51
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Galeterone and The Next Generation Galeterone Analogs, VNPP414 and VNPP433-3β Exert Potent Therapeutic Effects in Castration-/Drug-Resistant Prostate Cancer Preclinical Models In Vitro and In Vivo. Cancers (Basel) 2019; 11:cancers11111637. [PMID: 31653008 PMCID: PMC6895912 DOI: 10.3390/cancers11111637] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/03/2019] [Accepted: 10/18/2019] [Indexed: 12/16/2022] Open
Abstract
These studies compared the efficacies of our clinical agent galeterone (Gal) and the FDA-approved prostate cancer drug, enzalutamide (ENZ) with two lead next generation galeterone analogs (NGGAs), VNPP414 and VNPP433-3β, using prostate cancer (PC) in vitro and in vivo models. Antitumor activities of orally administered agents were also assessed in CWR22Rv1 tumor-bearing mice. We demonstrated that Gal and NGGAs degraded AR/AR-V7 and Mnk1/2; blocked cell cycle progression and proliferation of human PC cells; induced apoptosis; inhibited cell migration, invasion, and putative stem cell markers; and reversed the expression of epithelial-to-mesenchymal transition (EMT). In addition, Gal/NGGAs (alone or in combination) also inhibited the growth of ENZ-, docetaxel-, and mitoxantrone-resistant human PC cell lines. The NGGAs exhibited improved pharmacokinetic profiles over Gal in mice. Importantly, in vivo testing showed that VNPP433-3β (at 7.53-fold lower equimolar dose than Gal) markedly suppressed (84% vs. Gal, 47%; p < 0.01) the growth of castration-resistant PC (CRPC) CWR22Rv1 xenograft tumors, with no apparent host toxicity. ENZ was ineffective in this CRPC xenograft model. In summary, our findings show that targeting AR/AR-V7 and Mnk1/2 for degradation represents an effective therapeutic strategy for PC/CRPC treatment and supports further development of VNPP433-3β towards clinical investigation.
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52
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Proud CG. Phosphorylation and Signal Transduction Pathways in Translational Control. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a033050. [PMID: 29959191 DOI: 10.1101/cshperspect.a033050] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein synthesis, including the translation of specific messenger RNAs (mRNAs), is regulated by extracellular stimuli such as hormones and by the levels of certain nutrients within cells. This control involves several well-understood signaling pathways and protein kinases, which regulate the phosphorylation of proteins that control the translational machinery. These pathways include the mechanistic target of rapamycin complex 1 (mTORC1), its downstream effectors, and the mitogen-activated protein (MAP) kinase (extracellular ligand-regulated kinase [ERK]) signaling pathway. This review describes the regulatory mechanisms that control translation initiation and elongation factors, in particular the effects of phosphorylation on their interactions or activities. It also discusses current knowledge concerning the impact of these control systems on the translation of specific mRNAs or subsets of mRNAs, both in physiological processes and in diseases such as cancer.
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Affiliation(s)
- Christopher G Proud
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide SA5000, Australia; and School of Biological Sciences, University of Adelaide, Adelaide SA5000, Australia
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53
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Ichiyanagi O, Ito H, Naito S, Kabasawa T, Kanno H, Narisawa T, Ushijima M, Kurota Y, Ozawa M, Sakurai T, Nishida H, Kato T, Yamakawa M, Tsuchiya N. Impact of eIF4E phosphorylation at Ser209 via MNK2a on tumour recurrence after curative surgery in localized clear cell renal cell carcinoma. Oncotarget 2019; 10:4053-4068. [PMID: 31258849 PMCID: PMC6592294 DOI: 10.18632/oncotarget.27017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/20/2019] [Indexed: 01/01/2023] Open
Abstract
Background: We investigated the roles of eIF4E phosphorylation (Ser209) in tumour recurrence after curative nephrectomy for localized clear cell renal cell carcinoma (ccRCC). Methods: Expression of eIF4E, p eIF4E and MNKs (MAPK interacting kinases), was evaluated in surgical specimens obtained from consecutive non metastatic ccRCC patients (n = 290) by immunohistochemistry (IHC), immunoblotting, and qRT PCR at the protein and mRNA levels. In human RCC cell lines, the effects of eIF4E phosphorylation were examined using immunoblotting, proliferation, migration and invasion assays with pharmacological inhibitors (CGP57380 or ETP45835) and specific small interfering (si) RNAs against MNK1/2(a/b). Results: In postoperative follow-up (median, 7.9 y), 40 patients experienced metastatic recurrence. In multivariate Cox analyses, higher IHC expression of p eIF4E in ccRCC significantly predicted a longer recurrence-free interval. eIF4E is phosphorylated mainly by MNK2a in tumour specimens and cell lines. In 786-O and A-498 cell lines, pharmacological inhibition of MNKs decreased p-eIF4E and increased vimentin and N cadherin but did not influence proliferation. Similarly, MNK2 or MNK2a inhibition with siRNA reduced p-eIF4E and enhanced vimentin translation, cell migration and invasion in the cell lines. Conclusions: MNK2a-induced eIF4E phosphorylation may suppress metastatic recurrence of ccRCC, partially due to vimentin downregulation at the translational level, consequently leading to inhibition of epithelial–mesenchymal transition.
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Affiliation(s)
- Osamu Ichiyanagi
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan.,Department of Urology, Yamagata Prefectural Kahoku Hospital, Kahoku, Japan
| | - Hiromi Ito
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Sei Naito
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Takanobu Kabasawa
- Department of Pathological Diagnostics, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Hidenori Kanno
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Takafumi Narisawa
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Masaki Ushijima
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Yuta Kurota
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Michinobu Ozawa
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Toshihiko Sakurai
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Hayato Nishida
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Tomoyuki Kato
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Mitsunori Yamakawa
- Department of Pathological Diagnostics, Yamagata University Faculty of Medicine, Yamagata, Japan
| | - Norihiko Tsuchiya
- Department of Urology, Yamagata University Faculty of Medicine, Yamagata, Japan
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54
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G3BP1 and G3BP2 regulate translation of interferon-stimulated genes: IFITM1, IFITM2 and IFITM3 in the cancer cell line MCF7. Mol Cell Biochem 2019; 459:189-204. [PMID: 31172368 DOI: 10.1007/s11010-019-03562-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 05/27/2019] [Indexed: 12/13/2022]
Abstract
G3BPs are members of an RNA-binding protein family and their aberrant expression is common in various cancers and there is growing evidence that G3BPs possess antiviral activities and are targeted by various viruses. G3BPs have also been implicated in both stabilization and degradation of specific mRNAs as well as translational control of mRNA targets. G3BPs have been shown to control translation of interferon-stimulated genes (ISGs), implying that G3BPs are involved in the regulation of the interferon system in response to viral infections and/or cellular stress. The interferon induced transmembrane (IFITM1, IFITM2 and IFITM3) proteins are antiviral proteins, and are also involved in cancer progression and metastasis. Therefore, these genes were selected in the studies reported here as potential transcript targets of G3BPs. Furthermore, G3BPs are involved in the regulation of the MEK pathway which also impacts on the translation of ISGs. Therefore, the role of this pathway was also analysed in regulation of IFITM1-3 proteins. Overall, this research study suggests that G3BPs are essential for the accumulation of IFITM1-3 proteins and intersect twice in the regulation of IFITM1-3 expression, first through MEK pathway and then through an interaction with the 3'-UTRs of its target transcripts. However, it is still to be determined whether the two apparent functions are part of a single control mechanism or the two functions are mutually exclusive.
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55
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Bruns AN, Li S, Mohannath G, Bisaro DM. Phosphorylation of Arabidopsis eIF4E and eIFiso4E by SnRK1 inhibits translation. FEBS J 2019; 286:3778-3796. [PMID: 31120171 DOI: 10.1111/febs.14935] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/28/2019] [Accepted: 05/21/2019] [Indexed: 01/01/2023]
Abstract
Regulation of protein synthesis is critical for maintaining cellular homeostasis. In mammalian systems, translational regulatory networks have been elucidated in considerable detail. In plants, however, regulation occurs through different mechanisms that remain largely elusive. In this study, we present evidence that the Arabidopsis thaliana energy sensing kinase SnRK1, a homologue of mammalian AMP-activated kinase and yeast sucrose non-fermenting 1 (SNF1), inhibits translation by phosphorylating the cap binding proteins eIF4E and eIFiso4E. We establish that eIF4E and eIFiso4E contain two deeply conserved SnRK1 consensus target sites and that both interact with SnRK1 in vivo. We then demonstrate that SnRK1 phosphorylation inhibits the ability of Arabidopsis eIF4E and eIFiso4E to complement a yeast strain lacking endogenous eIF4E, and that inhibition correlates with repression of polysome formation. Finally, we show that SnRK1 over-expression in Nicotiana benthamiana plants reduces polysome formation, and that this effect can be counteracted by transient expression of eIF4E or mutant eIF4E containing non-phosphorylatable SnRK1 target residues, but not by a phosphomimic eIF4E. Together, these studies elucidate a novel and direct pathway for translational control in plant cells. In light of previous findings that SnRK1 conditions an innate antiviral defense and is inhibited by geminivirus pathogenicity factors, we speculate that phosphorylation of cap binding proteins may be a component of the resistance mechanism.
