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Stevens-Sostre WA, Flores-Aldama L, Bustos D, Li J, Morais-Cabral JH, Delemotte L, Robertson GA. An intracellular hydrophobic nexus critical for hERG1 channel slow deactivation. Biophys J 2024:S0006-3495(24)00026-2. [PMID: 38219015 DOI: 10.1016/j.bpj.2024.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/17/2023] [Accepted: 01/09/2024] [Indexed: 01/15/2024] Open
Abstract
Slow deactivation is a critical property of voltage-gated K+ channels encoded by the human Ether-à-go-go-Related Gene 1 (hERG). hERG1 channel deactivation is modulated by interactions between intracellular N-terminal Per-Arnt-Sim (PAS) and C-terminal cyclic nucleotide-binding homology (CNBh) domains. The PAS domain is multipartite, comprising a globular domain (gPAS; residues 26-135) and an N-terminal PAS-cap that is further subdivided into an initial unstructured "tip" (residues 1-12) and an amphipathic α-helical region (residues 13-25). Although the PAS-cap tip has long been considered the effector of slow deactivation, how its position near the gating machinery is controlled has not been elucidated. Here, we show that a triad of hydrophobic interactions among the gPAS, PAS-cap α helix, and the CNBh domains is required to support slow deactivation in hERG1. The primary sequence of this "hydrophobic nexus" is highly conserved among mammalian ERG channels but shows key differences to fast-deactivating Ether-à-go-go 1 (EAG1) channels. Combining sequence analysis, structure-directed mutagenesis, electrophysiology, and molecular dynamics simulations, we demonstrate that polar serine substitutions uncover an intermediate deactivation mode that is also mimicked by deletion of the PAS-cap α helix. Molecular dynamics simulation analyses of the serine-substituted channels show an increase in distance among the residues of the hydrophobic nexus, a rotation of the intracellular gating ring, and a retraction of the PAS-cap tip from its receptor site near the voltage sensor domain and channel gate. These findings provide compelling evidence that the hydrophobic nexus coordinates the respective components of the intracellular gating ring and positions the PAS-cap tip to control hERG1 deactivation gating.
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Affiliation(s)
- Whitney A Stevens-Sostre
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Lisandra Flores-Aldama
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - Daniel Bustos
- Centro de Investigación de Estudios Avanzados Del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica Del Maule, Talca, Chile; Laboratorio de Bioinformática y Química Computacional (LBQC), Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica Del Maule, Talca, Chile
| | - Jin Li
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - João H Morais-Cabral
- Instituto de Investigação e Inovação Em Saude da Universidade Do Porto (i3S); Instituto de Biologia Molecular e Celular, Universidade Do Porto, Porto, Portugal
| | - Lucie Delemotte
- KTH Royal Institute of Technology, Science for Life Laboratory, Stockholm, Sweden
| | - Gail A Robertson
- Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin.
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2
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Maliszewska-Olejniczak K, Bednarczyk P. Novel insights into the role of ion channels in cellular DNA damage response. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2024; 793:108488. [PMID: 38266668 DOI: 10.1016/j.mrrev.2024.108488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 01/26/2024]
Abstract
The DNA damage response (DDR) is a complex and highly regulated cellular process that detects and repairs DNA damage. The integrity of the DNA molecule is crucial for the proper functioning and survival of cells, as DNA damage can lead to mutations, genomic instability, and various diseases, including cancer. The DDR safeguards the genome by coordinating a series of signaling events and repair mechanisms to maintain genomic stability and prevent the propagation of damaged DNA to daughter cells. The study of an ion channels in the context of DDR is a promising avenue in biomedical research. Lately, it has been reported that the movement of ions through channels plays a crucial role in various physiological processes, including nerve signaling, muscle contraction, cell signaling, and maintaining cell membrane potential. Knowledge regarding the involvement of ion channels in the DDR could support refinement of our approach to several pathologies, mainly cancer, and perhaps lead to innovative therapies. In this review, we focused on the ion channel's possible role in the DDR. We present an analysis of the involvement of ion channels in DDR, their role in DNA repair mechanisms, and cellular outcomes. By addressing these areas, we aim to provide a comprehensive perspective on ion channels in the DDR and potentially guide future research in this field. It is worth noting that the interplay between ion channels and the cellular DDR is complex and multifaceted. More research is needed to fully understand the underlying mechanisms and potential therapeutic implications of these interactions.
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Affiliation(s)
- Kamila Maliszewska-Olejniczak
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland.
| | - Piotr Bednarczyk
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences - SGGW, Warsaw, Poland
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3
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Becchetti A. Interplay of Ca 2+ and K + signals in cell physiology and cancer. CURRENT TOPICS IN MEMBRANES 2023; 92:15-46. [PMID: 38007266 DOI: 10.1016/bs.ctm.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2023]
Abstract
The cytoplasmic Ca2+ concentration and the activity of K+ channels on the plasma membrane regulate cellular processes ranging from mitosis to oriented migration. The interplay between Ca2+ and K+ signals is intricate, and different cell types rely on peculiar cellular mechanisms. Derangement of these mechanisms accompanies the neoplastic progression. The calcium signals modulated by voltage-gated (KV) and calcium-dependent (KCa) K+ channel activity regulate progression of the cell division cycle, the release of growth factors, apoptosis, cell motility and migration. Moreover, KV channels regulate the cell response to the local microenvironment by assembling with cell adhesion and growth factor receptors. This chapter summarizes the pathophysiological roles of Ca2+ and K+ fluxes in normal and cancer cells, by concentrating on several biological systems in which these functions have been studied in depth, such as early embryos, mammalian cell lines, T lymphocytes, gliomas and colorectal cancer cells. A full understanding of the underlying mechanisms will offer a comprehensive view of the ion channel implication in cancer biology and suggest potential pharmacological targets for novel therapeutic approaches in oncology.
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Affiliation(s)
- Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy.
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4
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Sala C, Staderini M, Lottini T, Duranti C, Angelini G, Constantin G, Arcangeli A. Expression of the ether-a-gò-gò-related gene 1 channel during B and T lymphocyte development: role in BCR and TCR signaling. Front Immunol 2023; 14:1111471. [PMID: 37744334 PMCID: PMC10515723 DOI: 10.3389/fimmu.2023.1111471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 08/07/2023] [Indexed: 09/26/2023] Open
Abstract
The functional relevance of K+ and Ca2+ ion channels in the "Store Operated Calcium Entry" (SOCE) during B and T lymphocyte activation is well proven. However, their role in the process of T- and B- cell development and selection is still poorly defined. In this scenario, our aim was to characterize the expression of the ether à-go-go-related gene 1 (ERG1) and KV1.3 K+ channels during the early stages of mouse lymphopoiesis and analyze how they affect Ca2+signaling, or other signaling pathways, known to mediate selection and differentiation processes of lymphoid clones. We provide here evidence that the mouse (m)ERG1 is expressed in primary lymphoid organs, bone marrow (BM), and thymus of C57BL/6 and SV129 mice. This expression is particularly evident in the BM during the developmental stages of B cells, before the positive selection (large and small PreB). mERG1 is also expressed in all thymic subsets of both strains, when lymphocyte positive and negative selection occurs. Partially overlapping results were obtained for KV1.3 expression. mERG1 and KV1.3 were expressed at significantly higher levels in B-cell precursors of mice developing an experimental autoimmune encephalomyelitis (EAE). The pharmacological blockage of ERG1 channels with E4031 produced a significant reduction in intracellular Ca2+ after lymphocyte stimulation in the CD4+ and double-positive T-cell precursors' subsets. This suggests that ERG1 might contribute to maintaining the electrochemical gradient responsible for driving Ca2+ entry, during T-cell receptor signaling which sustains lymphocyte selection checkpoints. Such role mirrors that performed by the shaker-type KV1.3 potassium channel during the activation process of mature lymphocytes. No effects on Ca2+ signaling were observed either in B-cell precursors after blocking KV1.3 with PSORA-4. In the BM, the pharmacological blockage of ERG1 channels produced an increase in ERK phosphorylation, suggesting an effect of ERG1 in regulating B-lymphocyte precursor clones' proliferation and checkpoint escape. Overall, our results suggest a novel physiological function of ERG1 in the processes of differentiation and selection of lymphoid precursors, paving the way to further studies aimed at defining the expression and role of ERG1 channels in immune-based pathologies in addition to that during lymphocyte neoplastic transformation.
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Affiliation(s)
- Cesare Sala
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Martina Staderini
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Tiziano Lottini
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Claudia Duranti
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Gabriele Angelini
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Gabriela Constantin
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
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5
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Lottini T, Duranti C, Iorio J, Martinelli M, Colasurdo R, D’Alessandro FN, Buonamici M, Coppola S, Devescovi V, La Vaccara V, Coppola A, Coppola R, Lastraioli E, Arcangeli A. Combination Therapy with a Bispecific Antibody Targeting the hERG1/β1 Integrin Complex and Gemcitabine in Pancreatic Ductal Adenocarcinoma. Cancers (Basel) 2023; 15:cancers15072013. [PMID: 37046674 PMCID: PMC10093586 DOI: 10.3390/cancers15072013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/10/2023] [Accepted: 03/26/2023] [Indexed: 03/30/2023] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) represents an unmet medical need. Difficult/late diagnosis as well as the poor efficacy and high toxicity of chemotherapeutic drugs result in dismal prognosis. With the aim of improving the treatment outcome of PDAC, we tested the effect of combining Gemcitabine with a novel single chain bispecific antibody (scDb) targeting the cancer-specific hERG1/β1 integrin complex. First, using the scDb (scDb-hERG1-β1) in immunohistochemistry (IHC), Western blot (WB) analysis and immunofluorescence (IF), we confirmed the presence of the hERG1/β1 integrin complex in primary PDAC samples and PDAC cell lines. Combining Gemcitabine with scDb-hERG1-β1 improved its cytotoxicity on all PDAC cells tested in vitro. We also tested the combination treatment in vivo, using an orthotopic xenograft mouse model involving ultrasound-guided injection of PDAC cells. We first demonstrated good penetration of the scDb-hERG1-β1 conjugated with indocyanine green (ICG) into tumour masses by photoacoustic (PA) imaging. Next, we tested the effects of the combination at either therapeutic or sub-optimal doses of Gemcitabine (25 or 5 mg/kg, respectively). The combination of scDb-hERG1-β1 and sub-optimal doses of Gemcitabine reduced the tumour masses to the same extent as the therapeutic doses of Gemcitabine administrated alone; yielded increased survival; and was accompanied by minimised side effects (toxicity). These data pave the way for a novel therapeutic approach to PDAC, based on the combination of low doses of a chemotherapeutic drug (to minimize adverse side effects and the onset of resistance) and the novel scDb-hERG1-β1 targeting the hERG1/β1 integrin complex as neoantigen.
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6
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Chen CY, Wu PY, Van Scoyk M, Simko SA, Chou CF, Winn RA. KCNF1 promotes lung cancer by modulating ITGB4 expression. Cancer Gene Ther 2023; 30:414-423. [PMID: 36385523 PMCID: PMC10014577 DOI: 10.1038/s41417-022-00560-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 10/20/2022] [Accepted: 11/01/2022] [Indexed: 11/17/2022]
Abstract
Lung cancer continues to be the leading cause of cancer death in the United States. Despite recent advances, the five-year survival rate for lung cancer compared to other cancers still remains fairly low. The discovery of molecular targets for lung cancer is key to the development of new approaches and therapies. Electrically silent voltage-gated potassium channel (KvS) subfamilies, which are unable to form functional homotetramers, are implicated in cell-cycle progression, cell proliferation and tumorigenesis. Here, we analyzed the expression of KvS subfamilies in human lung tumors and identified that potassium voltage-gated channel subfamily F member 1 (KCNF1) was up-regulated in non-small cell lung cancer (NSCLC). Silencing of KCNF1 in NSCLC cell lines reduced cell proliferation and tumor progression in mouse xenografts, re-established the integrity of the basement membrane, and enhanced cisplatin sensitivity. KCNF1 was predominately localized in the nucleoplasm and likely mediated its functions in an ion-independent manner. We identified integrin β4 subunit (ITGB4) as a downstream target for KCNF1. Our findings suggest that KCNF1 promotes lung cancer by enhancing ITGB4 signaling and implicate KCNF1 as a novel therapeutic target for lung cancer.
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Affiliation(s)
- Ching-Yi Chen
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Pei-Ying Wu
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Michelle Van Scoyk
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Stephanie A Simko
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Chu-Fang Chou
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Robert A Winn
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA.
