Dihydroartemisinin-induced unfolded protein response feedback attenuates ferroptosis via PERK/ATF4/HSPA5 pathway in glioma cells
Authors: Yanjun Mi
Dandan Wang
Liwei Zhang
Xiaofei Zhang
Jinliang Xing
Huan Jin
Wei Du
Zhengzhi Zou
Yucen Song
Qian Ma
Haolong Li
Benxin Hou
Yibing Chen
Journal: Journal of Experimental & Clinical Cancer Research (2019)
Discipline: CLINICAL MEDICINE
Keywords: Dihydroartemisinin; Endoplasmic reticulum stress; Ferroptosis; GPX4; Glioma
Affiliations: Genetic and Prenatal Diagnosis Center, Department of Gynecology and Obstetrics, First Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China., Department of Medical Oncology, Xiamen Cancer Hospital, First Affiliated Hospital of Xiamen University, Xiamen, 361003, China., Department of Medical Oncology, First Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China., Department of Neurosurgery, First Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China., Shandong Medicinal Biotechnology Centre, Key Laboratory for Rare & Uncommon Diseases of Shandong Province, Back and Neck Pain Hospital of Shandong Academy of Medical Sciences, Shandong Academy of Medical Sciences, Jinan, 250062, China., State Key Laboratory of Cancer Biology & Experimental Teaching Center of Basic Medicine, Fourth Military Medical University, Xi'an, 710032, China., Department of General Surgery, Hainan Province Nongken Sanya Hospital, Sanya, 572000, China., MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, Guangdong, China., Department of Neurosurgery, First Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052, China. ., MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, 510631, Guangdong, China. .

Abstract:  Background: Dihydroartemisinin (DHA) has been shown to exert anticancer activity through iron-dependent reactive oxygen species (ROS) generation, which is similar to ferroptosis, a novel form of cell death. However, whether DHA causes ferroptosis in glioma cells and the potential regulatory mechanisms remain unclear. Methods: Effects of DHA on the proliferation, cell death, ROS and lipid ROS generation as well as reduced gluthione consumption were assessed in glioma cells with or without ferroptosis inhibitor. The biological mechanisms by which glioma cells attenuate the pro-ferroptotic effects of DHA were assessed using molecular methods. Results: DHA induced ferroptosis in glioma cells, as characterized by iron-dependent cell death accompanied with ROS generation and lipid peroxidation. However, DHA treatment simultaneously activated a feedback pathway of ferroptosis by increasing the expression of heat shock protein family A (Hsp70) member 5 (HSPA5). Mechanistically, DHA caused endoplasmic reticulum (ER) stress in glioma cells, which resulted in the induction of HSPA5 expression by protein kinase R-like ER kinase (PERK)-upregulated activating transcription factor 4 (ATF4). Subsequent HSPA5 upregulation increased the expression and activity of glutathione peroxidase 4 (GPX4), which neutralized DHA-induced lipid peroxidation and thus protected glioma cells from ferroptosis. Inhibition of the PERK-ATF4-HSPA5-GPX4 pathway using siRNA or small molecules increased DHA sensitivity of glioma cells by increasing ferroptosis both in vitro and in vivo. Conclusions: Collectively, these data suggested that ferroptosis might be a novel anticancer mechanism of DHA in glioma and HSPA5 may serve as a negative regulator of DHA-induced ferroptosis. Therefore, inhibiting the negative feedback pathway would be a promising therapeutic strategy to strengthen the anti-glioma activity of DHA. 

Retracted: No

PubPeer comments:
 Fig. 4B contains two identical FCS plots. I realize that these two identical FCS plots represent the same treatment, however, why the MFI are different? ![file] , 
 Thank your comment. We carefully examined our raw data, and the reason for the slight difference of MFI is that there is a slight difference in the number of cells selected in the two graphs. , 
 #2 Since the cell samples in the two graphs are from the same treatment group in the same experiment, and then the flow cytometry experiments are completed individually in figure4B (a) and (b) , so the graphs are very similar. ,