Simvastatin inhibits PD-L1 via ILF3 to induce ferroptosis in gastric cancer cells

The treatment of gastric cancer remains challenging, with immunotherapy serving as a critical component of the holistic approach to its treatment. The results of this study indicated that statins could decrease the serum levels of interleukin-enhancing binding factor 3 (ILF3) and programmed cell death ligand 1(PD-L1) in GC patients and improve their prognosis. Functional experiments demonstrated that simvastatin induced ferroptosis by inhibiting ILF3 in GC cells and enhanced the killing effect of activated CD8⁺ T cells on GC cells. The CUT&Tag assay revealed that, mechanistically, simvastatin inhibited ILF3 expression by reducing the acetylation level at residue site H3K14 in ILF3. Next-generation sequencing and Kyoto Encyclopedia of Genes and Genomes analysis revealed that ILF3 regulated PD-L1 expression through the DEPTOR/mTOR signaling pathway. Overall, simvastatin induced ferroptosis in GC cells by inhibiting ILF3 expression while promoting the activation of CD8⁺ T cells to augment antitumor immune responses, thereby facilitating synergistic immunotherapy.