer, HuR is considered "active" when it shows increased subcellular localization in the cytoplasm, in addition to its normal nuclear localization. Cytoplasmic HuR plays a crucial role in stabilizing and enhancing the translation of prosurvival mRNAs that are involved in stress responses relevant to cancer progression, such as hypoxia, radiotherapy, and chemotherapy. In general, due to HuR's abundance and function in cancer cells compared with normal cells, it is an appealing target for oncology research. Exploiting the principles underlying HuR's role in tumorigenesis and resistance to stressors, targeting HuR has the potential for synergy with existing and novel oncologic therapies. This review aims to explore HuR's role in homeostasis and cancer pathophysiology, as well as current targeting strategies, which include silencing HuR expression, preventing its translocation and dimerization from the nucleus to the cytoplasm, and inhibiting mRNA binding. Furthermore, this review will discuss recent studies investigating the potential synergy between HuR inhibition and traditional chemotherapeutics.
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Affiliation(s)
- Jennifer M Finan
- Department of Surgery, Oregon Health & Science University, Portland, Oregon
| | - Thomas L Sutton
- Department of Surgery, Oregon Health & Science University, Portland, Oregon
| | - Dan A Dixon
- Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas
| | - Jonathan R Brody
- Department of Surgery, Oregon Health & Science University, Portland, Oregon
- Brenden-Colson Center for Pancreatic Care, Oregon Health & Science University, Portland, Oregon
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3
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Raheja H, George B, Tripathi SK, Saha S, Maiti TK, Das S. Hepatitis C virus non-structural proteins modulate cellular kinases for increased cytoplasmic abundance of host factor HuR and facilitate viral replication. PLoS Pathog 2023; 19:e1011552. [PMID: 37540723 PMCID: PMC10431626 DOI: 10.1371/journal.ppat.1011552] [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: 07/05/2023] [Revised: 08/16/2023] [Accepted: 07/11/2023] [Indexed: 08/06/2023] Open
Abstract
Host protein HuR translocation from nucleus to cytoplasm following infection is crucial for the life cycle of several RNA viruses including hepatitis C virus (HCV), a major causative agent of hepatocellular carcinoma. HuR assists the assembly of replication-complex on the viral-3'UTR, and its depletion hampers viral replication. Although cytoplasmic HuR is crucial for HCV replication, little is known about how the virus orchestrates the mobilization of HuR into the cytoplasm from the nucleus. We show that two viral proteins, NS3 and NS5A, act co-ordinately to alter the equilibrium of the nucleo-cytoplasmic movement of HuR. NS3 activates protein kinase C (PKC)-δ, which in-turn phosphorylates HuR on S318 residue, triggering its export to the cytoplasm. NS5A inactivates AMP-activated kinase (AMPK) resulting in diminished nuclear import of HuR through blockade of AMPK-mediated phosphorylation and acetylation of importin-α1. Cytoplasmic retention or entry of HuR can be reversed by an AMPK activator or a PKC-δ inhibitor. Our findings suggest that efforts should be made to develop inhibitors of PKC-δ and activators of AMPK, either separately or in combination, to inhibit HCV infection.
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Affiliation(s)
- Harsha Raheja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Biju George
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Sachin Kumar Tripathi
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | | | | | - Saumitra Das
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
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4
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Song C, Zhang Y, Li Y, Bie J, Wang Z, Yang X, Li H, Zhu L, Zhang T, Chang Q, Luo J. The phosphorylation of PHF5A by TrkA-ERK1/2-ABL1 cascade regulates centrosome separation. Cell Death Dis 2023; 14:98. [PMID: 36759599 PMCID: PMC9911754 DOI: 10.1038/s41419-023-05561-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/22/2022] [Accepted: 01/05/2023] [Indexed: 02/11/2023]
Abstract
During interphase, the newly duplicated pairs of centrosomes are held together by a centrosome linker, and the centrosome separation needs the disruption of this linker to induce the duplicated centrosomes separating into two distinct microtubule organization centers. The mechanism of regulating centrosome separation is however poorly understood. Here, we demonstrated that the phosphorylation of PHF5A at Y36 by the TrkA-ERK1/2-ABL1 cascade plays a critical role in regulating centrosome separation. PHF5A, a well-characterized spliceosome component, is enriched in the centrosome. The pY36-PHF5A promotes the interaction between CEP250 and Nek2A in a spliceosomal-independent manner, which leads to premature centrosome separation. Furthermore, the unmatured centrosome remodels the microtubule and subsequently regulates cell proliferation and migration. Importantly, we found that the phosphorylation cascade of TrkA-ERK1/2-ABL1-PHF5A is hyper-regulated in medulloblastoma. The inhibition of this cascade can induce senescence and restrict the proliferation of medulloblastoma. Our findings on this phosphorylation cascade in regulating centrosome separation could provide a series of potential targets for restricting the progress of medulloblastoma.
