靶向肝癌细胞自噬提高大黄素的毒性杀伤作用

背景与目的:大黄素处理肝癌细胞后能够诱导内质网应激和凋亡.鉴于内质网应激与自噬之间的关联及后者作为细胞对抗应激环境的一种自我防御机制,该研究拟探讨通过抑制肝癌细胞自噬信号通路的策略提高大黄素对肿瘤细胞的毒性杀伤作用.方法:大黄素处理肝癌细胞后,应用CYTO-ID自噬检测试剂盒和蛋白质]印迹法(Western blot)分别检测大黄素诱发细胞自噬情况;利用细胞自噬抑制剂(氯喹)预先抑制肝癌细胞自噬的产生,然后用大黄素处理肝癌细胞,最后通过ATPlite试验和细胞克隆形成实验检测肿瘤细胞存活;通过流式细胞术检测氯喹和大黄素联合处理诱导肝癌细胞发生凋亡的凋亡率,采用Western blot检测凋亡效应蛋白caspase-3活化断裂后产生活性片段的水平.结果:大黄素处理肝癌细胞后能够诱导肝癌细胞自噬;利用氯喹抑制肝癌细胞自噬能够显著能够提高大黄素对肝癌细胞克隆存活的抑制作用;氯喹和大黄素联合处理肝癌细胞能够显著提高细胞周期sub-G1期和活化caspase-3蛋白的表达水平.结论:靶向肝癌细胞自噬能够提高大黄素的毒性杀伤作用.

Therapeutically targeting autophagy enhances cytotoxicity of emodin in liver cancer cell lines

Background and purpose: The previous work of this study has showed that the treatment of liver cancer cells with emodin could induce endoplasmic reticulum (ER) stress and apoptosis. Given the cross-talk between ER stress and autophagy, this study aimed to investigate whether blockage of autophagy, a defense mechanism against environmental stress, could improve the killing effect of emodin on liver cancer cells. Methods: The CYTO-ID auto-phagy detection kit and Western blot were used to determine autophagy in liver cancer cells. After combined treatment with chloroquine (CQ) and emodin, cancer cell survival was analyzed by ATPlite assay and clonogenic assay. Apoptosis was detected by both flow cytometry analysis and Western blot. Results: Autophagy could be induced in liver cancer cells after treatment with emodin. Inhibition of autophagy significantly increased growth-inhibitory effect of emodin on both HepG2 and Huh7 cancer cells. The combination treatment with CQ and emodin promoted remarkable apoptosis in liver cancer cells, evidenced by the increase in the percentage of cells in sub-G1 phase and the higher expression lever of cleaved caspase-3. Conclusion: Therapeutically targeting autophagy is capable of enhancing cytotoxicity of emodin in liver cancer cell lines.