Abstract
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Objectives In this study, we combined 188Re-liposomes with Lipo-Dox in the C26 colon carcinoma peritoneal metastasis mice model to observe therapeutic efficacy.
Methods The 6~8 weeks male BALB/c mice were i.p. inoculation with 2 x 105 C26 cells. BALB/c mice were intravenous (i.v.) administrated with 188Re-liposomes and Lipo-Dox. For the combination therapy, Lipo-Dox was treated at day 4 after tumor inoculation. 188Re-liposomes were treated at day 7. In therapeutic efficacy, the survival time of mice treated with normal saline, 400 μCi 188Re-liposomes, 600 μCi 188Re-liposomes, 2.5 mg/kg Lipo-Dox, combination of 400 μCi 188Re-liposomes with 2.5 mg/kg Lipo-Dox and combination of 600 μCi 188Re-liposomes with 2.5 mg/kg Lipo-Dox were evaluated and compared.
Results In efficacy study, the median survival time for the normal saline control mice was 28.5 d. The increase in lifespan for the mice treated with 400 μCi 188Re-liposomes, 600 μCi 188Re-liposomes and 2.5 mg/kg Lipo-Dox were 24.2%, 86.0% and 75.4%, respectively. However, the group of combination of 400 μCi 188Re-liposomes or 600 μCi 188Re-liposomes with 2.5 mg/kg Lipo-Dox both revealed the longest survival time with the median survival times beyond 120d and the increase in lifespan more than 321%.
Conclusions The results showed that the group of combined 188Re-liposomes with Lipo-Dox attained a longer life span in tumor-bearing mice than that of only chemotherapeutics of Lipo-Dox or radiotherapeutics of 188Re-liposomes. These studies demonstrated that the combination of 188Re-liposomes with Lipo-Dox will enhance the therapeutic effect of 188Re-liposomes. The results presented here establish the potential of combined therapy for treating peritoneal carcinomatosis and provide the ideal therapeutic strategy of 188Re-liposomes in clinical application.