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Affiliation(s)
- Chen Song
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China
| | - Yu Zhang
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China
| | - Yutong Li
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China
| | - Juntao Bie
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China
| | - Zhe Wang
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China
- Institute for Cancer Genetics, Columbia University, New York, NY, 10032, USA
| | - Xin Yang
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China
- Institute for Cancer Genetics, Columbia University, New York, NY, 10032, USA
| | - Haishuang Li
- Department of Pathology, Peking University School of Basic Medical Science; Peking University Third Hospital, Peking University Health Science Center, Beijing, 100191, China
| | - Liangyi Zhu
- Department of Pathology, Peking University School of Basic Medical Science; Peking University Third Hospital, Peking University Health Science Center, Beijing, 100191, China
| | - Tianzhuo Zhang
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China
| | - Qing Chang
- Department of Pathology, Peking University School of Basic Medical Science; Peking University Third Hospital, Peking University Health Science Center, Beijing, 100191, China.
| | - Jianyuan Luo
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China.
- Department of Biochemistry and Biophysics, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Center for Medical Genetics, Peking University Health Science Center, Beijing, 100191, China.
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5
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Hu Antigen R (HuR) Protein Structure, Function and Regulation in Hepatobiliary Tumors. Cancers (Basel) 2022; 14:cancers14112666. [PMID: 35681645 PMCID: PMC9179498 DOI: 10.3390/cancers14112666] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/19/2022] [Accepted: 05/23/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary Hepatobiliary tumors are a group of primary malignancies encompassing the liver, the intra- and extra-hepatic biliary tracts, and the gall bladder. Within the liver, hepatocellular carcinoma (HCC) is the most common type of primary cancer, which is, also, representing the third-most recurrent cause of cancer-associated death and the sixth-most prevalent type of tumor worldwide, nowadays. Although less frequent, cholangiocarcinoma (CCA) is, currently, a fatal cancer with limited therapeutic options. Here, we review the regulatory role of Hu antigen R (HuR), a ubiquitous member of the ELAV/Hu family of RNA-binding proteins (RBPs), in the pathogenesis, progression, and treatment of HCC and CCA. Overall, HuR is proposed as a valuable diagnostic and prognostic marker, as well as a therapeutic target in hepatobiliary cancers. Therefore, novel therapeutic approaches that can selectively modulate HuR function appear to be highly attractive for the clinical management of these types of tumors. Abstract Hu antigen R (HuR) is a 36-kDa ubiquitous member of the ELAV/Hu family of RNA-binding proteins (RBPs), which plays an important role as a post-transcriptional regulator of specific RNAs under physiological and pathological conditions, including cancer. Herein, we review HuR protein structure, function, and its regulation, as well as its implications in the pathogenesis, progression, and treatment of hepatobiliary cancers. In particular, we focus on hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), tumors where the increased cytoplasmic localization of HuR and activity are proposed, as valuable diagnostic and prognostic markers. An overview of the main regulatory axes involving HuR, which are associated with cell proliferation, invasion, metastasis, apoptosis, and autophagy in HCC, is provided. These include the transcriptional, post-transcriptional, and post-translational modulators of HuR function, in addition to HuR target transcripts. Finally, whereas studies addressing the relevance of targeting HuR in CCA are limited, in the past few years, HuR has emerged as a potential therapeutic target in HCC. In fact, the therapeutic efficacy of some pharmacological inhibitors of HuR has been evaluated, in early experimental models of HCC. We, further, discuss the major findings and future perspectives of therapeutic approaches that specifically block HuR interactions, either with post-translational modifiers or cognate transcripts in hepatobiliary cancers.
