Figure 2.

Induction of cell apoptosis by the combination of sorafenib and ATRA. (A) HepG₂ and (B) SMMC-7721 cells were treated with sorafenib (5 μM), ATRA (10 μM for HepG₂ cells and 0.1 μM for SMMC-7721 cells) alone or in combination for 48 h, after which the late stage of cell apoptosis was assessed by Hoechst 33258 staining assay. (C) HepG₂ and (D) SMMC-7721 cells were treated with sorafenib (10 μM), ATRA (10 μM for HepG₂ cells and 0.1 μM for SMMC-7721 cells) alone or in combination for 8 h, after which the early stage of cell apoptosis was measured by flow cytometric analysis. Data represent the mean ± SEM of three independent experiments, and representative images are shown. The apoptosis of cells was observed at a magnification of ×20. ^*p<0.05 vs. vehicle control; ^#p<0.05 vs. single-agent treatment.