人类解旋酶样转录因子过表达促进辐射诱导的A549细胞凋亡  

Increased apoptosis of A549 cells by overexpression of helicase-like transcription factor induced by radiation exposure

作　　者：孙艳[1] 韩云[1] 朱应葆[1] 

机构地区：[1]北京大学第三医院中心实验室,100083

出　　处：《中华放射医学与防护杂志》2010年第5期507-509,共3页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金（30470976）

摘　　要：目的 探讨人类解旋酶样转录因子（HLTF）对辐射诱导细胞凋亡的影响及其机制.方法 将空质粒和带FLAG标签的HLTF表达质粒分别转染人肺癌细胞A549,60Coγ射线照射观察细胞凋亡变化.用Western blot检测HLTF在细胞核和胞质内水平的变化及线粒体细胞色素C的释放.结果 HLTF转染可促进γ射线诱导的细胞凋亡,凋亡率为（32.2±2.1）%,高于空载体转染组（11.4±2.3）%和Mock转染组（11.1±1.8）%（F=101.85,P＜0.01）.辐射后HLTF在胞质内的表达水平显著提高.HLTF转染组胞质内细胞色素C的水平亦显著提高.结论 HLTF可促进辐射损伤诱导的细胞凋亡,其部分机制可能是通过提高核质转位以及影响线粒体细胞色素C的释放来实现的.Objective To study the effects of overexpression of helicase-like transcription factor （HLTF） on radiation-induced apoptosis of human lung carcinoma cells.Methods Human lung carcinoma cellline A549 were cultured,transfected with FLAG-tagged HLTF expression plasmid pcDNA3.1/HLTF-FLAG （HLTF gene transfection group） ,empty plasmid vector pcDNA3.1 （empty vector group） ,and mock transfection group,respectively,and then exposed to 60Co γ-ray irradiation.Cell apoptosis was observed by flow cytometry 48 h post-irradiation.Western blotting was used to detect the levels of HLTF in the nucleus and cytoplasm and the release of cytochrome C from mitochondria into cytoplasm.Results The apoptosis rate of the HLTF gene group was （32.2 ± 2.1） %,significantly higher than those of the empty vector group [（11.4±2.3）%] and mock transfection group [（11.1 ±1.8）%] （F=101.85,P＜0.05）.The level of cytochrome C in the cytoplasm of the HLTF gene group was significantly higher than that of the empty plasmid group.Conclusions HLTF protein sensitizes human lung carcinoma cells to radiation-induced apoptosis,partly by promoting the nuclear-cytoplasma transition of HLTF protein and the increased release of cytochrome C.

关 键 词：细胞凋亡 人类解旋酶样转录因子(HLTF) 细胞色素C 

分 类 号：R346[医药卫生—基础医学]