Hu T, Gou W, Ren Z, Liu G, Li Y, Zuo D, Hou W
Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Institute of Radiation Medicine, Chinese Academy of Medical Sciences, Tianjin 300192, China.
School of Life Sciences and Biopharmaceutical, Shenyang Pharmaceutical University, Shenyang 110016, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2023 Oct 20;43(10):1665-1673. doi: 10.12122/j.issn.1673-4254.2023.10.03.
To explore the radiosensitizing effect of icaritin on nasopharyngeal carcinoma (NPC) cells and the underlying mechanism.
MTT assay and clonal formation assay were used to evaluate the effect of icaritin on proliferation of human NPC HONE1 and HNE1 cells. The effects of icaritin treatment, γ-ray radiation, or both on production of reactive oxygen species (ROS), cell cycle distribution and apoptosis of the NPC cells were assessed using flow cytometry. The expressions of DNA damage markers γ-H2AX, cycle-related proteins CDC25C, p-CDC25C and cyclin B1, and ferroptosis markers ACSL4 and GXP4 were detected using Western blotting. A nude mouse model bearing subcutaneous HONE1 cell xenograft was used to observe the effect of icaritin and radiation on tumor growth.
Icaritin dose-dependently inhibited the viability of the NPC cells and enhanced the inhibitory effect of radiation on cell proliferation. Flow cytometry and Western blotting showed that icaritin treatment prior to radiation significantly promoted ROS production and γ-H2AX expression in the NPC cells (<0.001). Compared with radiation exposure alone, the combined treatment caused cell cycle arrest in G2 phase, down-regulated CDC25C and cyclin B1 expression, and up-regulated p-CDC25C expression in the cells (<0.01), resulting also in increased cell apoptosis, enhanced expression of ferroptosis protein ACSL4 and lowered expression of GXP4 (<0.001). In the tumor-bearing mice, icaritin treatment, compared with radiation alone, significantly reduced the tumor growth rate and decreased tumor weight (<0.001).
Icaritin can enhance radiosensitivity of NPC cells both and in nude mice possibly by enhancing ROS production to promote iron death of the cells.
探讨淫羊藿素对鼻咽癌（NPC）细胞的放射增敏作用及其潜在机制。
采用MTT法和克隆形成试验评估淫羊藿素对人NPC HONE1和HNE1细胞增殖的影响。运用流式细胞术评估淫羊藿素处理、γ射线辐射或二者联合处理对NPC细胞活性氧（ROS）产生、细胞周期分布及凋亡的影响。采用蛋白质免疫印迹法检测DNA损伤标志物γ-H2AX、细胞周期相关蛋白CDC25C、p-CDC25C和细胞周期蛋白B1，以及铁死亡标志物ACSL4和GXP4的表达。利用携带皮下HONE1细胞异种移植瘤的裸鼠模型观察淫羊藿素和辐射对肿瘤生长的影响。
淫羊藿素剂量依赖性地抑制NPC细胞活力，并增强辐射对细胞增殖的抑制作用。流式细胞术和蛋白质免疫印迹法显示，辐射前用淫羊藿素处理可显著促进NPC细胞中ROS的产生及γ-H2AX的表达（<0.001）。与单独辐射相比，联合处理使细胞周期阻滞于G2期，下调细胞中CDC25C和细胞周期蛋白B1的表达，上调p-CDC25C的表达（<0.01），还导致细胞凋亡增加、铁死亡蛋白ACSL4的表达增强及GXP4的表达降低（<0.001）。在荷瘤小鼠中，与单独辐射相比，淫羊藿素处理显著降低肿瘤生长速率并减轻肿瘤重量（<0.001）。
淫羊藿素可能通过增强ROS产生促进细胞铁死亡，从而在体外和裸鼠体内增强NPC细胞的放射敏感性。
