Caspase-8 Activation and Bid Cleavage Contribute to MCF7 Cellular Execution in a Caspase-3-dependent Manner during Staurosporine-mediated Apoptosis*

There are at least two distinct classes of caspases, initiators (e.g. caspases-8, -9, and -10) and effectors (e.g. caspase-3). Furthermore, it is believed that there are two distinct primary apoptotic signaling pathways, one of which is mediated by death receptors controlled by caspases-8/10, and the other by the release of cytochrome c and activation of a caspase-9/Apaf1/cytochrome c apoptosome. However, several recent reports have …