Figure 9.

Dissection of CAP-mediated apoptosis into three kinetically defined processes. (A) MKN-45 cells in medium (“M + C”) were not pretreated (control) or treated with CAP for 1 min in the absence or presence of either 2 mM of the singlet oxygen (¹O₂) scavenger histidine, 25 µM of the peroxynitrite (ONOO⁻) decomposition catalyst FeTPPS or 100 µM of the NOX1 inhibitor AEBSF. The assays were incubated after CAP treatment for the indicated times (without any washing steps). (B) MKN-45 cells were not pretreated or treated for 1 min with CAP in the absence or presence of the indicated inhibitors. The assays were further incubated for 25 min and then subjected to three cycles of washing. The cells were resuspended in fresh medium and further incubated, as indicated. (C) The tumor cells were treated with CAP for 1 min in the absence or presence of the indicated inhibitors. Immediately after CAP treatment, the cells were subjected to three cycles of washing, resuspended in fresh medium and cultivated further, as indicated. In all assays, time zero in is the beginning of CAP treatment. The data show that experimental modifications after CAP treatment allow to define three kinetically different processes.