NPM1基因突变表达对THP-1白血病细胞增殖和凋亡的作用探讨

 摘要：目的 探讨核仁磷酸蛋白（NPM1）基因突变对白血病细胞增殖潜能和凋亡发生的影响。方法 将携带NPM1 A型突变（NPM1 mA）的重组质粒载体pEGFPC1-NPM1 mA转染白血病THP-1细胞系，构建稳定表达NPM1 A型突变蛋白的白血病细胞株(THP-1 mA)，同时设立未处理组（THP-1）和空载体转染组（THP-1 C1）作为对照。通过MTT试验观察细胞体外增殖能力，流式细胞术分析细胞周期分布及凋亡发生率的改变；采用RT-PCR和Western blot分别检测细胞凋亡相关蛋白（Bax和Bcl-2）mRNA及蛋白表达水平。结果 与未处理组和空载体转染组细胞相比较，携NPM1突变体的THP-1 mA细胞体外增殖能力明显增强，S期细胞比例明显增高，G1期细胞比例显著减低；而NPM1突变体转染后THP-1细胞的凋亡率没有显著变化，同时细胞凋亡相关蛋白Bax, Bcl-2的mRNA和蛋白表达以及Bax/Bcl-2比值亦未见明显改变。结论 NPM1突变基因能够促进白血病细胞的体外增殖能力，而对白血病细胞凋亡无显著影响，这为进一步阐明NPM1突变与AML的关系提供了新的科学依据。

Effects of overexpression nucleophosmin(NPM1) mutations on the proliferation and apoptosis of THP-1 leukemic cells

Objective To investigate the effect of Nucleophosmin（NPM1） mutations on the proliferation and apoptosis of leukemia cells.Methods The pEGFPC1-NPM1 mA plasmid vector was transfected into THP-1 cells to establish the stably expressed NPM1 mutation A protein leukemia cells（THP-1 mA）.The cells transfected with pEGFPC1 plasmid（THP-1 C1） and the untreated cells（THP-1） were set as control.Cells proliferation potential was assessed by MTT assay;flow cytometry was used to detect the cell cycle and cellular apoptosis.The mRNA and protein expression of BAX and BCL-2 were analyzed by RT-PCR and Western blot,respectively.Results Compared with the controls,growth ability of THP-1 mA cells was significantly improved（P<0.05）.Additionally,the percentage of cells in the S phase increased significantly and that in the G₁ remarkably decreased（P<0.05）.While there was no significantly change on cellular apoptosis and the expression of BAX and BCL-2 on the mRNAlevel or protein level.The ratio of BAX/BCL-2 also had no significantly change.Conclusions NPM1 mutations may promote cells proliferation potential in vitro,but had no significantly influence on cellular apoptosis.