1
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Abstract
Cancers undergo sequential changes to proton (H+) concentration and sensing that are consequences of the disease and facilitate its further progression. The impact of protonation state on protein activity can arise from alterations to amino acids or their titration. Indeed, many cancer-initiating mutations influence pH balance, regulation or sensing in a manner that enables growth and invasion outside normal constraints as part of oncogenic transformation. These cancer-supporting effects become more prominent when tumours develop an acidic microenvironment owing to metabolic reprogramming and disordered perfusion. The ensuing intracellular and extracellular pH disturbances affect multiple aspects of tumour biology, ranging from proliferation to immune surveillance, and can even facilitate further mutagenesis. As a selection pressure, extracellular acidosis accelerates disease progression by favouring acid-resistant cancer cells, which are typically associated with aggressive phenotypes. Although acid-base disturbances in tumours often occur alongside hypoxia and lactate accumulation, there is now ample evidence for a distinct role of H+-operated responses in key events underpinning cancer. The breadth of these actions presents therapeutic opportunities to change the trajectory of disease.
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Affiliation(s)
- Pawel Swietach
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
| | - Stine Falsig Pedersen
- Department of Biology, University of Copenhagen, University of Copenhagen, Faculty of Science, København, Denmark.
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2
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Araya-Secchi R, Bugge K, Seiffert P, Petry A, Haxholm GW, Lindorff-Larsen K, Pedersen SF, Arleth L, Kragelund BB. The prolactin receptor scaffolds Janus kinase 2 via co-structure formation with phosphoinositide-4,5-bisphosphate. eLife 2023; 12:84645. [PMID: 37232489 DOI: 10.7554/elife.84645] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 05/24/2023] [Indexed: 05/27/2023] Open
Abstract
Class 1 cytokine receptors transmit signals through the membrane by a single transmembrane helix to an intrinsically disordered cytoplasmic domain that lacks kinase activity. While specific binding to phosphoinositides has been reported for the prolactin receptor (PRLR), the role of lipids in PRLR signalling is unclear. Using an integrative approach combining NMR spectroscopy, cellular signalling experiments, computational modelling and simulation, we demonstrate co-structure formation of the disordered intracellular domain of the human PRLR, the membrane constituent phosphoinositide-4,5-bisphosphate (PI(4,5)P2) and the FERM-SH2 domain of the Janus kinase 2 (JAK2). We find that the complex leads to accumulation of PI(4,5)P2 at the transmembrane helix interface and that mutation of residues identified to interact specifically with PI(4,5)P2 negatively affects PRLR-mediated activation of signal transducer and activator of transcription 5 (STAT5). Facilitated by co-structure formation, the membrane-proximal disordered region arranges into an extended structure. We suggest that the co-structure formed between PRLR, JAK2 and PI(4,5)P2 locks the juxtamembrane disordered domain of the PRLR in an extended structure, enabling signal relay from the extracellular to the intracellular domain upon ligand binding. We find that the co-structure exists in different states which we speculate could be relevant for turning signalling on and off. Similar co-structures may be relevant for other non-receptor tyrosine kinases and their receptors.
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Affiliation(s)
- Raul Araya-Secchi
- Facultad de Ingenieria Arquitectura y Diseño, Universidad San Sebastian, Santiago, Chile
| | - Katrine Bugge
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Pernille Seiffert
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Amalie Petry
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Gitte W Haxholm
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Lise Arleth
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
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3
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Rolver MG, Holland LKK, Ponniah M, Prasad NS, Yao J, Schnipper J, Kramer S, Elingaard-Larsen L, Pedraz-Cuesta E, Liu B, Pardo LA, Maeda K, Sandelin A, Pedersen SF. Chronic acidosis rewires cancer cell metabolism through PPARα signaling. Int J Cancer 2023; 152:1668-1684. [PMID: 36533672 PMCID: PMC10108231 DOI: 10.1002/ijc.34404] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/25/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022]
Abstract
The mechanisms linking tumor microenvironment acidosis to disease progression are not understood. Here, we used mammary, pancreatic, and colon cancer cells to show that adaptation to growth at an extracellular pH (pHe ) mimicking acidic tumor niches is associated with upregulated net acid extrusion capacity and elevated intracellular pH at physiological pHe , but not at acidic pHe . Using metabolic profiling, shotgun lipidomics, imaging and biochemical analyses, we show that the acid adaptation-induced phenotype is characterized by a shift toward oxidative metabolism, increased lipid droplet-, triacylglycerol-, peroxisome content and mitochondrial hyperfusion. Peroxisome proliferator-activated receptor-α (PPARA, PPARα) expression and activity are upregulated, at least in part by increased fatty acid uptake. PPARα upregulates genes driving increased mitochondrial and peroxisomal mass and β-oxidation capacity, including mitochondrial lipid import proteins CPT1A, CPT2 and SLC25A20, electron transport chain components, peroxisomal proteins PEX11A and ACOX1, and thioredoxin-interacting protein (TXNIP), a negative regulator of glycolysis. This endows acid-adapted cancer cells with increased capacity for utilizing fatty acids for metabolic needs, while limiting glycolysis. As a consequence, the acid-adapted cells exhibit increased sensitivity to PPARα inhibition. We conclude that PPARα is a key upstream regulator of metabolic changes favoring cancer cell survival in acidic tumor niches.
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Affiliation(s)
- Michala G Rolver
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Lya K K Holland
- Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Muthulakshmi Ponniah
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Nanditha S Prasad
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Jiayi Yao
- The Bioinformatics Center, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,Biotech Research and Innovation Center, University of Copenhagen, Copenhagen, Denmark
| | - Julie Schnipper
- Laboratory of Cellular and Molecular Physiology, University of Picardie Jules Verne, Amiens, France
| | - Signe Kramer
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Elena Pedraz-Cuesta
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Bin Liu
- Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Luis A Pardo
- Oncophysiology Group, Max-Planck-Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Kenji Maeda
- Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Albin Sandelin
- The Bioinformatics Center, Department of Biology, University of Copenhagen, Copenhagen, Denmark.,Biotech Research and Innovation Center, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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4
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Severin M, Pedersen EL, Borre MT, Axholm I, Christiansen FB, Ponniah M, Czaplinska D, Larsen T, Pardo LA, Pedersen SF. Dynamic localization of the Na+-HCO3- co-transporter NBCn1 to the plasma membrane, centrosomes, spindle and primary cilia. J Cell Sci 2023; 136:306269. [PMID: 37039101 DOI: 10.1242/jcs.260687] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 02/13/2023] [Indexed: 04/12/2023] Open
Abstract
Finely tuned regulation of transport protein localization is vital for epithelial function. The Na+-HCO3- co-transporter NBCn1 (also known as SLC4A7) is a key contributor to epithelial pH homeostasis, yet the regulation of its subcellular localization is not understood. Here, we show that a predicted N-terminal β-sheet and short C-terminal α-helical motif are essential for NBCn1 plasma membrane localization in epithelial cells. This localization was abolished by cell-cell contact disruption, and co-immunoprecipitation (co-IP) and proximity ligation (PLA) revealed NBCn1 interaction with E-cadherin and DLG1, linking it to adherens junctions and the Scribble complex. NBCn1 also interacted with RhoA and localized to lamellipodia and filopodia in migrating cells. Finally, analysis of native and GFP-tagged NBCn1 localization, subcellular fractionation, co-IP with Arl13B and CEP164, and PLA of NBCn1 and tubulin in mitotic spindles led to the surprising conclusion that NBCn1 additionally localizes to centrosomes and primary cilia in non-dividing, polarized epithelial cells, and to the spindle, centrosomes and midbodies during mitosis. We propose that NBCn1 traffics between lateral junctions, the leading edge and cell division machinery in Rab11 endosomes, adding new insight to the role of NBCn1 in cell cycle progression.
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Affiliation(s)
- Marc Severin
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Emma Lind Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Magnus Thane Borre
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Ida Axholm
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Frederik Bendix Christiansen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Muthulakshmi Ponniah
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Dominika Czaplinska
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Tanja Larsen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
| | - Luis Angel Pardo
- AG Oncophysiology, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37075, Germany
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen 2100, Denmark
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5
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Czaplinska D, Ialchina R, Andersen HB, Yao J, Stigliani A, Dannesboe J, Flinck M, Chen X, Mitrega J, Gnosa SP, Dmytriyeva O, Alves F, Napp J, Sandelin A, Pedersen SF. Crosstalk between tumor acidosis, p53 and extracellular matrix regulates pancreatic cancer aggressiveness. Int J Cancer 2023; 152:1210-1225. [PMID: 36408933 PMCID: PMC10108304 DOI: 10.1002/ijc.34367] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 10/14/2022] [Accepted: 11/07/2022] [Indexed: 11/22/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy with minimal treatment options and a global rise in prevalence. PDAC is characterized by frequent driver mutations including KRAS and TP53 (p53), and a dense, acidic tumor microenvironment (TME). The relation between genotype and TME in PDAC development is unknown. Strikingly, when wild type (WT) Panc02 PDAC cells were adapted to growth in an acidic TME and returned to normal pH to mimic invasive cells escaping acidic regions, they displayed a strong increase of aggressive traits such as increased growth in 3-dimensional (3D) culture, adhesion-independent colony formation and invasive outgrowth. This pattern of acidosis-induced aggressiveness was observed in 3D spheroid culture as well as upon organotypic growth in matrigel, collagen-I and combination thereof, mimicking early and later stages of PDAC development. Acid-adaptation-induced gain of cancerous traits was further increased by p53 knockout (KO), but only in specific extracellular matrix (ECM) compositions. Akt- and Transforming growth factor-β (TGFβ) signaling, as well as expression of the Na+ /H+ exchanger NHE1, were increased by acid adaptation. Whereas Akt inhibition decreased spheroid growth regardless of treatment and genotype, stimulation with TGFβI increased growth of WT control spheroids, and inhibition of TGFβ signaling tended to limit growth under acidic conditions only. Our results indicate that a complex crosstalk between tumor acidosis, ECM composition and genotype contributes to PDAC development. The findings may guide future strategies for acidosis-targeted therapies.
