Ku80沉默增强鼻咽癌细胞放射敏感性并诱导凋亡

Silencing expression of Ku80 enhances the radiosensitivity and induces apoptosis in nasopharyngeal carcinoma cell

目的:研究Ku80沉默对鼻咽癌细胞系放射敏感性和凋亡的影响。方法:q RT-PCR测定鼻咽癌细胞系和正常鼻咽部细胞系中Ku80 m RNA的相对表达水平;将鼻咽癌细胞系CNE2分成对照组、阴性对照Sh RNA组及Ku80 Sh RNA组,分别不感染慢病毒、感染阴性Sh RNA慢病毒、感染Ku80 sh RNA慢病毒,测定3组的感染效率,将上述3组细胞分别照射0,2,4,6,8及10 Gy,测定三组细胞存活率;流式细胞术测定细胞凋亡率。结果:Ku80 m RNA在鼻咽癌细胞系CNE2,CNE1,HONE-1及C666中相对表达量分别为9.0±0.9,8.0±0.3,5.0±0.4及4.0±0.2,Ku80 m RNA在正常鼻咽上皮细胞系NP69中的相对表达量为1.0,Ku80 m RNA在鼻咽癌细胞系中的相对表达量显著高于正常鼻咽上皮细胞系NP69,差异有统计学意义(P<0.05)。慢病毒感染后,Ku80 sh RNA组Ku80 m RNA的相对表达量为0.1±0.03,显著低于阴性对照sh RNA组的0.93±0.04,差异有统计学意义(P<0.001);Ku80s h R N A组Ku 8 0蛋白相对表达量为0.1 5±0.0 5,显著低于阴性对照s h R N A组的1.0,差异有统计学意义(P<0.001)。Ku80 sh RNA组的细胞存活率显著低于对照组和阴性对照sh RNA组;照射后48 h,Ku80 Sh RNA组细胞凋亡率为20.0%±0.9%,对照组及阴性对照Sh RNA组凋亡率分别为4.3%±0.8%,5.0%±0.8%,Ku80 Sh RNA组凋亡率显著高于对照组和阴性对照Sh RNA组。结论:Ku80沉默表达可增强鼻咽癌细胞放射敏感性,并诱导细胞凋亡,沉默Ku80表达有望成为鼻咽癌放射增敏的靶点。

Objective： To investigate the effect of silencing Ku80 expression on radiosensitivity and apoptosis in nasopharyngeal carcinoma cell. Methods： q RT-PCR was used to measure the expression level of Ku80 m RNA in nasopharyngeal carcinoma cell and normal nasopharyngeal cell. The CNE2 cells were divided into three groups： a control group transfect with no lentiviral, a negative control Sh RNA group transfect with negative control lentiviral, and a Ku80 Sh RNA group transfect with Ku80 sh RNA lentiviral. The transfect efficiency was compared between the 3 groups. These 3 groups were irradiated with 0, 2, 4, 6, 8 and 10 Gy. The cell survival rate was measured and compared in these 3 groups. And apoptosis rate was also tested. Results： The expression levels of Ku80 m RNA in CNE2, CNE1, HONE-1 and C666 cell line were 9.0±0.9, 8.0±0.3, 5.0±0.4, 4.0±0.2, which was significantly higher than 1.0 in the normal nasopharyngeal epithelium cell line, NP69, the difference was statistically significant（P〈0.05）. The expression level of Ku80 m RNA in Ku80 sh RNA group was 0.1±0.03, which was significantly lower than 0.93±0.04 in the negative control Sh RNA group, the difference was statistically significant（P〈0.001）. The expression level of Ku80 protein was 0.15±0.05 in the Ku80 sh RNA group after lentiviral transfection, which was significantly lower than 1.0 in the negative control Sh RNA group（P〈0.001）. The cell survival rate in the Ku80 sh RNA group was significantly lower than that in the control and the negative sh RNA control group. The apoptosis rate of the Ku80 Sh RNA group was 20.0%±0.9%, which was significantly higher than 4.3%±0.8% in the control group and 5.0%±0.8% in the negative sh RNA control group. Conclusion： Silencing of Ku80 via sh RNA interference can enhance the radiosensitivity and induce apoptosis in nasopharyngeal carcinoma cell. Silencing Ku80 expression may become a target of enhancement of the radiosensitivity in nasopharyngeal carcinoma.