Is caspase-12 implicated in apoptosis?
Data in the literature provide a confusing picture of the role of caspase-12 in apoptosis. On the one hand, it has been proposed that caspase-12 is not processed and activated following serum deprivation in rat PC12 pheochromocytoma cells, in etoposide-treated ST14A cells, a rat striatum-derived neuronal progenitor cell line,11,12 or during TNF- and FasL-induced apoptosis in rat W4 fibrosarcoma cells.10 Serum withdrawal and etoposide treatment are well-known inducers of the intrinsic mitochondrial apoptotic pathway, while TNF- and FasL-induced apoptosis are examples of the well-studied extrinsic death receptor pathway. On the other hand, caspase-12 processing and activation has been detected in FasL-treated L929sAhFas fibrosarcoma cells and TNF–treated B16/Bl6 melanoma cells.7 During the mitochondrial apoptotic pathway, caspase-12 is processed in serum-deprived AKR-2B fibrosarcoma cells, in staurosporine-treated murine cortical neurons and MEF cells, and in etoposide-treated PC12 cell
