Knockdown of TIGAR by RNA interference induces apoptosis and autophagy in HepG2 hepatocellular carcinoma cells
Knockdown of TIGAR by RNA interference induces apoptosis and autophagy in HepG2 hepatocellular carcinoma cells
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RNA干扰敲低TIGAR诱导HepG2肝癌细胞凋亡和自噬
DOI：
10.1016/j.bbrc.2013.06.072
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发表时间：
2013-07-26
影响因子：
3.1
通讯作者：
Ge, Shengfang
中科院分区：
文献类型：
--
作者：
Ye, Ling;Zhao, Xiaoping;Ge, Shengfang
细胞凋亡和自噬是调控细胞死亡的重要机制，肝脏中细胞凋亡和自噬之间的关系还有待深入研究。TIGAR（TP 53诱导的糖酵解和凋亡调节因子）是p53诱导的基因，其功能是抑制ROS（活性氧）并保护U2 OS细胞免于经历细胞死亡。在这项研究中，通过RNAi（RNA干扰）沉默HepG 2细胞中的TIGAR下调TIGAR mRNA（类似于75%）和蛋白水平（类似于80%），并导致细胞生长抑制（P <0.01），通过凋亡（P < 0.001）和自噬。我们证明了TIGAR可以增加HepG 2细胞中的ROS水平。TIGAR的下调导致LC-3 II（特异性自噬标记物）的诱导、自噬体的形成和Beclin-1表达的增加。3-MA（3-甲基腺嘌呤），一种自噬螯合阻断剂的抑制剂，抑制TIGAR siRNA增强的自噬，如LC-3 II水平的降低所示。因此，这些数据提供了TIGAR靶向沉默诱导HepG 2细胞凋亡和自噬细胞死亡的第一个证据，我们的数据为TIGAR siRNA在肝细胞癌（HCC）患者中的未来成功应用带来了希望。(C)2013作者爱思唯尔公司出版All rights reserved.
Apoptosis and autophagy are crucial mechanisms regulating cell death, and the relationship between apoptosis and autophagy in the liver has yet to be thoroughly explored. TIGAR (TP53-induced glycolysis and apoptosis regulator), which is a p53-inducible gene, functions in the suppression of ROS (reactive oxygen species) and protects U2OS cells from undergoing cell death. In this study, silencing TIGAR by RNAi (RNA interference) in HepG2 cells down-regulated both TIGAR mRNA (similar to 75%) and protein levels (similar to 80%) and led to the inhibition of cell growth (P < 0.01) by apoptosis (P < 0.001) and autophagy. We demonstrated that TIGAR can increase ROS levels in HepG2 cells. The down-regulation of TIGAR led to the induction of LC-3 II (specific autophagic marker), the formation of the autophagosome, and increased Beclin-1 expression. 3-MA (3-Methyladenine), an inhibitor of autophagic sequestration blocker, inhibited TIGAR siRNA-enhanced autophagy, as indicated by the decrease in LC-3 II levels. Consequently, these data provide the first evidence that targeted silencing of TIGAR induces apoptotic and autophagic cell death in HepG2 cells, and our data raise hope for the future successful application of TIGAR siRNA in patients with hepatocellular carcinoma (HCC). (C) 2013 The Authors. Published by Elsevier Inc. All rights reserved.