重楼皂苷D对人慢性粒细胞白血病K562细胞增殖的抑制作用及其机制

目的 探讨重楼皂苷D对人慢性粒细胞白血病细胞株K562增殖的抑制作用及其机制.方法 选用浓度为0、0.1、0.2、0.4、0.8、1.2、2.4μmol/L重楼皂苷D作用于K562细胞24 h,用CCK-8法检测重楼皂苷D对K562细胞增殖的抑制作用;流式细胞术检测重楼皂苷D对K562细胞凋亡以及细胞周期分布的影响;Western blot方法检测相关蛋白的表达.结果 重楼皂苷D可显著抑制K562细胞增殖,24 h的半数有效抑制浓度(IC50)为(0.9±0.1)μmol/L.流式细胞术检测结果显示,浓度为0.9μmol/L重楼皂苷D作用于K562细胞12、24 h后,细胞早期凋亡率较对照组的(2.05±0.45)%分别提高到(11.46±1.51)%、(28.87±2.35)%,差异有统计学意义(F=38.637,P<0.05).重楼皂苷D能够显著下调bcl-2、CDK1、cyclin B1、bcr-abl融合蛋白的表达,上调Bax、细胞色素C、活化的caspase-3以及p21的表达(均P<0.05).此外,重楼皂苷D能够将细胞周期阻滞在G2/M期(F=42.355,P<0.05).结论 重楼皂苷D能够明显抑制慢性粒细胞白血病K562细胞增殖,其作用机制可能是诱导细胞凋亡及促进细胞周期阻滞.

Inhibitory effect of polyphyllin D on the proliferation of human chronic myelogenous leukemia cell line K562 and its mechanism

Objective To explore the inhibitory effect of polyphyllin D on the proliferation of human chronic myelogenous leukemia (CML) cell line K562 and its mechanism. Methods K562 cells were treated with various concentrations of polyphyllin D (0, 0.1, 0.2, 0.4, 0.8, 1.2, 2.4 μmol/L) at 24 h, and cell viability was assessed by CCK-8 assay. Flow cytometry was used to detect the effect of polyphyllin D on the apoptosis, and the cell cycle arrest of K562 cells. The relative proteins were analyzed by using Western blot. Results The polyphyllin D could significantly inhibit the proliferation of K562 cells, and the effective inhibitory concentration (IC50) was (0.9 ± 0.1) μmol/L at 24 h. The results of flow cytometry showed that after treatment with 0.9 μmol/L polyphyllin D at 12 h and 24 h, the apoptotic rate of the cells [(11.46 ±1.51) %, (28.87 ± 2.35) %] were significantly higher than that of the control group [(2.05±0.45) %], and the difference was statistically significant (F= 38.637, P< 0.05). The expressions of bcl-2, CDK1, CyclinB1 and bcr-abl fusion protein were down-regulated by polyphyllin D, and the expressions of Bax, cytochrome C, activated caspase-3 and p21 were up-regulated (all P<0.05). In addition, polyphyllin D could arrest cell-cycle at G2/M phase (F=42.355, P<0.05). Conclusion Polyphyllin D can significantly inhibit the proliferation of human CML cell line K562, and its mechanism could play a role by inducing apoptosis and promoting cell cycle arrest.