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Jin T, Hu B, Chen S, Wang Q, Dong X, Zhang Y, Zhu Y, Zhang Z. An in Vitro Assay of hERG K + Channel Potency for a New EGFR Inhibitor FHND004. Front Pharmacol 2018; 9:577. [PMID: 29904349 PMCID: PMC5990611 DOI: 10.3389/fphar.2018.00577] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2017] [Accepted: 05/14/2018] [Indexed: 01/01/2023] Open
Abstract
FHND004 is a newly synthesized epidermal growth factor receptor (EGFR) inhibitor for the treatment of non-small cell lung cancer (NSCLC). The aim of the present study was to investigate the impacts of FHND004 on human ether-à-go-go-related gene (hERG) K+ channels and the molecular mechanisms underlying of its action. Whole-cell patch clamp recording was performed on wild type (WT), mutant hERG channels heterologously expressed in human embryonic kidney (HEK) 293 cells or IKr endogenously expressed in HL-1 cells, respectively. FHND004 inhibited hERG K+ currents in a concentration-dependent manner with IC50 values of 8.46 ± 0.33 μM in HEK293 cells and 7.52 ± 1.27 μM in HL-1 cells, respectively. However, the inhibitory potency of FHND004 on hERG channels was significantly less than its precursor AZD9291. FHND004-induced inhibition was state-dependent with a preference within open state, but did not alter other kinetics including activation, inactivation, and recovery from inactivation or deactivation. In addition, FHND004 exhibited more potent inhibitory effects on WT/A422T and WT/H562P-hERG, two known long QT syndrome (LQTS) associated KCNH2 mutations, than WT alone. Mutations of the residues at pore regions (F656C, Y652A, S624A, and F557L) in hERG channels attenuated block effects of FHND004. Taken together, our results demonstrate the evidence that FHND004 is a less potent hERG blocker than its precursor AZD9291. There is, however, a need for caution in the potential use of FHND004 for treating NSCLC patients, especially in those with other concurrent triggering factors.
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Affiliation(s)
- Tao Jin
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China.,State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences and Institutes of Brain Science, and the Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Bingxue Hu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Shanshan Chen
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China.,Jiangsu Chia Tai Fenghai Pharmaceutical Co., Ltd., Nanjing, China
| | - Qiang Wang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Xue Dong
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Yin Zhang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Yongqiang Zhu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
| | - Zhao Zhang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing, China
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Xu T, Du XW, Hu JB, Zhu YF, Wu HL, Dai GP, Shu YM, Ouyang J. Anticancer effect of miR-96 inhibitor in bladder cancer cell lines. Oncol Lett 2018; 15:3814-3819. [PMID: 29467898 DOI: 10.3892/ol.2018.7745] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 10/03/2017] [Indexed: 12/12/2022] Open
Abstract
The present study aimed to investigate the role of microRNA-96 (miR-96) in the proliferation, invasion and apoptosis of bladder cancer cell lines, and the associated mechanisms. The expression of miR-96 and human ether-à-go-go-related (HERG1) potassium channel in the normal uroepithelium SV-HUC-1 cell line, and bladder cancer T24 and 5637 cell lines were examined using reverse transcription-polymerase chain reaction or/and western blotting. Transfection with miR-96 inhibitor or scrambled control (SC) was used to study the biological activities of miR-96 in bladder cancer cell lines. MTT, flow cytometric and Transwell assays were applied to detect cell viability, apoptosis and invasion, respectively. A dual-luciferase reporter assay was applied to determine the association between miR-96 and HERG1 expression. As demonstrated, miR-96 was highly expressed in the two bladder cancer cell lines, particularly in T24 cells. Following transfection with miR-96 inhibitor, miR-96 expression was significantly reduced in the T24 cell line, compared with SC. The miR-96 inhibitor suppressed cell proliferation and invasion, promoted apoptosis and arrested the cell cycle at the G1 phase. Consistently, HERG1 was also highly expressed in the two bladder cancer cell lines at the mRNA and protein level, but not in the normal uroepithelium cell line. The miR-96 inhibitor also significantly decreased HERG1 expression compared with SC. The results of the dual-luciferase reporter assay indicated that miR-96 directly targeted wild-type HERG1. In conclusion, miR-96 inhibitor exhibited anticancer effects on bladder cancer cells by inhibiting proliferation and invasion of cells, and promoting their apoptosis. HERG1 was an important target of miR-96. These results provided experimental evidence supporting miR-96 as a therapeutic target for patients with bladder cancer.
