1
|
Intracellular hemin is a potent inhibitor of the voltage-gated potassium channel Kv10.1. Sci Rep 2022; 12:14645. [PMID: 36030326 PMCID: PMC9420133 DOI: 10.1038/s41598-022-18975-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 08/23/2022] [Indexed: 11/08/2022] Open
Abstract
Heme, an iron-protoporphyrin IX complex, is a cofactor bound to various hemoproteins and supports a broad range of functions, such as electron transfer, oxygen transport, signal transduction, and drug metabolism. In recent years, there has been a growing recognition of heme as a non-genomic modulator of ion channel functions. Here, we show that intracellular free heme and hemin modulate human ether à go-go (hEAG1, Kv10.1) voltage-gated potassium channels. Application of hemin to the intracellular side potently inhibits Kv10.1 channels with an IC50 of about 4 nM under ambient and 63 nM under reducing conditions in a weakly voltage-dependent manner, favoring inhibition at resting potential. Functional studies on channel mutants and biochemical analysis of synthetic and recombinant channel fragments identified a heme-binding motif CxHx8H in the C-linker region of the Kv10.1 C terminus, with cysteine 541 and histidines 543 and 552 being important for hemin binding. Binding of hemin to the C linker may induce a conformational constraint that interferes with channel gating. Our results demonstrate that heme and hemin are endogenous modulators of Kv10.1 channels and could be exploited to modulate Kv10.1-mediated cellular functions.
Collapse
|
2
|
Luis E, Anaya-Hernández A, León-Sánchez P, Durán-Pastén ML. The Kv10.1 Channel: A Promising Target in Cancer. Int J Mol Sci 2022; 23:ijms23158458. [PMID: 35955591 PMCID: PMC9369319 DOI: 10.3390/ijms23158458] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/25/2022] [Accepted: 07/27/2022] [Indexed: 12/19/2022] Open
Abstract
Carcinogenesis is a multistage process involving the dysregulation of multiple genes, proteins, and pathways that make any normal cell acquire a cancer cell phenotype. Therefore, it is no surprise that numerous ion channels could be involved in this process. Since their discovery and subsequent cloning, ion channels have been established as therapeutic targets in excitable cell pathologies (e.g., cardiac arrhythmias or epilepsy); however, their involvement in non-excitable cell pathologies is relatively recent. Among all ion channels, the voltage-gated potassium channels Kv10.1 have been established as a promising target in cancer treatment due to their high expression in tumoral tissues compared to low levels in healthy tissues.
Collapse
Affiliation(s)
- Enoch Luis
- Cátedras CONACYT—Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, C.U., Ciudad de México 04510, Mexico
- Laboratorio Nacional de Canalopatías, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, C.U., Ciudad de México 04510, Mexico; (P.L.-S.); (M.L.D.-P.)
- Correspondence:
| | - Arely Anaya-Hernández
- Centro de Investigación en Genética y Ambiente, Universidad Autónoma de Tlaxcala, Km. 10.5 Autopista Tlaxcala-San Martín, Tlaxcala 90120, Mexico;
| | - Paulina León-Sánchez
- Laboratorio Nacional de Canalopatías, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, C.U., Ciudad de México 04510, Mexico; (P.L.-S.); (M.L.D.-P.)
| | - María Luisa Durán-Pastén
- Laboratorio Nacional de Canalopatías, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Circuito Exterior s/n, C.U., Ciudad de México 04510, Mexico; (P.L.-S.); (M.L.D.-P.)
| |
Collapse
|
3
|
Iorio J, Lastraioli L, Lastraioli E. Potassium in Solid Cancers. Physiology (Bethesda) 2022. [DOI: 10.5772/intechopen.101108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Electrolyte disorders are a frequent finding in cancer patients. In the majority of cases the etiologies of such disorders are common to all cancer types (i.e. diuretic-induced hyponatremia or hypokalemia). Sometimes, electrolyte disorders are caused by paraneoplastic syndromes or are due to cancer therapy. Potassium is one of the most important electrolytes of the human body since it is involved in the regulation of muscle contraction, maintenance of the integrity of the skeleton, blood pressure and nerve transmission as well as in the normal function of cells. Potassium homeostasis is strictly regulated since the gap between the recommended daily dietary intake (120 mEq/day) and the levels stored in the extracellular fluid (around 70 mEq) is huge. Alterations of potassium homeostasis are frequent in cancer patients as well alterations in potassium channels, the transmembrane proteins that mediate potassium fluxes within the cells. The present chapter is focused on the clinical significance of potassium homeostasis and potassium channels in patients with solid tumors.
Collapse
|
4
|
How Dysregulated Ion Channels and Transporters Take a Hand in Esophageal, Liver, and Colorectal Cancer. Rev Physiol Biochem Pharmacol 2020; 181:129-222. [PMID: 32875386 DOI: 10.1007/112_2020_41] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Over the last two decades, the understanding of how dysregulated ion channels and transporters are involved in carcinogenesis and tumor growth and progression, including invasiveness and metastasis, has been increasing exponentially. The present review specifies virtually all ion channels and transporters whose faulty expression or regulation contributes to esophageal, hepatocellular, and colorectal cancer. The variety reaches from Ca2+, K+, Na+, and Cl- channels over divalent metal transporters, Na+ or Cl- coupled Ca2+, HCO3- and H+ exchangers to monocarboxylate carriers and organic anion and cation transporters. In several cases, the underlying mechanisms by which these ion channels/transporters are interwoven with malignancies have been fully or at least partially unveiled. Ca2+, Akt/NF-κB, and Ca2+- or pH-dependent Wnt/β-catenin signaling emerge as cross points through which ion channels/transporters interfere with gene expression, modulate cell proliferation, trigger epithelial-to-mesenchymal transition, and promote cell motility and metastasis. Also miRs, lncRNAs, and DNA methylation represent potential links between the misexpression of genes encoding for ion channels/transporters, their malfunctioning, and cancer. The knowledge of all these molecular interactions has provided the basis for therapeutic strategies and approaches, some of which will be broached in this review.
