Zhang Xin, Xu Lan, Yang Ting
Department of Laboratory, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, Liaoning 110042, People's Republic of China.
Onco Targets Ther. 2020 Jan 29;13:877-888. doi: 10.2147/OTT.S227467. eCollection 2020.
Liver cancer is one of the most common malignant tumor in the world. miR-31 is downregulated in liver cancer and associated with tumor growth and metastasis. However, the underlying mechanism remains unclear.
Cellular apoptosis was detected via MTT, TUNEL assay, LDH release and Annexin V/PI flow-cytometry analysis. Cellular migration and invasion were measured by the Transwell chamber assay. Mitochondrial functions were evaluated via mitochondrial membrane potential JC-1 staining and mPTP opening assessment. The mitophagy activity was examined via Western blots.
In the present study, our results confirm that miR-31 promotes apoptosis and inhibits proliferation and metastasis in liver cancer HepG2 cells. In vitro, miR-31 promotes HepG2 cell apoptosis through the mitochondrial pathway as indicated by mitochondrial potential reduction, increased mPTP opening time, cty-c release and imbalance of pro- and anti-apoptotic proteins. Furthermore, miR-31 reduces the energy generation by inhibiting mitochondrial respiratory function. At last, it is demonstrated that miR-31 triggers the mitochondrial damage via ROCK1/F-actin pathway. Inhibiting the ROCK1/F-actin pathway abolishes the effects of miR-31 mimic on mitochondrial injury, apoptosis, proliferation arrest and migration inhibition.
Our results reveal that miR-31 can inhibit HepG2 cell survival and metastasis by activating the ROCK1/F-actin pathway.
肝癌是世界上最常见的恶性肿瘤之一。miR-31在肝癌中表达下调，并与肿瘤生长和转移相关。然而，其潜在机制仍不清楚。
通过MTT法、TUNEL检测、LDH释放及Annexin V/PI流式细胞术分析检测细胞凋亡。采用Transwell小室检测法测定细胞迁移和侵袭能力。通过线粒体膜电位JC-1染色和mPTP开放评估来评价线粒体功能。通过蛋白质免疫印迹法检测线粒体自噬活性。
在本研究中，我们的结果证实miR-31可促进肝癌HepG2细胞凋亡，并抑制其增殖和转移。在体外，miR-31通过线粒体途径促进HepG2细胞凋亡，表现为线粒体电位降低、mPTP开放时间增加、细胞色素c释放以及促凋亡蛋白和抗凋亡蛋白失衡。此外，miR-31通过抑制线粒体呼吸功能减少能量生成。最后，证明miR-31通过ROCK1/F-肌动蛋白途径引发线粒体损伤。抑制ROCK1/F-肌动蛋白途径可消除miR-31模拟物对线粒体损伤、凋亡、增殖阻滞和迁移抑制的影响。
我们的结果表明，miR-31可通过激活ROCK1/F-肌动蛋白途径抑制HepG2细胞存活和转移。
