Ivermectin induces PAK1-mediated cytostatic autophagy in breast cancer.

Ivermectin is a broad-spectrum antiparasitic drug that has recently been demonstrated to exhibit potent anticancer activity against colon cancer, ovarian cancer, melanoma and leukemia. However, the molecular mechanism underlying this anticancer effect remains poorly understood. We recently found that ivermectin markedly inhibits the growth of breast cancer cells by stimulating cytostatic macroautophagy/autophagy in vitro and in vivo. Ivermectin inhibits the AKT-MTOR signaling pathway by promoting ubiquitination-mediated degradation of PAK1 (p21 [RAC1] activated kinase 1), leading to increased autophagic flux. Together, our work unravels the molecular mechanism underpinning ivermectin-induced cytostatic autophagy in breast cancer, and characterizes ivermectin as a potential therapeutic option for breast cancer treatment.