干扰TCAB1基因表达对鼻咽癌CNE-2细胞放射敏感性的影响

Effect of TCAB1 Inhibition on Radiosensitivity of Nasopharyngeal Carcinoma CNE-2 Cell Line

目的:探讨siRNA抑制TCAB1表达对鼻咽癌CNE-2细胞放射敏感性的影响及分子机制。方法:构建靶向抑制TCAB1的siRNA干扰质粒及阴性对照质粒,转染至CNE-2细胞,RT-PCR和Western-blot检测TCAB1表达;克隆形成实验检测细胞放射敏感性参数D0、SF2等;QPCR检测转染前后CNE-2细胞端粒的相对长度变化。结果:成功构建CNE-2/phTCAB1-siRNA干扰质粒,转染后RT-PCR和Western-blot分析表明TCAB1mRNA和蛋白表达均受到明显抑制,干扰组细胞D0和SF2值分别为2.490和0.460,明显低于空白对照组(D0和SF2值分别为3.186和0.607),P<0.01;QPCR检测端粒相对长度发现干扰组T/S值(0.19±0.01)均小于正常细胞(0.52±0.06)和转染阴性质粒细胞(0.42±0.01),P<0.05,而正常细胞组和转染阴性质粒细胞T/S值比较差异没有统计学意义(P>0.05)。结论:抑制TCAB1表达可以通过影响端粒长度增加鼻咽癌CNE-2细胞的放射敏感性,TCAB1有望成为一种新的肿瘤放射增敏靶点。

To observe the effect on the radiosensitivity of nasopharyngeal carcinoma CNE-2 cells after TCAB1 inhibition, and to analyze its molecular mechanism. Methods： phTCABI-siR- NA and pNeg-siRNA were constructed and were transfected into CNE-2 cells by lipofectamine, RT-PCR and Western-blot were used to analyze the expression of TCAB1, the radiosensitivity of CNE-2 cells was observed by using colony formation assay, and the relative length of telomerewas measured by QPCR. Results： The plasmid of phTCABI-siRNA was constructed successfully and its biological function was studied. The data of RT-PCR and Western-blot revealed that mR- NA and protein levels of TCAB1 were both inhibited obviously in the CNE-2 cells after being transfected with the plamid of phTCABI-siRNA. After the cells being irradiated with X-ray, the radiosensitivity indicators were detected, the Do and SF2 were 2. 490 and 0. 460 respectively in the phTCABI-siRNA group, which were much lower than those in the control group （the Do and SF2 were 3. 186 and 0. 607 respectively）, and statistical analysis showed that the difference between the two groups was significant（P〈0.01）. The relative telomere length was detected by QPCR, the T/S in the phTCABI-siRNA group was 0.19±0. 01, which were much lower than that re- spectively in the untreated group （0.52~0.06） and the control group （0.42±0.01）. Conclusion. Using RNA interference technique, decreasing the expression of TCAB1 can enhance the radio- sensitivity of CNE-2 cell line by influencing the telomere length. TCAB1 is expected to be a new target to regulate the radiosensitization of tumor cells.