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Riemann A, Rauschner M, Gießelmann M, Reime S, Thews O. The Acidic Tumor Microenvironment Affects Epithelial-Mesenchymal Transition Markers as Well as Adhesion of NCI-H358 Lung Cancer Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1269:179-183. [PMID: 33966214 DOI: 10.1007/978-3-030-48238-1_28] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Epithelial-mesenchymal transition (EMT), which is involved in metastasis formation, requires reprogramming of gene expression mediated by key EMT transcription factors. However, signals from the cellular microenvironment, including hypoxia, can also modulate the process of EMT. Hypoxia is often associated with a reduction in the extracellular pH of the tumor microenvironment (acidosis). Whether acidosis alone has an impact on the expression of the EMT markers E-cadherin, N-cadherin, and vimentin was studied in NCI-H358 lung cancer cells. Reducing extracellular pH decreased E-cadherin mRNA, while vimentin and N-cadherin mRNA were doubled. However, at the protein level, E-cadherin and N-cadherin were both reduced, and only vimentin was upregulated. E-cadherin and N-cadherin expression at the cell surface, which is the relevant parameter for cell-cell and cell-matrix interaction, decreased too. The reduction of cell surface proteins was due to diminished protein expression and not changes in cellular localization, since localization of EMT markers in general was not affected by acidosis. Acidosis also affected NCI-H358 cells functionally. Adhesion was decreased when the cells were primed in an acidic medium before measuring cell adherence, which is in line with the reduced expression of cadherins at the cell surface. Additionally, migration was decreased after acidic priming. A possible mechanism for the regulation of EMT markers involves the action of microRNA-203a (miR-203a). In NCI-H358 lung cancer cells, miR-203a expression was repressed by acidosis. Since a decrease in the level of miR-203a has been shown to induce EMT, it might be involved in the modulation of EMT marker expression, adhesion, and migration by the acidic tumor microenvironment in NCI-H358 lung cancer cells.
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Affiliation(s)
- Anne Riemann
- Julius Bernstein Institute of Physiology, University of Halle-Wittenberg, Halle (Saale), Germany.
| | - M Rauschner
- Julius Bernstein Institute of Physiology, University of Halle-Wittenberg, Halle (Saale), Germany
| | - M Gießelmann
- Julius Bernstein Institute of Physiology, University of Halle-Wittenberg, Halle (Saale), Germany
| | - S Reime
- Julius Bernstein Institute of Physiology, University of Halle-Wittenberg, Halle (Saale), Germany
| | - O Thews
- Julius Bernstein Institute of Physiology, University of Halle-Wittenberg, Halle (Saale), Germany
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Extracellular Acidosis Modulates the Expression of Epithelial-Mesenchymal Transition (EMT) Markers and Adhesion of Epithelial and Tumor Cells. Neoplasia 2019; 21:450-458. [PMID: 30953950 PMCID: PMC6447725 DOI: 10.1016/j.neo.2019.03.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/04/2019] [Accepted: 03/07/2019] [Indexed: 12/12/2022] Open
Abstract
Epithelial-to-mesenchymal transition (EMT) is an important process of tumor progression associated with increased metastatic potential. EMT can be activated by external triggers such as cytokines or metabolic parameters (e.g. hypoxia). Since extracellular acidosis is a common finding in tumors, the aim of the study is to analyze its impact on the expression of EMT markers in vitro and in vivo as well as the functional impact on cell adhesion. Therefore, three tumor and two normal epithelial cell lines were incubated for 24 h at pH 6.6 and the expression of EMT markers was studied. In addition, mRNA expression of transcription and metabolic factors related to EMT was measured as well as the functional impact on cell adhesion, either during acidic incubation or after priming cells in an acidic milieu. E-cadherin and N-cadherin were down-regulated in all tumor and normal cell lines studied, whereas vimentin expression increased in only two tumor and one normal cell line. Down-regulation of the cadherins was seen in total protein and to a lesser extent in surface protein. In vivo an increase in N-cadherin and vimentin expression was found. Acidosis up-regulated Twist1 and Acsl1 but down-regulated fumarate hydratase (Fh). Cell adhesion during acidic incubation decreased in AT1 prostate carcinoma cells whereas preceding acidic priming increased their subsequent adhesion. Low tumor pH is able to modulate the expression EMT-related proteins and by this may affect the stability of the tissue structure.
