IL-18基因修饰小鼠CT26结肠癌细胞体内外生物学特性

目的 观察腺病毒介导IL-18基因修饰的小鼠CT26结肠癌细胞体内外的生物学特性。方法 采用ELISA法检测细胞因子，MTT法检测细胞的增殖反应能力，^51Cr释放法检测脾细胞的NK活性及CTL杀伤活性。结果 IL-18基因修饰的CT26细胞能够在转染后4小时即可分泌IL-18，48小时达到高峰，96小时后开始下降。IL-18基因转染对CT26在体外培养过程中的增殖与形态没有明显的影响。IL-18基因修饰的CT26细胞与野生型的CT26细胞和LacZ转染的CT26细胞相比，在体内的致瘤性明显降低，平均生存期延长。IL-18基因修饰的CT26细胞在体内的抗肿瘤免疫反应与IL-18活化NK细胞和CTL细胞的杀伤活性有关。结论 IL-18基因修饰的肿瘤细胞能够激发机体的抗肿瘤免疫反应，但不足以完全抑制肿瘤细胞的生长，还需要与其他因素联合才能够有效地清除肿瘤细胞。

The biological characteristics of IL-18 gene-modified murine colorectal adenocarcinoma cell CT26 in vivo and in vitro

Objective: To observe the biological characteristics of adenovirus-mediated IL-18 gene-modified murine colorectal adenocarcinoma cell CT26 in vivo and in vitro. Methods: The cytokines were assayed by ELISA. Proliferation of the cells was determined by MTT. The cytotoxicity of NK and CTL was detected by 4h 51 Cr releasing assay. Results: The levels of IL-18 could be detected at 4h after CT26 were transfected by IL-18, reached the peak at the 48h, maintained for 96h, and then went down. The morphology and proliferation of IL-18 gene-modified CT26 cells showed no difference from those of wild-type CT26 cells. The tumorigenicity of the IL-18 gene-modified CT26 cells was obviously decreased and the mean survival time was obviously longer compared with that of the wild-type group or the LacZ-transfected CT26 cells. The antitumor immunity of the mice induced by the IL-18 gene-modified CT26 cells was consistent with the elevation of the activity of NK cells and the cytotoxicity of CTL. Conclusion: IL-18 gene-modified tumor cells can induce the antitumor immune responses incompletely, but only inhibit the growth of tumor cells ,thus other factors are reguired for effective antitumor response.