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Knutsen JHJ, Rødland GE, Bøe CA, Håland TW, Sunnerhagen P, Grallert B, Boye E. Stress-induced inhibition of translation independently of eIF2α phosphorylation. J Cell Sci 2015; 128:4420-7. [PMID: 26493332 PMCID: PMC4712817 DOI: 10.1242/jcs.176545] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 09/28/2015] [Indexed: 01/21/2023] Open
Abstract
Exposure of fission yeast cells to ultraviolet (UV) light leads to inhibition of translation and phosphorylation of the eukaryotic initiation factor-2α (eIF2α). This phosphorylation is a common response to stress in all eukaryotes. It leads to inhibition of translation at the initiation stage and is thought to be the main reason why stressed cells dramatically reduce protein synthesis. Phosphorylation of eIF2α has been taken as a readout for downregulation of translation, but the role of eIF2α phosphorylation in the downregulation of general translation has not been much investigated. We show here that UV-induced global inhibition of translation in fission yeast cells is independent of eIF2α phosphorylation and the eIF2α kinase general control nonderepressible-2 protein (Gcn2). Also, in budding yeast and mammalian cells, the UV-induced translational depression is largely independent of GCN2 and eIF2α phosphorylation. Furthermore, exposure of fission yeast cells to oxidative stress generated by hydrogen peroxide induced an inhibition of translation that is also independent of Gcn2 and of eIF2α phosphorylation. Our findings show that stress-induced translational inhibition occurs through an unknown mechanism that is likely to be conserved through evolution. Summary: In contrast to textbook knowledge, the phosphorylation of translation initiation factor eIF2α is not required for UV-induced inhibition of protein synthesis, which we show in three different cell types.
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Affiliation(s)
| | - Gro Elise Rødland
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Cathrine Arnason Bøe
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Tine Weise Håland
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Per Sunnerhagen
- Department of Chemistry & Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Beáta Grallert
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
| | - Erik Boye
- Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Oslo, Norway
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Direct and high throughput (HT) interactions on the ribosomal surface by iRIA. Sci Rep 2015; 5:15401. [PMID: 26486184 PMCID: PMC4613909 DOI: 10.1038/srep15401] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 09/21/2015] [Indexed: 02/04/2023] Open
Abstract
Ribosomes function as platforms for binding of other molecules, but technologies for studying this process are lacking. Therefore we developed iRIA (in vitro Ribosomes Interaction Assay). In approach I, Artemia salina ribosomes spotted on solid phase are used for binding picomoles of analytes; in approach II, cellular extracts allow the measurement of ribosome activity in different conditions. We apply the method to analyze several features of eIF6 binding to 60S subunits. By approach I, we show that the off-rate of eIF6 from preribosomes is slower than from mature ribosomes and that its binding to mature 60S occurs in the nM affinity range. By approach II we show that eIF6 binding sites on 60S are increased with mild eIF6 depletion and decreased in cells that are devoid of SBDS, a ribosomal factor necessary for 60S maturation and involved in Swachman Diamond syndrome. We show binding conditions to immobilized ribosomes adaptable to HT and quantify free ribosomes in cell extracts. In conclusion, we suggest that iRIA will greatly facilitate the study of interactions on the ribosomal surface.
