Although the apoptosis mechanisms induced by sinularin require further investigation, we clearly demonstrated in this study that sinularin caused PARP-mediated apoptosis of HCC via activation of cascade caspases such as caspase 3, 8, and 9 as well as by repressing Bcl-2 expression and activating Bax, which is subsequently down-regulated in HCC (Fig. 5). This evidence concerns the gene CASP3 and hepatocellular carcinoma.