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Affiliation(s)
- Aaron N Bruns
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH, USA.,Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
| | - Sizhun Li
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH, USA
| | - Gireesha Mohannath
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH, USA
| | - David M Bisaro
- Department of Molecular Genetics, Center for Applied Plant Sciences, Center for RNA Biology, and Infectious Diseases Institute, The Ohio State University, Columbus, OH, USA.,Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, USA
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56
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Frosi Y, Usher R, Lian DTG, Lane DP, Brown CJ. Monitoring flux in signalling pathways through measurements of 4EBP1-mediated eIF4F complex assembly. BMC Biol 2019; 17:40. [PMID: 31118010 PMCID: PMC6530213 DOI: 10.1186/s12915-019-0658-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 04/29/2019] [Indexed: 01/10/2023] Open
Abstract
Background The most commonly occurring cancer mutations, including oncogenes such as MYC, Ras and PIK3C, are found in signal transductions pathways feeding into the translational machinery. A broad range of translation initiation factors are also commonly found to be either amplified or mis-regulated in tumours, including eIF4E (elongation initiation factor 4E). eIF4E is a subunit of the eIF4F protein initiation complex and required for its recruitment. Here we measure the formation of the eIF4F complex through interactions of eIF4E and eIF4G subunits, and the effect of oncogenic signalling pathways on complex formation. Results We developed a protein fragment complementation (PCA) assay that can accurately measure the status of the eIF4E-eIF4G interaction in cells and quantify the signalling flux through the RAS/ERK and PI3K/AKT pathways regulating eIF4F assembly. Complex disruption induced by inhibition of either pathway was shown to be a function of the phosphorylation status of 4EBP1, a key mediator of eIF4F assembly that interacts directly with eIF4E, confirming 4EBP1’s ability to integrate multiple signals affecting cap-dependent translation. Maximal measured disruption of the eIF4F complex occurred under combined mTORC1 and mTORC2 inhibition, whilst combined inhibition of both RAS/ERK and PI3K/AKT pathways in parallel resulted in greater inhibition of eIF4F formation than individually. v-Myc-mediated resistance to dual mTORC/PI3K inhibition was also principally demonstrated to depend on the lack of competent 4EBP1 available in the cell to bind eIF4E. Conclusions We show that 4EBP1 is a critical regulator of the mitogen responsive RAS/ERK and PI3K/AKT pathways and a key transducer of resistance mechanisms that affect small molecule inhibition of these pathways, principally by attenuating their effects on cap-dependent translation. These findings highlight the importance of highly efficacious direct inhibitors of eIF4E and eIF4F assembly, which could potentially target a wide spectrum of tumours containing differing mutations that effect these pathways and which confer chemo-resistance. Electronic supplementary material The online version of this article (10.1186/s12915-019-0658-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yuri Frosi
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore
| | - Rachael Usher
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore
| | - Dawn Thean Gek Lian
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore
| | - David P Lane
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore
| | - Christopher J Brown
- p53 Laboratory, A*STAR (Agency for Science, Technology and Research), 8A Biomedical Grove, #06-04/05, Neuros/Immunos, Singapore, 138648, Singapore.
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57
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Zhu ZC, Liu JW, Yang C, Zhao M, Xiong ZQ. XPO1 inhibitor KPT-330 synergizes with Bcl-xL inhibitor to induce cancer cell apoptosis by perturbing rRNA processing and Mcl-1 protein synthesis. Cell Death Dis 2019; 10:395. [PMID: 31113936 PMCID: PMC6529444 DOI: 10.1038/s41419-019-1627-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Revised: 04/02/2019] [Accepted: 04/08/2019] [Indexed: 01/19/2023]
Abstract
XPO1 (exportin1) mediates nuclear export of proteins and RNAs and is frequently overexpressed in cancers. In this study, we show that the orally bioavailable XPO1 inhibitor KPT-330 reduced Mcl-1 protein level, by which it synergized with Bcl-xL inhibitor A-1331852 to induce apoptosis in cancer cells. KPT-330/A-1331852 combination disrupted bindings of Mcl-1 and Bcl-xL to Bax, Bak, and/or Bim, elicited mitochondrial outer membrane permeabilization, and triggered apoptosis. KPT-330 generally mitigated mRNA expression and protein synthesis rather than mRNA nuclear export or protein stability of Mcl-1. KPT-330 inhibited mTORC1/4E-BP1 and Mnk1/eIF4E axes, which disrupted the eIF4F translation initiation complex but was dispensable for Mcl-1 reduction and KPT-330/A-1331852 combination-induced apoptosis. Mature rRNAs are integral components of the ribosome that determines protein synthesis ability. KPT-330 impeded nucleolar rRNA processing and reduced total levels of multiple mature rRNAs. Reconstitution of XPO1 by expressing degradation-resistant C528S mutant retained rRNA amount, Mcl-1 expression, and Bcl-xL inhibitor resistance upon KPT-330 treatment. KPT-330/A-1331852 combination suppressed growth and enhanced apoptosis of non-small cell lung cancer xenografts. Therefore, we clarify the reason of apoptosis resistance of cancer cells to XPO1 inhibition and develop a potential strategy for treating solid tumors.
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MESH Headings
- Animals
- Antineoplastic Agents/pharmacology
- Antineoplastic Agents/therapeutic use
- Apoptosis/drug effects
- Benzothiazoles/pharmacology
- Benzothiazoles/therapeutic use
- Carcinoma, Non-Small-Cell Lung/drug therapy
- Carcinoma, Non-Small-Cell Lung/metabolism
- Carcinoma, Non-Small-Cell Lung/pathology
- Cell Line, Tumor
- Down-Regulation/drug effects
- Drug Synergism
- Eukaryotic Initiation Factor-4F/metabolism
- Humans
- Hydrazines/pharmacology
- Hydrazines/therapeutic use
- Isoquinolines/pharmacology
- Isoquinolines/therapeutic use
- Karyopherins/antagonists & inhibitors
- Karyopherins/genetics
- Karyopherins/metabolism
- Lung Neoplasms/drug therapy
- Lung Neoplasms/metabolism
- Lung Neoplasms/pathology
- Male
- Mechanistic Target of Rapamycin Complex 1/metabolism
- Mice
- Mice, Inbred NOD
- Mice, SCID
- Myeloid Cell Leukemia Sequence 1 Protein/antagonists & inhibitors
- Myeloid Cell Leukemia Sequence 1 Protein/genetics
- Myeloid Cell Leukemia Sequence 1 Protein/metabolism
- RNA, Ribosomal/metabolism
- Receptors, Cytoplasmic and Nuclear/antagonists & inhibitors
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Triazoles/pharmacology
- Triazoles/therapeutic use
- Exportin 1 Protein
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Affiliation(s)
- Zhi-Chuan Zhu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Ji-Wei Liu
- Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Can Yang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Miao Zhao
- Department of Neurology and Institute of Neurology, The First Affiliated Hospital of Fujian Medical University, Fuzhou, China
| | - Zhi-Qi Xiong
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.
- University of Chinese Academy of Sciences, Beijing, China.
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
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58
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Volpon L, Osborne MJ, Borden KL. Biochemical and Structural Insights into the Eukaryotic Translation Initiation Factor eIF4E. Curr Protein Pept Sci 2019; 20:525-535. [DOI: 10.2174/1389203720666190110142438] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/26/2018] [Accepted: 01/04/2019] [Indexed: 12/18/2022]
Abstract
A major question in cell and cancer biology is concerned with understanding the flow of
information from gene to protein. Indeed, many studies indicate that the proteome can be decoupled
from the transcriptome. A major source of this decoupling is post-transcriptional regulation. The eukaryotic
translation initiation factor eIF4E serves as an excellent example of a protein that can modulate
the proteome at the post-transcriptional level. eIF4E is elevated in many cancers thus highlighting
the relevance of this mode of control to biology. In this review, we provide a brief overview of various
functions of eIF4E in RNA metabolism e.g. in nuclear-cytoplasmic RNA export, translation,
RNA stability and/or sequestration. We focus on the modalities of eIF4E regulation at the biochemical
and particularly structural level. In this instance, we describe not only the importance for the m7Gcap
eIF4E interaction but also of recently discovered non-traditional RNA-eIF4E interactions as well
as cap-independent activities of eIF4E. Further, we describe several distinct structural modalities used
by the cell and some viruses to regulate or co-opt eIF4E, substantially extending the types of proteins
that can regulate eIF4E from the traditional eIF4E-binding proteins (e.g. 4E-BP1 and eIF4G). Finally,
we provide an overview of the results of targeting eIF4E activity in the clinic.
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Affiliation(s)
- Laurent Volpon
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Universite de Montreal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, Quebec, Canada
| | - Michael J. Osborne
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Universite de Montreal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, Quebec, Canada
| | - Katherine L.B. Borden
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Universite de Montreal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, Quebec, Canada
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59
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Batool A, Aashaq S, Andrabi KI. Eukaryotic initiation factor 4E (eIF4E): A recap of the cap-binding protein. J Cell Biochem 2019; 120:14201-14212. [PMID: 31074051 DOI: 10.1002/jcb.28851] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 04/09/2019] [Accepted: 04/11/2019] [Indexed: 12/29/2022]
Abstract
Eukaryotic initiation factor 4E (eIF4E), a fundamental effector and rate limiting element of protein synthesis, binds the 7-methylguanosine cap at the 5' end of eukaryotic messenger RNA (mRNA) specifically as a constituent of eIF4F translation initiation complex thus facilitating the recruitment of mRNA to the ribosomes. This review focusses on the engagement of signals contributing to growth factor originated maxim and their role in the activation of eIF4E to achieve a collective influence on cellular growth, with a key focus on conjuring vital processes like protein synthesis. The review invites considerable interest in elevating the appeal of eIF4E beyond its role in regulating translation viz a viz cancer genesis, attributed to its phosphorylation state that improves the prospect for the growth of the cancerous cell. This review highlights the latest studies that have envisioned to target these pathways and ultimately the translational machinery for therapeutic intervention. The review also brings forward the prospect of eIF4E to act as a converging juncture for signaling pathways like mTOR/PI3K and Mnk/MAPK to promote tumorigenesis.
