Fig. 3.

Down-regulation of XIAP and Bcl-2 levels and activation of caspase-3. HeLa cells were treated with the indicated concentrations of SAHA, sirtinol or cisplatin, alone or as SAHA/cisplatin or sirtinol/cisplatin combinations, for 24 hours and then analyzed by immunoblotting. (A, B, D, and E) SAHA (0, 2.5, 5, or 10 µm) or sirtinol (0, 12.5, 25, or 50 µm) induced a dose-dependent reduction in XIAP and Bcl-2 levels. (C) Induction of the cleaved (activated) form of caspase-3 by SAHA (2.5 µm) and cisplatin (20 µm) alone, and by combined SAHA (2.5 µm)/cisplatin (20 µm) treatment. (F) Induction of the cleaved (activated) form of caspase-3 by sirtinol (25 µm) and cisplatin (20 µm) alone, and by combined sirtinol (25 µm)/cisplatin (20 µm) treatment.