Collapse
|
5
|
Movsisyan N, Pardo LA. Kv10.1 Regulates Microtubule Dynamics during Mitosis. Cancers (Basel) 2020; 12:cancers12092409. [PMID: 32854244 PMCID: PMC7564071 DOI: 10.3390/cancers12092409] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/13/2020] [Accepted: 08/18/2020] [Indexed: 12/16/2022] Open
Abstract
Kv10.1 (potassium voltage-gated channel subfamily H member 1, known as EAG1 or Ether-à-go-go 1), is a voltage-gated potassium channel, prevailingly expressed in the central nervous system. The aberrant expression of Kv10.1 is detected in over 70% of all human tumor tissues and correlates with poorer prognosis. In peripheral tissues, Kv10.1 is expressed almost exclusively during the G2/M phase of the cell cycle and regulates its progression-downregulation of Kv10.1 extends the duration of the G2/M phase both in cancer and healthy cells. Here, using biochemical and imaging techniques, such as live-cell measurements of microtubule growth and of cytosolic calcium, we elucidate the mechanisms of Kv10.1-mediated regulation at the G2/M phase. We show that Kv10.1 has a dual effect on mitotic microtubule dynamics. Through the functional interaction with ORAI1 (calcium release-activated calcium channel protein 1), it modulates cytosolic calcium oscillations, thereby changing microtubule behavior. The inhibition of either Kv10.1 or ORAI1 stabilizes the microtubules. In contrast, the knockdown of Kv10.1 increases the dynamicity of mitotic microtubules, resulting in a stronger spindle assembly checkpoint, greater mitotic spindle angle, and a decrease in lagging chromosomes. Understanding of Kv10.1-mediated modulation of the microtubule architecture will help to comprehend how cancer tissue benefits from the presence of Kv10.1, and thereby increase the efficacy and safety of Kv10.1-directed therapeutic strategies.
Collapse
|
6
|
Potier-Cartereau M, Raoul W, Weber G, Mahéo K, Rapetti-Mauss R, Gueguinou M, Buscaglia P, Goupille C, Le Goux N, Abdoul-Azize S, Lecomte T, Fromont G, Chantome A, Mignen O, Soriani O, Vandier C. Potassium and Calcium Channel Complexes as Novel Targets for Cancer Research. Rev Physiol Biochem Pharmacol 2020; 183:157-176. [PMID: 32767122 DOI: 10.1007/112_2020_24] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The intracellular Ca2+ concentration is mainly controlled by Ca2+ channels. These channels form complexes with K+ channels, which function to amplify Ca2+ flux. In cancer cells, voltage-gated/voltage-dependent Ca2+ channels and non-voltage-gated/voltage-independent Ca2+ channels have been reported to interact with K+ channels such as Ca2+-activated K+ channels and voltage-gated K+ channels. These channels are activated by an increase in cytosolic Ca2+ concentration or by membrane depolarization, which induces membrane hyperpolarization, increasing the driving force for Ca2+ flux. These complexes, composed of K+ and Ca2+ channels, are regulated by several molecules including lipids (ether lipids and cholesterol), proteins (e.g. STIM), receptors (e.g. S1R/SIGMAR1), and peptides (e.g. LL-37) and can be targeted by monoclonal antibodies, making them novel targets for cancer research.
Collapse
Affiliation(s)
| | - William Raoul
- N2C UMR 1069, University of Tours, INSERM, Tours, France
| | - Gunther Weber
- N2C UMR 1069, University of Tours, INSERM, Tours, France
| | - Karine Mahéo
- N2C UMR 1069, University of Tours, INSERM, Tours, France
| | | | | | - Paul Buscaglia
- LBAI UMR 1227, University of Brest, INSERM, Brest, France
| | - Caroline Goupille
- N2C UMR 1069, University of Tours, INSERM, CHRU de Tours, Tours, France
| | - Nelig Le Goux
- LBAI UMR 1227, University of Brest, INSERM, Brest, France
| | | | - Thierry Lecomte
- EA 7501 GICC, University of Tours, CHRU de Tours, Department of Hepato-Gastroenterology and Digestive Oncology, Tours, France
| | - Gaëlle Fromont
- N2C UMR 1069, University of Tours, INSERM, CHRU de Tours, Department of Pathology, Tours, France
| | | | - Olivier Mignen
- LBAI UMR 1227, University of Brest, INSERM, Brest, France
| | - Olivier Soriani
- iBV, INSERM, CNRS, University of the Côte d'Azur, Nice, France
| | | |
Collapse
|
7
|
Becskeházi E, Korsós MM, Erőss B, Hegyi P, Venglovecz V. OEsophageal Ion Transport Mechanisms and Significance Under Pathological Conditions. Front Physiol 2020; 11:855. [PMID: 32765303 PMCID: PMC7379034 DOI: 10.3389/fphys.2020.00855] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 06/25/2020] [Indexed: 12/20/2022] Open
Abstract
Ion transporters play an important role in several physiological functions, such as cell volume regulation, pH homeostasis and secretion. In the oesophagus, ion transport proteins are part of the epithelial resistance, a mechanism which protects the oesophagus against reflux-induced damage. A change in the function or expression of ion transporters has significance in the development or neoplastic progression of Barrett’s oesophagus (BO). In this review, we discuss the physiological and pathophysiological roles of ion transporters in the oesophagus, highlighting transport proteins which serve as therapeutic targets or prognostic markers in eosinophilic oesophagitis, BO and esophageal cancer. We believe that this review highlights important relationships which might contribute to a better understanding of the pathomechanisms of esophageal diseases.
