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Rubio A, Garland GD, Sfakianos A, Harvey RF, Willis AE. Aberrant protein synthesis and cancer development: The role of canonical eukaryotic initiation, elongation and termination factors in tumorigenesis. Semin Cancer Biol 2022; 86:151-165. [PMID: 35487398 DOI: 10.1016/j.semcancer.2022.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/11/2022] [Accepted: 04/20/2022] [Indexed: 01/27/2023]
Abstract
In tumourigenesis, oncogenes or dysregulated tumour suppressor genes alter the canonical translation machinery leading to a reprogramming of the translatome that, in turn, promotes the translation of selected mRNAs encoding proteins involved in proliferation and metastasis. It is therefore unsurprising that abnormal expression levels and activities of eukaryotic initiation factors (eIFs), elongation factors (eEFs) or termination factors (eRFs) are associated with poor outcome for patients with a wide range of cancers. In this review we discuss how RNA binding proteins (RBPs) within the canonical translation factor machinery are dysregulated in cancers and how targeting such proteins is leading to new therapeutic avenues.
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Affiliation(s)
- Angela Rubio
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Gavin D Garland
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Aristeidis Sfakianos
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Robert F Harvey
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK.
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Zhang F, Waheed S, Armato U, Wu J, Zhang C, Li Z. eIF6 as a Promising Diagnostic and Prognostic Biomarker for Poorer Survival of Cutaneous Melanoma. Front Oncol 2022; 12:848346. [PMID: 35707354 PMCID: PMC9189357 DOI: 10.3389/fonc.2022.848346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 04/25/2022] [Indexed: 11/16/2022] Open
Abstract
Background Skin cutaneous melanoma (SKCM) is the deadliest skin cancer and has the most rapidly increasing incidences among all cancer types. Previous research elucidated that melanoma can only be successfully treated with surgical abscission in the early stage. Therefore, reliable and specific biomarkers are crucial to melanoma diagnosis since it often looks like nevi in the clinical manifestations. Moreover, identifying key genes contributing to melanoma progression is also highly regarded as a potential strategy for melanoma therapy. In this respect, translation initiator eIF6 has been proved as a pro-tumor factor in several cancers. However, the role of eIF6 in the skin cutaneous melanoma progression and its potential as a prognostic marker is still unexplored. Methods The immunochemical analysis of clinical specimens were served to assess eIF6 expression levels. Gene Expression Profiling Interactive Analysis (GEPIA) database consultations allowed us to find the survival rates of the eIF6-overexpressed patients. eIF6 cellular effects were evaluated in an eIF6-overexpressed A375 cell line constructed with a lentivirus. The analysis of down-stream effectors or pathways was conducted using C-Bioportal and STRING databases. Results Our results revealed that eIF6 was highly over-expressed in melanomas compared to normal skin specimens, and thus the abnormally high level of eIF6 can be a diagnostic marker for melanoma. The in silica analysis indicated that patients with eIF6 over-expression had lower survival rates than that low-expression in SKCM. Meanwhile, similar results also could be found in the other four types of cancers. In vitro, over-expression of eIF6 increased the proliferation and migration of melanoma cells. Correspondingly, pan-cancer clustering analysis indicated the expression level of intermediate filament proteins was correlated with that of eIF6 expression. In our study, all over-expressed keratin proteins, in accordance with over-expressed eIF6, had a negative correlation with melanoma prognosis. Moreover, the decreased methylation level of keratin genes suggested a new potential regulation mode of eIF6. Conclusions The up-regulated eIF6 could be a potential diagnostic and prognostic biomarker of melanoma. This study also provides insights into the potential role of eIF6 in pan-cancer epigenetic regulation.
