Caspase-8 is scarcely silenced and its activity is well correlated with the anticancer effect of tumor necrosis factor-related apoptosis-inducing ligand in gastric cancer cells.

The main apoptotic signal stimulated by tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) streams through caspase-8 activation and evokes caspase-3, a central apoptosis activator. In this study, the status of caspase-8 and -3 in gastric cancer cells related to the anticancer effects of TRAIL was investigated. In the caspase-8 gene promoter, 9 of 10 gastric cancer cell lines harbor no hypermethylation. The pretreatment amounts of caspase-8 and -3 in these cells were not predictors for the anticancer effect of TRAIL. Caspase-8 activity 24 h after treatment with TRAIL was well correlated with the anticancer effect of TRAIL (r=0.777, p=0.0060). Caspase-3 activity 24 h after treatment with TRAIL showed a trend towards an association with the anticancer effect of TRAIL (r=0.544, p=0.1067). These results suggested that gastric cancer might be a good target of TRAIL therapy because the majority of tumor cells have intact caspase-8 expression. The anticancer efficacy may be predicted by the degree of caspase-8 activation after TRAIL treatment.