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Wolf C, Weth A, Walcher S, Lax C, Baumgartner W. Modeling of Zinc Dynamics in the Synaptic Cleft: Implications for Cadherin Mediated Adhesion and Synaptic Plasticity. Front Mol Neurosci 2018; 11:306. [PMID: 30233309 PMCID: PMC6131644 DOI: 10.3389/fnmol.2018.00306] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 08/13/2018] [Indexed: 12/18/2022] Open
Abstract
While the numerous influences of synaptically released zinc on synaptic efficiency during long-term potentiation have been discussed by many authors already, we focused on the possible effect of zinc on cadherins and therefore its contribution to morphological changes in the context of synaptic plasticity. The difficulty with gaining insights into the dynamics of zinc-cadherin interaction is the inability to directly observe it on a suitable timescale. Therefore our approach was to establish an analytical model of the zinc diffusion dynamics in the synaptic cleft and experimentally validate, if the theoretical concentrations at the periphery of the synaptic cleft are sufficient to significantly modulate cadherin-mediated adhesion. Our results emphasize, that synaptically released zinc might have a strong accelerating effect on the morphological changes involved in long-term synaptic plasticity. The approach presented here might also prove useful for investigations on other synaptically released trace metals.
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Affiliation(s)
- Christoph Wolf
- Institute of Medical Biomechatronics, Johannes Kepler University Linz, Linz, Austria
| | - Agnes Weth
- Institute of Medical Biomechatronics, Johannes Kepler University Linz, Linz, Austria
| | | | - Christian Lax
- Lehrstuhl A für Mathematik, RWTH-Aachen University, Aachen, Germany
| | - Werner Baumgartner
- Institute of Medical Biomechatronics, Johannes Kepler University Linz, Linz, Austria
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Hofschröer V, Koch KA, Ludwig FT, Friedl P, Oberleithner H, Stock C, Schwab A. Extracellular protonation modulates cell-cell interaction mechanics and tissue invasion in human melanoma cells. Sci Rep 2017; 7:42369. [PMID: 28205573 PMCID: PMC5304230 DOI: 10.1038/srep42369] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 01/10/2017] [Indexed: 12/25/2022] Open
Abstract
Detachment of cells from the primary tumour precedes metastatic progression by
facilitating cell release into the tissue. Solid tumours exhibit altered pH
homeostasis with extracellular acidification. In human melanoma, the
Na+/H+ exchanger NHE1 is an important modifier of
the tumour nanoenvironment. Here we tested the modulation of cell-cell-adhesion by
extracellular pH and NHE1. MV3 tumour spheroids embedded in a collagen matrix
unravelled the efficacy of cell-cell contact loosening and 3D emigration into an
environment mimicking physiological confinement. Adhesive interaction strength
between individual MV3 cells was quantified using atomic force microscopy and
validated by multicellular aggregation assays. Extracellular acidification from
pHe7.4 to 6.4 decreases cell migration and invasion but increases
single cell detachment from the spheroids. Acidification and NHE1 overexpression
both reduce cell-cell adhesion strength, indicated by reduced maximum pulling forces
and adhesion energies. Multicellular aggregation and spheroid formation are strongly
impaired under acidification or NHE1 overexpression. We show a clear dependence of
melanoma cell-cell adhesion on pHe and NHE1 as a modulator. These effects
are opposite to cell-matrix interactions that are strengthened by protons extruded
via NHE1. We conclude that these opposite effects of NHE1 act synergistically during
the metastatic cascade.
