Knockdown of NRAS causes sensitivity to ER-stress in HT-1080 and RD human cancer cell lines. A and E, western blots showing expression and phosphorylation of the indicated proteins in lysates from HT-1080 cells (A) or RD cells (E) transfected with the indicated siRNA. B, Western blots showing phosphorylation or expression of the indicated proteins in lysates from HT-1080 cells transfected with the indicated siRNA. C, D, F and G, Relative viability (WST-1 assay) of HT-1080 cells (C and D) or RD cells (F and G) after transfection with the indicated siRNA, followed by treatment with 2 mM DTT (C and F) or 20 μg/ml Tm (D and G) for 24 h. Data show mean and S.E.M. of relative viability of stressed (DTT or Tm) compared to unstressed cells for each siRNA. * p < .05, ** p < .01, *** p < .001, unpaired t-test comparing to siCtrl, n = 3. H and I, western blots showing expression of the indicated proteins in lysates from HT-1080 cells (H) or RD cells (I) transfected with the indicated siRNA, then treated with DTT for the indicated times. U/T = untransfected, western blots are representative of three experiments.