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Assoni G, La Pietra V, Digilio R, Ciani C, Licata NV, Micaelli M, Facen E, Tomaszewska W, Cerofolini L, Pérez-Ràfols A, Varela Rey M, Fragai M, Woodhoo A, Marinelli L, Arosio D, Bonomo I, Provenzani A, Seneci P. HuR-targeted agents: An insight into medicinal chemistry, biophysical, computational studies and pharmacological effects on cancer models. Adv Drug Deliv Rev 2022; 181:114088. [PMID: 34942276 DOI: 10.1016/j.addr.2021.114088] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 10/07/2021] [Accepted: 12/16/2021] [Indexed: 12/13/2022]
Abstract
The Human antigen R (HuR) protein is an RNA-binding protein, ubiquitously expressed in human tissues, that orchestrates target RNA maturation and processing both in the nucleus and in the cytoplasm. A survey of known modulators of the RNA-HuR interactions is followed by a description of its structure and molecular mechanism of action - RRM domains, interactions with RNA, dimerization, binding modes with naturally occurring and synthetic HuR inhibitors. Then, the review focuses on HuR as a validated molecular target in oncology and briefly describes its role in inflammation. Namely, we show ample evidence for the involvement of HuR in the hallmarks and enabling characteristics of cancer, reporting findings from in vitro and in vivo studies; and we provide abundant experimental proofs of a beneficial role for the inhibition of HuR-mRNA interactions through silencing (CRISPR, siRNA) or pharmacological inhibition (small molecule HuR inhibitors).
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Affiliation(s)
- Giulia Assoni
- Chemistry Department, University of Milan, Via Golgi 19, I-20133 Milan, Italy; Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Valeria La Pietra
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy
| | - Rosangela Digilio
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Caterina Ciani
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Nausicaa Valentina Licata
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Mariachiara Micaelli
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Elisa Facen
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Weronika Tomaszewska
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Linda Cerofolini
- Magnetic Resonance Center (CERM), University of Florence and Interuniversity Consortium for Magnetic Resonance of Metalloproteins (CIRMMP), Via L. Sacconi 6, 50019 Sesto Fiorentino (FI), Italy
| | - Anna Pérez-Ràfols
- Giotto Biotech S.R.L., Via Madonna del Piano 6, 50019 Sesto Fiorentino (FI), Italy
| | - Marta Varela Rey
- Gene Regulatory Control in Disease Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute of Santiago de Compostela (IDIS), University of Santiago de Compostela, 15706 Santiago de Compostela, Spain
| | - Marco Fragai
- Magnetic Resonance Center (CERM), University of Florence and Interuniversity Consortium for Magnetic Resonance of Metalloproteins (CIRMMP), Via L. Sacconi 6, 50019 Sesto Fiorentino (FI), Italy
| | - Ashwin Woodhoo
- Gene Regulatory Control in Disease Group, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Health Research Institute of Santiago de Compostela (IDIS), University of Santiago de Compostela, 15706 Santiago de Compostela, Spain; Department of Functional Biology, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain; Galician Agency of Innovation (GAIN), Xunta de Galicia, Santiago de Compostela, Spain; Center for Cooperative Research in Biosciences (CIC bioGUNE, Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160 Derio, Spain; IKERBASQUE, Basque Foundation for Science, Bilbao 48013, Spain
| | - Luciana Marinelli
- Department of Pharmacy, University of Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy
| | - Daniela Arosio
- Istituto di Scienze e Tecnologie Chimiche "G. Natta" (SCITEC), National Research Council (CNR), Via C. Golgi 19, I-20133 Milan, Italy
| | - Isabelle Bonomo
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy
| | - Alessandro Provenzani
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy.
| | - Pierfausto Seneci
- Chemistry Department, University of Milan, Via Golgi 19, I-20133 Milan, Italy.
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7
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Zein-Sabatto H, Lerit DA. The Identification and Functional Analysis of mRNA Localizing to Centrosomes. Front Cell Dev Biol 2021; 9:782802. [PMID: 34805187 PMCID: PMC8595238 DOI: 10.3389/fcell.2021.782802] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 10/21/2021] [Indexed: 11/13/2022] Open
Abstract
Centrosomes are multifunctional organelles tasked with organizing the microtubule cytoskeleton required for genome stability, intracellular trafficking, and ciliogenesis. Contributing to the diversity of centrosome functions are cell cycle-dependent oscillations in protein localization and post-translational modifications. Less understood is the role of centrosome-localized messenger RNA (mRNA). Since its discovery, the concept of nucleic acids at the centrosome was controversial, and physiological roles for centrosomal mRNAs remained muddled and underexplored. Over the past decades, however, transcripts, RNA-binding proteins, and ribosomes were detected at the centrosome in various organisms and cell types, hinting at a conservation of function. Indeed, recent work defines centrosomes as sites of local protein synthesis, and defined mRNAs were recently implicated in regulating centrosome functions. In this review, we summarize the evidence for the presence of mRNA at the centrosome and the current work that aims to unravel the biological functions of mRNA localized to centrosomes.
