Effects of miR-155 on the apoptosis of MEC-1 cells. (A) MEC-1 cells were transfected with siSTAT6, miR-155 and anti-miR-155, and subsequently treated with rIL-4 for 20 h. Apoptosis and necrosis levels of MEC-1 cells were determined using flow cytometry. (B) Quantification of the flow cytometry apoptosis data. Columns indicate the mean apoptosis rate of three repeats. Error bars represent the standard deviation. *P<0.05 and ***P<0.001. (C) Caspase-3 activation, measured by relative levels of cleaved protein, was determined by western blot analysis. *P<0.05 vs. control group; #P<0.05 vs. rIL-4 treated group. Data are presented as the mean ± standard deviation of at least 3 independent experiments, and the exact values were as follows: Con Group=1±0.0153 (n=5); IL-4 group=0.9146±0.01809 (n=5); siSTAT6 group=6.069±0.1752 (n=5); siSTAT6+IL-4 group=3.543±0.09789 (n=5); miR-155 group=0.3274±0.01877 (n=5); miR-155+IL-4 group=0.2609±0.008641 (n=5); anti-miR-155 group=7.39±0.1753 (n=5); and anti-miR-155 + IL-4 group=6.753±0.1842 (n=5). miR, microRNA; si, small interfering; STAT6, signal transducer and activator of transcription 6; rIL-4, recombinant interleukin 4; PI, propidium iodide; Con, control; NS, not significant.