Copper ionophore complex ES-Cu synergizes with quercetin to target FDX1, promote cuproptosis, and reverse lenvatinib resistance in hepatocellular carcinoma cells
Lu Yang, Peixian Pi, Mingzhu Zhang, Yutong Jiang, Tiantian Wu, Lijuan Qing, Haibo Wang, Ming Ma, Zhiyu Zhang, Hao Yang, Qiwei Tian, Xiuhong Lu, Gang Huang, Jian Zhao, Beibei Liang
Abstract
INTRODUCTION: Lenvatinib resistance remains a major challenge in hepatocellular carcinoma (HCC) treatment, highlighting the need for novel therapeutic strategies. Cuproptosis, a copper-dependent form of cell death, has been increasingly implicated in cancer progression. Quercetin, a naturally occurring bioactive flavonol known to modulate mitochondrial metabolism and multiple oncogenic signaling pathways, has emerged as a potential sensitizer. OBJECTIVES: This study aimed to elucidate the molecular mechanisms by which lenvatinib-resistant HCC cells evade copper-induced cell death and to evaluate whether quercetin enhances ES-Cu-induced cuproptosis by targeting FDX1 and reprogramming mitochondrial metabolism. METHODS: Integrated methodologies including bioinformatics analysis, clinical specimen profiling, qRT-PCR, cell proliferation assays, intracellular copper quantification, and Western blot were employed to investigate (1) the insensitivityof lenvatinib-resistant hepatocellular carcinoma (HCC) to cuproptosis but target FDX1 can reverse it(2) the potential of quercetin-ES-Cu combinatorial treatment to reverse drug resistance. Furthermore, subcutaneous xenograft models, mitochondrial OCR measurements, mitochondrial enzyme activity/functional assays, and bio-quercetin administration analyses (immunofluorescence, co-immunoprecipitation) were systematically implemented in both in vitro and in vivo settings to delineate the FDX1-mediated cuproptosis activation mechanism and validate therapeutic efficacy. RESULTS: Lenvatinib-resistant HCC cells displayed downregulation of cuproptosis-related genes (FDX1, DLAT) and impaired copper accumulation. Quercetin bind with FDX1, enhanced mitochondrial OCR, and synergistically increased intracellular copper accumulation with ES-Cu, leading to lipoylated protein aggregation, mitochondrial dysfunction, and copper-induced cell death. In vivo, quercetin plus ES-Cu significantly suppressed tumor growth without evident toxicity. CONCLUSION: This study elucidates the mechanisms by which lenvatinib-resistant HCC cells evade cuproptosis, highlighting the therapeutic potential of quercetin and ES-Cu combination treatment as a novel strategy to overcome lenvatinib resistance in HCC.