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Affiliation(s)
| | - Dorothy A. Lerit
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, United States
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8
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Filippova N, Yang X, Ananthan S, Calano J, Pathak V, Bratton L, Vekariya RH, Zhang S, Ofori E, Hayward EN, Namkoong D, Crossman DK, Crowley MR, King PH, Mobley J, Nabors LB. Targeting the HuR Oncogenic Role with a New Class of Cytoplasmic Dimerization Inhibitors. Cancer Res 2021; 81:2220-2233. [PMID: 33602784 DOI: 10.1158/0008-5472.can-20-2858] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/29/2020] [Accepted: 02/10/2021] [Indexed: 11/16/2022]
Abstract
The development of novel therapeutics that exploit alterations in the activation state of key cellular signaling pathways due to mutations in upstream regulators has generated the field of personalized medicine. These first-generation efforts have focused on actionable mutations identified by deep sequencing of large numbers of tumor samples. We propose that a second-generation opportunity exists by exploiting key downstream "nodes of control" that contribute to oncogenesis and are inappropriately activated due to loss of upstream regulation and microenvironmental influences. The RNA-binding protein HuR represents such a node. Because HuR functionality in cancer cells is dependent on HuR dimerization and its nuclear/cytoplasmic shuttling, we developed a new class of molecules targeting HuR protein dimerization. A structure-activity relationship algorithm enabled development of inhibitors of HuR multimer formation that were soluble, had micromolar activity, and penetrated the blood-brain barrier. These inhibitors were evaluated for activity validation and specificity in a robust cell-based assay of HuR dimerization. SRI-42127, a molecule that met these criteria, inhibited HuR multimer formation across primary patient-derived glioblastoma xenolines (PDGx), leading to arrest of proliferation, induction of apoptosis, and inhibition of colony formation. SRI-42127 had favorable attributes with central nervous system penetration and inhibited tumor growth in mouse models. RNA and protein analysis of SRI-42127-treated PDGx xenolines across glioblastoma molecular subtypes confirmed attenuation of targets upregulated by HuR. These results highlight how focusing on key attributes of HuR that contribute to cancer progression, namely cytoplasmic localization and multimerization, has led to the development of a novel, highly effective inhibitor. SIGNIFICANCE: These findings utilize a cell-based mechanism of action assay with a structure-activity relationship compound development pathway to discover inhibitors that target HuR dimerization, a mechanism required for cancer promotion.
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Affiliation(s)
- Natalia Filippova
- Division of Neuro-oncology, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Xiuhua Yang
- Division of Neuro-oncology, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Subramaniam Ananthan
- Drug Discovery Division, Chemistry Department, Southern Research Institute, Birmingham, Alabama
| | - Jennifer Calano
- Division of Neuro-oncology, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Vibha Pathak
- Drug Discovery Division, Chemistry Department, Southern Research Institute, Birmingham, Alabama
| | - Larry Bratton
- Drug Discovery Division, Chemistry Department, Southern Research Institute, Birmingham, Alabama
| | - Rakesh H Vekariya
- Drug Discovery Division, Chemistry Department, Southern Research Institute, Birmingham, Alabama
| | - Sixue Zhang
- Drug Discovery Division, Chemistry Department, Southern Research Institute, Birmingham, Alabama
| | - Edward Ofori
- Drug Discovery Division, Chemistry Department, Southern Research Institute, Birmingham, Alabama
| | - Emily N Hayward
- Division of Neuro-oncology, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | - David Namkoong
- Division of Neuro-oncology, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama
| | - David K Crossman
- Department of Genetics, UAB Genomics Core, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michael R Crowley
- Department of Genetics, UAB Genomics Core, University of Alabama at Birmingham, Birmingham, Alabama
| | - Peter H King
- Department of Neurology, Birmingham Veterans Affairs Medical Center, Birmingham, Alabama
| | - James Mobley
- Division of Molecular and Translational Biomedicine, Department of Anesthesiology and Perioperative Medicine, O'Neal Comprehensive Cancer Center MS/Proteomics Shared Facility, University of Alabama at Birmingham, Birmingham, Alabama
| | - Louis B Nabors
- Division of Neuro-oncology, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama.
