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Jacquemin C, El Orch W, Diaz O, Lalande A, Aublin-Gex A, Jacolin F, Toesca J, Si-Tahar M, Mathieu C, Lotteau V, Perrin-Cocon L, Vidalain PO. Pharmacological induction of the hypoxia response pathway in Huh7 hepatoma cells limits proliferation but increases resilience under metabolic stress. Cell Mol Life Sci 2024; 81:320. [PMID: 39078527 PMCID: PMC11335246 DOI: 10.1007/s00018-024-05361-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 06/25/2024] [Accepted: 07/12/2024] [Indexed: 07/31/2024]
Abstract
The hypoxia response pathway enables adaptation to oxygen deprivation. It is mediated by hypoxia-inducible factors (HIF), which promote metabolic reprogramming, erythropoiesis, angiogenesis and tissue remodeling. This led to the successful development of HIF-inducing drugs for treating anemia and some of these molecules are now in clinic. However, elevated levels of HIFs are frequently associated with tumor growth, poor prognosis, and drug resistance in various cancers, including hepatocellular carcinoma (HCC). Consequently, there are concerns regarding the recommendation of HIF-inducing drugs in certain clinical situations. Here, we analyzed the effects of two HIF-inducing drugs, Molidustat and Roxadustat, in the well-characterized HCC cell line Huh7. These drugs increased HIF-1α and HIF-2α protein levels which both participate in inducing hypoxia response genes such as BNIP3, SERPINE1, LDHA or EPO. Combined transcriptomics, proteomics and metabolomics showed that Molidustat increased the expression of glycolytic enzymes, while the mitochondrial network was fragmented and cellular respiration decreased. This metabolic remodeling was associated with a reduced proliferation and a lower demand for pyrimidine supply, but an increased ability of cells to convert pyruvate to lactate. This was accompanied by a higher resistance to the inhibition of mitochondrial respiration by antimycin A, a phenotype confirmed in Roxadustat-treated Huh7 cells and Molidustat-treated hepatoblastoma cells (Huh6 and HepG2). Overall, this study shows that HIF-inducing drugs increase the metabolic resilience of liver cancer cells to metabolic stressors, arguing for careful monitoring of patients treated with HIF-inducing drugs, especially when they are at risk of liver cancer.
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Affiliation(s)
- Clémence Jacquemin
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
| | - Walid El Orch
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
| | - Olivier Diaz
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
| | - Alexandre Lalande
- CIRI, Centre International de Recherche en Infectiologie, Team NeuroInvasion, Tropism and Viral Encephalitis, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
| | - Anne Aublin-Gex
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
| | - Florentine Jacolin
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
| | - Johan Toesca
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
| | - Mustapha Si-Tahar
- Centre d'Etude des Pathologies Respiratoires (CEPR), Faculty of Medecine, Inserm, U1100, 37000, Tours, France
| | - Cyrille Mathieu
- CIRI, Centre International de Recherche en Infectiologie, Team NeuroInvasion, Tropism and Viral Encephalitis, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
| | - Vincent Lotteau
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France
- Laboratoire P4 INSERM-Jean Mérieux, Lyon, France
| | - Laure Perrin-Cocon
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France.
| | - Pierre-Olivier Vidalain
- CIRI, Centre International de Recherche en Infectiologie, Team Viral Infection, Metabolism and Immunity, Univ Lyon, Inserm, U1111, CNRS, UMR5308, Université Claude Bernard Lyon 1, Ecole Normale Supérieure de Lyon, 69007, Lyon, France.
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2
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Ajouaou Y, Azouz A, Taquin A, Denanglaire S, Hussein H, Krayem M, Andris F, Moser M, Goriely S, Leo O. The oxygen sensor Prolyl hydroxylase domain 2 regulates the in vivo suppressive capacity of regulatory T cells. eLife 2022; 11:70555. [PMID: 35192456 PMCID: PMC8896828 DOI: 10.7554/elife.70555] [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: 06/12/2021] [Accepted: 02/18/2022] [Indexed: 11/26/2022] Open
Abstract
The oxygen sensor prolyl hydroxylase domain 2 (PHD2) plays an important role in cell hypoxia adaptation by regulating the stability of HIF proteins (HIF1α and HIF2α) in numerous cell types, including T lymphocytes. The role of oxygen sensor on immune cells, particularly on regulatory T cell (Treg) function, has not been fully elucidated. The purpose of our study was to evaluate the role of PHD2 in the regulation of Treg phenotype and function. We demonstrate herein that selective ablation of PHD2 expression in Treg (PHD2ΔTreg mice) leads to a spontaneous systemic inflammatory syndrome, as evidenced by weight loss, development of a rectal prolapse, splenomegaly, shortening of the colon, and elevated expression of IFN-γ in the mesenteric lymph nodes, intestine, and spleen. PHD2 deficiency in Tregs led to an increased number of activated CD4 conventional T cells expressing a Th1-like effector phenotype. Concomitantly, the expression of innate-type cytokines such as Il1b, Il12a, Il12b, and Tnfa was found to be elevated in peripheral (gut) tissues and spleen. PHD2ΔTreg mice also displayed an enhanced sensitivity to dextran sodium sulfate-induced colitis and toxoplasmosis, suggesting that PHD2-deficient Tregs did not efficiently control inflammatory response in vivo, particularly those characterized by IFN-γ production. Further analysis revealed that Treg dysregulation was largely prevented in PHD2-HIF2α (PHD2-HIF2αΔTreg mice), but not in PHD2-HIF1α (PHD2-HIF1αΔTreg mice) double KOs, suggesting an important and possibly selective role of the PHD2-HIF2α axis in the control of Treg function. Finally, the transcriptomic analysis of PHD2-deficient Tregs identified the STAT1 pathway as a target of the PHD2-HIF2α axis in regulatory T cell phenotype and in vivo function.
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Affiliation(s)
| | | | | | | | - Hind Hussein
- Université Libre de Bruxelles, Gosselies, Belgium
| | - Mohammad Krayem
- Department of Radiation Oncology, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Muriel Moser
- Université Libre de Bruxelles, Gosselies, Belgium
| | | | - Oberdan Leo
- Université Libre de Bruxelles, Gosselies, Belgium
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3
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Abstract
Oxygen (O2) is essential for life and therefore the supply of sufficient O2 to the tissues is a major physiological challenge. In mammals, a deficit of O2 (hypoxia) triggers rapid cardiorespiratory reflexes (e.g. hyperventilation and increased heart output) that within a few seconds increase the uptake of O2 by the lungs and its distribution throughout the body. The prototypical acute O2-sensing organ is the carotid body (CB), which contains sensory glomus cells expressing O2-regulated ion channels. In response to hypoxia, glomus cells depolarize and release transmitters which activate afferent fibers terminating at the brainstem respiratory and autonomic centers. In this review, we summarize the basic properties of CB chemoreceptor cells and the essential role played by their specialized mitochondria in acute O2 sensing and signaling. We focus on recent data supporting a "mitochondria-to-membrane signaling" model of CB chemosensory transduction. The possibility that the differential expression of specific subunit isoforms and enzymes could allow mitochondria to play a generalized adaptive O2-sensing and signaling role in a wide variety of cells is also discussed.
