Discovery of Clinically Approved Agents That Promote Suppression of Cystic Fibrosis Transmembrane Conductance Regulator Nonsense Mutations
- 1 November 2016
- journal article
- research article
- Published by American Thoracic Society in American Journal of Respiratory and Critical Care Medicine
- Vol. 194 (9), 1092-1103
- https://doi.org/10.1164/rccm.201601-0154oc
Abstract
Rationale: Premature termination codons (PTCs) in the cystic fibrosis transmembrane conductance regulator (CFTR) gene cause cystic fibrosis (CF). Several agents are known to suppress PTCs but are poorly efficacious or toxic. Objectives: To determine whether there are clinically available agents that elicit translational readthrough and improve CFTR function sufficient to confer therapeutic benefit to patients with CF with PTCs. Methods: Two independent screens, firefly luciferase and CFTR-mediated transepithelial chloride conductance assay, were performed on a library of 1,600 clinically approved compounds using fisher rat thyroid cells stably transfected with stop codons. Select agents were further evaluated using secondary screening assays including short circuit current analysis on primary cells from patients with CF. In addition, the effect of CFTR modulators (ivacaftor) was tested in combination with the most efficacious agents. Measurements and Main Results: From the primary screen, 48 agents were selected as potentially active. Following confirmatory tests in the transepithelial chloride conductance assay and prioritizing agents based on favorable pharmacologic properties, eight agents were advanced for secondary screening. Ivacaftor significantly increased short circuit current following forskolin stimulation in cells treated with pyranoradine tetraphosphate, potassium p-aminobenzoate, and escin as compared with vehicle control. Escin, an herbal agent, consistently induced readthrough activity as demonstrated by enhanced CFTR expression and function in vitro. Conclusions: Clinically approved drugs identified as potential readthrough agents, in combination with ivacaftor, may induce nonsense suppression to restore therapeutic levels of CFTR function. One or more agents may be suitable to advance to human testing.Keywords
This publication has 39 references indexed in Scilit:
- ROCK Inhibitor and Feeder Cells Induce the Conditional Reprogramming of Epithelial CellsThe American Journal of Pathology, 2012
- A CFTR Potentiator in Patients with Cystic Fibrosis and theG551DMutationNew England Journal of Medicine, 2011
- Correction of the F508del-CFTR protein processing defect in vitro by the investigational drug VX-809Proceedings of the National Academy of Sciences of the United States of America, 2011
- Ca2+−dependent contraction by the saponoside escin in rat vena cava: Implications in venotonic treatment of varicose veinsJournal of Vascular Surgery, 2011
- Suppression of CFTR premature termination codons and rescue of CFTR protein and function by the synthetic aminoglycoside NB54Journal of Molecular Medicine, 2011
- Inhibition of eukaryotic translation elongation by cycloheximide and lactimidomycinNature Chemical Biology, 2010
- Rescue of CF airway epithelial cell function in vitro by a CFTR potentiator, VX-770Proceedings of the National Academy of Sciences of the United States of America, 2009
- Mechanism of PTC124 activity in cell-based luciferase assays of nonsense codon suppressionProceedings of the National Academy of Sciences of the United States of America, 2009
- No Detectable Improvements in Cystic Fibrosis Transmembrane Conductance Regulator by Nasal Aminoglycosides in Patients with Cystic Fibrosis with Stop MutationsAmerican Journal of Respiratory Cell and Molecular Biology, 2007
- In vitroprediction of stop-codon suppression by intravenous gentamicin in patients with cystic fibrosis: a pilot studyBMC Medicine, 2007