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Genes Jan 2020Retinoblastoma is the most common pediatric intraocular malignant tumor. Unfortunately, low cure rates and low life expectancy are observed in low-income countries....
Retinoblastoma is the most common pediatric intraocular malignant tumor. Unfortunately, low cure rates and low life expectancy are observed in low-income countries. Thus, alternative therapies are needed for patients who do not respond to current treatments or those with advanced cases of the disease. (Eag1) is a voltage-gated potassium channel involved in cancer. expression is upregulated by the human papilloma virus (HPV) oncogene E7, suggesting that retinoblastoma protein (pRb) may regulate . Astemizole is an antihistamine that is suggested to be repurposed for cancer treatment; it targets proteins implicated in cancer, including histamine receptors, ATP binding cassette transporters, and Eag channels. Here, we investigated Eag1 regulation using pRb and Eag1 expression in human retinoblastoma. The effect of astemizole on the cell proliferation of primary human retinoblastoma cultures was also studied. HeLa cervical cancer cells (HPV-positive and expressing Eag1) were transfected with . mRNA expression was studied using qPCR, and protein expression was assessed using western blotting and immunochemistry. Cell proliferation was evaluated with an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. transfection down-regulated Eag1 mRNA and protein expression. The human retinoblastoma samples displayed heterogeneous Eag1 mRNA and protein expression. Astemizole decreased cell proliferation in primary retinoblastoma cultures. Our results suggest that Eag1 mRNA and protein expression was regulated by pRb in vitro, and that human retinoblastoma tissues had heterogeneous Eag1 mRNA and protein expression. Furthermore, our results propose that the multitarget drug astemizole may have clinical relevance in patients with retinoblastoma, for instance, in those who do not respond to current treatments.
Topics: Astemizole; Cell Line, Tumor; Cell Proliferation; Child, Preschool; Ether-A-Go-Go Potassium Channels; Female; Gene Expression Regulation, Neoplastic; HeLa Cells; Humans; Infant; Male; Oncogenes; RNA, Messenger; Retinal Neoplasms; Retinoblastoma; Retinoblastoma Protein; Transfection
PubMed: 31973216
DOI: 10.3390/genes11020119 -
The Journal of Toxicological Sciences 2019The objective of this study is to assess the response of telemetered common marmosets to multiple cardiac ion channel inhibitors and to clarify the usefulness of this...
The objective of this study is to assess the response of telemetered common marmosets to multiple cardiac ion channel inhibitors and to clarify the usefulness of this animal model in evaluating the effects of drug candidates on electrocardiogram (ECG). Six multiple cardiac ion channel inhibitors (sotalol, astemizole, flecainide, quinidine, verapamil and terfenadine) were orally administered to telemetered common marmosets and changes in QTc, PR interval and QRS duration were evaluated. Drugs plasma levels were determined to compare the sensitivity in common marmosets to that in humans. QTc prolongation was observed in the marmosets dosed with sotalol, astemizole, flecainide, quinidine, verapamil and terfenadine. PR prolongation was noted after flecainide and verapamil administration, and QRS widening occurred following treatment with flecainide and quinidine. Drugs plasma levels associated with ECG changes in marmosets were similar to those in humans, except for verapamil-induced QTc prolongation. Verapamil-induced change is suggested due to body temperature decrease. These results indicate that telemetered common marmoset is a useful animal for evaluation of the ECG effects of multiple cardiac ion channel inhibitors and the influence of body temperature change should be considered in the assessment.
Topics: Animals; Astemizole; Body Temperature; Calcium Channel Blockers; Callithrix; Electrocardiography; Flecainide; Male; Models, Animal; Quinidine; Risk Assessment; Sotalol; Telemetry; Terfenadine; Verapamil; Voltage-Gated Sodium Channel Blockers
PubMed: 31270301
DOI: 10.2131/jts.44.441 -
JRSM Cardiovascular Disease 2019We investigated if there is I, and if there is repolarization reserve by I in human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).
OBJECTIVE
We investigated if there is I, and if there is repolarization reserve by I in human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).
DESIGN
We used a specific KCNQ1/KCNE1 channel blocker, L-000768673, with an IC of 9 nM, and four hERG-specific blockers, astemizole, cisapride, dofetilide, and E-4031 to investigate the issue.
RESULTS
L-000768673 concentration-dependently prolonged feature point duration (FPD)-a surrogate signal of action potential duration-from 1 to 30 nM without pacing or paced at 1.2 Hz, resulting from I blockade in hiPSC-CMs. At higher concentrations, the effect of L-000768673 on I was mitigated by its effect on I, resulting in shortened FPD, reduced impedance amplitude, and increased beating rate at 1 µM and above, recapitulating the self-limiting properties of L-000768673 on action potentials. All four hERG-specific blockers prolonged FPD as expected. Co-application of L-000768673 at sub-threshold (0.1 and 0.3 nM) and threshold (1 nM) concentrations failed to synergistically enhance the effects of hERG blockers on FPD prolongation, rather it showed additive effects, inconsistent with the repolarization reserve role of I in mature human myocytes that enhanced I response, implying a difference between hiPSC-CMs used in this study and mature human cardiomyocytes.
