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目的通过转基因方法观察自杀基因 TK 对小鼠胃癌的杀伤作用,并联合 mIL-2基因,观察免疫反应在增强 TK 杀伤性中的作用.方法应用逆转录病毒方法转导自杀基因 TK,应用脂质体方法转导细胞因子基因 mIL-2.通过体外实验观察 TK 基因对小鼠胃癌 MFC 细胞的杀伤性和旁观者效应;体内实验中首先在615小鼠建立胃癌模型,然后分组将病毒上清注入瘤体内,并结合应用前药和 mIL-2基因,分别观察它们对肿瘤的杀伤作用.通过病理切片观察组织病理变化;应用免疫组化方法观察 T 淋巴细胞亚群在局部的聚集情况.结果 TK 基因在体外即显出明显的杀伤作用,20%的转基因细胞可以杀伤70%～80%以上的肿瘤细胞.体内实验表明 TK基因结合前药 GCV 可显著杀伤肿瘤,而 TK 基因本身并无杀伤作用(P=0.046).联合 mIL-2后抗肿瘤作用进一步加强,部分肿瘤完全消退(P=0.005).免疫组化显示 CD_4~+,CD_8~+细胞在局部聚集.结论自杀基因 TK 联合前药 GCV 对小鼠胃癌产生显著杀伤作用,不仅转基因细胞被杀死,而且通过旁观者效应杀伤大量周围细胞.细胞因子基因 mIL-2可增强 TK 的抗肿瘤作用.
Objective To observe the killing effect of suicide gene TK on gastric cancer in mice by genetically modified method and to observe the effect of immune reaction in enhancing TK cytotoxicity by combining with mIL-2 gene.Methods The retrovirus was used to transduce suicide gene TK, To investigate the cytotoxicity and bystander effect of TK gene on murine gastric cancer cells by in vitro experiments. In vivo experiments, a gastric cancer model was established in 615 mice and then the virus supernatant was injected Tumor and the combination of prodrug and mIL-2 gene were used to observe their killing effect on tumor.The histopathological changes were observed by pathological sections and the local aggregation of T lymphocyte subsets was observed by immunohistochemistry.Results TK Genes in vitro showed significant killing effect, 20% of the transgenic cells can kill more than 70% to 80% of the tumor cells.In vivo experiments show that TK gene combined with the prodrug GCV can significantly kill the tumor, and the TK gene itself has no killing effect (P = 0.046), the anti-tumor effect of mIL-2 was further strengthened, and some of the tumors completely regressed (P = 0.005) .Immunohistochemistry showed that CD_4 ~ + and CD_8 ~ + cells Conclusion Local suicide gene TK combined with prodrug GCV had a significant killing effect on gastric cancer in mice, and not only the transgenic cells were killed, but also a large number of peripheral cells were killed by the bystander effect. The cytokine gene mIL-2 can enhance the anti-tumor effect of TK .