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Barbieri M, Manzoni M, Fabris S, Ciceri G, Todoerti K, Simeon V, Musto P, Cortelezzi A, Baldini L, Neri A, Lionetti M. Compendium ofFAM46Cgene mutations in plasma cell dyscrasias. Br J Haematol 2015; 174:642-5. [DOI: 10.1111/bjh.13793] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Marzia Barbieri
- Haematology Unit; Fondazione IRCCS Ca’ Granda; Ospedale Maggiore Policlinico; Milan Italy
| | - Martina Manzoni
- Department of Clinical Sciences and Community Health; University of Milan; Milan Italy
| | - Sonia Fabris
- Haematology Unit; Fondazione IRCCS Ca’ Granda; Ospedale Maggiore Policlinico; Milan Italy
| | - Gabriella Ciceri
- Department of Clinical Sciences and Community Health; University of Milan; Milan Italy
| | - Katia Todoerti
- Laboratory of Pre-Clinical and Translational Research; IRCCS-CROB; Referral Cancer Centre of Basilicata; Rionero in Vulture (PZ) Italy
| | - Vittorio Simeon
- Laboratory of Pre-Clinical and Translational Research; IRCCS-CROB; Referral Cancer Centre of Basilicata; Rionero in Vulture (PZ) Italy
| | - Pellegrino Musto
- Laboratory of Pre-Clinical and Translational Research; IRCCS-CROB; Referral Cancer Centre of Basilicata; Rionero in Vulture (PZ) Italy
| | - Agostino Cortelezzi
- Haematology Unit; Fondazione IRCCS Ca’ Granda; Ospedale Maggiore Policlinico; Milan Italy
- Department of Clinical Sciences and Community Health; University of Milan; Milan Italy
| | - Luca Baldini
- Haematology Unit; Fondazione IRCCS Ca’ Granda; Ospedale Maggiore Policlinico; Milan Italy
- Department of Clinical Sciences and Community Health; University of Milan; Milan Italy
| | - Antonino Neri
- Haematology Unit; Fondazione IRCCS Ca’ Granda; Ospedale Maggiore Policlinico; Milan Italy
- Department of Clinical Sciences and Community Health; University of Milan; Milan Italy
| | - Marta Lionetti
- Department of Clinical Sciences and Community Health; University of Milan; Milan Italy
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54
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Brina D, Miluzio A, Ricciardi S, Clarke K, Davidsen PK, Viero G, Tebaldi T, Offenhäuser N, Rozman J, Rathkolb B, Neschen S, Klingenspor M, Wolf E, Gailus-Durner V, Fuchs H, Hrabe de Angelis M, Quattrone A, Falciani F, Biffo S. eIF6 coordinates insulin sensitivity and lipid metabolism by coupling translation to transcription. Nat Commun 2015; 6:8261. [PMID: 26383020 PMCID: PMC4595657 DOI: 10.1038/ncomms9261] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 08/04/2015] [Indexed: 02/07/2023] Open
Abstract
Insulin regulates glycaemia, lipogenesis and increases mRNA translation. Cells with reduced eukaryotic initiation factor 6 (eIF6) do not increase translation in response to insulin. The role of insulin-regulated translation is unknown. Here we show that reduction of insulin-regulated translation in mice heterozygous for eIF6 results in normal glycaemia, but less blood cholesterol and triglycerides. eIF6 controls fatty acid synthesis and glycolysis in a cell autonomous fashion. eIF6 acts by exerting translational control of adipogenic transcription factors like C/EBPβ, C/EBPδ and ATF4 that have G/C rich or uORF sequences in their 5' UTR. The outcome of the translational activation by eIF6 is a reshaping of gene expression with increased levels of lipogenic and glycolytic enzymes. Finally, eIF6 levels modulate histone acetylation and amounts of rate-limiting fatty acid synthase (Fasn) mRNA. Since obesity, type 2 diabetes, and cancer require a Fasn-driven lipogenic state, we propose that eIF6 could be a therapeutic target for these diseases.
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Affiliation(s)
- Daniela Brina
- INGM, ‘Romeo ed Enrica Invernizzi', 20122 Milano, Italy
| | | | | | - Kim Clarke
- Centre for Computational Biology and Modeling, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Peter K. Davidsen
- Centre for Computational Biology and Modeling, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Gabriella Viero
- Institute of Biophysics, 38123 Trento, Italy
- Centre for Integrative Biology, University of Trento, 38123 Trento, Italy
| | - Toma Tebaldi
- Centre for Integrative Biology, University of Trento, 38123 Trento, Italy
| | | | - Jan Rozman
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Birgit Rathkolb
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilian-University, 81377 Munich, Germany
| | - Susanne Neschen
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Martin Klingenspor
- Else Kröner-Fresenius Center, Technische Universität München, 85354 Freising, Germany
| | - Eckhard Wolf
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilian-University, 81377 Munich, Germany
| | - Valerie Gailus-Durner
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
| | - Martin Hrabe de Angelis
- German Mouse Clinic, Institute of Experimental Genetics, Helmholtz Center Munich, 85764 Neuherberg, Germany
- Center of Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
- German Center for Diabetes Research, 85764 Neuherberg, Germany
| | | | - Francesco Falciani
- Centre for Computational Biology and Modeling, Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Stefano Biffo
- INGM, ‘Romeo ed Enrica Invernizzi', 20122 Milano, Italy
- Department of Biosciences, University of Milan, 20133 Milan, Italy
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55