Collapse
Affiliation(s)
- Eszter Becskeházi
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| | | | - Bálint Erőss
- Institute for Translational Medicine, Szentágothai Research Centre, Medical School, University of Pécs, Pécs, Hungary
| | - Péter Hegyi
- Institute for Translational Medicine, Szentágothai Research Centre, Medical School, University of Pécs, Pécs, Hungary.,Division of Gastroenterology, First Department of Medicine, Medical School, University of Pécs, Pécs, Hungary.,First Department of Medicine, University of Szeged, Szeged, Hungary
| | - Viktória Venglovecz
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
| |
Collapse
|
8
|
Hartung F, Krüwel T, Shi X, Pfizenmaier K, Kontermann R, Chames P, Alves F, Pardo LA. A Novel Anti-Kv10.1 Nanobody Fused to Single-Chain TRAIL Enhances Apoptosis Induction in Cancer Cells. Front Pharmacol 2020; 11:686. [PMID: 32528281 PMCID: PMC7246340 DOI: 10.3389/fphar.2020.00686] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 04/27/2020] [Indexed: 01/11/2023] Open
Abstract
Antibody-based therapies hold promise for a safe and efficient treatment of cancer. The identification of target tumor cells through a specific antigen enriched on their surface and the subsequent delivery of the therapeutic agent only to those cells requires, besides the efficacy of the therapeutic agent itself, the identification of an antigen enriched on the surface of tumor cells, the generation of high affinity antibodies against that antigen. We have generated single-domain antibodies (nanobodies) against the voltage-gated potassium channel Kv10.1, which outside of the brain is detectable almost exclusively in tumor cells. The nanobody with highest affinity was fused to an improved form of the tumor necrosis factor-related apoptosis inducing ligand TRAIL, to target this cytokine to the surface of tumor cells. The resulting construct, VHH-D9-scTRAIL, shows rapid and strong apoptosis induction in different tumor models in cell culture. The construct combines two sources of specificity, the expression of the antigen restricted to tumor cells and the tumor selectivity of TRAIL. Such specificity combined with the high affinity obtained through nanobodies make the novel agent a promising concept for cancer therapy.
Collapse
Affiliation(s)
- Franziska Hartung
- Oncophysiology Group, Max Planck, Institute of Experimental Medicine, Göttingen, Germany
| | - Thomas Krüwel
- Institute of Diagnostic and Interventional Radiology, University Medical Center Göttingen, Göttingen, Germany
| | - Xiaoyi Shi
- Oncophysiology Group, Max Planck, Institute of Experimental Medicine, Göttingen, Germany
| | - Klaus Pfizenmaier
- Institut für Zellbiologie und Immunologie, Universität Stuttgart, Stuttgart, Germany
| | - Roland Kontermann
- Institut für Zellbiologie und Immunologie, Universität Stuttgart, Stuttgart, Germany
| | - Patrick Chames
- Aix Marseille Univ, CNRS, Inserm, Institut Paoli-Calmettes, CRCM, Marseille, France
| | - Frauke Alves
- Institute of Diagnostic and Interventional Radiology, University Medical Center Göttingen, Göttingen, Germany.,Translational Molecular Imaging Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Luis A Pardo
- Oncophysiology Group, Max Planck, Institute of Experimental Medicine, Göttingen, Germany
| |
Collapse
|
9
|
Iorio J, Petroni G, Duranti C, Lastraioli E. Potassium and Sodium Channels and the Warburg Effect: Biophysical Regulation of Cancer Metabolism. Bioelectricity 2019; 1:188-200. [PMID: 34471821 PMCID: PMC8370285 DOI: 10.1089/bioe.2019.0017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Ion channels are progressively emerging as a novel class of membrane proteins expressed in several types of human cancers and regulating the different aspects of cancer cell behavior. The metabolism of cancer cells, usually composed by a variable proportion of respiration, glycolysis, and glutaminolysis, leads to the excessive production of acidic metabolic products. The presence of these acidic metabolites inside the cells results in intracellular acidosis, and hinders survival and proliferation. For this reason, tumor cells activate mechanisms of pH control that produce a constitutive increase in intracellular pH (pHi) that is more acidic than the extracellular pH (pHe). This condition forms a perfect microenvironment for metastatic progression and may be permissive for some of the acquired characteristics of tumors. Recent analyses have revealed complex interconnections between oncogenic activation, ion channels, hypoxia signaling and metabolic pathways that are dysregulated in cancer. Here, we summarize the molecular mechanisms of the Warburg effect and hypoxia and their association. Moreover, we discuss the recent findings concerning the involvement of ion channels in various aspects of the Warburg effect and hypoxia, focusing on the role of Na+ and K+ channels in hypoxic and metabolic reprogramming in cancer.
Collapse
Affiliation(s)
- Jessica Iorio
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Giulia Petroni
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Claudia Duranti
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Elena Lastraioli
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| |
Collapse
|
10
|
Moreels L, Peigneur S, Yamaguchi Y, Vriens K, Waelkens E, Zhu S, Thevissen K, Cammue BPA, Sato K, Tytgat J. Expanding the pharmacological profile of κ-hefutoxin 1 and analogues: A focus on the inhibitory effect on the oncogenic channel K v10.1. Peptides 2017; 98:43-50. [PMID: 27578329 DOI: 10.1016/j.peptides.2016.08.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 08/21/2016] [Accepted: 08/23/2016] [Indexed: 10/21/2022]
Abstract
Peptide toxins, such as scorpion peptides, are interesting lead compounds in the search for novel drugs. In this paper, the focus is on the scorpion peptide κ-hefutoxin 1. This peptide displays a cysteine-stabilized helix-loop-helix fold (CSα/α) and is known to be a weak Kv1.x inhibitor. Due to the low affinity of κ-hefutoxin 1 for these channels, it is assumed that the main target(s) of κ-hefutoxin 1 remain(s) unknown. In order to identify novel targets, electrophysiological measurements and antifungal assays were performed. The effect of κ-hefutoxin 1 was previously evaluated on a panel of 11 different voltage-gated potassium channels. Here, we extended this target screening with the oncogenic potassium channel Kv10.1. κ-Hefutoxin 1 was able to inhibit this channel in a dose-dependent manner (IC50∼26μM). Although the affinity is rather low, this is the first peptide toxin ever described to be a Kv10.1 inhibitor. The structure-activity relationship of κ-hefutoxin 1 on Kv10.1 was investigated by testing eight κ-hefutoxin 1 variants using the two-electrode voltage clamp technique. Several important amino acid residues were identified; the functional dyad residues (Tyr5 and Lys19), N-terminal residues (Gly1 and His2) and the amidated C-terminal residue (Cys22). Since the CSα/α fold is also found in a class of antifungal plant peptides, the α-hairpinines, we investigated the antifungal activity of κ-hefutoxin 1. κ-Hefutoxin 1 showed low activity against the plant pathogen Fusarium culmorum and no activity against three other yeast and fungal species, even at high concentrations (∼100μM).
