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Tittarelli A, Guerrero I, Tempio F, Gleisner MA, Avalos I, Sabanegh S, Ortíz C, Michea L, López MN, Mendoza-Naranjo A, Salazar-Onfray F. Overexpression of connexin 43 reduces melanoma proliferative and metastatic capacity. Br J Cancer 2015; 113:259-67. [PMID: 26135897 PMCID: PMC4506378 DOI: 10.1038/bjc.2015.162] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/18/2015] [Accepted: 04/21/2015] [Indexed: 01/14/2023] Open
Abstract
Background: Alterations in connexin 43 (Cx43) expression and/or gap junction (GJ)-mediated intercellular communication are implicated in cancer pathogenesis. Herein, we have investigated the role of Cx43 in melanoma cell proliferation and apoptosis sensitivity in vitro, as well as metastatic capability and tumour growth in vivo. Methods: Connexin 43 expression levels, GJ coupling and proliferation rates were analysed in four different human melanoma cell lines. Furthermore, tumour growth and lung metastasis of high compared with low Cx43-expressing FMS cells were evaluated in vivo using a melanoma xenograft model. Results: Specific inhibition of Cx43 channel activity accelerated melanoma cell proliferation, whereas overexpression of Cx43 increased GJ coupling and reduced cell growth. Moreover, Cx43 overexpression in FMS cells increased basal and tumour necrosis factor-α-induced apoptosis and resulted in decreased melanoma tumour growth and lower number and size of metastatic foci in vivo. Conclusions: Our findings reveal an important role for Cx43 in intrinsically controlling melanoma growth, death and metastasis, and emphasise the potential use of compounds that selectively enhance Cx43 expression on melanoma in the future chemotherapy and/or immunotherapy protocols.
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Affiliation(s)
- A Tittarelli
- Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile
| | - I Guerrero
- Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile
| | - F Tempio
- 1] Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile [2] Millennium Institute on Immunology and Immunotherapy, Institute of Biomedical Sciences, University of Chile, Santiago 8380453, Chile
| | - M A Gleisner
- Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile
| | - I Avalos
- Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile
| | - S Sabanegh
- Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile
| | - C Ortíz
- Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile
| | - L Michea
- 1] Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile [2] Millennium Institute on Immunology and Immunotherapy, Institute of Biomedical Sciences, University of Chile, Santiago 8380453, Chile
| | - M N López
- 1] Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile [2] Millennium Institute on Immunology and Immunotherapy, Institute of Biomedical Sciences, University of Chile, Santiago 8380453, Chile [3] Research Support Office, University of Chile Clinical Hospital, Santiago 8380453, Chile
| | - A Mendoza-Naranjo
- UCL Cancer Institute, University College London, 72 Huntley Street, London WC1E 6DD, UK
| | - F Salazar-Onfray
- 1] Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago 8380453, Chile [2] Millennium Institute on Immunology and Immunotherapy, Institute of Biomedical Sciences, University of Chile, Santiago 8380453, Chile
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Mendoza-Naranjo A, Cormie P, Serrano AE, Hu R, O'Neill S, Wang CM, Thrasivoulou C, Power KT, White A, Serena T, Phillips ARJ, Becker DL. Targeting Cx43 and N-cadherin, which are abnormally upregulated in venous leg ulcers, influences migration, adhesion and activation of Rho GTPases. PLoS One 2012; 7:e37374. [PMID: 22615994 PMCID: PMC3352877 DOI: 10.1371/journal.pone.0037374] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 04/18/2012] [Indexed: 12/19/2022] Open
Abstract
Background Venous leg ulcers can be very hard to heal and represent a significant medical need with no effective therapeutic treatment currently available. Principal Findings In wound edge biopsies from human venous leg ulcers we found a striking upregulation of dermal N-cadherin, Zonula Occludens-1 and the gap junction protein Connexin43 (Cx43) compared to intact skin, and in stark contrast to the down-regulation of Cx43 expression seen in acute, healing wounds. We targeted the expression of these proteins in 3T3 fibroblasts to evaluate their role in venous leg ulcers healing. Knockdown of Cx43 and N-cadherin, but not Zonula Occludens-1, accelerated cell migration in a scratch wound-healing assay. Reducing Cx43 increased Golgi reorientation, whilst decreasing cell adhesion and proliferation. Furthermore, Connexin43 and N-cadherin knockdown led to profound effects on fibroblast cytoskeletal dynamics after scratch-wounding. The cells exhibited longer lamelipodial protrusions lacking the F-actin belt seen at the leading edge in wounded control cells. This phenotype was accompanied by augmented activation of Rac-1 and RhoA GTPases, as revealed by Förster Resonance Energy Transfer and pull down experiments. Conclusions Cx43 and N-cadherin are potential therapeutic targets in the promotion of healing of venous leg ulcers, by acting at least in part through distinct contributions of cell adhesion, migration, proliferation and cytoskeletal dynamics.
