Fig. 4. NR inhibits the proliferation and migration of HCT116 cells. (A) The effect of drug treatment on cell grwoth was analyzed by counting cell numbers. HCT116 cells were grown for 5 days followed by treatment with 10 µM and 20 µM of NR, or 1 µM and 3 µM of 5-FU from 0 to 5 days. For exmaming the combination effect, cells were co-treated with 10 µM NR and 5-FU (1 µM and 3 µM). (B) HCT116 cells were treated with the indicated doses of NR for 24 h, and cell viability was measured by WST assay. (C) HCT116 cells were treated with various concentrations of NR for 24 h, and the cells were cultured for 14 days before staining with crystal violet solution (left). The stained colonies were counted, and the relative amounts are shown in a graph (right). (D) HCT116 cells were treated with different doses of NR for 36 h, and cell migration was examined by a wound-healing assay. Images of the migrated cells were taken under ×200 magnification (left), and the open wound area was measured using ImageJ and presented in a bar graph (right). Error bars represent SD, *p< 0.05, **p<0.01, ***p<0.001, ****p<0.0001. (E) HCT116 cells were treated with 30 µM or 50 µM NR for 24 h and then performed transwell migration assays (left), and the relative percentage of migratory cells was calculated (right). Error bars represent SD, *p< 0.05, **p<0.01, ***p<0.001, ****p<0.0001.