( II ) complex as potent radiosensitizer of 125 I through DNA-damage-mediated apoptosis †

Mingjun Bai,‡ Zhaolin Zeng,‡ Li Li, Qiong Wu, *b Yanyang Zhang, Tao Pan, Luwen Mu, a Duo Zhu, Shouhai Guan,* Qiang Xie* and Wenjie Mei b A chiral ruthenium(II) complex, L-[Ru(bpy)2(o-tFMPIP)] (ClO4)2 (o-tFMPIP 1⁄4 20-trifluoromethylphenyl) imidazo [4,5-f][1,10]phenanthroline, was prepared and evaluated for its enhancement of the radiosensitivity of I seeds. The synthetic Ru(II) complex, LR042, effectively enhanced growth inhibition against HepG2 human hepatocellular liver carcinoma cells induced by 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 I seeds vigorously in response to damaged DNA. LR042 improved DNA damage induced by 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 I seed radiotherapy for cancer therapy.