【摘要】 【目的】探讨抑癌基因PTEN对人慢性粒细胞白血病细胞系K562细胞周期的影响。【方法】将携带有野生型PTEN和绿色荧光蛋白的腺病毒(Ad-PTEN-GFP)及对照载体腺病毒(Ad-GFP)转染人慢性粒细胞白血病细胞系K562。MTT检测细胞增殖抑制率;流式细胞仪检测转染效率、细胞凋亡率和细胞周期的变化;荧光定量PCR(FQ-PCR)检测PTEN、CyclinD1、CyclinD2、CDK4、P27Kip1 mRNA水平变化,Western blot检测上述蛋白表达水平的变化。【结果】与Ad-GFP组比较,Ad-PTEN-GFP转染K562细胞后,细胞凋亡率最高为30%,细胞周期显示:G0/G1期细胞比例由54.9%增加至78.5%,G2/M期比例由30.2%降至13.6%,Cyclin D1、Cyclin D2、CDK4 mRNA及Cyclin D1蛋白表达降低,P27Kip1 mRNA及蛋白表达增加。【结论】PTEN基因高表达可以促进K562细胞凋亡,并通过抑制Cyclin D1、Cyclin D2、CDK4及增加P27Kip1表达使细胞周期阻滞在G0/G1期。更多还原

【Abstract】 【Objective】To investigate the effect of tumor suppressor wild type PTEN gene (phosphatase and tensin hemology deleted on chromosome ten gene) on the cell apoptosis and cell cycle of human chronic myeloid leukemia (CML) cell line K562 in vitro. 【Methods】 The recombination of wild type PTEN gene and adenovirus with green fluorescent protein (GFP) (Ad-PTEN- GFP) and control vector adenovirus (Ad-GFP) were transfected into K562 cell lines. The inhibitory rate of cell proliferation was detected by MTT assay and the transfection efficiency of Ad-PTEN-GFP, apoptosis rate and cell cycle were assessed by flow cytometry (FCM). The transcription changes of PTEN, Cyclin D1, Cyclin D2, CDK4, and P27Kip1 mRNA were measured by fluorescent quantitative PCR (FQ-PCR), and their protein levels were measured by Western blotting. 【Results】 Compared with transfected Ad-GFP, the highest apoptosis rate was 30% after transfected with Ad-PTEN-GFP in K562 cell lines. The ratio of G0/ G1 phase cells increased from 54.9% to 78.5% and reduced from 30.2% to 13.6% in G2/ M phase cells. Protein expression levels of Cyclin D1, Cyclin D2, CDK4 Mrna, and Cyclin D1 down-regulated and P27Kip1 mRNA and protein expression up-regulated after the cells transfected with PTEN gene. 【Conclusion】 Over expression of PTEN gene can promote the apoptosis of K562 cells in vitro and block cell cycle progression at G0 / G1 phase by down-regulating Cyclin D1, Cyclin D2, CDK4 expression and up- regulating P27 Kip1 expression.更多还原