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Attar-Schneider O, Zismanov V, Dabbah M, Tartakover-Matalon S, Drucker L, Lishner M. Multiple myeloma and bone marrow mesenchymal stem cells' crosstalk: Effect on translation initiation. Mol Carcinog 2015; 55:1343-54. [PMID: 26293751 DOI: 10.1002/mc.22378] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Revised: 07/15/2015] [Accepted: 07/23/2015] [Indexed: 12/26/2022]
Abstract
Multiple myeloma (MM) malignant plasma cells reside in the bone marrow (BM) and convert it into a specialized pre-neoplastic niche that promotes the proliferation and survival of the cancer cells. BM resident mesenchymal stem cells (BM-MSCs) are altered in MM and in vitro studies indicate their transformation by MM proximity is within hours. The response time frame suggested that protein translation may be implicated. Thus, we assembled a co-culture model of MM cell lines with MSCs from normal donors (ND) and MM patients to test our hypothesis. The cell lines (U266, ARP-1) and BM-MSCs (ND, MM) were harvested separately after 72 h of co-culture and assayed for proliferation, death, levels of major translation initiation factors (eIF4E, eIF4GI), their targets, and regulators. Significant changes were observed: BM-MSCs (ND and MM) co-cultured with MM cell lines displayed elevated proliferation and death as well as increased expression/activity of eIF4E/eIF4GI; MM cell lines co-cultured with MM-MSCs also displayed higher proliferation and death rates coupled with augmented translation initiation factors; in contrast, MM cell lines co-cultured with ND-MSCs did not display elevated proliferation only death and had no changes in eIF4GI levels/activity. eIF4E expression was increased in one of the cell lines. Our study demonstrates that there is direct dialogue between the MM and BM-MSCs populations that includes translation initiation manipulation and critically affects cell fate. Future research should be aimed at identifying therapeutic targets that may be used to minimize the collateral damage to the cancer microenvironment and limit its recruitment into the malignant process. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
- Oshrat Attar-Schneider
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Victoria Zismanov
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Mahmoud Dabbah
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shelly Tartakover-Matalon
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Liat Drucker
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Michael Lishner
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Department of Internal Medicine, Meir Medical Center, Kfar Saba, Israel
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56
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Ren M, Zhou C, Liang H, Wang X, Xu L. RNAi-Mediated Silencing of EIF3D Alleviates Proliferation and Migration of Glioma U251 and U87MG Cells. Chem Biol Drug Des 2015; 86:715-22. [PMID: 25682860 DOI: 10.1111/cbdd.12542] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/11/2014] [Accepted: 01/05/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Mingliang Ren
- Department of Neurosurgery; Research Institute of Field Surgery; Daping Hospital; Third Military Medical University; Chongqing 400042 China
| | - Chun Zhou
- Department of Neurosurgery; Research Institute of Field Surgery; Daping Hospital; Third Military Medical University; Chongqing 400042 China
| | - Hong Liang
- Department of Neurosurgery; Research Institute of Field Surgery; Daping Hospital; Third Military Medical University; Chongqing 400042 China
| | - Xuhui Wang
- Department of Neurosurgery; Research Institute of Field Surgery; Daping Hospital; Third Military Medical University; Chongqing 400042 China
| | - Lunshan Xu
- Department of Neurosurgery; Research Institute of Field Surgery; Daping Hospital; Third Military Medical University; Chongqing 400042 China
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57
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Brina D, Miluzio A, Ricciardi S, Biffo S. eIF6 anti-association activity is required for ribosome biogenesis, translational control and tumor progression. BIOCHIMICA ET BIOPHYSICA ACTA 2015; 1849:830-5. [PMID: 25252159 DOI: 10.1016/j.bbagrm.2014.09.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/12/2014] [Accepted: 09/14/2014] [Indexed: 12/13/2022]
Abstract
Here we discuss the function of eukaryotic initiation factor 6 (eIF6; Tif6 in yeast). eIF6 binds 60S ribosomal subunits and blocks their joining to 40S. In this context, we propose that eIF6 impedes unproductive 80S formation, namely, the formation of 80S subunits without mRNA. Genetic evidence shows that eIF6 has a dual function: in yeast and mammals, nucleolar eIF6 is necessary for the biogenesis of 60S subunits. In mammals, cytoplasmic eIF6 is required for insulin and growth factor-stimulated translation. In contrast to other translation factors, eIF6 activity is not under mTOR control. The physiological significance of eIF6 impacts on cancer and on inherited Shwachman-Bodian-Diamond syndrome. eIF6 is overexpressed in specific human tumors. In a murine model of lymphomagenesis, eIF6 depletion leads to a striking increase of survival, without adverse effects. Shwachman-Bodian-Diamond syndrome is caused by loss of function of SBDS protein. In yeast, point mutations of Tif6, the yeast homolog of eIF6, rescue the quasi-lethal effect due to the loss of the SBDS homolog, Sdo1. We propose that eIF6 is a node regulator of ribosomal function and predict that prioritizing its pharmacological targeting will be of benefit in cancer and Shwachman-Bodian-Diamond syndrome. This article is part of a Special Issue entitled: Translation and Cancer.
