Objective To investigate the influence of β-catenin gene deletion on Stat-5α phosphorylation in bcr-abl induced leukemia cells. Methods The established conditonal hematopoitic β-catenin knockout mice were used to isolate bone marrow cells. Exogenous bcr-abl fusion gene was transduced to these bone marrow cells by retroviral infection with intent to transfom them to leukemia cells.Immunofluorescence was performed to detect the phosphorylation status of Stat-5α in both β-catenin deletion cells and control cells. bcr-abl transcription and protein levels were evaluated with real-time PCR and western blotting. Results Phosphorylation of Stat-5α was reduced significantly in β-catenin deletion leukemia cells on comparison with control cells despite that total Stat-5α protein showed no obvious changes. Total tyrosine phosphorylation and bcr-abl protein expression were reduced in bcr-abl induced β-catenin deletion CML cells,on the contrary, both of the reduction were not seen in bcr-abl induced β-catenin deletion ALL cells.Conclusion Loss of β-catenin inhibits both Stat-5α phosphorylationin and bcr-abl expression in bcr-abl induced leukemia cells.%目的 研究经bcr-abl诱导形成的白血病细胞中β-catenin缺失对Stat-5α蛋白磷酸化水平的影响.方法 利用已经建立的特异性骨髓造血系统β-catenin基因敲除小鼠,分离其骨髓细胞,应用逆病毒感染方法将外源性bcr-abl基因片段导入β-catenin缺失的骨髓细胞内,免疫荧光和Western blotting方法检测Stat-5 α蛋白磷酸化水平,应用real-time PCR及Western blotting分别检测β-catenin缺失细胞及对照细胞bcr-abl转录及蛋白表达.结果 与对照组相比,β-catenin缺失的白血病细胞Stat-5α磷酸化水平明显降低,而Stat-5α总蛋白量变化不明显;Western blotting结果显示β-catenin缺失的慢性髓细胞白血病(CML)细胞中酪氨酸磷酸化总水平及bcr-abl蛋白表达明显降低,而β-catenin缺失的急性淋巴细胞白血病(ALL)细胞中酪氨酸磷酸化总水平及bcr-abl蛋白表达无明显改变.结论 bcr-abl诱导形成的白血病转化细胞中,β-catenin缺失抑制bcr-abl蛋白表达及Stat-5 α磷酸化.
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