Curcumin induces ferroptosis in hepatocellular carcinoma by regulating PERK/Nrf2/HO-1 signaling pathway

Because of the high malignancy and subtle early symptoms of hepatocellular carcinoma (HCC), most patients lose the opportunity for surgery and opt for drug therapy. However, the current drugs for HCC treatment remain suboptimal, underscoring the urgent need to develop a novel anti-HCC agent. Curcumin is a natural chemical compound that has anti-cancer effects on various tumor cells, attracting sustained attention from researchers and clinicians. The present study aims to further elucidate curcumin's anti-HCC mechanisms, thereby offering a promising therapeutic candidate for HCC patients.

The viability of HCC cells was evaluated by Cell Counting Kit-8 (CCK-8) assay. The levels of glutathione (GSH), malondialdehyde (MDA), and total iron in the cells were detected by biochemical kits. The levels of reactive oxygen species (ROS) and Fe²⁺ in the cells were detected by fluorescent probes. The protein expressions of protein kinase RNA-like endoplasmic reticulum kinase (PERK), nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), and glutathione peroxidase 4 (GPX4) in the cells were detected by western blotting.

Curcumin exerted a notably suppressive impact on HCC cells, which could be reversed by ferrostatin-1 (Fer-1) and desferrioxamine (DFO). By detecting cellular metabolic products, we observed an increase in total iron, Fe²⁺, MDA, ROS, and a reduction in GSH levels in HCC cells after treatment with curcumin, and these effects could be attenuated by Fer-1. Western blot analysis showed that curcumin significantly downregulated GPX4 levels in HCC cells while upregulating PERK, Nrf2 and HO-1 expression. Additionally, using PERK inhibitor, HO-1 inhibitor, and endoplasmic reticulum (ER) stress inhibitor could partially reverse the inhibition of HCC cells viability by curcumin and alleviate the reduction of GPX4 expression caused by curcumin.

Curcumin may induce ferroptosis in HCC cells through the PERK/Nrf2/HO-1 signaling pathway, thereby exerting its anti-cancer effects, suggesting that curcumin could potentially be used as a drug for treating HCC.