[Effect of Dehydrocostus Lactone on Proliferation of K562 Cells and Its Mechanism]

To explore the inhibitory effect of dehydrocostus lactone on the proliferation of human chronic myeloid leukemia K562 cells and the underlying mechanisms.

Cell viability was evaluated by CCK-8 assay. Flow cytometry was used to assess the effect of dehydrocostus lactone on the cell cycle and apoptosis of K562 cells. The levels of BCR/ABL-STATs-related molecules were analyzed by using Western blot.

The CCK-8 assay showed that dehydrocostus lactone at graded concentration of 4, 6, 8, 10, 12 μmol/L could significantly inhibit the proliferation of K562 cells after exposure for 24 h. The proliferation inhibition rate was (24.32±3.05%), (42.91±3.89%), (46.35±4.93%), (77.06±5.42%) and (89.04±4.25%) respectively, showing statistically significantly different from (2.08±0.27%) in the control (P＜0.05). Also, the treatment with 5 and 10 μmol/L of dehydrocostus lactone induced K562 cell apoptosis, the apoptotic rate of K562 cells was significantly higher than that the control group (P＜0.05), and up-regulated the expression level of BAX and p21. Furthermore, dehydrocostus lactone (5 and 10 μmol/L) also increased the percentage of cells in G2/M [(8.53±1.71)% to (17.42±2.72) and (31.79±4.38%)](P＜0.05). The study results also revealed that dehydrocostus lactone significantly inhibited the expression of BCR/ABL STAT3, STAT5, CyclinB1, CDK1 and BCL-2, and up-regulated the expression level of BAX and p21.

Dehydrocostus lactone can suppress the proliferation of K562 cells and induce the apoptosis of K562 cells through BCR/ABL-STAT signaling pathways.