Caspase-3-Dependent Apoptosis of Citreamicin ε-Induced HeLa Cells Is Associated with Reactive Oxygen Species Generation
Caspase-3-Dependent Apoptosis of Citreamicin ε-Induced HeLa Cells Is Associated with Reactive Oxygen Species Generation
复制标题
DOI：
10.1021/tx4000304
复制
发表时间：
2013-07-01
影响因子：
4.1
通讯作者：
Qian, Pei-Yuan
中科院分区：
文献类型：
--
作者：
Liu, Ling-Li;He, Li-Sheng;Qian, Pei-Yuan
柠檬酸霉素是由链霉菌产生的多环口山酮家族的一员，是一种很有前途的抗肿瘤药物。从一种海洋来源的链霉菌中分离出两种非对映体，即桔霉素A（1）和B（2）。这两种非对映异构体的相对构型是使用NMR光谱和成功结晶的西他米星CITREAMINIA（1）确定的。两种非对映体均显示出对HeLa（宫颈癌）和HepG 2（肝癌）细胞的强效细胞毒性活性，IC 50值范围为30至100 nM。末端脱氧核苷酸转移酶dUTP缺口末端标记试验证实，西他霉素A（1）诱导细胞凋亡，Western印迹分析表明，凋亡通过激活caspase-3发生。2，7-二氯荧光素二乙酸酯测定表明，黄霉素可显著增加细胞内活性氧（ROS）浓度。为了证实这一假设，即通过增加细胞内活性氧浓度，西他霉素A（3）和B（4）的氧化产物，氧化西他霉素A（3）和B（4），从一个由Ag 2 O催化的一步反应中获得。这些产物增加细胞内活性氧浓度的能力降低，在HeLa和HepG 2细胞中的细胞毒性与桔霉素e A（1）和B（2）相比显著减弱。
Citreamicins, members of the polycyclic xanthone family, are promising antitumor agents that are produced by Streptomyces species. Two diastereomers, citreamicin epsilon A (1) and B (2), were isolated from a marine-derived Streptomyces species. The relative configurations of these two diastereomers were determined using NMR spectroscopy and successful crystallization of citreamicin epsilon A (1). Both diastereomers showed potent cytotoxic activity against HeLa (cervical cancer) and HepG2 (hepatic carcinoma) cells with IC50 values ranging from 30 to 100 nM. The terminal deoxynucleotidyl transferase dUTP nick-end labeling assay confirmed that citreamicin epsilon A (1) induced cellular apoptosis, and Western blot analysis showed that apoptosis occurred via activation of caspase-3. The 2,7-dichlorofluorescein diacetate assay indicated that citreamicin epsilon substantially increased the intracellular concentration of reactive oxygen species (ROS). To confirm the hypothesis that citreamicin epsilon induced apoptosis through an increase in the intracellular ROS concentration, the oxidized products, oxicitreamicin epsilon A (3) and B (4), were obtained from a one-step reaction catalyzed by Ag2O. These products, with a reduced capacity to increase the intracellular ROS concentration, exhibited a significantly weakened cytotoxicity in both HeLa and HepG2 cells compared with that of citreamicin e A (1) and B (2).