Role of BCL-2, caspase-3 and NF-κB in astragaloside inducing apoptosis of human NB4 cells / 中国实验血液学杂志

This study was purposed to investigate the apoptosis-inducing effect of astragalosides on acute promyelocytic leukemia(APL) cell line NB4 and its mechanism. NB4 cells were treated with different concentrations (200, 300, 400 µg /ml) of astragalosides for 48 h. The cell proliferation was assayed by using CCK-8 method; the cell apoptosis was analyzed by flow cytometry with Annexin V-FITE/PI double staining. The mRNA expression of BCL-2 and the relative activity of BCL-2, NF-κB and caspase-3 were detected by RT-PCR and Western blot, respectively. The results showed that after treated with astragalosides for 48 h, astragalosides inhibited NB4 cell proliferation in concentration-dependent way, the apoptosis rate of NB4 cells gradually elevated from 4.69% to 40.85% with the increasing of astragalosides concentration. Simultaneously, the mRNA expression of BCL-2 was down-regulated, Western blot analysis showed that the protein expression levels of BCL-2 and NF-κB decreased after astragalosides treatment, while caspase-3 protein expression level increased. It is concluded that the molecular mechanism of the astragalosides-induced apoptosis in NB4 cells may be associated with down-regulation of the expression of BCL-2 and NF-κB, finally the relative activity of caspase-3 activated.

Mechanism of apoptosis in human leukemia NB4 cells induced by total astragalosides / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect of total astragalosides (TA) on proliferation and apoptosis in human leukemia NB4 cells in vitro.</p><p><b>METHODS</b>The NB4 cells were treated with TA at different concentrations for 48 h in culture. Growth inhibition rates were measured by CCK-8 method. Flow cytometry was used to explore the cell apoptosis and the activity of NF-κB and Akt during apoptosis.</p><p><b>RESULTS</b>TA at different concentrations (200, 400, 600, 800 mg/L) inhibited proliferation of NB4 cells in a dose-dependent manner (P < 0.05), and the inhibitory rates of TA on NB4 cells were (14.54 ± 3.20)%, (24.79 ± 3.98)%, (57.28 ± 4.71)% and (88.28 ± 4.65)%, respectively. In terms of the induction of apoptosis, there was a significant difference between the TA group and blank control [(1.80 ± 1.24)%, P < 0.05]. At TA doses of 200, 400 and 600 mg/L, the apoptotic rates of NB4 cells were (10.03 ± 3.31)%, (14.87 ± 3.65)%, (23.45 ± 1.90)%, respectively. Besides, TA induced apoptosis of NB4 cells in a dose-dependent manner in the groups of 200 mg/L, 400 mg/L, 600 mg/L (P < 0.05). But there was no significant difference in apoptotic rates between the groups of 800 mg/L and 600 mg/L [(23.45 ± 1.90)%, P > 0.05]. In the group of 800 mg/L, the necrotic cells increased highly and the necrotic rate reached (45.65 ± 3.16)%. After TA treatment of NB4 cells at different concentrations (200, 400, 600 mg/L), the expression of NF-κB protein was significantly decreased compared with that of the blank control (9.79 ± 0.95, P < 0.05), while Akt protein was not significantly decreased (P > 0.05).</p><p><b>CONCLUSION</b>TA can inhibit the growth of NB4 cells and induce apoptosis in NB4 cells through an Akt-independent NF-κB signaling pathway.</p>