CONCLUSION
There was I current in hiPSC-CMs, and blockade of I current caused prolongation of action potential of hiPSC-CMs. However, we could not demonstrate any synergistic effects on action potential duration prolongation of hiPSC-CMs by blocking hERG current and I current simultaneously, implying little or no repolarization reserve by I current in hiPSC-CMs used in this study.
PubMed: 31217965
DOI: 10.1177/2048004019854919 -
Revista de Investigacion Clinica;... 2019Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for...
BACKGROUND
Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression.
OBJECTIVE
We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells.
MATERIALS AND METHODS
The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cy-tometry.
RESULTS
Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle.
CONCLUSIONS
Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.
Topics: Antineoplastic Agents; Astemizole; Breast Neoplasms; Cell Line, Tumor; Cell Proliferation; Dose-Response Relationship, Drug; Drug Synergism; ErbB Receptors; Ether-A-Go-Go Potassium Channels; Female; Gefitinib; Gene Expression Regulation, Neoplastic; Humans; Inhibitory Concentration 50; Protein Kinase Inhibitors
PubMed: 31184333
DOI: 10.24875/RIC.18002840 -
MedChemComm Apr 2019Based on the scaffold of astemizole, three novel turn-on fluorescent probes (-) for human ether-a-go-go-related gene (hERG) potassium channel were developed herein....
Based on the scaffold of astemizole, three novel turn-on fluorescent probes (-) for human ether-a-go-go-related gene (hERG) potassium channel were developed herein. These probes have reasonable fluorescence properties, acceptable cell toxicity, and potent inhibitory activity, all of which contribute to cell imaging at the nanomolar level. Overall, these probes have the potential for setting up a screening system for hERG channels.
PubMed: 31057730
DOI: 10.1039/c8md00562a -
Frontiers in Chemistry 2019Based on the scaffold of astemizole and E-4031, four AIE light-up probes () for Human Ether-a-go-go-Related Gene (hERG) potassium channel were developed herein using AIE...
Based on the scaffold of astemizole and E-4031, four AIE light-up probes () for Human Ether-a-go-go-Related Gene (hERG) potassium channel were developed herein using AIE fluorogen(TPE). These probes showing advantages such as low background interference, superior photostability, acceptable cell toxicity, and potent inhibitory activity, which could be used to image hERG channels at the nanomolar level. These AIE light-up probes hoped to provide guidelines for the design of more advanced AIE sensing and imaging hERG channels to a broad range of applications.
PubMed: 30800649
DOI: 10.3389/fchem.2019.00054 -
International Journal of Cancer Jul 2019Polycomb group proteins are important epigenetic regulators for cell proliferation and differentiation, organ development, as well as initiation and progression of...
Polycomb group proteins are important epigenetic regulators for cell proliferation and differentiation, organ development, as well as initiation and progression of lethal diseases, including cancer. Upregulated Polycomb group proteins, including Enhancer of zeste homolog 2 (EZH2), promote proliferation, migration, invasion and metastasis of cancer cells, as well as self-renewal of cancer stem cells. In our study, we report that EZH2 and embryonic ectoderm development (EED) indicate respective direct interaction with androgen receptor (AR). In the context of AR-positive prostate cancer, EZH2 and EED regulate AR expression levels and AR downstream targets. More importantly, we demonstrate that targeting EZH2 with the small-molecule inhibitor astemizole in cancer significantly represses the EZH2 and AR expression as well as the neoplastic capacities. These results collectively suggest that pharmacologically targeting EZH2 might be a promising strategy for advanced prostate cancer.
Topics: Animals; Astemizole; Cell Line, Tumor; Enhancer of Zeste Homolog 2 Protein; Gene Expression Regulation, Neoplastic; Humans; Male; Mice; Polycomb Repressive Complex 2; Prostatic Neoplasms; Receptors, Androgen; Sequence Analysis, RNA; Signal Transduction; Xenograft Model Antitumor Assays
PubMed: 30628724
DOI: 10.1002/ijc.32118 -
Scientific Reports Sep 2018We examined a simultaneous combined spatiotemporal field potential duration (FPD) and cell-to-cell conduction time (CT) in lined-up shaped human embryonic stem...
We examined a simultaneous combined spatiotemporal field potential duration (FPD) and cell-to-cell conduction time (CT) in lined-up shaped human embryonic stem cell-derived cardiomyocytes (hESC-CMs) using an on-chip multielectrode array (MEA) system to evaluate two origins of lethal arrhythmia, repolarization and depolarization. The repolarization index, FPD, was prolonged by E-4031 and astemizole, and shortened by verapamil, flecainide and terfenadine at 10 times higher than therapeutic plasma concentrations of each drug, but it did not change after lidocaine treatment up to 100 μM. CT was increased by astemizol, flecainide, terfenadine, and lidocaine at equivalent concentrations of Nav1.5 IC, suggesting that CT may be an index of cardiac depolarization because the increase in CT (i.e., decrease in cell-to-cell conduction speed) was relevant to Nav1.5 inhibition. Fluctuations (short-term variability; STV) of FPD and CT, STV and STV also discriminated between torsadogenic and non-torsadogenic compounds with significant increases in their fluctuation values, enabling precise prediction of arrhythmogenic risk as potential new indices.