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Affiliation(s)
- Fangyingnan Zhang
- School of Biomedical Engineering, Sun Yat-sen University, Guangzhou, China
- Department of Burn and Plastic Surgery, Shenzhen Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, China
| | - Saquib Waheed
- Department of Burn and Plastic Surgery, Shenzhen Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, China
| | - Ubaldo Armato
- Department of Burn and Plastic Surgery, Shenzhen Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, China
| | - Jun Wu
- School of Biomedical Engineering, Sun Yat-sen University, Guangzhou, China
- Department of Burn and Plastic Surgery, Shenzhen Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, China
| | - Chao Zhang
- School of Biomedical Engineering, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Zhibin Li, ; Chao Zhang,
| | - Zhibin Li
- Department of Burn and Plastic Surgery, Shenzhen Institute of Translational Medicine, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, China
- *Correspondence: Zhibin Li, ; Chao Zhang,
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Sun L, Liu S, Wang X, Zheng X, Chen Y, Shen H. eIF6 promotes the malignant progression of human hepatocellular carcinoma via the mTOR signaling pathway. J Transl Med 2021; 19:216. [PMID: 34016142 PMCID: PMC8139032 DOI: 10.1186/s12967-021-02877-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 05/05/2021] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Eukaryotic translation initiation factor 6 (eIF6) has a crucial function in the maturation of 60S ribosomal subunits, and it controls the initiation of protein translation. Although emerging studies indicate that eIF6 is aberrantly expressed in various types of cancers, the functions and underlying molecular mechanisms of eIF6 in the pathological progression of hepatocellular carcinoma (HCC) remain unclear. This study aimed to evaluate the potential diagnostic and prognostic value of eIF6 in patients with HCC. METHODS HCC samples enrolled from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and our cohort were used to explore the role and mechanism of eIF6 in HCC. The diagnostic power of eIF6 was verified by receiver operating characteristic curve (ROC) analysis and its prognostic value was assessed by Kaplan-Meier analysis, and then related biological functions of eIF6 were determined in vitro and in vivo cancer models. In addition, potential molecular mechanism of eIF6 in HCC was unveiled by the gene set enrichment analysis and western blot assay. RESULTS We demonstrated that eIF6 expression was markedly increased in HCC, and elevated eIF6 expression correlated with pathological progression of HCC. Besides, eIF6 served as not only a new diagnostic biomarker but also an independent risk factor for OS in HCC patients. Functional studies indicated that the deletion of eIF6 displayed tumor-suppressor activity in HCC cells. Furthermore, we found that eIF6 could activate the mTOR-related signaling pathway and regulate the expression level of its target genes, such as CCND1, CDK4, CDK6, MYC, CASP3 and CTNNBL1, and these activities promoted proliferation and invasion of HCC cells. CONCLUSIONS The findings of this study provided a novel basis for understanding the potential role of eIF6 in promoting tumor growth and invasion, and exploited a promising strategy for improving diagnosis and prognosis of HCC.
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Affiliation(s)
- Liping Sun
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Shuguang Liu
- Department of Pathology, The Eighth Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
| | - Xiaopai Wang
- Department of Pathology, School of Medicine, Guangzhou First People's Hospital, South China University of Technology, Guangzhou, China
| | - Xuefeng Zheng
- Department of Anatomy, Neuroscience Laboratory for Cognitive and Developmental Disorders, Medical College of Jinan University, Guangzhou, China
| | - Ya Chen
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Hong Shen
- Department of Pathology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China. .,Department of Pathology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Mancini A, Xavier-Magalhães A, Woods WS, Nguyen KT, Amen AM, Hayes JL, Fellmann C, Gapinske M, McKinney AM, Hong C, Jones LE, Walsh KM, Bell RJA, Doudna JA, Costa BM, Song JS, Perez-Pinera P, Costello JF. Disruption of the β1L Isoform of GABP Reverses Glioblastoma Replicative Immortality in a TERT Promoter Mutation-Dependent Manner. Cancer Cell 2018; 34:513-528.e8. [PMID: 30205050 PMCID: PMC6135086 DOI: 10.1016/j.ccell.2018.08.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 07/02/2018] [Accepted: 08/03/2018] [Indexed: 12/27/2022]
Abstract
TERT promoter mutations reactivate telomerase, allowing for indefinite telomere maintenance and enabling cellular immortalization. These mutations specifically recruit the multimeric ETS factor GABP, which can form two functionally independent transcription factor species: a dimer or a tetramer. We show that genetic disruption of GABPβ1L (β1L), a tetramer-forming isoform of GABP that is dispensable for normal development, results in TERT silencing in a TERT promoter mutation-dependent manner. Reducing TERT expression by disrupting β1L culminates in telomere loss and cell death exclusively in TERT promoter mutant cells. Orthotopic xenografting of β1L-reduced, TERT promoter mutant glioblastoma cells rendered lower tumor burden and longer overall survival in mice. These results highlight the critical role of GABPβ1L in enabling immortality in TERT promoter mutant glioblastoma.
