Fig. 1

Metformin suppresses protein expression and activity of DNMTs. A549 cells were treated with 0 mM, 5 mM, or 10 mM metformin for 72 h. A–C mRNA levels of DNMTs were measured by qRT‐PCR. D–F Protein levels of DNMTs were determined using western blot with α-tubulin as an internal loading control. G Nuclear proteins were extracted using an EpiQuik™ Nuclear Extraction Kit, and the activity level (OD/h/mg nuclear protein) of total DNMTs was measured using an EpiQuik™ DNA Methyltransferase Activity/Inhibition Assay Kit. Results are shown as mean ± standard deviation (n = 3). *P < 0.05, **P < 0.01, ***P < 0.001