Figure 3

Up-regulating NDRG2 inhibits Eca-109 cell growth. A. Dose-dependent suppression of Eca-109 cell proliferation by Ad-NDRG2. Eca-109 cells were infected with various amounts of Ad-NDRG2 or Ad-LacZ (at MOI of 1, 10, and 100) and incubated for 48 h. Cell proliferation was detected by MTT assay. B. Time-dependent suppression of Eca-109 cell proliferation by Ad-NDRG2. After Ad-NDRG2 or Ad-LacZ infection at an MOI of 100, the cells were incubated for different time periods (24, 48 and 72 h). Cell proliferation was detected by MTT assay. C and D. The effect of Ad-NDRG2 on Eca-109 cell colony formation was examined. After Ad-NDRG2 or Ad-LacZ infection, the cells were incubated for approximately 10 days until visible cell colony formation. Only the clearly visible colonies (diameter > 50 μm) were counted. E and F. The effect of Ad-NDRG2 on Eca-109 cell DNA replication activity was examined. After Ad-NDRG2 or Ad-LacZ infection, the cells were incubated for 2 days and cultured with BrdU for 1 h and DAPI for nuclear counterstaining. The results were analysed using a fluorescence microscope; BrdU positive (red) cells were counted. Data are mean ± SD from three independent experiments. Statistical significance was assessed using a one-way ANOVA and Student’s t-test. * or ** indicates P < 0.05 or P < 0.01, respectively, compared to the control.