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Affiliation(s)
- Dominika Czaplinska
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Renata Ialchina
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Henriette Berg Andersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jiayi Yao
- Section for Computational and RNA Biology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), Faculty of Health, University of Copenhagen, Copenhagen, Denmark
| | - Arnaud Stigliani
- Section for Computational and RNA Biology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), Faculty of Health, University of Copenhagen, Copenhagen, Denmark
| | - Johs Dannesboe
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Mette Flinck
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Xiaoming Chen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jakub Mitrega
- Max-Planck-Institute for Multidisciplinary Sciences, Goettingen, Germany.,Institute for Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany
| | - Sebastian Peter Gnosa
- Biotech Research and Innovation Centre (BRIC), Faculty of Health, University of Copenhagen, Copenhagen, Denmark
| | - Oksana Dmytriyeva
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health, University of Copenhagen, Copenhagen, Denmark
| | - Frauke Alves
- Max-Planck-Institute for Multidisciplinary Sciences, Goettingen, Germany.,Institute for Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany.,Clinic of Haematology and Medical Oncology, University Medical Center Goettingen, Goettingen, Germany
| | - Joanna Napp
- Max-Planck-Institute for Multidisciplinary Sciences, Goettingen, Germany.,Institute for Diagnostic and Interventional Radiology, University Medical Center Goettingen, Goettingen, Germany.,Clinic of Haematology and Medical Oncology, University Medical Center Goettingen, Goettingen, Germany
| | - Albin Sandelin
- Section for Computational and RNA Biology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), Faculty of Health, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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6
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Andersen HB, Ialchina R, Pedersen SF, Czaplinska D. Metabolic reprogramming by driver mutation-tumor microenvironment interplay in pancreatic cancer: new therapeutic targets. Cancer Metastasis Rev 2021; 40:1093-1114. [PMID: 34855109 DOI: 10.1007/s10555-021-10004-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 11/22/2021] [Indexed: 12/12/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers globally with a mortality rate exceeding 95% and very limited therapeutic options. A hallmark of PDAC is its acidic tumor microenvironment, further characterized by excessive fibrosis and depletion of oxygen and nutrients due to poor vascularity. The combination of PDAC driver mutations and adaptation to this hostile environment drives extensive metabolic reprogramming of the cancer cells toward non-canonical metabolic pathways and increases reliance on scavenging mechanisms such as autophagy and macropinocytosis. In addition, the cancer cells benefit from metabolic crosstalk with nonmalignant cells within the tumor microenvironment, including pancreatic stellate cells, fibroblasts, and endothelial and immune cells. Increasing evidence shows that this metabolic rewiring is closely related to chemo- and radioresistance and immunosuppression, causing extensive treatment failure. Indeed, stratification of human PDAC tumors into subtypes based on their metabolic profiles was shown to predict disease outcome. Accordingly, an increasing number of clinical trials target pro-tumorigenic metabolic pathways, either as stand-alone treatment or in conjunction with chemotherapy. In this review, we highlight key findings and potential future directions of pancreatic cancer metabolism research, specifically focusing on novel therapeutic opportunities.
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Affiliation(s)
- Henriette Berg Andersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Renata Ialchina
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, 2100, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, 2100, Copenhagen, Denmark.
| | - Dominika Czaplinska
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, 2100, Copenhagen, Denmark
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7
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Doray A, Lemoine R, Severin M, Chadet S, Lopez-Charcas O, Héraud A, Baron C, Besson P, Monteil A, Pedersen SF, Roger S. The Voltage-Gated Sodium Channel Beta4 Subunit Maintains Epithelial Phenotype in Mammary Cells. Cells 2021; 10:cells10071624. [PMID: 34209614 PMCID: PMC8304757 DOI: 10.3390/cells10071624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/17/2021] [Accepted: 06/25/2021] [Indexed: 11/16/2022] Open
Abstract
The SCN4B gene, coding for the NaVβ4 subunit of voltage-gated sodium channels, was recently found to be expressed in normal epithelial cells and down-regulated in several cancers. However, its function in normal epithelial cells has not been characterized. In this study, we demonstrated that reducing NaVβ4 expression in MCF10A non-cancer mammary epithelial cells generated important morphological changes observed both in two-dimensional cultures and in three-dimensional cysts. Most notably, the loss of NaVβ4 induced a complete loss of epithelial organisation in cysts and increased proteolytic activity towards the extracellular matrix. Loss of epithelial morphology was associated with an increased degradation of β-catenin, reduced E-cadherin expression and induction of mesenchymal markers N-cadherin, vimentin, and α-SMA expression. Overall, our results suggest that Navβ4 may participate in the maintenance of the epithelial phenotype in mammary cells and that its downregulation might be a determining step in early carcinogenesis.
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Affiliation(s)
- Adélaïde Doray
- Transplantation, Immunologie et Inflammation T2I-EA 4245, Université de Tours, 37044 Tours, France; (A.D.); (R.L.); (S.C.); (O.L.-C.); (A.H.); (C.B.); (P.B.)
| | - Roxane Lemoine
- Transplantation, Immunologie et Inflammation T2I-EA 4245, Université de Tours, 37044 Tours, France; (A.D.); (R.L.); (S.C.); (O.L.-C.); (A.H.); (C.B.); (P.B.)
| | - Marc Severin
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark; (M.S.); (S.F.P.)
| | - Stéphanie Chadet
- Transplantation, Immunologie et Inflammation T2I-EA 4245, Université de Tours, 37044 Tours, France; (A.D.); (R.L.); (S.C.); (O.L.-C.); (A.H.); (C.B.); (P.B.)
| | - Osbaldo Lopez-Charcas
- Transplantation, Immunologie et Inflammation T2I-EA 4245, Université de Tours, 37044 Tours, France; (A.D.); (R.L.); (S.C.); (O.L.-C.); (A.H.); (C.B.); (P.B.)
| | - Audrey Héraud
- Transplantation, Immunologie et Inflammation T2I-EA 4245, Université de Tours, 37044 Tours, France; (A.D.); (R.L.); (S.C.); (O.L.-C.); (A.H.); (C.B.); (P.B.)
| | - Christophe Baron
- Transplantation, Immunologie et Inflammation T2I-EA 4245, Université de Tours, 37044 Tours, France; (A.D.); (R.L.); (S.C.); (O.L.-C.); (A.H.); (C.B.); (P.B.)
| | - Pierre Besson
- Transplantation, Immunologie et Inflammation T2I-EA 4245, Université de Tours, 37044 Tours, France; (A.D.); (R.L.); (S.C.); (O.L.-C.); (A.H.); (C.B.); (P.B.)
| | - Arnaud Monteil
- Institut de Génomique Fonctionnelle, University of Montpellier, CNRS UMR 5203, INSERM U1191, 34094 Montpellier, France;
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, 2100 Copenhagen, Denmark; (M.S.); (S.F.P.)
| | - Sébastien Roger
- Transplantation, Immunologie et Inflammation T2I-EA 4245, Université de Tours, 37044 Tours, France; (A.D.); (R.L.); (S.C.); (O.L.-C.); (A.H.); (C.B.); (P.B.)
- Institut Universitaire de France (IUF), 75231 Paris, France
- Correspondence: ; Tel.: +33-247-36-61-30
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8
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Sjøgaard-Frich LM, Prestel A, Pedersen ES, Severin M, Kristensen KK, Olsen JG, Kragelund BB, Pedersen SF. Dynamic Na +/H + exchanger 1 (NHE1) - calmodulin complexes of varying stoichiometry and structure regulate Ca 2+-dependent NHE1 activation. eLife 2021; 10:60889. [PMID: 33655882 PMCID: PMC8009664 DOI: 10.7554/elife.60889] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 03/01/2021] [Indexed: 11/25/2022] Open
Abstract
Calmodulin (CaM) engages in Ca2+-dependent interactions with numerous proteins, including a still incompletely understood physical and functional interaction with the human Na+/H+-exchanger NHE1. Using nuclear magnetic resonance (NMR) spectroscopy, isothermal titration calorimetry, and fibroblasts stably expressing wildtype and mutant NHE1, we discovered multiple accessible states of this functionally important complex existing in different NHE1:CaM stoichiometries and structures. We determined the NMR solution structure of a ternary complex in which CaM links two NHE1 cytosolic tails. In vitro, stoichiometries and affinities could be tuned by variations in NHE1:CaM ratio and calcium ([Ca2+]) and by phosphorylation of S648 in the first CaM-binding α-helix. In cells, Ca2+-CaM-induced NHE1 activity was reduced by mimicking S648 phosphorylation and by mutation of the first CaM-binding α-helix, whereas it was unaffected by inhibition of Akt, one of several kinases phosphorylating S648. Our results demonstrate a diversity of NHE1:CaM interaction modes and suggest that CaM may contribute to NHE1 dimerization and thereby augment NHE1 regulation. We propose that a similar structural diversity is of relevance to many other CaM complexes.
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Affiliation(s)
- Lise M Sjøgaard-Frich
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Prestel
- Structural Biology and NMR Laboratory, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Emilie S Pedersen
- Structural Biology and NMR Laboratory, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Marc Severin
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Kristian Kølby Kristensen
- Finsen Laboratory, Rigshospitalet, Copenhagen, Denmark.,Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Johan G Olsen
- Structural Biology and NMR Laboratory, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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9
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Rolver MG, Pedersen SF. Putting Warburg to work: how imaging of tumour acidosis could help predict metastatic potential in breast cancer. Br J Cancer 2020; 124:1-2. [PMID: 33257840 PMCID: PMC7782540 DOI: 10.1038/s41416-020-01171-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 10/30/2020] [Accepted: 11/02/2020] [Indexed: 11/24/2022] Open
Abstract
Solid tumours are often highly acidic compared to normal tissue, and tumour extracellular acidosis contributes to multiple aspects of cancer progression. Now, Anemone et al. in this issue of the British Journal of Cancer provide in vivo evidence that the degree to which various breast cancer cell lines acidify their environment correlates with their ability to metastasise to the lungs. This indicates that measurements of tumour extracellular acidosis have the potential to become a clinical tool for assessing the risk of metastasis.
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Affiliation(s)
- Michala Gylling Rolver
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
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10
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Yao J, Czaplinska D, Ialchina R, Schnipper J, Liu B, Sandelin A, Pedersen SF. Cancer Cell Acid Adaptation Gene Expression Response Is Correlated to Tumor-Specific Tissue Expression Profiles and Patient Survival. Cancers (Basel) 2020; 12:cancers12082183. [PMID: 32764426 PMCID: PMC7463722 DOI: 10.3390/cancers12082183] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/21/2020] [Accepted: 07/31/2020] [Indexed: 12/13/2022] Open
Abstract
The acidic pH of the tumor microenvironment plays a critical role in driving cancer development toward a more aggressive phenotype, but the underlying mechanisms are unclear. To this end, phenotypic and genotypic changes induced by adaptation of cancer cells to chronic acidosis have been studied. However, the generality of acid adaptation patterns across cell models and their correlation to the molecular phenotypes and aggressiveness of human cancers are essentially unknown. Here, we define an acid adaptation expression response shared across three cancer cell models, dominated by metabolic rewiring, extracellular matrix remodeling, and altered cell cycle regulation and DNA damage response. We find that many genes which are upregulated by acid adaptation are significantly correlated to patient survival, and more generally, that there are clear correlations between acid adaptation expression response and gene expression change between normal and tumor tissues, for a large subset of cancer patients. Our data support the notion that tumor microenvironment acidity is one of the key factors driving the selection of aggressive cancer cells in human patient tumors, yet it also induces a growth-limiting genotype that likely limits cancer cell growth until the cells are released from acidosis, for instance during invasion.