Collapse
Affiliation(s)
- Lien Moreels
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
| | - Steve Peigneur
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
| | - Yoko Yamaguchi
- Department of Environmental Science, Fukuoka Women's University, Fukuoka 813-8529, Japan.
| | - Kim Vriens
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium.
| | - Etienne Waelkens
- Laboratory of Protein Phosphorylation and Proteomics, KU Leuven, Campus Gasthuisberg, O&N1, Herestraat 49, PO Box 901, 3000 Leuven, Belgium.
| | - Shunyi Zhu
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium.
| | - Bruno P A Cammue
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, PO Box 2460, 3001 Leuven, Belgium; VIB Department of Plant Systems Biology, Technologiepark 927, 9052 Ghent, Belgium.
| | - Kazuki Sato
- Department of Environmental Science, Fukuoka Women's University, Fukuoka 813-8529, Japan.
| | - Jan Tytgat
- Toxicology and Pharmacology, KU Leuven, Campus Gasthuisberg O&N2, Herestraat 49, PO Box 922, 3000 Leuven, Belgium.
| |
Collapse
|
11
|
Moreels L, Peigneur S, Galan DT, De Pauw E, Béress L, Waelkens E, Pardo LA, Quinton L, Tytgat J. APETx4, a Novel Sea Anemone Toxin and a Modulator of the Cancer-Relevant Potassium Channel K V10.1. Mar Drugs 2017; 15:md15090287. [PMID: 28902151 PMCID: PMC5618426 DOI: 10.3390/md15090287] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 09/05/2017] [Accepted: 09/07/2017] [Indexed: 12/31/2022] Open
Abstract
The human ether-à-go-go channel (hEag1 or KV10.1) is a cancer-relevant voltage-gated potassium channel that is overexpressed in a majority of human tumors. Peptides that are able to selectively inhibit this channel can be lead compounds in the search for new anticancer drugs. Here, we report the activity-guided purification and electrophysiological characterization of a novel KV10.1 inhibitor from the sea anemone Anthopleura elegantissima. Purified sea anemone fractions were screened for inhibitory activity on KV10.1 by measuring whole-cell currents as expressed in Xenopus laevis oocytes using the two-microelectrode voltage clamp technique. Fractions that showed activity on Kv10.1 were further purified by RP-HPLC. The amino acid sequence of the peptide was determined by a combination of MALDI- LIFT-TOF/TOF MS/MS and CID-ESI-FT-ICR MS/MS and showed a high similarity with APETx1 and APETx3 and was therefore named APETx4. Subsequently, the peptide was electrophysiologically characterized on KV10.1. The selectivity of the toxin was investigated on an array of voltage-gated ion channels, including the cardiac human ether-à-go-go-related gene potassium channel (hERG or Kv11.1). The toxin inhibits KV10.1 with an IC50 value of 1.1 μM. In the presence of a similar toxin concentration, a shift of the activation curve towards more positive potentials was observed. Similar to the effect of the gating modifier toxin APETx1 on hERG, the inhibition of Kv10.1 by the isolated toxin is reduced at more positive voltages and the peptide seems to keep the channel in a closed state. Although the peptide also induces inhibitory effects on other KV and NaV channels, it exhibits no significant effect on hERG. Moreover, APETx4 induces a concentration-dependent cytotoxic and proapoptotic effect in various cancerous and noncancerous cell lines. This newly identified KV10.1 inhibitor can be used as a tool to further characterize the oncogenic channel KV10.1 or as a scaffold for the design and synthesis of more potent and safer anticancer drugs.
Collapse
Affiliation(s)
- Lien Moreels
- Toxicology and Pharmacology, KU Leuven, Leuven 3000, Belgium.
| | - Steve Peigneur
- Toxicology and Pharmacology, KU Leuven, Leuven 3000, Belgium.
| | - Diogo T Galan
- Toxicology and Pharmacology, KU Leuven, Leuven 3000, Belgium.
| | - Edwin De Pauw
- Laboratory of Mass Spectrometry-MolSys, University of Liege, Liege 4000, Belgium.
| | - Lászlo Béress
- Immunology and Rheumatology, Section of Peptide Chemistry, Hannover Medical School (MHH), Hannover 30625, Germany.
| | - Etienne Waelkens
- Laboratory of Protein Phosphorylation and Proteomics, KU Leuven, Leuven 3000, Belgium.
| | - Luis A Pardo
- Oncophysiology Group, Max Planck Institute for Experimental Medicine; Göttingen 37075, Germany.
| | - Loïc Quinton
- Laboratory of Mass Spectrometry-MolSys, University of Liege, Liege 4000, Belgium.
| | - Jan Tytgat
- Toxicology and Pharmacology, KU Leuven, Leuven 3000, Belgium.
| |
Collapse
|
12
|
Urrego D, Movsisyan N, Ufartes R, Pardo LA. Periodic expression of Kv10.1 driven by pRb/E2F1 contributes to G2/M progression of cancer and non-transformed cells. Cell Cycle 2016; 15:799-811. [PMID: 27029528 PMCID: PMC4845928 DOI: 10.1080/15384101.2016.1138187] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Progression of cell cycle is associated with changes in K+ channel expression and activity. In this study, we report that Kv10.1, a K+ channel that increases cell proliferation and tumor growth, is regulated at the transcriptional level by the pRb/E2F1 pathway. De-repression of E2F1 by HPV-E7 oncoprotein leads to increased expression of Kv10.1. In proliferating cells, E2F1 transcription factor binds directly to the Kv10.1 promoter during (or close to) G2/M, resulting in transient expression of the channel. Importantly, this happens not only in cancer cells but also in non-transformed cells. Lack of Kv10.1 in both cancer and non-transformed cells resulted in prolonged G2/M phase, as indicated by phosphorylation of Cdk1 (Y15) and sustained pRb hyperphosphorylation. Our results strongly suggest that Kv10.1 expression is coupled to cell cycle progression and facilitates G2/M progression in both healthy and tumor cells.
