Fig. 3

miR-148b negatively regulates DNMT1 and DNMT3b expression in A549 cells. A Sequences of miR-148/-152 precursor family members targeting DNMT1 3′UTR. B, C miR-148b-3p precursor was cloned into a pEZX-MT04 vector. miR-148b-3p plasmid (B) or miR-148b-3p mimic or inhibitor (C) was transfected into A549 cells using Lipofectamine® RNAiMAX. Cells were cultured for 24 h after transfection and then treated with 10 mM metformin for an additional 72 h. After 72 h, protein levels of DNMT1 and DNMT3b were determined using western blot, and α-tubulin was used as an internal loading control. NC, scrambled oligonucleotides as a negative control. Data are presented as mean ± standard deviation (n = 3). Statistical analysis: *P < 0.05, **P < 0.05, ***P < 0.001