A cyclometalated iridium(III) complex that induces apoptosis in cisplatin-resistant cancer cells

Abstract A novel cyclometalated iridium(III) complex, [Ir(CˆN) 2 (HPIP)]Cl (IrC) was synthesized and characterized. IrC exhibited about 10-fold higher cytotoxicity than cisplatin against A549 cancer cell line. Interestingly, a cisplatin-resistant cell line, A549-CP/R showed sensitivity to IrC. Further study suggested that IrC induced apoptosis via negatively regulated the nuclear factor-kappa B (NF-κB) pathway, which involved reactive oxygen species (ROS) generation, Bcl-2 and caspase family members activation. Taken together, these results suggest that IrC is able to overcome chemoresistance and may be an effective treatment for platinum-resistant cancer therapy.