Berbamine suppresses cell viability and induces apoptosis in colorectal cancer via activating p53-dependent apoptotic signaling pathway

Abstract

Berbamine has been shown to exhibit anti-cancer activities in various types of cancers. The effects of berbamine on colorectal colon cancer (CRC) have not been examined, and the present study aimed to investigate the anti-cancer effects of berbamine in CRC and explore its underlying molecular mechanisms. The effect of berbamine on the CRC cells was determined by MTT assay. Flow cytometry was performed to examine the effect of berbamine on cell apoptosis and cell cycle as well as mitochondrial membrane potential in CRC cell lines. The specific apoptosis-related factors were evaluated by western blot assay. In vivo anti-cancer effect of berbamine was assessed in SW480 xenografts. Berbamine suppressed the cell viability of CRC cells in concentration-dependent and time-dependent manners. Flow cytometry experiments showed that berbamine increased cell apoptotic rate and induced cell cycle arrest at G0/G1 phase. Berbamine treatment also decreased the mitochondrial membrane potential in CRC cells. Western blot assay showed that berbamine increased the protein levels of p53, caspase-3, caspase-9, Bax and poly ADP ribose polymerase, and decreased the protein levels of Bcl-2 in CRC cells. Berbamine failed to increase the cell apoptotic rate in p53 mutant CRC cell lines. Tumor growth by grafted SW480 cells were significantly suppressed in berbamine group. Expression of p53, caspase-3 and -9 in tumor tissues was significantly up-regulated by berbamine. Berbamine exerts anti-cancer effects in vitro and in vivo via induction of apoptosis, partially associated with the activation of p53-dependent apoptosis signaling pathway.