Hou Ya-Qin, Yao Yao, Bao Yong-Li, Song Zhen-Bo, Yang Cheng, Gao Xiu-Li, Zhang Wen-Jing, Sun Lu-Guo, Yu Chun-Lei, Huang Yan-Xin, Wang Guan-Nan, Li Yu-Xin
National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun 130024, China ; Research Center of Agriculture and Medicine Gene Engineering of Ministry of Education, Northeast Normal University, Changchun 130024, China ; Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, China.
National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun 130024, China ; Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, Xuzhou, Jiangsu 221002, China.
Oxid Med Cell Longev. 2016;2016:4941623. doi: 10.1155/2016/4941623. Epub 2015 Nov 22.
Juglanthraquinone C (JC), a naturally occurring anthraquinone extracted from Juglans mandshurica, could induce apoptosis of cancer cells. This study aims to investigate the detailed cytotoxicity mechanism of JC in HepG2 and BEL-7402 cells. The Affymetrix HG-U133 Plus 2.0 arrays were first used to analyze the mRNA expression exposed to JC or DMSO in HepG2 cells. Consistent with the previous results, the data indicated that JC could induce apoptosis and hyperactivated Akt. The Western blot analysis further revealed that Akt, a well-known survival protein, was strongly activated in HepG2 and BEL-7402 cells. Furthermore, an obvious inhibitory effect on JC-induced apoptosis was observed when the Akt levels were decreased, while the overexpression of constitutively active mutant Akt greatly accelerated JC-induced apoptosis. The subsequent results suggested that JC treatment suppressed nuclear localization and increased phosphorylated levels of Foxo3a, and the overexpression of Foxo3a abrogated JC-induced apoptosis. Most importantly, the inactivation of Foxo3a induced by JC further led to an increase of intracellular ROS levels by suppressing ROS scavenging enzymes, and the antioxidant N-acetyl-L-cysteine and catalase successfully decreased JC-induced apoptosis. Collectively, this study demonstrated that JC induced the apoptosis of hepatocellular carcinoma (HCC) cells by activating Akt/Foxo signaling pathway and increasing intracellular ROS levels.
胡桃醌C（JC）是一种从胡桃楸中提取的天然蒽醌，可诱导癌细胞凋亡。本研究旨在探讨JC对HepG2和BEL-7402细胞的详细细胞毒性机制。首先使用Affymetrix HG-U133 Plus 2.0芯片分析HepG2细胞中暴露于JC或二甲基亚砜（DMSO）后的mRNA表达。与之前的结果一致，数据表明JC可诱导细胞凋亡并使Akt过度激活。蛋白质免疫印迹分析进一步显示，Akt是一种著名的存活蛋白，在HepG2和BEL-7402细胞中被强烈激活。此外，当Akt水平降低时，观察到对JC诱导的细胞凋亡有明显的抑制作用，而组成型活性突变体Akt的过表达则大大加速了JC诱导的细胞凋亡。随后的结果表明，JC处理可抑制Foxo3a的核定位并增加其磷酸化水平，而Foxo3a的过表达可消除JC诱导的细胞凋亡。最重要的是，JC诱导的Foxo3a失活通过抑制ROS清除酶进一步导致细胞内ROS水平升高，抗氧化剂N-乙酰-L-半胱氨酸和过氧化氢酶成功降低了JC诱导的细胞凋亡。总的来说，本研究表明JC通过激活Akt/Foxo信号通路并增加细胞内ROS水平来诱导肝癌（HCC）细胞凋亡。