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Affiliation(s)
- Andrew Mancini
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA
| | - Ana Xavier-Magalhães
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA; Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, 4710-057 Braga, Portugal
| | - Wendy S Woods
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Kien-Thiet Nguyen
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA
| | - Alexandra M Amen
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA; Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Josie L Hayes
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA
| | - Christof Fellmann
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Michael Gapinske
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Andrew M McKinney
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA
| | - Chibo Hong
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA
| | - Lindsey E Jones
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA
| | - Kyle M Walsh
- Division of Neuroepidemiology, Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA
| | - Robert J A Bell
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA; Department of Chemistry, University of California, Berkeley, CA 94720, USA; Innovative Genomics Institute, University of California, Berkeley, CA 94720, USA; MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Howard Hughes Medical Institute (HHMI), Berkeley, CA 94720, USA
| | - Bruno M Costa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal; ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, 4710-057 Braga, Portugal
| | - Jun S Song
- Department of Physics, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Pablo Perez-Pinera
- Department of Bioengineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA; Carl R. Woese Institute for Genomic Biology, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Joseph F Costello
- Department of Neurological Surgery, University of California, San Francisco, CA 94158, USA.
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Patra P, Izawa T, Pena-Castillo L. REPA: Applying Pathway Analysis to Genome-Wide Transcription Factor Binding Data. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2018; 15:1270-1283. [PMID: 27019499 DOI: 10.1109/tcbb.2015.2453948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Pathway analysis has been extensively applied to aid in the interpretation of the results of genome-wide transcription profiling studies, and has been shown to successfully find associations between the biological phenomena under study and biological pathways. There are two widely used approaches of pathway analysis: over-representation analysis, and gene set analysis. Recently genome-wide transcription factor binding data has become widely available allowing for the application of pathway analysis to this type of data. In this work, we developed regulatory enrichment pathway analysis (REPA) to apply gene set analysis to genome-wide transcription factor binding data to infer associations between transcription factors and biological pathways. We used the transcription factor binding data generated by the ENCODE project, and gene sets from the Molecular Signatures and KEGG databases. Our results showed that 54 percent of the predictions examined have literature support and that REPA's recall is roughly 54 percent. This level of precision is promising as several of REPA's predictions are expected to be novel and can be used to guide new research avenues. In addition, the results of our case studies showed that REPA enhances the interpretation of genome-wide transcription profiling studies by suggesting putative regulators behind the observed transcriptional responses.
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Tan TCJ, Knight J, Sbarrato T, Dudek K, Willis AE, Zamoyska R. Suboptimal T-cell receptor signaling compromises protein translation, ribosome biogenesis, and proliferation of mouse CD8 T cells. Proc Natl Acad Sci U S A 2017; 114:E6117-E6126. [PMID: 28696283 PMCID: PMC5544288 DOI: 10.1073/pnas.1700939114] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Global transcriptomic and proteomic analyses of T cells have been rich sources of unbiased data for understanding T-cell activation. Lack of full concordance of these datasets has illustrated that important facets of T-cell activation are controlled at the level of translation. We undertook translatome analysis of CD8 T-cell activation, combining polysome profiling and microarray analysis. We revealed that altering T-cell receptor stimulation influenced recruitment of mRNAs to heavy polysomes and translation of subsets of genes. A major pathway that was compromised, when TCR signaling was suboptimal, was linked to ribosome biogenesis, a rate-limiting factor in both cell growth and proliferation. Defective TCR signaling affected transcription and processing of ribosomal RNA precursors, as well as the translation of specific ribosomal proteins and translation factors. Mechanistically, IL-2 production was compromised in weakly stimulated T cells, affecting the abundance of Myc protein, a known regulator of ribosome biogenesis. Consequently, weakly activated T cells showed impaired production of ribosomes and a failure to maintain proliferative capacity after stimulation. We demonstrate that primary T cells respond to various environmental cues by regulating ribosome biogenesis and mRNA translation at multiple levels to sustain proliferation and differentiation.
