沉默Bmi-1表达对K562/ADM细胞体内外增殖能力的影响

Effect of Bmi-1 Silencing on the Proliferation of K562/ADM Cells in vitro and in vivo

目的:观察沉默Bmi-1表达对慢性髓系白血病阿霉素耐药细胞株-K562/ADM细胞增殖的影响并初步探讨其分子机制。方法:将Bmi-1小干扰RNA(siRNA)序列转染到K562/ADM细胞中降低其Bmi-1的表达;采用MTT法、软琼脂集落形成实验、裸鼠成瘤实验检测沉默Bmi-1表达对K562/ADM细胞体内外增殖能力的影响;应用Western blot检测Bmi-1、PTEN、p-AKT等蛋白表达;免疫组织化学实验分析Bmi-1和Ki-67的表达情况。结果:Bmi-1基因的沉默能够抑制K562/ADM细胞的增殖活性、集落形成及裸鼠成瘤能力;Bmi-1基因沉默后,干扰组PTEN表达明显升高,而p-AKT活性明显下降;p-AKT抑制剂-LY294002处理K562/ADM细胞后,p-AKT表达降低,集落形成及裸鼠成瘤能力相比K562/ADM细胞降低;PTEN抑制剂-Bpv处理K562/ADM-S1细胞后,PTEN的表达降低,而p-AKT表达、集落形成及裸鼠成瘤能力得以重塑;Bmi-1基因沉默使得肿瘤组织中Bmi-1与Ki-67表达均下降。结论:Bmi-1基因有可能参与了对K562/ADM的体内外增殖能力的调控,PTEN/pAKT信号通路可能涉及其中。

Objective:To investigate the effect of Bmi-1 gene silencing on the proliferation of K562/ADM cells in vitro and in vivo and to explore its possible molecular mechanism.Methods:The small interference RNA(siRNA)sequences of Bmi-1 were transfected into K562/ADM cells for decreasing the expression of Bmi-1.The effect of Bmi-1 silencing on the proliferation of K562/ADM cells in vitro and in vivo was detected by using MTT method,cell colony-forming test and tumoriganicity of nude mice;the expression of Bmi-1,PTEN and PAKT proteins was detected by Wertern blot.The immunohistochemistry assay was used to analyze the expression of Bmi-1 and Ki-67.Results:The Bmi-1 silencing could significantly inhibit the proliferation activity of K562/ADM cells,the cell colony-forming ability and tumorigenicity were reduced.LY294002 decreased p-AKT expression,cell colony-forming ability and tumorigenicity.Bpv reduced the PTEN expression but increased p-AKT expression and restored the colony-forming ability and tumorigenesis of K562/ADM-S1-Bpv cells.Bmi-1-siRNA dramatically suppressed the Bmi-1 and Ki-67 protein levels in xenograft tumor tissue.Conclusion:Bmi-1 can mediate the proliferation of K562/ADM cell,the PTEN/p-AKT might be involved in this pathway.