Objective: To investigate the expression of Acyl-CoA synthetase long-chain family member 4 (ACSL4) in liver cancer and its role in regulating ferroptosis and proliferation of liver cancer cells.
Methods: Clinical samples of liver cancer and adjacent normal liver tissues were examined for malondialdehyde (MDA) contents and for expressions of mRNA and protein expressions of ACSL4 and proliferating cell nuclear antigen (PCNA) using RT-qPCR and Western blotting. Human liver cancer Huh-7 cells were treated with Erastin (a ferroptosis inducer), Fer-1 (a ferroptosis inhibitor), or both, and the changes in expression levels of MDA, ACSL4 and PCNA were detected, and the cell proliferation was assessed with plate cloning assay.
Results: MDA contents were lower and ACSL4 and PCNA expressions were higher significantly in liver cancer tissues than in adjacent liver tissues. In Huh-7 cells, Erastin treatment significantly inhibited mRNA and protein expressions of ACSL4 and PCNA, suppressed cell proliferation, and increased MDA contents. Fer-1 alone did not produce significant effect on cell viability but reversed the effect of Erastin on ACSL4 and PCNA expressions, cell proliferation and MDA contents.
Conclusion: ACSL4 level is significantly overexpressed in liver cancer. Erastin increases MDA contents and down-regulates ACSL4 expression, thereby promoting ferroptosis and inhibiting proliferation of liver cancer cells, and these effects can be reversed by Fer-1.
目的: 分析酯酰辅酶A合成酶长链家族成员4（ACSL4）在肝癌中的表达，探究铁死亡调控ACSL4对癌细胞增殖能力的影响。
方法: 收集肝癌和癌旁正常肝组织临床样本，HE染色病理学鉴定后，微量法检测丙二醛（MDA）含量，RT-qPCR检测ACSL4与增殖细胞核抗原 （PCNA）的mRNA表达，Western blotting检测ACSL4与PCNA的蛋白表达。体外培养Huh-7人肝癌细胞，先分为3组：即铁死亡诱导剂Erastin组、抑制剂 Fer-1组、以及Erastin 与Fer-1联合作用组；其中Erastin或Fer-1组均包含0、20、40、60、80、100 μmol/L共6个浓度，然后采用筛选的Erastin 浓度80 μmol/L+（0、30、60、90 μmol/L）Fer-1，筛选Fer-1浓度后再分为3组：对照组、80 μmol/L Erastin单独处理组、80 μmol/L Erastin+60 μmol/L Fer-1联合处理组，均作用48 h。干预ACSL4、PCNA的表达后，平板克隆实验检测细胞增殖能力的改变，微量法检测MDA含量的变化。
结果: 相较于癌旁正常肝组织，肝癌组织中MDA含量降低（P<0.01），ACSL4、PCNA的mRNA和蛋白表达均显著增强（P<0.05）；Erastin可抑制ACSL4、PCNA的mRNA和蛋白表达（P<0.01），并抑制细胞增殖（P<0.001）、上调MDA含量（P<0.01）；单独使用Fer-1对细胞存活率无影响；但加入Erastin后再应用Fer-1，则可逆转Erastin对ACSL4、PCNA表达（P<0.05），细胞增殖能力的抑制（P<0.001），MDA含量的上调（P<0.05）。
结论: ACSL4在肝癌中表达增强，Erastin可提高MDA含量、下调ACSL4表达，诱导肝癌细胞铁死亡，抑制癌细胞增殖；Fer-1则可逆转Erastin的上述作用。
Keywords: Acyl-CoA synthetase long-chain family member 4; Erastin; cell proliferation; ferroptosis; liver cancer.