Figure 5. Involvement of mitochondrial pathway and death receptor pathway in dicycloplatin-induced apoptosis in HepG2 cells.

After HepG2 cells were treated with 30 to 120 µmol/L dicycloplatin or 25 to 100 µmol/L carboplatin for 48 h, respectively, the mitochondria and cytosolic fractions or the whole-cell lysates were assayed by Western blot analysis with the corresponding antibodies. A, mitochondrial cytochrome c release into cytosol and the cytochrome c in mitochondria. Cox-4 detection was used to confirm that the complete separation of cytochrome c in the mitochondrial and cytosolic fractions. B, activations of caspase-9 and caspase-3 and the cleavage of PARP in dose-dependent manner were observed. In addition, both dicycloplatin and carboplatin could down-regulate the expression of Bcl-2 and up-regulate that of Bad but did not influence the level of Bax. Moreover, activations of caspase-8 and decrease of native Bid were also observed.