Topics: Arrhythmias, Cardiac; Cell Line; Drug Development; Drug Evaluation, Preclinical; Equipment Design; Human Embryonic Stem Cells; Humans; Lab-On-A-Chip Devices; Myocytes, Cardiac
PubMed: 30266924
DOI: 10.1038/s41598-018-32921-1 -
Drug Metabolism Letters 2018We report here an evaluation of a novel experimental system- cofactorsupplemented permeabilized cryopreserved human enterocytes (MetMax™ cryopreserved human... (Comparative Study)
Comparative Study
A Novel In vitro Experimental System for the Evaluation of Enteric Drug Metabolism: Cofactor-Supplemented Permeabilized Cryopreserved Human Enterocytes (MetMax™ Cryopreserved Human Enterocytes).
BACKGROUND
We report here an evaluation of a novel experimental system- cofactorsupplemented permeabilized cryopreserved human enterocytes (MetMax™ cryopreserved human enterocytes (MMHE), patent pending) for applications in the evaluation of enteric drug metabolism. A major advantage of MMHE over Conventional Cryopreserved Human Enterocytes (CCHE) is the simplification of the use procedures including storage at -80°C instead of in liquid nitrogen, and use of the cells immediately after thawing without a need for centrifugation and microscopic evaluation of cell density and viability and cell density adjustment.
METHODS
In this study, we compared MMHE and CCHE in key phase 1 oxidation and phase 2 conjugation Drug Metabolism Enzyme (DME) activities that we recently reported for cryopreserved human enterocytes: CYP2C9 (diclofenac 4'- hydroxylation), CYP2C19 (s-mephenytoin hydroxylation), CYP3A4 (midazolam 1'-hydroxylation), CYP2J2 (astemizole O-demethylation), uridine 5'-diphosphoglucuronosyltransferase (UGT; 7-hydroxycoumarin glucuronidation), sulfotransferase (SULT; 7- hydroxycoumarin sulfation), N-acetyl transferase-1 (NAT-1; p-benzoic acid N-acetylation), and carboxyesterase- 2 (CES-2; hydrolysis of irinotecan to SN38). Both CCHE and MMHE were active in all the DME pathways evaluated, with specific activities of MMHE ranged from 142% (CYP2C9) to 1713% (UGT) of that for CCHE. β-hydroxylation and testosterone 6.
RESULT AND CONCLUSION
Our results suggest that the MMHE system represents a convenient and robust in vitro experimental system for the evaluation of enteric drug metabolism.
Topics: Adult; Biotransformation; Carboxylesterase; Cell Membrane Permeability; Cryopreservation; Cytochrome P-450 Enzyme System; Enterocytes; Female; Glucuronosyltransferase; Humans; In Vitro Techniques; Isoenzymes; Male; Middle Aged; Pharmaceutical Preparations; Sulfotransferases
PubMed: 30124163
DOI: 10.2174/1872312812666180820142141 -
International Journal of Biological... 2018Cholesterol plays a key role in membrane protein function and signaling in endothelial cells. Thus, disturbing cholesterol trafficking is an effective approach for...
Cholesterol plays a key role in membrane protein function and signaling in endothelial cells. Thus, disturbing cholesterol trafficking is an effective approach for inhibiting angiogenesis. We recently identified astemizole (AST), an antihistamine drug, as a cholesterol trafficking inhibitor from a phenotypic screen. In this study, we found that AST induced cholesterol accumulation in the lysosome by binding to the sterol-sensing domain of Niemann-Pick disease, type C1 (NPC1), a lysosomal surface protein responsible for cholesterol transport. Inhibition of cholesterol trafficking by AST led to the depletion of membrane cholesterol, causing SREBP1 nuclear localization. The depletion of membrane cholesterol resulted in dissociation of mammalian target of rapamycin (mTOR) from the lysosomal surface and inactivation of mTOR signaling. These effects were effectively rescued by addition of exogenous cholesterol. AST inhibited endothelial cell proliferation, migration and tube formation in a cholesterol-dependent manner. Furthermore, AST inhibited zebrafish angiogenesis in a cholesterol-dependent manner. Together, our data suggest that AST is a new class of NPC1 antagonist that inhibits cholesterol trafficking in endothelial cells and angiogenesis.
Topics: A549 Cells; Astemizole; Biological Transport; Blotting, Western; Cell Movement; Cell Proliferation; Cholesterol; Fluorescent Antibody Technique; Human Umbilical Vein Endothelial Cells; Humans; Neovascularization, Pathologic; Niemann-Pick C1 Protein; Signal Transduction; TOR Serine-Threonine Kinases
PubMed: 30123067
DOI: 10.7150/ijbs.26011