中文摘要：

目的：探讨Slit－Robo信号对黏液表皮样癌细胞凋亡的影响及其作用机制。方法：免疫组织化学方法检测Mc3细胞Slit2及Robol蛋白表达，R5单克隆抗体作用Mc3细胞，采用FITC－AnnexinV／PI法检测细胞凋亡率，流式细胞仪检测细胞周期，DNA梯状电泳及Hoechst/PI双染法检测细胞凋亡发生。流式细胞仪细胞内抗原检测法检测Caspase－3蛋白含量。结果：Mc3细胞表达Slit2及Robol蛋白，R5抗体作用下细胞凋亡率增高，达到33．6％，形态学观察凋亡细胞明显增多并出现坏死细胞，电泳结果出现梯状条带，S期细胞明显增多，Caspase－3表达水平上调，平均荧光强度达到64％。结论：黏液表皮样癌中Slit－Robo信号可能以抑制细胞凋亡的形式参与肿瘤的形成过程，而这可能是通过Caspase－3蛋白的表达调控实现的。

英文摘要：

Objective： To study the effects of the Slit-Robo signal on the apoptosis of human mucoepidermoid carcinoma Mc3 cells. Methods： Slit-2 and Robo-1 protein expression in Me3 cells was detected with immunohistochemical method. After the treatment of the monoclonal antibodies （ mAb ） R5 against Robol receptor extracellular domain, the FITC-AnnexinV/PI method was used to determine the apoptotic rate of the Mc3 cells. Flow cytometry was conducted to detect the cell cycle. Apoptosis of Me3 cells was detected by DNA gradient gel electrophoresis and Hoechst/PI double staining assays. Flow cytometric analysis and intracellular antigen assay were conducted to measure the caspase-3 protein level. Results： Positive expression of Slit-2 and Robo-1 could be detected in Me3 cells. The apoptotic rates, reaching 33.6%, were caused by the effects of the R5 antibody treatment. Morphological changes indicated the increase in apoptosis and the occurrence of necrosis. The typical DNA ladder was found in the electrophoresis pattern, and the cell cycle distribution of Mc3 cells was significantly increased at the S phase. The caspase-3 expression was upregulated, and the average fluorescence intensity reached 64%. Conclusions： Slit-Robo signal may play a crucial role in the development of tumors. This signal could inhibit tumor cell apoptosis during oncogenesis of the mucoepidermoid carcinoma by regulating the caspase-3 protein expression, which may be one of the important transductions in the Mc3 cell apoptosis.