Inhibitory effect of β-elemene on human breast cancer cells.

It has been approved for the clinical application of β-elemene to treat various cancers mainly brain tumors in China. In the present study, we found that β-elemene significantly inhibited the in vitro growth of human breast cancer cells by inducing apoptosis. In addition, β-elemene also induced the conversion of LC3-I into LC3-II as well as the formation of autolysosomes, indicating the activation of autophagy. Interestingly, inhibition of autophagy significantly potentiated the growth-inhibitory effect of β-elemene on breast cancer cells. In summary, β-elemene induced cytoprotective autophagy in human breast cancer cells in addition to apoptosis. Inhibition of autophagy significantly enhanced the cytotoxicity of β-elemene to human breast cancer cells. Therefore, combination of β-elemene with autophagy inhibitors could be a promising strategy for the treatment of breast cancer.