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Affiliation(s)
- Daniela Brina
- INGM, "Romeo ed Enrica Invernizzi," Milano 20122, Italy
| | | | - Sara Ricciardi
- INGM, "Romeo ed Enrica Invernizzi," Milano 20122, Italy; DISIT, Alessandria 15100, Italy
| | - Stefano Biffo
- INGM, "Romeo ed Enrica Invernizzi," Milano 20122, Italy; DISIT, Alessandria 15100, Italy.
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58
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Davis WJ, Lehmann PZ, Li W. Nuclear PI3K signaling in cell growth and tumorigenesis. Front Cell Dev Biol 2015; 3:24. [PMID: 25918701 PMCID: PMC4394695 DOI: 10.3389/fcell.2015.00024] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 03/27/2015] [Indexed: 12/12/2022] Open
Abstract
The PI3K/Akt signaling pathway is a major driving force in a variety of cellular functions. Dysregulation of this pathway has been implicated in many human diseases including cancer. While the activity of the cytoplasmic PI3K/Akt pathway has been extensively studied, the functions of these molecules and their effector proteins within the nucleus are poorly understood. Harboring key cellular processes such as DNA replication and repair as well as nascent messenger RNA transcription, the nucleus provides a unique compartmental environment for protein–protein and protein–DNA/RNA interactions required for cell survival, growth, and proliferation. Here we summarize recent advances made toward elucidating the nuclear PI3K/Akt signaling cascade and its key components within the nucleus as they pertain to cell growth and tumorigenesis. This review covers the spatial and temporal localization of the major nuclear kinases having PI3K activities and the counteracting phosphatases as well as the role of nuclear PI3K/Akt signaling in mRNA processing and exportation, DNA replication and repair, ribosome biogenesis, cell survival, and tumorigenesis.
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Affiliation(s)
- William J Davis
- College of Medical Sciences, Washington State University Spokane, WA, USA
| | - Peter Z Lehmann
- College of Medical Sciences, Washington State University Spokane, WA, USA
| | - Weimin Li
- College of Medical Sciences, Washington State University Spokane, WA, USA
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59
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Abstract
Dysregulation of mRNA translation is a frequent feature of neoplasia. Many oncogenes and tumour suppressors affect the translation machinery, making aberrant translation a widespread characteristic of tumour cells, independent of the genetic make-up of the cancer. Therefore, therapeutic agents that target components of the protein synthesis apparatus hold promise as novel anticancer drugs that can overcome intra-tumour heterogeneity. In this Review, we discuss the role of translation in cancer, with a particular focus on the eIF4F (eukaryotic translation initiation factor 4F) complex, and provide an overview of recent efforts aiming to 'translate' these results to the clinic.
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60
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Nikolay R, Schloemer R, Mueller S, Deuerling E. Fluorescence-based monitoring of ribosome assembly landscapes. BMC Mol Biol 2015; 16:3. [PMID: 25884162 PMCID: PMC4344731 DOI: 10.1186/s12867-015-0031-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 02/03/2015] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Ribosomes and functional complexes of them have been analyzed at the atomic level. Far less is known about the dynamic assembly and degradation events that define the half-life of ribosomes and guarantee their quality control. RESULTS We developed a system that allows visualization of intact ribosomal subunits and assembly intermediates (i.e. assembly landscapes) by convenient fluorescence-based analysis. To this end, we labeled the early assembly ribosomal proteins L1 and S15 with the fluorescent proteins mAzami green and mCherry, respectively, using chromosomal gene insertion. The reporter strain harbors fluorescently labeled ribosomal subunits that operate wild type-like, as shown by biochemical and growth assays. Using genetic and chemical perturbations by depleting genes encoding the ribosomal proteins L3 and S17, respectively, or using ribosome-targeting antibiotics, we provoked ribosomal subunit assembly defects. These defects were readily identified by fluorometric analysis after sucrose density centrifugation in unprecedented resolution. CONCLUSION This strategy is useful to monitor and characterize subunit specific assembly defects caused by ribosome-targeting drugs that are currently used and to characterize new molecules that affect ribosome assembly and thereby constitute new classes of antibacterial agents.
