Figure. Dual treatment of Sa-Os2 cells with IL-2 (250 IU/mL, 48 hrs) and DEX (10^-9 M, 24 hrs) leads to alterations in mitochondrial integrity, commonly observed in GC-mediated apoptosis. We monitored mitochondrial dehydrogenase, and demonstrated that IL-2/DEX treatment is associated with a significant drop (p < 0.05) in this marker. Treatment of the cultures with either IL-2 alone or DEX alone fails to alter the levels of this marker of mitochondrial integrity. The results presented in this Fig. are expressed as mean 10x OX A₄₅₀ (± STD) of triplicate experimental values of one representative experiment. Four experiments produced identical trends and reproducible results. Taken together, these data confirm our suspicion that IL-2 treatment of Sa-Os2, which we showed to be associated with an increased number and binding of GC receptors, induces, when followed by exposure to DEX, apoptosis mediated via the mitochondrial pathway. This observation was also confirmed by flow cytometry with anti-caspase antibodies (Chiappelli et al., 2001b).