Antioxidants suppress radiation-induced apoptosis via inhibiting MAPK pathway in nasopharyngeal carcinoma cells
Dong‐Fang Meng, Lingling Guo, Li‐Xia Peng, Lisheng Zheng, Ping Xie, Yan Mei, Chang‐Zhi Li, Xing‐Si Peng, Yan‐Hong Lang, Zhi‐Jie Liu, Ming‐Dian Wang, Dehuan Xie, Ditian Shu, Hao Hu, Si‐Ting Lin, Haifeng Li, Fei‐Fei Luo, Rui Sun, Bi‐Jun Huang, Chao‐Nan Qian
Abstract
Nasopharyngeal carcinoma (NPC) is relatively sensitive to ionizing radiation, and radiotherapy is the main treatment modality for non-metastatic NPC. Radiation therapy generates overproduction of reactive oxygen species (ROS), which can cause DNA damage and induce apoptosis in tumors, thereby killing the malignant cells. Although dietary antioxidant supplementation reduces oxidative stress and promotes tumor progression, the effects of antioxidants on the NPC cells upon radiation have not been reported. In the present study, we showed that antioxidants (β-Carotene, NAC, GSH) played an anti-apoptotic role in response to radiation via decreasing ROS production and inhibiting MAPK pathway in NPC cells. Based on that, we conclude that the use of supplemental antioxidants during radiotherapy should be avoided because of the possibility of tumor protection and reduced treatment efficacy.