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Evaluating a therapeutic window for precision medicine by integrating genomic profiles and p53 network dynamics. Commun Biol 2022; 5:924. [PMID: 36071176 PMCID: PMC9452682 DOI: 10.1038/s42003-022-03872-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 08/23/2022] [Indexed: 11/08/2022] Open
Abstract
The response variation to anti-cancer drugs originates from complex intracellular network dynamics of cancer. Such dynamic networks present challenges to determining optimal drug targets and stratifying cancer patients for precision medicine, although several cancer genome studies provided insights into the molecular characteristics of cancer. Here, we introduce a network dynamics-based approach based on attractor landscape analysis to evaluate the therapeutic window of a drug from cancer signaling networks combined with genomic profiles. This approach allows for effective screening of drug targets to explore potential target combinations for enhancing the therapeutic window of drug responses. We also effectively stratify patients into desired/undesired response groups using critical genomic determinants, which are network-specific origins of variability to drug response, and their dominance relationship. Our methods provide a viable and quantitative framework to connect genotype information to the phenotypes of drug response with regard to network dynamics determining the therapeutic window.
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2
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Wu T, Lei Y, Jin S, Zhao Q, Cheng W, Xi Y, Wang L, Wang Z, Niu X, Chen G. miRNA-467b inhibits Th17 differentiation by targeting eIF4E in experimental autoimmune encephalomyelitis. Mol Immunol 2021; 133:23-33. [PMID: 33621940 DOI: 10.1016/j.molimm.2021.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 11/23/2020] [Accepted: 02/08/2021] [Indexed: 12/30/2022]
Abstract
Multiple sclerosis (MS) and its animal model experimental autoimmune encephalomyelitis (EAE) are neuroinflammatory autoimmune diseases characterized by the axonal loss, demyelination, and neurodegeneration of the central nervous system. Overactivation of CD4+ T cells, especially the migration of the Th1 and Th17 subsets into the central nervous system (CNS), leads to the secretion of inflammatory mediators and destruction of the contact between neurons and activated macrophages, which can then result in a series of neurocognitive and motor deficits. In this study, we intended to explore the role of miRNA-467b in regulating Th cell development in EAE. We found that the level of miRNA-467b was decreased and eukaryotic initiation factor 4 F (eIF4E) was increased in lymph nodes and the CNS at EAE peak. eIF4E was confirmed as the direct target of miRNA467b. Overexpression of miRNA-467b could suppress a percentage of CD4+ IL-17+ cells in EAE CD4 + T cells in vitro. In addition, we also identified miRNA-467b, which could suppress Th17 cell differentiation by targeting eIF4E in vitro. Furthermore, injecting miRNA-467b mimics into the caudal vein of EAE mice contributed to less inflammation in the peripheral lymphoid organs and CNS and alleviated disease severity. Taken together, our findings imply that miRNA-467b inhibits the differentiation and function of Th17 cells by targeting eIF4E, thereby alleviating EAE.
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Affiliation(s)
- Ting Wu
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China; RenJi(North) Hospital Shanghai Jiaotong University School of Medicine, Shanghai 200135, China
| | - Yunxuan Lei
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China
| | - Shuxin Jin
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China
| | - Qing Zhao
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China; Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai JiaoTong University Affiliated Sixth People's Hospital, Shanghai 200233, China
| | - Wenjing Cheng
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China; The Fifth People's Hospital of YuHang District, Hangzhou 311100, China
| | - Yebin Xi
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China
| | - Li Wang
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China
| | - Zhaojun Wang
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China
| | - Xiaoyin Niu
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China.
| | - Guangjie Chen
- Department of Immunology and Microbiology, Shanghai JiaoTong University School of Medicine, Shanghai Institute of Immunology, Shanghai 200025, China.
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Jakopovic B, Horvatić A, Klobučar M, Gelemanović A, Grbčić P, Oršolić N, Jakopovich I, Kraljević Pavelić S. Treatment With Medicinal Mushroom Extract Mixture Inhibits Translation and Reprograms Metabolism in Advanced Colorectal Cancer Animal Model as Evidenced by Tandem Mass Tags Proteomics Analysis. Front Pharmacol 2020; 11:1202. [PMID: 32973493 PMCID: PMC7472604 DOI: 10.3389/fphar.2020.01202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/23/2020] [Indexed: 01/01/2023] Open
Abstract
Colorectal cancer (CRC) is the third most frequent cancer type in both males and females, with about 35% of patients being diagnosed in stage IV metastatic disease. Despite advancements in treatment, life expectancy in patients with metastatic disease is still not satisfying. Due to frequent drug resistance during conventional and targeted cancer treatments, the development and testing of multi-target therapies is an important research field. Medicinal mushrooms specific isolated compounds as well as complex extract mixtures have been studied in depth, and many mushroom species have been proven to be non-toxic multi-target inhibitors of specific oncogenic pathways, as well as potent immunomodulators. In this study, we have performed a tandem mass tags qualitative and quantitative proteomic analyses of CT26.WT colon cancer tumor tissues from Balb/c mice treated with the studied medicinal mushroom extract mixture, with or without 5-fluorouracil. Besides significantly improved survival, obtained results reveal that Agarikon.1 alone, and in combination with 5-fluorouracil exert their anticancer effects by affecting several fundamental processes important in CRC progression. Bioinformatic analysis of up- and downregulated proteins revealed that ribosomal biogenesis and translation is downregulated in treatment groups, while the unfolded protein response (UPR), lipid metabolism and tricarboxylic acid cycle (TCA) are upregulated. Moreover, we found that many known clinical biomarkers and protein clusters important in CRC progression and prognosis are affected, which are a good basis for an expanded translational study of the herein presented treatment.
