Fig. 2

a–d K562 cells were treated with various concentrations of TMQ0153 in presence or absence of the pan caspase inhibitor carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]-fluoromethylketone (z-VAD; 50 μM). a After 8, 24, 48, and 72 h of treatment the type of cell death triggered by TMQ0153 was characterized by fluorescence microscopy after Hoechst/propidium iodide (PI) staining. Pictures representative of three independent experiments (top panel). Etoposide (Eto; 100 µM, 24 h) was used as a positive control for apoptosis induction. Scale bar: 25 µM. b Analysis of caspase and poly [ADP-ribose] polymerase (PARP)-1 cleavage by western blot after 24 h of treatment. c Effect of 24 h of treatment on Mcl-1 and Bcl-xL protein expression levels (top panels) and the corresponding densitometric analysis (middle and lower panels). b, c β–actin was used as loading control. d Quantification of caspase-3/7 activity levels after 24 h of treatment. Etoposide (Eto; 100 µM, 24 h) was used as a positive control for apoptosis induction. All pictures are representative of three independent experiments and graphs represent the mean (±S.D.) of three independent experiments. Statistical significance was assessed as *p < 0.05, **p < 0.01, ***p < 0.001 compared to untreated cells. Two-way ANOVA (microscopy analysis); post hoc: Sidak’s test. One-way ANOVA (caspase-3/7 assay); post hoc: Tukey’s test. One-way ANOVA (western blot quantification); post hoc: Dunnett’s test.