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Affiliation(s)
- Jiayi Yao
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, DK2200 Copenhagen, Denmark;
- Biotech Research and Innovation Centre, University of Copenhagen, DK2200 Copenhagen, Denmark
| | - Dominika Czaplinska
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, DK2100 Copenhagen, Denmark; (D.C.); (R.I.); (J.S.)
| | - Renata Ialchina
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, DK2100 Copenhagen, Denmark; (D.C.); (R.I.); (J.S.)
| | - Julie Schnipper
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, DK2100 Copenhagen, Denmark; (D.C.); (R.I.); (J.S.)
| | - Bin Liu
- Cell Death and Metabolism, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, DK2100 Copenhagen, Denmark;
| | - Albin Sandelin
- The Bioinformatics Centre, Department of Biology, University of Copenhagen, DK2200 Copenhagen, Denmark;
- Biotech Research and Innovation Centre, University of Copenhagen, DK2200 Copenhagen, Denmark
- Correspondence: (A.S.); (S.F.P.)
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, DK2100 Copenhagen, Denmark; (D.C.); (R.I.); (J.S.)
- Correspondence: (A.S.); (S.F.P.)
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11
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Flinck M, Hagelund S, Gorbatenko A, Severin M, Pedraz-Cuesta E, Novak I, Stock C, Pedersen SF. The Vacuolar H + ATPase α3 Subunit Negatively Regulates Migration and Invasion of Human Pancreatic Ductal Adenocarcinoma Cells. Cells 2020; 9:E465. [PMID: 32085585 PMCID: PMC7072798 DOI: 10.3390/cells9020465] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/10/2020] [Accepted: 02/13/2020] [Indexed: 12/12/2022] Open
Abstract
Increased metabolic acid production and upregulation of net acid extrusion render pH homeostasis profoundly dysregulated in many cancers. Plasma membrane activity of vacuolar H+ ATPases (V-ATPases) has been implicated in acid extrusion and invasiveness of some cancers, yet often on the basis of unspecific inhibitors. Serving as a membrane anchor directing V-ATPase localization, the a subunit of the V0 domain of the V-ATPase (ATP6V0a1-4) is particularly interesting in this regard. Here, we map the regulation and roles of ATP6V0a3 in migration, invasion, and growth in pancreatic ductal adenocarcinoma (PDAC) cells. a3 mRNA and protein levels were upregulated in PDAC cell lines compared to non-cancer pancreatic epithelial cells. Under control conditions, a3 localization was mainly endo-/lysosomal, and its knockdown had no detectable effect on pHi regulation after acid loading. V-ATPase inhibition, but not a3 knockdown, increased HIF-1 expression and decreased proliferation and autophagic flux under both starved and non-starved conditions, and spheroid growth of PDAC cells was also unaffected by a3 knockdown. Strikingly, a3 knockdown increased migration and transwell invasion of Panc-1 and BxPC-3 PDAC cells, and increased gelatin degradation in BxPC-3 cells yet decreased it in Panc-1 cells. We conclude that in these PDAC cells, a3 is upregulated and negatively regulates migration and invasion, likely in part via effects on extracellular matrix degradation.
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Affiliation(s)
- Mette Flinck
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Sofie Hagelund
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Andrej Gorbatenko
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Marc Severin
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Elena Pedraz-Cuesta
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Ivana Novak
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
| | - Christian Stock
- Department of Gastroentero-, Hepato- and Endocrinology, Hannover Medical School, D-30625 Hannover, Germany;
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, DK-2100 Copenhagen, Denmark; (M.F.); (S.H.); (M.S.); (E.P.-C.); (I.N.)
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12
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Thiesen L, Belew ZM, Griem-Krey N, Pedersen SF, Crocoll C, Nour-Eldin HH, Wellendorph P. The γ-hydroxybutyric acid (GHB) analogue NCS-382 is a substrate for both monocarboxylate transporters subtypes 1 and 4. Eur J Pharm Sci 2020; 143:105203. [PMID: 31866563 DOI: 10.1016/j.ejps.2019.105203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 12/11/2019] [Accepted: 12/19/2019] [Indexed: 11/20/2022]
Abstract
The small-molecule ligand (E)-2-(5-hydroxy-5,7,8,9-tetrahydro-6H-benzo[7]annulen-6-ylidene)acetic acid (NCS-382) is an analogue of γ-hydroxybutyric acid (GHB) and is widely used for probing the brain-specific GHB high-affinity binding sites. To reach these, brain uptake is imperative, and it is therefore important to understand the molecular mechanisms of NCS-382 transport in order to direct in vivo studies. In this study, we hypothesized that NCS-382 is a substrate for the monocarboxylate transporter subtype 1 (MCT1) which is known to mediate blood-brain barrier (BBB) permeation of GHB. For this purpose, we investigated NCS-382 uptake by MCT subtypes endogenously expressed in tsA201 and MDA-MB-231 cell lines in assays of radioligand-based competition and fluorescence-based intracellular pH measurements. To further verify the results, we measured NCS-382 uptake by means of mass spectrometry in Xenopus laevis oocytes heterologously expressing MCT subtypes. As expected, we found that NCS-382 is a substrate for MCT1 with half-maximal effective concentrations in the low millimolar range. Surprisingly, NCS-382 also showed substrate activity at MCT4 as well as uptake in water-injected oocytes, suggesting a component of passive diffusion. In conclusion, transport of NCS-382 across membranes differs from GHB as it also involves MCT4 and/or passive diffusion. This should be taken into consideration when designing pharmacological studies with this compound and its closely related analogues. The combination of MCT assays used here exemplifies a setup that may be suitable for a reliable characterization of MCT ligands in general.
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Affiliation(s)
- Louise Thiesen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Zeinu Mussa Belew
- DynaMo Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
| | - Nane Griem-Krey
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen Ø, Denmark
| | - Christoph Crocoll
- DynaMo Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
| | - Hussam Hassan Nour-Eldin
- DynaMo Center, Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Frederiksberg C, Denmark
| | - Petrine Wellendorph
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
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13
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Avnet S, Baldini N, Brisson L, Pedersen SF, Porporato PE, Sonveaux P, Szabadkai G, Pastorekova S. Annual Meeting of the International Society of Cancer Metabolism (ISCaM): Metabolic Adaptations and Targets in Cancer. Front Oncol 2019; 9:1332. [PMID: 31850217 PMCID: PMC6892776 DOI: 10.3389/fonc.2019.01332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 11/14/2019] [Indexed: 11/18/2022] Open
Abstract
The metabolism of cancer cells differs from that of their normal counterparts in a spectrum of attributes, including imbalances in diverse metabolic arms and pathways, metabolic plasticity and extent of adaptive responses, levels, and activities of metabolic enzymes and their upstream regulators and abnormal fluxes of metabolic intermediates and products. These attributes endow cancer cells with the ability to survive stressors of the tumor microenvironment and enable them to landscape and exploit the host terrain, thereby facilitating cancer progression and therapy resistance. Understanding the molecular and physiological principles of cancer metabolism is one of the key prerequisites for the development of better anticancer treatments. Therefore, various aspects of cancer metabolism were addressed at the 5th annual meeting of the International Society of Cancer Metabolism (ISCaM) in Bratislava, Slovakia, on October 17–20, 2018. The meeting presentations and discussions were traditionally focused on mechanistic, translational, and clinical characteristics of metabolism and pH control in cancer, at the level of molecular pathways, cells, tissues, and organisms. In order to reflect major healthcare challenges of the current era, ISCaM has extended its scope to metabolic disorders contributing to cancer, as well as to opportunities for their prevention, intervention, and therapeutic targeting.
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Affiliation(s)
- Sofia Avnet
- Orthopaedic Pathophysiology and Regenerative Medicine Unit, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Nicola Baldini
- Orthopaedic Pathophysiology and Regenerative Medicine Unit, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.,Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Lucie Brisson
- INSERM UMR1069, Nutrition, Croissance et Cancer, University of Tours, Tours, France
| | - Stine Falsig Pedersen
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Paolo E Porporato
- Department of Molecular Biotechnology and Health Science, Molecular Biotechnology Center, University of Torino, Turin, Italy
| | - Pierre Sonveaux
- Pole of Pharmacology and Therapeutics, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Gyorgy Szabadkai
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Department of Cell and Developmental Biology, Consortium for Mitochondrial Research, University College London, London, United Kingdom.,The Francis Crick Institute, London, United Kingdom
| | - Silvia Pastorekova
- Biomedical Research Center, Slovak Academy of Sciences, Bratislava, Slovakia
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14
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Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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15
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Grandjean CE, Korshin A, Smerup M, Jensen JK, Follin B, Brandt-Larsen M, Pedersen SF, Ripa RS, Binderup T, Kjaer A. P1215Non-invasive angiogenesis assessment with PET/CT in a rabbit model of myocardial infarction: feasibility and comparison with molecular markers. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
Translational molecular imaging using Positron Emission Tomography/Computed Tomography (PET/CT) and Transesophageal Echocardiography (TEE) are powerful non-invasive tools for investigation and monitoring of cardiovascular functions. Following myocardial infarction (MI), formation of new blood vessels (angiogenesis) is of importance in the healing process and can be assessed with the PET tracer 68Ga-NODAGA-E[(cRGDyK)]2 (68Ga-RGD).
Purpose
The purpose of the study was to assess angiogenesis in a rabbit model of myocardial infarction using molecular imaging (PET/CT) and furthermore to validate the findings using TEE, immunohistochemistry (IHC) and quantitative PCR (qPCR).
Methods
Ten NZW rabbits were used (MI: n=5, SHAM: n=5). Angiogenesis was assessed with 68Ga-RGD before, 1 and 3 weeks after interventions using PET/CT (Inveon System, Siemens Health Care). TEE was used per-operatively and at termination for assessment of the MI (S8–3T probe, iE33 System, Phillips). Following the final scans, hearts were harvested for ex vivo analyses. Short axis slides were stained for collagen deposition and myocardial differentiation (H&E and Masson's trichrome), endothelial cells (CD31), and macrophage infiltration (RAM11). Gene expression alterations related to wound healing response (inflammation, granulation, and tissue remodeling) were measured using qPCR arrays (84 genes analyzed).
Results
One week after the interventions, 68Ga-RGD uptake, as assessed with PET was increased in the infarct area when compared to the remote zone of the same rabbit as well as compared to the SHAM group. Three weeks after intervention, there was no difference in 68Ga-RGD uptake between groups. High quality TEE images were obtained in all rabbits. Ex vivo analyses at 3 weeks after intervention revealed moderate vessel formation (CD31) in the infarct zone, none in the border zone, whereas surrounding viable myocardium had visible CD31 positive vessels comparable to the SHAM group. Macrophage infiltration (RAM11) and collagenous scaring (Masson's trichrome) was pronounced in the infarcted area. Gene expression alterations in the infarct area (30 of 84 genes upregulated) were dominated by increased expression of collagens (COL1A2, COL5A1, COL5A4), inflammatory chemokines and cytokines (CCL2, IL1A, IL1B, IL6, IL10) and ECM remodeling enzymes (uPAR, TPA, TIMP1, SERPINE1, MMP9) in the MI group compared to the SHAM group, whereas integrins involved in the angiogenesis response (ITGA4, ITGAV) were only moderately changed in the infarction at termination, confirming the in vivo PET findings.