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Affiliation(s)
| | - Anita Horvatić
- Proteomics Laboratory, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia
| | - Marko Klobučar
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | | | - Petra Grbčić
- Department of Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Nada Oršolić
- Division of Animal Physiology, Faculty of Science, University of Zagreb, Zagreb, Croatia
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Li N, Piao J, Wang X, Kim KY, Bae JY, Ren X, Lin Z. Paip1 Indicated Poor Prognosis in Cervical Cancer and Promoted Cervical Carcinogenesis. Cancer Res Treat 2019; 51:1653-1665. [PMID: 31010277 PMCID: PMC6790838 DOI: 10.4143/crt.2018.544] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 04/17/2019] [Indexed: 12/30/2022] Open
Abstract
Purpose This study was aimed to investigate the role of poly(A)-binding protein-interacting protein 1 (Paip1) in cervical carcinogenesis. Materials and Methods The expression of Paip1 in normal cervical epithelial tissues and cervical cancer (CC) tissues were detected by immunohistochemistry. In vivo and in vitro assays were performed to validate effect of Paip1 on CC progression. Results Paip1 was found to be up-regulated in CC, which was linked with shorter survival. Knockdown of Paip1 inhibited cell growth, induced apoptosis and cell cycle arrest in CC cells, whereas its overexpression reversed these effects. The in vivo tumor model confirmed the pro-tumor role of Paip1 in CC growth. Conclusion Altogether, the investigation demonstrated the clinical significance of Paip1 expression, which prompted that the up-regulated of Paip1 can presumably be a potential prognostic and progression marker for CC.
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Affiliation(s)
- Nan Li
- Department of Pathology & Cancer Research Center, Yanbian University Medical College, Yanji, China.,Key Laboratory of the Science and Technology, Department of Jilin Province, Yanji, China
| | - Junjie Piao
- Department of Pathology & Cancer Research Center, Yanbian University Medical College, Yanji, China.,Key Laboratory of the Science and Technology, Department of Jilin Province, Yanji, China
| | - Xinyue Wang
- Department of Pathology & Cancer Research Center, Yanbian University Medical College, Yanji, China.,Key Laboratory of the Science and Technology, Department of Jilin Province, Yanji, China
| | - Ki-Yeol Kim
- Brain Korea 21 Project, Yonsei University College of Dentistry, Seoul, Korea
| | - Jung Yoon Bae
- Department of Oral Pathology, Oral Cancer Research Institute, Yonsei University College of Dentistry, Seoul, Korea
| | - Xiangshan Ren
- Department of Pathology & Cancer Research Center, Yanbian University Medical College, Yanji, China.,Key Laboratory of the Science and Technology, Department of Jilin Province, Yanji, China
| | - Zhenhua Lin
- Department of Pathology & Cancer Research Center, Yanbian University Medical College, Yanji, China.,Key Laboratory of the Science and Technology, Department of Jilin Province, Yanji, China
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5
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Shirokikh NE, Preiss T. Translation initiation by cap-dependent ribosome recruitment: Recent insights and open questions. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1473. [PMID: 29624880 DOI: 10.1002/wrna.1473] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/02/2018] [Accepted: 02/14/2018] [Indexed: 12/14/2022]
Abstract
Gene expression universally relies on protein synthesis, where ribosomes recognize and decode the messenger RNA template by cycling through translation initiation, elongation, and termination phases. All aspects of translation have been studied for decades using the tools of biochemistry and molecular biology available at the time. Here, we focus on the mechanism of translation initiation in eukaryotes, which is remarkably more complex than prokaryotic initiation and is the target of multiple types of regulatory intervention. The "consensus" model, featuring cap-dependent ribosome entry and scanning of mRNA leader sequences, represents the predominantly utilized initiation pathway across eukaryotes, although several variations of the model and alternative initiation mechanisms are also known. Recent advances in structural biology techniques have enabled remarkable molecular-level insights into the functional states of eukaryotic ribosomes, including a range of ribosomal complexes with different combinations of translation initiation factors that are thought to represent bona fide intermediates of the initiation process. Similarly, high-throughput sequencing-based ribosome profiling or "footprinting" approaches have allowed much progress in understanding the elongation phase of translation, and variants of them are beginning to reveal the remaining mysteries of initiation, as well as aspects of translation termination and ribosomal recycling. A current view on the eukaryotic initiation mechanism is presented here with an emphasis on how recent structural and footprinting results underpin axioms of the consensus model. Along the way, we further outline some contested mechanistic issues and major open questions still to be addressed. This article is categorized under: Translation > Translation Mechanisms Translation > Translation Regulation RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Nikolay E Shirokikh
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
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6
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MacNicol MC, Cragle CE, McDaniel FK, Hardy LL, Wang Y, Arumugam K, Rahmatallah Y, Glazko GV, Wilczynska A, Childs GV, Zhou D, MacNicol AM. Evasion of regulatory phosphorylation by an alternatively spliced isoform of Musashi2. Sci Rep 2017; 7:11503. [PMID: 28912529 PMCID: PMC5599597 DOI: 10.1038/s41598-017-11917-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/01/2017] [Indexed: 01/06/2023] Open
Abstract
The Musashi family of RNA binding proteins act to promote stem cell self-renewal and oppose cell differentiation predominantly through translational repression of mRNAs encoding pro-differentiation factors and inhibitors of cell cycle progression. During tissue development and repair however, Musashi repressor function must be dynamically regulated to allow cell cycle exit and differentiation. The mechanism by which Musashi repressor function is attenuated has not been fully established. Our prior work indicated that the Musashi1 isoform undergoes site-specific regulatory phosphorylation. Here, we demonstrate that the canonical Musashi2 isoform is subject to similar regulated site-specific phosphorylation, converting Musashi2 from a repressor to an activator of target mRNA translation. We have also characterized a novel alternatively spliced, truncated isoform of human Musashi2 (variant 2) that lacks the sites of regulatory phosphorylation and fails to promote translation of target mRNAs. Consistent with a role in opposing cell cycle exit and differentiation, upregulation of Musashi2 variant 2 was observed in a number of cancers and overexpression of the Musashi2 variant 2 isoform promoted cell transformation. These findings indicate that alternately spliced isoforms of the Musashi protein family possess distinct functional and regulatory properties and suggest that differential expression of Musashi isoforms may influence cell fate decisions.
