The superparamagnetic nanoparticles carrying the E1A gene enhance the radiosensitivity of human cervical carcinoma in nude mice.

To explore the effects of early region 1A (E1A) carried by superparamagnetic dextran iron oxide nanoparticles (SDION) on the radiosensitivity of human cervical cancer. The xenograft mice with cervical cancer received weekly intratumoral SDION-E1A injection and a subsequent 50-Gy irradiation. The weekly relative tumor volume and the final tumor volume were compared among different experimental groups. p53 and human epidermal growth factor receptor-2 (HER-2)/Neu expression in final tumor tissue was detected by reverse transcription-PCR and Western blot. The relative tumor volume and the final tissue volume in the SDION-E1A group was significantly smaller than that in Sham and SDION-Vector groups at each time points after irradiation (P < 0.05). Exogenous E1A expression by SDION delivery significantly increased p53 expression, but inhibited HER-2/Neu expression in tumor tissue (P < 0.05). The intratumoral delivery of exogenous E1A carried by SDION increases p53 expression but inhibits HER-2/neu expression, and enhances the radiosensitivity of human cervical cancer in xenograft mice.