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Affiliation(s)
- José López-Barneo
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Patricia Ortega-Sáenz
- Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain.,Departamento de Fisiología Médica y Biofísica, Facultad de Medicina, Universidad de Sevilla, Seville, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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4
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Vasconcelos-Lima JL, Oikawa-Cardoso VL, Heinrichs-Caldas W, Almeida-Val VMF. Influence of hypoxia on biochemical aspects and on expression of genes related to oxygen-homeostasis of the Amazonian cichlid Astronotus ocellatus (Agassiz, 1831). Genet Mol Biol 2021; 44:e20210127. [PMID: 34807223 PMCID: PMC8607528 DOI: 10.1590/1678-4685-gmb-2021-0127] [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: 05/06/2021] [Accepted: 09/06/2021] [Indexed: 11/22/2022] Open
Abstract
Variations in dissolved oxygen levels are common in the Amazonian aquatic environments and the aquatic organisms that inhabit these environments developed a variety of adaptive responses to deal with such conditions. Some Amazonian fish species are tolerant to low oxygen levels and the cichlid Astronotus ocellatus is one of the most hypoxia-tolerant species. Herein, we aimed to unveil the biochemical and molecular responses that A. ocellatus presents when submitted to hypoxia. Hypoxia indicators were measured, such as plasma glucose, plasma lactate, hepatic glycogen and relative transcript levels of prolyl hydroxylase 2 (phd2) and hypoxia-inducible factor-1α (hif-1α) in juveniles of approximately 50 g exposed to 1, 3, and 5 hours of hypoxia (0.7 mg O2.L-1), followed by 3 hours of recovery in normoxia (6 mg O2.L-1). Fish exposed to hypoxia reduced liver glycogen levels within 3 hours of hypoxia, when comparing with 1 hour, and increased plasma glucose and lactate. Under the same condition, phd2 transcripts levels increased in gills, but decreased in liver. In contrast, hypoxia did not affect relative gene expression of hif-1α in both tissues. Based on the transcription pattern of phd2, these results showed that liver and gills of A. ocellatus have different molecular strategies to cope with environmental hypoxia.
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Affiliation(s)
- José L Vasconcelos-Lima
- Instituto Nacional de Pesquisas da Amazônia, Laboratório de Ecofisiologia e Evolução Molecular (LEEM), Manaus, AM, Brazil
| | - Vanessa L Oikawa-Cardoso
- Instituto Nacional de Pesquisas da Amazônia, Laboratório de Ecofisiologia e Evolução Molecular (LEEM), Manaus, AM, Brazil
| | - Waldir Heinrichs-Caldas
- Instituto Nacional de Pesquisas da Amazônia, Laboratório de Ecofisiologia e Evolução Molecular (LEEM), Manaus, AM, Brazil
| | - Vera M F Almeida-Val
- Instituto Nacional de Pesquisas da Amazônia, Laboratório de Ecofisiologia e Evolução Molecular (LEEM), Manaus, AM, Brazil
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5
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Belousov PV. Analysis of the Repertoires of Circulating Autoantibodies' Specificities as a Tool for Identification of the Tumor-Associated Antigens: Current Problems and Solutions. BIOCHEMISTRY. BIOKHIMIIA 2021; 86:1225-1242. [PMID: 34903148 DOI: 10.1134/s0006297921100060] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/17/2020] [Accepted: 08/24/2020] [Indexed: 06/14/2023]
Abstract
Circulating autoantibodies against tumor-associated autoantigens (TAA) may serve as valuable biomarkers for a wide range of diagnostic purposes. Modern immunology offers a large variety of methods for in-depth comparative analysis of the repertoires of circulating antibodies' antigenic specificities in health and disease. Nevertheless, this research field so far has met somewhat limited clinical success, while numerous data on the repertoires of circulating autoantibodies' specificities in cancer patients are poorly integrated into the contemporary picture of the immunological and molecular landscapes of human tumors. This review is an attempt to identify and systematize the key and essentially universal conceptual and methodological limitations of analyses of the repertoires of circulating antibodies' antigenic specificities in cancer (expression bias, redundancy of TAA repertoires, identification of natural IgG, the absence of the pathogenetically relevant context in the experimental systems used to detect TAA), as well as to discuss potential and already known methodological improvements that may significantly increase the detectability of the pathogenetically relevant and diagnostically significant bona fide TAA.
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Affiliation(s)
- Pavel V Belousov
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, 119991, Russia.
- National Center for Personalized Medicine of Endocrine Diseases, National Medical Research Center of Endocrinology, Ministry of Health of the Russian Federation, Moscow, 117036, Russia
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6
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Chen Y, Gaber T. Hypoxia/HIF Modulates Immune Responses. Biomedicines 2021; 9:biomedicines9030260. [PMID: 33808042 PMCID: PMC8000289 DOI: 10.3390/biomedicines9030260] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 02/07/2023] Open
Abstract
Oxygen availability varies throughout the human body in health and disease. Under physiological conditions, oxygen availability drops from the lungs over the blood stream towards the different tissues into the cells and the mitochondrial cavities leading to physiological low oxygen conditions or physiological hypoxia in all organs including primary lymphoid organs. Moreover, immune cells travel throughout the body searching for damaged cells and foreign antigens facing a variety of oxygen levels. Consequently, physiological hypoxia impacts immune cell function finally controlling innate and adaptive immune response mainly by transcriptional regulation via hypoxia-inducible factors (HIFs). Under pathophysiological conditions such as found in inflammation, injury, infection, ischemia and cancer, severe hypoxia can alter immune cells leading to dysfunctional immune response finally leading to tissue damage, cancer progression and autoimmunity. Here we summarize the effects of physiological and pathophysiological hypoxia on innate and adaptive immune activity, we provide an overview on the control of immune response by cellular hypoxia-induced pathways with focus on the role of HIFs and discuss the opportunity to target hypoxia-sensitive pathways for the treatment of cancer and autoimmunity.
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Affiliation(s)
- Yuling Chen
- Charité—Universitätsmedizin Berlin, Corporate Ember of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Rheumatology and Clinical Immunology, Charitéplatz 1, 10117 Berlin, Germany;
| | - Timo Gaber
- Charité—Universitätsmedizin Berlin, Corporate Ember of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Department of Rheumatology and Clinical Immunology, Charitéplatz 1, 10117 Berlin, Germany;
- German Rheumatism Research Centre (DRFZ) Berlin, a Leibniz Institute, Charitéplatz 1, 10117 Berlin, Germany
- Correspondence: ; Tel.: +49-30-450-513364
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7
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Itani OA, Zhong X, Tang X, Scott BA, Yan JY, Flibotte S, Lim Y, Hsieh AC, Bruce JE, Van Gilst M, Crowder CM. Coordinate Regulation of Ribosome and tRNA Biogenesis Controls Hypoxic Injury and Translation. Curr Biol 2020; 31:128-137.e5. [PMID: 33157031 DOI: 10.1016/j.cub.2020.10.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 08/21/2020] [Accepted: 10/01/2020] [Indexed: 01/01/2023]
Abstract
The translation machinery is composed of a myriad of proteins and RNAs whose levels must be coordinated to efficiently produce proteins without wasting energy or substrate. However, protein synthesis is clearly not always perfectly tuned to its environment, as disruption of translation machinery components can lengthen lifespan and stress survival. While much has been learned from bacteria and yeast about translational regulation, much less is known in metazoans. In a screen for mutations protecting C. elegans from hypoxic stress, we isolated multiple genes impacting protein synthesis: a ribosomal RNA helicase gene, tRNA biosynthesis genes, and a gene controlling amino acid availability. To define better the mechanisms by which these genes impact protein synthesis, we performed a second screen for suppressors of the conditional developmental arrest phenotype of the RNA helicase mutant and identified genes involved in ribosome biogenesis. Surprisingly, these suppressor mutations restored normal hypoxic sensitivity and protein synthesis to the tRNA biogenesis mutants, but not to the mutant reducing amino acid uptake. Proteomic analysis demonstrated that reduced tRNA biosynthetic activity produces a selective homeostatic reduction in ribosomal subunits, thereby offering a mechanism for the suppression results. Our study uncovers an unrecognized higher-order-translation regulatory mechanism in a metazoan whereby ribosome biogenesis genes communicate with genes controlling tRNA abundance matching the global rate of protein synthesis with available resources.