Study outline
Conclusions
In this rabbit MI model, we demonstrate the feasibility of monitoring angiogenesis in the healing process non-invasively with PET. The imaging results were confirmed by IHC and gene expression analysis. Moreover, TEE using a dedicated pediatric probe is feasible in the rabbit model, making this a robust and translational medium-sized animal model of myocardial infarction.
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Affiliation(s)
- C E Grandjean
- Rigshospitalet - Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Copenhagen, Denmark
| | - A Korshin
- Rigshospitalet - Copenhagen University Hospital, Department of Cardiothoracic Anesthesiology, Copenhagen, Denmark
| | - M Smerup
- Rigshospitalet - Copenhagen University Hospital, Department of Cardiothoracic Surgery RT, Copenhagen, Denmark
| | - J K Jensen
- Rigshospitalet - Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Copenhagen, Denmark
| | - B Follin
- Rigshospitalet - Copenhagen University Hospital, Cardiology Stem Cell Centre, Copenhagen, Denmark
| | - M Brandt-Larsen
- Rigshospitalet - Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Copenhagen, Denmark
| | - S F Pedersen
- Rigshospitalet - Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Copenhagen, Denmark
| | - R S Ripa
- Rigshospitalet - Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Copenhagen, Denmark
| | - T Binderup
- Rigshospitalet - Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Copenhagen, Denmark
| | - A Kjaer
- Rigshospitalet - Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Copenhagen, Denmark
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16
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Tornabene E, Helms HCC, Pedersen SF, Brodin B. Effects of oxygen-glucose deprivation (OGD) on barrier properties and mRNA transcript levels of selected marker proteins in brain endothelial cells/astrocyte co-cultures. PLoS One 2019; 14:e0221103. [PMID: 31425564 PMCID: PMC6699694 DOI: 10.1371/journal.pone.0221103] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 07/30/2019] [Indexed: 12/18/2022] Open
Abstract
Ischemic stroke has been shown to induce breakdown of the blood-brain barrier, although these changes are not fully characterized. Oxygen-glucose deprivation (OGD) has been used to investigate the effects of ischemia in cultured brain capillary endothelial cells, however this involves a change of medium which in itself may affect the cells. The aim of the present study was to investigate the effect of OGD and simple medium exchange followed by 48 h of reperfusion on barrier properties of primary bovine endothelial cells co-cultured with rat astrocytes. Barrier properties were evaluated by transendothelial electrical resistance measurements, passive permeability of flux markers, RT-qPCR and immunocytochemistry. Both OGD and simple medium exchange caused an increase in endothelial monolayer permeability. This correlated with reduced transcript levels of a number of tight junction and tight junction-associated proteins (claudin-1, claudin-5, occludin, ZO-1, tricellulin, marveld3 and PECAM-1), as well as with altered transcript level of several transporters and receptors (GLUT-1, HB-EGF, InsR, TfR, two members of the low density lipoprotein receptor family, LDLR and LRP-1, and the efflux transporter BCRP). In contrast, effects induced specifically by OGD were transient de-localization of claudin-5 from the junction zone, increased InsR localization at the plasma membrane and transient downregulation of MRP-1 and P-gp transcript levels. In conclusion, OGD caused changes in claudin-5 and InsR localization, as well as in MRP-1 and P-gp transcript levels. Our results however also indicated that medium exchange alone caused changes in functional barrier properties and expression levels of wide range of proteins.
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Affiliation(s)
- Erica Tornabene
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Stine Falsig Pedersen
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Birger Brodin
- Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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17
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Gorbatenko A, Søkilde R, Sorensen EE, Newie I, Persson H, Morancho B, Arribas J, Litman T, Rovira C, Pedersen SF. HER2 and p95HER2 differentially regulate miRNA expression in MCF-7 breast cancer cells and downregulate MYB proteins through miR-221/222 and miR-503. Sci Rep 2019; 9:3352. [PMID: 30833639 PMCID: PMC6399295 DOI: 10.1038/s41598-019-39733-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 02/04/2019] [Indexed: 12/18/2022] Open
Abstract
The HER2 oncogene and its truncated form p95HER2 play central roles in breast cancer. Here, we show that although HER2 and p95HER2 generally elicit qualitatively similar changes in miRNA profile in MCF-7 breast cancer cells, a subset of changes are distinct and p95HER2 shifts the miRNA profile towards the basal breast cancer subtype. High-throughput miRNA profiling was carried out 15, 36 and 60 h after HER2 or p95HER2 expression and central hits validated by RT-qPCR. miRNAs strongly regulated by p95HER2 yet not by HER2, included miR-221, miR-222, miR-503, miR-29a, miR-149, miR-196 and miR-361. Estrogen receptor-α (ESR1) expression was essentially ablated by p95HER2 expression, in a manner recapitulated by miR-221/-222 mimics. c-Myb family transcription factors MYB and MYBL1, but not MYBL2, were downregulated by p95HER2 and by miR-503 or miR-221/-222 mimics. MYBL1 3′UTR inhibition by miR-221/222 was lost by deletion of a single putative miR-221/222 binding sites. p95HER2 expression, or knockdown of either MYB protein, elicited upregulation of tissue inhibitor of matrix metalloprotease-2 (TIMP2). miR-221/222 and -503 mimics increased, and TIMP2 knockdown decreased, cell migration and invasion. A similar pathway was operational in T47D- and SKBr-3 cells. This work reveals important differences between HER2- and p95HER2- mediated miRNA changes in breast cancer cells, provides novel mechanistic insight into regulation of MYB family transcription factors by p95HER2, and points to a role for a miR-221/222– MYB family–TIMP2 axis in regulation of motility in breast cancer cells.
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Affiliation(s)
- Andrej Gorbatenko
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, New York, 10029, USA.,Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Rolf Søkilde
- BioCare, Strategic Cancer Research Program, Lund, Sweden.,Department of Clinical Sciences Lund, Oncology and Pathology, Faculty of Medicine, Lund University, Lund, Sweden
| | - Ester E Sorensen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Inga Newie
- BioCare, Strategic Cancer Research Program, Lund, Sweden.,Department of Clinical Sciences Lund, Oncology and Pathology, Faculty of Medicine, Lund University, Lund, Sweden
| | - Helena Persson
- BioCare, Strategic Cancer Research Program, Lund, Sweden.,Department of Clinical Sciences Lund, Oncology and Pathology, Faculty of Medicine, Lund University, Lund, Sweden
| | - Beatriz Morancho
- Preclinical Research Program, Vall d'Hebron Institute of Oncology and CIBERONC, 08035, Barcelona, Spain
| | - Joaquin Arribas
- Preclinical Research Program, Vall d'Hebron Institute of Oncology and CIBERONC, 08035, Barcelona, Spain.,Department of Biochemistry and Molecular Biology, Universitat Autonoma de Barcelona, Campus de la UAB, JA, Bellaterra, Spain.,Institució Catalana de Recerca i Estudis Avançats, JA, Barcelona, Spain
| | - Thomas Litman
- Department of International Health, Immunology and Microbiology, University of Copenhagen, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Carlos Rovira
- BioCare, Strategic Cancer Research Program, Lund, Sweden.,Department of Clinical Sciences Lund, Oncology and Pathology, Faculty of Medicine, Lund University, Lund, Sweden
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
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18
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Flinck M, Kramer SH, Schnipper J, Andersen AP, Pedersen SF. The acid-base transport proteins NHE1 and NBCn1 regulate cell cycle progression in human breast cancer cells. Cell Cycle 2018; 17:1056-1067. [PMID: 29895196 DOI: 10.1080/15384101.2018.1464850] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Precise acid-base homeostasis is essential for maintaining normal cell proliferation and growth. Conversely, dysregulated acid-base homeostasis, with increased acid extrusion and marked extracellular acidification, is an enabling feature of solid tumors, yet the mechanisms through which intra- and extracellular pH (pHi, pHe) impact proliferation and growth are incompletely understood. The aim of this study was to determine the impact of pH, and specifically of the Na+/H+ exchanger NHE1 and Na+, HCO3- transporter NBCn1, on cell cycle progression and its regulators in human breast cancer cells. Reduction of pHe to 6.5, a common condition in tumors, significantly delayed cell cycle progression in MCF-7 human breast cancer cells. The NHE1 protein level peaked in S phase and that of NBCn1 in G2/M. Steady state pHi changed through the cell cycle, from 7.1 in early S phase to 6.8 in G2, recovering again in M phase. This pattern, as well as net acid extrusion capacity, was dependent on NHE1 and NBCn1. Accordingly, knockdown of either NHE1 or NBCn1 reduced proliferation, prolonged cell cycle progression in a manner involving S phase prolongation and delayed G2/M transition, and altered the expression pattern and phosphorylation of cell cycle regulatory proteins. Our work demonstrates, for the first time, that both NHE1 and NBCn1 regulate cell cycle progression in breast cancer cells, and we propose that this involves cell cycle phase-specific pHi regulation by the two transporters.
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Affiliation(s)
- Mette Flinck
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
| | - Signe Hoejland Kramer
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
| | - Julie Schnipper
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
| | - Anne Poder Andersen
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
| | - Stine Falsig Pedersen
- a Section for Cell Biology and Physiology, Department of Biology , University of Copenhagen , Copenhagen Ø , Denmark
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19
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Olesen CW, Vogensen J, Axholm I, Severin M, Schnipper J, Pedersen IS, von Stemann JH, Schrøder JM, Christensen DP, Pedersen SF. Trafficking, localization and degradation of the Na +,HCO 3- co-transporter NBCn1 in kidney and breast epithelial cells. Sci Rep 2018; 8:7435. [PMID: 29743600 PMCID: PMC5943355 DOI: 10.1038/s41598-018-25059-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 04/13/2018] [Indexed: 01/28/2023] Open
Abstract
The Na+;HCO3− co-transporter NBCn1 (SLC4A7) is a major regulator of intracellular pH yet its trafficking and turnover are essentially unstudied. Here, we used MDCK-II and MCF-7 cells to investigate these processes in epithelial cells. GFP-NBCn1 membrane localization was abolished by truncation of the full NBCn1 C-terminal tail (C-tail) yet did not require the C-terminal PDZ-binding motif (ETSL). Glutathione-S-Transferase-pulldown of the C-tail followed by mass spectrometry analysis revealed putative interactions with multiple sorting-, degradation- and retention factors, including the scaffolding protein RACK1. Pulldown of FLAG-tagged deletion constructs mapped the RACK1 interaction to the proximal NBCn1 C-tail. Proximity Ligation Assay and co-immunoprecipitation confirmed that native NBCn1 interacts with RACK1 in a cellular context. Consistent with a functional role of this complex, RACK1 knockdown reduced NBCn1 membrane localization without affecting total NBCn1 expression. Notably, only non-confluent cells exhibited detectable NBCn1-RACK1 plasma membrane co-localization, suggesting that RACK1 regulates the trafficking of NBCn1 to the membrane. Whereas total NBCn1 degradation was slow, with a half-life of more than 24 h, one-third of surface NBCn1 was constitutively endocytosed from the basolateral membrane within 60 min. This suggests that a fraction of NBCn1 exhibits recycling between the basolateral membrane and intracellular compartment(s). Our findings have important implications for understanding NBCn1 regulation as well as its dysregulation in disease.