Collapse
Affiliation(s)
- Diana Urrego
- a Oncophysiology Group, Max-Planck-Institute of Experimental Medicine , Göttingen , Germany
| | - Naira Movsisyan
- a Oncophysiology Group, Max-Planck-Institute of Experimental Medicine , Göttingen , Germany
| | - Roser Ufartes
- b Department of Molecular Biology of Neuronal Signals , Max-Planck-Institute of Experimental Medicine , Göttingen , Germany
| | - Luis A Pardo
- a Oncophysiology Group, Max-Planck-Institute of Experimental Medicine , Göttingen , Germany
| |
Collapse
|
13
|
Kv10.1 K+ channel: from physiology to cancer. Pflugers Arch 2016; 468:751-62. [DOI: 10.1007/s00424-015-1784-3] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/11/2015] [Accepted: 12/27/2015] [Indexed: 12/18/2022]
|
14
|
Martínez R, Stühmer W, Martin S, Schell J, Reichmann A, Rohde V, Pardo L. Analysis of the expression of Kv10.1 potassium channel in patients with brain metastases and glioblastoma multiforme: impact on survival. BMC Cancer 2015; 15:839. [PMID: 26530050 PMCID: PMC4632660 DOI: 10.1186/s12885-015-1848-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/26/2015] [Indexed: 01/01/2023] Open
Abstract
Background Kv10.1, a voltage-gated potassium channel only detected in the healthy brain, was found to be aberrantly expressed in extracerebral cancers. Investigations of Kv10.1 in brain metastasis and glioblastoma multiforme (GBM) are lacking. Methods We analyzed the expression of Kv10.1 by immunohistochemistry in these brain tumors (75 metastasis from different primary tumors, 71 GBM patients) and the influence of a therapy with tricyclic antidepressants (which are Kv10.1 blockers) on survival. We also investigated Kv10.1 expression in the corresponding primary carcinomas of metastases patients. Results We observed positive Kv10.1 expression in 85.3 % of the brain metastases and in 77.5 % of GBMs. Patients with brain metastases, showing low Kv10.1 expression, had a significantly longer overall survival compared to those patients with high Kv10.1 expression. Metastases patients displaying low Kv10.1 expression and also receiving tricyclic antidepressants showed a significantly longer median overall survival as compared to untreated patients. Conclusions Our data show that Kv10.1 is not only highly expressed in malignant tumors outside CNS, but also in the most frequent cerebral cancer entities, metastasis and GBM, which remain incurable in spite of aggressive multimodal therapies. Our results extend the correlation between dismal prognosis and Kv10.1 expression to patients with brain metastases or GBMs and, moreover, they strongly suggest a role of tricyclic antidepressants for personalized therapy of brain malignancies.
Collapse
Affiliation(s)
- Ramón Martínez
- Department of Neurosurgery, University of Goettingen, Robert-Koch-Str. 40, Goettingen, 37075, Germany.
| | - Walter Stühmer
- Department of Molecular Biology of Neuronal Signals, Max-Planck Institute for Experimental Medicine, Hermann-Rein-Str. 3, Goettingen, 37075, Germany.
| | - Sabine Martin
- Department of Molecular Biology of Neuronal Signals, Max-Planck Institute for Experimental Medicine, Hermann-Rein-Str. 3, Goettingen, 37075, Germany.
| | - Julian Schell
- Department of Neurosurgery, University of Goettingen, Robert-Koch-Str. 40, Goettingen, 37075, Germany.
| | - Andrea Reichmann
- Department of Neurosurgery, University of Goettingen, Robert-Koch-Str. 40, Goettingen, 37075, Germany.
| | - Veit Rohde
- Department of Neurosurgery, University of Goettingen, Robert-Koch-Str. 40, Goettingen, 37075, Germany.
| | - Luis Pardo
- Department of Molecular Biology of Neuronal Signals, Max-Planck Institute for Experimental Medicine, Hermann-Rein-Str. 3, Goettingen, 37075, Germany.
| |
Collapse
|
15
|
Ion channel expression as promising cancer biomarker. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:2685-702. [PMID: 25542783 DOI: 10.1016/j.bbamem.2014.12.016] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/10/2014] [Accepted: 12/16/2014] [Indexed: 12/11/2022]
Abstract
Cancer is a disease with marked heterogeneity in both response to therapy and survival. Clinical and histopathological characteristics have long determined prognosis and therapy. The introduction of molecular diagnostics has heralded an explosion in new prognostic factors. Overall, histopathology, immunohistochemistry and molecular biology techniques have described important new prognostic subgroups in the different cancer categories. Ion channels and transporters (ICT) are a new class of membrane proteins which are aberrantly expressed in several types of human cancers. Besides regulating different aspect of cancer cell behavior, ICT can now represent novel cancer biomarkers. A summary of the data obtained so far and relative to breast, prostate, lung, colorectal, esophagus, pancreatic and gastric cancers are reported. Special emphasis is given to those studies aimed at relating specific ICT or a peculiar ICT profile with current diagnostic methods. Overall, we are close to exploit ICTs for diagnostic, prognostic or predictive purposes in cancer. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.
Collapse
|
16
|
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.
Collapse
|
17
|
Lai Q, Wang T, Guo Q, Zhang Y, Wang Y, Yuan L, Ling R, He Y, Wang W. Positive correlation between the expression of hEag1 and HIF-1α in breast cancers: an observational study. BMJ Open 2014; 4:e005049. [PMID: 24838727 PMCID: PMC4025446 DOI: 10.1136/bmjopen-2014-005049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVES To explore the expression patterns of Eag1 (ether á go-go 1) and HIF-1α (hypoxia-inducible factor 1α) in a cohort of patients with breast cancer. SETTING Department of general surgery in an upper first-class hospital in Xi'an, China. PARTICIPANTS A total of 112 female Han Chinese patients with a diagnosis of invasive ductal carcinoma were included. Patients with main internal diseases, such as cardiovascular, endocrine, gastroenterological, haematological, infectious diseases, etc, were excluded. PRIMARY AND SECONDARY OUTCOME MEASURES Expression profiles of Eag1 and HIF-1α. RESULTS Eag1 and HIF-1α were overexpressed in the tumour tissues compared with the pair-matched control tissues, p=0.002 and <0.001, respectively. The expression of Eag1 and HIF-1α was negatively correlated with tumour size, p=0.032 and p=0.025, respectively, and lymph node status (p=0.040, p=0.032, respectively). The coexpression of Eag1 and HIF-1α was correlated with tumour size (p=0.012), lymph node status (p=0.027) and tumour stage (p=0.036). HIF-1α has a strong correlation with hEag1 expression (κ=0.731, p<0.001). CONCLUSIONS HIF-1α expression has a strong correlation with hEag1 expression. We are the first to attempt to explore the correlation at the population level.
