ΔPEST Hax-1 strongly attenuates apoptosis. A. Knockdown efficiency of Hax-1 siRNA used in this study. B. H1299 cells were transfected with negative control (NC) or siRNA against Hax-1 and then treated with different doses of STS (2–10 nM) for 2 hours. Cells were double stained with annexin V-FITC and PI followed by FACS analyses. C. H1299 cells were transfected with NC or siRNA against Hax-1 and then treated with CCCP (10 μM) for 30 minutes. After CCCP treatment, cells were stained with a JC-1 mitochondrial membrane potential detection kit. D. H1299 cells were transfected with EGFP or EGFP-Hax-1 or EGFP-ΔPEST Hax-1. Forty-eight hours later, cells were treated with STS (20 nM) for 12 hours and stained with Hoechst 33342. E. Quantitative analysis of condensed nuclei from D with three independent experiments was performed; random field of 250 cells were counted. (means ± S.E.M., *p < 0.05, one-way ANOVA).