Dimethyl Fumarate Mediates Glutathione Metabolism to Drive Cuproptosis and Activate the Antitumor Function of CD8+ T Cells Against Liver Cancer.

Dimethyl fumarate (DMF) exerts cytoprotective effects via antioxidant pathway activation. Whether it modulates antitumor immunity through novel cell death forms remains unclear. GSH/GSSG levels were measured in HCC and adjacent tissues using assay kits, with FDX1 and GCLM expression detected by IHC. Cuproptosis-related proteins (NRF2, FDX1, LIAS) and DLAT oligomerization were assessed by western blotting and immunofluorescence in HCC cells. Intracellular GSH, glutamate, Cu2+, and γ-GCS activity were measured biochemically. Cell viability was determined by CCK-8. CD8+ T cells cocultured with HCC cells were analyzed for GZMB, IFN-γ, and TNF-α by flow cytometry; cytotoxicity was evaluated by LDH release. HCC tissues exhibited elevated GSH, downregulated FDX1, and upregulated GCLM compared with adjacent tissues. Elesclomol-Cu2+ (ES-Cu) induced cuproptosis, upregulating NRF2, downregulating FDX1 and LIAS, promoting DLAT oligomerization, and causing GSH depletion and Cu2+ accumulation; GSH-MEE reversed these effects. DMF inhibited GSH metabolism, evidenced by NRF2 downregulation, decreased GSH, increased GSSG, and suppressed γ-GCS activity. Mechanistically, DMF promoted cuproptosis via NRF2 inhibition, which was reversed by NRF2 overexpression. DMF-induced cuproptosis enhanced TNF-α, IFN-γ, and GZMB expression and increased CD8+ T-cell cytotoxicity; the copper chelator tetrathiomolybdate blocked these effects. DMF induces cuproptosis by modulating GSH metabolism, thereby activating CD8+ T-cell-mediated anti-HCC immunity. This offers potential targets for novel combination therapeutic strategies.