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Affiliation(s)
- Rainer Nikolay
- Molecular Microbiology, University of Konstanz, Constance, 78457, Germany.
- Current address: Institute of Medical Physics and Biophysics, Charité-Universitaetsmedizin Berlin, Berlin, 10117, Germany.
| | - Renate Schloemer
- Molecular Microbiology, University of Konstanz, Constance, 78457, Germany.
| | - Silke Mueller
- Screening Center Konstanz, University of Konstanz, Constance, 78457, Germany.
| | - Elke Deuerling
- Molecular Microbiology, University of Konstanz, Constance, 78457, Germany.
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61
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Abstract
The proteome of cells is synthesized by ribosomes, complex ribonucleoproteins that in eukaryotes contain 79-80 proteins and four ribosomal RNAs (rRNAs) more than 5,400 nucleotides long. How these molecules assemble together and how their assembly is regulated in concert with the growth and proliferation of cells remain important unanswered questions. Here, we review recently emerging principles to understand how eukaryotic ribosomal proteins drive ribosome assembly in vivo. Most ribosomal proteins assemble with rRNA cotranscriptionally; their association with nascent particles is strengthened as assembly proceeds. Each subunit is assembled hierarchically by sequential stabilization of their subdomains. The active sites of both subunits are constructed last, perhaps to prevent premature engagement of immature ribosomes with active subunits. Late-assembly intermediates undergo quality-control checks for proper function. Mutations in ribosomal proteins that affect mostly late steps lead to ribosomopathies, diseases that include a spectrum of cell type-specific disorders that often transition from hypoproliferative to hyperproliferative growth.
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Affiliation(s)
- Jesus de la Cruz
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, E-41013 Sevilla, Spain
- Departamento de Genetica, Universidad de Sevilla, E-41013 Sevilla, Spain
| | - Katrin Karbstein
- Department of Cancer Biology, The Scripps Research Institute, Jupiter, Florida 33458
| | - John L Woolford
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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62
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Abstract
Background The majority of genetic biomarkers for human cancers are defined by statistical screening of high-throughput genomics data. While a large number of genetic biomarkers have been proposed for diagnostic and prognostic applications, only a small number have been applied in the clinic. Similarly, the use of proteomics methods for the discovery of cancer biomarkers is increasing. The emerging field of proteogenomics seeks to enrich the value of genomics and proteomics approaches by studying the intersection of genomics and proteomics data. This task is challenging due to the complex nature of transcriptional and translation regulatory mechanisms and the disparities between genomic and proteomic data from the same samples. In this study, we have examined tumor antigens as potential biomarkers for breast cancer using genomics and proteomics data from previously reported laser capture microdissected ER+ tumor samples. Results We applied proteogenomic analyses to study the genetic aberrations of 32 tumor antigens determined in the proteomic data. We found that tumor antigens that are aberrantly expressed at the genetic level and expressed at the protein level, are likely involved in perturbing pathways directly linked to the hallmarks of cancer. The results found by proteogenomic analysis of the 32 tumor antigens studied here, capture largely the same pathway irregularities as those elucidated from large-scale screening of genomics analyses, where several thousands of genes are often found to be perturbed. Conclusion Tumor antigens are a group of proteins recognized by the cells of the immune system. Specifically, they are recognized in tumor cells where they are present in larger than usual amounts, or are physiochemically altered to a degree at which they no longer resemble native human proteins. This proteogenomic analysis of 32 tumor antigens suggests that tumor antigens have the potential to be highly specific biomarkers for different cancers.