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Affiliation(s)
- Melanie C MacNicol
- University of Arkansas for Medical Sciences, Department of Neurobiology and Developmental Sciences, 4301 W. Markham, Little Rock, 72205, AR, USA.,University of Arkansas for Medical Science, Center for Translational Neuroscience, 4301 W. Markham, Little Rock, 72205, AR, USA
| | - Chad E Cragle
- University of Arkansas for Medical Sciences, Department of Neurobiology and Developmental Sciences, 4301 W. Markham, Little Rock, 72205, AR, USA
| | - F Kennedy McDaniel
- University of Arkansas for Medical Sciences, Department of Neurobiology and Developmental Sciences, 4301 W. Markham, Little Rock, 72205, AR, USA
| | - Linda L Hardy
- University of Arkansas for Medical Sciences, Department of Neurobiology and Developmental Sciences, 4301 W. Markham, Little Rock, 72205, AR, USA
| | - Yan Wang
- University of Arkansas for Medical Sciences, Department of Pharmaceutical Sciences, 4301 W. Markham, Little Rock, 72205, AR, USA.,Department of Orthopedics, Guangzhou First People's Hospital, Guangzhou Medical University, Guangzhou, Guangdong, 510182, PR China
| | - Karthik Arumugam
- University of Arkansas for Medical Sciences, Department of Physiology and Biophysics, 4301 W. Markham, Little Rock, 72205, AR, USA.,Center for Genomic Regulation, Department of Gene Regulation, Stem Cells and Cancer, C/Dr. Aiguader 88, 08003, Barcelona, Spain
| | - Yasir Rahmatallah
- University of Arkansas for Medical Sciences, Department of Biomedical Informatics, 4301 W. Markham, Little Rock, 72205, AR, USA
| | - Galina V Glazko
- University of Arkansas for Medical Sciences, Department of Biomedical Informatics, 4301 W. Markham, Little Rock, 72205, AR, USA
| | | | - Gwen V Childs
- University of Arkansas for Medical Sciences, Department of Neurobiology and Developmental Sciences, 4301 W. Markham, Little Rock, 72205, AR, USA.,University of Arkansas for Medical Science, Center for Translational Neuroscience, 4301 W. Markham, Little Rock, 72205, AR, USA
| | - Daohong Zhou
- University of Arkansas for Medical Sciences, Department of Pharmaceutical Sciences, 4301 W. Markham, Little Rock, 72205, AR, USA
| | - Angus M MacNicol
- University of Arkansas for Medical Sciences, Department of Neurobiology and Developmental Sciences, 4301 W. Markham, Little Rock, 72205, AR, USA. .,Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR, 72205, United States.
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7
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Kwegyir-Afful AK, Murigi FN, Purushottamachar P, Ramamurthy VP, Martin MS, Njar VCO. Galeterone and its analogs inhibit Mnk-eIF4E axis, synergize with gemcitabine, impede pancreatic cancer cell migration, invasion and proliferation and inhibit tumor growth in mice. Oncotarget 2016; 8:52381-52402. [PMID: 28881737 PMCID: PMC5581036 DOI: 10.18632/oncotarget.14154] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 11/19/2016] [Indexed: 12/22/2022] Open
Abstract
Survival rate for pancreatic cancer (pancreatic ductal adenocarcinoma, PDAC) is poor, with about 80% of patients presenting with the metastatic disease. Gemcitabine, the standard chemotherapeutic agent for locally advanced and metastatic PDAC has limited efficacy, attributed to innate/acquired resistance and activation of pro-survival pathways. The Mnk1/2-eIF4E and NF-κB signaling pathways are implicated in PDAC disease progression/metastasis and also associated with gemcitabine-induced resistance in PDAC. Galeterone (gal), a multi-target, agent in phase III clinical development for prostate cancer has also shown effects on the aforementioned pathways. We show for the first time, that gal/analogs (VNPT55, VNPP414 and VNPP433-3β) profoundly inhibited cell viability of gemcitabine-naive/resistance PDAC cell lines and strongly synergized with gemcitabine in gemcitabine-resistant PDAC cells. In addition, to inducing G1 cell cycle arrest, gal/analogs induced caspase 3-mediated cell-death of PDAC cells. Gal/analogs caused profound downregulation of Mnk1/2, peIF4E and NF-κB (p-p65), metastatic inducing factors (N-cadherin, MMP-1/-2/-9, Slug, Snail and CXCR4) and putative stem cell factors, (β-Catenin, Nanog, BMI-1 and Oct-4). Gal/analog also depleted EZH2 and upregulated E-Cadherin. These effects resulted in significant inhibition of PDAC cell migration, invasion and proliferation. Importantly, we also observed strong MiaPaca-2 tumor xenograft growth inhibition (61% to 92%). Collectively, these promising findings strongly support further development of gal/analogs as novel therapeutics for PDAC.