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Affiliation(s)
- Asiya Batool
- Department of Biotechnology and Bioinformatics, University of Kashmir, Srinagar, Jammu and Kashmir, India
| | - Sabreena Aashaq
- Department of Biotechnology and Bioinformatics, University of Kashmir, Srinagar, Jammu and Kashmir, India
| | - Khurshid I Andrabi
- Department of Biotechnology and Bioinformatics, University of Kashmir, Srinagar, Jammu and Kashmir, India
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60
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Ramalingam S, Ramamurthy VP, Gediya LK, Murigi FN, Purushottamachar P, Huang W, Choi EY, Zhang Y, Vasaitis TS, Kane MA, Lapidus RG, Njar VCO. The Novel Mnk1/2 Degrader and Apoptosis Inducer VNLG-152 Potently Inhibits TNBC Tumor Growth and Metastasis. Cancers (Basel) 2019; 11:cancers11030299. [PMID: 30832411 PMCID: PMC6468747 DOI: 10.3390/cancers11030299] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 02/22/2019] [Accepted: 02/26/2019] [Indexed: 12/17/2022] Open
Abstract
Currently, there are no effective therapies for patients with triple-negative breast cancer (TNBC), an aggressive and highly metastatic disease. Activation of eukaryotic initiation factor 4E (eIF4E) by mitogen-activated protein kinase (MAPK)-interacting kinases 1 and 2 (Mnk1/2) play a critical role in the development, progression and metastasis of TNBC. Herein, we undertook a comprehensive study to evaluate the activity of a first-in-class Mnk1/2 protein degraders, racemic VNLG-152R and its two enantiomers (VNLG-152E1 and VNLG-152E2) in in vitro and in vivo models of TNBC. These studies enabled us to identify racemic VNLG-152R as the most efficacious Mnk1/2 degrader, superior to its pure enantiomers. By targeting Mnk1/2 protein degradation (activity), VNLG-152R potently inhibited both Mnk-eIF4E and mTORC1 signaling pathways and strongly regulated downstream factors involved in cell cycle regulation, apoptosis, pro-inflammatory cytokines/chemokines secretion, epithelial-mesenchymal transition (EMT) and metastasis. Most importantly, orally bioavailable VNLG-152R exhibited remarkable antitumor (91 to 100% growth inhibition) and antimetastatic (~80% inhibition) activities against cell line and patient-derived TNBC xenograft models, with no apparent host toxicity. Collectively, these studies demonstrate that targeting Mnk-eIF4E/mTORC1 signaling with a potent Mnk1/2 degrader, VNLG-152R, is a novel therapeutic strategy that can be developed as monotherapy for the effective treatment of patients with primary/metastatic TNBC.
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Affiliation(s)
- Senthilmurugan Ramalingam
- Department of Pharmacology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
| | - Vidya P Ramamurthy
- Department of Pharmacology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
| | - Lalji K Gediya
- Department of Pharmacology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
| | - Francis N Murigi
- Department of Pharmacology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
| | - Puranik Purushottamachar
- Department of Pharmacology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
| | - Weiliang Huang
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201-1559, USA.
| | - Eun Yong Choi
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
| | - Yuji Zhang
- Division of Biostatistics and Bioinformatics, University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center, Baltimore, MD 21201-1559, USA.
- Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | - Tadas S Vasaitis
- Department of Pharmaceutical Sciences, School of Pharmacy and Health Professions, University of Maryland Eastern Shore, 207 Somerset Hall, Princess Anne, MD 21853, USA.
| | - Maureen A Kane
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201-1559, USA.
| | - Rena G Lapidus
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
| | - Vincent C O Njar
- Department of Pharmacology, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
- Center for Biomolecular Therapeutics, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD 21201, USA.
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61
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Xie J, Merrett JE, Jensen KB, Proud CG. The MAP kinase-interacting kinases (MNKs) as targets in oncology. Expert Opin Ther Targets 2019; 23:187-199. [DOI: 10.1080/14728222.2019.1571043] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Jianling Xie
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - James E. Merrett
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Kirk B. Jensen
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, Adelaide, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Christopher G. Proud
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, Adelaide, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, Australia
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Jin X, Merrett J, Tong S, Flower B, Xie J, Yu R, Tian S, Gao L, Zhao J, Wang X, Jiang T, Proud CG. Design, synthesis and activity of Mnk1 and Mnk2 selective inhibitors containing thieno[2,3-d]pyrimidine scaffold. Eur J Med Chem 2018; 162:735-751. [PMID: 30496989 DOI: 10.1016/j.ejmech.2018.10.070] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 10/25/2018] [Accepted: 10/31/2018] [Indexed: 01/10/2023]
Abstract
The mitogen-activated protein kinase-interacting kinases 1 and 2 (MNK1 and MNK2) phosphorylate eukaryotic initiation factor 4E (eIF4E) and play important roles in promoting tumorigenesis and metabolic disease. Thus, inhibiting these enzymes might be valuable in the treatment of such conditions. We designed and synthesized a series of 4-((4-fluoro-2-isopropoxyphenyl)amino)-5-methylthieno[2,3-d]pyrimidine derivatives, and evaluated their inhibitory activity against the MNKs. We found 15 compounds that were active as MNK inhibitors and that one in particular, designated MNK-7g, which was potent against MNK1 and substantially more potent against MNK2. The compound MNK-7g did not affect other signaling pathways tested and had no adverse effects on cell viability. As expected from earlier studies, MNK-7g also inhibited cell migration. Therefore, the compound MNK-7g, which forms an ionic bond with Asp226 in MNK2 and possesses a substituted aniline in a thieno[2,3-d] pyrimidine structure, is a promising starting point for the future development of novel drugs for treating or managing cancer and metabolic disease.
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Affiliation(s)
- Xin Jin
- School of Medicine and Pharmacy, Ocean University of China, and Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - James Merrett
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
| | - Sheng Tong
- School of Medicine and Pharmacy, Ocean University of China, and Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Bartholomew Flower
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
| | - Jianling Xie
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
| | - Rilei Yu
- School of Medicine and Pharmacy, Ocean University of China, and Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Shuye Tian
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
| | - Ling Gao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong, China
| | - Jiajun Zhao
- Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong University, Shandong, China
| | - Xuemin Wang
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Tao Jiang
- School of Medicine and Pharmacy, Ocean University of China, and Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
| | - Christopher G Proud
- Nutrition & Metabolism, South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia.
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Meade N, DiGiuseppe S, Walsh D. Translational control during poxvirus infection. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 10:e1515. [PMID: 30381906 DOI: 10.1002/wrna.1515] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/31/2018] [Accepted: 10/01/2018] [Indexed: 02/06/2023]
Abstract
Poxviruses are an unusual family of large double-stranded (ds) DNA viruses that exhibit an incredible degree of self-sufficiency and complexity in their replication and immune evasion strategies. Indeed, amongst their approximately 200 open reading frames (ORFs), poxviruses encode approximately 100 immunomodulatory proteins to counter host responses along with complete DNA synthesis, transcription, mRNA processing and cytoplasmic redox systems that enable them to replicate exclusively in the cytoplasm of infected cells. However, like all other viruses poxviruses do not encode ribosomes and therefore remain completely dependent on gaining access to the host translational machinery in order to synthesize viral proteins. Early studies of these intriguing viruses helped discover the mRNA cap and polyadenylated (polyA) tail that we now know to be present on most eukaryotic messages and which play fundamental roles in mRNA translation, while more recent studies have begun to reveal the remarkable lengths poxviruses go to in order to control both host and viral protein synthesis. Here, we discuss some of the central strategies used by poxviruses and the broader battle that ensues with the host cell to control the translation system, the outcome of which ultimately dictates the fate of infection. This article is categorized under: Translation > Translation Regulation.
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Affiliation(s)
- Nathan Meade
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Stephen DiGiuseppe
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Derek Walsh
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
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Liong S, Lappas M. Markers of protein synthesis are increased in fetal membranes and myometrium after human labour and delivery. Reprod Fertil Dev 2018; 30:313-329. [PMID: 28701259 DOI: 10.1071/rd17081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 06/12/2017] [Indexed: 12/21/2022] Open
Abstract
Preterm birth remains one of the leading causes of neonatal death. Inflammation and maternal infection are two of the leading aetiological factors for preterm birth. Labour is associated with increased production of proinflammatory cytokines, chemokines and prolabour mediators in human gestational tissues. In non-gestational tissues, synthesis of proinflammatory and prolabour mediators is regulated by components of the protein synthesis machinery. Therefore, in the present study we investigated the effect of human labour on the expression of three protein synthesis markers, namely eukaryotic elongation factor 2 kinase (EEF2K), mitogen-activated protein kinase interacting protein kinase 1 (MKNK1) and eukaryotic translation initiation factor 4E (EIF4E), and their role in regulating inflammation in human gestational tissues. In fetal membranes and myometrium, EEF2K expression was significantly lower, whereas MKNK1 expression was significantly higher withterm and preterm labourcompared to term nolabour. In contrast, EIF4E expression did not change in fetal membranes or myometrium with labour. In primary myometrial cells, loss-of-function studies using specific chemical inhibitors of EEF2K (A484954) and MKNK1 (CGP57380) demonstrated that MKNK1, but not EEF2K, was required for polyinosinic-polycytidylic acid (poly(I:C); a viral double-stranded RNA mimetic) and interleukin (IL)-1β-induced production of IL6, C-X-C motif chemokine ligand 8 (CXCL8), prostaglandin-endoperoxide synthase 2 (PTGS2) and prostaglandin F2α. In conclusion, spontaneous term and preterm labour is associated with decreased EEF2K and increased MKNK1 expression in fetal membranes and myometrium. Moreover, MKNK1 is involved in the genesis of proinflammatory and prolabour mediators that is mediated by inflammation or infection. However, further studies are required to elucidate the role of EEF2K in human labour.
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Affiliation(s)
- Stella Liong
- Mercy Perinatal Research Centre, Mercy Hospital for Women, 4th Floor, 163 Studley Road, Heidelberg, Vic. 3084, Australia
| | - Martha Lappas
- Mercy Perinatal Research Centre, Mercy Hospital for Women, 4th Floor, 163 Studley Road, Heidelberg, Vic. 3084, Australia
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Kolupaeva V. Serine-threonine protein phosphatases: Lost in translation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2018; 1866:83-89. [PMID: 30401537 DOI: 10.1016/j.bbamcr.2018.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/26/2018] [Accepted: 08/08/2018] [Indexed: 12/17/2022]
Abstract
Protein synthesis is one of the most complex and energy-consuming processes in eukaryotic cells and therefore is tightly regulated. One of the main mechanisms of translational control is post-translational modifications of the components of translational apparatus. Phosphorylation status of translation factors depends on the balanced action of kinases and phosphatases. While many kinase-dependent events are well defined, phosphatases that counteract phosphorylation are rarely determined. This mini-review focuses on the regulation of activity of translational initiation factors by serine/threonine phosphatases.
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Affiliation(s)
- Victoria Kolupaeva
- NYU College of Dentistry, Department of Basic Science and Craniofacial Biology, 345 E 24th St, New York, NY 10010, United States of America.
