SiRNA-Survivin增强鼻咽癌细胞对放射敏感性的实验研究

SiRNA-survivin enhancing radiation effect on nasopharyngeal carcinoma cells

目的研究Survivin表达抑制对鼻咽癌放射敏感性的影响,探讨Survivin基因为靶的分子干预在鼻咽癌放疗中作用。方法采用脂质体将Survivin特异性siRNA转染鼻咽癌5-8F细胞系,半定量RT-PCR、流式细胞仪检测Survivin基因表达;Survivin特异性siRNA转染5-8F细胞,培养24h后,用6GY的放射线处理细胞,继续培养24h后,收集细胞。流式细胞仪、镜下计数检测细胞增殖、凋亡与细胞周期。结果Survivin特异性的siRNA能有效地阻断5-8F细胞系中Survivin基因表达。特异性SiRNA加放射组,细胞抑制率(33.7±1.5%)显著高于特异性SiRNA组([23.8±4.3)%,(P<0.05)]和随机序列的siRNA加放射组([15.5±1.7)%,(P<0.01)]。特异性SiRNA加放射组,细胞凋亡率(24.67±0.50)显著高于特异性SiRNA组([20.30±0.44),(P<0.05)]和随机序列的siRNA加放射组([6.58±0.38),(P<0.01)]。特异性siRNA加放射组,S/G1比率(2.76±0.186)显著高于特异性siRNA组([1.91±0.067),(P<0.01)]与随机序列的siRNA加放射组([0.585±0.066),(P<0.01)]。结论有效干预Survivin基因表达能提高鼻咽癌细胞的放射敏感性,增强鼻咽癌的放疗效果。

[Objectives] To investigate the radiosensitivity on nasopharyngeal cancer with survivin expression suppressed, and determine the function of survivin gene target in nasopharyngeal carcinoma with irradiation therapy. [Methods] Survivin specific siRNA （small interfere RNA） was transfected into nasopharyngeal carcinoma cell line 5- 8F by liposome, survivin expression was detected by semi--quantitive RT-PCR and flow cytometry. Survivin specific siRNA was transfeeted into 5- 8F cell line, after cultured 24 h, irradiated with 6 Gy radiation, cultured another 24 h, cells were harvested. Then, cell proliferation, apoptosis and cell cycle were respectively detected by flow cytometry and cell count. [ Results ] Expression of survivin was suppressed by survivin specific siRNA in 5-8F cell line. The inhibition rate of cell proliferation was significantly higher in specific siRNA ＋ irradiation group （33.7±1.5%） than that in specific siRNA group （23.8±4.3%, P 〈0.05） and random sequence of siRNA＋irradiation group （15.5±1.7%, P 〈0.01）. The apoptosis rate of specific siRNA ＋ irradiation group （24.67±0.50%） was significantly higher than in specific siR- NA group （20.30±0.44%, P 〈0.05） and random sequence of siRNA ＋ irradiation group （6.58±0.38, P 〈0.01）. The S/G1 ratio of siRNA ＋ irradiation group （2.76±0.186） was significantly higher than that in specific siRNA group （1.91±0.067, P 〈0.01） and random sequence of siRNA ＋ radiotherapy group （0.585±0.066, P 〈0.01）. [ Conclusions] Suppression of survivin expression enhances the effect of irradiation on nasopharyngeal carcinoma.