人COX-2基因反义真核表达载体对胃癌转移的影响

Effect of COX-2 gene antisense eukaryotic expression vector on SGC-7901 metastasis

目的：在成功构建人COX-2基因反义真核表达载体的基础上,研究COX-2基因对人胃癌细胞株SGC-7901转移能力的影响。方法：实验分为COX-2基因反义真核表达载体转染的人胃癌细胞株SGC-7901转染组、COX-2抑制剂SC236处理组（SGC-7901细胞培养基内含100μmol/L SC236）和对照组（SGC-7901细胞）,并分别采用细胞体外侵袭实验,内皮细胞体外迁移实验,观察各组细胞体外转移的情况。采用裸鼠皮下移植瘤抑制实验,用转染和未转染的SGC-7901细胞按每毫升5×10~7个的细胞悬液分别注射于BALB/C-nu/nu无胸腺裸鼠背部皮下,SC236处理组按3mg/（kg·d）剂量于接种SCC-7901细胞10min后,由尾静脉注射,隔日1次。各组6周后处死动物,观察皮下移植瘤的生长情况。并用Western blot法检测各组细胞VEGF及MMP-2蛋白的表达。结果：体外侵袭实验、促内皮细胞体外迁移实验结果显示,与对照组相比,转染组和SC236处理组迁移的肿瘤细胞和内皮细胞均减少（P〈0.01）;裸鼠皮下移植抑制实验结果显示,转染组和SC236处理组荷瘤鼠移植瘤的生长受到抑制;Western blot结果显示,转染组和SC236处理组细胞VEGF及MMP-2蛋白的表达下降。结论：反义COX-2基因能抑制SCG-7901细胞的转移能力,其机制可能与其抑制肿瘤的血管生成、减少MMP-2的表达有关。

OBJECTIVE：Use constructed antisense expression vector of human COX-2 gene and observe the relationship between COX-2 gene and tumor metastasis.METHODS：Gastric cancer cell line SCG-7901 was transfected with antisense expression vector of human COX-2 gene.Three groups of cells which included transfectant、SC236 treated group（SCG-7901 treated with COX-2 inhibitor SC236 at 100μmol/L） and SCG-7901 as a control group.Changes of the invasion ability in each group were observed in vitro.Western blot was used to detect VEGF and MMP-2 expressions in the 3 groups.Then the transfectant and SCG-7901 were injected subcutaneously into BALB/Cnu /nu nude mice to develop transplantation tumor,another group of mice received SCG-7901 treated with SC236 injected subcutaneously.The sizes and the weights of the lesions were observed.RESULTS：The results of transwell membrane、cell migration and the growth of transplanted tumors showed that after transfection the invasion ability of SCG-7901 was obviously inhibited,the expressions of VEGF and MMP-2 in the cell line decreased.CONCLUSION：Transfection with antisense expression vector of human COX-2 gene had obvious antitumor activity on metastasis of human gastric cancer cell line in nude mice.The mechanism may be via inhibition of angiogenesis and down-regulation of MMP-2 expression.