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Shaw LC, Li Calzi S, Li N, Moldovan L, Sengupta-Caballero N, Quigley JL, Ivan M, Jun B, Bazan NG, Boulton ME, Busik J, Neu J, Grant MB. Enteral Arg-Gln Dipeptide Administration Increases Retinal Docosahexaenoic Acid and Neuroprotectin D1 in a Murine Model of Retinopathy of Prematurity. Invest Ophthalmol Vis Sci 2018; 59:858-869. [PMID: 29490339 PMCID: PMC5815421 DOI: 10.1167/iovs.17-23034] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Low levels of the long chain polyunsaturated fatty acid (LCPUFA) docosahexaenoic acid (DHA) have been implicated in retinopathy of prematurity (ROP). However, oral DHA suffers from poor palatability and is associated with increased bleeding in premature infants. We asked whether oral administration of the neutraceutical arginine-glutamine (Arg-Glu) could increase retinal DHA and improve outcomes in a mouse model of oxygen-induced retinopathy (OIR). Methods Postnatal day 7 (P7) pups were maintained at 75% oxygen for 5 days and then returned to room air on P12. Pups were gavaged twice daily with Arg-Gln or vehicle from P12 to P17 and eyes were harvested for analysis on P17. Vaso-obliteration and vascular density were assessed on retinal flat mounts and preretinal neovascularization was assessed on retinal cross sections. Retinas were used for measurement of DHA and 10,17S-docosatriene (neuroprotectin D1, NPD1), a key DHA-derived lipid, and for analysis by reverse-phase protein array (RPPA). Results With Arg-Gln treatment, retinal DHA and NPD1 levels were increased in OIR pups. Arg-Gln reduced preretinal neovascularization by 39 ± 6% (P < 0.05) relative to vehicle control. This was accompanied by a restoration of vascular density of the retina in the pups treated with Arg-Gln (73.0 ± 3.0%) compared to vehicle (53.1 ± 3.4%; P < 0.05). Arg-Gln dipeptide restored OIR-induced signaling changes toward normoxia and was associated with normalization of insulin-like growth factor receptor 1 signaling and reduction of apoptosis and an increase in anti-apoptosis proteins. Conclusions Arg-Gln may serve as a safer and easily tolerated nutraceutical agent for prevention or treatment of ROP.
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Affiliation(s)
- Lynn Calvin Shaw
- Department of Ophthalmology, Indiana University, Indianapolis, Indiana, United States
| | - Sergio Li Calzi
- Department of Ophthalmology, University of Alabama, Birmingham, Alabama, United States
| | - Nan Li
- Department of Pediatrics, University of Florida, Gainesville, Florida, United States
| | - Leni Moldovan
- Department of Ophthalmology, Indiana University, Indianapolis, Indiana, United States
| | | | | | - Mircea Ivan
- Department of Medicine, Indiana University, Indianapolis, Indiana, United States
| | - Bokkyoo Jun
- Department of Ophthalmology, Louisiana State University Eye Center, New Orleans, Louisiana, United States
| | - Nicolas G Bazan
- Department of Ophthalmology, Louisiana State University Eye Center, New Orleans, Louisiana, United States
| | - Michael Edwin Boulton
- Department of Ophthalmology, University of Alabama, Birmingham, Alabama, United States
| | - Julia Busik
- Department of Physiology, Michigan State University, East Lansing, Michigan, United States
| | - Josef Neu
- Department of Pediatrics, University of Florida, Gainesville, Florida, United States
| | - Maria B Grant
- Department of Ophthalmology, University of Alabama, Birmingham, Alabama, United States
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Peters C, Paget M, Tshilenge KT, Saha D, Antoszczyk S, Baars A, Frost T, Martuza RL, Wakimoto H, Rabkin SD. Restriction of Replication of Oncolytic Herpes Simplex Virus with a Deletion of γ34.5 in Glioblastoma Stem-Like Cells. J Virol 2018; 92:e00246-18. [PMID: 29793956 PMCID: PMC6052301 DOI: 10.1128/jvi.00246-18] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/15/2018] [Indexed: 12/12/2022] Open
Abstract
Oncolytic viruses, including herpes simplex viruses (HSVs), are a new class of cancer therapeutic engineered to infect and kill cancer cells while sparing normal tissue. To ensure that oncolytic HSV (oHSV) is safe in the brain, all oHSVs in clinical trial for glioma lack the γ34.5 genes responsible for neurovirulence. However, loss of γ34.5 attenuates growth in cancer cells. Glioblastoma (GBM) is a lethal brain tumor that is heterogeneous and contains a subpopulation of cancer stem cells, termed GBM stem-like cells (GSCs), that likely promote tumor progression and recurrence. GSCs and matched serum-cultured GBM cells (ScGCs), representative of bulk or differentiated tumor cells, were isolated from the same patient tumor specimens. ScGCs are permissive to replication and cell killing by oHSV with deletion of the γ34.5 genes (γ34.5- oHSV), while patient-matched GSCs were not, implying an underlying biological difference between stem and bulk cancer cells. GSCs specifically restrict the synthesis of HSV-1 true late (TL) proteins, without affecting viral DNA replication or transcription of TL genes. A global shutoff of cellular protein synthesis also occurs late after γ34.5- oHSV infection of GSCs but does not affect the synthesis of early and leaky late viral proteins. Levels of phosphorylated eIF2α and eIF4E do not correlate with cell permissivity. Expression of Us11 in GSCs rescues replication of γ34.5- oHSV. The difference in degrees of permissivity between GSCs and ScGCs to γ34.5- oHSV illustrates a selective translational regulatory pathway in GSCs that may be operative in other stem-like cells and has implications for creating oHSVs.IMPORTANCE Herpes simplex virus (HSV) can be genetically engineered to endow cancer-selective replication and oncolytic activity. γ34.5, a key neurovirulence gene, has been deleted in all oncolytic HSVs in clinical trial for glioma. Glioblastoma stem-like cells (GSCs) are a subpopulation of tumor cells thought to drive tumor heterogeneity and therapeutic resistance. GSCs are nonpermissive for γ34.5- HSV, while non-stem-like cancer cells from the same patient tumors are permissive. GSCs restrict true late protein synthesis, despite normal viral DNA replication and transcription of all kinetic classes. This is specific for true late translation as early and leaky late transcripts are translated late in infection, notwithstanding shutoff of cellular protein synthesis. Expression of Us11 in GSCs rescues the replication of γ34.5- HSV. We have identified a cell type-specific innate response to HSV-1 that limits oncolytic activity in glioblastoma.
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Affiliation(s)
- Cole Peters
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Program in Virology, Harvard Medical School, Boston, Massachusetts, USA
| | - Max Paget
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Program in Virology, Harvard Medical School, Boston, Massachusetts, USA
| | - Kizito-Tshitoko Tshilenge
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Dipongkor Saha
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Slawomir Antoszczyk
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Anouk Baars
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Thomas Frost
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Program in Virology, Harvard Medical School, Boston, Massachusetts, USA
| | - Robert L Martuza
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Hiroaki Wakimoto
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Samuel D Rabkin
- Brain Tumor Research Center, Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Program in Virology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts, USA
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Abstract
Translation is a key step in the regulation of gene expression and one of the most energy-consuming processes in the cell. In response to various stimuli, multiple signaling pathways converge on the translational machinery to regulate its function. To date, the roles of phosphoinositide 3-kinase (PI3K)/AKT and the mitogen-activated protein kinase (MAPK) pathways in the regulation of translation are among the best understood. Both pathways engage the mechanistic target of rapamycin (mTOR) to regulate a variety of components of the translational machinery. While these pathways regulate protein synthesis in homeostasis, their dysregulation results in aberrant translation leading to human diseases, including diabetes, neurological disorders, and cancer. Here we review the roles of the PI3K/AKT and MAPK pathways in the regulation of mRNA translation. We also highlight additional signaling mechanisms that have recently emerged as regulators of the translational apparatus.
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D'Abronzo LS, Ghosh PM. eIF4E Phosphorylation in Prostate Cancer. Neoplasia 2018; 20:563-573. [PMID: 29730477 PMCID: PMC5994774 DOI: 10.1016/j.neo.2018.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/09/2018] [Accepted: 04/10/2018] [Indexed: 12/21/2022] Open
Abstract
Prostate cancer (PCa) progression involves a shift from endocrine to paracrine and eventually autocrine control resulting from alterations in molecular mechanisms in the cells. Deregulation of RNA translation is crucial for tumor cells to grow and proliferate; therefore, overactivation of the translation machinery is often observed in cancer. The two most important signal transduction pathways regulating PCa progression are PI3K/Akt/mTOR and Ras/MAPK. These two pathways converge on the eukaryotic translation initiation factor 4E (eIF4E) which binds to the protein scaffold eIF4G upon mechanistic target of rapamycin (mTOR) activation and is phosphorylated by the mitogen-activated protein kinase (MAPK) interacting protein kinases (Mnk1/2). This review describes the role of eIF4E in mRNA translation initiation mediated by its binding to the methylated 5′ terminal structure (m7G-cap) of many mRNAs, and the ability of many tumor cells to bypass this mechanism. Hormonal therapy and chemotherapy are two of the most prevalent therapies used in patients with advanced PCa, and studies have implicated a role for eIF4E phosphorylation in promoting resistance to both these therapies. It appears that eIF4E phosphorylation enhances the rate of translation of oncogene mRNAs to increase tumorigenicity.
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Affiliation(s)
- Leandro S D'Abronzo
- VA Northern California Health Care System, Mather, CA; Department of Urological Surgery, University of California at Davis, Sacramento, CA
| | - Paramita M Ghosh
- VA Northern California Health Care System, Mather, CA; Department of Urological Surgery, University of California at Davis, Sacramento, CA; Department of Biochemistry and Molecular Medicine, University of California at Davis, Sacramento, CA.
