青蒿琥酯对白血病K562细胞自噬的影响及其相关机制的研究

Effect of artesunate on autophagy of leukemic K562 cells and its mechanism

目的:研究青蒿琥酯(artesunate,ART)对白血病K562细胞自噬的影响,并初步探讨其作用机制。方法:不同浓度(0、6.25、12.5、25、50、100 mg/L)ART刺激K562细胞,用CCK-8法分别检测24、48、72 h后K562细胞和健康人外周血有核细胞的增殖抑制情况,并计算48 h半数抑制浓度(inhibitory concentration,IC50);IC50浓度下,采用CCK-8法、Annexin V-FITC/PI双染法联合流式细胞仪分别检测空白对照组(未加药物)、10μmol/L自噬抑制剂二磷酸氯喹(chloroquine diphosphate,CQ)组、30 mg/L ART+10μmol/L CQ组及30 mg/L ART组K562细胞的增殖抑制率、凋亡率;Western blot检测不同浓度ART作用K562细胞48 h,及IC50浓度下ART作用K562细胞12、24、48、72 h后,LC3、p62、HMGB1、Beclin1的蛋白表达情况。结果:ART抑制K562细胞增殖,以时间剂量依赖性方式影响,且作用48 h IC50为30 mg/L;30 mg/L ART+10μmol/L CQ组(70.85±5.57)%的增殖抑制率较30 mg/L ART组(34.07±7.32)%、空白对照组(0.00±2.15)%明显增高;Annexin V-FITC/PI双染法联合流式细胞仪结果显示ART+CQ组(16.67±1.34)%的凋亡率较ART(9.48±1.00)%空白对照组(1.92±0.09)%明显增加;Western blot结果显示,与对照组比较,自噬相关分子LC3、p62的蛋白表达水平在所设定的各浓度及不同干预时间时均上调明显。Beclin1的蛋白表达水平在ART高浓度(25、50、100 mg/L)及干预时间(24、48、72 h)较长时下调明显。HMGB1的蛋白表达水平在ART高浓度(50、100 mg/L)及不同干预时间(12、24、48、72 h)时下调明显。结论:ART以时间剂量依赖性方式抑制K562细胞自噬,可能机制是通过抑制自噬体的融合降解、下调自噬形成相关分子HMGB1、Beclin1的表达而减弱肿瘤细胞对恶劣肿瘤微环境的应激反应、扩大肿瘤细胞的损伤,最终促进K562细胞的死亡。

Objective：To study the autophagy of artesunate （ART） on leukemic K562 cells and its possible mechanism. Methods：The inhibitory effect of ART on the proliferation of K562 cells was detected by CCK-8. The cell apoptosis was examined by the flow cy- tometry. Westem blot was carried out to detect the expressions of LC3,p62, HMGB1 and Beclinl. Results：ART inhibited the prolif- eration of K562 cells in a dose-and-time dependent manner, with ICso vahie of 30 mg/L at 48 h. In addition,ART could induce the apoptosis of K562 cells and the apoptosis could incease when combined with CQ. According to the results Western blot,ART could up--regu- late the expressions of autophagy-related molecule LC3,p62 and down-regulate the expressions of HMGB1 ,BeclinL Conclusion ：ART shows the effects in inhibiting the autophagy of leukemic K562 cells. Its mechanism may be related to the down-iegulation the ex-pression of HMGB1 ,Beclin!,and the inhibition of autophagic degradation, and that ART-induced inhibition of autophagy may eventually results in the death in K562 cells.