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Sherwood DR, Kenny-Ganzert IW, Balachandar Thendral S. Translational regulation of cell invasion through extracellular matrix-an emerging role for ribosomes. F1000Res 2023; 12:1528. [PMID: 38628976 PMCID: PMC11019292 DOI: 10.12688/f1000research.143519.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/22/2023] [Indexed: 04/19/2024] Open
Abstract
Many developmental and physiological processes require cells to invade and migrate through extracellular matrix barriers. This specialized cellular behavior is also misregulated in many diseases, such as immune disorders and cancer. Cell invasive activity is driven by pro-invasive transcriptional networks that activate the expression of genes encoding numerous different proteins that expand and regulate the cytoskeleton, endomembrane system, cell adhesion, signaling pathways, and metabolic networks. While detailed mechanistic studies have uncovered crucial insights into pro-invasive transcriptional networks and the distinct cell biological attributes of invasive cells, less is known about how invasive cells modulate mRNA translation to meet the robust, dynamic, and unique protein production needs of cell invasion. In this review we outline known modes of translation regulation promoting cell invasion and focus on recent studies revealing elegant mechanisms that expand ribosome biogenesis within invasive cells to meet the increased protein production requirements to invade and migrate through extracellular matrix barriers.
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2
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Piserchio A, Long K, Browning L, Bohanon A, Isiorho E, Dalby K, Ghose R. ADP enhances the allosteric activation of eukaryotic elongation factor 2 kinase by calmodulin. Proc Natl Acad Sci U S A 2023; 120:e2300902120. [PMID: 37068230 PMCID: PMC10151598 DOI: 10.1073/pnas.2300902120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 03/06/2023] [Indexed: 04/19/2023] Open
Abstract
Protein translation, one of the most energy-consumptive processes in a eukaryotic cell, requires robust regulation, especially under energy-deprived conditions. A critical component of this regulation is the suppression of translational elongation through reduced ribosome association of the GTPase eukaryotic elongation factor 2 (eEF-2) resulting from its specific phosphorylation by the calmodulin (CaM)-activated α-kinase eEF-2 kinase (eEF-2K). It has been suggested that the eEF-2K response to reduced cellular energy levels is indirect and mediated by the universal energy sensor AMP-activated protein kinase (AMPK) through direct stimulatory phosphorylation and/or downregulation of the eEF-2K-inhibitory nutrient-sensing mTOR pathway. Here, we provide structural, biochemical, and cell-biological evidence of a direct energy-sensing role of eEF-2K through its stimulation by ADP. A crystal structure of the nucleotide-bound complex between CaM and the functional core of eEF-2K phosphorylated at its primary stimulatory site (T348) reveals ADP bound at a unique pocket located on the face opposite that housing the kinase active site. Within this basic pocket (BP), created at the CaM/eEF-2K interface upon complex formation, ADP is stabilized through numerous interactions with both interacting partners. Biochemical analyses using wild-type eEF-2K and specific BP mutants indicate that ADP stabilizes CaM within the active complex, increasing the sensitivity of the kinase to CaM. Induction of energy stress through glycolysis inhibition results in significantly reduced enhancement of phosphorylated eEF-2 levels in cells expressing ADP-binding compromised BP mutants compared to cells expressing wild-type eEF-2K. These results suggest a direct energy-sensing role for eEF-2K through its cooperative interaction with CaM and ADP.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY10031
| | - Kimberly J. Long
- Division of Chemical Biology and Medicinal Chemistry, the University of Texas, Austin, TX78712
| | - Luke S. Browning
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Amanda L. Bohanon
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Eta A. Isiorho
- Macromolecular Crystallization Facility CUNY Advanced Science Research Center, New York, NY10031
| | - Kevin N. Dalby
- Division of Chemical Biology and Medicinal Chemistry, the University of Texas, Austin, TX78712
- Interdisciplinary Life Sciences Graduate Program, the University of Texas, Austin, TX78712
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY10031
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY10016
- PhD Program in Chemistry, The Graduate Center of CUNY, New York, NY10016
- PhD Program in Physics, The Graduate Center of CUNY, New York, NY10016
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3
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Aydemir E, Tüysüz EC, Bayrak ÖF, Tecimel D, Hızlı-Deniz AA, Şahin F. Impact of silencing eEF2K expression on the malignant properties of chordoma. Mol Biol Rep 2023; 50:3011-3022. [PMID: 36652154 DOI: 10.1007/s11033-023-08257-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 01/06/2023] [Indexed: 01/19/2023]
Abstract
BACKGROUND Eukaryotic elongation factor 2 kinase (eukaryotic elongation factor 2 kinase, eEF2K) is a calcium calmodulin dependent protein kinase that keeps the highest energy consuming cellular process of protein synthesis under check through negative regulation. eEF2K pauses global protein synthesis rates at the translational elongation step by phosphorylating its only kown substrate elongation factor 2 (eEF2), a unique translocase activity in ekaryotic cells enabling the polypeptide chain elongation. Therefore, eEF2K is thought to preserve cellular energy pools particularly upon acute development of cellular stress conditions such as nutrient deprivation, hypoxia, or infections. Recently, high expression of this enzyme has been associated with poor prognosis in an array of solid tumor types. Therefore, in a growing number of studies tremendous effort is being directed to the development of treatment methods aiming to suppress eEF2K as a novel therapeutic approach in the fight against cancer. METHODS In our study, we aimed to investigate the changes in the tumorigenicity of chordoma cells in presence of gene silencing for eEF2K. Taking a transient gene silencing approach using siRNA particles, eEF2K gene expression was suppressed in chordoma cells. RESULTS Silencing eEF2K expression was associated with a slight increase in cellular proliferation and a decrease in death rates. Furthermore, no alteration in the sensitivity of chordoma cells to chemotherapy was detected in response to the decrease in eEF2K expression which intriguingly promoted suppression of cell migratory and invasion related properties. CONCLUSION Our findings indicate that the loss of eEF2K expression in chordoma cell lines results in the reduction of metastatic capacity.
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Affiliation(s)
- Esra Aydemir
- Department of Biomedical Engineering, Faculty of Engineering and Natural Sciences, Biruni University, 10. Yil Cad, Protokol Yolu, No: 45 Topkapı, 34010, Istanbul, Turkey.
