Down-regulation of NDRG2 sensitized Hela cells to cisplatin. Hela cells were transfected with pSilencer3.1 constructs expressing NDRG2-specific siRNA (siNDRG2) or scramble control. The G418-resistant mix clones were selected for further assays. A. The colony-formation ability of Hela cells and their variants was evaluated in the presence or absence of cisplatin (CDDP). B. Cell viability was evaluated by MTT assay as described in “Materials and Methods” and plotted against CDDP concentration. C. The IC50 values were determined according to the plot. * p < 0.01 vs Hela and scramble control. D. Down-regulation of NDRG2 in stable clones was displayed by Western blot with β-actin as loading control. Shown are representative of 3 independent experiments. * p < 0.01 vs Hela and scramble control. # p < 0.05 vs Hela and scramble control.