SERPINE2-mediated activation of JAK2/STAT3 facilitates NRF2 nuclear translocation and GCLC transcription to confer ferroptosis resistance and lenvatinib resistance in hepatocellular carcinoma

BACKGROUND: Acquired resistance remains a major obstacle in molecular-targeted therapy for advanced hepatocellular carcinoma (HCC). This study aimed to elucidate the role and underlying mechanisms of SERPINE2 in mediating lenvatinib resistance by suppressing ferroptosis. METHODS: We analyzed SERPINE2 expression and its clinical prognostic relevance using public databases (TCGA) and clinical samples (tumor tissues and serum) from patients with HCC treated with lenvatinib. By establishing hypoxic and acquired lenvatinib-resistant HCC cell models, combined with subcutaneous xenograft and orthotopic liver cancer mouse models, we systematically evaluated the functional role of SERPINE2 in tumor proliferation, apoptosis, ferroptosis, and lenvatinib resistance in vitro and in vivo. Mechanistic insights were obtained through transcriptome sequencing (RNA-seq), quantitative proteomics, co-immunoprecipitation (Co-IP), nuclear-cytoplasmic fractionation, and measurement of key ferroptosis indicators (lipid ROS, mitochondrial membrane potential, and transmission electron microscopy). Finally, we assessed the therapeutic potential of targeted interventions combining a JAK inhibitor (Ruxolitinib) or NRF2 inhibitor (ML385) with lenvatinib to overcome resistance in vitro and in vivo. RESULTS: SERPINE2 was markedly upregulated in hypoxic and lenvatinib-resistant HCC models and clinical tissues, correlating with a poor prognosis. Mechanistically, SERPINE2 activates the JAK2/STAT3 signaling pathway, promotes the STAT3-NRF2 interaction, and facilitates NRF2 nuclear translocation. This upregulates the antioxidant enzyme GCLC, which strengthens glutathione synthesis, inhibits lipid peroxidation and ferroptosis, and ultimately confers lenvatinib resistance. Inhibiting SERPINE2, STAT3, or GCLC restored ferroptosis and re-sensitized HCC cells to lenvatinib. Furthermore, the combination treatments exhibited significant synergistic antitumor effects in vitro and in vivo. Clinically, elevated SERPINE2 levels positively correlated with GCLC, predicted worse survival outcomes, and effectively distinguished lenvatinib-resistant patients. CONCLUSIONS: This study established the SERPINE2-JAK2/STAT3-NRF2-GCLC signaling axis as a key mechanism driving ferroptosis resistance and lenvatinib treatment failure. Targeting this axis provides a novel therapeutic strategy for overcoming lenvatinib resistance in HCC.