Differentation And Apoptosis Induiced By Tanshinone ⅡA Combined With Arsenic Trioxide In NB4 Cells

ObjectiveTo evaluate the synergistic effects of Tanshinoneâ…¡A(Tanâ…¡A)combination with arsenic trioxide(As₂O₃) on differentiation and apoptosis of NB4 cells, a human acute promyelocytic leukemia(APL) cell line.MethodsThe NB4 cell are tr'eated with 1.0μg/ml Tanshinoneâ…¡A combined with 0.125μmol/L, 0.25μmol/L, 0.5μmol/L and 1.0μmol/L arsenic trioxide respectively. The proliferative inhibition rate of NB4 cell induce by Tanshinoneâ…¡A, arsenic trioxide and their combination were calculated on the fifth day. The morphology of cell differentiation were observed by Giemsa stain and transmission electron microscope(TEM).The cell cycle,proliferation index and apoptosis induice by these drugs were measured by flow cytometry(FCM).Results1. Combination treatment of Tanâ…¡A with As₂O₃ had synergistic effects on the proliferative inhibition of NB4 cells. This synergistic effects showed a dose and time-dependent manner. The proliferative inhibition rate of NB4 cells treated by 1.0μug/mL Tanâ…¡A for five days was (45.01±4.82) %, while the proliferative inhibition rate of NB4 cells treated by Tanâ…¡A combination with 0.125μmol/L, 0.25μmol/L and 0.5μmol/L As₂O₃ respectively were increased to (82.05±3.04) %, (94.06±0.95) %and (95.86±2.08) %,which was much higher than those be treated by corresponding As₂O₃ alone(p＜0.01).2. Combination treatment of Tanâ…¡A with As₂O₃ had synergistic effects on the apoptosis of NB4 cells. The apoptosis rate of NB4 cells treated by 1.0μug/mL Tanâ…¡A combined with 0.5μmol/L and 1.0μmol/L As₂O₃ respectively for one day were (4.20±0.36) % and (20.17±2.15) %, while this rate was only (1.67±0.67) % and (9.43±0.51) % when treated by corresponding 0.5μmol/L and 1.0μmol/L As₂O₃ alone. (p＜0.05) The synergistic effects of 1.0μug/mL Tanâ…¡A combined with 0. 5μmol/L As₂O₃ on the apoptosis of NB4 cells lasted for 72 hours.3. Combination treatment of Tanâ…¡A with As₂O₃ had synergistic inhibition effects on proliferation index(PI) of NB4 cells presented with decrease cells in S phase and increase cells in GO or G1 phase. When treated by 1.0μug/mL Tanâ…¡A combined with 0.125μmol/L,0. 25μmol/L and 0. 5μmol/L As₂O₃ respectively, the PI of NB4 cells were (33.40±1.01) %, (33.73±1.72) % and (32.93±4.32) %,which were lower than those treated by corresponding As₂O₃ alone. (p＜0. 05)4. Combination treatment of Tanâ…¡A with As₂O₃ had no significant synergistic effects on differentiation of NB4 cells.Conclusion:1 Combination treatment of Tanâ…¡A with As₂O₃ has significant synergistic effects on the apoptosis of NB4 cells. This synergistic effects of Tanâ…¡A combination with As₂O₃ is related with the dosage of the As₂O₃to be combined with.2 The significant synergistic effects of the combination with Tanâ…¡A and As₂O₃ is not demonstrated in our experiment.