Fas抗体诱导的膀胱癌细胞凋亡

背景与目的：Fas是死亡因子,可以诱导细胞的凋亡性死亡,但许多表达Fas的恶性肿瘤细胞却不能进行凋亡性死亡,可能与其表达水平低下有关,为此我们研究了细胞Fas表达水平与抗Fas治疗生物学效应之间的相互关系。方法：分别将低表达Fas的膀胱癌细胞系EJ细胞进行脂质体介导的方法转染Fas基因和肿瘤坏死因子α（TNFα)处理,并用流式细胞直接免疫荧光术检测Fas的表达;单细胞电泳和流式细胞技术检测鼠抗人Fas单克隆抗体DX2 IgG1κ诱导转染Fas基因的、经TNFα处理的和未转染未处理的EJ细胞的细胞DNA损伤和凋亡。结果：流式细胞直接免疫荧光术检测EJ细胞Fas表达阳性率19．18％,经TNFα处理后的EJ细胞Fas表达阳性率28．03％,转染Fas基因后的EJ细胞Fas分子表达阳性率68．69％。鼠抗人Fas单克隆抗体DX2 IgG1κ诱导的EJ细胞组细胞电泳后所产生的拖尾现象轻微;DX2 IgG1κ对TNFα处理组的拖尾现象明显,而对转Fas基因组可引起最强的细胞拖尾现象,经统计学分析后表明,3组细胞的尾长与总长的比值之间差异均有显著统计学意义,P＜0．01;流式细胞技术检测EJ细胞和转Fas基因组EJ细胞中的凋亡细胞分别为7．4％和66．3％。结论：EJ细胞系对Fas抗体触发细胞凋亡的敏感性依赖于细胞表面Fas的表达水平。

Detection of cell apoptosis induced with anti-Fas antibody in bladder carcinoma cell line by single cell gel electrophoresis

BACKGROUND & OBJECTIVE: Fas, a death factor, can induce apoptotic death of cells. Many malignant tumor cells expressed Fas can not develop apoptotic death, this may be because of low Fas expression. Therefore we investigate the relationship between expression level of Fas and anti-Fas biological responsiveness. METHODS: With direct immunofluorescence flow cytometry, the expression of Fas was detected in bladder carcinoma cell line EJ, TNF alpha treated EJ, and Fas gene transfected EJ. The three kinds of EJ cells died by apoptosis were induced with anti-Fas antibody DX2 IgG1K and determined by SCGE and flow cytometry (FCM). RESULTS: Expression of Fas in bladder carcinoma cell line EJ, TNF alpha treated EJ, and Fas gene transfected EJ was 19.18%, 28.03%, and 68.69%, respectively. Cellular apoptosis induced with anti-Fas antibody DX2 IgG1K in bladder carcinoma cell line EJ was least, in TNF alpha treated EJ moderate, and in Fas gene transfected EJ the most. CONCLUSIONS: Fas gene transfection is an effective method to increase Fas expression; the sensitivity of EJ cell line to Fas-mediated apoptosis is mainly dependent upon the expression of Fas.