A study on the apoptosis in HL-60 cells induced by cyclosporine A

AIM:To investigate if cyclosporine A(CsA) induces the apoptosis in HL-60 cells.METHODS:Apoptosis was measured by the morphology of apoptotic cells,the quantitation of DNA fragmentation with the diphenylamine reaction,the agarose-gel electrophoresis of DNA fragment,and flow cytometric analysis.RESULTS:When the cells were incubated with CsA 50 mg/L for 4h, the percentage of DNA fragmentation increased to (28.2±5 8)% compared to the control group (12.5±1 7)% without CsA ( P 0 01, n =10).Chromatin condensation,nuclear fragmentation and production of apoptotic bodies were seen in the cells treated with CsA utilizing light and electron microscopy.DNA electrophoresis of CsA-treated HL-60 cells showed nuclear fragmentation in oligonucleosomal fragments (DNA ladder).Flow cytometric analysis revealed that the percentage of apoptotic cells was 49.7% and 9.1% after the cells were incubated with or without CsA 50 mg/L respectively.Induction of DNA fragmentation by CsA was both dose-and-time dependent.CONCLUSION:CsA can induce apoptosis in HL-60 cells.