目的:观察survivin特异性小干扰 RNA (small interference RNA, siRNA)对P53野生型和P53 缺失型肺癌细胞株的生长抑制作用， 分析肺癌细胞中survivin 与 mP53的相关性 。 方法 ：以化学合成的survivin siRNA转染 P53野生型肺癌细胞株A549和P53缺失型肺癌细胞株H1299，用MTT 法检测转染前后肺癌细胞的增殖情况，流式细胞术分析细胞周期和凋亡的改变，半定量 RTPCR 检测转染对survivin mRNA表达的影响，Western blotting 检测survivin、 PARP、 P21、 P53等蛋白表达的变化。 结果：siRNA转染前A549 细胞中survivin表达量明显低于 H1299 细胞(P<0.05)。 Survivin siRNA 转染组两种细胞 survivin 蛋白及 RNA 表达水平均显著低于对照组和无关干扰组(P<0.01)。Survivin siRNA 对 A549 和 H1299细胞生长抑制作用均呈浓度依赖性(P<0.05)，但对H1299细胞的抑制起效晚于A549，且抑制程度低于A549细胞。转染后 A549和 H1299 细胞均有 G1 期比例增加和 S 期比例相应地减少，H1299 细胞的变化更为显著。 A549 细胞有一定比例出现凋亡，PARP 发生了裂解，P53、 P21蛋白表达增加，而H1299 细胞中上述指标的变化却不明显。 结论：P53野生型 A549细胞内源性survivin表达明显低于P53缺失型H1299细胞；抑制survivin能上调P53蛋白表达，其对A549细胞的生长、凋亡和P21等蛋白表达的影响明显强于H1299细胞；提示survivin与P53之间可能存在着相互抑制作用。

Objective:To observe the inhibitory effects of survivinspecific siRNA on human lung cancer cell lines with different P53 statuses, and to analyse the relationship between P53and survivin in vitro. Methods: A549 (wildtype P53) and H1299 (P53absent) cells were transfected with chemosynthetic survivin siRNA. The effect of siRNA on cell proliferation was analysed by MTT assay. The changes of cell cycle and apoptosis were examined by flow cytometry. The expression of survivin mRNA was detected by RTPCR. The protein expression of survivin, P53, P21 and PARP was examined by Western blotting. Results:Endogenous survivin level in A549 cells was lower than that in H1299 cells. The mRNA and protein expression of survivin was significantly lower in siRNA group than in blank control group and nonsilencing siRNA group (P<0.01). Survivinspecific siRNA significantly inhibited the growth and proliferation of both A549 and H1299 cells in a concentration dependent manner (P<0.05), but the inhibitory effect was earlier and more efficient in A549 cells than in H1299 cells. Survivinspecific siRNA produced an increase in the G1 fraction and a decrease in S fraction in the two cell lines, with the changes in the latter more evident. Apoptosis was found in A549 cells; PARP was cleaved and P21 and P53 protein was increased in A549 cells. The above changes were not obvious in H1299 cells. Conclusion: Endogenous survivin levels in A549 (wildtype P53) cells is lower than that in H1299 (without P53) cells. Inhibition of survivin by transfecting survivin siRNA can significantly upregulate P53 protein expression in A549 cells. The effects of survivin siRNA on the cell growth, apoptosis and expression of some proteins are more prominent in A549 than in H1299 cells, suggesting that survivin and P53 might inhibit each other.

全军医药科研基金课题(No.01MA101).