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极低频磁场(ELF MF)被国际癌症研究中心列为可疑致癌物,但其诱发肿瘤的具体机制并不清楚.为此,采用蛋白质组技术研究人乳腺癌细胞MCF7受ELF MF辐照后蛋白质表达谱的变化,以探索确定该细胞的极低频磁场反应蛋白质.在将MCF7细胞暴露于50Hz,0.4mT正弦极低频磁场中24 h后,直接抽提蛋白,进行双向凝胶电泳.凝胶经银染后,使用PDQuest软件分析假辐照组与磁场辐照组间差异表达蛋白质斑点.结果显示,与假辐照组相比,磁场辐照组中有6 个蛋白质斑点的表达量发生显著改变(至少5倍的增加和减少),同时,在磁场辐照组中有19个蛋白点消失和19个新蛋白点出现.通过搜索SWISS—PROT蛋白数据库,对差异蛋白的类别和功能进行了初步推测.在此基础上,进一步选择3个差异表达蛋白斑点,经胶内酶解后,进行串联质谱分析,分别鉴定为RNA结合蛋白调节亚基、蛋白酶体β亚基7型前体和翻译调控肿瘤蛋白.结果表明,50 Hz,0.4 mT极低频磁场辐照24 h改变了MCF7细胞内多种蛋白的表达水平,影响环节涉及基因转录、蛋白翻译、蛋白代谢、功能蛋白相互作用等多个层面,说明极低频磁场可能作为一种环境应激因素改变细胞的正常生理功能.
ELF MF has been classified as a suspected carcinogen by the International Agency for Research on Cancer but its exact mechanism of tumor induction is not clear.Therefore, proteomic technology was used to study the protein expression of human breast cancer cell line MCF7 after ELF MF irradiation Spectrum changes to explore to determine the cells of the very low frequency magnetic field reaction protein MCF7 cells exposed to 50Hz, 0.4mT sinusoidal low-frequency magnetic field for 24 h, direct extraction of proteins, two-dimensional gel electrophoresis gel by silver After staining, PDQuest software was used to analyze the differentially expressed protein spots between the sham irradiation group and the magnetic field irradiation group.The results showed that compared with the sham irradiation group, there were 6 protein spots in the magnetic field irradiation group significantly changed At least 5 fold increase and decrease), while at the same time, there were 19 protein spots disappeared and 19 new protein spots appeared in the magnetic irradiation group.A preliminary speculation on the types and functions of the differentiated proteins was carried out by searching the SWISS-PROT protein database On the basis of this, three differentially expressed protein spots were further selected, and after in-gel digestion, tandem mass spectrometry was performed and identified as RNA binding protein regulatory subunit, proteasome β subunit type 7 precursor and translational regulation Tumor protein.The results showed that the radiation of 50 Hz and 0.4 mT ultra-low frequency magnetic field for 24 h changed the expression of many proteins in MCF7 cells, which affected many aspects such as gene transcription, protein translation, protein metabolism and functional protein interaction , Indicating very low frequency magnetic field may act as an environmental stress factor to change the normal physiological function of cells.