Inhibitory effect of polyphyllin D on the proliferation of human chronic myelogenous leukemia cell line K562 and its mechanism / 白血病·淋巴瘤

ABSTRACT

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.