Disulfiram enhances chemotherapeutic effects of doxorubicin liposomes against human hepatocellular carcinoma via activating ROS-induced cell stress response pathways.

PURPOSE: Increasing evidences have revealed the anti-cancer effect of disulfiram. Current disulfiram-based cancer therapies still have limitations, such as poor tumor-targeting ability and insufficient studies on anti-tumor mechanisms.
METHODS: In the present study, tumor-targeting liposomes were prepared as drug carriers to increase retention of disulfiram in tumor cells. Then, anti-tumor efficacy of liposomes and the underlying mechanisms were investigated in in vitro, in vivo, and transcriptomic level.
RESULTS: The results showed that disulfiram enhanced sensitivity of human hepatocellular carcinoma cells to doxorubicin by 15-27-fold, and increased reactive oxygen species (ROS) production as well as caspase-dependent apoptosis. Inhibition of tumor migration and invasion by doxorubicin were further enhanced by disulfiram. In vivo study showed that disulfiram additive doxorubicin liposomes had better performance in suppressing tumor growth than single doxorubicin liposomes. Gene expression profiling found that cellular components destruction, cell stress, check point regulation, and immunoregulation were the main anti-tumor mechanisms of disulfiram. More importantly, disulfiram possessed a great potential to be a protein ubiquitination and murine double minute 4 (MDM4) targeting compound.
CONCLUSIONS: Due to its low price and good safety, it is worth to repurposing disulfiram as a chemotherapeutic drug. Furthermore, MDM4 may act as a biomarker for observation the clinical effect of disulfiram-based treatment.