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Affiliation(s)
- Christina Wilkens Olesen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Jens Vogensen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Ida Axholm
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Marc Severin
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Julie Schnipper
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Isabella Skandorff Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Jakob Hjorth von Stemann
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Jacob Morville Schrøder
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark
| | - Dan Ploug Christensen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark.
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen Ø, Denmark.
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Andersen AP, Samsøe-Petersen J, Oernbo EK, Boedtkjer E, Moreira JMA, Kveiborg M, Pedersen SF. The net acid extruders NHE1, NBCn1 and MCT4 promote mammary tumor growth through distinct but overlapping mechanisms. Int J Cancer 2018; 142:2529-2542. [PMID: 29363134 DOI: 10.1002/ijc.31276] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 12/16/2017] [Accepted: 01/17/2018] [Indexed: 01/01/2023]
Abstract
High metabolic and proliferative rates in cancer cells lead to production of large amounts of H+ and CO2 , and as a result, net acid extruding transporters are essential for the function and survival of cancer cells. We assessed protein expression of the Na+ /H+ exchanger NHE1, the Na+ - HCO3- cotransporter NBCn1, and the lactate-H+ cotransporters MCT1 and -4 by immunohistochemical analysis of a large cohort of breast cancer samples. We found robust expression of these transporters in 20, 10, 4 and 11% of samples, respectively. NHE1 and NBCn1 expression both correlated positively with progesterone receptor status, NHE1 correlated negatively and NBCn1 positively with HER2 status, whereas MCT4 expression correlated with lymph node status. Stable shRNA-mediated knockdown (KD) of either NHE1 or NBCn1 in the MDA-MB-231 triple-negative breast cancer (TNBC) cell line significantly reduced steady-state intracellular pH (pHi ) and capacity for pHi recovery after an acid load. Importantly, KD of any of the three transporters reduced in vivo primary tumor growth of MDA-MB-231 xenografts. However, whereas KD of NBCn1 or MCT4 increased tumor-free survival and decreased in vitro proliferation rate and colony growth in soft agar, KD of NHE1 did not have these effects. Moreover, only MCT4 KD reduced Akt kinase activity, PARP and CD147 expression and cell motility. This work reveals that different types of net acid extruding transporters, NHE1, NBCn1 and MCT4, are frequently expressed in patient mammary tumor tissue and demonstrates for the first time that they promote growth of TNBC human mammary tumors in vivo via distinct but overlapping mechanisms.
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Affiliation(s)
- Anne Poder Andersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Jacob Samsøe-Petersen
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Eva Kjer Oernbo
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - José M A Moreira
- Section for Molecular Disease Biology, Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Marie Kveiborg
- Biotech Research and Innovation Centre (BRIC), Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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Pedersen AK, Mendes Lopes de Melo J, Mørup N, Tritsaris K, Pedersen SF. Tumor microenvironment conditions alter Akt and Na +/H + exchanger NHE1 expression in endothelial cells more than hypoxia alone: implications for endothelial cell function in cancer. BMC Cancer 2017; 17:542. [PMID: 28806945 PMCID: PMC5556346 DOI: 10.1186/s12885-017-3532-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 08/03/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Chronic angiogenesis is a hallmark of most tumors and takes place in a hostile tumor microenvironment (TME) characterized by hypoxia, low nutrient and glucose levels, elevated lactate and low pH. Despite this, most studies addressing angiogenic signaling use hypoxia as a proxy for tumor conditions. Here, we compared the effects of hypoxia and TME conditions on regulation of the Na+/H+ exchanger NHE1, Ser/Thr kinases Akt1-3, and downstream effectors in endothelial cells. METHODS Human umbilical vein endothelial cells (HUVEC) and Ea.hy926 endothelial cells were exposed to simulated TME (1% hypoxia, low serum, glucose, pH, high lactate) or 1% hypoxia for 24 or 48 h, with or without NHE1 inhibition or siRNA-mediated knockdown. mRNA and protein levels of NHE1, Akt1-3, and downstream effectors were assessed by qPCR and Western blotting, vascular endothelial growth factor (VEGF) release by ELISA, and motility by scratch assay. RESULTS Within 24 h, HIF-1α level and VEGF mRNA level were increased robustly by TME and modestly by hypoxia alone. The NHE1 mRNA level was decreased by both hypoxia and TME, and NHE1 protein was reduced by TME in Ea.hy926 cells. Akt1-3 mRNA was detected in HUVEC and Ea.hy926 cells, Akt1 most abundantly. Akt1 protein expression was reduced by TME yet unaffected by hypoxia, while Akt phosphorylation was increased by TME. The Akt loss was partly reversed by MCF-7 human breast cancer cell conditioned medium, suggesting that in vivo, the cancer cell secretome may compensate for adverse effects of TME on endothelial cells. TME, yet not hypoxia, reduced p70S6 kinase activity and ribosomal protein S6 phosphorylation and increased eIF2α phosphorylation, consistent with inhibition of protein translation. Finally, TME reduced Retinoblastoma protein phosphorylation and induced poly-ADP-ribose polymerase (PARP) cleavage consistent with inhibition of proliferation and induction of apoptosis. NHE1 knockdown, mimicking the effect of TME on NHE1 expression, reduced Ea.hy926 migration. TME effects on HIF-1α, VEGF, Akt, translation, proliferation or apoptosis markers were unaffected by NHE1 knockdown/inhibition. CONCLUSIONS NHE1 and Akt are downregulated by TME conditions, more potently than by hypoxia alone. This inhibits endothelial cell migration and growth in a manner likely modulated by the cancer cell secretome.
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Affiliation(s)
- A K Pedersen
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - J Mendes Lopes de Melo
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - N Mørup
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - K Tritsaris
- Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Panum Institute, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
| | - S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, 2100, Copenhagen, Denmark.
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Stock C, Pedersen SF. Roles of pH and the Na +/H + exchanger NHE1 in cancer: From cell biology and animal models to an emerging translational perspective? Semin Cancer Biol 2016; 43:5-16. [PMID: 28007556 DOI: 10.1016/j.semcancer.2016.12.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 12/10/2016] [Indexed: 01/30/2023]
Abstract
Acidosis is characteristic of the solid tumor microenvironment. Tumor cells, because they are highly proliferative and anabolic, have greatly elevated metabolic acid production. To sustain a normal cytosolic pH homeostasis they therefore need to either extrude excess protons or to neutralize them by importing HCO3-, in both cases causing extracellular acidification in the poorly perfused tissue microenvironment. The Na+/H+ exchanger isoform 1 (NHE1) is a ubiquitously expressed acid-extruding membrane transport protein, and upregulation of its expression and/or activity is commonly correlated with tumor malignancy. The present review discusses current evidence on how altered pH homeostasis, and in particular NHE1, contributes to tumor cell motility, invasion, proliferation, and growth and facilitates evasion of chemotherapeutic cell death. We summarize data from in vitro studies, 2D-, 3D- and organotypic cell culture, animal models and human tissue, which collectively point to pH-regulation in general, and NHE1 in particular, as potential targets in combination chemotherapy. Finally, we discuss the possible pitfalls, side effects and cellular escape mechanisms that need to be considered in the process of translating the plethora of basic research data into a clinical setting.
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Affiliation(s)
- Christian Stock
- Department of Gastroenterology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
| | - Stine Falsig Pedersen
- Department of Biology, Section for Cell Biology and Physiology, University of Copenhagen, Universitetsparken 13, 2100 Copenhagen, Denmark.
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Andersen AP, Flinck M, Oernbo EK, Pedersen NB, Viuff BM, Pedersen SF. Roles of acid-extruding ion transporters in regulation of breast cancer cell growth in a 3-dimensional microenvironment. Mol Cancer 2016; 15:45. [PMID: 27266704 PMCID: PMC4896021 DOI: 10.1186/s12943-016-0528-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 05/20/2016] [Indexed: 12/20/2022] Open
Abstract
Background The 3-dimensional (3D) microenvironment of breast carcinomas is characterized by profoundly altered pH homeostasis, reflecting increased metabolic acid production and a confined extracellular space characterized by poor diffusion, yet the relative contributions of specific pH-regulatory transporters to 3D growth are poorly understood. The aim of this work was to determine how 3D spheroid growth of breast cancer cells impacts the expression and spatial organization of major acid extruding proteins, and how these proteins in turn are required for spheroid growth. Methods MCF-7 (Luminal-A) and MDA-MB-231 (Triple-negative) human breast cancer cells were grown as ~700-950 μm diameter spheroids, which were subjected to Western blotting for relevant transporters (2- and 3D growth), quantitative immunohistochemical analysis, and spheroid growth assays. Individual transporter contributions were assessed (i) pharmacologically, (ii) by stable shRNA- and transient siRNA-mediated knockdown, and (iii) by CRISPR/Cas9 knockout. Results In MCF-7 spheroids, expression of the lactate-H+ cotransporter MCT1 (SLC16A1) increased from the spheroid periphery to its core, the Na+,HCO3− cotransporter NBCn1 (SLC4A7) was most highly expressed at the periphery, and the Na+/H+ exchanger NHE1 (SLC9A1) and MCT4 (SLC16A3) were evenly distributed. A similar pattern was seen in MDA-MB-231 spheroids, except that these cells do not express MCT1. The relative total expression of NBCn1 and NHE1 was decreased in 3D compared to 2D, while that of MCT1 and MCT4 was unaltered. Inhibition of MCT1 (AR-C155858) attenuated MCF-7 spheroid growth and this was exacerbated by addition of S0859, an inhibitor of Na+,HCO3− cotransporters and MCTs. The pharmacological data was recapitulated by stable knockdown of MCT1 or NBCn1, whereas knockdown of MCT4 had no effect. CRISPR/Cas9 knockout of NHE1, but neither partial NHE1 knockdown nor the NHE1 inhibitor cariporide, inhibited MCF-7 spheroid growth. In contrast, growth of MDA-MB-231 spheroids was inhibited by stable or transient NHE1 knockdown and by NHE1 knockout, but not by knockdown of NBCn1 or MCT4. Conclusions This work demonstrates the distinct expression and localization patterns of four major acid-extruding transporters in 3D spheroids of human breast cancer cells and reveals that 3D growth is dependent on these transporters in a cell type-dependent manner, with potentially important implications for breast cancer therapy. Electronic supplementary material The online version of this article (doi:10.1186/s12943-016-0528-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Anne Poder Andersen
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Mette Flinck
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Eva Kjer Oernbo
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Nis Borbye Pedersen
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark
| | - Birgitte Martine Viuff
- Department of Veterinary Disease Biology, Section for Molecular Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Strandboulevarden 49, DK-2100, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Department of Biology, Section for Cell Biology and Physiology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
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Giannuzzo A, Pedersen SF, Novak I. The P2X7 receptor regulates cell survival, migration and invasion of pancreatic ductal adenocarcinoma cells. Mol Cancer 2015; 14:203. [PMID: 26607222 PMCID: PMC4660609 DOI: 10.1186/s12943-015-0472-4] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 11/18/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is presently one of the cancers with the worst survival rates and least effective treatments. Moreover, total deaths due to PDAC are predicted to increase in the next 15 years. Therefore, novel insights into basic mechanism of PDAC development and therapies are needed. PDAC is characterized by a complex microenvironment, in which cancer and stromal cells release different molecules, such as ATP. ATP can be transported and/or exocytosed from active cancer cells and released from dying cells in the necrotic core of the cancer. We hypothesized that one of the ATP receptors, the P2X7 receptor (P2X7R) could be an important player in PDAC behaviour. METHODS We determined the expression (real time PCR and Western blot) and localization (immunofluorescence) of P2X7R in human PDAC cell lines (AsPC-1, BxPC-3, Capan-1, MiaPaCa-2, Panc-1) and a "normal" human pancreatic duct epithelial cell line (HPDE). The function of P2X7R in proliferation (BrdU assay), migration (wound assay) and invasion (Boyden chamber with matrigel) was characterized. Furthermore, we studied P2X7R-dependent pore formation (YoPro-1 assay) and cell death (caspase and annexin V / propidium iodide assays). RESULTS We found higher expression of P2X7R protein in PDAC compared to HPDE cells. P2X7R had notable disparate effects on PDAC survival. Firstly, high concentrations of ATP or the specific P2X7R agonist, BzATP, had cytotoxic effects in all cell lines, and cell death was mediated by necrosis. Moreover, the P2X7R-pore antagonist, A438079, prevented ATP-induced pore formation and cell death. Second, in basal conditions and with low concentrations of ATP/BzATP, the P2X7R allosteric inhibitor AZ10606120 reduced proliferation in all PDAC cell lines. P2X7R also affected other key characteristics of cancer cell behavior. AZ10606120 reduced cell migration and invasion in PDAC cell lines compared to that of untreated/vehicle-treated control cells, and stimulation with sub-millimolar concentrations of ATP or BzATP substantially increased cell invasion. CONCLUSIONS PDAC cell lines overexpress P2X7R and the receptor plays crucial roles in cell survival, migration and invasion. Therefore, we propose that drugs targeting P2X7R could be exploited in therapy of pancreatic cancer.
