Paris saponin VII promotes ferroptosis to inhibit breast cancer via Nrf2/GPX4 axis

Breast cancer (BC) is one of the malignancies threatening the woman's health. Our study aims to explore the underlying mechanism behind the anti-tumor function of Paris saponin VII (PS VII) in BC. Xenografting experiment was conducted to monitor the tumor growth. The Ki67 and 4-HNE expression were analyzed via immunohistochemical assay. After different treatments, the cell viability, proliferation, invasion, and migration capacity of BC cells were measured by the CCK-8, colony formation, transwell, and wound healing assays, respectively. The ratio of GSH/GSSG was measured by the GSH/GSSG ratio detection assay kit. The lipid ROS and Fe2+ levels were quantified by flow cytometry analysis. The expressions of TFR1, ACSL4, Nrf2, and GPX4 were measured via western blotting. Compared with the Ctrl group, the tumor volumes, and Ki67 expression were markedly reduced in PS VII groups, and the BC cell viability was decreased by PS VII treatment in a dose-dependent manner. The colony numbers, invasive cells, and migration rates were also significantly decreased by PS VII treatment. Then, the Nrf2 as well as GPX4 expressions were decreased and TFR1 expression was increased by PS VII treatment in vitro and in vivo, while there was no difference in ACSL4 expression between Ctrl and PS VII groups. Moreover, the above effects of PS VII could not be observed in GPX4 knockdown cells. PS VII can promote ferroptosis to inhibit BC via the Nrf2/GPX4 axis, which innovatively suggests the pro-ferroptosis effect and therapeutic potential of PS VII in BC.