Fig. 4

miR-148a suppresses luciferase reporter activity of DNMT1 3′UTR in NSCLC cells. Luciferase reporter assay was performed in A549 (A–C) and H1650 cells (D–F) co-transfected with an miR-148a mimic or an miR-148a inhibitor at a final concentration of 50 nM in combination with DNMT1-WT/MT-3′UTR reporter in a 96-well plate using Lipofectamine® RNAiMAX following the manufacturer's instructions. Some cells were incubated for 24 h after transfection, and others were subsequently treated with 10 mM metformin for 72 h. Luciferase activities were measured using a Gaussia luciferase assay kit (Promega) according to the manufacturer's protocol. Data represent mean ± standard deviation (SD) from three independent experiments. *P < 0.05, **P < 0.05, ***P < 0.001