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Affiliation(s)
- Thomas C J Tan
- Institute of Immunology and Infection Research, Ashworth Laboratories, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom
| | - John Knight
- Medical Research Council Toxicology Unit, Leicester LE1 9HN, United Kingdom
| | - Thomas Sbarrato
- Medical Research Council Toxicology Unit, Leicester LE1 9HN, United Kingdom
| | - Kate Dudek
- Medical Research Council Toxicology Unit, Leicester LE1 9HN, United Kingdom
| | - Anne E Willis
- Medical Research Council Toxicology Unit, Leicester LE1 9HN, United Kingdom
| | - Rose Zamoyska
- Institute of Immunology and Infection Research, Ashworth Laboratories, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom;
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Zhu W, Li GX, Chen HL, Liu XY. The role of eukaryotic translation initiation factor 6 in tumors. Oncol Lett 2017; 14:3-9. [PMID: 28693127 PMCID: PMC5494901 DOI: 10.3892/ol.2017.6161] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 10/26/2016] [Indexed: 12/28/2022] Open
Abstract
Eukaryotic translation initiation factor 6 (eIF6) affects the maturation of 60S ribosomal subunits. Found in yeast and mammalian cells, eIF6 is primarily located in the cytoplasm of mammalian cells. Emerging evidence has demonstrated that the dysregulated expression of eIF6 is important in several types of human cancer, including head and neck carcinoma, colorectal cancer, non-small cell lung cancer and ovarian serous adenocarcinoma. However, the molecular mechanisms by which eIF6 functions during tumor formation and progression remain elusive. The present review focuses on recent progress in terms of the mechanisms and functions of eIF6 in human tumorigenesis or cancer cell lines, along with the signal transduction pathways in which this novel translation initiation factor may participate. Oncogenic Ras activates Notch-1 and promotes transcription of eIF6 via a recombining binding protein suppressor of Hairless-dependent mechanism. In addition, overexpression of eIF6 results in aberrant activation of the Wnt/β-catenin signaling pathway. Similarly, overexpressed eIF6 regulates its downstream modulator, cell division control protein 42, which in turn affects oncogenesis. Finally, the potential of eIF6 as a biomarker for diagnosis of cancer is also discussed in the present review.
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Affiliation(s)
- Wei Zhu
- Department of Pathology, Guangdong Medical University, Dongguan, Guangdong 523808, P.R. China
| | - Gui Xian Li
- Department of Pathology, Guangdong Medical University, Dongguan, Guangdong 523808, P.R. China
| | - Hong Lang Chen
- Department of Pharmacology, Guangdong Medical University, Dongguan, Guangdong 523808, P.R. China
| | - Xing Yan Liu
- Sino-American Cancer Research Institute, Guangdong Medical University, Dongguan, Guangdong 523808, P.R. China
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Ricciardi S, Miluzio A, Brina D, Clarke K, Bonomo M, Aiolfi R, Guidotti LG, Falciani F, Biffo S. Eukaryotic translation initiation factor 6 is a novel regulator of reactive oxygen species-dependent megakaryocyte maturation. J Thromb Haemost 2015; 13:2108-18. [PMID: 26391622 DOI: 10.1111/jth.13150] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 09/05/2015] [Indexed: 01/06/2023]
Abstract
BACKGROUND Ribosomopathies constitute a class of inherited disorders characterized by defects in ribosome biogenesis and function. Classically, bone marrow (BM) failure is a clinical symptom shared between these syndromes, including Shwachman-Bodian-Diamond syndrome (SBDS). Eukaryotic translation initiation factor 6 (eIF6) is a critical translation factor that rescues the quasilethal effect of the loss of the SBDS protein. OBJECTIVES To determine whether eIF6 activity is necessary for BM development. METHODS We used eIF6(+/-) mice and primary BM megakaryocytes to investigate the involvement of eIF6 in the regulation of hematopoiesis. RESULTS We provide evidence that reduced eIF6 expression negatively impacts on megakaryopoiesis. We show that inhibition of eIF6 leads to a reduction in cell size and mean ploidy level of megakaryocytes and a delay in megakaryocyte maturation by blocking the G1 /S transition. Consistent with this phenotype, only few megakaryocyte-forming proplatelets were found in eIF6(+/-) cells. We also discovered that, in eIF6(+/-) cells, the steady-state abundance of mitochondrial respiratory chain complex I-encoding mRNAs is decreased, resulting in decreased reactive oxygen species (ROS) production. Intriguingly, connectivity map analysis showed that eIF6-mediated changes overlap with specific translational inhibitors. eIF6 is a translation factor acting downstream of insulin/phorbol 12-myristate 13-acetate (PMA) stimulation. PMA treatment significantly restored eIF6(+/-) megakaryocyte maturation, indicating that activation of eIF6 is essential for the rescue of the phenotype. CONCLUSIONS Taken together, our results show a role for eIF6-driven translation in megakaryocyte development, and unveil the novel connection between translational control and ROS production in this cell subset.