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Affiliation(s)
- Andrew K Kwegyir-Afful
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA.,Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA
| | - Francis N Murigi
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA.,Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA
| | - Puranik Purushottamachar
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA.,Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA
| | - Vidya P Ramamurthy
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA.,Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA
| | - Marlena S Martin
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA.,Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA.,Current Address: Bernard J. Dunn School of Pharmacy, Shenandoah University, Ashburn, VA 20147, USA
| | - Vincent C O Njar
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA.,Center for Biomolecular Therapeutics, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA.,Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201-1559, USA
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8
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Cell type-specific control of protein synthesis and proliferation by FGF-dependent signaling to the translation repressor 4E-BP. Proc Natl Acad Sci U S A 2016; 113:7545-50. [PMID: 27313212 DOI: 10.1073/pnas.1605451113] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Regulation of protein synthesis plays a vital role in posttranscriptional modulation of gene expression. Translational control most commonly targets the initiation of protein synthesis: loading 40S ribosome complexes onto mRNA and AUG start codon recognition. This step is initiated by eukaryotic initiation factor 4E (eIF4E) (the m7GTP cap-binding protein), whose binding to eIF4G (a scaffolding subunit) and eIF4A (an ATP-dependent RNA helicase) leads to assembly of active eIF4F complex. The ability of eIF4E to recognize the cap is prevented by its binding to eIF4E binding protein (4E-BP), which thereby inhibits cap-dependent translation by sequestering eIF4E. The 4E-BP activity is, in turn, inhibited by mTORC1 [mTOR (the mechanistic target of rapamycin) complex 1] mediated phosphorylation. Here, we define a previously unidentified mechanism of mTOR-independent 4E-BP1 regulation that is used by chondrocytes upon FGF signaling. Chondrocytes are responsible for the formation of the skeleton long bones. Unlike the majority of cell types where FGF signaling triggers proliferation, chondrocytes respond to FGF with inhibition. We establish that FGF specifically suppresses protein synthesis in chondrocytes, but not in any other cells of mesenchymal origin. Furthermore, 4E-BP1 repressor activity is necessary not only for suppression of protein synthesis, but also for FGF-induced cell-cycle arrest. Importantly, FGF-induced changes in the 4E-BP1 activity observed in cell culture are likewise detected in vivo and reflect the action of FGF signaling on downstream targets during bone development. Thus, our findings demonstrate that FGF signaling differentially impacts protein synthesis through either stimulation or repression, in a cell-type-dependent manner, with 4E-BP1 being a key player.
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9
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ur Rasool R, Rah B, Amin H, Nayak D, Chakraborty S, Rawoof A, Mintoo MJ, Yousuf K, Mukherjee D, Kumar LD, Mondhe DM, Goswami A. Dual modulation of Ras-Mnk and PI3K-AKT-mTOR pathways: A Novel c-FLIP inhibitory mechanism of 3-AWA mediated translational attenuation through dephosphorylation of eIF4E. Sci Rep 2016; 6:18800. [PMID: 26728896 PMCID: PMC4700468 DOI: 10.1038/srep18800] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/24/2015] [Indexed: 12/19/2022] Open
Abstract
The eukaryotic translation initiation factor 4E (eIF4E) is considered as a key survival protein involved in cell cycle progression, transformation and apoptosis resistance. Herein, we demonstrate that medicinal plant derivative 3-AWA (from Withaferin A) suppressed the proliferation and metastasis of CaP cells through abrogation of eIF4E activation and expression via c-FLIP dependent mechanism. This translational attenuation prevents the de novo synthesis of major players of metastatic cascades viz. c-FLIP, c-Myc and cyclin D1. Moreover, the suppression of c-FLIP due to inhibition of translation initiation complex by 3-AWA enhanced FAS trafficking, BID and caspase 8 cleavage. Further ectopically restored c-Myc and GFP-HRas mediated activation of eIF4E was reduced by 3-AWA in transformed NIH3T3 cells. Detailed underlying mechanisms revealed that 3-AWA inhibited Ras-Mnk and PI3-AKT-mTOR, two major pathways through which eIF4E converges upon eIF4F hub. In addition to in vitro studies, we confirmed that 3-AWA efficiently suppressed tumor growth and metastasis in different mouse models. Given that 3-AWA inhibits c-FLIP through abrogation of translation initiation by co-targeting mTOR and Mnk-eIF4E, it (3-AWA) can be exploited as a lead pharmacophore for promising anti-cancer therapeutic development.