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7
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Ukachukwu CU, Jimenez-Vazquez EN, Jain A, Jones DK. hERG1 channel subunit composition mediates proton inhibition of rapid delayed rectifier potassium current (I Kr) in cardiomyocytes derived from hiPSCs. J Biol Chem 2022; 299:102778. [PMID: 36496073 PMCID: PMC9867984 DOI: 10.1016/j.jbc.2022.102778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 11/29/2022] [Accepted: 12/04/2022] [Indexed: 12/13/2022] Open
Abstract
The voltage-gated channel, hERG1, conducts the rapid delayed rectifier potassium current (IKr) and is critical for human cardiac repolarization. Reduced IKr causes long QT syndrome and increases the risk for cardiac arrhythmia and sudden death. At least two subunits form functional hERG1 channels, hERG1a and hERG1b. Changes in hERG1a/1b abundance modulate IKr kinetics, magnitude, and drug sensitivity. Studies from native cardiac tissue suggest that hERG1 subunit abundance is dynamically regulated, but the impact of altered subunit abundance on IKr and its response to external stressors is not well understood. Here, we used a substrate-driven human-induced pluripotent stem cell-derived cardiomyocyte (hiPSC-CM) maturation model to investigate how changes in relative hERG1a/1b subunit abundance impact the response of native IKr to extracellular acidosis, a known component of ischemic heart disease and sudden infant death syndrome. IKr recorded from immatured hiPSC-CMs displays a 2-fold greater inhibition by extracellular acidosis (pH 6.3) compared with matured hiPSC-CMs. Quantitative RT-PCR and immunocytochemistry demonstrated that hERG1a subunit mRNA and protein were upregulated and hERG1b subunit mRNA and protein were downregulated in matured hiPSC-CMs compared with immatured hiPSC-CMs. The shift in subunit abundance in matured hiPSC-CMs was accompanied by increased IKr. Silencing hERG1b's impact on native IKr kinetics by overexpressing a polypeptide identical to the hERG1a N-terminal Per-Arnt-Sim domain reduced the magnitude of IKr proton inhibition in immatured hiPSC-CMs to levels comparable to those observed in matured hiPSC-CMs. These data demonstrate that hERG1 subunit abundance is dynamically regulated and determines IKr proton sensitivity in hiPSC-CMs.
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Affiliation(s)
- Chiamaka U. Ukachukwu
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | | | - Abhilasha Jain
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - David K. Jones
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan, USA,Department of Internal Medicine, University of Michigan Medical School,For correspondence: David K. Jones
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8
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Okafor SN, Angsantikul P, Ahmed H. Discovery of Novel HIV Protease Inhibitors Using Modern Computational Techniques. Int J Mol Sci 2022; 23:12149. [PMID: 36293006 PMCID: PMC9603388 DOI: 10.3390/ijms232012149] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/13/2022] [Accepted: 10/01/2022] [Indexed: 09/10/2023] Open
Abstract
The human immunodeficiency virus type 1 (HIV-1) has continued to be a global concern. With the new HIV incidence, the emergence of multi-drug resistance and the untoward side effects of currently used anti-HIV drugs, there is an urgent need to discover more efficient anti-HIV drugs. Modern computational tools have played vital roles in facilitating the drug discovery process. This research focuses on a pharmacophore-based similarity search to screen 111,566,735 unique compounds in the PubChem database to discover novel HIV-1 protease inhibitors (PIs). We used an in silico approach involving a 3D-similarity search, physicochemical and ADMET evaluations, HIV protease-inhibitor prediction (IC50/percent inhibition), rigid receptor-molecular docking studies, binding free energy calculations and molecular dynamics (MD) simulations. The 10 FDA-approved HIV PIs (saquinavir, lopinavir, ritonavir, amprenavir, fosamprenavir, atazanavir, nelfinavir, darunavir, tipranavir and indinavir) were used as reference. The in silico analysis revealed that fourteen out of the twenty-eight selected optimized hit molecules were within the acceptable range of all the parameters investigated. The hit molecules demonstrated significant binding affinity to the HIV protease (PR) when compared to the reference drugs. The important amino acid residues involved in hydrogen bonding and п-п stacked interactions include ASP25, GLY27, ASP29, ASP30 and ILE50. These interactions help to stabilize the optimized hit molecules in the active binding site of the HIV-1 PR (PDB ID: 2Q5K). HPS/002 and HPS/004 have been found to be most promising in terms of IC50/percent inhibition (90.15%) of HIV-1 PR, in addition to their drug metabolism and safety profile. These hit candidates should be investigated further as possible HIV-1 PIs with improved efficacy and low toxicity through in vitro experiments and clinical trial investigations.
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Affiliation(s)
- Sunday N. Okafor
- Center for Biomedical Research, Population Council, New York, NY 10065, USA
- Department of Pharmaceutical and Medicinal Chemistry, University of Nigeria, Nsukka 41001, Nigeria
| | | | - Hashim Ahmed
- Center for Biomedical Research, Population Council, New York, NY 10065, USA
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9
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Iorio J, Antonuzzo L, Scarpi E, D’Amico M, Duranti C, Messerini L, Sparano C, Caputo D, Lavacchi D, Borzomati D, Antonelli A, Nibid L, Perrone G, Coppola A, Coppola R, di Costanzo F, Lastraioli E, Arcangeli A. Prognostic role of hERG1 Potassium Channels in Neuroendocrine Tumours of the Ileum and Pancreas. Int J Mol Sci 2022; 23:ijms231810623. [PMID: 36142530 PMCID: PMC9504580 DOI: 10.3390/ijms231810623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 11/16/2022] Open
Abstract
hERG1 potassium channels are widely expressed in human cancers of different origins, where they affect several key aspects of cellular behaviour. The present study was designed to evaluate the expression and clinical relevance of hERG1 protein in cancer tissues from patients suffering from neuroendocrine tumours (NETs) of ileal (iNETs) and pancreatic (pNETs) origin, with available clinicopathological history and follow-up. The study was carried out by immunohistochemistry with an anti-hERG1 monoclonal antibody. In a subset of samples, a different antibody directed against the hERG1/β1 integrin complex was also used. The analysis showed for the first time that hERG1 is expressed in human NETs originating from either the ileum or the pancreas. hERG1 turned out to have a prognostic value in NETs, showing (i) a statistically significant positive impact on OS of patients affected by ileal NETs, regardless the TNM stage; (ii) a statistically significant positive impact on OS of patients affected by aggressive (TNM stage IV) disease, either ileal or pancreatic; (iii) a trend to a negative impact on OS of patients affected by less aggressive (TNM stage I-III) disease, either ileal or pancreatic. Moreover, in order to evaluate whether ERG1 was functionally expressed in a cellular model of pNET, the INS1E rat insulinoma cell line was used, and it emerged that blocking ERG1 with a specific inhibitor of the channel (E4031) turned out in a significant reduction in cell proliferation.
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Affiliation(s)
- Jessica Iorio
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Lorenzo Antonuzzo
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Medical Oncology, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy
| | - Emanuela Scarpi
- Unit of Biostatistics and Clinical Trials, IRCCS Istituto Romagnolo per lo Studio dei tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy
| | | | - Claudia Duranti
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Luca Messerini
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Clotilde Sparano
- Endocrinology Unit, Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50134 Florence, Italy
| | - Damiano Caputo
- General Surgery, Campus Bio-Medico University, 00128 Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | - Daniele Lavacchi
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Medical Oncology, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy
| | - Domenico Borzomati
- General Surgery, Campus Bio-Medico University, 00128 Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | - Alice Antonelli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Medical Oncology, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy
| | - Lorenzo Nibid
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
- Pathology Unit, Campus Bio-Medico University, 00128 Rome, Italy
| | - Giuseppe Perrone
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
- Pathology Unit, Campus Bio-Medico University, 00128 Rome, Italy
| | - Alessandro Coppola
- General Surgery, Campus Bio-Medico University, 00128 Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | - Roberto Coppola
- General Surgery, Campus Bio-Medico University, 00128 Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | | | - Elena Lastraioli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Complex Dynamics Study Centre (CSDC), University of Florence, 50100 Florence, Italy
- Correspondence: ; Tel.: +39-(0)5-5275-1319
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Complex Dynamics Study Centre (CSDC), University of Florence, 50100 Florence, Italy
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10
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The Effectiveness of Isoplumbagin and Plumbagin in Regulating Amplitude, Gating Kinetics, and Voltage-Dependent Hysteresis of erg-mediated K+ Currents. Biomedicines 2022; 10:biomedicines10040780. [PMID: 35453530 PMCID: PMC9029050 DOI: 10.3390/biomedicines10040780] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/22/2022] [Accepted: 03/25/2022] [Indexed: 02/04/2023] Open
Abstract
Isoplumbagin (isoPLB, 5-hydroxy-3-methyl-1,4-naphthoquinone), a naturally occurring quinone, has been observed to exercise anti-inflammatory, antimicrobial, and antineoplastic activities. Notably, whether and how isoPLB, plumbagin (PLB), or other related compounds impact transmembrane ionic currents is not entirely clear. In this study, during GH3-cell exposure to isoPLB, the peak and sustained components of an erg (ether-à-go-go related gene)-mediated K+ current (IK(erg)) evoked with long-lasting-step hyperpolarization were concentration-dependently decreased, with a concomitant increase in the decaying time constant of the deactivating current. The presence of isoPLB led to a differential reduction in the peak and sustained components of deactivating IK(erg) with effective IC50 values of 18.3 and 2.4 μM, respectively, while the KD value according to the minimum binding scheme was estimated to be 2.58 μM. Inhibition by isoPLB of IK(erg) was not reversed by diazoxide; however, further addition of isoPLB, during the continued exposure to 4,4′-dithiopyridine, did not suppress IK(erg) further. The recovery of IK(erg) by a two-step voltage pulse with a geometric progression was slowed in the presence of isoPLB, and the decaying rate of IK(erg) activated by the envelope-of-tail method was increased in its presence. The strength of the IK(erg) hysteresis in response to an inverted isosceles-triangular ramp pulse was diminished by adding isoPLB. A mild inhibition of the delayed-rectifier K+ current (IK(DR)) produced by the presence of isoPLB was seen in GH3 cells, while minimal changes in the magnitude of the voltage-gated Na+ current were demonstrated in its presence. Moreover, the IK(erg) identified in MA-10 Leydig tumor cells was blocked by adding isoPLB. Therefore, the effects of isoPLB or PLB on ionic currents (e.g., IK(erg) and IK(DR)) demonstrated herein would be upstream of our previously reported perturbations on mitochondrial morphogenesis or respiration. Taken together, the perturbations of ionic currents by isoPLB or PLB demonstrated herein are likely to contribute to the underlying mechanism through which they, or other structurally similar compounds, result in adjustments in the functional activities of different neoplastic cells (e.g., GH3 and MA-10 cells), presuming that similar in vivo observations occur.
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11
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Fnu G, Weber GF. Alterations of Ion Homeostasis in Cancer Metastasis: Implications for Treatment. Front Oncol 2022; 11:765329. [PMID: 34988012 PMCID: PMC8721045 DOI: 10.3389/fonc.2021.765329] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 11/23/2021] [Indexed: 12/20/2022] Open
Abstract
We have previously reported that metastases from all malignancies are characterized by a core program of gene expression that suppresses extracellular matrix interactions, induces vascularization/tissue remodeling, activates the oxidative metabolism, and alters ion homeostasis. Among these features, the least elucidated component is ion homeostasis. Here we review the literature with the goal to infer a better mechanistic understanding of the progression-associated ionic alterations and identify the most promising drugs for treatment. Cancer metastasis is accompanied by skewing in calcium, zinc, copper, potassium, sodium and chloride homeostasis. Membrane potential changes and water uptake through Aquaporins may also play roles. Drug candidates to reverse these alterations are at various stages of testing, with some having entered clinical trials. Challenges to their utilization comprise differences among tumor types and the involvement of multiple ions in each case. Further, adverse effects may become a concern, as channel blockers, chelators, or supplemented ions will affect healthy and transformed cells alike.
