From Metal Stress to Regulated Cell Death: An Evidence Framework for Ferroptosis-Cuproptosis Crosstalk in Cancer

Resistance to apoptosis, metabolic plasticity, and redox adaptation are major contributors to cancer progression and treatment failure. Ferroptosis and cuproptosis have therefore emerged as metal-dependent forms of regulated cell-death programs with potential relevance for tumours that survive conventional therapy. Ferroptosis is driven by iron-dependent phospholipid peroxidation when glutathione peroxidase 4 (GPX4)-dependent and parallel antioxidant systems fail, whereas cuproptosis depends on mitochondrial copper engagement of lipoylated tricarboxylic-acid-cycle proteins, lipoylated-protein aggregation, iron-sulfur protein destabilization, and proteotoxic stress. This review integrates the molecular basis, genetic architecture, long non-coding RNA (lncRNA)-mediated regulation, mechanistic crosstalk, and therapeutic implications of ferroptosis and cuproptosis in cancer. It emphasizes a critical evidence hierarchy: expression association, computational signature construction, metal accumulation, reactive oxygen species (ROS) generation, or reduced viability should not be interpreted as pathway dependency without pathway-defining biochemical endpoints and rescue experiments. The most credible translational opportunities will depend on functional stratification, tumour-selective delivery, and pharmacodynamic confirmation that distinguishes pathway-defined ferroptosis or cuproptosis from nonspecific metal-induced and oxidative cytotoxicity.