白介素18和胞嘧啶脱氨酶基因对小鼠肝癌的联合基因治疗

Combined gene therapy for murine liver cancer with interleukin-18 and cytosine deaminase genes

目的 观察白介素18和胞嘧啶脱氨酶基因对小鼠肝癌MM45T.Li联合基因治疗的效果。 方法 将小鼠IL-18基因克隆入pGCEN中，构建成pGCEN/IL-18。包装成逆转录病毒，感染小鼠肝癌细胞MM45T.Li, 制出具有生物活性的MM45T.Li/IL-18瘤苗，灭活后对荷瘤小鼠进行皮下接种。同时利用AdCD/5FC对小鼠肝癌原位注射，进行联合基因治疗。 结果 在接受治疗30d后，MM45T.Li对照组肿瘤体积1580～1625mm3，MM45T.Li/IL-18治疗组（366±159）mm3，AdCD/5FC治疗组（438±65）mm3，IL-18和AdCD/5FC联合治疗组体积（15±7）mm3（P＜0.05）。MM45T.Li对照组中位生存期50.0～51.5d，MM45T.Li/IL-18治疗组65d，AdCD/5FC治疗组57d，联合治疗组76d，和单独治疗组相比，联合治疗组中位生存期明显延长（P＜0.05）。联合基因治疗组肿瘤组织周围有更多CD4+及CD8+淋巴细胞浸润。 结论 IL-18和CD基因的联合治疗组，其疗效要明显好于IL-18或CD基因单独治疗组。进行联合基因治疗，既有效地减少了肿瘤负荷，又充分调动了机体的抗肿瘤免疫，提高了疗效。

Objective To investigate the synergistic antitumor effects of murine IL-18 and CD/5FC gene therapy on mice bearing liver cancer. Methods A retrovirus vector pGCEN/IL-18 containing murine interleukin-18 gene was constructed. The retrovirus carrying IL-18 gene was used to infect murine liver cancer cell MM45T.Li , and proved to secret biological active IL-18. In mice bearing liver cancer, 60Co-irradiated MM45T.Li/IL-18 vaccine was inoculated subcutaneously once a week for two weeks, and/or AdCD was injected intratumorally with 5FC injected i.p. for 8 days. Results Thirty days from the treatment, the tumor volume of control group was 1580~1625mm3, MM45T.Li/IL-18 vaccine group was 366±159mm3, AdCD/5FC group was 438±65mm3, and combined IL-18 and AdCD/ 5FC therapy group was 15±7 mm3(P<0.05). The tumor volume in single gene therapy group reduced to the smallest after three-week treatment, but grew large again, while the tumor volume in combined therapy group still remained small. The median survival time in control group was 50.0~51.5 days, MM45T.Li/IL-18 group was 65 days, AdCD/5FC group was 57 days versus 75 days for combined gene therapy group (P<0.05), and with more abundant infiltration of CD4+ and CD8+ lymphocytes around the tumor in combined gene therapy group. Conclusions Combined gene therapy with IL-18 and CD/5FC can reduce the tumor volume and elicit the antitumor immunity of the host, which is superior to the single gene therapy for murine liver cancer. [