Cheng-Cheng Tao, Yue Wu, Xiang Gao, Ling Qiao, Ying Yang, Fang Li, Jie Zou, Yu-Hao Wang, Shu-Yu Zhang, Chang-Long Li, Yuan-Yuan Zhang* and Xiao-Dong Sun* Pages 73 - 85 ( 13 )
<P>Objective: We aim to investigate the anticancer effects and mechanisms of icaritin against breast cancer. </P><P> Materials and Methods: Both estrogen receptor (ER) positive breast cancer cells MCF- 7 and ER-negative MDA-MB-231 cells were employed. We examined the effects of icaritin on the proliferation and migration by wound healing assay and transwell assay. Cell apoptosis and cell cycle of MCF-7 and MDA-MB-231 cells were analyzed using Flow cytometry. Cell autophagy of MCF-7 and MDA-MB-231 cells was assessed by western blotting, acridine orange staining and confocal microscopy. We also detected the expression of apoptosis-related genes by western blotting. In addition, an autophagy inhibitor was used to investigate whether cytoprotective autophagy was induced. Meanwhile, an ER inhibitor was utilized to explore whether ER was involved in autophagy. </P><P> Results: Icaritin inhibited the proliferation and migration, and induced cell cycle arrest of both MDA-MB-231 and MCF-7 cells. Icaritin significantly induced apoptosis of MDA-MB- 231 cells by activating caspase-3. And icaritin stimulated autophagy in MCF-7 cells, as evidenced by increased LC3II/LC3I, enhanced p62 degradation, the accumulation of endogenous LC3 puncta formation, and the increased autophagy flux. Icaritin induced autophagy through upregulating the phosphorylation of AMPK and ULK1. Chloroquine, an autophagy inhibitor, increased icaritin-induced apoptosis and proliferation inhibition of MCF-7 cells. Meanwhile, tamoxifen, an ER inhibitor, reversed icaritin-induced autophagy and proliferation inhibition of MCF-7 cells. </P><P> Conclusion: Our study demonstrated that the antitumor effects of icaritin against breast cancer are related to ER, which suggested that the status of ER should be considered in the clinical application of icaritin.</P>
Icaritin, estrogen receptor (ER), autophagy, apoptosis, AMPK, ULK1.
West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, Department of Neurosurgery and Institute of Neurosurgery, State Key Laboratory of Biotherapy West China Hospital, West China Medical School, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, School of Basic Medicine, Chengdu University of Traditional Chinese Medicine, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, Department of Medical Oncology, Sichuan Cancer Hospital and Institute, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610041, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041, West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu, 610041