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Affiliation(s)
| | | | | | - Peter Friedl
- Radboud University Medical Centre, Radboud Institute for Molecular Life Sciences, Department of Cell Biology, Nijmegen, The Netherlands.,David H. Koch Center for Applied Research of Genitourinary Cancers, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States.,Cancer Genomics Center, CG Utrecht, The Netherlands
| | | | - Christian Stock
- Department of Gastroenterology, Hannover Medical School, Hannover, Germany
| | - Albrecht Schwab
- Institute of Physiology II, University of Münster, Münster, Germany
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Weth A, Dippl C, Striedner Y, Tiemann-Boege I, Vereshchaga Y, Golenhofen N, Bartelt-Kirbach B, Baumgartner W. Water transport through the intestinal epithelial barrier under different osmotic conditions is dependent on LI-cadherin trans-interaction. Tissue Barriers 2017; 5:e1285390. [PMID: 28452574 PMCID: PMC5501135 DOI: 10.1080/21688370.2017.1285390] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
In the intestine water has to be reabsorbed from the chymus across the intestinal epithelium. The osmolarity within the lumen is subjected to high variations meaning that water transport often has to take place against osmotic gradients. It has been hypothesized that LI-cadherin is important in this process by keeping the intercellular cleft narrow facilitating the buildup of an osmotic gradient allowing water reabsorption. LI-cadherin is exceptional among the cadherin superfamily with respect to its localization along the lateral plasma membrane of epithelial cells being excluded from adherens junction. Furthermore it has 7 but not 5 extracellular cadherin repeats (EC1-EC7) and a small cytosolic domain. In this study we identified the peptide VAALD as an inhibitor of LI-cadherin trans-interaction by modeling the structure of LI-cadherin and comparison with the known adhesive interfaces of E-cadherin. This inhibitory peptide was used to measure LI-cadherin dependency of water transport through a monolayer of epithelial CACO2 cells under various osmotic conditions. If LI-cadherin trans-interaction was inhibited by use of the peptide, water transport from the luminal to the basolateral side was impaired and even reversed in the case of hypertonic conditions whereas no effect could be observed at isotonic conditions. These data are in line with a recently published model predicting LI-cadherin to keep the width of the lateral intercellular cleft small. In this narrow cleft a high osmolarity can be achieved due to ion pumps yielding a standing osmotic gradient allowing water absorption from the gut even if the faeces is highly hypertonic.
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Affiliation(s)
- Agnes Weth
- a Institute of Biomedical Mechatronics, Johannes Kepler University of Linz , Linz , Austria
| | - Carsten Dippl
- a Institute of Biomedical Mechatronics, Johannes Kepler University of Linz , Linz , Austria
| | - Yasmin Striedner
- b Institute of Biophysics, Johannes Kepler University of Linz , Linz , Austria
| | - Irene Tiemann-Boege
- b Institute of Biophysics, Johannes Kepler University of Linz , Linz , Austria
| | - Yana Vereshchaga
- a Institute of Biomedical Mechatronics, Johannes Kepler University of Linz , Linz , Austria
| | - Nikola Golenhofen
- c Institute of Anatomy and Cell Biology, University of Ulm , Ulm , Germany
| | | | - Werner Baumgartner
- a Institute of Biomedical Mechatronics, Johannes Kepler University of Linz , Linz , Austria
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Heiliger E, Osmanagic A, Haase H, Golenhofen N, Grabrucker AM, Weth A, Baumgartner W. N-cadherin-mediated cell adhesion is regulated by extracellular Zn2+. Metallomics 2015; 7:355-62. [DOI: 10.1039/c4mt00300d] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Free extracellular zinc binds to N-cadherin and can modulate cellular adhesion in the nervous system at picomolar zinc concentrations.
