Abstract

Objective This study investigated the anticancer mechanism of Puerarin, a natural isoflavone, on ferroptosis resistance and immune escape in non-small cell lung cancer (NSCLC) cancer stem cells (CSCs). Methods Cell viability was assessed using the CCK-8 assay after treating A549 (NSCLC) and BEAS-2B (non-cancerous bronchial epithelial) cells with different concentrations of puerarin. To analyze the effects of Puerarin on NSCLC, A549 cells were treated with 50 or 100 μM Puerarin. A549 cells were treated with the inhibitor RU.521 to block the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. Following these interventions, cell proliferation, tumor sphere formation, reactive oxygen species (ROS) production, iron content, lipid peroxidation (LPO), and malondialdehyde (MDA) levels were measured in A549 cells. Isolated human CD8 + T cells were activated and co-cultured with A549 cells to assess cytotoxicity. Results Puerarin concentrations exceeding 10 μM significantly reduced the viability of A549 cells while exhibiting no cytotoxic effects on BEAS-2B cells at concentrations up to 100 μM.Puerarin showed cytotoxic effects in a dose-dependent manner, decreasing the proliferation and CSC traits of A549 cells. Puerarin increased ROS, intracellular iron, LPO, and MDA in A549 cells. Furthermore, Puerarin enhanced CD8 + T cell-mediated cytotoxicity against A549 cells and suppressed their immune escape. Mechanistically, Puerarin activated the cGAS-STING pathway in A549 cells. Inhibition of the cGAS-STING pathway with RU.521 mitigated these anti-cancer effects of Puerarin. Conclusion Puerarin suppresses ferroptosis resistance and immune escape in NSCLC cells by modulating the cGAS-STING pathway.