腺病毒介导的p27kip1基因对胃癌细胞周期和DNA合成的影响

背景：近年来胃癌基因治疗的研究取得了一定的进展，但总体疗效尚不尽人意，目前正积极寻求组织特异性基因作为胃癌基因治疗的突破点。目的：以腺病毒为载体，研究p27kipl基因对胃癌细胞周期和DNA合成的影响。方法：将成功构建的携带人p27kipl基因的重组腺病毒载体Ad-p27kipl和LacZ重组腺病毒Ad-LacZ转染胃癌细胞系SGC-7901，并观察细胞形态的变化，流式细胞仪检测细胞周期和凋亡，^3H-胸腺嘧啶核苷(TdR)掺入实验测定细胞DNA合成。结果：Ad-p27kip1转染SGC-7901细胞后，细胞变圆、呈葡萄串样聚集以致脱落，G0／G1期细胞比例增加，8期、G2／M期细胞比例降低，并有凋亡发生，^3H-TdR掺入量亦显著降低。结论：腺病毒介导的p27kipl基因能使SGC-7901细胞产生G0／G1期阻滞，并能诱导细胞凋亡，抑制DNA合成，表明该基因疗法能有效抑制体外胃癌细胞的生长。

Effect of p27kip1 Gene Mediated by Adenovirus on the Cell Cycle and DNA Synthesis in Gastric Cancer Cells

In recent years, the investigators have made some progress in the gene therapy of gastric cancer; however, the overall efficacy is not satisfactory. Tissue specific genes are sought to be the breakthrough point for gene therapy of gastric cancer at present. Aims: To investigate the effect of p27kipl gene on the cell cycle and DNA synthesis in gastric cancer cells by using adenovirus as the vector. Methods: The successfully constructed recombinant adenoviral vector Ad-p27kipl carrying human p27kipl gene and LacZ recombinant adenovirus Ad-LacZ were transfected to gastric cancer cell line SGC-7901. The morphologic changes of SGC-7901 cells were observed, the cell cycle and apoptosis were detected by flow cytometry, and DNA synthesis evaluated by ~3H-thymidine (TdR) incorporation, Results: After transfected with Ad-p27kipl, the SGC-7901 cells became round, botryoidal aggregate like, and exfoliating. The ratio of G0/G1 phase cells increased, while the ratio of S phase and G2/M phase cells decreased makedly. Apoptosis was found and ~3H-TdR incorporation decreased significantly. Conclusions: p27kipl gene mediated by adenovirus can cause blockage of G0/G1 phase cells, induce apoptosis and inhibit DNA synthesis in SGC-7901 cells, which indicate that this gene therapy can effectively inhibit the growth of gastric cancer cells in vitro.