Abstract
Licochalcone A (LicoA) possesses anti-tumor properties. However, the potential therapeutic effect of LicoA on uterine leiomyomas (ULs) remains unknown. In this study, the effects of LicoA on the proliferation of ULs and its underlying mechanism were explored. LicoA treatment significantly decreased the viability of uterine smooth muscle cells (UtSMCs) and ELT3 cells in a dose-dependent manner. The induction of ELT3 cell apoptosis by LicoA was accompanied by the increased generation of reactive oxygen species (ROS), elevated endoplasmic reticulum (ER) stress (GRP78/IRE1α/ATF6/CHOP), and the increased expression of proapoptotic proteins (c-caspase-3, c-caspase-9, and c-PARP). The ability of Z-VAD-FMK (a caspase inhibitor) and n-acetylcysteine (NAC; a cell membrane permeable antioxidant) to reverse LicoA-induced ROS-mediated ER stress pathways also observed. Furthermore, GRP78 or JNK knockdown was involved in LicoA-induced ROS-mediated ER stress and apoptosis in ELT3 cells. In immunodeficient mice, LicoA significantly suppressed the growth of ELT3 tumor cells, without toxicity. This study is the first to show that LicoA exerts anti-leiomyoma effects via the modulation of ROS-mediated ER stress-induced apoptosis through the JNK/GRP78/NRF2 signaling pathway.