| | - Emre Can Tüysüz
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey.,Department of Medical Genetics, Yeditepe University Medical School and Yeditepe University Hospital, Istanbul, Turkey.,Department of Translational Medicine, Lund University, Malmö, Sweden
| | - Ömer Faruk Bayrak
- Department of Medical Genetics, Yeditepe University Medical School and Yeditepe University Hospital, Istanbul, Turkey
| | - Didem Tecimel
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey.,Department of Medical Genetics, Yeditepe University Medical School and Yeditepe University Hospital, Istanbul, Turkey
| | - Ayşen Aslı Hızlı-Deniz
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
| | - Fikrettin Şahin
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
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4
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Zhang J, Zhang L, Wang J, Ouyang L, Wang Y. Polo-like Kinase 1 Inhibitors in Human Cancer Therapy: Development and Therapeutic Potential. J Med Chem 2022; 65:10133-10160. [PMID: 35878418 DOI: 10.1021/acs.jmedchem.2c00614] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Polo-like kinase 1 (PLK1) plays an important role in a variety of cellular functions, including the regulation of mitosis, DNA replication, autophagy, and the epithelial-mesenchymal transition (EMT). PLK1 overexpression is often associated with cell proliferation and poor prognosis in cancer patients, making it a promising antitumor target. To date, at least 10 PLK1 inhibitors (PLK1i) have been entered into clinical trials, among which the typical kinase domain (KD) inhibitor BI 6727 (volasertib) was granted "breakthrough therapy designation" by the FDA in 2013. Unfortunately, many other KD inhibitors showed poor specificity, resulting in dose-limiting toxicity, which has greatly impeded their development. Researchers recently discovered many PLK1i with higher selectivity, stronger potency, and better absorption, distribution, metabolism, and elimination (ADME) characteristics. In this review, we emphasize the structure-activity relationships (SARs) of PLK1i, providing insights into new drugs targeting PLK1 for antitumor clinical practice.
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Affiliation(s)
- Jifa Zhang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China.,State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Lele Zhang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China.,State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Jiaxing Wang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis 38163, Tennessee, United States
| | - Liang Ouyang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China.,State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yuxi Wang
- Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, Joint Research Institution of Altitude Health, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China.,State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
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5
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Zhdanov AV, Golubeva AV, Yordanova MM, Andreev DE, Ventura-Silva AP, Schellekens H, Baranov PV, Cryan JF, Papkovsky DB. Ghrelin rapidly elevates protein synthesis in vitro by employing the rpS6K-eEF2K-eEF2 signalling axis. Cell Mol Life Sci 2022; 79:426. [PMID: 35841486 PMCID: PMC9288388 DOI: 10.1007/s00018-022-04446-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 06/16/2022] [Accepted: 06/22/2022] [Indexed: 11/27/2022]
Abstract
Activated ghrelin receptor GHS-R1α triggers cell signalling pathways that modulate energy homeostasis and biosynthetic processes. However, the effects of ghrelin on mRNA translation are unknown. Using various reporter assays, here we demonstrate a rapid elevation of protein synthesis in cells within 15–30 min upon stimulation of GHS-R1α by ghrelin. We further show that ghrelin-induced activation of translation is mediated, at least in part, through the de-phosphorylation (de-suppression) of elongation factor 2 (eEF2). The levels of eEF2 phosphorylation at Thr56 decrease due to the reduced activity of eEF2 kinase, which is inhibited via Ser366 phosphorylation by rpS6 kinases. Being stress-susceptible, the ghrelin-mediated decrease in eEF2 phosphorylation can be abolished by glucose deprivation and mitochondrial uncoupling. We believe that the observed burst of translation benefits rapid restocking of neuropeptides, which are released upon GHS-R1α activation, and represents the most time- and energy-efficient way of prompt recharging the orexigenic neuronal circuitry.
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Affiliation(s)
- Alexander V Zhdanov
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
| | - Anna V Golubeva
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland
| | - Martina M Yordanova
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - Dmitry E Andreev
- Belozersky Research Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.,Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, Moscow, Russia
| | - Ana Paula Ventura-Silva
- APC Microbiome Institute, University College Cork, Cork, Ireland.,School of Biomolecular and Biomedical Science, University College Dublin, Dublin 4, Ireland
| | - Harriet Schellekens
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Pavel V Baranov
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - John F Cryan
- Department of Anatomy & Neuroscience, University College Cork, Cork, Ireland.,APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Dmitri B Papkovsky
- School of Biochemistry & Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
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6
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Piserchio A, Isiorho EA, Long K, Bohanon AL, Kumar EA, Will N, Jeruzalmi D, Dalby KN, Ghose R. Structural basis for the calmodulin-mediated activation of eukaryotic elongation factor 2 kinase. SCIENCE ADVANCES 2022; 8:eabo2039. [PMID: 35857468 PMCID: PMC9258954 DOI: 10.1126/sciadv.abo2039] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 05/20/2022] [Indexed: 05/27/2023]
Abstract
Translation is a tightly regulated process that ensures optimal protein quality and enables adaptation to energy/nutrient availability. The α-kinase eukaryotic elongation factor 2 kinase (eEF-2K), a key regulator of translation, specifically phosphorylates the guanosine triphosphatase eEF-2, thereby reducing its affinity for the ribosome and suppressing the elongation phase of protein synthesis. eEF-2K activation requires calmodulin binding and autophosphorylation at the primary stimulatory site, T348. Biochemical studies predict a calmodulin-mediated activation mechanism for eEF-2K distinct from other calmodulin-dependent kinases. Here, we resolve the atomic details of this mechanism through a 2.3-Å crystal structure of the heterodimeric complex of calmodulin and the functional core of eEF-2K (eEF-2KTR). This structure, which represents the activated T348-phosphorylated state of eEF-2KTR, highlights an intimate association of the kinase with the calmodulin C-lobe, creating an "activation spine" that connects its amino-terminal calmodulin-targeting motif to its active site through a conserved regulatory element.
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Affiliation(s)
- Andrea Piserchio
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
| | - Eta A. Isiorho
- Macromolecular Crystallization Facility, CUNY ASRC, New York, NY 10031, USA
| | - Kimberly Long
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Amanda L. Bohanon
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Eric A. Kumar
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Nathan Will
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - David Jeruzalmi
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
| | - Kevin N. Dalby
- Division of Chemical Biology and Medicinal Chemistry, University of Texas, Austin, TX 78712, USA
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, USA
- PhD Program in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, USA
- PhD Program in Chemistry, The Graduate Center of CUNY, New York, NY 10016, USA
- PhD Program in Physics, The Graduate Center of CUNY, New York, NY 10016, USA
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7
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Wang X, Liu X, Yang Y, Yang D. Cyclin D1 mediated by the nuclear translocation of nuclear factor kappa B exerts an oncogenic role in lung cancer. Bioengineered 2022; 13:6866-6879. [PMID: 35246017 PMCID: PMC8974107 DOI: 10.1080/21655979.2022.2043099] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The relevance of cyclin D1 (CCND1) has been implicated in lung cancer progression. Nevertheless, the mechanism by which CCND1 supports lung cancer development is yet to be expounded. Here, we established that CCND1 is overexpressed in clinical lung cancer specimens and various lung cancer cells. Importantly, CCND1 overexpression enhanced lung cancer cell proliferation, invasion and migration, and arrested the cell cycle at the S phase. In vivo, overexpression of CCND1 promoted lung cancer growth and metastasis. The nuclear translocation of nuclear factor kappa B (NF-κB) promoted p65 protein expression and CCND1 transcription. Meanwhile, PI3K/AKT pathway activity was significantly reduced when NF-κB nuclear translocation was decreased. PI3K/AKT pathway activity was significantly elevated upon CCND1 overexpression. Inhibition of PI3K/AKT pathway activity or suppression of NF-κB translocation in cells with high CCND1 expression was found to significantly reduce the activity of lung cancer cells in vitro and in vivo. Our data revealed that NF-κB/CCND1/PI3K/AKT axis could act as a prospective diagnostic biomarker and a therapeutic option for lung cancer.
