Decitabine reverses TGF-β1-induced epithelial–mesenchymal transition in non-small-cell lung cancer by regulating miR-200/ZEB axis

OBJECTIVE: Epithelial–mesenchymal transition (EMT) is a crucial driver of tumor progression. Tumor growth factor-beta 1 (TGF-β1) is an important factor in EMT induction in tumorigenesis. The targeting of EMT may, therefore, represent a promising approach in anticancer treatment. METHODS: In this study, we determined the effect of decitabine, a DNA methyltransferase inhibitor, on TGF-β1-induced EMT in non-small-cell lung cancer (NSCLC) PC9 and A549 cells. We also assessed the involvement of the miR-200/ZEB axis. RESULTS: Decitabine reversed TGF-β1-induced EMT in PC9 cells, but not in A549 cells. This phenomenon was associated with epigenetic changes in the miR-200 family, which regulated EMT by altering the expression of ZEB1 and ZEB2. TGF-β1 induced aberrant methylation in miR-200 promoters, leading to EMT in PC9 cells. Decitabine attenuated this effect and inhibited tumor cell migration in vitro and in vivo. In A549 cells, however, neither TGF-β1 nor decitabine exhibited an effect on miR-200 promoter methylation. CONCLUSION: Our findings suggest that epigenetic regulation of the miR-200/ZEB axis is responsible for EMT induction by TGF-β1 in PC9 cells. Decitabine inhibits EMT in NSCLC cell PC9 through its epigenetic-based therapeutic activity.