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9
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Filippova N, Nabors LB. ELAVL1 Role in Cell Fusion and Tunneling Membrane Nanotube Formations with Implication to Treat Glioma Heterogeneity. Cancers (Basel) 2020; 12:E3069. [PMID: 33096700 PMCID: PMC7590168 DOI: 10.3390/cancers12103069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/15/2020] [Accepted: 10/18/2020] [Indexed: 12/16/2022] Open
Abstract
Homotypic and heterotypic cell fusions via permanent membrane fusions and temporal tunneling nanotube formations in the glioma microenvironment were recently documented in vitro and in vivo and mediate glioma survival, plasticity, and recurrence. Chronic inflammation, a hypoxic environment, aberrant mitochondrial function, and ER stress due to unfolded protein accumulation upregulate cell fusion events, which leads to tumor heterogeneity and represents an adaptive mechanism to promote tumor cell survival and plasticity in cytotoxic, nutrient-deprived, mechanically stressed, and inflammatory microenvironments. Cell fusion is a multistep process, which consists of the activation of the cellular stress response, autophagy formation, rearrangement of cytoskeletal architecture in the areas of cell-to-cell contacts, and the expression of proinflammatory cytokines and fusogenic proteins. The mRNA-binding protein of ELAV-family HuR is a critical node, which orchestrates the stress response, autophagy formation, cytoskeletal architecture, and the expression of proinflammatory cytokines and fusogenic proteins. HuR is overexpressed in gliomas and is associated with poor prognosis and treatment resistance. Our review provides a link between the HuR role in the regulation of cell fusion and tunneling nanotube formations in the glioma microenvironment and the potential suppression of these processes by different classes of HuR inhibitors.
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Affiliation(s)
- Natalia Filippova
- Department of Neurology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Louis B. Nabors
- Department of Neurology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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10
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Ito KK, Watanabe K, Kitagawa D. The Emerging Role of ncRNAs and RNA-Binding Proteins in Mitotic Apparatus Formation. Noncoding RNA 2020; 6:E13. [PMID: 32245090 PMCID: PMC7151635 DOI: 10.3390/ncrna6010013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/09/2020] [Accepted: 03/13/2020] [Indexed: 12/14/2022] Open
Abstract
Mounting experimental evidence shows that non-coding RNAs (ncRNAs) serve a wide variety of biological functions. Recent studies suggest that a part of ncRNAs are critically important for supporting the structure of subcellular architectures. Here, we summarize the current literature demonstrating the role of ncRNAs and RNA-binding proteins in regulating the assembly of mitotic apparatus, especially focusing on centrosomes, kinetochores, and mitotic spindles.
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Affiliation(s)
| | | | - Daiju Kitagawa
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Science, The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan; (K.K.I.); (K.W.)
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Filippova N, Yang X, Ananthan S, Sorochinsky A, Hackney JR, Gentry Z, Bae S, King P, Nabors LB. Hu antigen R (HuR) multimerization contributes to glioma disease progression. J Biol Chem 2017; 292:16999-17010. [PMID: 28790173 DOI: 10.1074/jbc.m117.797878] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 07/27/2017] [Indexed: 12/21/2022] Open
Abstract
Among primary brain cancers, gliomas are the most deadly and most refractory to current treatment modalities. Previous reports overwhelmingly support the role of the RNA-binding protein Hu antigen R (HuR) as a positive regulator of glioma disease progression. HuR expression is consistently elevated in tumor tissues, and a cytoplasmic localization appears essential for HuR-dependent oncogenic transformation. Here, we report HuR aggregation (multimerization) in glioma and the analysis of this tumor-specific HuR protein multimerization in clinical brain tumor samples. Using a split luciferase assay, a bioluminescence resonance energy transfer technique, and site-directed mutagenesis, we examined the domains involved in HuR multimerization. Results obtained with the combination of the split HuR luciferase assay with the bioluminescence resonance energy transfer technique suggested that multiple (at least three) HuR molecules come together during HuR multimerization in glioma cells. Using these data, we developed a model of HuR multimerization in glioma cells. We also demonstrate that exposing glioma cells to the HuR inhibitor tanshinone group compound 15,16-dihydrotanshinone-I or to the newly identified compound 5 disrupts HuR multimerization modules and reduces tumor cell survival and proliferation. In summary, our findings provide new insights into HuR multimerization in glioma and highlight possible pharmacological approaches for targeting HuR domains involved in cancer cell-specific multimerization.