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Affiliation(s)
- Omar A Itani
- Department of Anesthesiology and Pain Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-6540, USA; Mitochondria and Metabolism Center, University of Washington, 850 Republican Street, Seattle, WA 98105, USA
| | - Xuefei Zhong
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA 98105, USA
| | - Xiaoting Tang
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA 98105, USA
| | - Barbara A Scott
- Department of Anesthesiology and Pain Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-6540, USA; Mitochondria and Metabolism Center, University of Washington, 850 Republican Street, Seattle, WA 98105, USA
| | - Jun Yi Yan
- Department of Anesthesiology and Pain Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-6540, USA; Mitochondria and Metabolism Center, University of Washington, 850 Republican Street, Seattle, WA 98105, USA; Department of Anesthesiology, Central Hospital of Changdian, Dandong, Liaoning 118214, China
| | - Stephane Flibotte
- Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall Vancouver, BC V6T 1Z3, Canada
| | - Yiting Lim
- Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N, Seattle, WA 98109, USA
| | - Andrew C Hsieh
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA 98105, USA; Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave. N, Seattle, WA 98109, USA; Department of Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-6420, USA
| | - James E Bruce
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA 98105, USA
| | - Marc Van Gilst
- Department of Anesthesiology and Pain Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-6540, USA; Mitochondria and Metabolism Center, University of Washington, 850 Republican Street, Seattle, WA 98105, USA
| | - C Michael Crowder
- Department of Anesthesiology and Pain Medicine, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195-6540, USA; Mitochondria and Metabolism Center, University of Washington, 850 Republican Street, Seattle, WA 98105, USA; Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA 98105, USA.
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8
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Lee P, Chandel NS, Simon MC. Cellular adaptation to hypoxia through hypoxia inducible factors and beyond. Nat Rev Mol Cell Biol 2020; 21:268-283. [PMID: 32144406 PMCID: PMC7222024 DOI: 10.1038/s41580-020-0227-y] [Citation(s) in RCA: 606] [Impact Index Per Article: 151.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2020] [Indexed: 02/06/2023]
Abstract
Molecular oxygen (O2) sustains intracellular bioenergetics and is consumed by numerous biochemical reactions, making it essential for most species on Earth. Accordingly, decreased oxygen concentration (hypoxia) is a major stressor that generally subverts life of aerobic species and is a prominent feature of pathological states encountered in bacterial infection, inflammation, wounds, cardiovascular defects and cancer. Therefore, key adaptive mechanisms to cope with hypoxia have evolved in mammals. Systemically, these adaptations include increased ventilation, cardiac output, blood vessel growth and circulating red blood cell numbers. On a cellular level, ATP-consuming reactions are suppressed, and metabolism is altered until oxygen homeostasis is restored. A critical question is how mammalian cells sense oxygen levels to coordinate diverse biological outputs during hypoxia. The best-studied mechanism of response to hypoxia involves hypoxia inducible factors (HIFs), which are stabilized by low oxygen availability and control the expression of a multitude of genes, including those involved in cell survival, angiogenesis, glycolysis and invasion/metastasis. Importantly, changes in oxygen can also be sensed via other stress pathways as well as changes in metabolite levels and the generation of reactive oxygen species by mitochondria. Collectively, this leads to cellular adaptations of protein synthesis, energy metabolism, mitochondrial respiration, lipid and carbon metabolism as well as nutrient acquisition. These mechanisms are integral inputs into fine-tuning the responses to hypoxic stress.
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Affiliation(s)
- Pearl Lee
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
| | - Navdeep S Chandel
- Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
- Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
| | - M Celeste Simon
- Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
- Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA.
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9
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Abstract
Cells respond to hypoxia by shifting cellular processes from general housekeeping functions to activating specialized hypoxia-response pathways. Oxygen plays an important role in generating ATP to maintain a productive rate of protein synthesis in normoxia. In hypoxia, the rate of the canonical protein synthesis pathway is significantly slowed and impaired due to limited ATP availability, necessitating an alternative mechanism to mediate protein synthesis and facilitate adaptation. Hypoxia adaptation is largely mediated by hypoxia-inducible factors (HIFs). While HIFs are well known for their transcriptional functions, they also play imperative roles in translation to mediate hypoxic protein synthesis. Such adaptations to hypoxia are often hyperactive in solid tumors, contributing to the expression of cancer hallmarks, including treatment resistance. The current literature on protein synthesis in hypoxia is reviewed here, inclusive of hypoxia-specific mRNA selection to translation termination. Current HIF targeting therapies are also discussed as are the opportunities involved with targeting hypoxia specific protein synthesis pathways.
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Affiliation(s)
- Nancy T Chee
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Avenue, Miami, FL, 33136, USA
| | - Ines Lohse
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Avenue, Miami, FL, 33136, USA
| | - Shaun P Brothers
- Department of Psychiatry and Behavioral Sciences, University of Miami Miller School of Medicine, 1501 NW 10th Avenue, Miami, FL, 33136, USA.
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10
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Florimond C, Cordonnier C, Taujale R, van der Wel H, Kannan N, West CM, Blader IJ. A Toxoplasma Prolyl Hydroxylase Mediates Oxygen Stress Responses by Regulating Translation Elongation. mBio 2019; 10:e00234-19. [PMID: 30914506 PMCID: PMC6437050 DOI: 10.1128/mbio.00234-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 02/08/2019] [Indexed: 02/08/2023] Open
Abstract
As the protozoan parasite Toxoplasma gondii disseminates through its host, it responds to environmental changes by altering its gene expression, metabolism, and other processes. Oxygen is one variable environmental factor, and properly adapting to changes in oxygen levels is critical to prevent the accumulation of reactive oxygen species and other cytotoxic factors. Thus, oxygen-sensing proteins are important, and among these, 2-oxoglutarate-dependent prolyl hydroxylases are highly conserved throughout evolution. Toxoplasma expresses two such enzymes, TgPHYa, which regulates the SCF-ubiquitin ligase complex, and TgPHYb. To characterize TgPHYb, we created a Toxoplasma strain that conditionally expresses TgPHYb and report that TgPHYb is required for optimal parasite growth under normal growth conditions. However, exposing TgPHYb-depleted parasites to extracellular stress leads to severe decreases in parasite invasion, which is likely due to decreased abundance of parasite adhesins. Adhesin protein abundance is reduced in TgPHYb-depleted parasites as a result of inactivation of the protein synthesis elongation factor eEF2 that is accompanied by decreased rates of translational elongation. In contrast to most other oxygen-sensing proteins that mediate cellular responses to low O2, TgPHYb is specifically required for parasite growth and protein synthesis at high, but not low, O2 tensions as well as resistance to reactive oxygen species. In vivo, reduced TgPHYb expression leads to lower parasite burdens in oxygen-rich tissues. Taken together, these data identify TgPHYb as a sensor of high O2 levels, in contrast to TgPHYa, which supports the parasite at low O2IMPORTANCE Because oxygen plays a key role in the growth of many organisms, cells must know how much oxygen is available. O2-sensing proteins are therefore critical cellular factors, and prolyl hydroxylases are the best-studied type of O2-sensing proteins. In general, prolyl hydroxylases trigger cellular responses to decreased oxygen availability. But, how does a cell react to high levels of oxygen? Using the protozoan parasite Toxoplasma gondii, we discovered a prolyl hydroxylase that allows the parasite to grow at elevated oxygen levels and does so by regulating protein synthesis. Loss of this enzyme also reduces parasite burden in oxygen-rich tissues, indicating that sensing both high and low levels of oxygen impacts the growth and physiology of Toxoplasma.
