Ani9, A Novel Potent Small-Molecule ANO1 Inhibitor with Negligible Effect on ANO2

• Published in: PloS one Vol. 11; no. 5; p. e0155771
• Main Authors: Seo, Yohan, Lee, Ho K., Park, Jinhong, Jeon, Dong-kyu, Jo, Sungwoo, Jo, Minjae, Namkung, Wan
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 24.05.2016; Public Library of Science (PLoS)
• Subjects: Acetamides - pharmacology; Acids; Amino acids; Anoctamin-1; Anoctamins; Asthma; Biology and Life Sciences; Calcium; Calcium (intracellular); Calcium - metabolism; Calcium chloride; Calcium signalling; Cancer; Cell adhesion & migration; Cell culture; Cell Line; Channel gating; Chloride; Chloride channels (calcium-gated); Chloride Channels - antagonists & inhibitors; Chloride Channels - genetics; Chloride currents; Diarrhea; Gene Expression Regulation - drug effects; Genetic aspects; High-throughput screening; High-Throughput Screening Assays; Homology; Humans; Hydrazones - pharmacology; Hypertension; Inhibitors; Intracellular signalling; Ion channels; Medicine and Health Sciences; Membrane proteins; Membrane Proteins - genetics; Membrane Proteins - metabolism; Muscle contraction; Muscles; Neoplasm Proteins - antagonists & inhibitors; Neoplasm Proteins - genetics; Pain; Pain perception; Penicillin; Pharmaceutical sciences; Pharmacology; Pharmacy; Physical Sciences; Physiological aspects; Prostate cancer; Proteins; Pulmonary arteries; Pulmonary hypertension; Rodents; Screening; Secretion; Selectivity; Sequence Homology, Amino Acid; Small Molecule Libraries - pharmacology; Smooth muscle; Squamous cell carcinoma; Veins & arteries; Viruses; South Korea
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0155771

Anoctamin1 (ANO1)/transmembrane protein 16A (TMEM16A), a calcium-activated chloride channel (CaCC), is involved in many physiological functions such as fluid secretion, smooth muscle contraction, nociception and cancer progression. To date, only a few ANO1 inhibitors have been described, and these have low potency and selectivity for ANO1. Here, we performed a high-throughput screening to identify highly potent and selective small molecule inhibitors of ANO1. Three novel ANO1 inhibitors were discovered from screening of 54,400 synthetic small molecules, and they were found to fully block ANO1 channel activity with an IC50 < 3 μM. Electrophysiological analysis revealed that the most potent inhibitor, 2-(4-chloro-2-methylphenoxy)-N-[(2-methoxyphenyl)methylideneamino]-acetamide (Ani9), completely inhibited ANO1 chloride current with submicromolar potency. Notably, unlike previous small-molecule ANO1 inhibitors identified to date, Ani9 displayed high selectivity for ANO1 as compared to ANO2, which shares a high amino acid homology to ANO1. In addition, Ani9 did not affect the intracellular calcium signaling and CFTR chloride channel activity. Our results suggest that Ani9 may be a useful pharmacological tool for studying ANO1 and a potential development candidate for drug therapy of cancer, hypertension, pain, diarrhea and asthma.