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Affiliation(s)
| | | | | | | | | | | | - Sejong Bae
- Medicine, School of Medicine, University of Alabama, Birmingham, Alabama 35294
| | - Peter King
- From the Departments of Neurology.,Birmingham Veterans Affairs Medical Center, Birmingham, Alabama 35294
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Vlasova-St Louis I, Bohjanen PR. Post-transcriptional regulation of cytokine and growth factor signaling in cancer. Cytokine Growth Factor Rev 2016; 33:83-93. [PMID: 27956133 DOI: 10.1016/j.cytogfr.2016.11.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 11/28/2016] [Indexed: 12/11/2022]
Abstract
Cytokines and growth factors regulate cell proliferation, differentiation, migration and apoptosis, and play important roles in coordinating growth signal responses during development. The expression of cytokine genes and the signals transmitted through cytokine receptors are tightly regulated at several levels, including transcriptional and post-transcriptional levels. A majority of cytokine mRNAs, including growth factor transcripts, contain AU-rich elements (AREs) in their 3' untranslated regions that control gene expression by regulating mRNA degradation and changing translational rates. In addition, numerous proteins involved in transmitting signals downstream of cytokine receptors are regulated at the level of mRNA degradation by GU-rich elements (GREs) found in their 3' untranslated regions. Abnormal stabilization and overexpression of ARE or GRE-containing transcripts had been observed in many malignancies, which is a consequence of the malfunction of RNA-binding proteins. In this review, we briefly summarize the role of AREs and GREs in regulating mRNA turnover to coordinate cytokine and growth factor expression, and we describe how dysregulation of mRNA degradation mechanisms contributes to the development and progression of cancer.
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Affiliation(s)
| | - Paul R Bohjanen
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN, USA
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Grammatikakis I, Abdelmohsen K, Gorospe M. Posttranslational control of HuR function. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27307117 DOI: 10.1002/wrna.1372] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 05/18/2016] [Accepted: 05/19/2016] [Indexed: 12/28/2022]
Abstract
The RNA-binding protein HuR (human antigen R) associates with numerous transcripts, coding and noncoding, and controls their splicing, localization, stability, and translation. Through its regulation of target transcripts, HuR has been implicated in cellular events including proliferation, senescence, differentiation, apoptosis, and the stress and immune responses. In turn, HuR influences processes such as cancer and inflammation. HuR function is primarily regulated through posttranslational modifications that alter its subcellular localization and its ability to bind target RNAs; such modifications include phosphorylation, methylation, ubiquitination, NEDDylation, and proteolytic cleavage. In this review, we describe the modifications that impact upon HuR function on gene expression programs and disease states. WIREs RNA 2017, 8:e1372. doi: 10.1002/wrna.1372 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Ioannis Grammatikakis
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Kotb Abdelmohsen
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - Myriam Gorospe
- Laboratory of Genetics, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
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Khabar KSA. Hallmarks of cancer and AU-rich elements. WILEY INTERDISCIPLINARY REVIEWS-RNA 2016; 8. [PMID: 27251431 PMCID: PMC5215528 DOI: 10.1002/wrna.1368] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/05/2016] [Accepted: 05/09/2016] [Indexed: 12/14/2022]
Abstract
Post‐transcriptional control of gene expression is aberrant in cancer cells. Sustained stabilization and enhanced translation of specific mRNAs are features of tumor cells. AU‐rich elements (AREs), cis‐acting mRNA decay determinants, play a major role in the posttranscriptional regulation of many genes involved in cancer processes. This review discusses the role of aberrant ARE‐mediated posttranscriptional processes in each of the hallmarks of cancer, including sustained cellular growth, resistance to apoptosis, angiogenesis, invasion, and metastasis. WIREs RNA 2017, 8:e1368. doi: 10.1002/wrna.1368 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Khalid S A Khabar
- King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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