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Affiliation(s)
- Xin Wang
- Department of Respiratory and Critical Care Medicine, Second People's Hospital of Gansu Province & Northwest University for Nationality, Lanzhou, Gansu, China
| | - Xiaoping Liu
- Department of Respiratory and Critical Care Medicine, Second People's Hospital of Gansu Province & Northwest University for Nationality, Lanzhou, Gansu, China
| | - Yanxia Yang
- Department of Respiratory and Critical Care Medicine, Second People's Hospital of Gansu Province & Northwest University for Nationality, Lanzhou, Gansu, China
| | - Daowen Yang
- Department 1 of Lung Disease of TCM, China-Japan Friendship Hospital, Beijing, Chaoyang, China
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8
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Xu B, Liu L, Song G. Functions and Regulation of Translation Elongation Factors. Front Mol Biosci 2022; 8:816398. [PMID: 35127825 PMCID: PMC8807479 DOI: 10.3389/fmolb.2021.816398] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 12/20/2021] [Indexed: 12/18/2022] Open
Abstract
Translation elongation is a key step of protein synthesis, during which the nascent polypeptide chain extends by one amino acid residue during one elongation cycle. More and more data revealed that the elongation is a key regulatory node for translational control in health and disease. During elongation, elongation factor Tu (EF-Tu, eEF1A in eukaryotes) is used to deliver aminoacyl-tRNA (aa-tRNA) to the A-site of the ribosome, and elongation factor G (EF-G, EF2 in eukaryotes and archaea) is used to facilitate the translocation of the tRNA2-mRNA complex on the ribosome. Other elongation factors, such as EF-Ts/eEF1B, EF-P/eIF5A, EF4, eEF3, SelB/EFsec, TetO/Tet(M), RelA and BipA, have been found to affect the overall rate of elongation. Here, we made a systematic review on the canonical and non-canonical functions and regulation of these elongation factors. In particular, we discussed the close link between translational factors and human diseases, and clarified how post-translational modifications control the activity of translational factors in tumors.
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Affiliation(s)
- Benjin Xu
- Department of Medical Laboratory Science, Fenyang College, Shanxi Medical University, Fenyang, China
- *Correspondence: Benjin Xu, ; Guangtao Song,
| | - Ling Liu
- Department of Medical Laboratory Science, Fenyang College, Shanxi Medical University, Fenyang, China
| | - Guangtao Song
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
- *Correspondence: Benjin Xu, ; Guangtao Song,
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9
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Fernando S, Salagaras T, Schwarz N, Sandeman L, Tan JTM, Xie J, Zareh J, Jensen K, Williamson A, Dimasi C, Chhay P, Toledo-Flores D, Long A, Manavis J, Worthington M, Fitridge R, Di Bartolo BA, Bursill CA, Nicholls SJ, Proud CG, Psaltis PJ. Eukaryotic elongation factor 2 kinase regulates foam cell formation via translation of CD36. FASEB J 2022; 36:e22154. [PMID: 35032419 DOI: 10.1096/fj.202101034r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 12/14/2021] [Accepted: 12/27/2021] [Indexed: 11/11/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K) is an atypical protein kinase that controls protein synthesis in cells under stress. Although well studied in cancer, less is known about its roles in chronic inflammatory diseases. Here, we examined its regulation of macrophage cholesterol handling in the context of atherosclerosis. eEF2K mRNA expression and protein activity were upregulated in murine bone marrow-derived macrophages (BMDMs) exposed to oxidized low-density lipoprotein cholesterol (oxLDL). When incubated with oxLDL, BMDMs from eEF2K knockout (Eef2k-/- ) mice formed fewer Oil Red O+ foam cells than Eef2k+/+ BMDMs (12.5% ± 2.3% vs. 32.3% ± 2.0%, p < .01). Treatment with a selective eEF2K inhibitor, JAN-384, also decreased foam cell formation for C57BL/6J BMDMs and human monocyte-derived macrophages. Disabling eEF2K selectively decreased protein expression of the CD36 cholesterol uptake receptor, mediated by a reduction in the proportion of translationally active Cd36 mRNA. Eef2k-/- mice bred onto the Ldlr-/- background developed aortic sinus atherosclerotic plaques that were 30% smaller than Eef2k+/+ -Ldlr-/- mice after 16 weeks of high cholesterol diet (p < .05). Although accompanied by a reduction in plaque CD36+ staining (p < .05) and lower CD36 expression in circulating monocytes (p < .01), this was not associated with reduced lipid content in plaques as measured by oil red O staining. Finally, EEF2K and CD36 mRNA levels were higher in blood mononuclear cells from patients with coronary artery disease and recent myocardial infarction compared to healthy controls without coronary artery disease. These results reveal a new role for eEF2K in translationally regulating CD36 expression and foam cell formation in macrophages. Further studies are required to explore therapeutic targeting of eEF2K in atherosclerosis.
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Affiliation(s)
- Sanuja Fernando
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Thalia Salagaras
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Nisha Schwarz
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Lauren Sandeman
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Joanne T M Tan
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Jianling Xie
- Lifelong Health in Nutrition and Metabolism, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Jonar Zareh
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Kirk Jensen
- Lifelong Health in Nutrition and Metabolism, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Anna Williamson
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Catherine Dimasi
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Pich Chhay
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Deborah Toledo-Flores
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Aaron Long
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Jim Manavis
- Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Michael Worthington
- Department of Cardiothoracic Surgery, Royal Adelaide Hospital, Central Adelaide Local Health Network, Adelaide, South Australia, Australia
| | - Robert Fitridge
- Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia.,Department of Vascular Surgery, Royal Adelaide Hospital, Central Adelaide Local Health Network, Adelaide, South Australia, Australia
| | - Belinda A Di Bartolo
- The Kolling Institute, The University of Sydney, Sydney, New South Wales, Australia
| | - Christina A Bursill
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Stephen J Nicholls
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Monash Cardiovascular Research Centre, Monash University, Melbourne, Victoria, Australia
| | - Christopher G Proud
- Lifelong Health in Nutrition and Metabolism, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Peter J Psaltis
- Vascular Research Centre, Heart and Vascular Program, Lifelong Health Theme, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.,Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia.,Department of Cardiology, Royal Adelaide Hospital, Central Adelaide Local Health Network, Adelaide, South Australia, Australia
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10
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Ballard DJ, Peng HY, Das JK, Kumar A, Wang L, Ren Y, Xiong X, Ren X, Yang JM, Song J. Insights Into the Pathologic Roles and Regulation of Eukaryotic Elongation Factor-2 Kinase. Front Mol Biosci 2021; 8:727863. [PMID: 34532346 PMCID: PMC8438118 DOI: 10.3389/fmolb.2021.727863] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Accepted: 08/16/2021] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic Elongation Factor-2 Kinase (eEF2K) acts as a negative regulator of protein synthesis, translation, and cell growth. As a structurally unique member of the alpha-kinase family, eEF2K is essential to cell survival under stressful conditions, as it contributes to both cell viability and proliferation. Known as the modulator of the global rate of protein translation, eEF2K inhibits eEF2 (eukaryotic Elongation Factor 2) and decreases translation elongation when active. eEF2K is regulated by various mechanisms, including phosphorylation through residues and autophosphorylation. Specifically, this protein kinase is downregulated through the phosphorylation of multiple sites via mTOR signaling and upregulated via the AMPK pathway. eEF2K plays important roles in numerous biological systems, including neurology, cardiology, myology, and immunology. This review provides further insights into the current roles of eEF2K and its potential to be explored as a therapeutic target for drug development.
