Affiliation: Research Center for Traditional Chinese Medicine Complexity System, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai 201203, PR China.
Metastasis is the major cause of death in breast cancer patients. In this study, we investigated the effects of baicalin, a natural compound, on cell migration, invasion and metastasis using human breast cancer MDA-MB-231 cell line as model system. Baicalin not only dose-dependently inhibited MDA-MB-231 cells migration and in vitro invasion, but also suppressed the tumor outgrowth and the pulmonary metastasis of MDA-MB-231 cells in xenograft model. Importantly, treatment of baicalin caused little change in body weight, liver and kidney function of recipient animals. Tumorigenesis-inhibitory effect is likely linked to the capability of baicalin to downregulate metalloproteinase (MMP)-2, MMP-9, urokinase-type plasminogen activator (uPA) and uPA receptor (uPAR) expression in MDA-MB-231 cells. As baicalin blocked p38 mitogen-activated protein kinase (MAPK) activity and treatment of p38MAPK inhibitor SB203580 led to the reduction of MMP-2, MMP-9, uPA and uPAR expressions, we concluded that baicalin suppresses the tumorigenecity of MDA-MB-231 cells by down-regulating MMP-2, MMP-9, uPA and uPAR expressions through the interruption of p38MAPK signaling pathway.