外源性p27KIP1基因抑制SGC7901细胞的增殖

研究p27^KIP1基因对胃癌细胞的细胞周期及细胞增殖的影响。采用脂质体转染法将p27^KIP1全长cDNA转入胃癌细胞系SGC7901中，通过免疫屯迹分析以及RNA斑点杂交方法检测p27^KIP1基因在蛋白质和mRNA水平的表达，细胞活力实验及软琼脂集落形成实验显示转染p27^KIP1基因对细胞增殖的作用；流式细胞仪观察目的的基因对该细胞的细胞周期的影响。结果显示，转染p27^KIP1的SGC7901细胞在mRNA和蛋白质水平均有高水平p27^KIP1的表达；细胞活力检测显示在外加Zn离子48h后细胞生长被抑制42％；转染p27^KIP1的SGC7901细胞的集落形成率较对照组明显减少（P＜0．01）；p27^KIP1的过表达能够显著地增加G1期的细胞数，由33．68％增加到69．29％（P＜0．01）。研究表明，p27^KIP1基因可抑制SGC7901细胞由G1期向S期过渡，从而抑制细胞增殖。

OVEREXPRESSION OF p27KIP1 INHIBITS GROWTH OF SGC7901 CELLS

To elucidate the effect of p27 KIP1 on cell cycle and proliferation of gastric carcinoma cells, we transfected the full e length cDNA of p27 KIP1 into human SGC7910 gastric cancer cells by the method of lipofectin transfection. Expression of p27 KIP1 at protein or mRNA level was analyzed by Western blotting, and RNA dot blotting, respectively. Effect of p27 KIP1 on cell growth was observed by trpan blue exclusion assay and anchorage independent growth in soft agar. Flow cytometry was applied to assess the effect of p27 KIP1 on cell cycle. The results showed that the expression of p27 KIP1 at protein or mRNA level increased evidently in SGC7901 cells transfected with p27 KIP1 . The cell growth was reduced by 42% 48h post induction with zinc as determined by cell viability assay. The rate of anchorage independent growth in soft agar decreased significantly. p27 KIP1 over expression caused cell arrest at G 1 by 36%(from 33 68% to 69 29%, P <0 01) increase. This phenomenon demonstrated that p27 KIP1 can inhibit transition from G 1 to S phase in SCG7901 cells and inhibit cell growth. p27 KIP1 can be used as an agent for gene therapy.