Necroptosis induced by ruthenium (II) complexes as mitochondrial disruptors.

Inducing necroptosis in cancer cells has emerged as an effective strategy to overcome drug resistance. However, while organic small molecules have been extensively studied for this purpose, metal-based compounds have received relatively little attention as triggers of necroptosis. The development of ruthenium (II) hybrid compounds, particularly those containing triazene (Ru-TRZ), highlights a novel avenue for modulating necroptotic cell death. Here we show that incorporating a methyltriazene moiety, a known alkylating warhead, confers superior mitochondrial-targeting properties and enhances cell death compared to amide-containing counterparts. Ru-hybrid TRZ2 exhibits also antitumor efficacy against in vivo drug-resistant cancer cells. Mechanistically, we demonstrate that Ru-TRZ hybrids induce apoptosis. In addition, by activating downstream RIPK3-driven cell death, TRZ2 proficiently restrains normal mitochondrial function and activity, leading to cancer cell necroptosis. Finally, TRZ2 synergizes anti-proliferative activity and cell death effects induced by conventional drugs. In conclusion, Ru-TRZ2 stands as a promising ruthenium-based chemotherapeutic agent inducing necroptosis in drug resistant cancer cells.