Collapse
Affiliation(s)
- Qingxuan Lai
- College of Life Science, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Ting Wang
- Department of General Surgery, Xijing Hospital, Xi'an, People's Republic of China
| | - Qingqing Guo
- Beijing Municipal Key Laboratory of Clinical Epidemiology, School of Public Health, Capital Medical University, Beijing, People's Republic of China
| | - Yuxiang Zhang
- Beijing Municipal Key Laboratory of Clinical Epidemiology, School of Public Health, Capital Medical University, Beijing, People's Republic of China
| | - Youxin Wang
- Beijing Municipal Key Laboratory of Clinical Epidemiology, School of Public Health, Capital Medical University, Beijing, People's Republic of China
| | - Li Yuan
- College of Life Science, University of Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Rui Ling
- Department of General Surgery, Xijing Hospital, Xi'an, People's Republic of China
| | - Yan He
- Beijing Municipal Key Laboratory of Clinical Epidemiology, School of Public Health, Capital Medical University, Beijing, People's Republic of China
| | - Wei Wang
- Beijing Municipal Key Laboratory of Clinical Epidemiology, School of Public Health, Capital Medical University, Beijing, People's Republic of China School of Medical Sciences, Edith Cowan University, Perth, Australia
| |
Collapse
|
18
|
Abstract
Ion channels and transporters are expressed in every living cell, where they participate in controlling a plethora of biological processes and physiological functions, such as excitation of cells in response to stimulation, electrical activities of cells, excitation-contraction coupling, cellular osmolarity, and even cell growth and death. Alterations of ion channels/transporters can have profound impacts on the cellular physiology associated with these proteins. Expression of ion channels/transporters is tightly regulated and expression deregulation can trigger abnormal processes, leading to pathogenesis, the channelopathies. While transcription factors play a critical role in controlling the transcriptome of ion channels/transporters at the transcriptional level by acting on the 5'-flanking region of the genes, microribonucleic acids (miRNAs), a newly discovered class of regulators in the gene network, are also crucial for expression regulation at the posttranscriptional level through binding to the 3'untranslated region of the genes. These small noncoding RNAs fine tune expression of genes involved in a wide variety of cellular processes. Recent studies revealed the role of miRNAs in regulating expression of ion channels/transporters and the associated physiological functions. miRNAs can target ion channel genes to alter cardiac excitability (conduction, repolarization, and automaticity) and affect arrhythmogenic potential of heart. They can modulate circadian rhythm, pain threshold, neuroadaptation to alcohol, brain edema, etc., through targeting ion channel genes in the neuronal systems. miRNAs can also control cell growth and tumorigenesis by acting on the relevant ion channel genes. Future studies are expected to rapidly increase to unravel a new repertoire of ion channels/transporters for miRNA regulation.
Collapse
Affiliation(s)
- Zhiguo Wang
- Harbin Medical University, Harbin, Heilongjiang, People's Republic of China.
| |
Collapse
|
19
|
Williams S, Bateman A, O'Kelly I. Altered expression of two-pore domain potassium (K2P) channels in cancer. PLoS One 2013; 8:e74589. [PMID: 24116006 PMCID: PMC3792113 DOI: 10.1371/journal.pone.0074589] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/03/2013] [Indexed: 01/31/2023] Open
Abstract
Potassium channels have become a focus in cancer biology as they play roles in cell behaviours associated with cancer progression, including proliferation, migration and apoptosis. Two-pore domain (K2P) potassium channels are background channels which enable the leak of potassium ions from cells. As these channels are open at rest they have a profound effect on cellular membrane potential and subsequently the electrical activity and behaviour of cells in which they are expressed. The K2P family of channels has 15 mammalian members and already 4 members of this family (K2P2.1, K2P3.1, K2P9.1, K2P5.1) have been implicated in cancer. Here we examine the expression of all 15 members of the K2P family of channels in a range of cancer types. This was achieved using the online cancer microarray database, Oncomine (www.oncomine.org). Each gene was examined across 20 cancer types, comparing mRNA expression in cancer to normal tissue. This analysis revealed all but 3 K2P family members (K2P4.1, K2P16.1, K2P18.1) show altered expression in cancer. Overexpression of K2P channels was observed in a range of cancers including breast, leukaemia and lung while more cancers (brain, colorectal, gastrointestinal, kidney, lung, melanoma, oesophageal) showed underexpression of one or more channels. K2P1.1, K2P3.1, K2P12.1, were overexpressed in a range of cancers. While K2P1.1, K2P3.1, K2P5.1, K2P6.1, K2P7.1 and K2P10.1 showed significant underexpression across the cancer types examined. This analysis supports the view that specific K2P channels may play a role in cancer biology. Their altered expression together with their ability to impact the function of other ion channels and their sensitivity to environmental stimuli (pO2, pH, glucose, stretch) makes understanding the role these channels play in cancer of key importance.
Collapse
Affiliation(s)
- Sarah Williams
- Human Development and Health, Centre for Human Development, Stem Cells and Regeneration, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Andrew Bateman
- Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Ita O'Kelly
- Human Development and Health, Centre for Human Development, Stem Cells and Regeneration, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- * E-mail: I.M.O'
| |
Collapse
|
20
|
Herrmann S, Ninkovic M, Kohl T, Pardo LA. PIST (GOPC) modulates the oncogenic voltage-gated potassium channel KV10.1. Front Physiol 2013; 4:201. [PMID: 23966943 PMCID: PMC3743135 DOI: 10.3389/fphys.2013.00201] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 07/17/2013] [Indexed: 11/13/2022] Open
Abstract
Although crucial for their correct function, the mechanisms controlling surface expression of ion channels are poorly understood. In the case of the voltage-gated potassium channel KV10.1, this is determinant not only for its physiological function in brain, but also for its pathophysiology in tumors and possible use as a therapeutic target. The Golgi resident protein PIST binds several membrane proteins, thereby modulating their expression. Here we describe a PDZ domain-mediated interaction of KV10.1 and PIST, which enhances surface levels of KV10.1. The functional, but not the physical interaction of both proteins is dependent on the coiled-coil and PDZ domains of PIST; insertion of eight amino acids in the coiled-coil domain to render the neural form of PIST (nPIST) and the corresponding short isoform in an as-of-yet unknown form abolishes the effect. In addition, two new isoforms of PIST (sPIST and nsPIST) lacking nearly the complete PDZ domain were cloned and shown to be ubiquitously expressed. PIST and KV10.1 co-precipitate from native and expression systems. nPIST also showed interaction, but did not alter the functional expression of the channel. We could not document physical interaction between KV10.1 and sPIST, but it reduced KV10.1 functional expression in a dominant-negative manner. nsPIST showed weak physical interaction and no functional effect on KV10.1. We propose these isoforms to work as modulators of PIST function via regulating the binding on interaction partners.
