NG, a novel PABA/NO-based oleanolic acid derivative, induces Human hepatoma cell apoptosis via a ROS/MAPK-dependent mitochondrial pathway
NG, a novel PABA/NO-based oleanolic acid derivative, induces Human hepatoma cell apoptosis via a ROS/MAPK-dependent mitochondrial pathway
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DOI：
10.1016/j.ejphar.2012.07.031
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发表时间：
2012-09-15
影响因子：
5
通讯作者：
Zhang, Yihua
中科院分区：
文献类型：
--
作者：
Liu, Ling;Fu, Junjie;Zhang, Yihua
O-2-（2，4-二硝基-5-{[2-（1,2-烯-28-β-D-吡喃半乳糖基-齐墩果酸-3-基）-氧-2-氧代乙基]氨基}苯基）-1-（N-羟乙基甲氨基）二氮烯-1-鎓-1，2-二醇盐（NG）是一种新的以PABA/NO为基础的油酸衍生物，已被发现在体内和体外均显示出有效的抗肿瘤活性。在本研究中，NG可以显著减小H22实体瘤小鼠模型的肿瘤体积和重量。NG对HepG 2细胞具有选择性的NO生成、细胞毒作用和细胞凋亡作用，而血红蛋白（NO清除剂）可抑制NG的上述作用。此外，NG诱导的HepG 2细胞凋亡的特征是细胞内活性氧（ROS）的产生，线粒体膜电位（Δ psi m）的损失和增加的Bcl-2/Bcl-2比值。同时还检测到线粒体凋亡诱导因子（ALF）和细胞色素c（Cyt c）的释放以及caspase-3、9的激活，表明NG可能通过线粒体介导的途径诱导细胞凋亡。同时，NG处理可导致c-Jun N-末端激酶（JNK）和p38 MAPK的磷酸化激活，但不激活ERK 1/2。发现在NG之前用SP 600125（JNK抑制剂）和SB 203580（p38抑制剂）处理可逆转NG诱导的细胞凋亡。抗氧化剂N-乙酰半胱氨酸（NAC）可阻断NG诱导的细胞凋亡，部分逆转JNK和p38的激活，上调Bax，下调Bcl-2和caspase-3的激活。总之，这些发现表明NO可以从NG释放，其通过ROS/MAPK介导的线粒体途径诱导细胞凋亡。(C)2012爱思唯尔有限公司版权所有。
O-2-(2,4-dinitro-5-{[2-(12-en-28-beta-D- galactopyranosyl-oleanolate-3-yl) -oxy-2-oxoethyl]amino}phenyl)1-(N-hydroxyethylmethylamino)diazen-1-ium-1,2- diolate (NG), a novel PABA/NO-based derivative of oleanolic acid (OA), has been found to show potent antitumor activity both in vivo and in vitro. In the present study, NG could significantly reduce tumor volume and weight in the H22 solid tumor mouse model. Meanwhile, NG showed selective effects on the HepG2 cells including NO generation, cytotoxic effect and apoptosis, which were prevented by hemoglobin (NO scavenger). Moreover, NG-induced apoptosis of HepG2 cells was characteristic of intracellular reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential (Delta psi m) and enhanced Bax-to-Bcl-2 ratio. The release of apoptotic inducing factor (ALF) and cytochrome c (Cyt c) from mitochondria and the activation of caspase-3, 9 were also detected, indicating that NG may induce apoptosis through a mitochondrial-mediated pathway. Simultaneously, NG treatment could lead to the activation of the phosphorylation of c-Jun N-terminal kinase (JNK) and p38 MAPK but not ERK1/2. Treatment with SP600125 (an inhibitor of JNK) and SB203580 (an inhibitor of p38) prior to NG was found to reverse NG-induced apoptosis. Moreover, it was found that antioxidant N-acetylcysteine (NAC) blocked the induction of apoptosis and partly reversed the activation of JNK and p38, up-regulation of Bax, down-regulation of Bcl-2 and the activation of caspase-3 in NG-treated cells. Taking together, these findings suggest that NO can be released from NG, which induces apoptosis through a ROS/MAPK-mediated mitochondrial pathway. (C) 2012 Elsevier B.V. All rights reserved.