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Affiliation(s)
- Gulimirerouzi Fnu
- College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH, United States
| | - Georg F Weber
- College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, OH, United States
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12
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Conformation-sensitive antibody reveals an altered cytosolic PAS/CNBh assembly during hERG channel gating. Proc Natl Acad Sci U S A 2021; 118:2108796118. [PMID: 34716268 DOI: 10.1073/pnas.2108796118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 09/22/2021] [Indexed: 11/18/2022] Open
Abstract
The human ERG (hERG) K+ channel has a crucial function in cardiac repolarization, and mutations or channel block can give rise to long QT syndrome and catastrophic ventricular arrhythmias. The cytosolic assembly formed by the Per-Arnt-Sim (PAS) and cyclic nucleotide binding homology (CNBh) domains is the defining structural feature of hERG and related KCNH channels. However, the molecular role of these two domains in channel gating remains unclear. We have previously shown that single-chain variable fragment (scFv) antibodies can modulate hERG function by binding to the PAS domain. Here, we mapped the scFv2.12 epitope to a site overlapping with the PAS/CNBh domain interface using NMR spectroscopy and mutagenesis and show that scFv binding in vitro and in the cell is incompatible with the PAS interaction with CNBh. By generating a fluorescently labeled scFv2.12, we demonstrate that association with the full-length hERG channel is state dependent. We detect Förster resonance energy transfer (FRET) with scFv2.12 when the channel gate is open but not when it is closed. In addition, state dependence of scFv2.12 FRET signal disappears when the R56Q mutation, known to destabilize the PAS-CNBh interaction, is introduced in the channel. Altogether, these data are consistent with an extensive structural alteration of the PAS/CNBh assembly when the cytosolic gate opens, likely favoring PAS domain dissociation from the CNBh domain.
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13
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Potassium and Chloride Ion Channels in Cancer: A Novel Paradigm for Cancer Therapeutics. Rev Physiol Biochem Pharmacol 2021; 183:135-155. [PMID: 34291318 DOI: 10.1007/112_2021_62] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Cancer is a collection of diseases caused by specific changes at the genomic level that support cell proliferation indefinitely. Traditionally, ion channels are known to control a variety of cellular processes including electrical signal generation and transmission, secretion, and contraction by controlling ionic gradients. However, recent studies had brought to light important facts on ion channels in cancer biology.In this review we discuss the mechanism linking potassium or chloride ion channel activity to biochemical pathways controlling proliferation in cancer cells and the potential advantages of targeting ion channels as an anticancer therapeutic option.
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14
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Ríos-Pérez EB, Liu F, Stevens-Sostre WA, Eichel CA, Silignavong J, Robertson GA. A stable cell line inducibly expressing hERG1a/1b heteromeric channels. J Pharmacol Toxicol Methods 2021; 110:107081. [PMID: 34058320 DOI: 10.1016/j.vascn.2021.107081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 04/07/2021] [Accepted: 05/20/2021] [Indexed: 11/24/2022]
Abstract
Heterologously expressed hERG channels represent a mainstay of in vitro drug safety screens intended to mitigate risk of cardiac IKr block and sudden cardiac death. This is true even as more channel types are adopted as part of the Comprehensive in vitro Proarrhythmia Assay (CiPA) intended to elevate specificity and thus enhance throughput of promising lead drugs. Until now, hERG1a homomeric channels have been used as a proxy for IKr despite a wealth of evidence showing that hERG1a/1b heteromers better represent native channels in terms of protein abundance and channel biophysical and pharmacological properties. Past efforts to create a stable hERG1a/1b cell line were met with unpredictable silencing of hERG1b expression despite stable integration of the gene into the HEK293 cell genome. Here we report a new cell line stably expressing hERG1a, with hERG1b reliably controlled by an inducible promoter sensitive to doxycycline. Co-immunoprecipitation, Western blot analysis and patch-clamp electrophysiology confirm the heteromeric composition of the expressed channels. Association with hERG1b was found to promote hERG1a protein levels and enhance membrane current levels. Optimal conditions for drug screening and experimental investigation were achieved at 24 h exposure to 100 ng/ml doxycycline. Differences in pharmacological sensitivity between homomeric and heteromeric channels were observed for dofetilide and ebastine, but not fluoxetine, as evaluated by their IC50 values. Using these values in the O'Hara-Rudy-CiPA in silico model revealed discrepancies in pro-arrhythmia risk, implying the hERG1a homomeric platform overestimates risk for these two drugs. Dofetilide block was use-dependent and faster for hERG1a/1b than hERG1a channels, whereas ebastine showed considerable block at rest and had a slower progression for hERG1a/1b channels. The hERG1a/1b cell line thus represents an advanced model for contemporary drug safety screening assays such as CiPA that employ IC50 values to estimate risk of proarrhythmia in computational models of ventricular cardiomyocytes. This novel technology fulfills an unmet need to enhance specificity and foster a safe yet expanded drug development pipeline.
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Affiliation(s)
- Erick B Ríos-Pérez
- Dept. of Neuroscience and Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave. #5505, Madison, WI 53705, United States of America
| | - Fang Liu
- Dept. of Neuroscience and Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave. #5505, Madison, WI 53705, United States of America
| | - Whitney A Stevens-Sostre
- Dept. of Neuroscience and Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave. #5505, Madison, WI 53705, United States of America
| | - Catherine A Eichel
- Dept. of Neuroscience and Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave. #5505, Madison, WI 53705, United States of America
| | - Jonathan Silignavong
- Dept. of Neuroscience and Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave. #5505, Madison, WI 53705, United States of America
| | - Gail A Robertson
- Dept. of Neuroscience and Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, 1111 Highland Ave. #5505, Madison, WI 53705, United States of America.
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15
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Feng L, Zhang J, Lee C, Kim G, Liu F, Petersen AJ, Lim E, Anderson CL, Orland KM, Robertson GA, Eckhardt LL, January CT, Kamp TJ. Long QT Syndrome KCNH2 Variant Induces hERG1a/1b Subunit Imbalance in Patient-Specific Induced Pluripotent Stem Cell-Derived Cardiomyocytes. Circ Arrhythm Electrophysiol 2021; 14:e009343. [PMID: 33729832 PMCID: PMC8058932 DOI: 10.1161/circep.120.009343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Li Feng
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
- Department of Cardiology, Beijing Anzhen Hospital, Capital Medical University, National Clinical Research Center for Cardiovascular Diseases, Beijing, China
| | - Jianhua Zhang
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
| | - ChangHwan Lee
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY
| | - Gina Kim
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
| | - Fang Liu
- Department of Neuroscience, Wisconsin Institutes for Medical Research, University of Wisconsin-Madison, Madison, WI
| | | | - Evi Lim
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
| | - Corey L. Anderson
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
| | - Kate M. Orland
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
| | - Gail A. Robertson
- Department of Neuroscience, Wisconsin Institutes for Medical Research, University of Wisconsin-Madison, Madison, WI
| | - Lee L. Eckhardt
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
| | - Craig T. January
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
| | - Timothy J. Kamp
- Cellular and Molecular Arrhythmia Research Program, Department of Medicine, Division of Cardiovascular Medicine, University of Wisconsin-Madison, Madison, WI
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
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16
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Lu C, Ma Z, Cheng X, Wu H, Tuo B, Liu X, Li T. Pathological role of ion channels and transporters in the development and progression of triple-negative breast cancer. Cancer Cell Int 2020; 20:377. [PMID: 32782435 PMCID: PMC7409684 DOI: 10.1186/s12935-020-01464-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 07/26/2020] [Accepted: 07/29/2020] [Indexed: 12/12/2022] Open
Abstract
Breast cancer is a common malignancy in women. Among breast cancer types, triple-negative breast cancer (TNBC) tends to affect younger women, is prone to axillary lymph node, lung, and bone metastases; and has a high recurrence rate. Due to a lack of classic biomarkers, the currently available treatments are surgery and chemotherapy; no targeted standard treatment options are available. Therefore, it is urgent to find a novel and effective therapeutic target. As alteration of ion channels and transporters in normal mammary cells may affect cell growth, resulting in the development and progression of TNBC, ion channels and transporters may be promising new therapeutic targets for TNBC. This review summarizes ion channels and transporters related to TNBC and may provide new tumor biomarkers and help in the development of novel targeted therapies.
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Affiliation(s)
- Chengli Lu
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003 Guizhou Province China
| | - Zhiyuan Ma
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003 Guizhou Province China
| | - Xiaoming Cheng
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003 Guizhou Province China
| | - Huichao Wu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province China.,Digestive Disease Institute of Guizhou Province, Zunyi, Guizhou Province China
| | - Xuemei Liu
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003, Guizhou Province China.,Digestive Disease Institute of Guizhou Province, Zunyi, Guizhou Province China
| | - Taolang Li
- Department of Thyroid and Breast Surgery, Affiliated Hospital of Zunyi Medical University, Zunyi, 563003 Guizhou Province China
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17
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Rosendo-Pineda MJ, Moreno CM, Vaca L. Role of ion channels during cell division. Cell Calcium 2020; 91:102258. [PMID: 32736154 DOI: 10.1016/j.ceca.2020.102258] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/20/2020] [Accepted: 07/20/2020] [Indexed: 02/06/2023]
Abstract
Ion channels are transmembrane proteins whose canonical function is the transport of ions across the plasma membrane to regulate cell membrane potential and play an essential role in neural communication, nerve conduction, and muscle contraction. However, over the last few years, non-canonical functions have been identified for many channels, having active roles in phagocytosis, invasiveness, proliferation, among others. The participation of some channels in cell proliferation has raised the question of whether they may play an active role in mitosis. There are several reports showing the participation of channels during interphase, however, the direct participation of ion channels in mitosis has received less attention. In this article, we summarize the current evidence on the participation of ion channels in mitosis. We also summarize some tools that would allow the study of ion channels and cell cycle regulatory molecules in individual cells during mitosis.
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Affiliation(s)
| | - Claudia M Moreno
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA
| | - Luis Vaca
- Instituto de Fisiología Celular. Universidad Nacional Autónoma de México. Ciudad Universitaria, Coyoacán, DF, 04510, Mexico; Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA, 98195, USA.
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18
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Iorio J, Duranti C, Lottini T, Lastraioli E, Bagni G, Becchetti A, Arcangeli A. K V11.1 Potassium Channel and the Na +/H + Antiporter NHE1 Modulate Adhesion-Dependent Intracellular pH in Colorectal Cancer Cells. Front Pharmacol 2020; 11:848. [PMID: 32587517 PMCID: PMC7297984 DOI: 10.3389/fphar.2020.00848] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/22/2020] [Indexed: 12/16/2022] Open
Abstract
Increasing evidence indicates that ion channels and transporters cooperate in regulating different aspects of tumor pathophysiology. In cancer cells, H+/HCO3- transporters usually invert the transmembrane pH gradient typically observed in non-neoplastic cells, which is thought to contribute to cancer malignancy. To what extent the pH-regulating transporters are functionally linked to K+ channels, which are central regulators of cell membrane potential (Vm), is unclear. We thus investigated in colorectal cancer cells the implication of the pH-regulating transporters and KV11.1 (also known as hERG1) in the pH modifications stimulated by integrin-dependent cell adhesion. Colorectal cancer cell lines (HCT 116 and HT 29) were seeded onto β1 integrin-dependent substrates, collagen I and fibronectin. This led to a transient cytoplasmic alkalinization, which peaked at 90 min of incubation, lasted approximately 180 min, and was inhibited by antibodies blocking the β1 integrin. The effect was sensitive to amiloride (10 µM) and cariporide (5 µM), suggesting that it was mainly caused by the activity of the Na+/H+ antiporter NHE1. Blocking KV11.1 with E4031 shows that channel activity contributed to modulate the β1 integrin-dependent pHi increase. Interestingly, both NHE1 and KV11.1 modulated the colorectal cancer cell motility triggered by β1 integrin-dependent adhesion. Finally, the β1 integrin subunit, KV11.1 and NHE1 co-immunoprecipitated in colorectal cancer cells seeded onto Collagen I, suggesting the formation of a macromolecular complex following integrin-mediated adhesion. We conclude that the interaction between KV11.1, NHE1, and β1 integrin contributes to regulate colorectal cancer intracellular pH in relation to the tumor microenvironment, suggesting novel pharmacological targets to counteract pro-invasive and, hence, pro-metastatic behavior in colorectal cancer.