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Affiliation(s)
- Celia Florimond
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, USA
| | - Charlotte Cordonnier
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, USA
| | - Rahil Taujale
- Institute of Bioinformatics, University of Georgia, Athens, Georgia, USA
| | - Hanke van der Wel
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Natarajan Kannan
- Institute of Bioinformatics, University of Georgia, Athens, Georgia, USA
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
| | - Christopher M West
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia, USA
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Ira J Blader
- Department of Microbiology and Immunology, University at Buffalo School of Medicine, Buffalo, New York, USA
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11
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Li A, Zhang Y, Wang Z, Dong H, Fu N, Han X. The roles and signaling pathways of prolyl-4-hydroxylase 2 in the tumor microenvironment. Chem Biol Interact 2019; 303:40-49. [PMID: 30817904 DOI: 10.1016/j.cbi.2019.02.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 02/16/2019] [Accepted: 02/19/2019] [Indexed: 02/06/2023]
Abstract
Tumor hypoxia is a well-known microenvironmental factor that causes cancer progression and resistance to cancer treatment. Proline hydroxylases (PHDs), a small protein family, belong to an evolutionarily conserved superfamily of dioxygenases, considered the central regulator of the molecular hypoxia response. Prolyl-4-hydroxylase 2 (PHD2), one member of PHDs family, regulates the stability of the hypoxia-inducible factor-1 alpha (HIF-1α) in response to oxygen availability. During hypoxia, the inhibition of PHD2 permits the accumulation of HIF-1α, allowing the cellular adaptation to oxygen limitation, causing activation of numerous genes, which enhances the angiogenesis, metastasis and invasiveness. Accurate regulation of oxygen homeostasis is essential, and which implies PHD2 may have a regulatory role in the pathogenesis of cancer. Although ample evidence exists for a positive correlation between HIFs and tumor formation, metastasis and poor prognosis, the function of the PHD2 in carcinogenesis is less well understood. Despite their original role as the oxygen sensors of the cell and many of the its functions are clearly conveyed through the HIF system, PHD2 is currently known to display HIF-independent and hydroxylase-independent functions in cancer cells and stroma in the control of different cellular pathways. In this review, we summarize the recent advances in the structure, regulation and functions of PHD2 in cancer microenvironment.
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Affiliation(s)
- Anqi Li
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Yu Zhang
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Zuojun Wang
- Department of Pharmacy, Linqu Country People's Hospital, 438 Shanwang Road, Linqu, 262600, China
| | - Hailing Dong
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Nange Fu
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China
| | - Xiuzhen Han
- Department of Pharmacology, School of Pharmaceutical Sciences, Shandong University, 44 West Wenhua Road, Jinan, 250012, China.
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12
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Schnicker NJ, Razzaghi M, Guha Thakurta S, Chakravarthy S, Dey M. Bacillus anthracis Prolyl 4-Hydroxylase Interacts with and Modifies Elongation Factor Tu. Biochemistry 2017; 56:5771-5785. [PMID: 28981257 DOI: 10.1021/acs.biochem.7b00601] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Prolyl hydroxylation is a very common post-translational modification and plays many roles in eukaryotes such as collagen stabilization, hypoxia sensing, and controlling protein transcription and translation. There is a growing body of evidence that suggests that prokaryotes contain prolyl 4-hydroxylases (P4Hs) homologous to the hypoxia-inducible factor (HIF) prolyl hydroxylase domain (PHD) enzymes that act on elongation factor Tu (EFTu) and are likely involved in the regulation of bacterial translation. Recent biochemical and structural studies with a PHD from Pseudomonas putida (PPHD) determined that it forms a complex with EFTu and hydroxylates a prolyl residue of EFTu. Moreover, while animal, plant, and viral P4Hs act on peptidyl proline, most prokaryotic P4Hs have been known to target free l-proline; the exceptions include PPHD and a P4H from Bacillus anthracis (BaP4H) that modifies collagen-like proline-rich peptides. Here we use biophysical and mass spectrometric methods to demonstrate that BaP4H recognizes full-length BaEFTu and a BaEFTu 9-mer peptide for site-specific proline hydroxylation. Using size-exclusion chromatography coupled small-angle X-ray scattering (SEC-SAXS) and binding studies, we determined that BaP4H forms a 1:1 heterodimeric complex with BaEFTu. The SEC-SAXS studies reveal dissociation of BaP4H dimeric subunits upon interaction with BaEFTu. While BaP4H is unusual within bacteria in that it is structurally and functionally similar to the animal PHDs and collagen P4Hs, respectively, this work provides further evidence of its promiscuous substrate recognition. It is possible that the enzyme might have evolved to hydroxylate a universally conserved protein in prokaryotes, similar to the PHDs, and implies a functional role in B. anthracis.
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Affiliation(s)
- Nicholas J Schnicker
- Department of Chemistry, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Mortezaali Razzaghi
- Department of Chemistry, The University of Iowa , Iowa City, Iowa 52242, United States
| | - Sanjukta Guha Thakurta
- Department of Cell Biology, Harvard Medical School , 240 Longwood Avenue, Boston, Massachusetts 02115, United States
| | - Srinivas Chakravarthy
- Biophysics Collaborative Access Team, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Mishtu Dey
- Department of Chemistry, The University of Iowa , Iowa City, Iowa 52242, United States
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13
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Fliedner SMJ, Shankavaram U, Marzouca G, Elkahloun A, Jochmanova I, Daerr R, Linehan WM, Timmers H, Tischler AS, Papaspyrou K, Brieger J, de Krijger R, Breza J, Eisenhofer G, Zhuang Z, Lehnert H, Pacak K. Hypoxia-Inducible Factor 2α Mutation-Related Paragangliomas Classify as Discrete Pseudohypoxic Subcluster. Neoplasia 2017; 18:567-76. [PMID: 27659016 PMCID: PMC5031903 DOI: 10.1016/j.neo.2016.07.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 07/22/2016] [Accepted: 07/25/2016] [Indexed: 01/06/2023] Open
Abstract
Recently, activating mutations of the hypoxia-inducible factor 2α gene (HIF2A/EPAS1) have been recognized to predispose to multiple paragangliomas (PGLs) and duodenal somatostatinomas associated with polycythemia, and ocular abnormalities. Previously, mutations in the SDHA/B/C/D, SDHAF2, VHL, FH, PHD1, and PHD2 genes have been associated with HIF activation and the development of pseudohypoxic (cluster-1) PGLs. These tumors overlap in terms of tumor location, syndromic presentation, and noradrenergic phenotype to a certain extent. However, they also differ especially by clinical outcome and by presence of other tumors or abnormalities. In the present study, we aimed to establish additional molecular differences between HIF2A and non-HIF2A pseudohypoxic PGLs. RNA expression patterns of HIF2A PGLs (n = 6) from 2 patients were compared with normal adrenal medullas (n = 8) and other hereditary pseudohypoxic PGLs (VHL: n = 13, SDHB: n = 15, and SDHD: n = 14). Unsupervised hierarchical clustering showed that HIF2A PGLs made up a separate cluster from other pseudohypoxic PGLs. Significance analysis of microarray yielded 875 differentially expressed genes between HIF2A and other pseudohypoxic PGLs after normalization to adrenal medulla (false discovery rate 0.01). Prediction analysis of microarray allowed correct classification of all HIF2A samples based on as little as three genes (TRHDE, LRRC63, IGSF10; error rate: 0.02). Genes with the highest expression difference between normal medulla and HIF2A PGLs were selected for confirmatory quantitative reverse transcriptase polymerase chain reaction. In conclusion, HIF2A PGLs show a characteristic expression signature that separates them from non-HIF2A pseudohypoxic PGLs. Unexpectedly, the most significantly differentially expressed genes have not been previously described as HIF target genes.
