A Cancer-Selective Zinc Ionophore Inspired by the Natural Product Naamidine A

We present data demonstrating the natural product mimic, zinaamidole A (ZNA), is a modulator of metal ion homeostasis causing cancer-selective cell death by specifically inducing cellular Zn(2+)-uptake in transformed cells. ZNA’s cancer selectivity was evaluated using metastatic, patient-derived breast cancer cells, established human breast cancer cell lines, and three-dimensional organoid models derived from normal and transformed mouse mammary glands. Structural analysis of ZNA demonstrated that the compound interacts with zinc through the N(2)-acyl-2-aminoimidazole core. Combination treatment with ZnSO(4) strongly potentiated ZNA’s cancer-specific cell death mechanism, an effect that was not observed with other transition metals. We show that Zn(2+)-dyshomeostasis induced by ZNA is unique and markedly more selective than other known Zn(2+)interacting compounds such as clioquinol. The in vivo bioactivity of ZNA was also assessed and revealed that tumor-bearing mice treated with ZNA had improved survival outcomes. Collectively, these data demonstrate that the N(2)-acyl-2aminoimidazole core of ZNA represents a powerful chemotype to induce cell death in cancer cells concurrently with a disruption in zinc homeostasis.