Escin induces apoptosis in human renal cancer cells through G2/M arrest and reactive oxygen species-modulated mitochondrial pathways.

Escin, a natural pentacyclic triterpenoid compound, exhibits antitumor effects on various types of human cancer cells, but its effect on human renal cancer cells has not been fully elucidated. In the present study, we demonstrated that escin elicits cytotoxic effects on human renal cancer cells (786-O and Caki-1) in a dose-dependent manner, as determined by MTT assay. Escin induced G2/M arrest, and then increased the sub-G1 population, Annexin V binding, activation of caspase-9/-3, cleavage of poly(ADP-ribose) polymerase (PARP) and Bax protein. Escin also decreased the anti-apoptotic protein levels of Bcl-2, X-linked inhibitor of apoptosis protein and survivin. In addition, escin induced reactive oxygen species (ROS) generation, leading to mitochondrial membrane potential dysfunction and inducing apoptosis in 786-O renal cancer cells, which were suppressed by antioxidants, such as NAC. Collectively, our results suggest that escin induces apoptosis via the intrinsic-mitochondrial apoptosis pathway through G2/M arrest and ROS generation in human renal cancer cells. Escin appears to have potential as a clinically useful chemotherapeutic agent for human renal cancer.