环氧合酶-2反义核酸抑制胃癌细胞的恶性表型

目的　通过环氧合酶 2 (COX 2 )反义核酸基因转染 ,逆转COX 2高表达的人胃癌细胞系中其表达水平 ,观察细胞生物学行为的变化情况 ,以初步探讨COX 2表达在胃癌发生中的某些具体机制。方法　使用脂质体介导的方法 ,用反义重组质粒及空载体分别转染COX 2异常高表达的人胃癌细胞系SGC 790 1(转染细胞分别命名为 790 1 AS及 790 1 P细胞 )。通过免疫细胞化学及RNA斑点杂交试验检测反义核酸转染的细胞中COX 2的蛋白及mRNA表达水平。四唑盐 (MTT)比色试验检测转染细胞的体外增殖速度。应用裸鼠成瘤试验比较转染前后细胞体内成瘤能力的差别。结果　免疫细胞化学及RNA斑点杂交试验证实 :在反义核酸转染的 790 1 AS细胞中COX 2的蛋白及mRNA水平均显著下调。MTT比色试验显示 790 1 AS细胞的增殖速度低于亲本SGC 790 1细胞。裸鼠成瘤试验表明 ,反义核酸转染细胞成瘤潜伏期延长 ,成瘤体积减小。 3组细胞接种裸鼠 30d后 ,瘤体的平均重量( x±s)分别为 (82 6 6 7± 77 6 7)mg(SGC 790 1细胞 ) ,(776 6 7± 30 0 0 6 )mg(790 1 P细胞 )和 (486 6 7±15 2 8)mg (790 1 AS细胞 )。转染反义核酸的细胞成瘤性显著低于未转染细胞及转染载体对照细胞(P <0 0 1)。结论　胃癌细胞中过表达的COX 2与细胞的恶性表型相关。用

Antisense inhibition of cyclooxygenase-2 reduces malignant phenotype of gastric cancer cells

OBJECTIVE: To investigate the role of cyclooxygenase-2 (COX-2) in tumorigenesis of gastric cancer, and the introduction of into human gastric cancer cells to suppress COX-2 expression. METHODS: The high COX-2 expressing human gastric cancer cell line SGC 7901 was stably transfected with the COX-2 antisense recombinant vector and plain vector (named as 7901-AS and 7901-P cells). The COX-2 expression levels in transfected cells were detected by immunocytochemistry and dot blotting methods. Proliferation and tumorigenic ability of transfected (7901-AS, 7901-P) and control (SGC 7901) cells were evaluated in vitro with MTT assay and in vivo with nude mice. RESULTS: Antisense treatment for COX-2 gene significantly reduced the expression level of COX-2 protein and mRNA and led inhibition of proliferation in 7901-AS cells. The tumor graft of 7901-AS in nude mice 30 days after implantation had less volume and weight than that of SGC7901 and 7901-P [(486.67 +/- 15.28) mg vs (826.67 +/- 77.67) mg and (776.67 +/- 300.06) mg, P < 0.01]. CONCLUSIONS: Overexpression of COX-2 in human gastric cancer cell line SGC 7901 was related to the malignant phenotype of cancer cells. Inhibition of COX-2 expression by antisense technique could reverse malignant phenotypes of gastric cancer cells.