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Affiliation(s)
- Stephanie M J Fliedner
- 1st Department of Medicine, University Medical Center Schleswig-Holstein, Campus Lübeck, Lübeck, Germany; Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
| | - Uma Shankavaram
- Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Geena Marzouca
- Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Abdel Elkahloun
- Cancer Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Ivana Jochmanova
- Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; 1st Department of Internal Medicine Medical Faculty of P. J. Šafárik University in Košice, Košice, Slovakia
| | - Roland Daerr
- Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA; Institute of Clinical Chemistry & Laboratory Medicine and Department of Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - W Marston Linehan
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Henri Timmers
- Department of Internal Medicine, Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | - Konstantinos Papaspyrou
- Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jürgen Brieger
- Department of Otorhinolaryngology, Head and Neck Surgery, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Ronald de Krijger
- Department of Pathology, Josephine Nefkens Institute, Erasmus MC-University Medical Center, Rotterdam, The Netherlands; Department of Pathology, Reinier de Graaf Hospital, Delft, The Netherlands
| | - Jan Breza
- Department of Urology, Comenius University, Bratislava, Slovak Republic
| | - Graeme Eisenhofer
- Institute of Clinical Chemistry & Laboratory Medicine and Department of Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Zhengping Zhuang
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Hendrik Lehnert
- 1st Department of Medicine, University Medical Center Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Karel Pacak
- Section of Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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Binelli A, Del Giacco L, Santo N, Bini L, Magni S, Parolini M, Madaschi L, Ghilardi A, Maggioni D, Ascagni M, Armini A, Prosperi L, Landi C, La Porta C, Della Torre C. Carbon nanopowder acts as a Trojan-horse for benzo(α)pyrene in Danio rerio embryos. Nanotoxicology 2017; 11:371-381. [DOI: 10.1080/17435390.2017.1306130] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- A. Binelli
- Department of Biosciences, University of Milan, Milan, Italy
| | - L. Del Giacco
- Department of Biosciences, University of Milan, Milan, Italy
| | - N. Santo
- Department of Biosciences, University of Milan, Milan, Italy
| | - L. Bini
- Department of Life Science, University of Siena, Siena, Italy
| | - S. Magni
- Department of Biosciences, University of Milan, Milan, Italy
| | - M. Parolini
- Department of Biosciences, University of Milan, Milan, Italy
| | - L. Madaschi
- Department of Biosciences, University of Milan, Milan, Italy
| | - A. Ghilardi
- Department of Biosciences, University of Milan, Milan, Italy
| | - D. Maggioni
- Department of Chemistry, University of Milan, Milan, Italy
| | - M. Ascagni
- Department of Biosciences, University of Milan, Milan, Italy
| | - A. Armini
- Department of Life Science, University of Siena, Siena, Italy
| | - L. Prosperi
- Department of Biosciences, University of Milan, Milan, Italy
| | - C. Landi
- Department of Life Science, University of Siena, Siena, Italy
| | - C. La Porta
- Department of Biosciences, University of Milan, Milan, Italy
| | - C. Della Torre
- Department of Biosciences, University of Milan, Milan, Italy
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15
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Abstract
Oxygen represents one of the major molecules required for the development and maintenance of life. An adequate response to hypoxia is therefore required for the functioning of the majority of living organisms and relies on the activation of the hypoxia-inducible factor (HIF) pathway. HIF prolyl hydroxylase domain-2 (PHD2) has long been recognized as the major regulator of this response, controlling a myriad of outcomes that range from cell death to proliferation. However, this enzyme has been associated with more pathways, making the role of this protein remarkably complex under distinct pathologies. While a protective role seems to exist in physiological conditions such as erythropoiesis; the picture is more complex during pathologies such as cancer. Since the regulation of this enzyme and its closest family members is currently considered as a possible therapy for various diseases, understanding the different particular roles of this protein is essential.
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Affiliation(s)
- Ana M Meneses
- Heisenberg Research Group, Department of Clinical Pathobiochemistry, Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
| | - Ben Wielockx
- Heisenberg Research Group, Department of Clinical Pathobiochemistry, Institute for Clinical Chemistry and Laboratory Medicine, Technische Universität Dresden, Dresden, Germany
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16
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Dynamics of elongation factor 2 kinase regulation in cortical neurons in response to synaptic activity. J Neurosci 2015; 35:3034-47. [PMID: 25698741 DOI: 10.1523/jneurosci.2866-14.2015] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The rapid regulation of cell signaling in response to calcium in neurons is essential for real-time processing of large amounts of information in the brain. A vital regulatory component, and one of the most energy-intensive biochemical processes in cells, is the elongation phase of mRNA translation, which is controlled by the Ca(2+)/CaM-dependent elongation factor 2 kinase (eEF2K). However, little is known about the dynamics of eEF2K regulation in neurons despite its established role in learning and synaptic plasticity. To explore eEF2K dynamics in depth, we stimulated synaptic activity in mouse primary cortical neurons. We find that synaptic activity results in a rapid, but transient, increase in eEF2K activity that is regulated by a combination of AMPA and NMDA-type glutamate receptors and the mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) and mammalian target of rapamycin complex 1 (mTORC1) pathways. We then used computational modeling to test the hypothesis that considering Ca(2+)-coordinated MEK/ERK, mTORC1, and eEF2k activation is sufficient to describe the observed eEF2K dynamics. Although such a model could partially fit the empirical findings, it also suggested that a crucial positive regulator of eEF2K was also necessary. Through additional modeling and empirical evidence, we demonstrate that AMP kinase (AMPK) is also an important regulator of synaptic activity-driven eEF2K dynamics in neurons. Our combined modeling and experimental findings provide the first evidence that it is necessary to consider the combined interactions of Ca(2+) with MEK/ERK, mTORC1, and AMPK to adequately explain eEF2K regulation in neurons.
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17
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Elongation Factor 2 Kinase Is Regulated by Proline Hydroxylation and Protects Cells during Hypoxia. Mol Cell Biol 2015; 35:1788-804. [PMID: 25755286 DOI: 10.1128/mcb.01457-14] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/01/2015] [Indexed: 12/19/2022] Open
Abstract
Protein synthesis, especially translation elongation, requires large amounts of energy, which is often generated by oxidative metabolism. Elongation is controlled by phosphorylation of eukaryotic elongation factor 2 (eEF2), which inhibits its activity and is catalyzed by eEF2 kinase (eEF2K), a calcium/calmodulin-dependent α-kinase. Hypoxia causes the activation of eEF2K and induces eEF2 phosphorylation independently of previously known inputs into eEF2K. Here, we show that eEF2K is subject to hydroxylation on proline-98. Proline hydroxylation is catalyzed by proline hydroxylases, oxygen-dependent enzymes which are inactivated during hypoxia. Pharmacological inhibition of proline hydroxylases also stimulates eEF2 phosphorylation. Pro98 lies in a universally conserved linker between the calmodulin-binding and catalytic domains of eEF2K. Its hydroxylation partially impairs the binding of calmodulin to eEF2K and markedly limits the calmodulin-stimulated activity of eEF2K. Neuronal cells depend on oxygen, and eEF2K helps to protect them from hypoxia. eEF2K is the first example of a protein directly involved in a major energy-consuming process to be regulated by proline hydroxylation. Since eEF2K is cytoprotective during hypoxia and other conditions of nutrient insufficiency, it may be a valuable target for therapy of poorly vascularized solid tumors.
