Disulfiram/Copper Combined with Irradiation Induces Immunogenic Cell Death in Melanoma

Immunogenic cell death (ICD) is a programmed pathway leading to cell death and promotion of immunological responses. Melanoma is resistant to chemotherapy and radiotherapy (RT). Disulfiram (DSF), which forms complexes with copper (Cu), has been shown to induce ICD of many tumor types. Here, we aim to investigate whether DSF/Cu combined with irradiation (IR) can induce ICD and exert anti-cancer effects in melanoma. In vitro experiments, treatment of MV3 and B16F10 melanoma cells with DSF/Cu + IR significantly increased the cellular apoptosis and increased ICD markers: damage-associated molecular pattern molecule (DAMP) exposure and release, including calreticulin cell surface expression, high-mobility group box 1 (HMGB1) release, and decreased intracellular ATP levels. In addition, DSF/Cu combined with IR treatment inhibited tumor growth and enhanced tumor-infiltrating immune cells in the B16F10-bearing C57BL/6 model. Our findings reveal that combining IR with DSF/Cu induces ICD and inhibits tumor growth in melanoma, providing a promising strategy to overcome the inherent resistance of RT in melanoma.