Targeting Esophageal Squamous Cell Carcinoma by Combining Copper Ionophore Disulfiram and JMJD3/UTX Inhibitor GSK J4

SIMPLE SUMMARY: Targeted therapy for malignant esophageal squamous cell carcinoma (ESCC) remains a big challenge for our clinicians. In an effort to search for the vulnerability of ESCC, we applied a high-throughput drug-screening strategy and found that CuET, a copper chelation product of disulfiram, had a strong synergy effect with the JMJD3/UTX inhibitor GSK J4 in treating ESCC in vitro and in vivo. Interestingly, JMJD3/UTX’s diagnostic and prognostic value, as well as the underlying mechanisms associated with endoplasmic reticulum stress were revealed. Targeting JMJD3 and UTX in combination with disulfiram has the potential to provide a new safe, effective, and available therapy for ESCC. ABSTRACT: The alcohol-averse drug disulfiram has been reported to have anti-tumor effects and is well suited for drug combinations. In order to identify potential drug combinations in esophageal squamous cell carcinoma (ESCC), we screened a bioactive compound library with the disulfiram copper chelation product CuET. The Jumonji domain-containing protein 3 (JMJD3) and the ubiquitously transcribed tetratricopeptide repeat protein X-linked (UTX) inhibitor GSK J4 were identified. To further understand the molecular mechanism underlying the efficient drug combination, we applied quantitative mass spectrometry to analyze the signaling pathway perturbation after drug treatment. The data revealed that the synergistic effect of GSK J4 and CuET was due to the interaction among JMJD3 and UTX, which may play important roles in maintaining endoplasmic reticulum (ER) homeostasis in tumor cells. Interestingly, our clinical data analysis showed that high expression of JMJD3 and UTX was associated with T stage and worse prognosis of ESCC patients, further supporting the importance of the above findings. In conclusion, our findings suggest that the combination of CuET and targeting JMJD3/UTX may be a safe, effective, and available treatment for ESCC.