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18
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Zhuang Q, Feng T, Coleman ML. Modifying the maker: Oxygenases target ribosome biology. ACTA ACUST UNITED AC 2015; 3:e1009331. [PMID: 26779412 PMCID: PMC4682802 DOI: 10.1080/21690731.2015.1009331] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 01/14/2014] [Accepted: 01/15/2014] [Indexed: 01/05/2023]
Abstract
The complexity of the eukaryotic protein synthesis machinery is partly driven by extensive and diverse modifications to associated proteins and RNAs. These modifications can have important roles in regulating translation factor activity and ribosome biogenesis and function. Further investigation of ‘translational modifications’ is warranted considering the growing evidence implicating protein synthesis as a critical point of gene expression control that is commonly deregulated in disease. New evidence suggests that translation is a major new target for oxidative modifications, specifically hydroxylations and demethylations, which generally are catalyzed by a family of emerging oxygenase enzymes that act at the interface of nutrient availability and metabolism. This review summarizes what is currently known about the role or these enzymes in targeting rRNA synthesis, protein translation and associated cellular processes.
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Affiliation(s)
- Qinqin Zhuang
- Tumour Oxygenase Group; School of Cancer Sciences ; University of Birmingham ; Birmingham, UK
| | - Tianshu Feng
- Centre for Cellular and Molecular Physiology; University of Oxford ; Oxford, UK
| | - Mathew L Coleman
- Tumour Oxygenase Group; School of Cancer Sciences ; University of Birmingham ; Birmingham, UK
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19
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Levett DZH, Viganò A, Capitanio D, Vasso M, De Palma S, Moriggi M, Martin DS, Murray AJ, Cerretelli P, Grocott MPW, Gelfi C. Changes in muscle proteomics in the course of the Caudwell Research Expedition to Mt. Everest. Proteomics 2014; 15:160-71. [DOI: 10.1002/pmic.201400306] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/16/2014] [Accepted: 10/10/2014] [Indexed: 12/27/2022]
Affiliation(s)
- Denny Z. H. Levett
- Centre for Altitude, Space, and Extreme Environment Medicine; University College London (UCL); Institute of Child Health; University College London; London UK
- Anaesthesia and Critical Care Research Unit; University Hospital Southampton; NHS Foundation Trust; Southampton UK
| | - Agnese Viganò
- Department of Biomedical Sciences for Health; University of Milan; Segrate Milan Italy
| | - Daniele Capitanio
- Department of Biomedical Sciences for Health; University of Milan; Segrate Milan Italy
- IRCCS Policlinico San Donato; San Donato Milanese Milano Italy
| | - Michele Vasso
- CNR-Institute of Bioimaging and Molecular Physiology; Cefalù-Segrate Italy
| | - Sara De Palma
- CNR-Institute of Bioimaging and Molecular Physiology; Cefalù-Segrate Italy
| | - Manuela Moriggi
- Department of Biomedical Sciences for Health; University of Milan; Segrate Milan Italy
- IRCCS Policlinico San Donato; San Donato Milanese Milano Italy
| | - Daniel S. Martin
- Centre for Altitude, Space, and Extreme Environment Medicine; University College London (UCL); Institute of Child Health; University College London; London UK
| | - Andrew J. Murray
- Department of Physiology; Development, and Neuroscience; University of Cambridge; Cambridge UK
| | - Paolo Cerretelli
- CNR-Institute of Bioimaging and Molecular Physiology; Cefalù-Segrate Italy
| | - Mike P. W. Grocott
- Anaesthesia and Critical Care Research Unit; University Hospital Southampton; NHS Foundation Trust; Southampton UK
- Integrative Physiology and Critical Illness Group; Division of Clinical and Experimental Science; Faculty of Medicine, University of Southampton; Southampton UK
- Southampton NIHR Respiratory Biomedical Research Unit; Southampton UK
| | - Cecilia Gelfi
- Department of Biomedical Sciences for Health; University of Milan; Segrate Milan Italy
- IRCCS Policlinico San Donato; San Donato Milanese Milano Italy
- CNR-Institute of Bioimaging and Molecular Physiology; Cefalù-Segrate Italy
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20
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Leprivier G, Rotblat B, Khan D, Jan E, Sorensen PH. Stress-mediated translational control in cancer cells. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:845-60. [PMID: 25464034 DOI: 10.1016/j.bbagrm.2014.11.002] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 10/31/2014] [Accepted: 11/04/2014] [Indexed: 12/22/2022]
Abstract
Tumor cells are continually subjected to diverse stress conditions of the tumor microenvironment, including hypoxia, nutrient deprivation, and oxidative or genotoxic stress. Tumor cells must evolve adaptive mechanisms to survive these conditions to ultimately drive tumor progression. Tight control of mRNA translation is critical for this response and the adaptation of tumor cells to such stress forms. This proceeds though a translational reprogramming process which restrains overall translation activity to preserve energy and nutrients, but which also stimulates the selective synthesis of major stress adaptor proteins. Here we present the different regulatory signaling pathways which coordinate mRNA translation in the response to different stress forms, including those regulating eIF2α, mTORC1 and eEF2K, and we explain how tumor cells hijack these pathways for survival under stress. Finally, mechanisms for selective mRNA translation under stress, including the utilization of upstream open reading frames (uORFs) and internal ribosome entry sites (IRESes) are discussed in the context of cell stress. This article is part of a Special Issue entitled: Translation and Cancer.
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Affiliation(s)
- Gabriel Leprivier
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, British Columbia V5Z 1L4, Canada; Department of Pathology, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada
| | - Barak Rotblat
- Department of Life Science, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Debjit Khan
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, British Columbia V5Z 1L4, Canada; Department of Pathology, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada
| | - Eric Jan
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia V6T1Z3, Canada
| | - Poul H Sorensen
- Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, British Columbia V5Z 1L4, Canada; Department of Pathology, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada.
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21
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Núñez-O'Mara A, Gerpe-Pita A, Pozo S, Carlevaris O, Urzelai B, Lopitz-Otsoa F, Rodríguez MS, Berra E. PHD3-SUMO conjugation represses HIF1 transcriptional activity independently of PHD3 catalytic activity. J Cell Sci 2014; 128:40-9. [PMID: 25380826 DOI: 10.1242/jcs.151514] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
By controlling HIFα hydroxylation and stability, the prolyl hydroxylase domain (PHD)-containing proteins are essential to the maintenance of oxygen homeostasis; therefore these enzymes are tightly regulated. Small ubiquitin-like modifier (SUMO) is a 10-kDa protein readily conjugated to lysine residues of the targeted proteins in a process termed SUMOylation. In this study, we introduce SUMO conjugation as a novel regulator of PHD3 (also known as EGLN3). PHD3 SUMOylation occurs at a cluster of four lysines at the C-terminal end of the protein. Furthermore, PHD3 SUMOylation by SUMO2 or SUMO3 contributes to PHD3-mediated repression of HIF1-dependent transcriptional activity. Interestingly, PHD3-SUMO conjugation does not affect PHD3 hydroxylase activity or HIF1α stability, providing new evidence for a dual role of PHD3 in HIF1 regulation. Moreover, we show that hypoxia modulates PHD3-SUMO conjugation and that this modification inversely correlates with HIF1 activation. PHD3 SUMOylation highlights a new and additional layer of regulation that is likely required to fine-tune HIF function.