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Affiliation(s)
- Jessica Iorio
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Claudia Duranti
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Tiziano Lottini
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Elena Lastraioli
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Giacomo Bagni
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano Bicocca, Milano, Italy
| | - Annarosa Arcangeli
- Section of Internal Medicine, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
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19
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Palme D, Misovic M, Ganser K, Klumpp L, Salih HR, Zips D, Huber SM. hERG K + Channels Promote Survival of Irradiated Leukemia Cells. Front Pharmacol 2020; 11:489. [PMID: 32390841 PMCID: PMC7194033 DOI: 10.3389/fphar.2020.00489] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 03/27/2020] [Indexed: 12/19/2022] Open
Abstract
Many tumor cells express highly elevated activities of voltage-gated K+ channels in the plasma membrane which are indispensable for tumor growth. To test for K+ channel function during DNA damage response, we subjected human chronic myeloid leukemia (CML) cells to sub-lethal doses of ionizing radiation (0-8 Gy, 6 MV photons) and determined K+ channel activity, K+ channel-dependent Ca2+ signaling, cell cycle progression, DNA repair, and clonogenic survival by whole-cell patch clamp recording, fura-2 Ca2+ imaging, Western blotting, flow cytometry, immunofluorescence microscopy, and pre-plating colony formation assay, respectively. As a result, the human erythroid CML cell line K562 and primary human CML cells functionally expressed hERG1. Irradiation stimulated in both cell types an increase in the activity of hERG1 K+ channels which became apparent 1-2 h post-irradiation. This increase in K+ channel activity was paralleled by an accumulation in S phase of cell cycle followed by a G2/M cell cycle arrest as analyzed between 8 and 72 h post-irradiation. Attenuating the K+ channel function by applying the hERG1 channel inhibitor E4031 modulated Ca2+ signaling, impaired inhibition of the mitosis promoting subunit cdc2, overrode cell cycle arrest, and decreased clonogenic survival of the irradiated cells but did not affect repair of DNA double strand breaks suggesting a critical role of the hERG1 K+ channels for the Ca2+ signaling and the cell cycle control during DNA damage response.
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Affiliation(s)
- Daniela Palme
- Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany
| | - Milan Misovic
- Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany
| | - Katrin Ganser
- Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany
| | - Lukas Klumpp
- Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany
| | - Helmut R Salih
- Clinical Collaboration Unit Translational Immunology, German Cancer Consortium (DKTK), University Hospital Tübingen, Tübingen, Germany
| | - Daniel Zips
- Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany.,German Cancer Consortium (DKTK), Partner Site Tübingen, Tübingen, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Stephan M Huber
- Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany
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20
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He S, Moutaoufik MT, Islam S, Persad A, Wu A, Aly KA, Fonge H, Babu M, Cayabyab FS. HERG channel and cancer: A mechanistic review of carcinogenic processes and therapeutic potential. Biochim Biophys Acta Rev Cancer 2020; 1873:188355. [PMID: 32135169 DOI: 10.1016/j.bbcan.2020.188355] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 02/28/2020] [Accepted: 02/28/2020] [Indexed: 12/21/2022]
Abstract
The human ether-à-go-go related gene (HERG) encodes the alpha subunit of Kv11.1, which is a voltage-gated K+ channel protein mainly expressed in heart and brain tissue. HERG plays critical role in cardiac repolarization, and mutations in HERG can cause long QT syndrome. More recently, evidence has emerged that HERG channels are aberrantly expressed in many kinds of cancer cells and play important roles in cancer progression. HERG could therefore be a potential biomarker for cancer and a possible molecular target for anticancer drug design. HERG affects a number of cellular processes, including cell proliferation, apoptosis, angiogenesis and migration, any of which could be affected by dysregulation of HERG. This review provides an overview of available information on HERG channel as it relates to cancer, with focus on the mechanism by which HERG influences cancer progression. Molecular docking attempts suggest two possible protein-protein interactions of HERG with the ß1-integrin receptor and the transcription factor STAT-1 as novel HERG-directed therapeutic targeting which avoids possible cardiotoxicity. The role of epigenetics in regulating HERG channel expression and activity in cancer will also be discussed. Finally, given its inherent extracellular accessibility as an ion channel, we discuss regulatory roles of this molecule in cancer physiology and therapeutic potential. Future research should be directed to explore the possibilities of therapeutic interventions targeting HERG channels while minding possible complications.
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Affiliation(s)
- Siyi He
- Department of Surgery, Neuroscience Research Group, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | | | - Saadul Islam
- Department of Surgery, Neuroscience Research Group, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Amit Persad
- Department of Surgery, Neuroscience Research Group, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Adam Wu
- Department of Surgery, Neuroscience Research Group, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Khaled A Aly
- Department of Biochemistry, University of Regina, Regina, SK S4S 0A2, Canada
| | - Humphrey Fonge
- Department of Medical Imaging, University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W8, Canada; Department of Medical Imaging, Royal University Hospital, Saskatoon, Saskatchewan S7N 0W8, Canada
| | - Mohan Babu
- Department of Biochemistry, University of Regina, Regina, SK S4S 0A2, Canada
| | - Francisco S Cayabyab
- Department of Surgery, Neuroscience Research Group, College of Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
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21
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Shults NV, Rybka V, Suzuki YJ, Brelidze TI. Increased Smooth Muscle Kv11.1 Channel Expression in Pulmonary Hypertension and Protective Role of Kv11.1 Channel Blocker Dofetilide. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:48-56. [PMID: 31839145 PMCID: PMC6943378 DOI: 10.1016/j.ajpath.2019.09.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/05/2019] [Accepted: 09/17/2019] [Indexed: 01/08/2023]
Abstract
Kv11.1 potassium channels are essential for heart repolarization. Prescription medication that blocks Kv11.1 channels lengthens the ventricular action potential and causes cardiac arrhythmias. Surprisingly little is known about the Kv11.1 channel expression and function in the lung tissue. Here we report that Kv11.1 channels were abundantly expressed in the large pulmonary arteries (PAs) of healthy lung tissues from humans and rats. Kv11.1 channel expression was increased in the lungs of humans affected by chronic obstructive pulmonary disease-associated pulmonary hypertension and in the lungs of rats with pulmonary arterial hypertension (PAH). In healthy lung tissues from humans and rats, Kv11.1 channels were confined to the large PAs. In humans with chronic obstructive pulmonary disease-associated pulmonary hypertension and in rats with PAH, Kv11.1 channels were expressed in both the large and small PAs. The increase in Kv11.1 channel expression closely followed the time-course of the development of pulmonary vascular remodeling in PAH rats. Treatment of PAH rats with dofetilide, an Kv11.1 channel blocker approved by the US Food and Drug Administration for use in the treatment of arrythmia, inhibited PAH-associated pulmonary vascular remodeling. Taken together, the findings from this study uncovered a novel role of Kv11.1 channels in lung function and their potential as new drug targets in the treatment of pulmonary hypertension. The protective effect of dofetilide raises the possibility of repurposing this antiarrhythmic drug for the treatment of patients with pulmonary hypertension.
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MESH Headings
- Adult
- Aged
- Aged, 80 and over
- Animals
- Arrhythmias, Cardiac/etiology
- Arrhythmias, Cardiac/pathology
- Arrhythmias, Cardiac/prevention & control
- Case-Control Studies
- ERG1 Potassium Channel/antagonists & inhibitors
- ERG1 Potassium Channel/metabolism
- Female
- Follow-Up Studies
- Humans
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Phenethylamines/pharmacology
- Potassium Channel Blockers/pharmacology
- Prognosis
- Pulmonary Arterial Hypertension/complications
- Pulmonary Arterial Hypertension/metabolism
- Pulmonary Arterial Hypertension/pathology
- Rats, Sprague-Dawley
- Sulfonamides/pharmacology
- Vascular Remodeling/drug effects
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Affiliation(s)
- Nataliia V Shults
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, District of Columbia
| | - Vladyslava Rybka
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, District of Columbia
| | - Yuichiro J Suzuki
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, District of Columbia
| | - Tinatin I Brelidze
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, District of Columbia.
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22
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Ion Channel Dysregulation in Head and Neck Cancers: Perspectives for Clinical Application. Rev Physiol Biochem Pharmacol 2020; 181:375-427. [PMID: 32789787 DOI: 10.1007/112_2020_38] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Head and neck cancers are a highly complex and heterogeneous group of malignancies that involve very diverse anatomical structures and distinct aetiological factors, treatments and clinical outcomes. Among them, head and neck squamous cell carcinomas (HNSCC) are predominant and the sixth most common cancer worldwide with still low survival rates. Omic technologies have unravelled the intricacies of tumour biology, harbouring a large diversity of genetic and molecular changes to drive the carcinogenesis process. Nonetheless, this remarkable heterogeneity of molecular alterations opens up an immense opportunity to discover novel biomarkers and develop molecular-targeted therapies. Increasing evidence demonstrates that dysregulation of ion channel expression and/or function is frequently and commonly observed in a variety of cancers from different origin. As a consequence, the concept of ion channels as potential membrane therapeutic targets and/or biomarkers for cancer diagnosis and prognosis has attracted growing attention. This chapter intends to comprehensively and critically review the current state-of-art ion channel dysregulation specifically focusing on head and neck cancers and to formulate the major challenges and research needs to translate this knowledge into clinical application. Based on current reported data, various voltage-gated potassium (Kv) channels (i.e. Kv3.4, Kv10.1 and Kv11.1) have been found frequently aberrantly expressed in HNSCC as well as precancerous lesions and are highlighted as clinically and biologically relevant features in both early stages of tumourigenesis and late stages of disease progression. More importantly, they also emerge as promising candidates as cancer risk markers, tumour markers and potential anti-proliferative and anti-metastatic targets for therapeutic interventions; however, the oncogenic properties seem to be independent of their ion-conducting function.
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Vaddi DR, Piao L, Khan SA, Wang N, Prabhakar NR, Nanduri J. Hypoxia induced hERG trafficking defect linked to cell cycle arrest in SH-SY5Y cells. PLoS One 2019; 14:e0215905. [PMID: 31017964 PMCID: PMC6481834 DOI: 10.1371/journal.pone.0215905] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 04/10/2019] [Indexed: 11/18/2022] Open
Abstract
The alpha subunit of the voltage gated human ether-a-go-go-related (hERG) potassium channel regulates cell excitability in a broad range of cell lines. HERG channels are also expressed in a variety of cancer cells and control cell proliferation and apoptosis. Hypoxia, a common feature of tumors, alters gating properties of hERG currents in SH-SY5Y neuroblastoma cells. In the present study, we examined the molecular mechanisms and physiological significance underlying hypoxia-altered hERG currents in SH-SY5Y neuroblastoma cells. Hypoxia reduced the surface expression of 150kDa form and increased 125kDa form of hERG protein expression in the endoplasmic reticulum (ER). The changes in protein expression were associated with ~50% decrease in hERG potassium conductance. ER retention of hERG 125kDa form by CH was due to defective trafficking and was rescued by exposing cells to hypoxia at low temperatures or treatment with E-4031, a hERG channel blocker. Prolonged association of hERG with molecular chaperone Hsp90 resulting in complex oligomeric insoluble aggregates contributed to ER accumulation and trafficking defect. Hypoxia increased reactive oxygen species (ROS) levels and manganese (111) tetrakis (1methyl-4-pyridyl) porphyrin pentachloride, a membrane-permeable antioxidant prevented hypoxia-induced degradation of 150kDa and accumulation of 125kDa forms. Impaired trafficking of hERG by hypoxia was associated with reduced cell proliferation and this effect was prevented by antioxidant treatment. These results demonstrate that hypoxia through increased oxidative stress impairs hERG trafficking, leading to decreased K+ currents resulting in cell cycle arrest in SH-SY5Y cells.
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Affiliation(s)
- Damodara Reddy Vaddi
- Institute for Integrative Physiology, Center for Systems Biology of O2 Sensing, Biological Sciences Division, The University of Chicago, Chicago, Illinois, United States of America
| | - Lin Piao
- Institute for Integrative Physiology, Center for Systems Biology of O2 Sensing, Biological Sciences Division, The University of Chicago, Chicago, Illinois, United States of America
| | - Shakil A. Khan
- Institute for Integrative Physiology, Center for Systems Biology of O2 Sensing, Biological Sciences Division, The University of Chicago, Chicago, Illinois, United States of America
| | - Ning Wang
- Institute for Integrative Physiology, Center for Systems Biology of O2 Sensing, Biological Sciences Division, The University of Chicago, Chicago, Illinois, United States of America
| | - Nanduri R. Prabhakar
- Institute for Integrative Physiology, Center for Systems Biology of O2 Sensing, Biological Sciences Division, The University of Chicago, Chicago, Illinois, United States of America
| | - Jayasri Nanduri
- Institute for Integrative Physiology, Center for Systems Biology of O2 Sensing, Biological Sciences Division, The University of Chicago, Chicago, Illinois, United States of America
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Cancer-Associated Intermediate Conductance Ca 2+-Activated K⁺ Channel K Ca3.1. Cancers (Basel) 2019; 11:cancers11010109. [PMID: 30658505 PMCID: PMC6357066 DOI: 10.3390/cancers11010109] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/10/2019] [Accepted: 01/13/2019] [Indexed: 12/14/2022] Open
Abstract
Several tumor entities have been reported to overexpress KCa3.1 potassium channels due to epigenetic, transcriptional, or post-translational modifications. By modulating membrane potential, cell volume, or Ca2+ signaling, KCa3.1 has been proposed to exert pivotal oncogenic functions in tumorigenesis, malignant progression, metastasis, and therapy resistance. Moreover, KCa3.1 is expressed by tumor-promoting stroma cells such as fibroblasts and the tumor vasculature suggesting a role of KCa3.1 in the adaptation of the tumor microenvironment. Combined, this features KCa3.1 as a candidate target for innovative anti-cancer therapy. However, immune cells also express KCa3.1 thereby contributing to T cell activation. Thus, any strategy targeting KCa3.1 in anti-cancer therapy may also modulate anti-tumor immune activity and/or immunosuppression. The present review article highlights the potential of KCa3.1 as an anti-tumor target providing an overview of the current knowledge on its function in tumor pathogenesis with emphasis on vasculo- and angiogenesis as well as anti-cancer immune responses.
