羟基喜树碱诱导SMMC-7721细胞线粒体跨膜电位耗散的蛋白质组分析

Proteomic analysis of mitochondrial proteins in hydroxycamptothecin-treated SMMC-7721 cells

目的比较蛋白质组,分析羟基喜树碱诱导肝癌细胞株SMMC-7721细胞凋亡前后的线粒体蛋白质表达谱。方法用羟基喜树碱诱导肝癌SMMC-7721细胞发生线粒体跨膜电位耗散,提取线粒体并用Western blot法对线粒体纯度进行鉴定；用二维凝胶电泳分离溶解度不同的3种蛋白质组分并对蛋白质进行银染色；利用PDQuest图像分析软件分析比较凝胶结果,获得差异蛋白质；采用基质辅助激光解析电离飞行时间质谱鉴定部分差异蛋白质,并用Western blot法对部分差异蛋白质进行进一步的鉴定。结果羟基喜树碱成功地诱导线粒体发生跨膜电位耗散,并获得纯度很高的线粒体；通过PDQuest图像分析软件发现,线粒体发生跨膜电位耗散前后比较约有39个蛋白质点表达有差异,对其中28个差异蛋白质斑点进行了肽质指纹图分析,鉴定出20种可能的蛋白质。结论获得了羟基喜树碱诱导线粒体凋亡前后差异蛋白的相关信息,为从蛋白质水平进一步研究羟基喜树碱诱导癌细胞发生凋亡的机制奠定了基础。

Objective To investigate the differentially expressed mitochondrial proteins in hydroxycamptothecin （HCPT）-treated SMMC-7721 cells by comparative proteomic analysis. Methods Apoptosis of SMMC-7721 cells were induced by using HCPT and their mitochondria were isolated with a mitochondria isolation kit for cultured cells. Three different solubility protein fractions were extracted with ReadyPrep Sequential Extraction Kit and were separated by two-dimensional gel electrophoresis （2-DE）. PDQuest software was used to differentiate mitochondrial proteins between control cells and HCPT-treated cells. Matrix assisted laser desorption/ionization time of flying mass spectrometry （MALDI-TOF-MS） was used to identify some of the different proteins. Results Highly purified mitochondria and high resolution 2- DE patterns of the proteins were obtained. Forty-four mitochondrial protein spots from the HCPT-treated cells showed different expressions compared to those of the control cells. Twenty of the different protein spots were analyzed by MALDI-TOF-MS. Conclusion Differently expressed mitochondrial proteins in HCPT-treated cells and control cells were obtained in this study. This will be of help to understand the mechanism by which HCPT induces cell apoptosis.