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Affiliation(s)
- Reyaz ur Rasool
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
- Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Bilal Rah
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
- Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Hina Amin
- Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Debasis Nayak
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
- Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Souneek Chakraborty
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
- Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Abdul Rawoof
- Center for Cellular and Molecular Biology, Uppal Road, Hyderabad, AP-50007, India
| | - Mubashir Javed Mintoo
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
- Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Khalid Yousuf
- Natural Product Chemistry, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Debaraj Mukherjee
- Natural Product Chemistry, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Lekha Dinesh Kumar
- Center for Cellular and Molecular Biology, Uppal Road, Hyderabad, AP-50007, India
| | - Dilip Manikaro Mondhe
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
- Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
| | - Anindya Goswami
- Academy of Scientific & Innovative Research (AcSIR), New Delhi, India
- Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR), Canal Road, Jammu Tawi, J&K – 180001, India
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10
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Attar-Schneider O, Zismanov V, Dabbah M, Tartakover-Matalon S, Drucker L, Lishner M. Multiple myeloma and bone marrow mesenchymal stem cells' crosstalk: Effect on translation initiation. Mol Carcinog 2015; 55:1343-54. [PMID: 26293751 DOI: 10.1002/mc.22378] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 07/15/2015] [Accepted: 07/23/2015] [Indexed: 12/26/2022]
Abstract
Multiple myeloma (MM) malignant plasma cells reside in the bone marrow (BM) and convert it into a specialized pre-neoplastic niche that promotes the proliferation and survival of the cancer cells. BM resident mesenchymal stem cells (BM-MSCs) are altered in MM and in vitro studies indicate their transformation by MM proximity is within hours. The response time frame suggested that protein translation may be implicated. Thus, we assembled a co-culture model of MM cell lines with MSCs from normal donors (ND) and MM patients to test our hypothesis. The cell lines (U266, ARP-1) and BM-MSCs (ND, MM) were harvested separately after 72 h of co-culture and assayed for proliferation, death, levels of major translation initiation factors (eIF4E, eIF4GI), their targets, and regulators. Significant changes were observed: BM-MSCs (ND and MM) co-cultured with MM cell lines displayed elevated proliferation and death as well as increased expression/activity of eIF4E/eIF4GI; MM cell lines co-cultured with MM-MSCs also displayed higher proliferation and death rates coupled with augmented translation initiation factors; in contrast, MM cell lines co-cultured with ND-MSCs did not display elevated proliferation only death and had no changes in eIF4GI levels/activity. eIF4E expression was increased in one of the cell lines. Our study demonstrates that there is direct dialogue between the MM and BM-MSCs populations that includes translation initiation manipulation and critically affects cell fate. Future research should be aimed at identifying therapeutic targets that may be used to minimize the collateral damage to the cancer microenvironment and limit its recruitment into the malignant process. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Oshrat Attar-Schneider
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Victoria Zismanov
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mahmoud Dabbah
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shelly Tartakover-Matalon
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Liat Drucker
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michael Lishner
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Internal Medicine, Meir Medical Center, Kfar Saba, Israel
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MacNicol AM, Hardy LL, Spencer HJ, MacNicol MC. Neural stem and progenitor cell fate transition requires regulation of Musashi1 function. BMC DEVELOPMENTAL BIOLOGY 2015; 15:15. [PMID: 25888190 PMCID: PMC4369890 DOI: 10.1186/s12861-015-0064-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 02/26/2015] [Indexed: 12/28/2022]
Abstract
Background There is increasing evidence of a pivotal role for regulated mRNA translation in control of developmental cell fate transitions. Physiological and pathological stem and progenitor cell self-renewal is maintained by the mRNA-binding protein, Musashi1 through repression of translation of key mRNAs encoding cell cycle inhibitory proteins. The mechanism by which Musashi1 function is modified to allow translation of these target mRNAs under conditions that require inhibition of cell cycle progression, is unknown. Results In this study, we demonstrate that differentiation of primary embryonic rat neural stem/progenitor cells (NSPCs) or human neuroblastoma SH-SY5Y cells results in the rapid phosphorylation of Musashi1 on the evolutionarily conserved site serine 337 (S337). Phosphorylation of this site has been shown to be required for cell cycle control during the maturation of Xenopus oocytes. S337 phosphorylation in mammalian NSPCs and human SH-SY5Y cells correlates with the de-repression and translation of a Musashi reporter mRNA and with accumulation of protein from the endogenous Musashi target mRNA, p21WAF1/CIP1. Inhibition of Musashi regulatory phosphorylation, through expression of a phospho-inhibitory mutant Musashi1 S337A or over-expression of the wild-type Musashi, blocked differentiation of both NSPCs and SH-SY5Y cells. Musashi1 was similarly phosphorylated in NSPCs and SH-SY5Y cells under conditions of nutrient deprivation-induced cell cycle arrest. Expression of the Musashi1 S337A mutant protein attenuated nutrient deprivation-induced NSPC and SH-SY5Y cell death. Conclusions Our data suggest that in response to environmental cues that oppose cell cycle progression, regulation of Musashi function is required to promote target mRNA translation and cell fate transition. Forced modulation of Musashi1 function may present a novel therapeutic strategy to oppose pathological stem cell self-renewal.
