NIH3T3细胞中PTPα基因高表达激活Src的早期细胞表型变化  

Changes of Phenotypes Associated with Activated Src by Overexpressed PTPα in NIH3T3 Cells

作　　者：杨劲松[1] 郑新民[2] 陈诗书[1] 

机构地区：[1]上海第二医科大学生化教研室,分子生物学实验室,人类基因治疗研究中心,上海200025 [2]美国康奈尔大学,纽约14850

出　　处：《生物化学与生物物理学报》2002年第2期193-198,共6页

摘　　要：利用蛋白质酪氨酸磷酸酶α(PTPα)基因转染NIH3T3细胞 ,研究PTPα诱导前后细胞生物学行为的变化 ,为肿瘤形成早期机制的研究提供细胞模型。用携带PTPα基因的四环素调控体系转染NIH3T3细胞并诱导 2 4h后 ,用RT PCR和蛋白质印迹法证实PTPα在诱导细胞中的表达高于未诱导细胞 ,用RT PCR及蛋白质印迹法发现内源性Src的表达水平在诱导与未诱导细胞中没有变化 ,而Src激酶的活性在诱导细胞中增高 ,并且在诱导细胞中Src的酪氨酸磷酸化水平降低。再用透射式电子显微镜和流式细胞技术观察到诱导细胞的表型已发生变化 ,实验结果表明PTPα诱导 2 4h使细胞的表型开始发生转化 ,这种变化很可能与PTPα表达水平升高使SrcC末端的pTyr52NIH3T3 cells transfected with inducible expression vectors harboring the protein tyrosine phosphatase α (PTPα) gene were used as a model to study the mechanism of tumor formation, by which the changes of phenotypes in inducible cells were studied.When NIH3T3 cells transfected with PTPα were induced for 24 hours, the expression levels of PTPα in inducible cells was higher than those in uninducible cells as judged by RT-PCR and Western blotting; the expression level of Src in inducible cells was the same as those in uninducible cells, but activity of Src kinase in inducible cells was higher than those in uninducible cells.The level of phosphated tyrosine in Src was reduced in inducible cells. The malignant changes of phenotypes in the inducible cells were verified by flow cytometry and electron microscope.The results show that 24 h induction of PTPα could initiate the transformation of NIH3T3 cells transfected with PTPα inducible expression vectors, and the transformation may be associated with activated Src where pTyr 527 in the C tail was dephosphorylated by increased expression level of PTPα in the cells.

关 键 词：PTPα SRC 细胞转化 基因表达 高表达激活 肿瘤发生 

分 类 号：Q555.7[生物学—生物化学]