Aspirin Inhibits Proliferation And Induces Apoptosis On Human Myeloid Leukemia Cell Line HL-60

Objective : To use human myeloid leukemia cell line HL-60 as an experimental model, to research the effect of nonsteroidal antiinflammatory drugs (aspirin) on the growth of HL-60 cell.Methods : By using typan blue exclusion test , to calculate the numbers of living cells . Inhibition rate was tested by MTT method. Apoptosis induced by ASA in HL-60 cells was investigated by applying light microscopy DNA electrophoresis and flow cytometry analysis techniques .Cell cycle was determined with flow cytometry analysis. Immunocytochemical staining and RT-PCR method were used to examine c-myc protein and mRNA expression.Results : (l)When treated with 2.5-10.0mM/L ASA for 72h,thepercentage of inhibition rate increased with the dose-dependent manner. The means IC50 value for HL-60 cells was 8.97mM/L . There was the synergetic effect between 2.5mM/L ASA and 100ug/L Ara-c. (2) When treated with 2.5-10.0mM/L ASA for 72h, the percentage of apoptotic HL-60 cells increased with the dose increasing extending ; Under light microscope , a typical morphological change of apoptosis was observed and DNA ladder of typical apoptosis was found by gelose electrophoresis; typical subdiploid apoptosis peaks were detected by flow cytometry analysis.(3)After HL-60 cells were treated with ASA, the results of flow cytometry analysis : for phases of cell cycle, the S phase ratio were increased significantly and GO/G1 phase ratio were decreased (4) When treated with 2.5mM/L ASA for 12h ,c-myc protein and mRNA were downregulated.Conclusions : To a certain dosage of ASA can suppress the proliferation and induce apoptosis of HL-60 cells in a dose dependent manner .The mechanism of ASA inducing apoptosis may be related to disturb cell cycle and downregulation expression of c-myc mRNAo...