EGF及IGF－Ⅰ对UMR106细胞增殖及β微管蛋白表达的影响

应用３Ｈ－ＴｄＲ参入，流式细胞技术和Ｎｏｒｔｈｅｒｎｂｌｏｔ等方法，观察了ＥＧＦ和ＩＧＦ－Ⅰ对ＵＭＲ１０６细胞增殖及β微管蛋白表达的影响。结果显示，两种生长因子分别处理ＵＭＲ１０６细胞１２ｈ，在促进细胞ＤＮＡ合成的同时，β微管蛋白ｍＲＮＡ的表达量明显提高。运用间接免疫荧光技术及Ｗｅｓｔｅｒｎｂｌｏｔｔｉｎｇ方法，研究发现两种生长因子可使微管聚合及微管蛋白的表达有所增加。提示β微管蛋白的合成及聚合与细胞增殖间可能存在着一定的相互联系．

Proliferative Effect of EGF and IGF-Ⅰon the Expression of β-Tubulin in UMR106 Cells

Recent studies indicates that the free tubulin and microtubules are involved in regulating initiation of cell proliferation. In this experiment ,rat osteoblastsarcoma UMR106 cell line was used to study the effects of epidermal growth factor(EGF) and insulin-like growth factor I(IGF-Ⅰ)on the expression of tubulin and its relationship to cell proliferation. These two kinds of growth factors are the potent effector on cell proliferation in most cells. UMR106 cells were treated with EGF(10 ng/ml) or IGF-Ⅰ(10-8 mol/L) for 12 hours. It was revealed that 3H-TdR incorporation increased by 64. 91% and 93. 57% respectively,and the percentage of cells in S stage increased remarkably. In the case of EGF, it increased from 51. 1% to 72.0%. In the meantime,results of Northern bolt analysis of equal amount of total RNA extracted from cells trcated with EGF or IGF-Ⅰ,also revealed that the expression of the β-tubulin mRNA increased by 42. 2% and 11. 61% respectively, Using indirect immunofluorenscent staining to observe the microtrbule inside cells,the increase of microtubule polymerization was predominent in EGF or IGF-Ⅰtreated cells. It was concluded that EGF and IGF-Ⅰcan increaseβ-tubulin gene expression, tubulin biosynthesis and polymerization effectively in UMR106 cells. This process may be involved in the initiation of cellular DNA synthesis and accelerate mitogenesis.