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Affiliation(s)
- Analía Núñez-O'Mara
- Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain
| | - Almudena Gerpe-Pita
- Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain
| | - Sara Pozo
- Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain
| | - Onintza Carlevaris
- Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain
| | - Bakarne Urzelai
- Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain
| | - Fernando Lopitz-Otsoa
- Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain
| | - Manuel S Rodríguez
- Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain
| | - Edurne Berra
- Centro de Investigación Cooperativa en Biociencias-CIC bioGUNE, Parque Tecnológico de Bizkaia, Ed. 801A, 48190 Derio, Spain
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22
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Scotti JS, Leung IKH, Ge W, Bentley MA, Paps J, Kramer HB, Lee J, Aik W, Choi H, Paulsen SM, Bowman LAH, Loik ND, Horita S, Ho CH, Kershaw NJ, Tang CM, Claridge TDW, Preston GM, McDonough MA, Schofield CJ. Human oxygen sensing may have origins in prokaryotic elongation factor Tu prolyl-hydroxylation. Proc Natl Acad Sci U S A 2014; 111:13331-6. [PMID: 25197067 PMCID: PMC4169948 DOI: 10.1073/pnas.1409916111] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The roles of 2-oxoglutarate (2OG)-dependent prolyl-hydroxylases in eukaryotes include collagen stabilization, hypoxia sensing, and translational regulation. The hypoxia-inducible factor (HIF) sensing system is conserved in animals, but not in other organisms. However, bioinformatics imply that 2OG-dependent prolyl-hydroxylases (PHDs) homologous to those acting as sensing components for the HIF system in animals occur in prokaryotes. We report cellular, biochemical, and crystallographic analyses revealing that Pseudomonas prolyl-hydroxylase domain containing protein (PPHD) contain a 2OG oxygenase related in structure and function to the animal PHDs. A Pseudomonas aeruginosa PPHD knockout mutant displays impaired growth in the presence of iron chelators and increased production of the virulence factor pyocyanin. We identify elongation factor Tu (EF-Tu) as a PPHD substrate, which undergoes prolyl-4-hydroxylation on its switch I loop. A crystal structure of PPHD reveals striking similarity to human PHD2 and a Chlamydomonas reinhardtii prolyl-4-hydroxylase. A crystal structure of PPHD complexed with intact EF-Tu reveals that major conformational changes occur in both PPHD and EF-Tu, including a >20-Å movement of the EF-Tu switch I loop. Comparison of the PPHD structures with those of HIF and collagen PHDs reveals conservation in substrate recognition despite diverse biological roles and origins. The observed changes will be useful in designing new types of 2OG oxygenase inhibitors based on various conformational states, rather than active site iron chelators, which make up most reported 2OG oxygenase inhibitors. Structurally informed phylogenetic analyses suggest that the role of prolyl-hydroxylation in human hypoxia sensing has ancient origins.
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Affiliation(s)
- John S Scotti
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Ivanhoe K H Leung
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Wei Ge
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom; Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Michael A Bentley
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom
| | - Jordi Paps
- Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
| | - Holger B Kramer
- Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford OX1 3QX, United Kingdom; and
| | - Joongoo Lee
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - WeiShen Aik
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Hwanho Choi
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Steinar M Paulsen
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom
| | - Lesley A H Bowman
- Department of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Nikita D Loik
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Shoichiro Horita
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom; Department of Physiology, Anatomy, and Genetics, University of Oxford, Oxford OX1 3QX, United Kingdom; and
| | - Chia-hua Ho
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Nadia J Kershaw
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Christoph M Tang
- Department of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
| | - Timothy D W Claridge
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Gail M Preston
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom
| | - Michael A McDonough
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom
| | - Christopher J Schofield
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3TA, United Kingdom;
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23
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Bandara V, Michael MZ, Gleadle JM. Hypoxia represses microRNA biogenesis proteins in breast cancer cells. BMC Cancer 2014; 14:533. [PMID: 25052766 PMCID: PMC4223767 DOI: 10.1186/1471-2407-14-533] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 07/16/2014] [Indexed: 02/08/2023] Open
Abstract
Background Cancers are commonly characterised by hypoxia and also by global reductions in the levels of mature microRNAs. We have examined the hypothesis that hypoxia might mediate this reduction through repressive effects on microRNA biogenesis proteins. Methods Breast cancer cell lines were exposed to hypoxia and manipulations of hypoxia inducible factor (HIF) and HIF hydroxylase activity. The effects of hypoxia on the mRNA and protein levels of enzymes involved in microRNA biogenesis (Dicer, Drosha, TARPB2, DCGR8, XPO5) was determined by RT PCR and immunoblotting. The effect of hypoxia on microRNAs was determined with microarray studies, RT PCR and reporter assays. Results In breast cancer lines there was significant reduction of Dicer mRNA and protein levels in cells exposed to hypoxia. This effect was independent of HIF but dependent on the HIF hydroxylase PHD2 and was partly mediated by feedback effects via microRNAs. Furthermore, several other proteins with critical roles in microRNA biogenesis (Drosha, TARBP2 and DCGR8) also showed significant and co-ordinated repression under hypoxic conditions. Despite these substantial alterations no, or modest, changes were observed in mature microRNA production. Conclusion These observations provide further and important interfaces between oxygen availability and gene expression and a potential mechanistic explanation for the reduced levels of microRNAs observed in some cancers. They provide further support for the existence of feedback mechanisms in the regulation of the microRNA biogenesis pathway and the relative stability of microRNAs.
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Affiliation(s)
| | | | - Jonathan M Gleadle
- Renal Department, Flinders Medical Centre, Flinders University School of Medicine, Bedford Park, Adelaide, South Australia 5042, Australia.
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24
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Kenney JW, Moore CE, Wang X, Proud CG. Eukaryotic elongation factor 2 kinase, an unusual enzyme with multiple roles. Adv Biol Regul 2014; 55:15-27. [PMID: 24853390 DOI: 10.1016/j.jbior.2014.04.003] [Citation(s) in RCA: 132] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 04/15/2014] [Indexed: 12/27/2022]
Abstract
Eukaryotic elongation factor 2 kinase (eEF2K) is a member of the small group of atypical 'α-kinases'. It phosphorylates and inhibits eukaryotic elongation factor 2, to slow down the elongation stage of protein synthesis, which normally consumes a great deal of energy and amino acids. The activity of eEF2K is normally dependent on calcium ions and calmodulin. eEF2K is also regulated by a plethora of other inputs, including inhibition by signalling downstream of anabolic signalling pathways such as the mammalian target of rapamycin complex 1. Recent data show that eEF2K helps to protect cancer cells against nutrient starvation and is also cytoprotective in other settings, including hypoxia. Growing evidence points to roles for eEF2K in neurological processes such as learning and memory and perhaps in depression.
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Affiliation(s)
- Justin W Kenney
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, SO16 7LB, UK
| | - Claire E Moore
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, SO16 7LB, UK
| | - Xuemin Wang
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, SO16 7LB, UK
| | - Christopher G Proud
- Centre for Biological Sciences, Life Sciences Building, University of Southampton, Southampton, SO16 7LB, UK.
