二氢青蒿素通过抑制SIRT1的表达而增强5-氟尿嘧啶对胃癌的抗肿瘤活性  

Dihydroartemisinin enhances antitumor effect of 5-fluorouracil against gastric cancer by down-regulating SIRT1 expression

作　　者：万斌[1] 曹恒斌[1] 俞根华[2] 

机构地区：[1]湖州市中心医院药学部,浙江湖州313000 [2]湖州市中心医院放疗介入科,浙江湖州313000

出　　处：《中国病理生理杂志》2017年第12期2195-2201,共7页Chinese Journal of Pathophysiology

摘　　要：目的:探讨二氢青蒿素对5-氟尿嘧啶治疗胃癌的辅助作用并研究其机制。方法:实验分为对照组、二氢青蒿素组、5-氟尿嘧啶组、5-氟尿嘧啶联合二氢青蒿素组和5-氟尿嘧啶+二氢青蒿素+SIRT1质粒组。MTT法检测胃癌细胞系BGC-823在5-氟尿嘧啶联合二氢青蒿素处理下的细胞活力。Western blot实验检测5-氟尿嘧啶联合二氢青蒿素对BGC-823细胞SIRT1和NADPH氧化酶表达水平,caspase-9和caspase-3活化水平及凋亡信号调节激酶1(ASK1)和c-Jun氨基末端激酶(JNK)蛋白磷酸化水平的影响。流式细胞术检测BGC-823细胞在5-氟尿嘧啶和二氢青蒿素联合处理下的活性氧簇(ROS)生成水平和细胞凋亡率。结果:二氢青蒿素处理能显著抑制BGC-823细胞SIRT1的表达并增加NADPH氧化酶的蛋白水平,明显提高BGC-823细胞对5-氟尿嘧啶的敏感性,降低5-氟尿嘧啶的半数抑制浓度;转染SIRT1表达质粒后,二氢青蒿素联合5-氟尿嘧啶对BGC-823细胞的杀伤活性受到显著抑制(P<0.05)。二氢青蒿素能明显促进5-氟尿嘧啶对BGC-823细胞生成ROS的诱导效应和ASK1及JNK的磷酸化(P<0.05)。用ROS清除剂N-乙酰半胱氨酸(NAC)或JNK特异性抑制剂SP600125处理后,二氢青蒿素联合5-氟尿嘧啶对BGC-823细胞的杀伤活性和caspase-9及caspase-3的活化均受到明显抑制(P<0.05)。另外,NAC能显著抑制二氢青蒿素联合5-氟尿嘧啶对JNK磷酸化的促进作用,而SP600125却不能影响BGC-823细胞ROS的产生,表明JNK是ROS的下游分子。结论:二氢青蒿素联合5-氟尿嘧啶通过SIRT1/NADPH氧化酶/ROS/JNK通路诱导胃癌细胞发生caspase依赖的凋亡。AIM： To investigate the effect of dihydroartemisinin （ DHA） adjuvant treatment on enhancing the antitumor effect of 5-fluorouracil （5-FU） against gastric cancer. METHODS： The gastric cancer BGC-823 cells were di-vided into control group, DHA group, 5-FU group, 5-FU ＋ DHA group and 5-FU ＋ DHA ＋ SIRT1 plasmid group. The via-bility of BGC-823 cells treated with DHA and 5-FU was measured by MTT assay. The expression of SIRT1 and NADPH ox-idase, activation of caspase-9 and caspase-3, and phosphorylation of ASK1 and JNK in the BGC-823 cells treated with DHA and 5-FU were determined by Western blot. The production of ROS and the apoptosis of the BGC-823 cells treated with DHA and 5-FU were analyzed by flow cytometry. RESULTS ： Dihydroartemisinin significantly inhibited the expression of SIRT1 and increased NADPH oxidase protein level （P 〈0. 05 ） . DHA increased the sensitivity of BGC-823 cells to 5- FU, thus decreasing the IC50 of 5-FU to the gastric cancer cells. However, transfection with SIRT1 plasmid decreased the cytotoxicity of DHA and 5-FU co-treatment to the BGC-823 cells. DHA promoted the production of ROS and phosphoryla-tion of ASK1 and JNK induced by 5-FU in the BGC-823 cells （P 〈0.05）. However, ROS scavenger acetylcysteine （NAC） or JNK specific inhibitor SP600125 inhibited the cell death and activation of caspase-9 and caspase-3 induced by DHA and 5-FU co-treatment （P 〈 0. 05） . In addition, NAC significantly inhibited the phosphorylation of JNK in the BGC- 823 cells co-treated with DHA and 5-FU. However, treatment with SP600125 did not influence the ROS production in the BGC-823 cells, indicating that JNK was the downstream target of ROS pathway. CONCLUSION： Combination of DHA with 5-FU induces caspase-dependent apoptosis in gastric cancer cells through the SIRT1/NADPH oxidase/ROS/JNK sig-naling pathway.

关 键 词：二氢青蒿素 SIRT1蛋白 5-氟尿嘧啶 BGC-823细胞 活性氧簇 JNK信号通路 

分 类 号：R0[医药卫生] R285.5