SLC16A3 Drives Lung Adenocarcinoma Progression and Gefitinib Resistance through Coordinated Regulation of Ferroptosis and Lactate Metabolism

Background Ferroptosis is an iron-dependent form of regulated cell death that plays a critical role in tumor suppression and therapy response. However, the metabolic mechanisms that drive ferroptosis resistance in lung adenocarcinoma (LUAD), particularly in the context of EGFR-TKI tolerance, remain unclear. Methods We integrated transcriptomic and clinical data from the TCGA LUAD cohort and performed survival and enrichment analyses. Functional assays including proliferation, invasion, ferroptosis indicators, and in vivo xenograft models were used to evaluate the role of SLC16A3. Lactate rescue, transcription factor prediction (JASPAR), mIHC, and luciferase reporter assays were applied to dissect regulatory mechanisms. Pharmacological inhibition of SLC16A3 was used to assess therapeutic potential. Results SLC16A3 expression was elevated in LUAD and correlated with poor prognosis. Knockdown of SLC16A3 suppressed tumor cell growth and enhanced ferroptosis, as indicated by increased lipid peroxidation, iron accumulation, and mitochondrial depolarization. Lactate supplementation partially reversed ferroptosis induction. Mechanistically, SLC16A3 was transcriptionally activated by HIF1A, and the HIF1A-SLC16A3 axis conferred ferroptosis resistance and gefitinib tolerance. In vivo, SLC16A3 inhibition restored ferroptotic sensitivity and enhanced EGFR-TKI efficacy in xenograft models. Conclusion Our findings reveal that the HIF1A-SLC16A3-lactate axis orchestrates ferroptosis suppression and therapeutic resistance in LUAD. Targeting SLC16A3 represents a promising metabolic strategy to overcome EGFR-TKI resistance by reactivating ferroptosis.