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25
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Tan HY, Wang N, Tsao SW, Zhang Z, Feng Y. Suppression of vascular endothelial growth factor via inactivation of eukaryotic elongation factor 2 by alkaloids in Coptidis rhizome in hepatocellular carcinoma. Integr Cancer Ther 2013; 13:425-34. [PMID: 24363282 DOI: 10.1177/1534735413513635] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
AIM OF STUDY To investigate the inhibitory effect of Coptidis rhizome aqueous extract (CRAE) on vascular endothelial growth factor (VEGF) expression and tumor angiogenesis in hepatocellular carcinoma (HCC). METHODS Quality control of CRAE was determined. Secretion of VEGF protein and expression of its mRNA in MHCC97L and Hep G2 cells were measured with enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction. Synthesis of nascent protein was determined by AHA-protein-labeling technologies. The in vivo antiangiogenic effect of CRAE was evaluated with a xenograft model. RESULTS Absence of organochlorine pesticides in CRAE was found, and phytochemical analysis showed that its components were in proportion of magnoflorine 2.2%, jatrorrhizine 1.68%, palmatine 4.4%, and berberine 13.8%. CRAE exhibited significant inhibition on VEGF secretion from MHCC97L and HepG2 cells at nontoxic doses. The mRNA transcripts of VEGF could not be inhibited by CRAE; however, synthesis of VEGF nascent protein was potently blocked by CRAE. CRAE intervention increased the phosphorylation of eukaryotic elongation factor 2 (eEF2) in HCC cells, which blocked eEF2 activity for proceeding nascent protein synthesis. The activity of eEF2 was restored in CRAE-treated HCC cells in the presence of A484594, leading to the recovery of VEGF expression. Berberine was found to be the major active component in CRAE; however, CRAE is more effective in inhibiting eEF2 activity compared to berberine treatment alone, suggesting the additive effect of other components present. Reduction of tumor size and neovascularization were observed in mice xenograft model. CONCLUSION Our study postulates the antiangiogenic effect of CRAE on hepatocellular carcinoma via an eEF2-driven pathway.
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Affiliation(s)
- Hor Yue Tan
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Ning Wang
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Sai-Wah Tsao
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Zhangjin Zhang
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Yibin Feng
- School of Chinese Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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26
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Grandjean M, Sermeus A, Branders S, Defresne F, Dieu M, Dupont P, Raes M, De Ridder M, Feron O. Hypoxia integration in the serological proteome analysis unmasks tumor antigens and fosters the identification of anti-phospho-eEF2 antibodies as potential cancer biomarkers. PLoS One 2013; 8:e76508. [PMID: 24130777 PMCID: PMC3794947 DOI: 10.1371/journal.pone.0076508] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 08/27/2013] [Indexed: 11/24/2022] Open
Abstract
The expression by tumor cells of proteins with aberrant structure, expression or distribution accounts for the development of a humoral immune response. Autoantibodies (aAb) directed against tumor-associated antigens (TAA) may thus be particularly relevant for early detection of cancer. Serological proteome analysis (SERPA) aims to identify such circulating aAb through the immunoblotting of 2D-separated tumor cell proteins with cancer patient serum and the consecutive MS identification of proteins in reactive spots. This method has the advantage to use post-translationally modified proteins as a source of potential TAA. Here, we applied this strategy by using colorectal tumor cells pre-exposed to hypoxia in order to promote the expression of a pattern of TAA more likely to represent in vivo conditions. We used two human HCT116 and HT29 colorectal cancer cell lines exposed for 48 hours to 1% O2. Spots positive after immunoblotting of 2D-separated lysates of hypoxic cells with the sera of tumor-bearing mice, were collected and analysed by MS for protein identification. Among the hypoxia-specific immunogenic proteins, we identified a phosphorylated form of eukaryotic translation elongation factor 2 (phospho-Thr56 eEF2). We confirmed the increased phosphorylation of this protein in hypoxic colorectal tumor cells as well as in mouse tumors. Using a specific immunoassay, we could detect the presence of corresponding anti-phospho-Thr56 eEF2 aAb in the serum of tumor-bearing mice (vs healthy mice). We further documented that the detection of these aAb preceded the detection of a palpable tumor mass in mice and validated the presence of anti-phospho-Thr56 eEF2 aAb in the serum of patients with adenomatous polyps and colorectal carcinoma. In conclusion, this study validates a phosphorylated form of eEF2 as a new TAA and more generally, provides evidence that integrating hypoxia upstream of SERPA offers a more relevant repertoire of TAA able to unmask the presence of circulating aAb.
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Affiliation(s)
- Marie Grandjean
- UCLouvain, Institut de Recherche Expérimentale et Clinique (IREC), Pole of Pharmacology and Therapeutics (FATH), Brussels, Belgium
| | | | - Samuel Branders
- UCLouvain, Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Machine Learning Group, Louvain-la-Neuve, Belgium
| | - Florence Defresne
- UCLouvain, Institut de Recherche Expérimentale et Clinique (IREC), Pole of Pharmacology and Therapeutics (FATH), Brussels, Belgium
| | - Marc Dieu
- UNamur, Namur Research Institute for Life Sciences (NARILIS), Research Unit of Cell Biology (URBC), Namur, Belgium
| | - Pierre Dupont
- UCLouvain, Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Machine Learning Group, Louvain-la-Neuve, Belgium
| | - Martine Raes
- UNamur, Namur Research Institute for Life Sciences (NARILIS), Research Unit of Cell Biology (URBC), Namur, Belgium
| | - Mark De Ridder
- UZ Brussel, Vrije Universiteit Brussel, Brussels, Belgium
| | - Olivier Feron
- UCLouvain, Institut de Recherche Expérimentale et Clinique (IREC), Pole of Pharmacology and Therapeutics (FATH), Brussels, Belgium
- * E-mail:
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27
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Yi T, Papadopoulos E, Hagner PR, Wagner G. Hypoxia-inducible factor-1α (HIF-1α) promotes cap-dependent translation of selective mRNAs through up-regulating initiation factor eIF4E1 in breast cancer cells under hypoxia conditions. J Biol Chem 2013; 288:18732-42. [PMID: 23667251 DOI: 10.1074/jbc.m113.471466] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Hypoxia promotes tumor evolution and metastasis, and hypoxia-inducible factor-1α (HIF-1α) is a key regulator of hypoxia-related cellular processes in cancer. The eIF4E translation initiation factors, eIF4E1, eIF4E2, and eIF4E3, are essential for translation initiation. However, whether and how HIF-1α affects cap-dependent translation through eIF4Es in hypoxic cancer cells has been unknown. Here, we report that HIF-1α promoted cap-dependent translation of selective mRNAs through up-regulation of eIF4E1 in hypoxic breast cancer cells. Hypoxia-promoted breast cancer tumorsphere growth was HIF-1α-dependent. We found that eIF4E1, not eIF4E2 or eIF4E3, is the dominant eIF4E family member in breast cancer cells under both normoxia and hypoxia conditions. eIF4E3 expression was largely sequestered in breast cancer cells at normoxia and hypoxia. Hypoxia up-regulated the expression of eIF4E1 and eIF4E2, but only eIF4E1 expression was HIF-1α-dependent. In hypoxic cancer cells, HIF-1α-up-regulated eIF4E1 enhanced cap-dependent translation of a subset of mRNAs encoding proteins important for breast cancer cell mammosphere growth. In searching for correlations, we discovered that human eIF4E1 promoter harbors multiple potential hypoxia response elements. Furthermore, using chromatin immunoprecipitation (ChIP) and luciferase and point mutation assays, we found that HIF-1α utilized hypoxia response elements in the human eIF4E1 proximal promoter region to activate eIF4E1 expression. Our study suggests that HIF-1α promotes cap-dependent translation of selective mRNAs through up-regulating eIF4E1, which contributes to tumorsphere growth of breast cancer cells at hypoxia. The data shown provide new insights into protein synthesis mechanisms in cancer cells at low oxygen levels.
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Affiliation(s)
- Tingfang Yi
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA
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