Rhamnazin Inhibits Hepatocellular Carcinoma Cell Aggressiveness in Vitro via Glutathione Peroxidase 4-Dependent Ferroptosis.

Ferroptosis, a newly recognized type of programmed cell death, is characterized by lipid peroxidation and implicated in multiple pathophysiological processes. Ferroptosis agonists are attracting tremendous attention for the clinical management of malignancy. We uncovered that rhamnazin exerted its anti-cancer property via reducing cell proliferation and invasion in hepatocellular carcinoma (HCC) cells. The ferroptosis inhibitor ferrostatin-1 (Fer-1) partially reversed rhamnazin-triggered cell proliferation inhibition, indicating that ferroptosis contributed to the inhibitory potency of rhamnazin. Further characterization corroborated that exposure with rhamnazin, reactive oxygen species (ROS) accumulation and lipid peroxidation, and iron content were elevated in HCC cells. Mechanistically, we demonstrated that glutathione peroxidase 4 (GPX4) was involved in rhamnazin-initiated ferroptotic cell death. Overexpression of GPX4 weakened HCC cell ferroptosis caused by rhamnazin. Collectively, these results strongly suggest that rhamnazin exerts a ferroptosis-inducing role in HCC cells by inhibiting GPX4 expression.