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Tian S, Wang X, Proud CG. Oncogenic MNK signalling regulates the metastasis suppressor NDRG1. Oncotarget 2018; 8:46121-46135. [PMID: 28545025 PMCID: PMC5542254 DOI: 10.18632/oncotarget.17555] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 03/28/2017] [Indexed: 12/18/2022] Open
Abstract
The protein N-myc down-regulated gene 1 (NDRG1) represses tumour metastasis. It is phosphorylated at several sites by serum and glucocorticoid-regulated kinase 1 (SGK1). Here we show that NDRG1 is also regulated by the oncogenic MAP kinase-interacting kinase (MNK) pathway, a target for cancer therapy.Inhibiting MNKs increases the expression of NDRG1 protein and mRNA in breast cancer cells. MNK inhibition also decreases the phosphorylation of NDRG1. Phosphorylation of NDRG1 is reduced in cells lacking MNK1, but not MNK2-knockout cells, indicating that NDRG1 phosphorylation is a specific target for MNK1. However, MNK1 cannot directly phosphorylate NDRG1 in vitro, indicating that additional signalling connections are involved. Taken together, our data indicate that MNK signaling regulates NDRG1 at transcriptional and post-translational levels.We show that SGK1 phosphorylates MNK1 at a conserved site, which represses its activity. NDRG1, SGK1 and the MNKs are implicated in cell migration and metastasis. As expected, knocking-down NDRG1 promoted cell migration. However, whereas MNK inhibition impairs these processes irrespective of NDRG1 levels, SGK inhibition only did so in NDRG1-depleted cells. Thus, MNKs and SGK affect migration/invasion through distinct mechanisms.Our data reveal several novel connections between signalling pathways important for tumour biology.
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Affiliation(s)
- Shuye Tian
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide SA5000, Australia.,School of Biological Sciences, University of Adelaide, Adelaide SA5005, Australia
| | - Xuemin Wang
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide SA5000, Australia.,School of Biological Sciences, University of Adelaide, Adelaide SA5005, Australia
| | - Christopher G Proud
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide SA5000, Australia.,School of Biological Sciences, University of Adelaide, Adelaide SA5005, Australia
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71
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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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Wang X, Wang Y, Zhang Q, Zhuang H, Chen B. MAP Kinase-Interacting Kinase 1 Promotes Proliferation and Invasion of Hepatocellular Carcinoma and Is an Unfavorable Prognostic Biomarker. Med Sci Monit 2018; 24:1759-1767. [PMID: 29576605 PMCID: PMC5885772 DOI: 10.12659/msm.909012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Background Hepatocellular carcinoma (HCC) accounts for one of the most prevalent tumor types in the world. The MAP kinase-interacting kinase 1 (MNK1) functions downstream of MAP kinases such as p38 and ERK, and its potential role in cancer development is being uncovered. The aim of this study was to investigate the expression and function of MNK1 in HCC. Material/Methods Immunohistochemical staining and quantitative PCR were performed to explore the expression of MNK1 in both HCC tissues and adjacent normal liver tissues. Chi-square test, univariate analysis, and multivariate analysis were conducted to statistically evaluate clinical significance of MNK1 in HCC. Proliferation, migration, and invasion capacities of HCC cells were assessed after overexpressing or silencing MNK1. Results Both the RNA and protein levels of MNK1 were upregulated in HCC tissues compared to normal liver tissues. High expression of MNK1 was correlated with advanced tumor stage and poor overall survival. Moreover, MNK1 was identified as a novel independent prognostic factor for HCC patients. Cellular studies showed that MNK1 can enhance the proliferation, migration, and invasion capacities of HCC cells, thereby promoting tumor progression. Conclusions High expression of MNK1 is frequent in HCC tissues, which promotes tumor proliferation and invasion, and is correlated with a poor overall survival. Targeting MNK1 may be a novel direction for the drug development of HCC therapy.
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Affiliation(s)
- Xujing Wang
- Department of Hepatopancreatobiliary Surgery, East Hospital Affiliated to Tongji University in Shanghai, Shanghai, China (mainland)
| | - Yongkun Wang
- Department of Hepatopancreatobiliary Surgery, East Hospital Affiliated to Tongji University in Shanghai, Shanghai, China (mainland)
| | - Qiqi Zhang
- Department of Hepatopancreatobiliary Surgery, East Hospital Affiliated to Tongji University in Shanghai, Shanghai, China (mainland)
| | - Huiren Zhuang
- Department of Hepatopancreatobiliary Surgery, East Hospital Affiliated to Tongji University in Shanghai, Shanghai, China (mainland)
| | - Bo Chen
- Department of Hepatopancreatobiliary Surgery, East Hospital Affiliated to Tongji University in Shanghai, Shanghai, China (mainland)
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Kong SY, Kim W, Lee HR, Kim HJ. The histone demethylase KDM5A is required for the repression of astrocytogenesis and regulated by the translational machinery in neural progenitor cells. FASEB J 2018; 32:1108-1119. [PMID: 29212818 PMCID: PMC6266631 DOI: 10.1096/fj.201700780r] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/27/2017] [Indexed: 01/20/2023]
Abstract
Histone demethylases are known to play important roles in the determination of the fate of stem cells and in cancer progression. In this study, we show that the lysine 4 of histone H3 (H3K4), lysine-specific demethylase 5A (KDM5A) is essential for the repression of astrocyte differentiation in neural progenitor cells (NPCs), and its expression is regulated by translational machinery. Knockdown of KDM5A in NPCs increased astrocytogenesis, and conversely, KDM5A overexpression reduced the transcriptional activity of the Gfap promoter. Induction of astrocytogenesis by ciliary neurotrophic factor (CNTF) or small interfering RNA-induced knockdown of KDM5A decreased KDM5A recruitment to the Gfap promoter and increased H3K4 methylation. The transcript level of Kdm5a was high, whereas KDM5A protein level was low in CNTF induced astrocytes. During astroglial differentiation, translational activity indicated by the phosphorylation of eukaryotic translation initiation factor (eIF)4E was decreased. Treatment of NPCs with the cercosporamide, a MAPK-interacting kinases inhibitor, reduced eIF4E phosphorylation and KDM5A protein expression, increased GFAP levels, and enhanced astrocytogenesis. These data suggest that KDM5A is a key regulator that maintains NPCs in an undifferentiated state by repressing astrocytogenesis and that its expression is translationally controlled during astrocyte differentiation. Thus, KDM5A is a promising target for the modulation of NPC fate.-Kong, S.-Y., Kim, W., Lee, H.-R., Kim, H.-J. The histone demethylase KDM5A is required for the repression of astrocytogenesis and regulated by the translational machinery in neural progenitor cells.
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Affiliation(s)
- Sun-Young Kong
- Laboratory of Molecular and Stem Cell Pharmacology, College of Pharmacy,
Chung-Ang University, Seoul, South Korea
| | - Woosuk Kim
- Laboratory of Molecular and Stem Cell Pharmacology, College of Pharmacy,
Chung-Ang University, Seoul, South Korea
| | - Ha-Rim Lee
- Laboratory of Molecular and Stem Cell Pharmacology, College of Pharmacy,
Chung-Ang University, Seoul, South Korea
| | - Hyun-Jung Kim
- Laboratory of Molecular and Stem Cell Pharmacology, College of Pharmacy,
Chung-Ang University, Seoul, South Korea
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74
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The eukaryotic translation initiation factor 3 subunit E binds to classical swine fever virus NS5A and facilitates viral replication. Virology 2018; 515:11-20. [DOI: 10.1016/j.virol.2017.11.019] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 11/19/2017] [Accepted: 11/23/2017] [Indexed: 01/12/2023]
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75
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Wen Q, Wang W, Luo J, Chu S, Chen L, Xu L, Zang H, Alnemah MM, Ma J, Fan S. CGP57380 enhances efficacy of RAD001 in non-small cell lung cancer through abrogating mTOR inhibition-induced phosphorylation of eIF4E and activating mitochondrial apoptotic pathway. Oncotarget 2017; 7:27787-801. [PMID: 27050281 PMCID: PMC5053688 DOI: 10.18632/oncotarget.8497] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 03/17/2016] [Indexed: 12/21/2022] Open
Abstract
The mammalian target of rapamycin (mTOR) is a potentially important therapeutic target in a broad range of cancer types. mTOR inhibitors such as rapamycin and its analogs (rapalogs) have been proven effective as anticancer agents in non-small cell lung cancer (NSCLC), whereas they strongly enhance phosphorylation of eukaryotic translation initiation factor 4E (eIF4E) and activation of Akt, which cause resistance to mTOR-targeted therapy after an initial response. Rapamycin induces eIF4E phosphorylation by activating MAPK-interacting kinases (Mnks), and therefore targeting Mnk/eIF4E pathway represents a potential therapeutic strategy for the treatment of NSCLC. Here, our results showed that over-expression of p-Mnk1 and p-eIF4E was significantly associated with poor overall survival of NSCLC patients and high expression of p-Mnk1 might act as an independent prognostic biomarker for these patients. Meanwhile, inhibiting Mnk1 expression by Mnk inhibitor (CGP57380) could abrogate rapalogs (RAD001)-induced eIF4E phosphorylation and Akt activation. Furthermore, combination of CGP57380 and RAD001 could induce NSCLC cells apoptosis via activating intrinsic mitochondrial pathway, and exert synergistic antitumor efficacy both in vitro and in vivo. In conclusion, combination of targeting both mTOR and Mnk/eIF4E signaling pathways to enhance effectiveness of mTOR-targeted cancer therapy might be significant innovation for the personalized treatment of NSCLC.
