Objective: To investigate the role of nucleophosmin (NPM) in the proliferation of chronic myeloid leukemia cells (K562 cells) and its mechanism by RNAi technology.
Methods: shRNA was used to inhibit the expression of NPM. The expression of NPM gene was detected by real-time quantitative PCR. The effect of inhibiting NPM gene on cell proliferation was detected by MTS assay. Change of cell cycle was detected by flow cytometry. Western blot was used to detect the expression of cell cycle-related proteins.
Results: The shRNA lentiviral vector targeting at NPM gene was successfully constructed and used to transfect the K562 cells. The results showed that compared with the control groups, suppression of NPM gene expression in K562 cells could inhibit the cell proliferation and decrease the cell colony formation. Moreover, interference of NPM gene could prolong G0/G1 phase and arrest cell cycle, which may be related to the down-regulation of NPM gene expression and activation of p21 protein expression, thereby inhibited the formation of CDK2/ Cyclin E complex.
Conclusion: Down-regulation of NPM gene expression in K562 cells can induce cell cycle arrest and inhibit cell proliferation.
题目: 下调NPM基因表达对慢性髓系白血病细胞株K562增殖的抑制作用研究.
目的: 运用RNA干扰技术抑制核仁磷酸蛋白（NPM）的表达，研究NPM基因在慢性髓系白血病细胞株（K562细胞）增殖中的作用及其机制.
方法: 采用shRNA抑制NPM的表达，应用实时荧光定量PCR技术检测NPM基因的表达，MTS法检测抑制NPM基因对细胞增殖能力的影响，流式细胞术检测细胞周期的改变，Western blot检测细胞周期相关蛋白的表达.
结果: 成功构建了针对NPM基因的shRNA慢病毒载体，并感染K562细胞。检测结果显示，与对照组相比较，抑制K562细胞NPM基因的表达可以抑制细胞的增殖，减少细胞集落形成。干扰NPM基因可使G0/G1期延长，细胞周期阻滞，这可能与下调NPM基因后激活p21蛋白的表达，进而抑制CDK2/ Cyclin E复合物形成有关.
结论: 下调K562细胞NPM基因的表达，可以通过诱导细胞周期阻滞抑制K562细胞的增殖.