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Affiliation(s)
- Ariadna Mendoza-Naranjo
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
- * E-mail: (DLB); (AMN)
| | - Peter Cormie
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Antonio E. Serrano
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Rebecca Hu
- CoDa Therapeutics, Auckland, New Zealand
| | | | - Chiuhui Mary Wang
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | | | - Kieran T. Power
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | | | - Thomas Serena
- Newbridge Medical Research Corp, Warren, Pennsylvania, United States of America
| | | | - David L. Becker
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
- * E-mail: (DLB); (AMN)
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Mende M, Christophorou NAD, Streit A. Specific and effective gene knock-down in early chick embryos using morpholinos but not pRFPRNAi vectors. Mech Dev 2008; 125:947-62. [PMID: 18801428 DOI: 10.1016/j.mod.2008.08.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2008] [Revised: 08/21/2008] [Accepted: 08/25/2008] [Indexed: 11/24/2022]
Abstract
In the chick embryo, two methods are now used for studying the developmental role of genes by loss-of-function approaches: vector-based shRNA and morpholino oligonucleotides. Both have the advantage that loss-of-function can be conducted in a spatially and temporally controlled way by focal electroporation. Here, we compare these two methods. We find that the shRNA expressing vectors pRFPRNAi, even when targeting a non-expressed protein like GFP, cause morphological phenotypes, mis-regulation of non-targeted genes and activation of the p53 pathway. These effects are highly reproducible, appear to be independent of the targeting sequence and are particularly severe at primitive streak and early somite stages. By contrast, morpholinos do not cause these effects. We propose that pRFPRNAi should only be used with considerable caution and that morpholinos are a preferable approach for gene knock-down during early chick development.
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Affiliation(s)
- Michael Mende
- Department of Craniofacial Development, King's College London, Guy's Campus, Guy's Tower Floor 27, London SE1 9RT, UK
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Becker DL, Webb KF, Thrasivoulou C, Lin CC, Nadershahi R, Tsakiri N, Cook JE. Multiphoton imaging of chick retinal development in relation to gap junctional communication. J Physiol 2007; 585:711-9. [PMID: 17932156 DOI: 10.1113/jphysiol.2007.138776] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Neural progenitor cells in the developing retina extend processes that stretch from the basal vitread surface to the apical ventricular surface. During the cell cycle, the nucleus undergoes interkinetic nuclear migration (INM), moving in a vitread direction during G1, passing through S-phase at its peak and then, on entering G2, returning towards the ventricular surface where it enters M-phase and divides. We have previously shown that individual saltatory movements of the nucleus correlate with transient changes in cytosolic calcium concentration within these progenitor cells and that these events spread to neighbouring progenitors through connexin43 (Cx43) gap junction channels, thereby coordinating the migration of coupled clusters of cells. Disrupting coupling with pharmacological agents, Cx43-specific antisense oligodeoxynucleotides (asODNs) or dominant negative Cx43 (dnCx43) inhibits the sharing of calcium events, reducing the number that each cell experiences and significantly slowing INM. We have developed protocols for imaging migrating progenitor cells by confocal microscopy over relatively short periods, and by multiphoton microscopy over more extended periods that include complete cell cycles. We find that perturbing gap junctional communication not only slows the INM of progenitor cells but also apparently prevents them from changing direction at critical phases of the cell cycle. It also disrupts the migration of young neurons to their appropriate layers after terminal division and leads to their ectopic differentiation. The ability to perform extended time-lapse imaging over 3D volumes in living retina using multiphoton microscopy should now allow fundamental mechanisms governing development of the retinal neuroepithelium to be probed in detail.