Collapse
Affiliation(s)
- Solveig Herrmann
- AG Oncophysiology, Max-Planck Institute of Experimental Medicine Göttingen, Germany
| | | | | | | |
Collapse
|
21
|
Ufartes R, Schneider T, Mortensen LS, de Juan Romero C, Hentrich K, Knoetgen H, Beilinson V, Moebius W, Tarabykin V, Alves F, Pardo LA, Rawlins JNP, Stuehmer W. Behavioural and functional characterization of Kv10.1 (Eag1) knockout mice. Hum Mol Genet 2013; 22:2247-62. [PMID: 23424202 PMCID: PMC3652421 DOI: 10.1093/hmg/ddt076] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Kv10.1 (Eag1), member of the Kv10 family of voltage-gated potassium channels, is preferentially expressed in adult brain. The aim of the present study was to unravel the functional role of Kv10.1 in the brain by generating knockout mice, where the voltage sensor and pore region of Kv10.1 were removed to render non-functional proteins through deletion of exon 7 of the KCNH1 gene using the ‘3 Lox P strategy’. Kv10.1-deficient mice show no obvious alterations during embryogenesis and develop normally to adulthood; cortex, hippocampus and cerebellum appear anatomically normal. Other tests, including general health screen, sensorimotor functioning and gating, anxiety, social behaviour, learning and memory did not show any functional aberrations in Kv10.1 null mice. Kv10.1 null mice display mild hyperactivity and longer-lasting haloperidol-induced catalepsy, but there was no difference between genotypes in amphetamine sensitization and withdrawal, reactivity to apomorphine and haloperidol in the prepulse inhibition tests or to antidepressants in the haloperidol-induced catalepsy. Furthermore, electrical properties of Kv10.1 in cerebellar Purkinje cells did not show any difference between genotypes. Bearing in mind that Kv10.1 is overexpressed in over 70% of all human tumours and that its inhibition leads to a reduced tumour cell proliferation, the fact that deletion of Kv10.1 does not show a marked phenotype is a prerequisite for utilizing Kv10.1 blocking and/or reduction techniques, such as siRNA, to treat cancer.
Collapse
Affiliation(s)
- Roser Ufartes
- Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute for Experimental Medicine, Hermann-Rein-Str. 3, Göttingen 37077, Germany.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
22
|
MiR-296-3p regulates cell growth and multi-drug resistance of human glioblastoma by targeting ether-à-go-go (EAG1). Eur J Cancer 2012; 49:710-24. [PMID: 22999387 DOI: 10.1016/j.ejca.2012.08.020] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 05/30/2012] [Accepted: 08/22/2012] [Indexed: 01/03/2023]
Abstract
MicroRNAs (miRNAs) - short non-coding RNA molecules - post-transcriptionally regulate gene expressions and play crucial roles in diverse biological processes such as development, differentiation, apoptosis and proliferation. In order to investigate the possible role of miRNAs in the development of multi-drug resistance (MDR) in human glioblastoma, we first detected (by Western blotting, real-time polymerase chain reaction [RT-PCR] and immunohistochemistry) the expression of miR-296-3p and ether-à-go-go (EAG1 or KCNH1) in U251 cells, U251/imatinib mesylate (U251AR cells) and clinical specimens. The results showed that miR-296-3p was down-regulated in U251AR cells, concurrent with the up-regulation of EAG1 protein, compared with the parental U251 cell line. In vitro drug sensitivity assay demonstrated that over-expression of miR-296-3p sensitised glioblastoma (GBM) cells to anticancer drugs, whereas down-expression using antisense oligonucleotides conferred MDR. Ectopic expression of miR-296-3p reduced EAG1 expression and suppressed cell proliferation drug resistance, and the luciferase activity of an EAG1 3'-untranslated region-based reporter construct in U251AR cells, whereas EAG1 over-expression rescued the suppressive effect of miR-296-3p in U251AR cells. We also found that EAG1 was widely over-expressed and inversely correlated with miR-296-3p in clinical specimens. Taken together, our findings suggest that miR-296-3p may play a role of MDR in glioblastoma at least in part by targeting EAG1.
Collapse
|
23
|
Abstract
Ion channels are involved in a variety of tumors. In particular, potassium channels are expressed abnormally in many cancer types, where their pharmacologic manipulation impairs tumor progression. Since this group of molecules has been successfully targeted for decades in other therapeutic areas, there is a significant body of knowledge on the pharmacology of potassium channels. Several groups of potassium channels with defined molecular identities have been proposed as candidates for therapeutic intervention. The strategies put forward range from classical small molecule blockade to gene therapy approaches, and include the use of potassium channels as targets for adjuvant therapy. We will discuss the reasons for these proposals and explore possible future developments.
Collapse
|
24
|
Lin H, Li Z, Chen C, Luo X, Xiao J, Dong D, Lu Y, Yang B, Wang Z. Transcriptional and post-transcriptional mechanisms for oncogenic overexpression of ether à go-go K+ channel. PLoS One 2011; 6:e20362. [PMID: 21655246 PMCID: PMC3105031 DOI: 10.1371/journal.pone.0020362] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Accepted: 04/30/2011] [Indexed: 11/23/2022] Open
Abstract
The human ether-à-go-go-1 (h-eag1) K+ channel is expressed in a variety of cell lines derived from human malignant tumors and in clinical samples of several different cancers, but is otherwise absent in normal tissues. It was found to be necessary for cell cycle progression and tumorigenesis. Specific inhibition of h-eag1 expression leads to inhibition of tumor cell proliferation. We report here that h-eag1 expression is controlled by the p53−miR-34−E2F1 pathway through a negative feed-forward mechanism. We first established E2F1 as a transactivator of h-eag1 gene through characterizing its promoter region. We then revealed that miR-34, a known transcriptional target of p53, is an important negative regulator of h-eag1 through dual mechanisms by directly repressing h-eag1 at the post-transcriptional level and indirectly silencing h-eag1 at the transcriptional level via repressing E2F1. There is a strong inverse relationship between the expression levels of miR-34 and h-eag1 protein. H-eag1antisense antagonized the growth-stimulating effects and the upregulation of h-eag1 expression in SHSY5Y cells, induced by knockdown of miR-34, E2F1 overexpression, or inhibition of p53 activity. Therefore, p53 negatively regulates h-eag1 expression by a negative feed-forward mechanism through the p53−miR-34−E2F1 pathway. Inactivation of p53 activity, as is the case in many cancers, can thus cause oncogenic overexpression of h-eag1 by relieving the negative feed-forward regulation. These findings not only help us understand the molecular mechanisms for oncogenic overexpression of h-eag1 in tumorigenesis but also uncover the cell-cycle regulation through the p53−miR-34−E2F1−h-eag1 pathway. Moreover, these findings place h-eag1 in the p53−miR-34−E2F1−h-eag1 pathway with h-eag as a terminal effecter component and with miR-34 (and E2F1) as a linker between p53 and h-eag1. Our study therefore fills the gap between p53 pathway and its cellular function mediated by h-eag1.
