Abstract
Breast cancer, which is the most frequently diagnosed cancer, is quite heterogeneous. For breast cancer subtypes lacking targeted therapies, it is vitally essential to find novel agents that prevent chemoresistance and metastatic relapse. Flavopereirine is a β-carboline alkaloid that has antiplasmodial activity, and its antiproliferative effect in different cancers remains unclear. The effect of flavopereirine on cell cycle arrest and apoptosis signaling in breast cancer cells was analyzed by flow cytometry. An inhibitor and siRNA were used to confirm the related signaling pathways by Western blot analysis. We found that flavopereirine caused G0/G1 phase arrest in MCF-7 cells and S phase arrest in MDA-MB-231 cells. MDA-MB-231 cells were more sensitive to flavopereirine-induced apoptosis. Furthermore, we found that flavopereirine-induced apoptosis was partially reduced in MDA-MB-231 cells treated with an extracellular regulated kinase (ERK) inhibitor and p38 mitogen-activated protein kinase (MAPK) siRNA. Moreover, p38 siRNA treatment simultaneously reduced phosphorylated ERK expression levels. Conversely, the recovered phosphorylation of AKT decreased the levels of p-ERK and p-p38 MAPK. Overall, flavopereirine induces cell cycle arrest and the AKT/p38 MAPK/ERK signaling pathway, which contribute to flavopereirine-induced apoptosis in MDA-MB-231 cells.