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Affiliation(s)
- Darby J. Ballard
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Hao-Yun Peng
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Jugal Kishore Das
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Anil Kumar
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Liqing Wang
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Yijie Ren
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Xiaofang Xiong
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
| | - Xingcong Ren
- Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Jin-Ming Yang
- Department of Toxicology and Cancer Biology, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Jianxun Song
- Department of Microbial Pathogenesis and Immunology, Texas A&M University Health Science Center, Bryan, TX, United States
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11
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Jiang M, Qi L, Jin K, Li L, Wu Y, Song D, Gan J, Huang M, Li Y, Song C. eEF2K as a novel metastatic and prognostic biomarker in gastric cancer patients. Pathol Res Pract 2021; 225:153568. [PMID: 34352439 DOI: 10.1016/j.prp.2021.153568] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/25/2021] [Accepted: 07/26/2021] [Indexed: 01/09/2023]
Abstract
BACKGROUND Although eukaryotic elongation factor 2 kinase (eEF2K) has been reported to be a potential oncogenic factor in many human cancers, its usefulness as a clinical prognostic biomarker for gastric cancer has not been investigated. METHODS In this study, data about 540 patients with stomach adenocarcinoma (STAD) were analyzed from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases to determine the expression of eEF2K. Immunohistochemistry (IHC), western blots, and real-time polymerase chain reaction (RT-PCR) were also performed to determine the clinical significance of eEF2K expression in 96 postoperative patients with gastric cancer. Among the 96 patients, 36 had low expression of eEF2K and 60 had high expression. RESULTS Analysis of the TCGA and GEO datasets revealed that eEF2K expression was significantly higher in the STAD tissue samples than in the non-tumorous gastric tissues. IHC, western blots, and RT-PCR confirmed these findings. The high expression level of eEF2K was found to be related to the presence of lymph node metastasis (p = 0.002). Moreover, multivariate analysis showed that eEF2K was an independent indicator of prognosis for overall survival (OS) (hazard ratio [HR] = 1.72, 95% confidence interval [CI] = 1.06-2.79; p = 0.03) and disease-free survival (DFS) (HR = 1.66, 95% CI = 0.997-2.765; p = 0.052) in patients with surgically resected STAD. CONCLUSION Collectively, our findings suggest that eEF2K is a clinical indicator of metastatic and prognostic significance for STAD survival and could serve as a potential therapeutic target.
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Affiliation(s)
- Mingxia Jiang
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Ling Qi
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Kexin Jin
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Lisha Li
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Yiming Wu
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Dongfeng Song
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Junqing Gan
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Mei Huang
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Yanjing Li
- Department of Gastrointestinal Oncology, Harbin Medical University Cancer Hospital, 150 Haping St, Nangang District, Harbin, Heilongjiang 150081, PR China.
| | - Chengxin Song
- Department of Colorectal Surgery, Harbin Medical University Cancer Hospital, Harbin 150081, China.
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12
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Meng F, Han X, Min Z, He X, Zhu S. Prognostic signatures associated with high infiltration of Tregs in bone metastatic prostate cancer. Aging (Albany NY) 2021; 13:17442-17461. [PMID: 34229299 PMCID: PMC8312432 DOI: 10.18632/aging.203234] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 06/12/2021] [Indexed: 02/06/2023]
Abstract
Metastatic cancer especially bone metastasis (BM) is the lethal end-stage of castration-resistant prostate cancer (CRPC). To understand the possible molecular mechanisms underlying the development of the distant metastasis is of potential clinical value. We sought to identify differentially expressed genes between patient-matched primary and bone metastatic CRPC tumors. Functional enrichment, protein-protein interaction networks, and survival analysis of DEGs were performed. DEGs with a prognostic value considered as candidate genes were evaluated, followed by genetic analysis of tumor infiltrating immune cells based on Wilcoxon test and immunofluorescence identification. Expression profiles analysis showed that 381 overlapping genes were screened as differentially expressed genes (DEGs), of which 16 DEGs were randomly selected to be validated and revealed that most of these genes showed a transcriptional profile similar to that seen in the datasets (Pearson’s r = 0.76). Six core genes were found to be involved in regulation of extracellular matrix receptor interaction and chemotactic activity, and four of them were significantly correlated with the survival of PCa patients with bone metastases. Immune infiltration analysis showed that the expressions levels of COL3A1, RAC1, FN1, and SDC2 in CD4+T cells were significantly higher than those in tumor cells, especially regulatory T cell infiltration was significantly increased in BM tumors. We analyzed gene expression signatures specifically associated with the development of bone metastases of CRPC patients. Characterization of genes associated with BM of mCRPC is critical for identification of predictive biomarkers and potential therapeutic targets.
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Affiliation(s)
- Fanjing Meng
- Key Laboratory of Tumor Immunity, Department of Immunology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Xu Han
- Key Laboratory of Tumor Immunity, Department of Immunology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Zhixue Min
- Department of Pathology, The Third People's Hospital of Zhengzhou, Zhengzhou, China
| | - Xuehui He
- Key Laboratory of Tumor Immunity, Department of Immunology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Sha Zhu
- Key Laboratory of Tumor Immunity, Department of Immunology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
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13
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Alboushi L, Hackett AP, Naeli P, Bakhti M, Jafarnejad SM. Multifaceted control of mRNA translation machinery in cancer. Cell Signal 2021; 84:110037. [PMID: 33975011 DOI: 10.1016/j.cellsig.2021.110037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 05/06/2021] [Indexed: 12/15/2022]
Abstract
The mRNA translation machinery is tightly regulated through several, at times overlapping, mechanisms that modulate its efficiency and accuracy. Due to their fast rate of growth and metabolism, cancer cells require an excessive amount of mRNA translation and protein synthesis. However, unfavorable conditions, such as hypoxia, amino acid starvation, and oxidative stress, which are abundant in cancer, as well as many anti-cancer treatments inhibit mRNA translation. Cancer cells adapt to the various internal and environmental stresses by employing specialised transcript-specific translation to survive and gain a proliferative advantage. We will highlight the major signaling pathways and mechanisms of translation that regulate the global or mRNA-specific translation in response to the intra- or extra-cellular signals and stresses that are key components in the process of tumourigenesis.