Collapse
Affiliation(s)
- Huixian Lin
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
| | - Zhe Li
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
| | - Chang Chen
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
| | - Xiaobin Luo
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
- Department of Medicine, Universite de Montreal, Montreal, Quebec, Canada
- Cardiovascular Research Institute (Key Laboratory of Cardiovascular Research, Ministry of Education of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
| | - Jiening Xiao
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
| | - Deli Dong
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
| | - Yanjie Lu
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
- Cardiovascular Research Institute (Key Laboratory of Cardiovascular Research, Ministry of Education of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
| | - Baofeng Yang
- Department of Pharmacology (State-Province Key Laboratories of Biomedicine-Pharmaceutics of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
- Cardiovascular Research Institute (Key Laboratory of Cardiovascular Research, Ministry of Education of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
- * E-mail: (ZW); (BY)
| | - Zhiguo Wang
- Research Center, Montreal Heart Institute, Montreal, Quebec, Canada
- Department of Medicine, Universite de Montreal, Montreal, Quebec, Canada
- Cardiovascular Research Institute (Key Laboratory of Cardiovascular Research, Ministry of Education of China), Harbin Medical University, Harbin, Heilongjiang, People's Republic of China
- * E-mail: (ZW); (BY)
| |
Collapse
|
25
|
Chen Y, Sánchez A, Rubio ME, Kohl T, Pardo LA, Stühmer W. Functional K(v)10.1 channels localize to the inner nuclear membrane. PLoS One 2011; 6:e19257. [PMID: 21559285 PMCID: PMC3086910 DOI: 10.1371/journal.pone.0019257] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 03/31/2011] [Indexed: 01/09/2023] Open
Abstract
Ectopically expressed human KV10.1 channels are relevant players in tumor biology. However, their function as ion channels at the plasma membrane does not totally explain their crucial role in tumors. Both in native and heterologous systems, it has been observed that a majority of KV10.1 channels remain at intracellular locations. In this study we investigated the localization and possible roles of perinuclear KV10.1. We show that KV10.1 is expressed at the inner nuclear membrane in both human and rat models; it co-purifies with established inner nuclear membrane markers, shows resistance to detergent extraction and restricted mobility, all of them typical features of proteins at the inner nuclear membrane. KV10.1 channels at the inner nuclear membrane are not all transported directly from the ER but rather have been exposed to the extracellular milieu. Patch clamp experiments on nuclei devoid of external nuclear membrane reveal the existence of channel activity compatible with KV10.1. We hypothesize that KV10.1 channels at the nuclear envelope might participate in the homeostasis of nuclear K+, or indirectly interact with heterochromatin, both factors known to affect gene expression.
Collapse
Affiliation(s)
- Ye Chen
- Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Araceli Sánchez
- Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - María E. Rubio
- Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut, United States of America
| | - Tobias Kohl
- Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Luis A. Pardo
- Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
- * E-mail: (LAP); (WS)
| | - Walter Stühmer
- Department of Molecular Biology of Neuronal Signals, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
- * E-mail: (LAP); (WS)
| |
Collapse
|
26
|
Ding X, He Z, Shi Y, Wang Q, Wang Y. Targeting TRPC6 channels in oesophageal carcinoma growth. Expert Opin Ther Targets 2010; 14:513-27. [DOI: 10.1517/14728221003733602] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
27
|
Ding XW, Gao S, Wang W, Yan JJ, Luo HS. Effect of imipramine on HT-29 cells' proliferation, cell cycle arrest and apoptosis and its mechanism. Shijie Huaren Xiaohua Zazhi 2008; 16:3043-3049. [DOI: 10.11569/wcjd.v16.i27.3043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of imipramine on cell growth, cell cycle and apoptosis of HT-29 colon cancer cells, and to elucidate its molecular mechanism.
METHODS: Human colon cancer HT-29 cells were grown with routine cell cultivation and cells were treated with different concentrations of imiprmine. Cell survival was determined using MTT assay at 24 h, 48 h and 72 h, respectively; cell cycle distribution was assessed by FACS flow cytometery after propidium iodide staining; apoptosis of HT-29 cells was detected using Annexin V/PI methods and DNA ladder assay. Expression level of Eag1 protein was detected by Western blot, and mRNA expressions of p21, p27, CyclinE1 and CDK2 were determined by reverse transcription-polymerase chain reaction.
RESULTS: After treatment with imipramine in HT-29 cells at 24, 48 and 72 h, IC50 were 43, 32 and 22 μmol/L, respectively. Cell viability decreased dose-dependently and time-dependently after treatment with imiprmince in HT 29 cells. Cell cycle arrested during the G0/G1 phase accompanied by the induction of apoptosis in a dose-dependent manner. With imipramine increasing, HT-29 cells apoptosis index gradually increased (P < 0.01). Expression level of Eag1 protein was decreased in a dose-dependent manner (P < 0.05). The p21 mRNA and p27 mRNA were up-regulated (P < 0.05), and CDK2 mRNA and CyclinE1 mRNA were suppressed in imipramine-treated HT-29 cells in a dose-dependent manner (P < 0.05).
CONCLUSION: Imipramine, a non-specific inhibitor of Eag1 potassium channel, induces cell growth inhibition, cell-cycle arrest and apoptosis in HT-29 cells through up-regulation of p27 and/or p21.
Collapse
|