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Prevarskaya N, Skryma R, Shuba Y. Ion Channels in Cancer: Are Cancer Hallmarks Oncochannelopathies? Physiol Rev 2018; 98:559-621. [PMID: 29412049 DOI: 10.1152/physrev.00044.2016] [Citation(s) in RCA: 272] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Genomic instability is a primary cause and fundamental feature of human cancer. However, all cancer cell genotypes generally translate into several common pathophysiological features, often referred to as cancer hallmarks. Although nowadays the catalog of cancer hallmarks is quite broad, the most common and obvious of them are 1) uncontrolled proliferation, 2) resistance to programmed cell death (apoptosis), 3) tissue invasion and metastasis, and 4) sustained angiogenesis. Among the genes affected by cancer, those encoding ion channels are present. Membrane proteins responsible for signaling within cell and among cells, for coupling of extracellular events with intracellular responses, and for maintaining intracellular ionic homeostasis ion channels contribute to various extents to pathophysiological features of each cancer hallmark. Moreover, tight association of these hallmarks with ion channel dysfunction gives a good reason to classify them as special type of channelopathies, namely oncochannelopathies. Although the relation of cancer hallmarks to ion channel dysfunction differs from classical definition of channelopathies, as disease states causally linked with inherited mutations of ion channel genes that alter channel's biophysical properties, in a broader context of the disease state, to which pathogenesis ion channels essentially contribute, such classification seems absolutely appropriate. In this review the authors provide arguments to substantiate such point of view.
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Affiliation(s)
- Natalia Prevarskaya
- INSERM U-1003, Equipe Labellisée par la Ligue Nationale contre le Cancer et LABEX, Université Lille1 , Villeneuve d'Ascq , France ; Bogomoletz Institute of Physiology and International Center of Molecular Physiology, NASU, Kyiv-24, Ukraine
| | - Roman Skryma
- INSERM U-1003, Equipe Labellisée par la Ligue Nationale contre le Cancer et LABEX, Université Lille1 , Villeneuve d'Ascq , France ; Bogomoletz Institute of Physiology and International Center of Molecular Physiology, NASU, Kyiv-24, Ukraine
| | - Yaroslav Shuba
- INSERM U-1003, Equipe Labellisée par la Ligue Nationale contre le Cancer et LABEX, Université Lille1 , Villeneuve d'Ascq , France ; Bogomoletz Institute of Physiology and International Center of Molecular Physiology, NASU, Kyiv-24, Ukraine
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26
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The Interaction between the Drosophila EAG Potassium Channel and the Protein Kinase CaMKII Involves an Extensive Interface at the Active Site of the Kinase. J Mol Biol 2018; 430:5029-5049. [PMID: 30381148 DOI: 10.1016/j.jmb.2018.10.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 10/23/2018] [Accepted: 10/23/2018] [Indexed: 12/12/2022]
Abstract
The Drosophila EAG (dEAG) potassium channel is the founding member of the superfamily of KNCH channels, which are involved in cardiac repolarization, neuronal excitability and cellular proliferation. In flies, dEAG is involved in regulation of neuron firing and assembles with CaMKII to form a complex implicated in memory formation. We have characterized the interaction between the kinase domain of CaMKII and a 53-residue fragment of the dEAG channel that includes a canonical CaMKII recognition sequence. Crystal structures together with biochemical/biophysical analysis show a substrate-kinase complex with an unusually tight and extensive interface that appears to be strengthened by phosphorylation of the channel fragment. Electrophysiological recordings show that catalytically active CaMKII is required to observe active dEAG channels. A previously identified phosphorylation site in the recognition sequence is not the substrate for this crucial kinase activity, but rather contributes importantly to the tight interaction of the kinase with the channel. The available data suggest that the dEAG channel is a docking platform for the kinase and that phosphorylation of the channel's kinase recognition sequence modulates the strength of the interaction between the channel and the kinase.
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27
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Shah RR, Stonier PD. Repurposing old drugs in oncology: Opportunities with clinical and regulatory challenges ahead. J Clin Pharm Ther 2018; 44:6-22. [PMID: 30218625 DOI: 10.1111/jcpt.12759] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 08/08/2018] [Accepted: 08/19/2018] [Indexed: 12/11/2022]
Abstract
WHAT IS KNOWN AND OBJECTIVE In order to expedite the availability of drugs to treat cancers in a cost-effective manner, repurposing of old drugs for oncological indications is gathering momentum. Revolutionary advances in pharmacology and genomics have demonstrated many old drugs to have activity at novel antioncogenic pharmacological targets. We decided to investigate whether prospective studies support the promises of nonclinical and retrospective clinical studies on repurposing three old drugs, namely metformin, valproate and astemizole. METHODS We conducted an extensive literature search through PubMed to gather representative nonclinical and retrospective clinical studies that investigated the potential repurposing of these three drugs for oncological indications. We then searched for prospective studies aimed at confirming the promises of retrospective data. RESULTS AND DISCUSSION While evidence from nonclinical and retrospective clinical studies with these drugs appears highly promising, large scale prospective studies are either lacking or have failed to substantiate this promise. We provide a brief discussion of some of the challenges in repurposing. Principal challenges and obstacles relate to heterogeneity of cancers studied without considering their molecular signatures, trials with small sample size and short duration, failure consider issues of ethnicity of study population and effective antioncogenic doses of the drug studied. WHAT IS NEW AND CONCLUSION Well-designed prospective studies demonstrating efficacy are required for repurposing old drugs for oncology indications, just as they are for new chemical entities for any indication. Early and ongoing interactions with regulatory authorities are invaluable. We outline a tentative framework for a structured approach to repurposing old drugs for novel indications in oncology.
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Affiliation(s)
- Rashmi R Shah
- Pharmaceutical Consultant, Gerrards Cross, Buckinghamshire, UK
| | - Peter D Stonier
- Department of Pharmaceutical Medicine, School of Cancer and Pharmaceutical Sciences, Faculty of Life Sciences and Medicine, King's College, London, UK
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Flinck M, Kramer SH, Pedersen SF. Roles of pH in control of cell proliferation. Acta Physiol (Oxf) 2018; 223:e13068. [PMID: 29575508 DOI: 10.1111/apha.13068] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 02/17/2018] [Accepted: 03/19/2018] [Indexed: 02/06/2023]
Abstract
Precise spatiotemporal regulation of intracellular pH (pHi ) is a prerequisite for normal cell function, and changes in pHi or pericellular pH (pHe ) exert important signalling functions. It is well established that proliferation of mammalian cells is dependent on a permissive pHi in the slightly alkaline range (7.0-7.2). It is also clear that mitogen signalling in nominal absence of HCO3- is associated with an intracellular alkalinization (~0.3 pH unit above steady-state pHi ), which is secondary to activation of Na+ /H+ exchange. However, it remains controversial whether this increase in pHi is part of the mitogenic signal cascade leading to cell cycle entry and progression, and whether it is relevant under physiological conditions. Furthermore, essentially all studies of pHi in mammalian cell proliferation have focused on the mitogen-induced G0-G1 transition, and the regulation and roles of pHi during the cell cycle remain poorly understood. The aim of this review is to summarize and critically discuss the possible roles of pHi and pHe in cell cycle progression. While the focus is on the mammalian cell cycle, important insights from studies in lower eukaryotes are also discussed. We summarize current evidence of links between cell cycle progression and pHi and discuss possible pHi - and pHe sensors and signalling pathways relevant to mammalian proliferation control. The possibility that changes in pHi during cell cycle progression may be an integral part of the checkpoint control machinery is explored. Finally, we discuss the relevance of links between pH and proliferation in the context of the perturbed pH homoeostasis and acidic microenvironment of solid tumours.
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Affiliation(s)
- M. Flinck
- Section for Cell Biology and Physiology; Department of Biology; Faculty of Science; University of Copenhagen; Copenhagen Denmark
| | - S. H. Kramer
- Section for Cell Biology and Physiology; Department of Biology; Faculty of Science; University of Copenhagen; Copenhagen Denmark
| | - S. F. Pedersen
- Section for Cell Biology and Physiology; Department of Biology; Faculty of Science; University of Copenhagen; Copenhagen Denmark
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29
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Lefranc F, Le Rhun E, Kiss R, Weller M. Glioblastoma quo vadis: Will migration and invasiveness reemerge as therapeutic targets? Cancer Treat Rev 2018; 68:145-154. [PMID: 30032756 DOI: 10.1016/j.ctrv.2018.06.017] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 06/19/2018] [Accepted: 06/21/2018] [Indexed: 12/18/2022]
Abstract
PURPOSE The purpose of the current review is to highlight, on one hand, the fact that the migratory pattern of glioma cells is the major obstacle to combat them with chemotherapy, and on the other one, the new treatment strategies to overcome this obstacle. METHODS This review surveys several membrane and extracellular molecules involved in glioma cell migration, invasiveness and resistance to apoptosis. RESULTS This review focuses on signaling pathways implicated in the positive regulation of glioblastoma cell migration, including glutamate and ion channel networks, microtubes and membrane-derived extracellular vesicles (EV) containing microRNAs. Glioma cells release glutamate to the extracellular matrix, inducing neuronal cell death, which may facilitate glioma growth and invasion. Glioma cell migration and invasion are further facilitated through ion channels and transporters that modify cellular volume. Microtubes and EV promote connections and communication among glioma cells and with the microenvironment and are associated with progression and resistance to therapy. Potential therapies linked to these pathways for glioblastoma are being developed. CONCLUSION Our view is evolving from an intracellular view of the complex intracellular signaling pathways to one of orchestral machinery, including connections between heterogeneous tumoral and nontumoral cells and with the microenvironment through channels, microtubes, and extracellular miRNA, generating different signals at different times. All of these elements give rise to a new perspective for the treatment of glioblastoma.
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Affiliation(s)
- Florence Lefranc
- Department of Neurosurgery, Hôpital Erasme; Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium.
| | - Emilie Le Rhun
- University of Lille, U-1192, F-59000 Lille, France; Inserm, U-1192, F-59000 Lille, France; CHU Lille, General and Stereotaxic Neurosurgery Service, F-59000 Lille, France
| | | | - Michael Weller
- Department of Neurology, University Hospital & University of Zurich, Frauenklinikstrasse 26, CH-8091 Zurich, Switzerland
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30
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Lastraioli E, Lottini T, Iorio J, Freschi G, Fazi M, Duranti C, Carraresi L, Messerini L, Taddei A, Ringressi MN, Salemme M, Villanacci V, Vindigni C, Tomezzoli A, La Mendola R, Bencivenga M, Compagnoni B, Chiudinelli M, Saragoni L, Manzi I, De Manzoni G, Bechi P, Boni L, Arcangeli A. hERG1 behaves as biomarker of progression to adenocarcinoma in Barrett's esophagus and can be exploited for a novel endoscopic surveillance. Oncotarget 2018; 7:59535-59547. [PMID: 27517748 PMCID: PMC5312329 DOI: 10.18632/oncotarget.11149] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 07/09/2016] [Indexed: 12/21/2022] Open
Abstract
Barrett's esophagus (BE) is the only well-known precursor lesion of esophageal adenocarcinoma (EA). The exact estimates of the annual progression rate from BE to EA vary from 0.07% to 3.6%. The identification of BE patients at higher risk to progress to EA is hence mandatory, although difficult to accomplish. In search of novel BE biomarkers we analyzed the efficacy of hERG1 potassium channels in predicting BE progression to EA. Once tested by immunohistochemistry (IHC) on bioptic samples, hERG1 was expressed in BE, and its expression levels increased during progression from BE to esophageal dysplasia (ED) and EA. hERG1 was also over-expressed in the metaplastic cells arising in BE lesions obtained in different BE mouse models, induced either surgically or chemically. Furthermore, transgenic mice which over express hERG1 in the whole gastrointestinal tract, developed BE lesions after an esophago-jejunal anastomosis more frequently, compared to controls. A case-control study was performed on 104 bioptic samples from newly diagnosed BE patients further followed up for at least 10 years. It emerged a statistically significant association between hERG1 expression status and risk of progression to EA. Finally, a novel fluorophore- conjugated recombinant single chain variable fragment antibody (scFv-hERG1-Alexa488) was tested on freshly collected live BE biopsies: it could recognize hERG1 positive samples, perfectly matching IHC data.Overall, hERG1 can be considered a novel BE biomarker to be exploited for a novel endoscopic surveillance protocol, either in biopsies or through endoscopy, to identify those BE patients with higher risk to progress to EA.
