WISp39基因对U937细胞增殖、凋亡和周期的影响

为了探讨一种新发现的p21调控蛋白WISp39对白血病细胞的增殖、凋亡和周期的影响,构建了WISp39的真核表达质粒pLenti6/V5-WISp39,并导入了人髓系白血病细胞系U937细胞,转染后用定量PCR检测了WISp39表达的变化,用CCK-8法测定细胞增殖活性,流式细胞术（FACS）检测细胞凋亡和周期的变化。结果显示：pLen-ti6/V5-WISp39转染48小时后,实验组中WISp39mRNA表达上升了（5.5±1.2）倍,同时U937细胞的增殖明显受到抑制,抑制率为37.6%;进一步的分析表明,在实验时间内,WISp39表达的升高不能明显诱导U937细胞的凋亡,但G0/G1期细胞比例由（40.59±0.7）%上升到（49.79±1.1）%。结论：WISp39对于U937无明显的诱导凋亡作用,但通过对细胞周期的影响,使停滞在G/G期的细胞增多,从而抑制了U937增殖。

Effect of WISp39 on Proliferation, Cell Cycle and Apoptosis of U937 Cells

To investigate the effect of a novel p21-modulating protein WISp39 on proliferation, apoptosis and cell cycle of leukemia cells, the plasmid pLenti6/V5-WISp39 was constructed and transfected into the human myelocytic leukemia cell line-U937 cells. The expression of WISp39 was detected by real-time PCR at 48 hours after transfection, proliferation of U937 cells assayed by CCK-8, apoptosis and cell cycle were determined by flow cytometry. The results showed that plasmid pLenti6/V5-WISp39 could readily enhance the expression of WISp39 in U937 cells. A significant growth inhibition (37.6%) was observed in cells tranfected with pLenti6/V5-WISp39, while the control plasmid pLenti6/V5-lacZ showed little effect on U937 growth. Further analysis revealed that pLenti6/V5-WISp39 did not show obvious apoptosis induction effect, but it could really regulate U937 proliferation via cell cycle modulation. Compared with pLenti6/V5-lacZ, pLenti6/V5-WISp39 resulted in increase of cells in G(0)/G(1) phase by 10% at 48 hours after transfection. It is concluded that the WISp39 gene has no significant apoptosis induction effect on leukemic cells, but it can increase cells at G(0)/G(1) phase via effect on cell cycle, thus inhibiting the U937 proliferation. This result means WISp39 gene can act as a negative modulator on tumour cells.