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Affiliation(s)
- E. Heiliger
- Department of Cellular Neurobionics
- RWTH-Aachen University
- 52074 Aachen, Germany
| | - A. Osmanagic
- Department of Cellular Neurobionics
- RWTH-Aachen University
- 52074 Aachen, Germany
| | - H. Haase
- Institute of Immunology
- RWTH-Aachen University
- 52074 Aachen, Germany
- Department of Food Chemistry and Toxicology
- Berlin Institute of Technology
| | - N. Golenhofen
- Institute of Anatomy and Cell Biology
- Ulm University
- Ulm, Germany
| | - A. M. Grabrucker
- Institute of Anatomy and Cell Biology
- Ulm University
- Ulm, Germany
- WG Molecular Analysis of Synaptopathies
- Neurology Dept
| | - A. Weth
- Institute of Biomedical Mechatronics
- Johannes Kepler University of Linz
- Linz, Austria
| | - W. Baumgartner
- Department of Cellular Neurobionics
- RWTH-Aachen University
- 52074 Aachen, Germany
- Institute of Biomedical Mechatronics
- Johannes Kepler University of Linz
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Baumgartner W, Weth A, Gutberlet J, Harms G, Groschner K. Localization of VE-cadherin in plasmalemmal cholesterol rich microdomains and the effects of cholesterol depletion on VE-cadherin mediated cell–cell adhesion. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1841:1725-32. [DOI: 10.1016/j.bbalip.2014.08.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Revised: 08/01/2014] [Accepted: 08/25/2014] [Indexed: 10/24/2022]
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Jungles JM, Dukes MP, Vunnam N, Pedigo S. Impact of pH on the structure and function of neural cadherin. Biochemistry 2014; 53:7436-44. [PMID: 25365402 DOI: 10.1021/bi5010798] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neural (N-) cadherin is a transmembrane protein within adherens junctions that mediates cell-cell adhesion. It has 5 modular extracellular domains (EC1-EC5) that bind 3 calcium ions between each of the modules. Calcium binding is required for dimerization. N-Cadherin is involved in diverse processes including tissue morphogenesis, excitatory synapse formation and dynamics, and metastasis of cancer. During neurotransmission and tumorigenesis, fluctuations in extracellular pH occur, causing tissue acidosis with associated physiological consequences. Studies reported here aim to determine the effect of pH on the dimerization properties of a truncated construct of N-cadherin containing EC1-EC2. Since N-cadherin is an anionic protein, we hypothesized that acidification of solution would cause an increase in stability of the apo protein, a decrease in the calcium-binding affinity, and a concomitant decrease in the formation of adhesive dimer. The stability of the apo monomer was increased and the calcium-binding affinity was decreased at reduced pH, consistent with our hypothesis. Surprisingly, analytical SEC studies showed an increase in calcium-induced dimerization as solution pH decreased from 7.4 to 5.0. Salt-dependent dimerization studies indicated that electrostatic repulsion attenuates dimerization affinity. These results point to a possible electrostatic mechanism for moderating dimerization affinity of the Type I cadherin family. Extrapolating these results to cell adhesion in vivo leads to the assertion that decreased pH promotes adhesion by N-cadherin, thereby stabilizing synaptic junctions.