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Affiliation(s)
- S Ricciardi
- Molecular Histology and Cell Growth Unit, National Institute of Molecular Genetics - INGM, 'Romeo ed Enrica Invernizzi', Milan, Italy
| | - A Miluzio
- Molecular Histology and Cell Growth Unit, National Institute of Molecular Genetics - INGM, 'Romeo ed Enrica Invernizzi', Milan, Italy
| | - D Brina
- Molecular Histology and Cell Growth Unit, National Institute of Molecular Genetics - INGM, 'Romeo ed Enrica Invernizzi', Milan, Italy
| | - K Clarke
- Centre for Computational Biology and Modeling, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - M Bonomo
- Centre for Computational Biology and Modeling, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - R Aiolfi
- Immunopathology Unit, San Raffaele Scientific Institute, Milan, Italy
| | - L G Guidotti
- Immunopathology Unit, San Raffaele Scientific Institute, Milan, Italy
| | - F Falciani
- Centre for Computational Biology and Modeling, Institute of Integrative Biology, University of Liverpool, Liverpool, UK
| | - S Biffo
- Molecular Histology and Cell Growth Unit, National Institute of Molecular Genetics - INGM, 'Romeo ed Enrica Invernizzi', Milan, Italy
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Benelli D, Cialfi S, Pinzaglia M, Talora C, Londei P. The translation factor eIF6 is a Notch-dependent regulator of cell migration and invasion. PLoS One 2012; 7:e32047. [PMID: 22348144 PMCID: PMC3279413 DOI: 10.1371/journal.pone.0032047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 01/21/2012] [Indexed: 11/18/2022] Open
Abstract
A growing body of evidence indicates that protein factors controlling translation play an important role in tumorigenesis. The protein known as eIF6 is a ribosome anti-association factor that has been implicated in translational initiation and in ribosome synthesis. Over-expression of eIF6 is observed in many natural tumours, and causes developmental and differentiation defects in certain animal models. Here we show that the transcription of the gene encoding eIF6 is modulated by the receptor Notch-1, a protein involved in embryonic development and cell differentiation, as well as in many neoplasms. Inhibition of Notch-1 signalling by γ-secretase inhibitors slowed down cell-cycle progression and reduced the amount of eIF6 in lymphoblastoid and ovarian cancer cell lines. Cultured ovarian cancer cell lines engineered to stably over-expressing eIF6 did not show significant changes in proliferation rate, but displayed an enhanced motility and invasive capacity. Inhibition of Notch-1 signalling in the cells over-expressing eIF6 was effective in slowing down the cell cycle, but did not reduce cell migration and invasion. On the whole, the results suggest that eIF6 is one of the downstream effectors of Notch-1 in the pathway that controls cell motility and invasiveness.
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Affiliation(s)
- Dario Benelli
- Department of Cellular Biotechnologies and Haematology, University of Rome Sapienza, Rome, Italy
| | - Samantha Cialfi
- Department of Pediatrics and Infantile Neuropsychiatry, University of Rome Sapienza, Rome, Italy
| | - Michela Pinzaglia
- Department of Cellular Biotechnologies and Haematology, University of Rome Sapienza, Rome, Italy
| | - Claudio Talora
- Department of Molecular Medicine, University of Rome Sapienza, Rome, Italy
| | - Paola Londei
- Department of Cellular Biotechnologies and Haematology, University of Rome Sapienza, Rome, Italy
- * E-mail:
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Miluzio A, Beugnet A, Grosso S, Brina D, Mancino M, Campaner S, Amati B, de Marco A, Biffo S. Impairment of cytoplasmic eIF6 activity restricts lymphomagenesis and tumor progression without affecting normal growth. Cancer Cell 2011; 19:765-75. [PMID: 21665150 DOI: 10.1016/j.ccr.2011.04.018] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 02/14/2011] [Accepted: 04/29/2011] [Indexed: 12/13/2022]
Abstract
Eukaryotic Initiation Factor 6 (eIF6) controls translation by regulating 80S subunit formation. eIF6 is overexpressed in tumors. Here, we demonstrate that eIF6 inactivation delays tumorigenesis and reduces tumor growth in vivo. eIF6(+/-) mice resist to Myc-induced lymphomagenesis and have prolonged tumor-free survival and reduced tumor growth. eIF6(+/-) mice are also protected by p53 loss. Myc-driven lymphomas contain PKCβII and phosphorylated eIF6; eIF6 is phosphorylated by tumor-derived PKCβII, but not by the eIF4F activator mTORC1. Mutation of PKCβII phosphosite of eIF6 reduces tumor growth. Thus, eIF6 is a rate-limiting controller of initiation of translation, able to affect tumorigenesis and tumor growth. Modulation of eIF6 activity, independent from eIF4F complex, may lead to a therapeutical avenue in tumor therapy.
