Yang Qingzhuang, Gao Lianghui, Huang Xiaolong, Weng Jie, Chen Youke, Lin Shibu, Yin Qiushi
Department of Hepatobiliary Pancreatic Surgery, First Affiliated Hospital of Hainan Medical University, Haikou, Hainan 570102, P.R. China.
Exp Ther Med. 2021 Sep;22(3):980. doi: 10.3892/etm.2021.10412. Epub 2021 Jul 12.
Sorafenib has been approved as a systemic drug for advanced liver cancer; however, the underlying mechanisms remain unclear. The present study aimed to investigate the effects of sorafenib on the proliferation, autophagy and apoptosis of HepG2 cells under hypoxia. Briefly, reverse transcription-quantitative PCR and western blotting was performed to quantify HIF-1, LC3II/I, mTOR and p70s6K expression levels. Cell proliferation was determined using the Cell Counting Kit-8 assay and the cell apoptosis rate was evaluated using flow cytometry. The results demonstrated that autophagy and apoptosis were induced by hypoxia, and that sorafenib further enhanced hypoxia-induced autophagy and apoptosis in HepG2 cells in a dose-dependent manner. Furthermore, the mechanism of sorafenib-mediated autophagy in liver cancer cell were investigated by using chloroquine (CQ). The results showed that CQ significantly inhibited autophagy by decreasing LC3II/LC3I ratio in HepG2 cells treated with sorafenib and/or hypoxia. By contrast, sorafenib could increase the expression of hypoxia-inducible factor-1 (HIF-1) and of the autophagy marker (LC3II/I) and decrease the expression of mammalian target of rapamycin and p70 ribosomal S6 kinase in HepG2 cells under normoxia and hypoxia conditions, suggesting that sorafenib could induce hypoxia and autophagy in liver cancer cells. In addition, sorafenib was demonstrated to prevent proliferation and induce apoptosis of HepG2 cells under normoxia and hypoxia. Sorafenib could also prevent the malignant behavior of HepG2 by inducing hypoxia and autophagy. In summary, the findings from the present study suggested that sorafenib may inhibit liver cancer progression by activating autophagy and HIF-1 signaling pathway.
索拉非尼已被批准作为晚期肝癌的全身用药；然而，其潜在机制仍不清楚。本研究旨在探讨索拉非尼在缺氧条件下对HepG2细胞增殖、自噬和凋亡的影响。简而言之，采用逆转录定量PCR和蛋白质印迹法检测缺氧诱导因子-1（HIF-1）、微管相关蛋白1轻链3-II/微管相关蛋白1轻链3-I（LC3II/I）、雷帕霉素靶蛋白（mTOR）和p70核糖体蛋白S6激酶（p70s6K）的表达水平。使用细胞计数试剂盒-8检测法测定细胞增殖情况，采用流式细胞术评估细胞凋亡率。结果表明，缺氧可诱导自噬和凋亡，索拉非尼可进一步以剂量依赖的方式增强缺氧诱导的HepG2细胞自噬和凋亡。此外，通过使用氯喹（CQ）研究了索拉非尼介导肝癌细胞自噬的机制。结果显示，CQ可通过降低索拉非尼和/或缺氧处理的HepG2细胞中LC3II/LC3I的比例来显著抑制自噬。相比之下，在常氧和缺氧条件下，索拉非尼均可增加HepG2细胞中HIF-1和自噬标志物（LC3II/I）的表达，并降低mTOR和p70核糖体蛋白S6激酶的表达，提示索拉非尼可诱导肝癌细胞发生缺氧和自噬。此外，索拉非尼在常氧和缺氧条件下均能抑制HepG2细胞增殖并诱导其凋亡。索拉非尼还可通过诱导缺氧和自噬来抑制HepG2细胞的恶性行为。总之，本研究结果提示索拉非尼可能通过激活自噬和HIF-1信号通路来抑制肝癌进展。
