Figure 3: Ate1 reduction in prostate cancer cells promotes stress resistance.

(A) Top panel shows representative Western blot of Ate1 and actin (loading control) for PC-3 cells, which were stably infected with two different shRNAs (#1 and #2) targeting Ate1, or the nonsilencing control. PC3-ML cells, which have naturally lower level of Ate1 compared to the parental PC3 cells, were used as another control. Bottom panel shows quantification from three independent repeats, showing that sh-ATE1#1 has 40–60% efficiency, while #2 has >95% efficiency. For this reason #2 is used for knockdown of Ate1 through this study unless otherwise specified. (B) Similarly as done in (A), Western blots and their corresponding quantifications were presented for LNCaP (C) PC-3 and LNCaP cells either transduced with shRNA against Ate1 or non-silencing control or non-transduced were treated with various doses of H₂O₂ or Staurosporine for 12 hours, or a single dose of Gamma irradiation followed by 24 hours of recovery, then assessed for cell viability via Calcein AM staining. Graphs showing quantification from three independent experiments. Error bars represent SEM. Statistical significance of group comparison at select data points were assessed with the Student’s t-test: * = p<0.05, *** = p<0.001. See also Supp. Fig. S4 for similar effects of Ate1 reduction on STS and gamma irradiation for human foreskin fibroblasts (HFF), a non-tumorigenic primary cell line.