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Affiliation(s)
- Andrea Giannuzzo
- Department of Biology, Section of Cell Biology and Physiology, University of Copenhagen, August Krogh Building, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
| | - Stine Falsig Pedersen
- Department of Biology, Section of Cell Biology and Physiology, University of Copenhagen, August Krogh Building, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
| | - Ivana Novak
- Department of Biology, Section of Cell Biology and Physiology, University of Copenhagen, August Krogh Building, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
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Pedraz-Cuesta E, Christensen S, Jensen AA, Jensen NF, Bunch L, Romer MU, Brünner N, Stenvang J, Pedersen SF. The glutamate transport inhibitor DL-Threo-β-Benzyloxyaspartic acid (DL-TBOA) differentially affects SN38- and oxaliplatin-induced death of drug-resistant colorectal cancer cells. BMC Cancer 2015; 15:411. [PMID: 25981639 PMCID: PMC4445981 DOI: 10.1186/s12885-015-1405-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 04/29/2015] [Indexed: 11/10/2022] Open
Abstract
Background Colorectal cancer (CRC) is a leading cause of cancer death globally and new biomarkers and treatments are severely needed. Methods Here, we employed HCT116 and LoVo human CRC cells made resistant to either SN38 or oxaliplatin, to investigate whether altered expression of the high affinity glutamate transporters Solute Carrier (SLC)-1A1 and -1A3 (EAAT3, EAAT1) is associated with the resistant phenotypes. Analyses included real-time quantitative PCR, immunoblotting and immunofluorescence analyses, radioactive tracer flux measurements, and biochemical analyses of cell viability and glutathione content. Results were evaluated using one- and two-way ANOVA and Students two-tailed t-test, as relevant. Results In SN38-resistant HCT116 and LoVo cells, SLC1A1 expression was down-regulated ~60 % and up-regulated ~4-fold, respectively, at both mRNA and protein level, whereas SLC1A3 protein was undetectable. The changes in SLC1A1 expression were accompanied by parallel changes in DL-Threo-β-Benzyloxyaspartic acid (TBOA)-sensitive, UCPH101-insensitive [3H]-D-Aspartate uptake, consistent with increased activity of SLC1A1 (or other family members), yet not of SLC1A3. DL-TBOA co-treatment concentration-dependently augmented loss of cell viability induced by SN38, while strongly counteracting that induced by oxaliplatin, in both HCT116 and LoVo cells. This reflected neither altered expression of the oxaliplatin transporter Cu2+-transporter-1 (CTR1), nor changes in cellular reduced glutathione (GSH), although HCT116 cell resistance per se correlated with increased cellular GSH. DL-TBOA did not significantly alter cellular levels of p21, cleaved PARP-1, or phospho-Retinoblastoma protein, yet altered SLC1A1 subcellular localization, and reduced chemotherapy-induced p53 induction. Conclusions SLC1A1 expression and glutamate transporter activity are altered in SN38-resistant CRC cells. Importantly, the non-selective glutamate transporter inhibitor DL-TBOA reduces chemotherapy-induced p53 induction and augments CRC cell death induced by SN38, while attenuating that induced by oxaliplatin. These findings may point to novel treatment options in treatment-resistant CRC. Electronic supplementary material The online version of this article (doi:10.1186/s12885-015-1405-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Elena Pedraz-Cuesta
- Department of Biology, Faculty of Science, University of Copenhagen, 13, Universitetsparken, DK-2100, Copenhagen, Denmark.
| | - Sandra Christensen
- Department of Biology, Faculty of Science, University of Copenhagen, 13, Universitetsparken, DK-2100, Copenhagen, Denmark.
| | - Anders A Jensen
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, 13, Universitetsparken, DK-2100, Copenhagen, Denmark.
| | - Niels Frank Jensen
- Faculty of Health and Medical Sciences, Institute of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Lennart Bunch
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, 13, Universitetsparken, DK-2100, Copenhagen, Denmark.
| | - Maria Unni Romer
- Faculty of Health and Medical Sciences, Institute of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark. .,Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
| | - Nils Brünner
- Faculty of Health and Medical Sciences, Institute of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Jan Stenvang
- Faculty of Health and Medical Sciences, Institute of Veterinary Disease Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Stine Falsig Pedersen
- Department of Biology, Faculty of Science, University of Copenhagen, 13, Universitetsparken, DK-2100, Copenhagen, Denmark.
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Kong SC, Giannuzzo A, Novak I, Pedersen SF. Corrigendum: Acid-base transport in pancreatic cancer: Molecular mechanisms and clinical potential. Biochem Cell Biol 2015; 93:272. [PMID: 25741778 DOI: 10.1139/bcb-2015-0026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Su Chii Kong
- Section for Cell and Developmental Biology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100 Copenhagen, Denmark
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Rasmussen LJH, Müller HSH, Jørgensen B, Pedersen SF, Hoffmann EK. Osmotic shrinkage elicits FAK- and Src phosphorylation and Src-dependent NKCC1 activation in NIH3T3 cells. Am J Physiol Cell Physiol 2014; 308:C101-10. [PMID: 25377086 DOI: 10.1152/ajpcell.00070.2014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The mechanisms linking cell volume sensing to volume regulation in mammalian cells remain incompletely understood. Here, we test the hypothesis that activation of nonreceptor tyrosine kinases Src, focal adhesion kinase (FAK), and Janus kinase-2 (Jak2) occurs after osmotic shrinkage of NIH3T3 fibroblasts and contributes to volume regulation by activation of NKCC1. FAK phosphorylation at Tyr397, Tyr576/577, and Tyr861 was increased rapidly after exposure to hypertonic (575 mOsm) saline, peaking after 10 (Tyr397, Tyr576/577) and 10-30 min (Tyr861). Shrinkage-induced Src family kinase autophosphorylation (pTyr416-Src) was induced after 2-10 min, and immunoprecipitation indicated that this reflected phosphorylation of Src itself, rather than Fyn and Yes. Phosphorylated Src and FAK partly colocalized with vinculin, a focal adhesion marker, after hypertonic shrinkage. The Src inhibitor pyrazolopyrimidine-2 (PP2, 10 μM) essentially abolished shrinkage-induced FAK phosphorylation at Tyr576/577 and Tyr861, yet not at Tyr397, and inhibited shrinkage-induced NKCC1 activity by ∼50%. The FAK inhibitor PF-573,228 augmented shrinkage-induced Src phosphorylation, and inhibited shrinkage-induced NKCC1 activity by ∼15%. The apparent role of Src in NKCC1 activation did not reflect phosphorylation of myosin light chain kinase (MLC), which was unaffected by shrinkage and by PP2, but may involve Jak2, a known target of Src, which was rapidly activated by osmotic shrinkage and inhibited by PP2. Collectively, our findings suggest a major role for Src and possibly the Jak2 axis in shrinkage-activation of NKCC1 in NIH3T3 cells, whereas no evidence was found for major roles for FAK and MLC in this process.
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Affiliation(s)
| | | | - Bente Jørgensen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Else Kay Hoffmann
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
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Sauter DRP, Novak I, Pedersen SF, Larsen EH, Hoffmann EK. ANO1 (TMEM16A) in pancreatic ductal adenocarcinoma (PDAC). Pflugers Arch 2014; 467:1495-1508. [PMID: 25163766 PMCID: PMC4464647 DOI: 10.1007/s00424-014-1598-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 07/22/2014] [Accepted: 08/11/2014] [Indexed: 12/31/2022]
Abstract
Pancreatic ductal adenocarcinoma (PDAC) has one of the worst survival rates of all cancers. ANO1 (TMEM16A) is a recently identified Ca2+-activated Cl− channel (CaCC) that is upregulated in several tumors. Although ANO1 was subject to extensive studies in the recent years, its pathophysiological function has only been poorly understood. The aim of the present study is to establish the significance of ANO1 in PDAC behavior and demarcate its roles in PDAC from those of the volume-regulated anion channel (VRAC). We performed qPCR and Western blot measurements on different PDAC cell lines (Panc-1, Mia PaCa 2, Capan-1, AsPC-1, BxPC-3) and compared the results to those obtained in a human pancreatic ductal epithelium (HPDE) cell line. All cancer cell lines showed an upregulation of ANO1 on mRNA and protein levels. Whole-cell patch-clamp recordings identified large Ca2+ and voltage-dependent Cl− currents in PDAC cells. Using siRNA knockdown of ANO1 and three ANO1 inhibitors (T16Ainh-A01, CaCCinh-A01, and NS3728), we found that ANO1 is the main constituent of CaCC current in PDAC cells. We further characterized these three inhibitors and found that they had unspecific effects on the free intracellular calcium concentration. Functional studies on PDAC behavior showed that surprisingly inhibition of ANO1 did not influence cellular proliferation. On the other hand, we found ANO1 channel to be pivotal in PDAC cell migration as assessed in wound healing experiments.
