Figure 5.

NC inhibition of HCT116 cell proliferation is ERK-dependent. (A) The HCT116 cells were treated with NC (20 µM) and/or U0126 (10 µM) for 24 h and 48 h, and cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. (B) The HCT116 cells were treated with NC (20 µM) and/or U0126 (10 µM) for 40 h, and cell proliferation was measured by ³H-thymidine uptake assay. The results are presented as the mean ± standard deviation from three independent experiments. ^*P<0.05, ^**P<0.01 vs. the control group; ^#P<0.05, ^##P<0.01 vs. the cells treated with NC. NC, nitidine chloride; ERK, extracellular-signal-regulated kinase; U0, U0126; cpm, counts per minute.