Dysregulated Wnt signaling confers resistance to cuproptosis in cancer cells

Cuproptosis is characterized by the aggregation of lipoylated components of the tricarboxylic acid cycle and subsequent loss of iron-sulfur cluster proteins as a unique copper-dependent form of regulated cell death. Dysregulation of copper homeostasis and resulting cuproptosis induction is an emerging area of interest for cancer therapy. However, mechanisms of cancer cell evasion of cuproptosis are not well understood. Here, we found that the cuproptosis process is accompanied by activation of the Wnt/β-catenin pathway. Mechanistically, copper binds to PDK1 and promotes its interaction with AKT, resulting in activation of the Wnt/β-catenin pathway and cancer stem cell (CSC) properties. Notably, aberrant activation of Wnt/β-catenin signaling conferred resistance of CSCs to cuproptosis. Further studies showed that the β-catenin/TCF4 transcriptional complex directly binds to the promoter region of ATP7B, a protein responsible for the efflux of copper ions from the cell, inducing its expression and reducing intracellular copper accumulation, thereby inhibiting cuproptosis. Knockdown of TCF4 or pharmacological blockade of the Wnt/β-catenin pathway increased the sensitivity of CSCs to elesclomol-Cu-induced cuproptosis. These findings reveal a link between copper homeostasis regulated by the Wnt/β-catenin pathway and cuproptosis sensitivity, and may provide a precision medicine strategy for cancer treatment by selectively inducing cuproptosis To comprehensively analyze the changes in transcriptome levels during cuproptosis in cancer cells, Cal27 cells were treated with elesclomol and copper in a 1:1 ratio (elesclomol-Cu, ES-Cu), and the transcriptome was sequenced and analyzed.