Schisandrin A inhibits triple negative breast cancer cells by regulating Wnt/ER stress signaling pathway.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer lacking prognostic and effective therapeutic targets currently. In this study, we evaluated the toxic potential of schisandrin A (SchA), a bioactive phytochemical found in Schisandra chinensis in TNBC. The anti-cancer effect and underlying mechanism of SchA on MDA-MB-231 and BT-549 cells were determined in vitro and in xenograft mouse model. Our data show that SchA markedly inhibited the growth of TNBC cells via induction of cell cycle arrest and cell apoptosis. Moreover, over activation of Wnt signaling was observed in TNBC cells, which was significantly suppressed by the treatment of SchA. Also, SchA treatment activated ER stress in TNBC cells. Finally, we verified these inhibitory effects of SchA in the MDA-MB-231 xenograft mouse model. In conclusion, SchA effectively inhibited TNBC in preclinical models by inducing cell cycle arrest and apoptosis via regulating Wnt/ER stress signaling pathway. All of these data indicate that SchA could be a potential candidate for the treatment of TNBC.