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Affiliation(s)
- D R P Sauter
- Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, August Krogh Building, Universitetsparken 13, 2100, Copenhagen Ø, Denmark.
| | - I Novak
- Section for Molecular Integrative Physiology, Department of Biology, University of Copenhagen, August Krogh Building, Universitetsparken 13, 2100 Copenhagen Ø, Denmark
| | - S F Pedersen
- Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, August Krogh Building, Universitetsparken 13, 2100, Copenhagen Ø, Denmark
| | - E H Larsen
- Section for Molecular Integrative Physiology, Department of Biology, University of Copenhagen, August Krogh Building, Universitetsparken 13, 2100 Copenhagen Ø, Denmark
| | - E K Hoffmann
- Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, August Krogh Building, Universitetsparken 13, 2100, Copenhagen Ø, Denmark
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Kong SC, Giannuzzo A, Gianuzzo A, Novak I, Pedersen SF. Acid-base transport in pancreatic cancer: molecular mechanisms and clinical potential. Biochem Cell Biol 2014; 92:449-59. [PMID: 25372771 DOI: 10.1139/bcb-2014-0078] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Solid tumors are characterized by a microenvironment that is highly acidic, while intracellular pH (pHi) is normal or even elevated. This is the result of elevated metabolic rates in the highly proliferative cancer cells, in conjunction with often greatly increased rates of net cellular acid extrusion. Studies in various cancers have suggested that while the acid extrusion mechanisms employed are generally the same as those in healthy cells, the specific transporters upregulated vary with the cancer type. The main such transporters include Na(+)/H(+) exchangers, various HCO3(-) transporters, H(+) pumps, and lactate-H(+) cotransporters. The mechanisms leading to their dysregulation in cancer are incompletely understood but include changes in transporter expression levels, trafficking and membrane localization, and posttranslational modifications. In turn, accumulating evidence has revealed that in addition to supporting their elevated metabolic rate, their increased acid efflux capacity endows the cancer cells with increased capacity for invasiveness, proliferation, and chemotherapy resistance. The pancreatic duct exhibits an enormous capacity for acid-base transport, rendering pHi dysregulation a potentially very important topic in pancreatic ductal adenocarcinoma (PDAC). PDAC - accounting for about 90% of all pancreatic cancers - has one of the highest cancer mortality rates known, and new diagnostic and treatment options are highly needed. However, very little is known about whether pH regulation is altered in PDAC and, if so, the possible role of this in cancer development. Here, we review current models for pancreatic acid-base transport and pH homeostasis and summarize current views on acid-base dysregulation in cancer, focusing where possible on the few studies to date in PDAC. Finally, we present new data-mining analyses of acid-base transporter expression changes in PDAC and discuss essential directions for future work.
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Affiliation(s)
- Su Chii Kong
- a Section for Cell and Developmental Biology, Department of Biology, Faculty of Science, University of Copenhagen, Universitetsparken 13, DK-2100 Copenhagen, Denmark
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Andersen AP, Moreira JMA, Pedersen SF. Interactions of ion transporters and channels with cancer cell metabolism and the tumour microenvironment. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130098. [PMID: 24493746 DOI: 10.1098/rstb.2013.0098] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Major changes in intra- and extracellular pH homoeostasis are shared features of most solid tumours. These changes stem in large part from the metabolic shift of most cancer cells towards glycolytic metabolism and other processes associated with net acid production. In combination with oncogenic signalling and impact from factors in the tumour microenvironment, this upregulates acid-extruding plasma membrane transport proteins which maintain intracellular pH normal or even more alkaline compared with that of normal cells, while in turn acidifying the external microenvironment. Mounting evidence strongly indicates that this contributes significantly to cancer development by favouring e.g. cancer cell migration, invasion and chemotherapy resistance. Finally, while still under-explored, it seems likely that non-cancer cells in the tumour microenvironment also exhibit altered pH regulation and that this may contribute to their malignant properties. Thus, the physical tumour microenvironment and the cancer and stromal cells within it undergo important reciprocal interactions which modulate the tumour pH profile, in turn severely impacting on the course of cancer progression. Here, we summarize recent knowledge of tumour metabolism and the tumour microenvironment, placing it in the context of tumour pH regulation, and discuss how interfering with these properties may be exploited clinically.
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Affiliation(s)
- Anne Poder Andersen
- Department of Biology, Faculty of Science, University of Copenhagen, Denmark
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31
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Abstract
Mammalian Na⁺/H⁺ exchangers of the SLC9A family are widely expressed and involved in numerous essential physiological processes. Their primary function is to mediate the 1:1 exchange of Na⁺ for H⁺ across the membrane in which they reside, and they play central roles in regulation of body, cellular, and organellar pH. Their function is tightly regulated through mechanisms involving interactions with multiple protein and lipid-binding partners, phosphorylations, and other posttranslational modifications. Biochemical and mutational analyses indicate that the SLC9As have a short intracellular N-terminus, 12 transmembrane (TM) helices necessary and sufficient for ion transport, and a C-terminal cytoplasmic tail region with essential regulatory roles. No high-resolution structures of the SLC9As exist; however, models based on crystal structures of the bacterial NhaAs support the 12 TM organization and suggest that TMIV and XI may form a central part of the ion-translocation pathway, whereas pH sensing may involve TMII, TMIX, and several intracellular loops. Similar to most ion transporters studied, SLC9As likely exist as coupled dimers in the membrane, and this appears to be important for the well-studied cooperativity of H⁺ binding. The aim of this work is to summarize and critically discuss the currently available evidence on the structural dynamics, regulation, and binding partner interactions of SLC9As, focusing in particular on the most widely studied isoform, SLC9A1/NHE1. Further, novel bioinformatic and structural analyses are provided that to some extent challenge the existing paradigm on how ions are transported by mammalian SLC9As.
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Affiliation(s)
- Ruth Hendus-Altenburger
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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Klausen TK, Janssens A, Prenen J, Owsianik G, Hoffmann EK, Pedersen SF, Nilius B. Single point mutations of aromatic residues in transmembrane helices 5 and -6 differentially affect TRPV4 activation by 4α-PDD and hypotonicity: implications for the role of the pore region in regulating TRPV4 activity. Cell Calcium 2013; 55:38-47. [PMID: 24342753 DOI: 10.1016/j.ceca.2013.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Accepted: 11/08/2013] [Indexed: 12/20/2022]
Abstract
The importance of the TRPV4 channel for human physiology has been highlighted in recent years with the identification of an increasing number of hereditary diseases associated with mutations of this channel. However, the functional understanding of TRPV4 associated pathologies remains a puzzle due to incomplete understanding of the polymodal regulation of TRPV4 channels and lack of insight into the structure-function relationship of the channel. In this work, we identified a series of highly conserved aromatic residues in transmembrane (TM) helices 5-6 with profound importance for TRPV4 activity. Substituting F617, Y621 or F624 in TM5 with leucine reduced channel sensitivity to the agonist 4α-PDD and heat, yet two of these mutants - F617L and Y621L - showed increased activation in response to cell swelling. In TM6, a Y702L mutation significantly reduced sensitivity to all of the above stimuli. In conclusion, we have identified residues in TM5-6 which differentially affect heat and agonist activation, and we have demonstrated distinct activation pathways for 4α-PDD and osmolarity.
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Affiliation(s)
- Thomas Kjær Klausen
- KU Leuven, Department of Cellular and Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Herestraat 49, Bus 802, Leuven, Belgium; Department of Biology, The August Krogh Building, Universitetsparken 13, DK-2100 Copenhagen Ø, Denmark.
| | - Annelies Janssens
- KU Leuven, Department of Cellular and Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Herestraat 49, Bus 802, Leuven, Belgium
| | - Jean Prenen
- KU Leuven, Department of Cellular and Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Herestraat 49, Bus 802, Leuven, Belgium
| | - Grzegorz Owsianik
- KU Leuven, Department of Cellular and Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Herestraat 49, Bus 802, Leuven, Belgium
| | - Else Kay Hoffmann
- Department of Biology, The August Krogh Building, Universitetsparken 13, DK-2100 Copenhagen Ø, Denmark
| | - Stine Falsig Pedersen
- Department of Biology, The August Krogh Building, Universitetsparken 13, DK-2100 Copenhagen Ø, Denmark
| | - Bernd Nilius
- KU Leuven, Department of Cellular and Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Herestraat 49, Bus 802, Leuven, Belgium
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33
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Stemann JH, Lauritzen G, Schröder JM, Pedersen SF. Novel potential binding partners of the C‐terminal tail of the sodium bicarbonate cotransporter NBCn1. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.730.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Gitte Lauritzen
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
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Andersen AP, Ronnov‐Jessen L, Hulikova A, Swietach P, Pedersen SF. Development of model systems for analysis of effects of cell‐cell and cell‐microenvironment interactions on pH regulatory proteins in breast cancer. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.471.4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Alzbeta Hulikova
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
| | - Pawel Swietach
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
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35
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Affiliation(s)
- Su Chii Kong
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | | | | | - Ivana Novak
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
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36
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Sigurđsson HH, Olesen CW, Dybboe R, Lauritzen G, Pedersen SF. Cisplatin‐induced cell death in MCF‐7 breast cancer cells: Roles of ΔNErbB2 and pH regulatory ion transporters NHE1 and NBCn1. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.727.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Rie Dybboe
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Gitte Lauritzen
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
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37
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Pedersen SF. Regulation of cell motility by Na+/H+ exchanger NHE1: implications for cancer development. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1145.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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38
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Gorbatenko A, Olesen C, Valen E, Pedersen SF. Regulation of the Na+,HCO3‐ cotransporter NBCn1 (SLC4A7) by a constitutively active ErbB2 receptor in MCF‐7 breast cancer cells. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.471.5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Eivind Valen
- Department of Molecular and Cellular BiologyHarvard UniversityCambridgeMA
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39
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Roest GAB, Pedersen SF. ERM proteins colocalize with the Na+/H+ exchanger NHE1 in MCF‐7 breast cancer cell invadopodia and affect invadopodia number. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1145.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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40
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Christensen S, Jensen NF, Stoeckel JD, Belling KC, Romer MU, Gupta R, Brünner N, Pedersen SF, Stenvang J. Colorectal cancer cell lines made resistant to SN38‐and Oxaliplatin: Roles of altered ion transporter function in resistance? FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.lb452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Sandra Christensen
- Department of BiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Niels Frank Jensen
- Institute of Veterinary Disease BiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Johanne Danmark Stoeckel
- Institute of Veterinary Disease BiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Kirstine C Belling
- Center for Biological Sequence AnalysisInstitute for Systems BiologyTechnical University of DenmarkLyngbyDenmark
| | - Maria Unni Romer
- Institute of Veterinary Disease BiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Ramneek Gupta
- Center for Biological Sequence AnalysisInstitute for Systems BiologyTechnical University of DenmarkLyngbyDenmark
| | - Nils Brünner
- Institute of Veterinary Disease BiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Stine Falsig Pedersen
- Department of BiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Jan Stenvang
- Institute of Veterinary Disease BiologyFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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41
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Sauter DRP, Pedersen SF, Novak I, Larsen EH, Hoffmann EK. Cl− and K+ channels in human pancreatic ductal adenocarcinoma (PDAC) cells. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.913.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Ivana Novak
- BiologyUniversity of CopenhagenCopenhagenDenmark
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42
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Abstract
Over the last 15 years it has become increasingly clear that dysregulated expression, splicing, and/or function of ion channels and transporters (ICT) occur in all cancers. Being linked to the widely accepted hallmarks of cancer, ICTs represent novel therapeutic, diagnostic, and prognostic targets. To discuss the current status of the field, a colloquium on "Ion Transport and Cancer" was held, covering the roles of ICTs in cancer cell proliferation, apoptosis, motility, and invasion, and in both the generation of and the interaction of the cancer cells with the tumor environment. Additional sessions dealt with pancreatic ductal adenocarcinoma and transport protein-based therapeutic and diagnostic concepts. There was overall consensus that essential contributions of ICT dysregulation to the cancer process have been demonstrated. Future research should be directed toward further elucidating the mechanisms and developing therapeutic applications.
