24-Dehydrocholesterol Reductase Facilitates Cisplatin Resistance of Non-small Cell Lung Cancer via Repressing Reactive Oxygen Species/Ferroptosis Pathway.

BACKGROUND: Non-small-cell lung cancer (NSCLC) remains a deadly malignancy worldwide. Resistance to cisplatin (DDP) is a significant obstacle that limits the therapeutic efficacy in NSCLC patients. OBJECTIVES: This study investigated the role and mechanism of 24-dehydrocholesterol reductase (DHCR24) in DDP resistance in NSCLC cells. METHODS: 24-dehydrocholesterol reductase levels, ferroptosis-related molecules, and proteins involved in the PI3K/AKT/GSK3β pathway were measured. The growth capacity of the cells was evaluated, and ferroptosis was assessed by measuring MDA, GSH, Fe(2+), and ROS levels. The impact of DHCR24 on NSCLC DDP resistance was analyzed using a tumor xenograft assay in vivo. Ki-67 and DHCR24 expression in tumors were evaluated through immunohistochemical staining. RESULTS: 24-dehydrocholesterol reductase expression was elevated in DDP-resistant cells, indicating a poorer prognosis for NSCLC patients. Down-regulation of DHCR24 inhibited the growth of DDP-resistant cells and induced ferroptosis. Inhibition of DHCR24 led to the inactivation of the PI3K/AKT/GSK3β pathway and subsequent induction of ferroptosis. Inhibition of ferroptosis or activation of the PI3K/AKT/GSK3β pathway counteracted the increased DDP sensitivity induced by DHCR24 knockdown in NSCLC cells. Additionally, DHCR24 deficiency improved NSCLC DDP resistance in vivo. CONCLUSIONS: 24-dehydrocholesterol reductase contributes to DDP resistance in NSCLC cells by suppressing ferroptosis through the activation of the PI3K/AKT/GSK3β pathway.