Tetrandrine triggers apoptosis and cell cycle arrest in human renal cell carcinoma cells

Tetrandrine is a cytotoxic compound capable of exerting remarkable antitumor activity against many cancer cells in vitro and in vivo. However, little is known about its effect on human renal cell carcinoma (RCC). In the present study, using RCC 786-O, 769-P and ACHN cell lines as the model system, we demonstrated the anticancer effect of tetrandrine against RCC and clarified its underlying mechanisms. Tetrandrine treatment showed growth inhibitory effects on RCC cells in a time- and dose-dependent manner. Additionally, flow cytometric studies revealed that tetrandrine was capable of inducing G1 cell cycle arrest and apoptosis in RCC cells. Mechanically, activation of caspase-8, caspase-9, and caspase-3 and increasing expression of cell cycle regulatory protein p21(WAF1/CIP1) and p27(KIP1) were observed in tetrandrine-treated RCC cells. This study provides the first evidence that tetrandrine triggered apoptosis and cell cycle arrest in RCC 786-O, 769-P and ACHN cells in vitro; these events are associated with caspase cascade activation and upregulation of p21 and p27. Our results thus provide rational evidence supporting the application of tetrandrine as a novel therapeutic agent against RCC in the clinical setting.