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Affiliation(s)
- Qiuyuan Wen
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Weiyuan Wang
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Jiadi Luo
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Shuzhou Chu
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Lingjiao Chen
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Lina Xu
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Hongjing Zang
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Mohannad Ma Alnemah
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
| | - Jian Ma
- Cancer Research Institute of Central South University, Changsha, Hunan, 410078, China
| | - Songqing Fan
- Department of Pathology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, 410011, China
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76
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Translation complex profile sequencing to study the in vivo dynamics of mRNA–ribosome interactions during translation initiation, elongation and termination. Nat Protoc 2017; 12:697-731. [DOI: 10.1038/nprot.2016.189] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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77
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Levins E, Tseng CY, Patrick RM, Mayberry LK, Cole N, Browning KS. Fusion proteins of Arabidopsis cap-binding proteins: Cautionary "tails" of woe. ACTA ACUST UNITED AC 2016; 4:e1257408. [PMID: 28090423 DOI: 10.1080/21690731.2016.1257408] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 10/21/2016] [Accepted: 11/02/2016] [Indexed: 01/25/2023]
Abstract
The use of fluorescent proteins fused to other proteins has been very useful in revealing the location and function of many proteins. However, it is very important to show that the fusion of these reporter proteins does not impact the function of the protein of interest. Plants have 2 forms of the cap-binding protein that function in initiation of translation, eIF4E and a plant specific form, eIFiso4E. In an attempt to determine the cellular localization of eIFiso4E, fusions to GFP were made, but were found to not be competent to rescue the lethal phenotype of plants lacking eIF4E and eIFiso4E. This suggested that the GFP fusions at either the N- or C-terminus of eIFiso4E were not functional. Biochemical analysis of the fusions revealed that eIFiso4E•GFP fusions were not able to bind to m7GTP Sepharose indicating that they were not functional as cap-binding proteins. Analysis of eIF4E•GFP fusions, both in yeast and in vitro, showed that the N-terminal fusion may be functional, whereas the C-terminal fusion bound m7GTP Sepharose very poorly and functioned poorly in yeast. These results highlight the importance of verification both biochemically and in vivo that reporter fusions of proteins maintain activity and are stable in order to prevent observations that may result in artifacts.
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Affiliation(s)
- Elizabeth Levins
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin , Austin, TX, USA
| | - Ching-Ying Tseng
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin , Austin, TX, USA
| | - Ryan M Patrick
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin , Austin, TX, USA
| | - Laura K Mayberry
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin , Austin, TX, USA
| | - Nicola Cole
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin , Austin, TX, USA
| | - Karen S Browning
- Department of Molecular Biosciences and Institute for Cell and Molecular Biology, University of Texas at Austin , Austin, TX, USA
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78
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Bramham CR, Jensen KB, Proud CG. Tuning Specific Translation in Cancer Metastasis and Synaptic Memory: Control at the MNK-eIF4E Axis. Trends Biochem Sci 2016; 41:847-858. [PMID: 27527252 DOI: 10.1016/j.tibs.2016.07.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 07/13/2016] [Accepted: 07/14/2016] [Indexed: 02/07/2023]
Abstract
The eukaryotic translation initiation factor (eIF) 4E, which binds to the 5'-cap of mRNA, undergoes phosphorylation on a single conserved serine, executed by the mitogen-activated protein kinase (MAPK)-interacting kinases (MNKs). However, the functional consequences and physiological roles of MNK signalling have remained obscure. Now, new pharmacological and genetic tools have provided unprecedented insights into the function of MNKs and eIF4E phosphorylation. The studies suggest that MNKs control the translation of specific mRNAs in cancer metastasis and neuronal synaptic plasticity by a novel mechanism involving the regulation of the translational repressor, cytoplasmic fragile-X protein-interacting protein 1 (CYFIP1). These recent breakthroughs go a long way to resolving the longstanding enigma and controversy surrounding the function of the MNK-eIF4E axis in cancer cell biology and neurobiology.
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Affiliation(s)
- Clive R Bramham
- Department of Biomedicine and KG Jebsen Centre for Neuropsychiatric Disorders, University of Bergen, 5009 Bergen, Norway.
| | - Kirk B Jensen
- South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Christopher G Proud
- South Australian Health and Medical Research Institute, Adelaide, SA 5000, Australia; School of Biological Sciences, University of Adelaide, Adelaide, SA 5005, Australia
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79
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Zhu X, Dahlmans V, Thali R, Preisinger C, Viollet B, Voncken JW, Neumann D. AMP-activated Protein Kinase Up-regulates Mitogen-activated Protein (MAP) Kinase-interacting Serine/Threonine Kinase 1a-dependent Phosphorylation of Eukaryotic Translation Initiation Factor 4E. J Biol Chem 2016; 291:17020-7. [PMID: 27413184 DOI: 10.1074/jbc.c116.740498] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Indexed: 12/25/2022] Open
Abstract
AMP-activated protein kinase (AMPK) is a molecular energy sensor that acts to sustain cellular energy balance. Although AMPK is implicated in the regulation of a multitude of ATP-dependent cellular processes, exactly how these processes are controlled by AMPK as well as the identity of AMPK targets and pathways continues to evolve. Here we identify MAP kinase-interacting serine/threonine protein kinase 1a (MNK1a) as a novel AMPK target. Specifically, we show AMPK-dependent Ser(353) phosphorylation of the human MNK1a isoform in cell-free and cellular systems. We show that AMPK and MNK1a physically interact and that in vivo MNK1a-Ser(353) phosphorylation requires T-loop phosphorylation, in good agreement with a recently proposed structural regulatory model of MNK1a. Our data suggest a physiological role for MNK1a-Ser(353) phosphorylation in regulation of the MNK1a kinase, which correlates with increased eIF4E phosphorylation in vitro and in vivo.
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Affiliation(s)
- Xiaoqing Zhu
- From the Department of Molecular Genetics, CARIM School of Cardiovascular Diseases and
| | - Vivian Dahlmans
- Department of Molecular Genetics, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands
| | - Ramon Thali
- the Institute of Cell Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Christian Preisinger
- the Proteomics Facility, Interdisciplinary Center for Clinical Research (IZKF), RWTH University Hospital Aachen, 52074 Aachen, Germany
| | - Benoit Viollet
- the INSERM U1016, Institut Cochin, Department of Endocrinology, Metabolism and Diabetes, 75014 Paris, France, the CNRS UMR 8104, 75014 Paris, France, and the Université Paris Descartes, Sorbonne Paris Cité, 75006 Paris, France
| | - J Willem Voncken
- Department of Molecular Genetics, Maastricht University Medical Center, 6200 MD Maastricht, The Netherlands
| | - Dietbert Neumann
- From the Department of Molecular Genetics, CARIM School of Cardiovascular Diseases and the Institute of Cell Biology, ETH Zurich, 8093 Zurich, Switzerland,
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80
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Bell JB, Eckerdt FD, Alley K, Magnusson LP, Hussain H, Bi Y, Arslan AD, Clymer J, Alvarez AA, Goldman S, Cheng SY, Nakano I, Horbinski C, Davuluri RV, James CD, Platanias LC. MNK Inhibition Disrupts Mesenchymal Glioma Stem Cells and Prolongs Survival in a Mouse Model of Glioblastoma. Mol Cancer Res 2016; 14:984-993. [PMID: 27364770 DOI: 10.1158/1541-7786.mcr-16-0172] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 06/11/2016] [Indexed: 12/18/2022]
Abstract
Glioblastoma multiforme remains the deadliest malignant brain tumor, with glioma stem cells (GSC) contributing to treatment resistance and tumor recurrence. We have identified MAPK-interacting kinases (MNK) as potential targets for the GSC population in glioblastoma multiforme. Isoform-level subtyping using The Cancer Genome Atlas revealed that both MNK genes (MKNK1 and MKNK2) are upregulated in mesenchymal glioblastoma multiforme as compared with other subtypes. Expression of MKNK1 is associated with increased glioma grade and correlated with the mesenchymal GSC marker, CD44, and coexpression of MKNK1 and CD44 predicts poor survival in glioblastoma multiforme. In established and patient-derived cell lines, pharmacologic MNK inhibition using LY2801653 (merestinib) inhibited phosphorylation of the eukaryotic translation initiation factor 4E, a crucial effector for MNK-induced mRNA translation in cancer cells and a marker of transformation. Importantly, merestinib inhibited growth of GSCs grown as neurospheres as determined by extreme limiting dilution analysis. When the effects of merestinib were assessed in vivo using an intracranial xenograft mouse model, improved overall survival was observed in merestinib-treated mice. Taken together, these data provide strong preclinical evidence that pharmacologic MNK inhibition targets mesenchymal glioblastoma multiforme and its GSC population. IMPLICATIONS These findings raise the possibility of MNK inhibition as a viable therapeutic approach to target the mesenchymal subtype of glioblastoma multiforme. Mol Cancer Res; 14(10); 984-93. ©2016 AACR.
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Affiliation(s)
- Jonathan B Bell
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Frank D Eckerdt
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Kristen Alley
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Lisa P Magnusson
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Hridi Hussain
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Yingtao Bi
- Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Ahmet Dirim Arslan
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Division of Hematology/Oncology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Jessica Clymer
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Division of Hematology/Oncology/Stem Cell Transplantation, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Angel A Alvarez
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Stewart Goldman
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Division of Hematology/Oncology/Stem Cell Transplantation, Department of Pediatrics, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois
| | - Shi-Yuan Cheng
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Ichiro Nakano
- Department of Neurosurgery and Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama
| | - Craig Horbinski
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Ramana V Davuluri
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Department of Preventive Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - C David James
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Department of Neurological Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Leonidas C Platanias
- Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Division of Hematology/Oncology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Department of Medicine, Jesse Brown VA Medical Center, Chicago, Illinois.
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81
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Dodds SG, Livi CB, Parihar M, Hsu HK, Benavides AD, Morris J, Javors M, Strong R, Christy B, Hasty P, Sharp ZD. Adaptations to chronic rapamycin in mice. PATHOBIOLOGY OF AGING & AGE RELATED DISEASES 2016; 6:31688. [PMID: 27237224 PMCID: PMC4884683 DOI: 10.3402/pba.v6.31688] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 04/21/2016] [Indexed: 11/24/2022]
Abstract
Rapamycin inhibits mechanistic (or mammalian) target of rapamycin (mTOR) that promotes protein production in cells by facilitating ribosome biogenesis (RiBi) and eIF4E-mediated 5'cap mRNA translation. Chronic treatment with encapsulated rapamycin (eRapa) extended health and life span for wild-type and cancer-prone mice. Yet, the long-term consequences of chronic eRapa treatment are not known at the organ level. Here, we report our observations of chronic eRapa treatment on mTORC1 signaling and RiBi in mouse colon and visceral adipose. As expected, chronic eRapa treatment decreased detection of phosphorylated mTORC1/S6K substrate, ribosomal protein (rpS6) in colon and fat. However, in colon, contrary to expectations, there was an upregulation of 18S rRNA and some ribosomal protein genes (RPGs) suggesting increased RiBi. Among RPGs, eRapa increases rpl22l1 mRNA but not its paralog rpl22. Furthermore, there was an increase in the cap-binding protein, eIF4E relative to its repressor 4E-BP1 suggesting increased translation. By comparison, in fat, there was a decrease in the level of 18S rRNA (opposite to colon), while overall mRNAs encoding ribosomal protein genes appeared to increase, including rpl22, but not rpl22l1 (opposite to colon). In fat, there was a decrease in eIF4E relative to actin (opposite to colon) but also an increase in the eIF4E/4E-BP1 ratio likely due to reductions in 4E-BP1 at our lower eRapa dose (similar to colon). Thus, in contrast to predictions of decreased protein production seen in cell-based studies, we provide evidence that colon from chronically treated mice exhibited an adaptive 'pseudo-anabolic' state, which is only partially present in fat, which might relate to differing tissue levels of rapamycin, cell-type-specific responses, and/or strain differences.