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Affiliation(s)
- Angus M MacNicol
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, 4301 W. Markham, Slot 814, Little Rock, AR, 72205, USA. .,Winthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR, 72205, USA.
| | - Linda L Hardy
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, 4301 W. Markham, Slot 814, Little Rock, AR, 72205, USA.
| | - Horace J Spencer
- Department of Biostatistics, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR, 72205, USA.
| | - Melanie C MacNicol
- Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, 4301 W. Markham, Slot 814, Little Rock, AR, 72205, USA. .,Center for Translational Neuroscience, University of Arkansas for Medical Sciences, 4301 W. Markham, Little Rock, AR, 72205, USA.
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12
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Mbatia HW, Ramalingam S, Ramamurthy VP, Martin MS, Kwegyir-Afful AK, Njar VCO. Novel C-4 heteroaryl 13-cis-retinamide Mnk/AR degrading agents inhibit cell proliferation and migration and induce apoptosis in human breast and prostate cancer cells and suppress growth of MDA-MB-231 human breast and CWR22Rv1 human prostate tumor xenografts in mice. J Med Chem 2015; 58:1900-14. [PMID: 25634130 DOI: 10.1021/jm501792c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The synthesis and in vitro and in vivo antibreast and antiprostate cancers activities of novel C-4 heteroaryl 13-cis-retinamides that modulate Mnk-eIF4E and AR signaling are discussed. Modifications of the C-4 heteroaryl substituents reveal that the 1H-imidazole is essential for high anticancer activity. The most potent compounds against a variety of human breast and prostate cancer (BC/PC) cell lines were compounds 16 (VNHM-1-66), 20 (VNHM-1-81), and 22 (VNHM-1-73). In these cell lines, the compounds induce Mnk1/2 degradation to substantially suppress eIF4E phosphorylation. In PC cells, the compounds induce degradation of both full-length androgen receptor (fAR) and splice variant AR (AR-V7) to inhibit AR transcriptional activity. More importantly, VNHM-1-81 has strong in vivo antibreast and antiprostate cancer activities, while VNHM-1-73 exhibited strong in vivo antibreast cancer activity, with no apparent host toxicity. Clearly, these lead compounds are strong candidates for development for the treatments of human breast and prostate cancers.
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Affiliation(s)
- Hannah W Mbatia
- Department of Pharmacology, ‡Center for Biomolecular Therapeutics, and §Marlene Stewart Greenebaum Cancer Center, University of Maryland School of Medicine , 685 West Baltimore Street, Baltimore, Maryland 21201-1559, United States
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13
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Avdulov S, Herrera J, Smith K, Peterson M, Gomez-Garcia JR, Beadnell TC, Schwertfeger KL, Benyumov AO, Manivel JC, Li S, Bielinsky AK, Yee D, Bitterman PB, Polunovsky VA. eIF4E threshold levels differ in governing normal and neoplastic expansion of mammary stem and luminal progenitor cells. Cancer Res 2014; 75:687-97. [PMID: 25524901 DOI: 10.1158/0008-5472.can-14-2571] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Translation initiation factor eIF4E mediates normal cell proliferation, yet induces tumorigenesis when overexpressed. The mechanisms by which eIF4E directs such distinct biologic outputs remain unknown. We found that mouse mammary morphogenesis during pregnancy and lactation is accompanied by increased cap-binding capability of eIF4E and activation of the eIF4E-dependent translational apparatus, but only subtle oscillations in eIF4E abundance. Using a transgenic mouse model engineered so that lactogenic hormones stimulate a sustained increase in eIF4E abundance in stem/progenitor cells of lactogenic mammary epithelium during successive pregnancy/lactation cycles, eIF4E overexpression increased self-renewal, triggered DNA replication stress, and induced formation of premalignant and malignant lesions. Using complementary in vivo and ex vivo approaches, we found that increasing eIF4E levels rescued cells harboring oncogenic c-Myc or H-RasV12 from DNA replication stress and oncogene-induced replication catastrophe. Our findings indicate that distinct threshold levels of eIF4E govern its biologic output in lactating mammary glands and that eIF4E overexpression in the context of stem/progenitor cell population expansion can initiate malignant transformation by enabling cells to evade DNA damage checkpoints activated by oncogenic stimuli. Maintaining eIF4E levels below its proneoplastic threshold is an important anticancer defense in normal cells, with important implications for understanding pregnancy-associated breast cancer.
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Affiliation(s)
- Svetlana Avdulov
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Jeremy Herrera
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Karen Smith
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Mark Peterson
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | | | - Thomas C Beadnell
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota
| | - Kathryn L Schwertfeger
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota. Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Alexey O Benyumov
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - J Carlos Manivel
- Department of Laboratory Medicine and Pathology, University of Minnesota, Minneapolis, Minnesota
| | - Shunan Li
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota
| | - Anja-Katrin Bielinsky
- Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota. Departament of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota
| | - Douglas Yee
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota. Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota
| | - Peter B Bitterman
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota. Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota.
| | - Vitaly A Polunovsky
- Department of Medicine, University of Minnesota, Minneapolis, Minnesota. Masonic Cancer Center, University of Minnesota, Minneapolis, Minnesota.