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63
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Madden JM, Mueller KL, Bollig-Fischer A, Stemmer P, Mattingly RR, Boerner JL. Abrogating phosphorylation of eIF4B is required for EGFR and mTOR inhibitor synergy in triple-negative breast cancer. Breast Cancer Res Treat 2014; 147:283-93. [PMID: 25129346 DOI: 10.1007/s10549-014-3102-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Accepted: 08/10/2014] [Indexed: 11/27/2022]
Abstract
Triple-negative breast cancer (TNBC) patients suffer from a highly malignant and aggressive disease. They have a high rate of relapse and often develop resistance to standard chemotherapy. Many TNBCs have elevated epidermal growth factor receptor (EGFR) but are resistant to EGFR inhibitors as monotherapy. In this study, we sought to find a combination therapy that could sensitize TNBC to EGFR inhibitors. Phospho-mass spectrometry was performed on the TNBC cell line, BT20, treated with 0.5 μM gefitinib. Immunoblotting measured protein levels and phosphorylation. Colony formation and growth assays analyzed the treatment on cell proliferation, while MTT assays determined the synergistic effect of inhibitor combination. A Dual-Luciferase reporter gene plasmid measured translation. All statistical analysis was done on CalucuSyn and GraphPad Prism using ANOVAs. Phospho-proteomics identified the mTOR pathway to be of interest in EGFR inhibitor resistance. In our studies, combining gefitinib and temsirolimus decreased cell growth and survival in a synergistic manner. Our data identified eIF4B, as a potentially key fragile point in EGFR and mTOR inhibitor synergy. Decreased eIF4B phosphorylation correlated with drops in growth, viability, clonogenic survival, and cap-dependent translation. Taken together, these data suggest EGFR and mTOR inhibitors abrogate growth, viability, and survival via disruption of eIF4B phosphorylation leading to decreased translation in TNBC cell lines. Further, including an mTOR inhibitor along with an EGFR inhibitor in TNBC with increased EGFR expression should be further explored. Additionally, translational regulation may play an important role in regulating EGFR and mTOR inhibitor synergy and warrant further investigation.
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Affiliation(s)
- Julie M Madden
- Departments of Oncology, Wayne State University, 4100 John R. St, Detroit, MI, 48201, USA
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64
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D’Angelo L, Piazzi G, Pacilli A, Prossomariti A, Fazio C, Montanaro L, Graziani G, Fogliano V, Munarini A, Bianchi F, Belluzzi A, Bazzoli F, Ricciardiello L. A combination of eicosapentaenoic acid-free fatty acid, epigallocatechin-3-gallate and proanthocyanidins has a strong effect on mTOR signaling in colorectal cancer cells. Carcinogenesis 2014; 35:2314-20. [DOI: 10.1093/carcin/bgu173] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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65
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McKinney C, Zavadil J, Bianco C, Shiflett L, Brown S, Mohr I. Global reprogramming of the cellular translational landscape facilitates cytomegalovirus replication. Cell Rep 2013; 6:9-17. [PMID: 24373965 DOI: 10.1016/j.celrep.2013.11.045] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/31/2013] [Accepted: 11/26/2013] [Indexed: 12/27/2022] Open
Abstract
Unlike many viruses that suppress cellular protein synthesis, host mRNA translation and polyribosome formation are stimulated by human cytomegalovirus (HCMV). How HCMV impacts the translationally regulated cellular mRNA repertoire and its contribution to virus biology remains unknown. Using polysome profiling, we show that HCMV presides over the cellular translational landscape, selectively accessing the host genome to extend its own coding capacity and regulate virus replication. Expression of the HCMV UL38 mTORC1-activator partially recapitulates these translational alterations in uninfected cells. The signature of cellular mRNAs translationally stimulated by HCMV resembles pathophysiological states (such as cancer) where translation initiation factor levels or activity increase. In contrast, cellular mRNAs repressed by HCMV include those involved in differentiation and the immune response. Surprisingly, interfering with the virus-induced activation of cellular mRNA translation can either limit or enhance HCMV growth. The unanticipated extent to which HCMV specifically manipulates host mRNA translation may aid in understanding its association with complex inflammatory disorders and cancer.
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Affiliation(s)
- Caleb McKinney
- Department of Microbiology and NYU Cancer Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Jiri Zavadil
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA; NYU Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, NY 10016, USA
| | - Christopher Bianco
- Department of Microbiology and NYU Cancer Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Lora Shiflett
- Department of Microbiology and NYU Cancer Institute, New York University School of Medicine, New York, NY 10016, USA
| | - Stuart Brown
- NYU Center for Health Informatics and Bioinformatics, New York University School of Medicine, New York, NY 10016, USA
| | - Ian Mohr
- Department of Microbiology and NYU Cancer Institute, New York University School of Medicine, New York, NY 10016, USA.
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