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Affiliation(s)
- Sherry G Dodds
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Carolina B Livi
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
- Agilent Technologies, Inc., Santa Clara, CA, USA
| | - Manish Parihar
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Hang-Kai Hsu
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
- KCRB 2018, City of Hope, Duarte, CA, USA
| | - Adriana D Benavides
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Infectious Disease Research Division, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Jay Morris
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - Martin Javors
- Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Randy Strong
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Geriatric Research, Education and Clinical Center, South Texas Veterans Health Care System, San Antonio, TX, USA
| | - Barbara Christy
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
- Coagulation and Blood Research Group, US Army Institute of Surgical Research, JBSA Fort Sam Houston, TX, USA
| | - Paul Hasty
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Cancer Therapy and Research Center, San Antonio, TX, USA;
| | - Zelton Dave Sharp
- Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Cancer Therapy and Research Center, San Antonio, TX, USA;
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82
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sST2 translation is regulated by FGF2 via an hnRNP A1-mediated IRES-dependent mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2016; 1859:848-59. [PMID: 27168114 DOI: 10.1016/j.bbagrm.2016.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 04/15/2016] [Accepted: 05/05/2016] [Indexed: 11/23/2022]
Abstract
Translation is an energy-intensive process and tightly regulated. Generally, translation is initiated in a cap-dependent manner. Under stress conditions, typically found within the tumor microenvironment in association with e.g. nutrient deprivation or hypoxia, cap-dependent translation decreases, and alternative modes of translation initiation become more important. Specifically, internal ribosome entry sites (IRES) facilitate translation of specific mRNAs under otherwise translation-inhibitory conditions. This mechanism is controlled by IRES trans-acting factors (ITAF), i.e. by RNA-binding proteins, which interact with and determine the activity of selected IRESs. We aimed at characterizing the translational regulation of the IL-33 decoy receptor sST2, which was enhanced by fibroblast growth factor 2 (FGF2). We identified and verified an IRES within the 5'UTR of sST2. Furthermore, we found that MEK/ERK signaling contributes to FGF2-induced, sST2-IRES activation and translation. Determination of the sST2-5'UTR structure by in-line probing followed by deletion analyses identified 23 nucleotides within the sST2-5'UTR to be required for optimal IRES activity. Finally, we show that the RNA-binding protein heterogeneous ribonucleoprotein A1 (hnRNP A1) binds to the sST2-5'UTR, acts as an ITAF, and thus controls the activity of the sST2-IRES and consequently sST2 translation. Specifically, FGF2 enhances nuclear-cytoplasmic translocation of hnRNP A1, which requires intact MEK/ERK activity. In summary, we provide evidence that the sST2-5'UTR contains an IRES element, which is activated by a MEK/ERK-dependent increase in cytoplasmic localization of hnRNP A1 in response to FGF2, enhancing the translation of sST2.
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83
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Moore CEJ, Pickford J, Cagampang FR, Stead RL, Tian S, Zhao X, Tang X, Byrne CD, Proud CG. MNK1 and MNK2 mediate adverse effects of high-fat feeding in distinct ways. Sci Rep 2016; 6:23476. [PMID: 27087055 PMCID: PMC4834573 DOI: 10.1038/srep23476] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/07/2016] [Indexed: 02/06/2023] Open
Abstract
The MAP kinase-interacting kinases (MNK1 and MNK2) are non-essential enzymes which are activated by MAP kinases. They are implicated in controlling protein synthesis. Here we show that mice in which the expression of either MNK1 or MNK2 has been knocked out (KO) are protected against adverse effects of high-fat feeding, and in distinct ways. High-fat diet (HFD)-fed MNK2-KO show less weight gain than wild-type animals, and improved glucose tolerance, better insulin sensitivity and markedly diminished adipose tissue inflammation. This suggests MNK2 plays a role in adipogenesis and/or lipogenesis and in macrophage biology. MNK1-KO/HFD mice show better glucose tolerance and insulin sensitivity, but gain weight and show similar adipose inflammation to WT animals. These data suggest MNK1 participates in mediating HFD-induced insulin resistance. Our findings reveal distinct roles for the MNKs in a novel area of disease biology, metabolic dysfunction, and suggests they are potential new targets for managing metabolic disease.
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Affiliation(s)
- C E J Moore
- Centre for Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.,Nutrition and Metabolism, South Australian Health &Medical Research Institute, North Terrace, Adelaide, SA5000, Australia
| | - J Pickford
- Centre for Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - F R Cagampang
- Institute of Developmental Sciences, University of Southampton, Faculty of Medicine, Southampton SO16 6YD, United Kingdom
| | - R L Stead
- Centre for Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - S Tian
- Centre for Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.,Nutrition and Metabolism, South Australian Health &Medical Research Institute, North Terrace, Adelaide, SA5000, Australia
| | - X Zhao
- Nutrition and Metabolism, South Australian Health &Medical Research Institute, North Terrace, Adelaide, SA5000, Australia
| | - X Tang
- Department of Biochemistry &Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058 China
| | - C D Byrne
- Nutrition and Metabolism, University of Southampton, Faculty of Medicine, Southampton SO16 6YD, United Kingdom.,Southampton National Institute for Health Research, Biomedical Research Centre, University Hospital, Southampton, UK
| | - C G Proud
- Centre for Biological Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom.,Nutrition and Metabolism, South Australian Health &Medical Research Institute, North Terrace, Adelaide, SA5000, Australia.,School of Biological Sciences, University of Adelaide, Adelaide SA 5005, Australia
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84
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Han W, Ding Y, Xu Y, Pfister K, Zhu S, Warne B, Doyle M, Aikawa M, Amiri P, Appleton B, Stuart DD, Fanidi A, Shafer CM. Discovery of a Selective and Potent Inhibitor of Mitogen-Activated Protein Kinase-Interacting Kinases 1 and 2 (MNK1/2) Utilizing Structure-Based Drug Design. J Med Chem 2016; 59:3034-45. [DOI: 10.1021/acs.jmedchem.5b01657] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Wooseok Han
- Global
Discovery Chemistry, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Yu Ding
- Global
Discovery Chemistry, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Yongjin Xu
- Global
Discovery Chemistry, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Keith Pfister
- Global
Discovery Chemistry, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Shejin Zhu
- Global
Discovery Chemistry, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Bob Warne
- Oncology, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Mike Doyle
- Oncology, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Mina Aikawa
- Oncology, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Payman Amiri
- Oncology, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Brent Appleton
- Global
Discovery Chemistry, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Darrin D. Stuart
- Oncology, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Abdallah Fanidi
- Oncology, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
| | - Cynthia M. Shafer
- Global
Discovery Chemistry, Novartis Institutes for BioMedical Research, 4560 Horton Street, Emeryville, California 94608, United States
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85
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García-Recio EM, Pinto-Díez C, Pérez-Morgado MI, García-Hernández M, Fernández G, Martín ME, González VM. Characterization of MNK1b DNA Aptamers That Inhibit Proliferation in MDA-MB231 Breast Cancer Cells. MOLECULAR THERAPY. NUCLEIC ACIDS 2016; 5:e275. [PMID: 26730812 PMCID: PMC5012548 DOI: 10.1038/mtna.2015.50] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/19/2015] [Indexed: 02/08/2023]
Abstract
Elevated expression levels of eukaryotic initiation factor 4E (eIF4E) promote cancer development and progression. MAP kinase interacting kinases (MNKs) modulate the function of eIF4E through the phosphorylation that is necessary for oncogenic transformation. Therefore, pharmacologic MNK inhibitors may provide a nontoxic and effective anticancer strategy. MNK1b is a truncated isoform of MNK1a that is active in the absence of stimuli. Using in vitro selection, high-affinity DNA aptamers to MNK1b were selected from a library of ssDNA. Selection was monitored using the enzyme-linked oligonucleotide assay (ELONA), and the selected aptamer population was cloned and sequenced. Four groups of aptamers were identified, and the affinities of one representative for rMNK1b were determined using ELONA and quantitative polymerase chain reaction. Two aptamers, named apMNK2F and apMNK3R, had a lower Kd in the nmol/l range. The secondary structure of the selected aptamers was predicted using mFold, and the QGRS Mapper indicated the presence of potential G-quadruplex structures in both aptamers. The selected aptamers were highly specific against MNK1, showing higher affinity to MNK1b than to MNK1a. Interestingly, both aptamers were able to produce significant translation inhibition and prevent tumor cell proliferation and migration and colony formation in breast cancer cells. These results indicate that MNK1 aptamers have an attractive therapeutic potential.
