Chiral ruthenium(ii) complex as potent radiosensitizer of I-125 through DNA-damage-mediated apoptosis

A chiral ruthenium(ii) complex, -[Ru(bpy)(2)(o-tFMPIP)] (ClO4)(2) (o-tFMPIP = 2-trifluoromethylphenyl) imidazo [4,5-f][1,10]phenanthroline, was prepared and evaluated for its enhancement of the radiosensitivity of I-125 seeds. The synthetic Ru(ii) complex, LR042, effectively enhanced growth inhibition against HepG2 human hepatocellular liver carcinoma cells induced by I-125 seeds and consequently effectively promoted the apoptosis of tumor cells with increasing level of cleave-caspase-3. Furthermore, the results of immunofluorescence indicated that LR042 enhanced the phosphorylation of H2AX by I-125 seeds vigorously in response to damaged DNA. LR042 improved DNA damage induced by I-125 seeds, which resulted in apoptosis through the activation of the p53/AKT signal. In conclusion, synthetic LR042 can be further developed as a potential radiosensitizer of I-125 seed radiotherapy for cancer therapy.