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Boedtkjer E, Bunch L, Pedersen SF. Physiology, pharmacology and pathophysiology of the pH regulatory transport proteins NHE1 and NBCn1: similarities, differences, and implications for cancer therapy. Curr Pharm Des 2012; 18:1345-71. [PMID: 22360557 DOI: 10.2174/138161212799504830] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 12/26/2011] [Indexed: 11/22/2022]
Abstract
The Na⁺/H⁺-exchanger 1, NHE1 (SLC9A1) and the electroneutral Na⁺,HCO₃⁻ cotransporter NBCn1 (SLC4A7) are coexpressed in a wide range of tissues. Under normal physiological conditions these transporters play an ostensibly similar role, namely that of net acid extrusion after cellular acidification. In addition, they have been implicated in multiple other cellular processes, including regulation of transepithelial transport, cell volume, cell death/survival balance, and cell motility. In spite of their apparent functional similarity, the two transporters also serve distinctly different functions and are differentially regulated. Here, we provide an update on the basic structure, function, regulation, physiology and pharmacology of NHE1 and NBCn1, with particular focus on the factors responsible for their functional similarities and differences. Finally, we highlight recent findings implicating these transporters in cancer development, and discuss issues relating to NHE1 and NBCn1 as potential targets in cancer treatment.
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Affiliation(s)
- E Boedtkjer
- Department of Biomedicine, Ole Worms Allé 6, Building 1180, Aarhus University, DK-8000 Aarhus C, Denmark
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Madsen CP, Klausen TK, Fabian A, Hansen BJ, Pedersen SF, Hoffmann EK. On the role of TRPC1 in control of Ca2+ influx, cell volume, and cell cycle. Am J Physiol Cell Physiol 2012; 303:C625-34. [PMID: 22744003 DOI: 10.1152/ajpcell.00287.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca(+) signaling plays a crucial role in control of cell cycle progression, but the understanding of the dynamics of Ca(2+) influx and release of Ca(2+) from intracellular stores during the cell cycle is far from complete. The aim of the present study was to investigate the role of the free extracellular Ca(2+) concentration ([Ca(2+)](o)) in cell proliferation, the pattern of changes in the free intracellular Ca(2+) concentration ([Ca(2+)](i)) during cell cycle progression, and the role of the transient receptor potential (TRP)C1 in these changes as well as in cell cycle progression and cell volume regulation. In Ehrlich Lettré Ascites (ELA) cells, [Ca(2+)](i) decreased significantly, and the thapsigargin-releasable Ca(2+) pool in the intracellular stores increased in G(1) as compared with G(0). Store-depletion-operated Ca(2+) entry (SOCE) and TRPC1 protein expression level were both higher in G(1) than in G(0) and S phase, in parallel with a more effective volume regulation after swelling [regulatory volume decrease (RVD)] in G(1) as compared with S phase. Furthermore, reduction of [Ca(2+)](o), as well as two unspecific SOCE inhibitors, 2-APB (2-aminoethyldiphenyl borinate) and SKF96365 (1-(β-[3-(4-methoxy-phenyl)propoxyl-4-methoxyphenethyl)1H-imidazole-hydrochloride), inhibited ELA cell proliferation. Finally, Madin-Darby canine kidney cells in which TRPC1 was stably silenced [TRPC1 knockdown (TRPC1-KD) MDCK] exhibited reduced SOCE, slower RVD, and reduced cell proliferation compared with mock controls. In conclusion, in ELA cells, SOCE and TRPC1 both seem to be upregulated in G(1) as compared with S phase, concomitant with an increased rate of RVD. Furthermore, TRPC1-KD MDCK cells exhibit decreased SOCE, decreased RVD, and decreased proliferation, suggesting that, at least in certain cell types, TRPC1 is regulated during cell cycle progression and is involved in SOCE, RVD, and cell proliferation.
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Affiliation(s)
- C P Madsen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
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45
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Lauritzen G, Stock CM, Lemaire J, Lund SF, Jensen MF, Damsgaard B, Petersen KS, Wiwel M, Rønnov-Jessen L, Schwab A, Pedersen SF. The Na+/H+ exchanger NHE1, but not the Na+, cotransporter NBCn1, regulates motility of MCF7 breast cancer cells expressing constitutively active ErbB2. Cancer Lett 2012; 317:172-83. [DOI: 10.1016/j.canlet.2011.11.023] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 11/16/2011] [Accepted: 11/17/2011] [Indexed: 12/14/2022]
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46
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Gorbatenko A, Olesen CW, Lauritzen G, Valen E, Pedersen SF. Regulation of the Na, HCO3‐cotransporter NBCn1 (SLC4A7) by a constitutively active ErbB2 receptor in MCF‐7 breast cancer cells. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.882.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Gitte Lauritzen
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Evind Valen
- Department of BiologyUniversity of CopenhagenCopenhagenDenmark
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47
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Andersen AP, Ronnov-Jessen L, Hulikova A, Swietach P, Pedersen SF. Development of complex model systems for analysis of cell‐cell and cell‐microenvironment interactions in breast cancer. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1064.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Alzbeta Hulikova
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
| | - Pawel Swietach
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUnited Kingdom
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48
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Gorbatenko A, Wiwel M, Klingberg H, Nielsen AB, Kapus A, Pedersen SF. Hyperosmotic stress strongly potentiates serum response factor (SRF)-dependent transcriptional activity in Ehrlich Lettré Ascites cells through a mechanism involving p38 mitogen-activated protein kinase. J Cell Physiol 2011; 226:2857-68. [PMID: 21302281 DOI: 10.1002/jcp.22628] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Long-term osmotic stress results in altered gene transcription, however, with the exception of the TonE/TonEBP system, the underlying mechanisms are poorly understood. We previously showed that upon osmotic shrinkage of Ehrlich Lettré Ascites (ELA) fibroblasts, the MEK1-ERK1/2 pathway is transiently inhibited while p38 MAPK is activated, in turn impacting on cell survival (Pedersen et al., 2007, Cell Physiol Biochem 20: 735-750). Here, we show that downstream of these kinases, two transcription factors with major roles in control of cell proliferation and death, serum response factor (SRF) and cAMP response element-binding protein (CREB) are differentially regulated in ELA cells. SRF Ser(103) phosphorylation and SRF-dependent transcriptional activity were strongly augmented 5-30 min and 24 h, respectively, after hyperosmotic stress (50% increase in extracellular ionic strength), in a p38 MAPK-dependent manner. In contrast, CREB Ser(133) was transiently dephosphorylated upon osmotic shrinkage. The ERK1/2 effector ribosomal S kinase (RSK) and the ERK1/2- and p38 MAPK effector mitogen- stress-activated protein kinase 1 (MSK1) both phosphorylate CREB at Ser(133) . RSK and MSK1 were dephosphorylated within 5 min of shrinkage. MSK1 phosphorylation recovered within 30 min in a p38-MAPK-dependent manner. CREB was transiently dephosphorylated after shrinkage in a manner exacerbated by p38 MAPK inhibition or MSK1 knockdown, but unaffected by inhibition of RSK. In conclusion, in ELA cells, hyperosmotic stress activates SRF in a p38 MAPK-dependent manner and transiently inactivates CREB, likely due to MSK1 inactivation. We suggest that these events contribute to shrinkage-induced changes in gene transcription and death/survival balance.
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Affiliation(s)
- Andrej Gorbatenko
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
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49
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Abstract
Perturbations of cellular and systemic osmolarity severely challenge the function of all organisms and are consequently regulated very tightly. Here we outline current evidence on how cells sense volume perturbations, with particular focus on mechanisms relevant to the kidneys and to extracellular osmolarity and whole body volume homeostasis. There are a variety of molecular signals that respond to perturbations in cell volume and osmosensors or volume sensors responding to these signals. The early signals of volume perturbation include integrins, the cytoskeleton, receptor tyrosine kinases, and transient receptor potential channels. We also present current evidence on the localization and function of central and peripheral systemic osmosensors and conclude with a brief look at the still limited evidence on pathophysiological conditions associated with deranged sensing of cell volume.
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Affiliation(s)
- Stine Falsig Pedersen
- Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100, Copenhagen, Denmark.
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50
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Abstract
Cell volume homeostasis and its fine-tuning to the specific physiological context at any given moment are processes fundamental to normal cell function. The understanding of cell volume regulation owes much to August Krogh, yet has advanced greatly over the last decades. In this review, we outline the historical context of studies of cell volume regulation, focusing on the lineage started by Krogh, Bodil Schmidt-Nielsen, Hans-Henrik Ussing, and their students. The early work was focused on understanding the functional behaviour, kinetics and thermodynamics of the volume-regulatory ion transport mechanisms. Later work addressed the mechanisms through which cellular signalling pathways regulate the volume regulatory effectors or flux pathways. These studies were facilitated by the molecular identification of most of the relevant channels and transporters, and more recently also by the increased understanding of their structures. Finally, much current research in the field focuses on the most up- and downstream components of these paths: how cells sense changes in cell volume, and how cell volume changes in turn regulate cell function under physiological and pathophysiological conditions.
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Affiliation(s)
- E K Hoffmann
- Section of Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
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