The mechanisms of curcumin inhibiting the proliferation of HL-60 cells were investigated. Acute myeloid leukemic cell line HL-60 was studied by using cell culture, NBT reduction, SABC method measuring BrdU incorporation rate, FCM measuring DNA contents and TUNEL method determining apoptotic cell percentage. Curcumin inhibited proliferation of HL-60 cells in a dose- and time-dependent manner. When the HL-60 cells were treated with 25 μmol/L curcumin for 48 h, the inhibitory rate was 60. 71 % ± 1. 20 %. The study on BrdU incorporation rate and the distribution of DNA content and NBT reduction indicated that curcumin arrested. the cells in G2/M phase of cell cy cle at first, then in G0/G1 phase, the whole cell cycle progression was slowed down and DNA synthesis activities was halted. The arrested cells went to apoptosis instead of differentiation. The comparative study indicated that the ability of curcumin regulating the cell cycle of HL-60 cells was stronger than As2O3 and the acting points of curcumin were not completely consistent with those of VP-16. It was suggested that curcumin was able to regulate, to some extent, the G1/S and G2/M transmit checkpoints and disturb the HL-60 cell cycle to induce apoptosis.
To investigate the curcumin killing leukemia cellsin vitro,. Methods: The myeloid leukemic cell line HL-60 was studied by using cell culture, flow cytometrydetermining DNA content and TUNEL method measuring apoptotic cell percentage. Results: The data showed that curcumin selectively inhibited proliferation of acute myeloid leukemia (AML) HL-60 cell lines in a dose- and time-dependent manner. The growth inhibition rate was gradually increased and reached the peak at concentration of 25 (μmol/L curcumin at 24h. The sub-G, peak appeared after 12h treatment and was increased to 34.4% at 24h. The TUNEL method further certified that apoptotic cells reached 41% at the same phase. Conclusion: curcumin possesses obvious potent of anti-leukemia cell proliferation, which is contributed to the induction of HL-60 cells apoptosis. The concentration and action time of curcuminin vitro provide some reference for clinical use.
