Research Article

Combination Therapy with Disulfiram, Copper, and Doxorubicin for Osteosarcoma: In Vitro Support for a Novel Drug Repurposing Strategy

Figure 4

Combination treatment of doxorubicin, disulfiram, and copper chloride effectively reduces viability of K7M2 cells and eliminates recovery in vitro. (a) K7M2 OS cells were treated with CuCl2 (0.12–2 μM), Dox (0.02–1.2, 5 μM), Dis (0.5–4 μM), and Dis + CuCl2 (0.12 and 0.25 μM) for 72 hours. After treatment, trypan blue exclusion staining was performed to obtain viable cell counts. Cells were cultured again in fresh media without drugs present and monitored for cellular growth. Dis potentiated with CuCl2 clearly killed the most cells over 72 hours, but all could subsequently recover in culture. (b) Dox and Dis combination treatment also allowed for cellular recovery in vitro, but triple treatment with Dox, Dis, and CuCl2 resulted in over 90% killing over treatment duration and treated cells did not recover after drug removal. Experiments were performed using three independent cell cultures .
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