miR-664 decreases apoptosis in lung cancer cells. (A) Caspase 3/7 activity in A549 cells transfected with miR-664 following cisplatin treatment. (B) Caspase 3/7 activity in A427 cells transfected with miR-664 following cisplatin treatment. (C) The level of apoptotic proteins in A549 and A427 cells following cisplatin treatment. Bar graph indicates the relative quantity of proteins on A549 and A427 cells following transfection with miR-664 mimic by densitometric analysis. P<0.05 represents a statistically significant difference vs. control. miR, microRNA; ctrl, control; OD, optical density; RFU, relative fluorescence units; Bcl-2, B-cell lymphoma-2; Bax, Bcl-2 associated X protein.