Department of Hepatobiliary and Pancreatic Surgery, the First Hospital of Jilin University, Changchun, Jilin, 130021, China.
Tumor Biotherapy Center, Jilin Province People's Hospital, Changchun, Jilin, 130021, China; Laboratory Center, the First Hospital of Jilin University, Changchun, Jilin, 130021, China.
Arch Biochem Biophys. 2020 Aug 15;689:108415. doi: 10.1016/j.abb.2020.108415. Epub 2020 Jun 17.
Regorafenib, a multiple kinase inhibitor, is recently approved for treatment of patients with advanced hepatocellular carcinoma (HCC). Previous studies demonstrated that regorafenib was a mitochondrial toxicant, which associated with the impairment of mitochondria. Sirt3 is involved in the regulation of mitochondrial function in cancers. This study aimed to investigate the mechanism of Sirt3 involved in the mitochondrial dysfunction which associated with regorafenib treatment in liver cancer cells. We found regorafenib inhibited Sirt3 and p-ERK expression in HCC cells in a dose-dependent manner. Bioinformatics analysis showed that Sirt3 expression was down-regulated in liver cancer tissues and its low expression was correlated with worse overall survival (OS) in liver cancer patients. After transfected with Sirt3 overexpression plasmid, we found that Sirt3 sensitized liver cancer cells to regorafenib and resulted in much more apoptosis with a significant increase of ROS level. However, exogenous antioxidant could not weaken the apoptosis. Mitochondrial membrane potential assay indicated that Sirt3 overexpression accelerated the mitochondrial depolarization process induced by regorafenib and aggravated mitochondrial injury. Cellular oxygen consumption assay showed that mitochondrial dysfunction was caused by the damage of the electron transport chain. The results demonstrated that Sirt3 overexpression promoted the increase of ROS and apoptosis induced by regorafenib through the acceleration of mitochondrial dysfunction by impairing function of the electron transport chain in liver cancer cells. Our studies verified the functional role of Sirt3 in regorafenib treatment and suggested that regorafenib accompanied with Sirt3 activator as a novel treatment strategy for HCC.
瑞戈非尼是一种多激酶抑制剂，最近被批准用于治疗晚期肝细胞癌（HCC）患者。先前的研究表明，瑞戈非尼是一种线粒体毒物，与线粒体功能障碍有关。Sirt3 参与癌症中线粒体功能的调节。本研究旨在探讨 Sirt3 参与瑞戈非尼治疗肝癌细胞中线粒体功能障碍的机制。我们发现瑞戈非尼以剂量依赖的方式抑制 HCC 细胞中的 Sirt3 和 p-ERK 表达。生物信息学分析表明，Sirt3 在肝癌组织中表达下调，其低表达与肝癌患者的总生存期（OS）较差相关。转染 Sirt3 过表达质粒后，我们发现 Sirt3 使肝癌细胞对瑞戈非尼敏感，导致更多的细胞凋亡，ROS 水平显著升高。然而，外源性抗氧化剂不能减弱细胞凋亡。线粒体膜电位测定表明，Sirt3 过表达加速了瑞戈非尼诱导的线粒体去极化过程，并加重了线粒体损伤。细胞耗氧率测定表明，线粒体功能障碍是由电子传递链损伤引起的。结果表明，Sirt3 过表达通过损害电子传递链的功能加速了瑞戈非尼诱导的 ROS 和细胞凋亡的增加，从而导致线粒体功能障碍。我们的研究验证了 Sirt3 在瑞戈非尼治疗中的功能作用，并表明瑞戈非尼联合 Sirt3 激活剂可能成为 HCC 的一种新的治疗策略。
