[Ferroptosis inducer Erastin inhibits proliferation of liver cancer cells in vitro by downregulating ACSL4].

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.