中文摘要：

目的：探讨基因联合放疗对小鼠B16移植肿瘤的抑制作用。方法：碱裂解法提取纯化质粒DNA，微量注射法直接将质粒DNA导入体内肿瘤；建立荷瘤小鼠模型，于小鼠右后肢皮下接种5×10^5个B16黑色素瘤细胞，待肿瘤直径达0．3～0．5cm时开始治疗；肿瘤局部注射pNE-mIL-12和pcDNA—B7—1质粒3次，并给予3次X线照射，观察小鼠移植肿瘤的生长情况。结果：pNE-mIL-12重组质粒与pcDNA—B7—1质粒联合2Gy放射治疗组肿瘤生长速率最低，小鼠生存时间明显延长（P〈0．01～P〈0．001），末次照射后31d小鼠死亡率仅为22．2％，而且其中有1只小鼠肿瘤消退。结论：多基因联合放疗可有效抑制小鼠B16移植肿瘤的生长，其效果好于单基因治疗和单纯放疗。

英文摘要：

Objective To study the inhibitory effects of gene combined radiotherapy on mice transplanted with B16 melanoma. Methods Alkaline lysis assay was used to extract and purify the plasmid. Plasmid DNA was injected into tumor by microinjection assay. Mice were inoculated with 5 × 10^5 of B16 melanoma in right hind legs and the therapy was performed when the diameter of tumor reached at 0.3- 0.5 cm. pNE-mIL-12 and pcDNA-B7-1 plasmids were injected locally three times following with irradiation three times. The tumor growth rate of mice was observed. Results The anti-tumor effect of pNE-mIL-12 combined with pcDNA-B7-1 plasmid following with 2 Gy X-ray irradiation was much better than other groups. It showed that the tumor growth rate was slowed, the survival days of mice were delayed significantly （P〈0.01, P〈0. 001）, the death rate of mice 31 d after therapy was only 22.2% and the tumor was deleted in one mouse. Conclusion Multi-genes combined with radiotherapy could inhibit the tumor growth of mice inoculated B16 melanoma and the inhibitory effect is better than single gene therapy and radiotherapy.