塞来昔布对K562白血病细胞的细胞毒作用及与伊马替尼的协同效应

目的 研究塞来昔布（Celecoxib）对K562细胞增殖、早期凋亡的影响及Rb蛋白质（PRb）、P27^Kip蛋白质表达变化,观察Celecoxib和伊马替尼联用对K562细胞增殖抑制和凋亡诱导是否具有协同效应.方法将K562细胞用不同浓度的Celecoxib（0、10、20、40、80及160μmol/L）作用36 h,四甲基偶氮唑盐比色法（MTT法）测定细胞活力;磷脂结合蛋白Ⅴ分析检测K562细胞早期凋亡;Western印迹检测不同浓度Celecoxib对K562细胞PRb和P27^Kip蛋白质表达的影响;用40 μmol/L Celecoxib、0.2μmol/L伊马替尼分别或联合作用K562细胞,观察药物对细胞活力和凋亡诱导是否具有协同作用.结果Celecoxib能明显抑制细胞活力,并呈药物剂量依赖性：随着Celecoxib浓度增高,K562细胞凋亡百分率相应增高,在160μmol/L浓度,凋亡率达25.92%,蛋白质印迹结果显示,Celecoxib可使K562细胞PRb蛋白质表达呈浓度依赖性下调;P27^Kip蛋白质呈浓度依赖性上调.Celecoxib与伊马替尼联用,抑制K562细胞活力为对照组的27.68%.结论Celecoxib能以浓度依赖性方式抑制K562细胞增殖,诱导细胞凋亡;其抗增殖效应可能与PRb表达下调及P27^Kip表达上调有关.Celecoxib与伊马替尼联用,在抗白血病细胞增殖作用上具有显著的协同效应.

Cytotoxic activities of Celecoxib on leukemic cells and the synergistic effects of Celecoxib with Imatinib thereupon

OBJECTIVE: To explore the effects of Celecoxib on cell growth, early apoptosis, PRb and P27(Kip) protein expression of human leukemic cells of the line K562 and to determine its synergistic effects in combination of Imatinib. METHODS: K562 cel1s were incubated with Celecoxib of the concentrations of 0, 10, 20, 40, 80, and 160 micromol/L for 36 hours, the cell vitality was determined by MTT assay, the early apoptosis was examined by flow cytometry (FC). The percentage of annexin V positive was detected by FC so as to evaluate the early apoptosis. The expression of PRb and P27(Kip) protein was detected by Western blotting. Another K562 cells were incubated with Celecoxib of the concentration of 40 micromol/L, Imatinib of the concentration of 0.2 micromol/L, or Celecoxib 40 micromol/L + Imatinib 0.2 micromol/L for 36 hours. Then the cell vitality and early apoptosis of the cells were detected so as to evaluate the synergistic effects of the combination of Celecoxib and Imatinib. RESULTS: Celecoxib inhibited the K562 cells vitality significantly in a dose-dependent manner. The apoptotic rate of K562 cells was elevated with the increasing Celecoxib concentration. Celecoxib down-regulated the expression of PRb protein and up-regulated the expression of P27(Kip) protein in the K562 cells. The combination of Celecoxib and Imatinib exhibited evidently synergistic effects in terms of anti-proliferation on K562 cells. CONCLUSION: Celecoxib inhibits the proliferation and induces apoptosis on leukemic cells in a dose-dependent fashion. The anti-proliferation effect of Celecoxib may be associated with the down-regulation of PRb expression and up-regulation of P27(Kip) expression. Combination of Celecoxib and Imatinib has obviously synergistic effects in terms of anti-proliferation on K562 cells.