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Affiliation(s)
- Lilas Alboushi
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Angela P Hackett
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Parisa Naeli
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
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14
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Ju Y, Ben-David Y, Rotin D, Zacksenhaus E. Inhibition of eEF2K synergizes with glutaminase inhibitors or 4EBP1 depletion to suppress growth of triple-negative breast cancer cells. Sci Rep 2021; 11:9181. [PMID: 33911160 PMCID: PMC8080725 DOI: 10.1038/s41598-021-88816-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 04/16/2021] [Indexed: 12/13/2022] Open
Abstract
The eukaryotic elongation factor-2 kinase, eEF2K, which restricts protein translation elongation, has been identified as a potential therapeutic target for diverse types of malignancies including triple negative breast cancer (TNBC). However, the contexts in which eEF2K inhibition is essential in TNBC and its consequences on the proteome are largely unknown. Here we show that genetic or pharmacological inhibition of eEF2K cooperated with glutamine (Gln) starvation, and synergized with glutaminase (GLS1) inhibitors to suppress growth of diverse TNBC cell lines. eEF2K inhibition also synergized with depletion of eukaryotic translation initiation factor 4E-binding protein 1 (eIF4EBP1; 4EBP1), a suppressor of eukaryotic protein translation initiation factor 4E (eIF4E), to induce c-MYC and Cyclin D1 expression, yet attenuate growth of TNBC cells. Proteomic analysis revealed that whereas eEF2K depletion alone uniquely induced Cyclin Dependent Kinase 1 (CDK1) and 6 (CDK6), combined depletion of eEF2K and 4EBP1 resulted in overlapping effects on the proteome, with the highest impact on the 'Collagen containing extracellular matrix' pathway (e.g. COL1A1), as well as the amino-acid transporter, SLC7A5/LAT1, suggesting a regulatory loop via mTORC1. In addition, combined depletion of eEF2K and 4EBP1 indirectly reduced the levels of IFN-dependent innate immune response-related factors. Thus, eEF2K inhibition triggers cell cycle arrest/death under unfavourable metabolic conditions such as Gln-starvation/GLS1 inhibition or 4EBP1 depletion, uncovering new therapeutic avenues for TNBC and underscoring a pressing need for clinically relevant eEF2K inhibitors.
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Affiliation(s)
- YoungJun Ju
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, 101 College Street, Suite 5R406, Toronto, ON, M5G 1L7, Canada
| | - Yaacov Ben-David
- The Key Laboratory of Chemistry for Natural Products of Guizhou Province, Chinese Academic of Sciences, Guiyang, 550014, Guizhou, China
- State Key Laboratory for Functions and Applications of Medicinal Plants, Guizhou Medical University, Guiyang, 550025, China
| | - Daniela Rotin
- Program in Cell Biology, The Peter Gilgan Center for Research and Learning, The Hospital for Sick Children, Toronto, ON, Canada
| | - Eldad Zacksenhaus
- Max Bell Research Centre, Toronto General Research Institute, University Health Network, 101 College Street, Suite 5R406, Toronto, ON, M5G 1L7, Canada.
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15
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Xie J, De Poi SP, Humphrey SJ, Hein LK, Bruning JB, Pan W, Selth LA, Sargeant TJ, Proud CG. TSC-insensitive Rheb mutations induce oncogenic transformation through a combination of constitutively active mTORC1 signalling and proteome remodelling. Cell Mol Life Sci 2021; 78:4035-4052. [PMID: 33834258 PMCID: PMC11072378 DOI: 10.1007/s00018-021-03825-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 02/02/2021] [Accepted: 03/27/2021] [Indexed: 01/18/2023]
Abstract
The mechanistic target of rapamycin complex 1 (mTORC1) is an important regulator of cellular metabolism that is commonly hyperactivated in cancer. Recent cancer genome screens have identified multiple mutations in Ras-homolog enriched in brain (Rheb), the primary activator of mTORC1 that might act as driver oncogenes by causing hyperactivation of mTORC1. Here, we show that a number of recurrently occurring Rheb mutants drive hyperactive mTORC1 signalling through differing levels of insensitivity to the primary inactivator of Rheb, tuberous sclerosis complex. We show that two activated mutants, Rheb-T23M and E40K, strongly drive increased cell growth, proliferation and anchorage-independent growth resulting in enhanced tumour growth in vivo. Proteomic analysis of cells expressing the mutations revealed, surprisingly, that these two mutants promote distinct oncogenic pathways with Rheb-T23M driving an increased rate of anaerobic glycolysis, while Rheb-E40K regulates the translation factor eEF2 and autophagy, likely through differential interactions with 5' AMP-activated protein kinase (AMPK) which modulate its activity. Our findings suggest that unique, personalized, combination therapies may be utilised to treat cancers according to which Rheb mutant they harbour.
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Affiliation(s)
- Jianling Xie
- Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, 5001, Australia
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK
| | - Stuart P De Poi
- Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, 5001, Australia
- Department of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Sean J Humphrey
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, 2006, Australia
| | - Leanne K Hein
- Lysosomal Health in Ageing, Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, 5001, Australia
| | - John B Bruning
- Institute for Photonics and Advanced Sensing, School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Wenru Pan
- Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, 5001, Australia
- Adelaide Medical School, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Luke A Selth
- Flinders Health and Medical Research Institute, Flinders University, Bedford Park, SA, 5042, Australia
| | - Timothy J Sargeant
- Lysosomal Health in Ageing, Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, 5001, Australia
| | - Christopher G Proud
- Lifelong Health, South Australian Health and Medical Research Institute, Adelaide, SA, 5001, Australia.
- School of Biological Sciences, University of Southampton, Southampton, SO17 1BJ, UK.
- Department of Molecular and Biomedical Sciences, University of Adelaide, Adelaide, SA, 5005, Australia.
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16
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eEF2K enhances expression of PD-L1 by promoting the translation of its mRNA. Biochem J 2021; 477:4367-4381. [PMID: 33094805 DOI: 10.1042/bcj20200697] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 12/22/2022]
Abstract
Emerging advances in cancer therapy have transformed the landscape towards cancer immunotherapy regimens. Recent discoveries have resulted in the development of clinical immune checkpoint inhibitors that are 'game-changers' for cancer immunotherapy. Here we show that eEF2K, an atypical protein kinase that negatively modulates the elongation stage of protein synthesis, promotes the synthesis of PD-L1, an immune checkpoint protein which helps cancer cells to escape from immunosurveillance. Ablation of eEF2K in prostate and lung cancer cells markedly reduced the expression levels of the PD-L1 protein. We show that eEF2K promotes the association of PD-L1 mRNAs with translationally active polyribosomes and that translation of the PD-L1 mRNA is regulated by a uORF (upstream open reading-frame) within its 5'-UTR (5'-untranslated region) which starts with a non-canonical CUG as the initiation codon. This inhibitory effect is attenuated by eEF2K thereby allowing higher levels of translation of the PD-L1 coding region and enhanced expression of the PD-L1 protein. Moreover, eEF2K-depleted cancer cells are more vulnerable to immune attack by natural killer cells. Therefore, control of translation elongation can modulate the translation of this specific mRNA, one which contains an uORF that starts with CUG, and perhaps others that contain a similar feature. Taken together, our data reveal that eEF2K regulates PD-L1 expression at the level of the translation of its mRNA by virtue of a uORF in its 5'-region. This, and other roles of eEF2K in cancer cell biology (e.g. in cell survival and migration), may be exploited for the design of future therapeutic strategies.
