Mechanism of cyclosporin A-induced apoptosis in K562 cell line

Objective: To investigate the effect of CsA on apoptosis of K562 cells and identify the mechanism of CsA-induced apoptosis in K562 cells.Methods: Apoptosis of K562 cells induced by CsA was studied by light microscopy and flow cytometry(FCM).The effect of CsA on the expression of Bcl-2 gene was detected by FCM.Results: 20 μmol/L CsA induced the apoptosis of K562 cells in culture for 24 hours,on examining with light microscopy apoptotic cells showed typical morphological change of apoptosis,apoptotic cells displayed apoptotic peak when measured by FCM.CsA arrested K562 cells at G0~G1 phase.The apoptosis rate was significantly higher in CsA-treated groups than that in the alcohol group(P0.01).The expression rate of Bcl-2 oncoprotein was significantly lower in CsA-treated groups than that in the alcohol group(P0.01) Conclusion: CsA can induce apoptosis in K562 cells by down-regulating Bcl-2 gene in protein level.