小干扰RNA沉默Bcl-2表达增强食管癌细胞放射敏感性研究

目的 探讨Bcl-2基因的特异性小干扰RNA (siRNA)对食管癌细胞(EC9706细胞)Bcl-2蛋白表达和凋亡的影响及放射增敏作用。方法 化学合成Bcl-2基因的siRNA,通过脂质体转染法转入EC9706细胞。流式细胞仪检测转染前后Bcl-2蛋白表达及细胞凋亡,成克隆分析siRNA联合X线照射对EC9706细胞的放射敏感性影响。结果 Bcl-2 siRNA1、Bcl-2 siRNA2、Bcl-2 siRNA3转染后Bcl-2蛋白在EC9706细胞中的阳性表达率分别为25.13％、38.87％、30.55％,较对照组的84.28％明显下降(t =4.01、3.04、3.64,P均＜0.05)。Bcl-2 siRNA1转染组凋亡率为33.86％,明显高于空白对照组的5.51％(t=6.55,P＜0.01)和阴性siRNA1转染组的5.59％(t=6.54,P＜0.01);Bcl-2 siRNA1联合X线照射的细胞凋亡率为56.76％,明显高于单纯照射组的24.51％(t=3.59,P＜0.05)。成克隆分析的Bcl-2 siRNA1转染加照射组D0、Dq、SF2值均低于单纯照射组,放射增敏比为1.33(D0值之比)。结论 Bcl-2基因的特异性siRNA可明显增强EC9706细胞的放射敏感性,具有良好临床应用前景。

Small interfering RNA in silencing Bcl-2 expression and enhancing radiosensitivity of esophageal cancer cells

Objective To explore the effects of small interfering RNA (siRNA) specific to Bcl-2gene on radiosensitivity of esophageal cancer cells. Methods Bcl-2 gene siRNA ( Bcl-2 siRNA ) was induced into esophageal cancer EC9706 cells by lipofectamine. Bcl-2 protein expression and apoptosis of EC9706 cells were detected by flowcytometer. Clone forming assay was used to determine the inhibitory effects of X-ray radiation combined with Bcl-2 siRNA interference. Results When Bcl-2 siRNA had been induced into EC9706 cells, Bcl-2 protein expression in EC9706 cells was inhibited, and cell apoptosis was increased. Bcl-2 protein expression rates of EC9706 cells induced with Bcl-2 siRNA1, A2, A3 (25.13％ ±2. 04％ ,38.87％ ± 3.34％ , 30.55％ ± 2. 73％ ) were lower than the control group ( 84.28％ ± 1. 47％ )(t =4. 01,3.04,3.64, P ＜ 0. 05 ). After interference, the apoptosis rate of EC9706 cells ( 33.86％ ±1.04％ ) was higher than the control group and siRNA negative group (5.51％ ±0. 14％ and 5.59％ ±0. 46％ ) (t =6. 55,6. 54,P ＜0. 01 ). Bcl-2 gene siRNA interference enhanced X-ray inducing apoptosis of EC9706 cells (56.76％ ± 1.24％ ), which was higher than the radiation alone group ( 24.51％ ± 0. 48％ )(t =3.59,P ＜ 0. 05 ). The D0, Dq, and SF2 of combined treatment group were much lower than those of irradiation alone group . The sensitization enhancing ratio was 1.32 ( ratio of D0 values ) . Conclusions Bcl-2 gene siRNA could enhance the radiosensitivity of esophageal cancer EC9706 cells and may has a good future in clinical practice.