Tumor-Targeting NHC–Au(I) Complex Induces Immunogenic Cell Death in Hepatocellular Carcinoma

Immunogenic cell death (ICD) is a promising direction of cancer immunotherapy in hepatocellular carcinoma (HCC). A series of novel NHC-Au(I) complexes derived from 4,5-diarylimidazole, containing glycyrrhetinic acid (GA) as an efficient targeting ligand for HCC, were herein designed and synthesized. Among these, complex 4C exhibited excellent effectiveness for tumor targeting and antitumor activity, which induced the occurrence of ICD in HCC cells. Additionally, 4C can effectively inhibit TrxR enzyme activity, increase reactive oxygen species (ROS) expression, lead to redox homeostasis disorder, mediate mitochondrial dysfunction and endoplasmic reticulum stress (ERS), and cause the characteristic discharge of damage-associated molecular patterns (DAMPs) in HCC cells. More importantly, 4C showed a great ICD-inducing effect in a vaccination mouse model and activated antitumor immunity in a tumor-bearing C57BL/6 mouse model, which is consistent with the in vitro results. In conclusion, we found the potential of Au(I) complex with HCC-targeted capability for effective tumor immunotherapy.