COMBINED EFFECT OF DECITABINE AND DOXORUBICIN ON PROLIFERATION AND DEGREE OF INVASION OF LEUKEMIC HL-60 CELLS

Meiling li1, 2, *, long li2, Haiyan ZHou3, Fuxue Meng2, Quanyi lu1, *

1Departments of Hematology, Zhongshan Hospital of Xiamen University, Xiamen, Fujian, 361004, China - 2Department of Hematology, The Third Affiliated Hospital of Guizhou Medical University, Duyun, Guizhou Province, 558000, China - 3Department of Clinical Research Centre, The Affiliated Hospital of Guizhou Medical University, Guiyang, Guizhou Province, 550004, China

Purpose: To investigate the combined effect of decitabine and doxorubicin on the proliferation and degree of invasion of leu- kemia HL-60 cells.

Methods: Human acute myeloid leukemia (HL-60) cells were used for this study. They were randomly divided into four groups: control group, decitabine group, doxorubicin group, decitabine + doxorubicin (DD) group. The cells were cultured in 10 % fetal bovine serum-supplemented RPMI 1640 culture medium. In the decitabine group, decitabin (5.0 μmol/L) was added to the culture medium, while doxorubicin (1.0 μmol/L) was added to the culture medium in the doxorubicin group. Decitabin (5.0 μmol/L) and doxorubicin (1.0 μmol/L) were added to the culture medium in the DD group. The extent of inhibition of cell proliferation was determined using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay kit. Apoptosis and cell cycle distribution of HL-60 cells were measured using a flow cytometer, while Transwell assay was used to determine the degree of invasion of the cells.

Results: Inhibition of cell proliferation were significantly higher in the decitabine and doxorubicin groups than in control group, and was significantly higher in DD group than in decitabine and doxorubicin groups (p<0.05). The inhibition increased with time across the groups (p<0.05). The extent of apoptosis was also significantly higher in the DD group than in decitabine and doxorubicin groups, and apoptosis increased with time across the groups (p < 0.05). There were more G0/G1 phase cells in the decitabine and doxo- rubicin groups than in control group, and G0/G1 phase cells were significantly higher in DD group than in decitabine and doxorubicin groups (p<0.05). There were fewer S phase cells in the decitabine and doxorubicin groups, and they were significantly lower in the DD group than in decitabine and doxorubicin groups (p<0.05). However, there were no significant differences in the distribution of cells in G2/M phase among the groups (p>0.05). Cells in the treatment groups showed less invasiveness, and the number of transmembrane cells were significantly reduced with time (p<0.05).

Conclusion: These results indicate that combination of DAC with doxorubicin produces synergistic and time-dependent inhibi- tion on the proliferation and invasion of HL-60 cells, thereby increasing the sensitivity of the cells to doxorubicin, arresting the cells at G0/G1 phase, and promoting apoptosis.