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Affiliation(s)
- Eva M García-Recio
- Laboratory of Aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
| | - Celia Pinto-Díez
- Laboratory of Aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
| | - M Isabel Pérez-Morgado
- Laboratory of Aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
| | - Marta García-Hernández
- Aptus Biotech SL, c/ Faraday, 7, Parque Científico de Madrid, Campus de Cantoblanco, Madrid, Spain
| | - Gerónimo Fernández
- Aptus Biotech SL, c/ Faraday, 7, Parque Científico de Madrid, Campus de Cantoblanco, Madrid, Spain
| | - M Elena Martín
- Laboratory of Aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
| | - Víctor M González
- Laboratory of Aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain
- Laboratory of Aptamers, Servicio de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, Madrid, Spain. E-mail:
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86
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Transforming Growth Factor-β1 Induced Epithelial Mesenchymal Transition is blocked by a chemical antagonist of translation factor eIF4E. Sci Rep 2015; 5:18233. [PMID: 26678431 PMCID: PMC4683370 DOI: 10.1038/srep18233] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 11/10/2015] [Indexed: 12/22/2022] Open
Abstract
The epithelial to mesenchymal transition (EMT) imparts disease-defining properties to epithelial cells in cancer and organ fibrosis. Prior studies identify EMT control points at the level of transcription and translation, and indicate that activation of translation initiation factor 4E (eIF4E) is involved in the mechanisms coordinating these two levels of control. Here we show that 4Ei-1, a specific chemical antagonist of the eIF4E-mRNA cap interaction, potently inhibits transforming growth factor beta 1 (TGF-β1) mediated EMT in lung epithelial cells. Upon treatment with TGF-β1, we observed a rapid recruitment of Snail1 mRNA into the actively translated polysome pool accompanied by accumulation of the EMT transcription factor Snail1 in the nucleus. 4Ei-1 blocks ribosome recruitment to the Snail1 transcript thereby preventing accumulation of the Snail1 protein in the nucleus. Our findings establish an obligatory role for upstream translational control of downstream Snail1-mediated transcriptional events in TGF-β1 induced EMT, and provide proof of concept for efforts to pharmacologically modulate the eIF4E-cap interaction as a means to inhibit pathological EMT in the setting of cancer and organ fibrosis.
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87
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Korneeva NL, Song A, Gram H, Edens MA, Rhoads RE. Inhibition of Mitogen-activated Protein Kinase (MAPK)-interacting Kinase (MNK) Preferentially Affects Translation of mRNAs Containing Both a 5'-Terminal Cap and Hairpin. J Biol Chem 2015; 291:3455-67. [PMID: 26668315 DOI: 10.1074/jbc.m115.694190] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Indexed: 12/22/2022] Open
Abstract
The MAPK-interacting kinases 1 and 2 (MNK1 and MNK2) are activated by extracellular signal-regulated kinases 1 and 2 (ERK1/2) or p38 in response to cellular stress and extracellular stimuli that include growth factors, cytokines, and hormones. Modulation of MNK activity affects translation of mRNAs involved in the cell cycle, cancer progression, and cell survival. However, the mechanism by which MNK selectively affects translation of these mRNAs is not understood. MNK binds eukaryotic translation initiation factor 4G (eIF4G) and phosphorylates the cap-binding protein eIF4E. Using a cell-free translation system from rabbit reticulocytes programmed with mRNAs containing different 5'-ends, we show that an MNK inhibitor, CGP57380, affects translation of only those mRNAs that contain both a cap and a hairpin in the 5'-UTR. Similarly, a C-terminal fragment of human eIF4G-1, eIF4G(1357-1600), which prevents binding of MNK to intact eIF4G, reduces eIF4E phosphorylation and inhibits translation of only capped and hairpin-containing mRNAs. Analysis of proteins bound to m(7)GTP-Sepharose reveals that both CGP and eIF4G(1357-1600) decrease binding of eIF4E to eIF4G. These data suggest that MNK stimulates translation only of mRNAs containing both a cap and 5'-terminal RNA duplex via eIF4E phosphorylation, thereby enhancing the coupled cap-binding and RNA-unwinding activities of eIF4F.
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Affiliation(s)
- Nadejda L Korneeva
- From the Departments of Emergency Medicine and Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, and
| | - Anren Song
- Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, and
| | - Hermann Gram
- the Novartis Institute for Biomedical Research, Forum 1, CH-4002 Basel, Switzerland
| | | | - Robert E Rhoads
- Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, and
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88
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Kumar K, Chow CR, Ebine K, Arslan AD, Kwok B, Bentrem DJ, Eckerdt FD, Platanias LC, Munshi HG. Differential Regulation of ZEB1 and EMT by MAPK-Interacting Protein Kinases (MNK) and eIF4E in Pancreatic Cancer. Mol Cancer Res 2015; 14:216-27. [PMID: 26609108 DOI: 10.1158/1541-7786.mcr-15-0285] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 11/15/2015] [Indexed: 02/07/2023]
Abstract
UNLABELLED Human pancreatic ductal adenocarcinoma (PDAC) tumors are associated with dysregulation of mRNA translation. In this report, it is demonstrated that PDAC cells grown in collagen exhibit increased activation of the MAPK-interacting protein kinases (MNK) that mediate eIF4E phosphorylation. Pharmacologic and genetic targeting of MNKs reverse epithelial-mesenchymal transition (EMT), decrease cell migration, and reduce protein expression of the EMT-regulator ZEB1 without affecting ZEB1 mRNA levels. Paradoxically, targeting eIF4E, the best-characterized effector of MNKs, increases ZEB1 mRNA expression through repression of ZEB1-targeting miRNAs, miR-200c and miR-141. In contrast, targeting the MNK effector hnRNPA1, which can function as a translational repressor, increases ZEB1 protein without increasing ZEB1 mRNA levels. Importantly, treatment with MNK inhibitors blocks growth of chemoresistant PDAC cells in collagen and decreases the number of aldehyde dehydrogenase activity-positive (Aldefluor+) cells. Significantly, MNK inhibitors increase E-cadherin mRNA levels and decrease vimentin mRNA levels in human PDAC organoids without affecting ZEB1 mRNA levels. Importantly, MNK inhibitors also decrease growth of human PDAC organoids. IMPLICATIONS These results demonstrate differential regulation of ZEB1 and EMT by MNKs and eIF4E, and identify MNKs as potential targets in pancreatic cancer.
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Affiliation(s)
- Krishan Kumar
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Jesse Brown VA Medical Center, Chicago, Illinois
| | - Christina R Chow
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. The Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois
| | - Kazumi Ebine
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Jesse Brown VA Medical Center, Chicago, Illinois
| | - Ahmet D Arslan
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. The Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois
| | - Benjamin Kwok
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - David J Bentrem
- Jesse Brown VA Medical Center, Chicago, Illinois. The Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois. Department of Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Frank D Eckerdt
- The Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois
| | - Leonidas C Platanias
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Jesse Brown VA Medical Center, Chicago, Illinois. The Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois
| | - Hidayatullah G Munshi
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois. Jesse Brown VA Medical Center, Chicago, Illinois. The Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois.
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89
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Abstract
Translational control plays a critical role in the regulation of gene expression in eukaryotes and affects many essential cellular processes, including proliferation, apoptosis and differentiation. Under most circumstances, translational control occurs at the initiation step at which the ribosome is recruited to the mRNA. The eukaryotic translation initiation factor 4E (eIF4E), as part of the eIF4F complex, interacts first with the mRNA and facilitates the recruitment of the 40S ribosomal subunit. The activity of eIF4E is regulated at many levels, most profoundly by two major signalling pathways: PI3K (phosphoinositide 3-kinase)/Akt (also known and Protein Kinase B, PKB)/mTOR (mechanistic/mammalian target of rapamycin) and Ras (rat sarcoma)/MAPK (mitogen-activated protein kinase)/Mnk (MAPK-interacting kinases). mTOR directly phosphorylates the 4E-BPs (eIF4E-binding proteins), which are inhibitors of eIF4E, to relieve translational suppression, whereas Mnk phosphorylates eIF4E to stimulate translation. Hyperactivation of these pathways occurs in the majority of cancers, which results in increased eIF4E activity. Thus, translational control via eIF4E acts as a convergence point for hyperactive signalling pathways to promote tumorigenesis. Consequently, recent works have aimed to target these pathways and ultimately the translational machinery for cancer therapy.
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Affiliation(s)
- Nadeem Siddiqui
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue West, Montreal, Quebec, Canada H3A 1A3
| | - Nahum Sonenberg
- Department of Biochemistry and Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue West, Montreal, Quebec, Canada H3A 1A3
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90
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Royall E, Doyle N, Abdul-Wahab A, Emmott E, Morley SJ, Goodfellow I, Roberts LO, Locker N. Murine norovirus 1 (MNV1) replication induces translational control of the host by regulating eIF4E activity during infection. J Biol Chem 2015; 290:4748-4758. [PMID: 25561727 PMCID: PMC4335213 DOI: 10.1074/jbc.m114.602649] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Protein synthesis is a tightly controlled process responding to several stimuli, including viral infection. As obligate intracellular parasites, viruses depend on the translation machinery of the host and can manipulate it by affecting the availability and function of specific eukaryotic initiation factors (eIFs). Human norovirus is a member of the Caliciviridae family and is responsible for gastroenteritis outbreaks. Previous studies on feline calicivirus and murine norovirus 1 (MNV1) demonstrated that the viral protein, genome-linked (VPg), acts to direct translation by hijacking the host protein synthesis machinery. Here we report that MNV1 infection modulates the MAPK pathway to activate eIF4E phosphorylation. Our results show that the activation of p38 and Mnk during MNV1 infection is important for MNV1 replication. Furthermore, phosphorylated eIF4E relocates to the polysomes, and this contributes to changes in the translational state of specific host mRNAs. We propose that global translational control of the host by eIF4E phosphorylation is a key component of the host-pathogen interaction.
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Affiliation(s)
- Elizabeth Royall
- University of Surrey, Faculty of Health and Medical Sciences, School of Biosciences and Medicine, Guildford GU2 7HX, United Kingdom
| | - Nicole Doyle
- University of Surrey, Faculty of Health and Medical Sciences, School of Biosciences and Medicine, Guildford GU2 7HX, United Kingdom
| | - Azimah Abdul-Wahab
- University of Surrey, Faculty of Health and Medical Sciences, School of Biosciences and Medicine, Guildford GU2 7HX, United Kingdom
| | - Ed Emmott
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, United Kingdom
| | - Simon J Morley
- Department of Biochemistry and Molecular Biology, School of Life Sciences, University of Sussex, JMS Building, Brighton BN1 9RH, United Kingdom
| | - Ian Goodfellow
- Division of Virology, Department of Pathology, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, United Kingdom
| | - Lisa O Roberts
- University of Surrey, Faculty of Health and Medical Sciences, School of Biosciences and Medicine, Guildford GU2 7HX, United Kingdom
| | - Nicolas Locker
- University of Surrey, Faculty of Health and Medical Sciences, School of Biosciences and Medicine, Guildford GU2 7HX, United Kingdom.
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