Résumé
Purpose:The objective of the study is to investigate the pattern of apoptosis and to explore the effect of Fas/FasL on the process of apoptosis induced by daunorubicin (DNR) on human myeloid leukemia cell line HL 60.Methods:The effect on apoptosis and the expression of Fas and FasL antigen induced by DNR on cell line HL 60 were measured by fluorescence microscope ,DNA electrophoresis and flow cytometry analysis.Results:DNR could induce typical apoptosis of HL 60 cells with the DNR plating concentration at 0.1,1 ?g/ml after 6 hours. Morphological changes such as apoptosis bodies, chromatic condensation and cytoplasm budding were observed by fluorescence microscope. Sub G 1 peaks was found by flow cytometry. HL 60 cell apoptosis rate reached a peak at 24 hours. Sub G 1 peaks were not found by flow cytometry with the DNR plating concentration at 10 ?g/ml after 6 hours. DNR could upregulate the expression of Fas and FasL of HL 60 cells.Conclusions:Apoptosis induced by DNR is one of the primary mechanisms in chemotherapy. Fas/FasL system participate in the apoptosis induced by DNR .
Résumé
The effects of 1, 25 (OH)2D3 in combination with low-dose chemotherapeutant on the human promyelocytic leukemic cells (HL-60) were investigated. In 4-day-cultured cells, 1, 25 (OH)2D3 and low-dose harringtonine (HH) or daunorubicine (DNR) had synergic effect in inducing differentiation of HL-60 cells, and HH or DNR significantly potentiated the effect of 1, 25 (OH)2D3 in inhibiting the cell proliferation, which were demonstrated by NBT reduction test and [3H]-TdR incorporation, respectively. Cell cycle analysis by flow cytometery revealed that the cells in S phase decreased remarkably and most cells stopped at G0/G1 phase. The results provide a new way for the inducers in treatment of leukemia.