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14
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Bitterman PB, Polunovsky VA. eIF4E-mediated translational control of cancer incidence. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:774-80. [PMID: 25263391 DOI: 10.1016/j.bbagrm.2014.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 09/03/2014] [Accepted: 09/10/2014] [Indexed: 11/16/2022]
Abstract
Mitogen activated translation initiation factor eIF4E mediates normal cell proliferation, yet induces tumorigenesis when deregulated and overexpressed. It remains unknown, how activated eIF4E directs such distinct biological outputs. Our experimental data provide evidence that distinct threshold levels of eIF4E govern its biological output in lactating mammary glands and that eIF4E overexpression in the context of cell population expansion can initiate malignant transformation by enabling cells to evade DNA damage checkpoints caused by hyperproliferative oncogenic stimuli. These findings point at the cellular level of eIF4E as an important sensor for normal or pro-neoplastic propagation of cells. Here, we describe a model that links the pro-neoplastic function of eIF4F to its ability to disable oncogene-activated tumor surveillance programs; and propose a novel therapeutic strategy for cancer prevention based upon targeting aberrant eIF4E with safe doses of small-molecule antagonists to ensure the maintenance of eIF4E levels below the pro-neoplastic threshold. This article is part of a Special Issue entitled: Translation and Cancer.
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Affiliation(s)
- Peter B Bitterman
- Department of Medicine, University of Minnesota, 420 Delaware Street S.E., MMC 276, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota, 420 Delaware Street S.E., MMC 276, Minneapolis, MN 55455, USA.
| | - Vitaly A Polunovsky
- Department of Medicine, University of Minnesota, 420 Delaware Street S.E., MMC 276, Minneapolis, MN 55455, USA; Masonic Cancer Center, University of Minnesota, 420 Delaware Street S.E., MMC 276, Minneapolis, MN 55455, USA.
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15
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Small-molecule inhibition of oncogenic eukaryotic protein translation in mesothelioma cells. Invest New Drugs 2014; 32:598-603. [DOI: 10.1007/s10637-014-0076-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 02/18/2014] [Indexed: 02/01/2023]
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Resistance to EGFR-TKI can be mediated through multiple signaling pathways converging upon cap-dependent translation in EGFR-wild type NSCLC. J Thorac Oncol 2014; 8:1142-7. [PMID: 23883783 DOI: 10.1097/jto.0b013e31829ce963] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
INTRODUCTION For the majority of patients with non-small-cell lung cancer (NSCLC), response to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is suboptimal. In models of acquired resistance to EGFR-TKI, activation of Akt phosphorylation is frequently observed. Because Akt activation results in downstream initiation of cap-dependent protein translation, we hypothesized that a strategy of targeting cap-dependent translation in combination with erlotinib might enhance therapy. METHODS NSCLC cells that are wild type for EGFR were assayed for sensitivity to erlotinib. Serum-starved NSCLC cells were assayed for EGFR signaling and downstream pathway activation by immunoblot after stimulation with epidermal growth factor. EGFR signaling and signaling mediators of cap-dependent translation were assayed by immunoblot under serum-replete conditions 24 hours after treatment with erlotinib. Finally, combination treatment with erlotinib and two different cap-dependent translation inhibitors were done to assess the effect on cell viability. RESULTS EGFR signaling is coupled to activation of cap-dependent translation in EGFR wild-type cells. Erlotinib inhibits EGFR phosphorylation in EGFR-TKI resistant cells, however, results in activation of downstream signaling molecules including Akt and extracellular regulated kinase, ERK 1/2, resulting in maintenance of eukaryotic initiation factor 4F (eIF4F) activation. eIF4F cap-complex formation is maintained in erlotinib-resistant cells, but not in erlotinib-sensitive cells. Finally, using an antisense oligonucleotide against eukaryotic translation initiation factor 4E and a small-molecule inhibitor to disrupt eIF4F formation, we show that cap-dependent translation inhibition can enhance sensitivity to erlotinib. CONCLUSION The results of these studies support further clinical development of translation inhibitors for treatment of NSCLC in combination with erlotinib.
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Behar M, Barken D, Werner SL, Hoffmann A. The dynamics of signaling as a pharmacological target. Cell 2013; 155:448-61. [PMID: 24120141 DOI: 10.1016/j.cell.2013.09.018] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 06/17/2013] [Accepted: 09/09/2013] [Indexed: 02/06/2023]
Abstract
Highly networked signaling hubs are often associated with disease, but targeting them pharmacologically has largely been unsuccessful in the clinic because of their functional pleiotropy. Motivated by the hypothesis that a dynamic signaling code confers functional specificity, we investigated whether dynamic features may be targeted pharmacologically to achieve therapeutic specificity. With a virtual screen, we identified combinations of signaling hub topologies and dynamic signal profiles that are amenable to selective inhibition. Mathematical analysis revealed principles that may guide stimulus-specific inhibition of signaling hubs, even in the absence of detailed mathematical models. Using the NFκB signaling module as a test bed, we identified perturbations that selectively affect the response to cytokines or pathogen components. Together, our results demonstrate that the dynamics of signaling may serve as a pharmacological target, and we reveal principles that delineate the opportunities and constraints of developing stimulus-specific therapeutic agents aimed at pleiotropic signaling hubs.
