Figure 1.

Induction of cell death in hepatoma cells by tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) in combination with histone deacetylase inhibitors (HDI) or cytostatics. Twenty‐four hours after administration of cytotoxic compounds, cells were exposed to TRAIL for another 24 h. (a) DNA fragmentation was determined by flow cytometric cell cycle analysis; apoptotic cells were detected as sub‐G₁ peak. (b) Cell death was determined by lactate dehydrogenase (LDH) release assay. (c) Caspase‐3 activity was determined using the fluorogenic substrate Ac‐DEVD‐AFC; relative caspase‐3 activities are the ratio of treated cells to untreated cells. (d) PARP‐1 cleavage was determined by Western blotting using an anti‐PARP‐1 monoclonal antibody; equal protein loading was confirmed with an anti‐glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) monoclonal antibody. (a–c) Means ± SEM of each three separate experiments are shown. (d) Results are representative of two separate experiments.