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Affiliation(s)
- Elena Lastraioli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Tiziano Lottini
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Jessica Iorio
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Giancarlo Freschi
- Department of Surgery and Translational Medicine, University of Florence, 50134 Florence, Italy
| | - Marilena Fazi
- Department of Surgery and Translational Medicine, University of Florence, 50134 Florence, Italy
| | - Claudia Duranti
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | | | - Luca Messerini
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Antonio Taddei
- Department of Surgery and Translational Medicine, University of Florence, 50134 Florence, Italy
| | - Maria Novella Ringressi
- Department of Surgery and Translational Medicine, University of Florence, 50134 Florence, Italy
| | | | | | - Carla Vindigni
- Pathology Division, Azienda Ospedaliero-Universitaria Senese, 53100 Siena, Italy
| | - Anna Tomezzoli
- Pathology Division, Borgo Trento Hospital, 37134 Verona, Italy
| | | | | | - Bruno Compagnoni
- Surgery Division, Esine Hospital, ASL Vallecamonica Sebino, 25040 Esine (BS), Italy
| | - Mariella Chiudinelli
- Pathology Division, Esine Hospital, ASL Vallecamonica Sebino, 25040 Esine (BS), Italy
| | - Luca Saragoni
- Pathology Division, Morgagni-Pierantoni Hospital, 47121 Forlì, Italy
| | - Ilaria Manzi
- Gastroenterology and Endoscopy Unit, Morgagni-Pierantoni Hospital, 47121 Forlì, Italy
| | | | - Paolo Bechi
- Department of Surgery and Translational Medicine, University of Florence, 50134 Florence, Italy
| | - Luca Boni
- Clinical Trials Coordinating Center, Azienda Ospedaliero-Universitaria Careggi/Istituto Toscano Tumori, 50134 Florence, Italy
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
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31
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McNally BA, Pendon ZD, Trudeau MC. hERG1a and hERG1b potassium channel subunits directly interact and preferentially form heteromeric channels. J Biol Chem 2017; 292:21548-21557. [PMID: 29089383 DOI: 10.1074/jbc.m117.816488] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/24/2017] [Indexed: 01/20/2023] Open
Abstract
Voltage-activated human ether-á-go-go-related gene (hERG) potassium channels are critical for the repolarization of cardiac action potentials and tune-spike frequency adaptation in neurons. Two isoforms of mammalian ERG1 channel subunits, ERG1a and ERG1b, are the principal subunits that conduct the IKr current in the heart and are also broadly expressed in the nervous system. However, there is little direct evidence that ERG1a and ERG1b form heteromeric channels. Here, using electrophysiology, biochemistry, and fluorescence approaches, we systematically tested for direct interactions between hERG1a and hERG1b subunits. We report 1) that hERG1a dominant-negative subunits suppress hERG1b currents (and vice versa), 2) that disulfide bonds form between single cysteine residues experimentally introduced into an extracellular loop of hERG1a and hERG1b subunits and produce hERG1a-hERG1b dimers, and 3) that hERG1a and hERG1b subunits tagged with fluorescent proteins that are FRET pairs exhibit robust energy transfer at the plasma membrane. Thus, multiple lines of evidence indicated a physical interaction between hERG1a and hERG1b, consistent with them forming heteromeric channels. Moreover, co-expression of variable ratios of hERG1a and hERG1b RNA yielded channels with deactivation kinetics that reached a plateau and were different from those of hERG1b channels, consistent with a preference of hERG1b subunits for hERG1a subunits. Cross-linking studies revealed that an equal input of hERG1a and hERG1b yields more hERG1a-hERG1a or hERG1a-hERG1b dimers than hERG1b-hERG1b dimers, also suggesting that hERG1b preferentially interacts with hERG1a. We conclude that hERG1b preferentially forms heteromeric ion channels with hERG1a at the plasma membrane.
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Affiliation(s)
- Beth A McNally
- From the Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Zeus D Pendon
- From the Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Matthew C Trudeau
- From the Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
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Gentile S. hERG1 potassium channel in cancer cells: a tool to reprogram immortality. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 45:649-655. [PMID: 27649700 DOI: 10.1007/s00249-016-1169-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 07/21/2016] [Accepted: 08/30/2016] [Indexed: 12/12/2022]
Abstract
It has been well established that changes in ion fluxes across cellular membranes as a function of time is fundamental in maintaining cellular homeostasis of every living cell. Consequently, dysregulation of ion channels activity is a critical event in pathological conditions of several tissues, including cancer. Nevertheless, the role of ion channels in cancer biology is still not well understood and very little is known about the possible therapeutic opportunities offered by the use of the vast collection of drugs that target ion channels. In this review, we focus on the recent advances in understanding the role of the voltage-gated hERG1 potassium channel in cancer and on the effects of pharmacologic manipulation of the hERG1 in cancer cells aiming to provide insights into the biochemical signaling and cellular processes that are altered by using these drugs.
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Marques-Carvalho MJ, Oppermann J, Muñoz E, Fernandes AS, Gabant G, Cadene M, Heinemann SH, Schönherr R, Morais-Cabral JH. Molecular Insights into the Mechanism of Calmodulin Inhibition of the EAG1 Potassium Channel. Structure 2016; 24:1742-1754. [PMID: 27618660 DOI: 10.1016/j.str.2016.07.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 07/26/2016] [Accepted: 07/29/2016] [Indexed: 12/26/2022]
Abstract
The human EAG1 potassium channel belongs to the superfamily of KCNH voltage-gated potassium channels that have roles in cardiac repolarization and neuronal excitability. EAG1 is strongly inhibited by Ca2+/calmodulin (CaM) through a mechanism that is not understood. We determined the binding properties of CaM with each one of three previously identified binding sites (BDN, BDC1, and BDC2), analyzed binding to protein stretches that include more than one site, and determined the effect of neighboring globular domains on the binding properties. The determination of the crystal structure of CaM bound to BDC2 shows the channel fragment interacting with only the C lobe of calmodulin and adopting an unusual bent conformation. Based on this structure and on a functional and biochemical analysis of mutants, we propose a model for the mechanism of inhibition whereby the local conformational change induced by CaM binding at BDC2 lies at the basis of channel modulation.
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Affiliation(s)
- Maria João Marques-Carvalho
- Instituto de Biologia Molecular e Celular, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Johannes Oppermann
- Department of Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University Jena and Jena University Hospital, 07745 Jena, Germany
| | - Eva Muñoz
- Software 4 Science Developments, 15782 Santiago de Compostela, Spain
| | - Andreia S Fernandes
- Instituto de Biologia Molecular e Celular, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Guillaume Gabant
- Centre de Biophysique Moléculaire, CNRS UPR430, 45071 Orléans, France
| | - Martine Cadene
- Centre de Biophysique Moléculaire, CNRS UPR430, 45071 Orléans, France
| | - Stefan H Heinemann
- Department of Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University Jena and Jena University Hospital, 07745 Jena, Germany
| | - Roland Schönherr
- Department of Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University Jena and Jena University Hospital, 07745 Jena, Germany
| | - João Henrique Morais-Cabral
- Instituto de Biologia Molecular e Celular, Rua Alfredo Allen, 208, 4200-135 Porto, Portugal; Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal.
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Fernández-Valle Á, Rodrigo JP, Rodríguez-Santamarta T, Villaronga MÁ, Álvarez-Teijeiro S, García-Pedrero JM, Suárez-Fernández L, Lequerica-Fernández P, de Vicente JC. HERG1 potassium channel expression in potentially malignant disorders of the oral mucosa and prognostic relevance in oral squamous cell carcinoma. Head Neck 2016; 38:1672-1678. [DOI: 10.1002/hed.24493] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 02/24/2016] [Accepted: 03/21/2016] [Indexed: 01/17/2023] Open
Affiliation(s)
- Álvaro Fernández-Valle
- Department of Oral and Maxillofacial Surgery; Hospital Universitario Central de Asturias (HUCA); Oviedo Asturias Spain
| | - Juan Pablo Rodrigo
- Department of Otolaryngology; Hospital Universitario Central de Asturias (HUCA); Oviedo Asturias Spain
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA); Hospital Universitario Central de Asturias, Edificio Consultas Externas, Planta Baja Lab 2 ORL-IUOPA; Oviedo Asturias Spain
| | - Tania Rodríguez-Santamarta
- Department of Oral and Maxillofacial Surgery; Hospital Universitario Central de Asturias (HUCA); Oviedo Asturias Spain
| | - M. Ángeles Villaronga
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA); Hospital Universitario Central de Asturias, Edificio Consultas Externas, Planta Baja Lab 2 ORL-IUOPA; Oviedo Asturias Spain
| | - Saúl Álvarez-Teijeiro
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA); Hospital Universitario Central de Asturias, Edificio Consultas Externas, Planta Baja Lab 2 ORL-IUOPA; Oviedo Asturias Spain
| | - Juana M. García-Pedrero
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA); Hospital Universitario Central de Asturias, Edificio Consultas Externas, Planta Baja Lab 2 ORL-IUOPA; Oviedo Asturias Spain
| | - Laura Suárez-Fernández
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA); Hospital Universitario Central de Asturias, Edificio Consultas Externas, Planta Baja Lab 2 ORL-IUOPA; Oviedo Asturias Spain
| | | | - Juan Carlos de Vicente
- Department of Oral and Maxillofacial Surgery; Hospital Universitario Central de Asturias (HUCA); Oviedo Asturias Spain
- Instituto Universitario de Oncología del Principado de Asturias (IUOPA); Hospital Universitario Central de Asturias, Edificio Consultas Externas, Planta Baja Lab 2 ORL-IUOPA; Oviedo Asturias Spain
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Lu L, Du W, Liu W, Guo D, He X, Li H. Increased expression of HERG K + channels contributes to myelodysplastic syndrome progression and displays correlation with prognosis stratification. ACTA ACUST UNITED AC 2016; 21:583-592. [PMID: 27077769 DOI: 10.1080/10245332.2016.1151603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVES Human ether-a-go-go-related gene (HERG) K+ channels are shown to be aberrantly expressed in a variety of cancer cells where they play roles in contributing to cancer progression. Myelodysplastic syndromes (MDS) are a group of clinical heterogeneous disorders characterized by bone marrow failure and dysplasia of blood cells. However, the involvement of HERG K+ channels in MDS development is poorly understood. METHODS The expression of HERG K+ channels in untreated MDS, acute myeloid leukemia (AML) patients and the control group was detected by flow cytometry. The roles of HERG K+ channels in regulation of SKM-1 cell proliferation, apoptosis, and cell cycle were determined by CCK-8 assay and flow cytometry, respectively. RESULTS We found that expression of HERG K+ channels in MDS patients was significantly higher than controls and was lower than AML. Percentage of HERG K+ channels on CD34+CD38- cells gradually increased from controls to high-grade MDS subtypes. And HERG K+ channel levels showed an ascending tendency from low-risk to high-risk MDS group. In addition, the CCK-8 assay, apoptosis and cell cycle analysis were performed and showed that blockage of HERG K+ channels decreased the proliferation of MDS cells but rarely had effects on cell apoptosis and cell cycle distribution. CONCLUSION Our study demonstrated that HERG K+ channels might be a potential tumor marker of MDS. These channels were likely to contribute to MDS progression and were helpful for predicting prognosis of MDS. Inhibition of HERG K+ channels might be a novel therapeutic measure for MDS.
