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

A chiral ruthenium(ii) complex, Λ-[Ru(bpy) 2 ( o -tFMPIP)] (ClO 4 ) 2 ( o -tFMPIP = 2'-trifluoromethylphenyl) imidazo [4,5- f ][1,10]phenanthroline, was prepared and evaluated for its enhancement of the radiosensitivity of 125 I seeds. The synthetic Ru(ii) complex, LR042, effectively enhanced growth inhibition against HepG2 human hepatocellular liver carcinoma cells induced by 125 I 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 125 I seeds vigorously in response to damaged DNA. LR042 improved DNA damage induced by 125 I 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 125 I seed radiotherapy for cancer therapy.