Abstract
Morin, a flavonoid found in figs and other Moraceae, displays a variety of biological actions, such as anti-oxidant, anti-inflammatory and anti-carcinogenic. However, the anticancer effects of morin and in particular its anti-metastatic effects are not well known. Therefore, in the present study, we investigated the anticancer effects of morin on highly metastatic human breast cancer cells. Our results showed that morin significantly inhibited the colony forming ability of highly metastatic MDA-MB‑231 breast cancer cells from low doses (50 µM) without cytotoxicity. In addition, morin changed MDA-MB‑231 cell morphology from mesenchymal shape to epithelial shape and inhibited the invasion of MDA-MB‑231 cells in a dose-dependent manner. Morin decreased matrix metalloproteinase-9 (MMP-9) secretion and expression of the mesenchymal marker N-cadherin of MDA-MB‑231 cells, suggesting that morin might suppress the EMT process. Furthermore, morin significantly decreased the phosphorylation of Akt, and inhibition of the Akt pathway significantly reduced MDA-MB‑231 invasion. In an in vivo xenograft mouse model, morin suppressed MDA-MB‑231 cancer cell progression. Taken together, our findings suggest that morin exhibits an inhibitory effect on the cancer progression and EMT process of highly metastatic breast cancer cells at least in part through inhibiting Akt activation. This study provides evidence that morin may have anticancer effects against metastatic breast cancer.