Figure 4
Analysis of cell death and caspases in MDA-MB-231 cells after PARG silencing or genetic disruption. A, MDA-MB-231 cells pretreated with the pan-caspase inhibitor, Q-VD-OPH (Q), were transfected with PARG siRNA. 48 h after transfection, cells were treated with 0.5 mM MNNG for 45 min, and 24 h later cell death was quantified by FACS. All error bars represent the SEM. *P < 0.01 between Scr and PARG or Scr and Scr + Q (one-way ANOVA and unpaired Student’s t-test). B, extracts from cells in A were probed for the immunoblotting detection of procaspase-8 levels. C, Procaspase-8 protein levels in B were quantified by densitometric analysis. Values represent procaspase-8/actin ratios of the densitometric intensities of the protein bands. D, Wild-type (WT) and PARG-null (KO) cells were treated with 25 J/m2 UV-C radiation and 12 h later caspase-3 (a), caspase-8 (b), and caspase-9 (c) activity was assayed. Q, pretreatment with Q-VD-OPh 30 min prior to UV treatment and until caspase activity assays. Error bars represent the SEM. *P < 0.01 between WT and KO (one-way ANOVA and unpaired Student’s t-test). RFU, relative fluorescence unit.