Effect of COA-Cl on transforming growth factor-β1-induced epithelialemesenchymal transition in RLE/Abca3 cells

Transforming growth factor (TGF)-beta 1 has received much attention as a major inducer of epithelial-mesenchymal transition (EMT) in pathological conditions such as cancer and organ fibrosis. In this study, we examined the effect of a novel nucleic acid analog, COA-Cl, on TGF-beta 1-induced EMT using RLE/Abca3, a cell line having alveolar type II cell-like phenotype. Changes in the cell morphology consistent with EMT were induced by TGF-beta 1, whereas, this response was suppressed by co-treatment of the cells with COA-Cl. In addition, co-treatment with COA-Cl abolished TGF-beta 1-induced downregulation of cytokeratin 19 and upregulation of alpha-smooth muscle actin transcripts. In order to delineate the mechanism underlying the inhibitory effect of COA-Cl on TGF-beta 1-induced EMT in RLE/Abca3 cells, we examined the role of zinc finger E-box binding homeobox (ZEB) family transcription factors in this phenomenon. Our results demonstrated that the treatment of cells with COA-Cl suppressed the TGF-beta 1-mediated increase in the mRNA levels of ZEB2. Overall, it was concluded that COA-Cl may have an inhibitory effect on TGF-beta 1-induced EMT-like phenotypical changes in RLE/Abca3 cells via suppression of ZEB2 mRNA expression. (C) 2017 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.