[Efficacy of 188Re-herceptin radioimmunotherapy in nude mouse model of nasopharyngeal carcinoma].
OBJECTIVE: To evaluate the effect of radioimmunotherapy with (188)Re-labeled herceptin in nude mice bearing nasopharyngeal carcinoma expressing HER2/neu proto-oncogene and explore the feasibility of (188)Re-herceptin for use as a chemical therapeutic and radioimmunotherapeutic agent. METHODS: A direct radiolabeling method was used to prepare (188)Re-Herceptin. Thirty-two nude mice bearing nasopharyngeal carcinoma were randomized into 4 groups (n=8) to receive single intravenous injection of (188)Re-Herceptin, intratumoral injection of (188)Re-Herceptin, (188)Re-nmIgG and (188)Re, respectively, all at the equivalent dose of 11.1 MBq (50 microl). Another 5 tumor-bearing mice received only intratumoral injection of 50 microl normal saline to serve as the control group. Two days after the injections, 3 mice were selected from each group (except for the control group) for biodistribution observation, and the rest mice were monitored for 4 consecutive weeks for tumor volume changes. Pathological examination of the tumor tissues was also performed. RESULTS: The radioactivity uptake in the tumor was significantly greater whereas normal organ uptake significantly lower in the nude mice receiving intratumoral (188)Re-Herceptin injection than in those with intravenous (188)Re-Herceptin injection (11.53%ID/g vs 2.79%ID/g at 48 h). Intratumoral (188)Re-Herceptin injection caused greater inhibition of tumor growth at the 4th week as compared to the intravenous administration. CONCLUSION: Intratumoral (188)Re-Herceptin administration can significantly inhibit the development of nasopharyngeal carcinoma in mice, and may potentially serve as a new clinical option of regional therapy for treating nasopharyngeal carcinoma overexpressing HER2/neu.