人脑髓鞘碱性蛋白对H_2O_2诱导人肺癌细胞YTLMC-90凋亡的抑制作用  

Inhibitory Effect of Human Brain Myelin Basic Protein on H_2O_2-induced Apoptosis of Human Lung Cancer Cell Line YTLMC-90

作　　者：陈建业[1] 王晓明[2] 刘戟[1] 陈璟歆[3] 王若菡[1] 彭文珍[1] 程汉华[1] 陈俊杰[1] 

机构地区：[1]四川大学华西基础医学与法医学院生物化学与分子生物学研究所,四川成都610041 [2]川北医学院神经电生理研究所,四川南充637007 [3]川北医学院生物化学教研室,四川南充637007

出　　处：《癌症》2006年第2期170-174,共5页Chinese Journal of Cancer

摘　　要：背景与目的:人脑髓鞘碱性蛋白(myelinbasicprotein,MBP)广泛分布于神经系统及多种非神经组织之中,而且在肺癌、乳腺癌、神经胶质瘤等多种肿瘤细胞中均检查到MBP的表达。但MBP与癌细胞侵犯神经组织的活性是否相关、与肺癌细胞的生物学行为是否相关尚未见报道。本研究主要探讨MBP对过氧化氢(H2O2)诱导人肺癌细胞YTLMC-90凋亡的影响。方法:实验分为MBPcDNA微基因pSVCEPMBPCAT转染组(试验组)、空质粒pSVCEPCAT转染组和未转染组(对照组)。将含人Ⅰ型胶原a1链(COLⅠA1)基因启动子和增强子元件、并在其3′端接MBPcDNA的微基因,转染YTLMC-90细胞,并驱动MBP异位表达;采用MTT法检测细胞增殖,吖啶橙荧光染色显微镜和电镜观察细胞形态及其超微结构的改变;琼脂糖凝胶电泳检测染色质DNA断裂。结果:200μmol/LH2O2作用24h后,转染组、未转染组和空载体pSVCEPCAT转染组YTLMC-90细胞的生长抑制率分别为36.67%、84.00%和78.67%(P<0.001);对照组YTLMC-90细胞普遍可见凋亡细胞特有的形态学及生物化学改变,如胞核固缩、染色质断裂,DNA电泳呈梯状条带;而MBPcDNA微基因转染的YTLMC-90细胞未发现上述凋亡特征。结论:MBP促进YTLMC-90细胞增殖和拮抗H2O2诱导的凋亡,明显减少H2O2对YTLMC-90的细胞毒作用。BACKGROUND ＆ OBJECTIVE. Human brain myelin basic protein （MBP） distributes in nervous system and other tissues extensively, and can be detected in many kinds of tumor cells, such as lung cancer, breast cancer, and neuroglioma. However, it has not been reported whether MBP is relevant to the activity of neural invasion of tumors and whether MBP plays a role in biological behaviors of human lung cancer cells. This study was to investigate the inhibitory effect of MBP on hydrogen peroxide （H2O2）- induced apoptosis of human lung cancer cell line YTLMC-90. METHODS. YTLMC-90 cells were transfected with plasmid pSVCEPMBPCAT containing MBP cDNA minigene （test group）, or empty vector pSVCEPCAT, or received no transfection （control group）, and exposed to H2O2. The expression of MBP in YTLMC-90 cells was detected by Western blot. Cell proliferation was measured by MTT assay. The morphologic and ultrastructural changes of apoptotic cells were observed by microscopy with fluorescent staining of acridine orange （AO） and electron microscopy. The DNA fragmentation was examined by agarose gel electrophoresis. RESULTS. After exposed to 200μmol/L H2O2 for 24 h, the inhibitory rate of cell growth was significantly lower in test group than in empty vector group and control group （36.67% vs. 78.67% and 84.00%, P〈0.001）. The morphologic and biochemical changes of apoptotic cells, such as shrinkage of cytoplasm and nucleus, fragmentation of chromatin, and ladder pattern of DNA, were commonly observed in cells in control group, but these apoptotic features were not discovered in test group. CONCLUSION. MBP markedly inhibits H2O2 cytotoxicity to YTLMC-90 cells through promoting cell proliferation and antagonizing H2O2-induced apoptosis.

关 键 词：髓鞘碱性蛋白 微基因 过氧化氢 肺肿瘤 YTLMC-90细胞系 凋亡 

分 类 号：R734.2[医药卫生—肿瘤]