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Affiliation(s)
- Li Lu
- a Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Wen Du
- a Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Wei Liu
- a Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Dongmei Guo
- a Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Xiaoqi He
- a Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
| | - Huiyu Li
- a Union Hospital, Tongji Medical College, Huazhong University of Science and Technology , Wuhan , China
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Menéndez ST, Villaronga MÁ, Rodrigo JP, Álvarez-Teijeiro S, Urdinguio RG, Fraga MF, Suárez C, García-Pedrero JM. HERG1A potassium channel is the predominant isoform in head and neck squamous cell carcinomas: evidence for regulation by epigenetic mechanisms. Sci Rep 2016; 6:19666. [PMID: 26785772 PMCID: PMC4726400 DOI: 10.1038/srep19666] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/16/2015] [Indexed: 11/09/2022] Open
Abstract
Evidences indicate that HERG1 voltage-gated potassium channel is frequently aberrantly expressed in various cancers including head and neck squamous cell carcinomas (HNSCC), representing a clinically and biologically relevant feature during disease progression and a potential therapeutic target. The present study further and significantly extends these data investigating for the first time the expression and individual contribution of HERG1 isoforms, their clinical significance during disease progression and also the underlying regulatory mechanisms. Analysis of HERG1A and HERG1B expression using real-time RT-PCR consistently showed that HERG1A is the predominant isoform in ten HNSCC-derived cell lines tested. HERG2 and HERG3 were also detected. Immunohistochemical analysis of HERG1A expression on 133 HNSCC specimens demonstrated that HERG1A expression increased during tumour progression and correlated significantly with reduced disease-specific survival. Furthermore, our study provides original evidence supporting the involvement of histone acetylation (i.e. H3Ac and H4K16Ac activating marks) in the regulation of HERG1 expression in HNSCC. Interestingly, this mechanism was also found to regulate the expression of another oncogenic channel (Kv3.4) as well as HERG2 and HERG3. These data demonstrate that HERG1A is the predominant and disease-relevant isoform in HNSCC progression, while histone acetylation emerges as an important regulatory mechanism underlying Kv gene expression.
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Affiliation(s)
- Sofía T Menéndez
- Servicio de Otorrinolaringología, Hospital Universitario Central de Asturias and Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
| | - M Ángeles Villaronga
- Servicio de Otorrinolaringología, Hospital Universitario Central de Asturias and Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
| | - Juan P Rodrigo
- Servicio de Otorrinolaringología, Hospital Universitario Central de Asturias and Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
| | - Saúl Álvarez-Teijeiro
- Servicio de Otorrinolaringología, Hospital Universitario Central de Asturias and Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
| | - Rocío G Urdinguio
- Unidad de Epigenética del Cáncer, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Spain
| | - Mario F Fraga
- Unidad de Epigenética del Cáncer, Instituto Universitario de Oncología del Principado de Asturias, Universidad de Oviedo, Spain.,Department of Immunology and Oncology, National Center for Biotechnology, CNB-CSIC, Cantoblanco, Madrid E-28049, Spain
| | - Carlos Suárez
- Servicio de Otorrinolaringología, Hospital Universitario Central de Asturias and Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
| | - Juana M García-Pedrero
- Servicio de Otorrinolaringología, Hospital Universitario Central de Asturias and Instituto Universitario de Oncología del Principado de Asturias, Oviedo, Spain
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Effects of Tannic Acid, Green Tea and Red Wine on hERG Channels Expressed in HEK293 Cells. PLoS One 2015; 10:e0143797. [PMID: 26625122 PMCID: PMC4666621 DOI: 10.1371/journal.pone.0143797] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/10/2015] [Indexed: 02/01/2023] Open
Abstract
Tannic acid presents in varying concentrations in plant foods, and in relatively high concentrations in green teas and red wines. Human ether-à-go-go-related gene (hERG) channels expressed in multiple tissues (e.g. heart, neurons, smooth muscle and cancer cells), and play important roles in modulating cardiac action potential repolarization and tumor cell biology. The present study investigated the effects of tannic acid, green teas and red wines on hERG currents. The effects of tannic acid, teas and red wines on hERG currents stably transfected in HEK293 cells were studied with a perforated patch clamp technique. In this study, we demonstrated that tannic acid inhibited hERG currents with an IC50 of 3.4 μM and ~100% inhibition at higher concentrations, and significantly shifted the voltage dependent activation to more positive potentials (Δ23.2 mV). Remarkably, a 100-fold dilution of multiple types of tea (green tea, oolong tea and black tea) or red wine inhibited hERG currents by ~90%, and significantly shifted the voltage dependent activation to more positive potentials (Δ30.8 mV and Δ26.0 mV, respectively). Green tea Lung Ching and red wine inhibited hERG currents, with IC50 of 0.04% and 0.19%, respectively. The effects of tannic acid, teas and red wine on hERG currents were irreversible. These results suggest tannic acid is a novel hERG channel blocker and consequently provide a new mechanistic evidence for understanding the effects of tannic acid. They also revealed the potential pharmacological basis of tea- and red wine-induced biology activities.
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Perez-Neut M, Shum A, Cuevas BD, Miller R, Gentile S. Stimulation of hERG1 channel activity promotes a calcium-dependent degradation of cyclin E2, but not cyclin E1, in breast cancer cells. Oncotarget 2015; 6:1631-9. [PMID: 25596745 PMCID: PMC4359320 DOI: 10.18632/oncotarget.2829] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 11/27/2014] [Indexed: 01/28/2023] Open
Abstract
Cyclin E2 gene amplification, but not cyclin E1, has been recently defined as marker for poor prognosis in breast cancer, and appears to play a major role in proliferation and therapeutic resistance in several breast cancer cells. Our laboratory has previously reported that stimulation of the hERG1 potassium channel with selective activators led to down-regulation of cyclin E2 in breast cancer cells. In this work, we demonstrate that stimulation of hERG1 promotes an ubiquitin-proteasome-dependent degradation of cyclin E2 in multiple breast cancer cell lines representing Luminal A, HER2+ and Trastuzumab-resistant breast cancer cells. In addition we have also reveal that hERG1 stimulation induces an increase in intracellular calcium that is required for cyclin E2 degradation. This novel function for hERG1 activity was specific for cyclin E2, as cyclins A, B, D E1 were unaltered by the treatment. Our results reveal a novel mechanism by which hERG1 activation impacts the tumor marker cyclin E2 that is independent of cyclin E1, and suggest a potential therapeutic use for hERG1 channel activators.
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Affiliation(s)
- Mathew Perez-Neut
- Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Maywood, IL, USA
| | - Andrew Shum
- Department of Pharmacology, Northwestern University, Chicago, IL, USA
| | - Bruce D Cuevas
- Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Maywood, IL, USA
| | - Richard Miller
- Department of Pharmacology, Northwestern University, Chicago, IL, USA
| | - Saverio Gentile
- Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Maywood, IL, USA
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Hu L, Li LL, Lin ZG, Jiang ZC, Li HX, Zhao SG, Yang KB. Blockage of potassium channel inhibits proliferation of glioma cells via increasing reactive oxygen species. Oncol Res 2015; 22:57-65. [PMID: 25700359 PMCID: PMC7592800 DOI: 10.3727/096504014x14098532393518] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The potassium (K+) channel plays an important role in the cell cycle and proliferation of tumor cells, while its role in brain glioma cells and the signaling pathways remains unclear. We used tetraethylammonium (TEA), a nonselective antagonist of big conductance K+ channels, to block K+ channels in glioma cells, and antioxidant N-acetyl-l-cysteine (NAC) to inhibit production of intracellular reactive oxygen species (ROS). TEA showed an antiproliferation effect on C6 and U87 glioma cells in a time-dependent manner, which was accompanied by an increased intracellular ROS level. Antioxidant NAC pretreatment reversed TEA-mediated antiproliferation and restored ROS level. TEA treatment also caused significant increases in mRNA and protein levels of tumor-suppressor proteins p53 and p21, and the upregulation was attenuated by pretreatment of NAC. Our results suggest that K+ channel activity significantly contributes to brain glioma cell proliferation via increasing ROS, and it might be an upstream factor triggering the activation of the p53/p21Cip1-dependent signaling pathway, consequently leading to glioma cell cycle arrest.
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Affiliation(s)
- Li Hu
- Department of Neurosurgery, the First Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Li-Li Li
- Department of Neurosurgery, the First Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Zhi-Guo Lin
- Department of Neurosurgery, the First Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Zhi-Chao Jiang
- Department of Neurosurgery, the First Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Hong-Xing Li
- Department of Neurosurgery, the First Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Shi-Guang Zhao
- Department of Neurosurgery, the First Affiliated Hospital of Harbin Medical UniversityHarbinChina
| | - Kong-Bin Yang
- Department of Neurosurgery, the First Affiliated Hospital of Harbin Medical UniversityHarbinChina
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hERG1 Potassium Channels: Novel Biomarkers in Human Solid Cancers. BIOMED RESEARCH INTERNATIONAL 2015; 2015:896432. [PMID: 26339650 PMCID: PMC4538961 DOI: 10.1155/2015/896432] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 02/16/2015] [Accepted: 02/24/2015] [Indexed: 01/05/2023]
Abstract
Because of their high incidence and mortality solid cancers are a major health problem worldwide. Although several new biomarkers and potential targets for therapy have been identified through biomolecular research in the last years, the effects on patients' outcome are still unsatisfactory. Increasing evidence indicates that hERG1 potassium channels are overexpressed in human primary cancers of different origin and several associations between hERG1 expression and clinicopathological features and/or outcome are emerging. Aberrant hERG1 expression may be exploited either for early diagnosis (especially in those cancers where it is expressed in the initial steps of tumor progression) or for therapy purposes. Indeed, hERG1 blockage impairs tumor cell growth both in vitro and in vivo in preclinical mouse model. hERG1-based tumor therapy in humans, however, encounters the major hindrance of the potential cardiotoxicity that many hERG1 blockers exert. In this review we focus on recent advances in translational research in some of the most frequent human solid cancers (breast, endometrium, ovary, pancreas, esophagus, stomach, and colorectum) that have been shown to express hERG1 and that are a major health problem.
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Arcangeli A, Becchetti A. Novel perspectives in cancer therapy: Targeting ion channels. Drug Resist Updat 2015; 21-22:11-9. [DOI: 10.1016/j.drup.2015.06.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 06/24/2015] [Accepted: 06/27/2015] [Indexed: 01/04/2023]
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Erdem M, Tekiner TA, Fejzullahu A, Akan G, Anak S, Saribeyoglu ET, Ozbek U, Atalar F. herg1b expression as a potential specific marker in pediatric acute myeloid leukemia patients with HERG 897K/K genotype. Pediatr Hematol Oncol 2015; 32:182-92. [PMID: 25247487 DOI: 10.3109/08880018.2014.949941] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Human ether-a-go-go related gene (herg) encoding HERG K(+) channel has been demonstrated in many previous studies with its association to cell cycle progression and growth in tumor cells. The upregulated expression of HERG K+ channels was determined in different tumor types. Furthermore, not only full-length transcript herg1 but also a truncated isoform herg1b was shown to be expressed in cancer cells. In this study, the expression levels of herg1 and herg1b and the impact of K897T mutation on their expressions were investigated in pediatric acute myeloid leukemia (pAML). Expression levels of herg1 and herg1b isoforms were analyzed by quantitative real time polymerase chain reaction (PCR) in pAML patients together with healthy donors, and their expressions were confirmed by western blotting. The 2690 A>C nucleotide variation in KCNH2 gene corresponding to K897T amino acid change was analyzed by PCR followed by restriction enzyme digestion. herg1b overexpression was observed in tumor cells compared to healthy controls (P = .0024). However, herg1 expression was higher in healthy control cells than tumor cells (P = .001). The prevalence of polymorphic allele 897T was 26% in our patient group and 897T carriers showed increased herg1b expression compared to wild-type allele carriers. Our results demonstrate the presence of the increased levels of herg1b expression in pAML. In addition, we report for the first time that, pAML subgroup with HERG 897K/K genotype compared to 897K/T and T/T genotypes express increased levels of herg1b. In conclusion, HERG 897K/K genotype with increased level of herg1b expression might well be a prognostic marker for pAML.
