Hinokiflavone induces apoptosis and inhibits migration of breast cancer cells via EMT signalling pathway.

Hinokiflavone is a natural product, isolated from Selaginella P. Beauv, Juniperus phoenicea and Rhus succedanea. Even though hinokiflavone was reported to possess cytotoxicity to many cancer cells, and has potential in cancer treatment, the anti-proliferation and anti-metastasis efficacy of hinokiflavone on human breast cancer cells has not a further research. In this study, we investigated the anti-cancer activity of hinokiflavone in human breast cancer cells in vitro and in vivo. Hinokiflavone exhibited a time- and dose-dependent manner apoptosis induction by upregulating expression of Bax and downregulating Bcl-2 in breast cancer cells. Furthermore, hinokiflavone significantly inhibited the migration and invasion of breast cancer cells by impairing the process of epithelial-to-mesenchymal transition. In addition, the tumour growth was distinctly inhibited by treatment of hinokiflavone in a xenograft tumour mouse model of MDA-MB-231 cells. Immunohistochemical analysis of tumour sections showed that MMP-2⁺ cells and Ki-67⁺ cells were remarkably decreased in tumour tissues of mice after treatment of hinokiflavone, indicating that hinokiflavone inhibits not only proliferation but also metastasis of breast cancer cells. Our study suggested that hinokiflavone can be a potential drug to breast cancer. SIGNIFICANCE OF THE STUDY: Hinokiflavone significantly inhibited proliferation and induced apoptosis in breast cancer cells. In addition, hinokiflavone remarkably inhibited migration and invasion of breast cancer cells via EMT signalling pathway. It is worth noting that hinokiflavone possesses anti-tumour effect in tumour mouse xenograft model of breast cancer. Overall, our results indicated that hinokiflavone may be a potential anticancer drug for breast cancer treatment.