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Affiliation(s)
- Ting Xu
- Department of Urology, Jinhua People's Hospital, Jinhua, Zhejiang 321000, P.R. China.,Department of Urology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Xiao-Wen Du
- Department of Urology, Jinhua People's Hospital, Jinhua, Zhejiang 321000, P.R. China
| | - Jun-Biao Hu
- Department of Urology, Jinhua People's Hospital, Jinhua, Zhejiang 321000, P.R. China
| | - Yong-Feng Zhu
- Department of Urology, Jinhua People's Hospital, Jinhua, Zhejiang 321000, P.R. China
| | - Hui-Ling Wu
- Department of Urology, Jinhua People's Hospital, Jinhua, Zhejiang 321000, P.R. China
| | - Guo-Ping Dai
- Department of Urology, Jinhua People's Hospital, Jinhua, Zhejiang 321000, P.R. China
| | - Yao-Min Shu
- Department of Urology, Jinhua People's Hospital, Jinhua, Zhejiang 321000, P.R. China
| | - Jun Ouyang
- Department of Urology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
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LI GUOLIANG, SHI RUI, WU JINE, HAN WENQI, ZHANG AIFENG, CHENG GONG, XUE XIAOLIN, SUN CHAOFENG. Association of the hERG mutation with long-QT syndrome type 2, syncope and epilepsy. Mol Med Rep 2016; 13:2467-75. [PMID: 26847485 PMCID: PMC4768985 DOI: 10.3892/mmr.2016.4859] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Accepted: 08/04/2015] [Indexed: 01/08/2023] Open
Abstract
Mutations in the human ether‑à‑go‑go‑related gene (hERG) are responsible for long‑QT syndrome (LQTS) type 2 (LQT2). In the present study, a heterozygous missense mutation (A561V) linked to LQT2, syncope and epilepsy was identified in the S5/pore region of the hERG protein. The mutation, A561V, was prepared and subcloned into hERG‑pcDNA3.0. Mutant plasmids were co‑transfected into HEK‑293 cells, which stably express wild‑type (WT) hERG, in order to mimic a heterozygous genotype, and the whole‑cell current was recorded using a patch‑clamp technique. Confocal microscopy was performed to evaluate the membrane distribution of the hERG channel protein using a green fluorescent protein tagged to the N‑terminus of hERG. A561V‑hERG decreased the amplitude of the WT‑hERG currents in a concentration‑dependent manner. In addition, A561V‑hERG resulted in alterations to activation, inactivation and recovery from inactivation in the hERG protein channels. Further evaluation of hERG membrane localization indicated that the A561V‑hERG mutant protein was unable to travel to the plasma membrane, which resulted in a trafficking‑deficient WT‑hERG protein. In conclusion, A561V‑hERG exerts a potent dominant‑negative effect on WT‑hERG channels, resulting in decreased hERG currents and impairment of hERG membrane localization. This may partially elucidate the clinical manifestations of LQTS patients who carry the A561V mutation.
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Affiliation(s)
- GUOLIANG LI
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - RUI SHI
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - JINE WU
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - WENQI HAN
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - AIFENG ZHANG
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710004, P.R. China
| | - GONG CHENG
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi 710068, P.R. China
| | - XIAOLIN XUE
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
| | - CHAOFENG SUN
- Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University Health Science Center, Xi'an, Shaanxi 710061, P.R. China
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Vonderlin N, Fischer F, Zitron E, Seyler C, Scherer D, Thomas D, Katus HA, Scholz EP. Anesthetic drug midazolam inhibits cardiac human ether-à-go-go-related gene channels: mode of action. Drug Des Devel Ther 2015; 9:867-77. [PMID: 25733807 PMCID: PMC4338257 DOI: 10.2147/dddt.s72765] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Midazolam is a short-acting benzodiazepine that is in wide clinical use as an anxiolytic, sedative, hypnotic, and anticonvulsant. Midazolam has been shown to inhibit ion channels, including calcium and potassium channels. So far, the effects of midazolam on cardiac human ether-à-go-go-related gene (hERG) channels have not been analyzed. The inhibitory effects of midazolam on heterologously expressed hERG channels were analyzed in Xenopus oocytes using the double-electrode voltage clamp technique. We found that midazolam inhibits hERG channels in a concentration-dependent manner, yielding an IC50 of 170 μM in Xenopus oocytes. When analyzed in a HEK 293 cell line using the patch-clamp technique, the IC50 was 13.6 μM. Midazolam resulted in a small negative shift of the activation curve of hERG channels. However, steady-state inactivation was not significantly affected. We further show that inhibition is state-dependent, occurring within the open and inactivated but not in the closed state. There was no frequency dependence of block. Using the hERG pore mutants F656A and Y652A we provide evidence that midazolam uses a classical binding site within the channel pore. Analyzing the subacute effects of midazolam on hERG channel trafficking, we further found that midazolam does not affect channel surface expression. Taken together, we show that the anesthetic midazolam is a low-affinity inhibitor of cardiac hERG channels without additional effects on channel surface expression. These data add to the current understanding of the pharmacological profile of the anesthetic midazolam.