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Affiliation(s)
- Marcelo Behar
- Signaling Systems Laboratory, Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA; San Diego Center for Systems Biology, University of California, San Diego, La Jolla, CA 92093, USA; Computational Biosciences Institute, University of California, Los Angeles, Los Angeles, CA 90025, USA; Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90025, USA
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Oncogenic activation of MEK/ERK primes melanoma cells for adaptation to endoplasmic reticulum stress. J Invest Dermatol 2013; 134:488-497. [PMID: 23921951 DOI: 10.1038/jid.2013.325] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Revised: 06/21/2013] [Accepted: 07/07/2013] [Indexed: 02/07/2023]
Abstract
Cancer cells commonly undergo chronic endoplasmic reticulum (ER) stress, to which the cells have to adapt for survival and proliferation. We report here that in melanoma cells intrinsic activation of the ER stress response/unfolded protein response (UPR) is, at least in part, caused by increased outputs of protein synthesis driven by oncogenic activation of mitogen-activated protein kinase kinase/extracellular signal-regulated kinase (MEK/ERK) and promotes proliferation and protects against apoptosis induced by acute ER stress. Inhibition of oncogenic BRAF(V600E) or MEK-attenuated activation of inositol-requiring enzyme 1 (IRE1) and activating transcription factor 6 (ATF6) signaling of the UPR in melanoma cells. This was associated with decreased phosphorylation of eukaryotic initiation factor 4E (eIF4E) and nascent protein synthesis and was recapitulated by knockdown of eIF4E. In line with this, introduction of BRAF(V600E) into melanocytes led to increases in eIF4E phosphorylation and protein production and triggered activation of the UPR. Similar to knockdown of glucose-regulated protein 78 (GRP78), inhibition of XBP1 decelerated melanoma cell proliferation and enhanced apoptosis induced by the pharmacological ER stress inducers tunicamycin and thapasigargin. Collectively, these results reveal that potentiation of adaptation to chronic ER stress is another mechanism by which oncogenic activation of the MEK/ERK pathway promotes the pathogenesis of melanoma.
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19
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Jiang CC, Croft A, Tseng HY, Guo ST, Jin L, Hersey P, Zhang XD. Repression of microRNA-768-3p by MEK/ERK signalling contributes to enhanced mRNA translation in human melanoma. Oncogene 2013; 33:2577-88. [PMID: 23770856 DOI: 10.1038/onc.2013.237] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 04/08/2013] [Accepted: 04/08/2013] [Indexed: 12/11/2022]
Abstract
Increased global protein synthesis and selective translation of mRNAs encoding proteins contributing to malignancy is common in cancer cells. This is often associated with elevated expression of eukaryotic translation initiation factor 4 (eIF4E), the rate-limiting factor of cap-dependent translation initiation. We report here that in human melanoma downregulation of miR-768-3p as a result of activation of the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway has an important role in the upregulation of eIF4E and enhancement in protein synthesis. Melanoma cells displayed increased nascent protein production and elevated eIF4E expression, which was associated with the downregulation of miR-768-3p that was predicted to target the 3'-untranslated region of the eIF4E mRNA. Overexpression of miR-768-3p led to the downregulation of the endogenous eIF4E protein, reduction in nascent protein synthesis and inhibition of cell survival and proliferation. These effects were efficiently reversed when eIF4E was co-overexpressed in melanoma cells. On the other hand, introduction of anti-miR-768-3p into melanocytes upregulated endogenous eIF4E protein expression and increased global protein synthesis. Downregulation of miR-768-3p appeared to be mediated by activation of the MEK/ERK pathway, in that treatment of BRAF(V600E) melanoma cells with the mutant BRAF inhibitor PLX4720 or exposure of either BRAF(V600E) or wild-type BRAF melanoma cells to the MEK inhibitor U0126 resulted in the upregulation of miR-768-3p and inhibition of nascent protein synthesis. This inhibition was partially blocked in cells cointroduced with anti-miR-768-3p. Significantly, miR-768-3p was similarly downregulated, which was inversely associated with the expression levels of eIF4E in fresh melanoma isolates. Taken together, these results identify downregulation of miR-768-3p and subsequent upregulation of eIF4E as an important mechanism in addition to phosphorylation of eIF4E responsible for MEK/ERK-mediated enhancement of protein synthesis in melanoma.
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Affiliation(s)
- C C Jiang
- 1] Priority Research Centre for Cancer Research, University of Newcastle, Callaghan, NSW, Australia [2] School of Medicine and Public Health, University of Newcastle, Callaghan, NSW, Australia
| | - A Croft
- 1] Priority Research Centre for Cancer Research, University of Newcastle, Callaghan, NSW, Australia [2] Oncology and Immunology Unit, Calvary Mater Newcastle Hospital, Waratah, NSW, Australia
| | - H-Y Tseng
- 1] Priority Research Centre for Cancer Research, University of Newcastle, Callaghan, NSW, Australia [2] School of Medicine and Public Health, University of Newcastle, Callaghan, NSW, Australia
| | - S T Guo
- Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Taiyuan, Shanxi, People's Republic of China
| | - L Jin
- Kolling Institute for Medical Research, University of Sydney, St Leonards, NSW, Australia
| | - P Hersey
- Kolling Institute for Medical Research, University of Sydney, St Leonards, NSW, Australia
| | - X D Zhang
- 1] Priority Research Centre for Cancer Research, University of Newcastle, Callaghan, NSW, Australia [2] School of Medicine and Public Health, University of Newcastle, Callaghan, NSW, Australia [3] Department of Molecular Biology, Shanxi Cancer Hospital and Institute, Taiyuan, Shanxi, People's Republic of China
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