Figure 4. Caspase 2 is activated early and suppresses death induced by MRZ and BTZ.
(a) Images of BiFC-Venus caspase 2 fluorescence (green) following treatment with 290 nM MRZ or 15 nM BTZ (IC50 doses) (red = dsRed mito). (b) Quantification of average Venus BiFC intensity in LN18 cells from (a) (DMSO [N = 8 cells], BTZ [N = 14 cells], MRZ [N = 13 cells]). (c) Caspase 2 protein in LN18 cells stably expressing shCTRL and shCASP2. (d) Activation of caspase 2 in shCTRL and shCASP2 LN18 cells after 16 h of treatment with 100 nM MRZ or BTZ. (e) Caspase 3/7 activity in shCTRL and shCASP2 LN18 cells after 16 h of treatment with MRZ or BTZ. (f) DNA fragmentation in shCTRL and shCASP2 LN18 cells treated for 48 h with MRZ or BTZ. *p < 0.05. All error bars represent the standard error of the mean for N = 3 independent experiments.