[Molecular mechanism of SHI-1 cell apoptosis induced by puerariae radix flavones in vitro].

This study was purposed to explore the effects induced by puerariae radix flavones (PRF) on human acute myeloid leukemia SHI-1 cells, apoptosis induced by PRF in vitro and its molecular mechanism. SHI-1 cells were treated with PRF in various concentration, then the inhibitory effect of cell proliferation were detected by MTT method, the cell cycle was analyzed by flow cytometry, the mRNA expression levels of Caspase-3, Caspase-8, Caspase-9, Bcl-2 and MLL-AF6 were detected by real-time polymerase chain reaction (R-T PCR), the protein expression levels of MAPK, p-MAPK and NF-κB were assayed by Western blot, and the activity of MMP was analyzed by Gelatin zymography. The results indicated that the PRF could inhibit the proliferation of SHI-1 cells in a time-and dose-dependent manner, and the cell cycle was arrested in S phase. When SHI-1 cells were treated with 25, 50 and 75 µg/ml PRF respectively, mRNA levels of Caspase-3, Caspase-8 and Caspase-9 increased in a dose-dependent manner (P < 0.05), Bcl-2 mRNA decreased in a concentration-dependent manner (P > 0.05), and the mRNA level of fusion gene MLL-AF6 did not changed as compared with the control group. Different concentration of PRF was used to treat SHI-1 cells, the expression levels of intracellular JNK, p-JNK, P38 MAPK and p-P38 MAPK increased in the concentration-dependent manner (P < 0.01); the expression of p-ERK1/2 and NF-κB decreased in the concentration-dependent manner, and the activity of MMP-2 and MMP-9 in the cell supernatant did not change in each groups. It is concluded that a certain concentration of PRF can induce the apoptosis of SHI-1 cells in vitro, its molecular mechanism may be related to the activation of Caspase hydrolase, activation of MAPK, downregulation of NF-κB, Bcl-2 and other signal molecules. However, it seemed that all these effects are not relate with the MLL-AF6 fusion gene.