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Affiliation(s)
- David L Becker
- Department of Anatomy and Developmental Biology, University College London, Gower Street, London, UK.
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Gorbe A, Krenacs T, Cook JE, Becker DL. Myoblast proliferation and syncytial fusion both depend on connexin43 function in transfected skeletal muscle primary cultures. Exp Cell Res 2007; 313:1135-48. [PMID: 17331498 DOI: 10.1016/j.yexcr.2007.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Revised: 11/03/2006] [Accepted: 01/04/2007] [Indexed: 12/12/2022]
Abstract
Muscles are formed by fusion of individual postmitotic myoblasts to form multinucleated syncytial myotubes. The process requires a well-coordinated transition from proliferation, through migratory alignment and cycle exit, to breakdown of apposed membranes. Connexin43 protein and cell-cycle inhibitor levels are correlated, and gap junction blockers can delay muscle regeneration, so a coordinating role for gap junctions has been proposed. Here, wild-type and dominant-negative connexin43 variants (wtCx43, dnCx43) were introduced into rat myoblasts in primary culture through pIRES-eGFP constructs that made transfected cells fluoresce. GFP-positive cells and vitally-stained nuclei were counted on successive days to reveal differences in proliferation, and myotubes were counted to reveal differences in fusion. Individual transfected cells were injected with Cascade Blue, which permeates gap junctions, mixed with FITC-dextran, which requires cytoplasmic continuity to enter neighbouring cells. Myoblasts transfected with wtCx43 showed more gap-junctional coupling than GFP-only controls, began fusion sooner as judged by the incidence of cytoplasmic coupling, and formed more myotubes. Myoblasts transfected with dnCx43 remained proliferative for longer than either GFP-only or wtCx43 myoblasts, showed less coupling, and underwent little fusion into myotubes. These results highlight the critical role of gap-junctional coupling in myotube formation.
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Affiliation(s)
- Aniko Gorbe
- Department of Biochemistry, Faculty of Medicine, University of Szeged, Szeged, Hungary
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Pearson RA, Lüneborg NL, Becker DL, Mobbs P. Gap junctions modulate interkinetic nuclear movement in retinal progenitor cells. J Neurosci 2006; 25:10803-14. [PMID: 16291954 PMCID: PMC6725838 DOI: 10.1523/jneurosci.2312-05.2005] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
During early retinal development, progenitor cells must divide repeatedly to expand the progenitor pool. During G(1) and G(2) of the cell cycle, progenitor cell nuclei migrate back-and-forth across the proliferative zone in a process termed interkinetic nuclear movement. Because division can only occur at the ventricular surface, factors that affect the speed of nuclear movement could modulate the duration of the cell cycle. Gap-junctional coupling and gap junction-dependent Ca(2+) activity are common features of proliferating cells in the immature nervous system. Furthermore, both gap-junctional coupling and changes in [Ca(2+)](i) have been shown to be positively correlated with the migration of a number of immature cell types. Using time-lapse confocal microscopy, we describe the nature and rate of progenitor cell interkinetic nuclear movement. We show that nuclear movement is usually, but not always, associated with Ca(2+) transients and that buffering of these transients with BAPTA slows movement. Furthermore, we show for the first time that gap-junctional communication is an important requirement for the maintenance of normal nuclear movement in retinal progenitor cells. Conventional blockers of gap junctions and transfection of cells with dominant-negative constructs of connexin 43 (Cx43) and Cx43-specific antisense oligodeoxynucleotides (asODNs) all act to slow interkinetic nuclear movement. The gap junction mimetic peptide Gap26 also acts to slow movement, an effect that we show may be attributable to the blockade of gap junction hemichannels.
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Affiliation(s)
- Rachael A Pearson
- Department of Physiology, University College London, London WC1E 6BT, United Kingdom.
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