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17
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Progress in the Development of Eukaryotic Elongation Factor 2 Kinase (eEF2K) Natural Product and Synthetic Small Molecule Inhibitors for Cancer Chemotherapy. Int J Mol Sci 2021; 22:ijms22052408. [PMID: 33673713 PMCID: PMC7957638 DOI: 10.3390/ijms22052408] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 12/12/2022] Open
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K or Ca2+/calmodulin-dependent protein kinase, CAMKIII) is a new member of an atypical α-kinase family different from conventional protein kinases that is now considered as a potential target for the treatment of cancer. This protein regulates the phosphorylation of eukaryotic elongation factor 2 (eEF2) to restrain activity and inhibit the elongation stage of protein synthesis. Mounting evidence shows that eEF2K regulates the cell cycle, autophagy, apoptosis, angiogenesis, invasion, and metastasis in several types of cancers. The expression of eEF2K promotes survival of cancer cells, and the level of this protein is increased in many cancer cells to adapt them to the microenvironment conditions including hypoxia, nutrient depletion, and acidosis. The physiological function of eEF2K and its role in the development and progression of cancer are here reviewed in detail. In addition, a summary of progress for in vitro eEF2K inhibitors from anti-cancer drug discovery research in recent years, along with their structure-activity relationships (SARs) and synthetic routes or natural sources, is also described. Special attention is given to those inhibitors that have been already validated in vivo, with the overall aim to provide reference context for the further development of new first-in-class anti-cancer drugs that target eEF2K.
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18
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Chen MF. The role of calmodulin and calmodulin-dependent protein kinases in the pathogenesis of atherosclerosis. Tzu Chi Med J 2021; 34:160-168. [PMID: 35465283 PMCID: PMC9020235 DOI: 10.4103/tcmj.tcmj_119_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 05/31/2021] [Accepted: 06/29/2021] [Indexed: 12/02/2022] Open
Abstract
Atherosclerosis is a chronic inflammatory disease that triggers severe thrombotic cardiovascular events, such as stroke and myocardial infarction. In atherosclerotic processes, both macrophages and vascular smooth muscle cells (VSMCs) are essential cell components in atheromata formation through proinflammatory cytokine secretion, defective efferocytosis, cell migration, and proliferation, primarily controlled by Ca2+-dependent signaling. Calmodulin (CaM), as a versatile Ca2+ sensor in diverse cell types, regulates a broad spectrum of Ca2+-dependent cell functions through the actions of downstream protein kinases. Thus, this review focuses on discussing how CaM and CaM-dependent kinases (CaMKs) regulate the functions of macrophages and VSMCs in atherosclerotic plaque development based on literature from open databases. A central theme in this review is a summary of the mechanisms and consequences underlying CaMK-mediated macrophage inflammation and apoptosis, which are the key processes in necrotic core formation in atherosclerosis. Another central theme is addressing the role of CaM and CaMK-dependent pathways in phenotypic modulation, migration, and proliferation of VSMCs in atherosclerotic progression. A complete understanding of CaM and CaMK-controlled individual processes involving macrophages and VSMCs in atherogenesis might provide helpful information for developing potential therapeutic targets and strategies.
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19
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Dysregulation of TCTP in Biological Processes and Diseases. Cells 2020; 9:cells9071632. [PMID: 32645936 PMCID: PMC7407922 DOI: 10.3390/cells9071632] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/02/2020] [Accepted: 07/03/2020] [Indexed: 12/12/2022] Open
Abstract
Translationally controlled tumor protein (TCTP), also called histamine releasing factor (HRF) or fortilin, is a multifunctional protein present in almost all eukaryotic organisms. TCTP is involved in a range of basic cell biological processes, such as promotion of growth and development, or cellular defense in response to biological stresses. Cellular TCTP levels are highly regulated in response to a variety of physiological signals, and regulatory mechanism at various levels have been elucidated. Given the importance of TCTP in maintaining cellular homeostasis, it is not surprising that dysregulation of this protein is associated with a range of disease processes. Here, we review recent progress that has been made in the characterisation of the basic biological functions of TCTP, in the description of mechanisms involved in regulating its cellular levels and in the understanding of dysregulation of TCTP, as it occurs in disease processes such as cancer.
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20
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Jin X, Xie J, Zabolocki M, Wang X, Jiang T, Wang D, Désaubry L, Bardy C, Proud CG. The prohibitin-binding compound fluorizoline affects multiple components of the translational machinery and inhibits protein synthesis. J Biol Chem 2020; 295:9855-9867. [PMID: 32430400 DOI: 10.1074/jbc.ra120.012979] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/12/2020] [Indexed: 01/12/2023] Open
Abstract
Fluorizoline (FLZ) binds to prohibitin-1 and -2 (PHB1/2), which are pleiotropic scaffold proteins known to affect signaling pathways involved in several intracellular processes. However, it is not yet clear how FLZ exerts its effect. Here, we show that exposure of three different human cancer cell lines to FLZ increases the phosphorylation of key translation factors, particularly of initiation factor 2 (eIF2) and elongation factor 2 (eEF2), modifications that inhibit their activities. FLZ also impaired signaling through mTOR complex 1, which also regulates the translational machinery, e.g. through the eIF4E-binding protein 4E-BP1. In line with these findings, FLZ potently inhibited protein synthesis. We noted that the first phase of this inhibition involves very rapid eEF2 phosphorylation, which is catalyzed by a dedicated Ca2+-dependent protein kinase, eEF2 kinase (eEF2K). We also demonstrate that FLZ induces a swift and marked rise in intracellular Ca2+ levels, likely explaining the effects on eEF2. Disruption of normal Ca2+ homeostasis can also induce endoplasmic reticulum stress, and our results suggest that induction of this stress response contributes to the increased phosphorylation of eIF2, likely because of activation of the eIF2-modifying kinase PKR-like endoplasmic reticulum kinase (PERK). We show that FLZ induces cancer cell death and that this effect involves contributions from the phosphorylation of both eEF2 and eIF2. Our findings provide important new insights into the biological effects of FLZ and thus the roles of PHBs, specifically in regulating Ca2+ levels, cellular protein synthesis, and cell survival.