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Affiliation(s)
- Jared M Jungles
- Department of Chemistry and Biochemistry, University of Mississippi , University, Mississippi 38677, United States
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Sedlakova O, Svastova E, Takacova M, Kopacek J, Pastorek J, Pastorekova S. Carbonic anhydrase IX, a hypoxia-induced catalytic component of the pH regulating machinery in tumors. Front Physiol 2014; 4:400. [PMID: 24409151 PMCID: PMC3884196 DOI: 10.3389/fphys.2013.00400] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 12/19/2013] [Indexed: 12/19/2022] Open
Abstract
Acidic tissue microenvironment contributes to tumor progression via multiple effects including the activation of angiogenic factors and proteases, reduced cell-cell adhesion, increased migration and invasion, etc. In addition, intratumoral acidosis can influence the uptake of anticancer drugs and modulate the response of tumors to conventional therapy. Acidification of the tumor microenvironment often develops due to hypoxia-triggered oncogenic metabolism, which leads to the extensive production of lactate, protons, and carbon dioxide. In order to avoid intracellular accumulation of the acidic metabolic products, which is incompatible with the survival and proliferation, tumor cells activate molecular machinery that regulates pH by driving transmembrane inside-out and outside-in ion fluxes. Carbonic anhydrase IX (CA IX) is a hypoxia-induced catalytic component of the bicarbonate import arm of this machinery. Through its catalytic activity, CA IX directly participates in many acidosis-induced features of tumor phenotype as demonstrated by manipulating its expression and/or by in vitro mutagenesis. CA IX can function as a survival factor protecting tumor cells from hypoxia and acidosis, as a pro-migratory factor facilitating cell movement and invasion, as a signaling molecule transducing extracellular signals to intracellular pathways (including major signaling and metabolic cascades) and converting intracellular signals to extracellular effects on adhesion, proteolysis, and other processes. These functional implications of CA IX in cancer are supported by numerous clinical studies demonstrating the association of CA IX with various clinical correlates and markers of aggressive tumor behavior. Although our understanding of the many faces of CA IX is still incomplete, existing knowledge supports the view that CA IX is a biologically and clinically relevant molecule, exploitable in anticancer strategies aimed at targeting adaptive responses to hypoxia and/or acidosis.
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Affiliation(s)
- Olga Sedlakova
- Department of Molecular Medicine, Institute of Virology, Slovak Academy of Sciences Bratislava, Slovakia
| | - Eliska Svastova
- Department of Molecular Medicine, Institute of Virology, Slovak Academy of Sciences Bratislava, Slovakia
| | - Martina Takacova
- Department of Molecular Medicine, Institute of Virology, Slovak Academy of Sciences Bratislava, Slovakia
| | - Juraj Kopacek
- Department of Molecular Medicine, Institute of Virology, Slovak Academy of Sciences Bratislava, Slovakia
| | - Jaromir Pastorek
- Department of Molecular Medicine, Institute of Virology, Slovak Academy of Sciences Bratislava, Slovakia
| | - Silvia Pastorekova
- Department of Molecular Medicine, Institute of Virology, Slovak Academy of Sciences Bratislava, Slovakia
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Gene expression profiling as a tool to investigate the molecular machinery activated during hippocampal neurodegeneration induced by trimethyltin (TMT) administration. Int J Mol Sci 2013; 14:16817-35. [PMID: 23955266 PMCID: PMC3759937 DOI: 10.3390/ijms140816817] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 08/06/2013] [Accepted: 08/08/2013] [Indexed: 12/31/2022] Open
Abstract
Trimethyltin (TMT) is an organotin compound exhibiting neurotoxicant effects selectively localized in the limbic system and especially marked in the hippocampus, in both experimental animal models and accidentally exposed humans. TMT administration causes selective neuronal death involving either the granular neurons of the dentate gyrus or the pyramidal cells of the Cornu Ammonis, with a different pattern of localization depending on the different species studied or the dosage schedule. TMT is broadly used to realize experimental models of hippocampal neurodegeneration associated with cognitive impairment and temporal lobe epilepsy, though the molecular mechanisms underlying the associated selective neuronal death are still not conclusively clarified. Experimental evidence indicates that TMT-induced neurodegeneration is a complex event involving different pathogenetic mechanisms, probably acting differently in animal and cell models, which include neuroinflammation, intracellular calcium overload, and oxidative stress. Microarray-based, genome-wide expression analysis has been used to investigate the molecular scenario occurring in the TMT-injured brain in different in vivo and in vitro models, producing an overwhelming amount of data. The aim of this review is to discuss and rationalize the state-of-the-art on TMT-associated genome wide expression profiles in order to identify comparable and reproducible data that may allow focusing on significantly involved pathways.
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