H2009 cells are refractory to miR-34a -induced cell cycle arrest. (A) DNA content distribution of NSCLC cells transfected with precursor miRNA or precursor control. Cells were treated for 18 h with nocodazole beginning 24 h post-transfection. (B) Percent difference in G1-G0 between cells transfected with pre-miR-34a and cells transfected with precursor control. H2009, A549, n = 3; H1299 and H358, n = 1. (C) mRNA levels of known miR-34a targets. H2009 cells were transfected with pre-miR-34a and harvested 42 h post-transfection (n = 3). Values are relative to the level obtained for the control transfected with precursor control.