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Affiliation(s)
- Xin Jin
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology and School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Jianling Xie
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Michael Zabolocki
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia.,Laboratory for Human Neurophysiology and Genetics, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Xuemin Wang
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia.,School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Tao Jiang
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology and School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Dong Wang
- Sino-French Joint Lab of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Laurent Désaubry
- Sino-French Joint Lab of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,Laboratory of Medicinal Chemistry and Cardio-oncology, CNRS, Strasbourg, France
| | - Cedric Bardy
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia.,Laboratory for Human Neurophysiology and Genetics, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Christopher G Proud
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia .,School of Biological Sciences, University of Adelaide, Adelaide, Australia
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21
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Karakas D, Ozpolat B. Eukaryotic elongation factor-2 kinase (eEF2K) signaling in tumor and microenvironment as a novel molecular target. J Mol Med (Berl) 2020; 98:775-787. [PMID: 32377852 DOI: 10.1007/s00109-020-01917-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 04/26/2020] [Accepted: 04/28/2020] [Indexed: 12/25/2022]
Abstract
Eukaryotic elongation factor-2 kinase (eEF2K), an atypical member of alpha-kinase family, is highly overexpressed in breast, pancreatic, brain, and lung cancers, and associated with poor survival in patients. eEF2K promotes cell proliferation, survival, and aggressive tumor characteristics, leading to tumor growth and progression. While initial studies indicated that eEF2K acts as a negative regulator of protein synthesis by suppressing peptide elongation phase, later studies demonstrated that it has multiple functions and promotes cell cycle, angiogenesis, migration, and invasion as well as induction of epithelial-mesenchymal transition through induction of integrin β1, SRC/FAK, PI3K/AKT, cyclin D1, VEGF, ZEB1, Snail, and MMP-2. Under stress conditions such as hypoxia and metabolic distress, eEF2K is activated by several signaling pathways and slows down protein synthesis and helping cells to save energy and survive. In vivo therapeutic targeting of eEF2K by genetic methods inhibits tumor growth in various tumor models, validating it as a potential molecular target. Recent studies suggest that eEF2K plays a role in tumor microenvironment cells by monocyte chemoattractant protein-1 (MCP-1) and accumulation of tumor-associated macrophages. Due to its clinical significance and the pivotal role in tumorigenesis and progression, eEF2K is considered as an important therapeutic target in solid tumors. However, currently, there is no specific and potent inhibitor for translation into clinical studies. Here, we aim to systematically review current knowledge regarding eEF2K in tumor biology, microenvironment, and development of eEF2K targeted inhibitors and therapeutics.
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Affiliation(s)
- Didem Karakas
- Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Istinye University, Istanbul, Turkey
| | - Bulent Ozpolat
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
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22
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Knight JRP, Garland G, Pöyry T, Mead E, Vlahov N, Sfakianos A, Grosso S, De-Lima-Hedayioglu F, Mallucci GR, von der Haar T, Smales CM, Sansom OJ, Willis AE. Control of translation elongation in health and disease. Dis Model Mech 2020; 13:dmm043208. [PMID: 32298235 PMCID: PMC7104864 DOI: 10.1242/dmm.043208] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Regulation of protein synthesis makes a major contribution to post-transcriptional control pathways. During disease, or under stress, cells initiate processes to reprogramme protein synthesis and thus orchestrate the appropriate cellular response. Recent data show that the elongation stage of protein synthesis is a key regulatory node for translational control in health and disease. There is a complex set of factors that individually affect the overall rate of elongation and, for the most part, these influence either transfer RNA (tRNA)- and eukaryotic elongation factor 1A (eEF1A)-dependent codon decoding, and/or elongation factor 2 (eEF2)-dependent ribosome translocation along the mRNA. Decoding speeds depend on the relative abundance of each tRNA, the cognate:near-cognate tRNA ratios and the degree of tRNA modification, whereas eEF2-dependent ribosome translocation is negatively regulated by phosphorylation on threonine-56 by eEF2 kinase. Additional factors that contribute to the control of the elongation rate include epigenetic modification of the mRNA, coding sequence variation and the expression of eIF5A, which stimulates peptide bond formation between proline residues. Importantly, dysregulation of elongation control is central to disease mechanisms in both tumorigenesis and neurodegeneration, making the individual key steps in this process attractive therapeutic targets. Here, we discuss the relative contribution of individual components of the translational apparatus (e.g. tRNAs, elongation factors and their modifiers) to the overall control of translation elongation and how their dysregulation contributes towards disease processes.
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Affiliation(s)
| | - Gavin Garland
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| | - Tuija Pöyry
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| | - Emma Mead
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Nikola Vlahov
- Beatson Institute for Cancer Research, Glasgow G61 1BD, UK
| | - Aristeidis Sfakianos
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| | - Stefano Grosso
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
| | | | - Giovanna R Mallucci
- UK Dementia Research Institute at the University of Cambridge and Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0XY, UK
| | | | - C Mark Smales
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Owen J Sansom
- Beatson Institute for Cancer Research, Glasgow G61 1BD, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, G61 1QH, UK
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Lancaster Road, Leicester LE1 9HN, UK
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23
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Xiao M, Xie J, Wu Y, Wang G, Qi X, Liu Z, Wang Y, Wang X, Hoque A, Oakhill J, Proud CG, Li J. The eEF2 kinase-induced STAT3 inactivation inhibits lung cancer cell proliferation by phosphorylation of PKM2. Cell Commun Signal 2020; 18:25. [PMID: 32054489 PMCID: PMC7020344 DOI: 10.1186/s12964-020-0528-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 02/05/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Eukaryotic elongation factor-2 kinase (eEF2K) is a Ca 2+ /calmodulin (CaM)-dependent protein kinase that inhibits protein synthesis. However, the role of eEF2K in cancer development was reported paradoxically and remains to be elucidated. METHODS Herein, A549 cells with eEF2K depletion or overexpression by stably transfected lentivirus plasmids were used in vitro and in vivo study. MTT and colony assays were used to detect cell proliferation and growth. Extracellular glucose and lactate concentration were measured using test kit. Immunoblot and co-immunoprecipitation assays were used to examine the molecular biology changes and molecular interaction in these cells. LC-MS/MS analysis and [γ- 32 P] ATP kinase assay were used to identify combining protein and phosphorylation site. Nude mice was utilized to study the correlation of eEF2K and tumor growth in vivo. RESULTS We demonstrated that eEF2K inhibited lung cancer cells proliferation and affected the inhibitory effects of EGFR inhibitor gefitinib. Mechanistically, we showed that eEF2K formed a complex with PKM2 and STAT3, thereby phosphorylated PKM2 at T129, leading to reduced dimerization of PKM2. Subsequently, PKM2 impeded STAT3 phosphorylation and STAT3-dependent c-Myc expression. eEF2K depletion promoted the nuclear translocation of PKM2 and increased aerobic glycolysis reflected by increased lactate secretion and glucose. CONCLUSIONS Our findings define a novel mechanism underlying the regulation of cancer cell proliferation by eEF2K independent of its role in protein synthesis, disclosing the diverse roles of eEF2K in cell biology, which lays foundation for the development of new anticancer therapeutic strategies.
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Affiliation(s)
- Min Xiao
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Jianling Xie
- South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
| | - Yu Wu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Genzhu Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Xin Qi
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Zailiang Liu
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Yuying Wang
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Xuemin Wang
- South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Ashfaqul Hoque
- St Vincent's Institute of Medical Research, Fitzroy, SA, 4312, Australia
| | - Jon Oakhill
- St Vincent's Institute of Medical Research, Fitzroy, SA, 4312, Australia
| | - Christopher G Proud
- South Australian Health & Medical Research Institute, North Terrace, Adelaide, SA, 5000, Australia
- School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Jing Li
- Key Laboratory of Marine Drugs, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, People's Republic of China.
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, People's Republic of China.