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Affiliation(s)
- Annarita Miluzio
- Histology and Cell Growth, San Raffaele Scientific Institute, Milan, Italy
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Baughman JM, Nilsson R, Gohil VM, Arlow DH, Gauhar Z, Mootha VK. A computational screen for regulators of oxidative phosphorylation implicates SLIRP in mitochondrial RNA homeostasis. PLoS Genet 2009; 5:e1000590. [PMID: 19680543 PMCID: PMC2721412 DOI: 10.1371/journal.pgen.1000590] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2009] [Accepted: 07/09/2009] [Indexed: 11/18/2022] Open
Abstract
The human oxidative phosphorylation (OxPhos) system consists of approximately 90 proteins encoded by nuclear and mitochondrial genomes and serves as the primary cellular pathway for ATP biosynthesis. While the core protein machinery for OxPhos is well characterized, many of its assembly, maturation, and regulatory factors remain unknown. We exploited the tight transcriptional control of the genes encoding the core OxPhos machinery to identify novel regulators. We developed a computational procedure, which we call expression screening, which integrates information from thousands of microarray data sets in a principled manner to identify genes that are consistently co-expressed with a target pathway across biological contexts. We applied expression screening to predict dozens of novel regulators of OxPhos. For two candidate genes, CHCHD2 and SLIRP, we show that silencing with RNAi results in destabilization of OxPhos complexes and a marked loss of OxPhos enzymatic activity. Moreover, we show that SLIRP plays an essential role in maintaining mitochondrial-localized mRNA transcripts that encode OxPhos protein subunits. Our findings provide a catalogue of potential novel OxPhos regulators that advance our understanding of the coordination between nuclear and mitochondrial genomes for the regulation of cellular energy metabolism. Respiratory chain disorders represent the largest class of inborn errors in metabolism affecting 1 in every 5,000 individuals. Biochemically, these disorders are characterized by a breakdown in the cellular process called oxidative phosphorylation (OxPhos), which is responsible for generating most of the cell's energy in the form of ATP. Sadly, for approximately 50% of patients diagnosed, we do not know the molecular cause behind these disorders. One possible reason for our limited diagnostic capability is that these patients harbor a mutation in a gene that is not known to act in the OxPhos pathway. We therefore designed a computational strategy called expression screening that integrates publicly available genome-wide gene expression data to predict new genes that may play a role in OxPhos biology. We identified several uncharacterized genes that were strongly predicted by our procedure to function in the OxPhos pathway and experimentally validated two genes, SLIRP and CHCHD2, as being essential for OxPhos function. These genes, as well as others predicted by expression screening to regulate OxPhos, represent a valuable resource for identifying the molecular underpinnings of respiratory chain disorders.
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Affiliation(s)
- Joshua M. Baughman
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Roland Nilsson
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Vishal M. Gohil
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Daniel H. Arlow
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Zareen Gauhar
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Vamsi K. Mootha
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, Massachusetts, United States of America
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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12
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Miluzio A, Beugnet A, Volta V, Biffo S. Eukaryotic initiation factor 6 mediates a continuum between 60S ribosome biogenesis and translation. EMBO Rep 2009; 10:459-65. [PMID: 19373251 DOI: 10.1038/embor.2009.70] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 03/24/2009] [Indexed: 12/11/2022] Open
Abstract
Eukaryotic ribosome biogenesis and translation are linked processes that limit the rate of cell growth. Although ribosome biogenesis and translation are mainly controlled by distinct factors, eukaryotic initiation factor 6 (eIF6) has been found to regulate both processes. eIF6 is a necessary protein with a unique anti-association activity, which prevents the interaction of 40S ribosomal subunits with 60S subunits through its binding to 60S ribosomes. In the nucleolus, eIF6 is a component of the pre-ribosomal particles and is required for the biogenesis of 60S subunits, whereas in the cytoplasm it mediates translation downstream from growth factors. The translational activity of eIF6 could be due to its anti-association properties, which are regulated by post-translational modifications; whether this anti-association activity is required for the biogenesis and nuclear export of ribosomes is unknown. eIF6 is necessary for tissue-specific growth and oncogene-driven transformation, and could be a new rate-limiting step for the initiation of translation.
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Affiliation(s)
- Annarita Miluzio
- Laboratory of Molecular Histology and Cell Growth, Division of Oncology, San Raffaele Scientific Institute, Via Olgettina 58, 20132 Milano, Italy
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