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Affiliation(s)
- Merve Erdem
- Department of Growth-Development and Pediatric Endocrinology, Child Health Institute, Istanbul University , Capa, Istanbul , Turkey
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Wang Y, Wang L, Yin C, An B, Hao Y, Wei T, Li L, Song G. Arsenic trioxide inhibits breast cancer cell growth via microRNA-328/hERG pathway in MCF-7 cells. Mol Med Rep 2015; 12:1233-8. [PMID: 25824027 DOI: 10.3892/mmr.2015.3558] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 03/03/2015] [Indexed: 11/05/2022] Open
Abstract
Arsenic trioxide (As2O3) has been widely used in the treatment of acute promyelocytic leukemia and has been observed to exhibit therapeutic effects in various types of solid tumor. In a previous study by this group, it was shown that As2O3 induces the apoptosis of MCF-7 breast cancer cells through inhibition of the human ether-à-go-go-related gene (hERG) channel. The present study was designed to further investigate the effect of As2O3 on breast cancer cells and to examine the mechanism underlying the regulation of hERG expression. The present study confirmed that As2O3 inhibited tumor growth in vivo, following MCF-7 cell implantation into nude mice. Using computational prediction , it was identified that microRNA (miR)-328 had a binding site in the 3'-untranslated region of hERG mRNA. A luciferase activity assay demonstrated that hERG is a target gene of miR-328. Further investigation using western blot analysis and reverse transcription-quantitative polymerase chain reaction revealed that As2O3 downregulated hERG expression via upregulation of miR-328 expression in MCF-7 cells. In conclusion, As2O3 was observed to inhibit breast cancer cell growth, at least in part, through the miR-328/hERG pathway.
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Affiliation(s)
- Ying Wang
- Medical Functional Laboratory, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
| | - Leqiu Wang
- Department of Otolaryngology, Hongqi Hospital of Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
| | - Changhao Yin
- Department of Neurology, Hongqi Hospital of Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
| | - Baizhu An
- Department of Anatomy, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
| | - Yankun Hao
- Medical Functional Laboratory, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
| | - Tao Wei
- Medical Functional Laboratory, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
| | - Li Li
- Medical Functional Laboratory, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
| | - Gaochen Song
- Medical Functional Laboratory, Mudanjiang Medical University, Mudanjiang, Heilongjiang 157011, P.R. China
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Placing ion channels into a signaling network of T cells: from maturing thymocytes to healthy T lymphocytes or leukemic T lymphoblasts. BIOMED RESEARCH INTERNATIONAL 2015; 2015:750203. [PMID: 25866806 PMCID: PMC4383400 DOI: 10.1155/2015/750203] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 09/19/2014] [Indexed: 12/20/2022]
Abstract
T leukemogenesis is a multistep process, where the genetic errors during T cell maturation cause the healthy progenitor to convert into the leukemic precursor that lost its ability to differentiate but possesses high potential for proliferation, self-renewal, and migration. A new misdirecting "leukemogenic" signaling network appears, composed by three types of participants which are encoded by (1) genes implicated in determined stages of T cell development but deregulated by translocations or mutations, (2) genes which normally do not participate in T cell development but are upregulated, and (3) nondifferentially expressed genes which become highly interconnected with genes expressed differentially. It appears that each of three groups may contain genes coding ion channels. In T cells, ion channels are implicated in regulation of cell cycle progression, differentiation, activation, migration, and cell death. In the present review we are going to reveal a relationship between different genetic defects, which drive the T cell neoplasias, with calcium signaling and ion channels. We suggest that changes in regulation of various ion channels in different types of the T leukemias may provide the intracellular ion microenvironment favorable to maintain self-renewal capacity, arrest differentiation, induce proliferation, and enhance motility.
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Involvement of potassium channels in the progression of cancer to a more malignant phenotype. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:2477-92. [PMID: 25517985 DOI: 10.1016/j.bbamem.2014.12.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 12/01/2014] [Accepted: 12/08/2014] [Indexed: 12/22/2022]
Abstract
Potassium channels are a diverse group of pore-forming transmembrane proteins that selectively facilitate potassium flow through an electrochemical gradient. They participate in the control of the membrane potential and cell excitability in addition to different cell functions such as cell volume regulation, proliferation, cell migration, angiogenesis as well as apoptosis. Because these physiological processes are essential for the correct cell function, K+ channels have been associated with a growing number of diseases including cancer. In fact, different K+ channel families such as the voltage-gated K+ channels, the ether à-go-go K+ channels, the two pore domain K+ channels and the Ca2+-activated K+ channels have been associated to tumor biology. Potassium channels have a role in neoplastic cell-cycle progression and their expression has been found abnormal in many types of tumors and cancer cells. In addition, the expression and activity of specific K+ channels have shown a significant correlation with the tumor malignancy grade. The aim of this overview is to summarize published data on K+ channels that exhibit oncogenic properties and have been linked to a more malignant cancer phenotype. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.
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Large-scale mutational analysis of Kv11.1 reveals molecular insights into type 2 long QT syndrome. Nat Commun 2014; 5:5535. [PMID: 25417810 PMCID: PMC4243539 DOI: 10.1038/ncomms6535] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 10/09/2014] [Indexed: 12/23/2022] Open
Abstract
It has been suggested that deficient protein trafficking to the cell membrane is the dominant mechanism associated with type 2 Long QT syndrome (LQT2) caused by Kv11.1 potassium channel missense mutations, and that for many mutations the trafficking defect can be corrected pharmacologically. However, this inference was based on expression of a small number of Kv11.1 mutations. We performed a comprehensive analysis of 167 LQT2-linked missense mutations in four Kv11.1 structural domains and found that deficient protein trafficking is the dominant mechanism for all domains except for the distal carboxy-terminus. Also, most pore mutations--in contrast to intracellular domain mutations--were found to have severe dominant-negative effects when co-expressed with wild-type subunits. Finally, pharmacological correction of the trafficking defect in homomeric mutant channels was possible for mutations within all structural domains. However, pharmacological correction is dramatically improved for pore mutants when co-expressed with wild-type subunits to form heteromeric channels.
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Gasparoli L, D'Amico M, Masselli M, Pillozzi S, Caves R, Khuwaileh R, Tiedke W, Mugridge K, Pratesi A, Mitcheson JS, Basso G, Becchetti A, Arcangeli A. New pyrimido-indole compound CD-160130 preferentially inhibits the KV11.1B isoform and produces antileukemic effects without cardiotoxicity. Mol Pharmacol 2014; 87:183-96. [PMID: 25411366 DOI: 10.1124/mol.114.094920] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
KV11.1 (hERG1) channels are often overexpressed in human cancers. In leukemias, KV11.1 regulates pro-survival signals that promote resistance to chemotherapy, raising the possibility that inhibitors of KV11.1 could be therapeutically beneficial. However, because of the role of KV11.1 in cardiac repolarization, blocking these channels may cause cardiac arrhythmias. We show that CD-160130, a novel pyrimido-indole compound, blocks KV11.1 channels with a higher efficacy for the KV11.1 isoform B, in which the IC50 (1.8 μM) was approximately 10-fold lower than observed in KV11.1 isoform A. At this concentration, CD-160130 also had minor effects on Kir2.1, KV 1.3, Kv1.5, and KCa3.1. In vitro, CD-160130 induced leukemia cell apoptosis, and could overcome bone marrow mesenchymal stromal cell (MSC)-induced chemoresistance. This effect was caused by interference with the survival signaling pathways triggered by MSCs. In vivo, CD-160130 produced an antileukemic activity, stronger than that caused by cytarabine. Consistent with its atypical target specificity, CD-160130 did not bind to the main binding site of the arrhythmogenic KV11.1 blockers (the Phe656 pore residue). Importantly, in guinea pigs CD-160130 produced neither alteration of the cardiac action potential shape in dissociated cardiomyocytes nor any lengthening of the QT interval in vivo. Moreover, CD-160130 had no myelotoxicity on human bone marrow-derived cells. Therefore, CD-160130 is a promising first-in-class compound to attempt oncologic therapy without cardiotoxicity, based on targeting KV11.1. Because leukemia and cardiac cells tend to express different ratios of the A and B KV11.1 isoforms, the pharmacological properties of CD-160130 may depend, at least in part, on isoform specificity.
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Affiliation(s)
- Luca Gasparoli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Massimo D'Amico
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Marika Masselli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Serena Pillozzi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Rachel Caves
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Rawan Khuwaileh
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Wolfgang Tiedke
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Kenneth Mugridge
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Alessandro Pratesi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - John S Mitcheson
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Giuseppe Basso
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Andrea Becchetti
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy (L.G., S.P., A.A.); Department of Chemistry "Ugo Schiff," University of Florence, Florence, Italy (M.M., A.P.); DI.V.A.L. Toscana srl, Sesto Fiorentino, Italy (M.D.A., M.M.); Department of Cell Physiology and Pharmacology, University of Leicester, Leicester, United Kingdom (R.C., R.K., J.S.M.); BlackSwan Pharma GmbH, Leipzig, Germany (W.T., K.M.); Oncohematology Laboratory, Department of Woman and Child Health, University of Padova, Padova, Italy (G.B.); and Department of Biotechnologies and Biosciences, University of Milano-Bicocca, Milan, Italy (A.B.)
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48
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Cervera J, Alcaraz A, Mafe S. Membrane potential bistability in nonexcitable cells as described by inward and outward voltage-gated ion channels. J Phys Chem B 2014; 118:12444-50. [PMID: 25286866 DOI: 10.1021/jp508304h] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The membrane potential of nonexcitable cells, defined as the electrical potential difference between the cell cytoplasm and the extracellular environment when the current is zero, is controlled by the individual electrical conductance of different ion channels. In particular, inward- and outward-rectifying voltage-gated channels are crucial for cell hyperpolarization/depolarization processes, being amenable to direct physical study. High (in absolute value) negative membrane potentials are characteristic of terminally differentiated cells, while low membrane potentials are found in relatively depolarized, more plastic cells (e.g., stem, embryonic, and cancer cells). We study theoretically the hyperpolarized and depolarized values of the membrane potential, as well as the possibility to obtain a bistability behavior, using simplified models for the ion channels that regulate this potential. The bistability regions, which are defined in the multidimensional state space determining the cell state, can be relevant for the understanding of the different model cell states and the transitions between them, which are triggered by changes in the external environment.
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Affiliation(s)
- Javier Cervera
- Departament de Termodinàmica, Universitat de València , E-46100 Burjassot, Spain
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49
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Abstract
Potassium channels are pore-forming transmembrane proteins that regulate a multitude of biological processes by controlling potassium flow across cell membranes. Aberrant potassium channel functions contribute to diseases such as epilepsy, cardiac arrhythmia, and neuromuscular symptoms collectively known as channelopathies. Increasing evidence suggests that cancer constitutes another category of channelopathies associated with dysregulated channel expression. Indeed, potassium channel–modulating agents have demonstrated antitumor efficacy. Potassium channels regulate cancer cell behaviors such as proliferation and migration through both canonical ion permeation–dependent and noncanonical ion permeation–independent functions. Given their cell surface localization and well-known pharmacology, pharmacological strategies to target potassium channel could prove to be promising cancer therapeutics.
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Affiliation(s)
- Xi Huang
- Howard Hughes Medical Institute, Department of Physiology, and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158Howard Hughes Medical Institute, Department of Physiology, and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158Howard Hughes Medical Institute, Department of Physiology, and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
| | - Lily Yeh Jan
- Howard Hughes Medical Institute, Department of Physiology, and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158Howard Hughes Medical Institute, Department of Physiology, and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158Howard Hughes Medical Institute, Department of Physiology, and Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158
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50
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Mitcheson J, Arcangeli A. The Therapeutic Potential of hERG1 K+ Channels for Treating Cancer and Cardiac Arrhythmias. ION CHANNEL DRUG DISCOVERY 2014. [DOI: 10.1039/9781849735087-00258] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
hERG potassium channels present pharmacologists and medicinal chemists with a dilemma. On the one hand hERG is a major reason for drugs being withdrawn from the market because of drug induced long QT syndrome and the associated risk of inducing sudden cardiac death, and yet hERG blockers are still widely used in the clinic to treat cardiac arrhythmias. Moreover, in the last decade overwhelming evidence has been provided that hERG channels are aberrantly expressed in cancer cells and that they contribute to tumour cell proliferation, resistance to apoptosis, and neoangiogenesis. Here we provide an overview of the properties of hERG channels and their role in excitable cells of the heart and nervous system as well as in cancer. We consider the therapeutic potential of hERG, not only with regard to the negative impact due to drug induced long QT syndrome, but also its future potential as a treatment in the fight against cancer.
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Affiliation(s)
- John Mitcheson
- University of Leicester, Department of Cell Physiology and Pharmacology, Medical Sciences Building University Road Leicester LE1 9HN UK
| | - Annarosa Arcangeli
- Department of Experimental Pathology and Oncology, University of Florence Viale GB Morgagni, 50 50134 Firenze Italy
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