- Open Studio for Druggability Research of Marine Natural Products, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, People's Republic of China.
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24
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What is the impact of eukaryotic elongation factor 2 kinase on cancer: A systematic review. Eur J Pharmacol 2019; 857:172470. [DOI: 10.1016/j.ejphar.2019.172470] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Revised: 06/08/2019] [Accepted: 06/17/2019] [Indexed: 11/19/2022]
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25
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Zhou Y, Li Y, Xu S, Lu J, Zhu Z, Chen S, Tan Y, He P, Xu J, Proud CG, Xie J, Shen K. Eukaryotic elongation factor 2 kinase promotes angiogenesis in hepatocellular carcinoma via PI3K/Akt and STAT3. Int J Cancer 2019; 146:1383-1395. [PMID: 31286509 DOI: 10.1002/ijc.32560] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 05/31/2019] [Accepted: 06/25/2019] [Indexed: 12/23/2022]
Abstract
Hepatocellular carcinoma (HCC) is an aggressive malignancy with increasing mortality in China. Angiogenesis is crucial for tumor formation, development and metastasis in HCC. Previous studies indicated that high expression levels of elongation factor 2 kinase (eEF2K), a protein kinase that negatively regulates the elongation stage of translation, were associated with poor prognosis of HCC. Here, we show that pharmacological inhibition or knockdown of eEF2K in highly metastatic liver cancer cells inhibits their colony forming and migratory capacities, as well as reducing their invasiveness. Importantly, knocking down eEF2K by lentiviral directed shRNA prevented tumor growth and angiogenesis of HCC in mice. Silencing of eEF2K in endothelial cells (HUVECs) led to a reduction in vascularization, evidenced by a decrease in capillary-like structures in the matrigel. Notably, knocking down eEF2K reduced the expression of angiogenesis-related growth factors in liver cancer cells and the expression of growth factor receptors on HUVECs, and thus restricted signaling crosstalk that promotes angiogenesis between HCC cells and endothelial cells. We also showed that silencing of eEF2K effectively reduced protein levels of SP1/KLF5 transcription factors and hence decreased the levels of bound SP1/KLF5 to the VEGF promoter, resulted in a decrease in VEGF mRNA expression. Knocking down eEF2K also led to a striking decrease in the phosphorylation of PI3K/Akt and STAT3, indicating inactivation of these tumorigenic pathways. Taken together, our data suggest that eEF2K contributes to angiogenesis and tumor progression in HCC via SP1/KLF5-mediated VEGF expression, as well as the subsequent stimulation of PI3K/Akt and STAT3 signaling.
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Affiliation(s)
- Ying Zhou
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Laboratory of Drug Metabolism and Pharmaceutical Analysis, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yaoting Li
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Shihao Xu
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Jing Lu
- State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Ziyi Zhu
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Shaoli Chen
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yuan Tan
- Department of Integrated TCM & Western Medicine, Shanghai First Maternity and Infant Hospital, Tongji University, Shanghai, China
| | - Peng He
- Department of Nephrology, Huabeishiyou Hospital of Traditional Chinese Medicine, Hebei, China
| | - Jin Xu
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Christopher G Proud
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, South Australia, Australia.,School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Jianling Xie
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, South Australia, Australia
| | - Kaikai Shen
- School of Basic Medical Sciences, Shanghai University of Traditional Chinese Medicine, Shanghai, China.,Medical Research Council Toxicology Unit, University of Cambridge, Leicester, United Kingdom
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26
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Xie J, Van Damme P, Fang D, Proud CG. Ablation of elongation factor 2 kinase enhances heat-shock protein 90 chaperone expression and protects cells under proteotoxic stress. J Biol Chem 2019; 294:7169-7176. [PMID: 30890561 DOI: 10.1074/jbc.ac119.008036] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 03/14/2019] [Indexed: 12/27/2022] Open
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K) negatively regulates the elongation stage of mRNA translation and is activated under different stress conditions to slow down protein synthesis. One effect of eEF2K is to alter the repertoire of expressed proteins, perhaps to aid survival of stressed cells. Here, we applied pulsed stable isotope labeling with amino acids in cell culture (SILAC) to study changes in the synthesis of specific proteins in human lung adenocarcinoma (A549) cells in which eEF2K had been depleted by an inducible shRNA. We discovered that levels of heat-shock protein 90 (HSP90) are increased in eEF2K-depleted human cells as well as in eEF2K-knockout (eEF2K-/-) mouse embryonic fibroblasts (MEFs). This rise in HSP90 coincided with an increase in the fraction of HSP90 mRNAs associated with translationally active polysomes, irrespective of unchanged total HSP90 levels. These results indicate that blocking eEF2K function can enhance expression of HSP90 chaperones. In eEF2K-/- mouse embryonic fibroblasts (MEFs), inhibition of HSP90 by its specific inhibitor AUY922 promoted the accumulation of ubiquitinated proteins. Notably, HSP90 inhibition promoted apoptosis of eEF2K-/- MEFs under proteostatic stress induced by the proteasome inhibitor MG132. Up-regulation of HSP90 likely protects cells from protein folding stress, arising, for example, from faster rates of polypeptide synthesis due to the lack of eEF2K. Our findings indicate that eEF2K and HSPs closely cooperate to maintain proper proteostasis and suggest that concomitant inhibition of HSP90 and eEF2K could be a strategy to decrease cancer cell survival.
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Affiliation(s)
- Jianling Xie
- From the Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide SA5000, Australia
| | - Petra Van Damme
- Department of Biochemistry and Microbiology, Ghent University, B-9000 Ghent, Belgium.,VIB Center for Medical Biotechnology, Ghent, Belgium, and
| | - Danielle Fang
- From the Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide SA5000, Australia.,School of Biological Sciences, University of Adelaide, Adelaide SA5005, Australia
| | - Christopher G Proud
- From the Lifelong Health Theme, South Australian Health and Medical Research Institute, North Terrace, Adelaide SA5000, Australia, .,School of Biological Sciences, University of Adelaide, Adelaide SA5005, Australia
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27
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Xie J, de Souza Alves V, von der Haar T, O’Keefe L, Lenchine RV, Jensen KB, Liu R, Coldwell MJ, Wang X, Proud CG. Regulation of the Elongation Phase of Protein Synthesis Enhances Translation Accuracy and Modulates Lifespan. Curr Biol 2019; 29:737-749.e5. [DOI: 10.1016/j.cub.2019.01.029] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 12/12/2018] [Accepted: 01/11/2019] [Indexed: 02/07/2023]
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28
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Ediriweera MK, Tennekoon KH, Samarakoon SR. In vitro assays and techniques utilized in anticancer drug discovery. J Appl Toxicol 2018; 39:38-71. [DOI: 10.1002/jat.3658] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/01/2018] [Accepted: 06/04/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Meran Keshawa Ediriweera
- Institute of Biochemistry, Molecular Biology and Biotechnology; University of Colombo; Colombo 03 Sri Lanka
| | - Kamani Hemamala Tennekoon
- Institute of Biochemistry, Molecular Biology and Biotechnology; University of Colombo; Colombo 03 Sri Lanka
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