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Affiliation(s)
- Nadine Vonderlin
- Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany
| | - Fathima Fischer
- Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany
| | - Edgar Zitron
- Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany ; German Centre for Cardiovascular Research, Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Claudia Seyler
- Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany
| | - Daniel Scherer
- Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany
| | - Dierk Thomas
- Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany ; German Centre for Cardiovascular Research, Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Hugo A Katus
- Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany ; German Centre for Cardiovascular Research, Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Eberhard P Scholz
- Department of Internal Medicine III, University Hospital Heidelberg, Heidelberg, Germany
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Li G, Hu Z, Yin H, Zhang Y, Huang X, Wang S, Li W. A novel dendritic nanocarrier of polyamidoamine-polyethylene glycol-cyclic RGD for "smart" small interfering RNA delivery and in vitro antitumor effects by human ether-à-go-go-related gene silencing in anaplastic thyroid carcinoma cells. Int J Nanomedicine 2013; 8:1293-306. [PMID: 23569377 PMCID: PMC3615931 DOI: 10.2147/ijn.s41555] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The application of RNA interference techniques is promising in gene therapeutic approaches, especially for cancers. To improve safety and efficiency of small interfering RNA (siRNA) delivery, a triblock dendritic nanocarrier, polyamidoamine-polyethylene glycol-cyclic RGD (PAMAM-PEG-cRGD), was developed and studied as an siRNA vector targeting the human ether-à-go-go-related gene (hERG) in human anaplastic thyroid carcinoma cells. Structure characterization, particle size, zeta potential, and gel retardation assay confirmed that complete triblock components were successfully synthesized with effective binding capacity of siRNA in this triblock nanocarrier. Cytotoxicity data indicated that conjugation of PEG significantly alleviated cytotoxicity when compared with unmodified PAMAM. PAMAM-PEG-cRGD exerted potent siRNA cellular internalization in which transfection efficiency measured by flow cytometry was up to 68% when the charge ratio (N/P ratio) was 3.5. Ligand-receptor affinity together with electrostatic interaction should be involved in the nano-siRNA endocytosis mechanism and we then proved that attachment of cRGD enhanced cellular uptake via RGD-integrin recognition. Gene silencing was evaluated by reverse transcription polymerase chain reaction and PAMAM-PEG-cRGD-siRNA complex downregulated the expression of hERG to 26.3% of the control value. Furthermore, gene knockdown of hERG elicited growth suppression as well as activated apoptosis by means of abolishing vascular endothelial growth factor secretion and triggering caspase-3 cascade in anaplastic thyroid carcinoma cells. Our study demonstrates that this novel triblock polymer, PAMAM-PEG-cRGD, exhibits negligible cytotoxicity, effective transfection, “smart” cancer targeting, and therefore is a promising siRNA nanocarrier.
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Affiliation(s)
- Guanhua Li
- Department of Vascular and Thyroid Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, People's Republic of China
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Lu HR, Yan GX, Gallacher DJ. A new biomarker--index of cardiac electrophysiological balance (iCEB)--plays an important role in drug-induced cardiac arrhythmias: beyond QT-prolongation and Torsades de Pointes (TdPs). J Pharmacol Toxicol Methods 2013; 68:250-259. [PMID: 23337247 DOI: 10.1016/j.vascn.2013.01.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/02/2013] [Accepted: 01/05/2013] [Indexed: 12/15/2022]
Abstract
INTRODUCTION In the present study, we investigated whether a new biomarker - index of cardiac electrophysiological balance (iCEB=QT/QRS) - could predict drug-induced cardiac arrhythmias (CAs), including ventricular tachycardia/ventricular fibrillation (VT/VF) and Torsades de Pointes (TdPs). METHODS The rabbit left ventricular arterially-perfused-wedge was used to investigate whether the simple iCEB measured from the ECG is reflective of the more difficult measurement of λ (effective refractory period×conduction velocity) for predicting CAs induced by a number of drugs. RESULTS Dofetilide concentration-dependently increased iCEB and λ, predicting potential risk of drug-induced incidence of early afterdepolarizations (EADs) starting at 0.01μM. Digoxin (1 and 5μM), encainide (5 and 20μM) and propoxyphene (10 and 100μM) markedly reduced both iCEB and λ, predicting their ability to induce non-TdP-like VT/VF. At 10μM, both NS1643 and levcromakalim significantly decreased λ and iCEB, which was preceded with presence of non-TdP-like VT/VF. Isoprenaline (0.05 to 0.5μM) significantly reduced both λ and iCEB, which was associated with a high incidence of non-TdP-like VT/VF in most preparations. Other biomarkers (i.e. transmural dispersion of T-wave and instability of the QT interval) predicted only dofetilide-induced long QT and EADs, but did not predict drug-induced risk of non-TdP-like VT/VF. DISCUSSION Our data from 7 reference drugs of known pro-arrhythmic effects suggests that 1) this non-invasive iCEB predicts potential risk of drug-induced CAs beyond long QT and TdP; 2) iCEB is more useful than the current biomarkers (i.e. transmural dispersion and instability) in predicting potential risks for drug-induced non-TdP-like VT/VF.
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Affiliation(s)
- Hua Rong Lu
- Janssen Research and Development, Janssen Pharmaceutica NV, Belgium.
| | - Gan-Xin Yan
- Main Line Health Heart Center and Lankenau Institute for Medical Research, Wynnewood, PA, USA
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