[Inhibitory Effect of Kaempferol on Proliferation of KG1a Cells and Its Mechanism].

OBJECTIVE: To investigate the effect of kaempferol on proliferation of acute myeloid leukemia (AML) KG1a cells and its mechanism. METHODS: Human AML KG1a cells in logarithmic growth stage were taken and set at 25, 50, 75 and 100 µg/ml kaempferol group, another normal control group (complete medium without drug) and solvent control group (add dimethyl sulfoxide) were also set. After 24 and 48 hours of intervention, the cell proliferation rate was detected by CCK-8 assay. In addition, interleukin-6 (IL-6) combined with kaempferol group (Plus 20 µg/l IL-6 and 75 µg/ml kaempferol) was set up, 48 hours after culture, the cell cycle and apoptosis of KG1a cells were detected by flow cytometry, the mitochondrial membrane potential (MMP) of KG1a cells was detected by MMP detection kit (JC-1 method), and the expression of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway related proteins in KG1a cells were detected by Western blot. RESULTS: The cell proliferation rate of 25, 50, 75 and 100 µg/ml kaempferol group decreased significantly (P<0.05), and with the increase of kaempferol dose (r24 h=-0.990, r48 h= -0.999), the cell proliferation rate decreased gradually (P<0.05). The inhibitory effect of 75 µg/ml kaempferol on cell proliferation reached half of effective dose after 48 hours of intervention. Compared with normal control group, the G0/G1 phase cell proportion and apoptosis rate of cells in 25, 50 and 75 µg/ml kaempferol group increased, while the S phase cell proportion, MMP, phosphorylated JAK2 (p-JAK2)/JAK2 and phosphorylated STAT3 (p-STAT3)/STAT3 protein expression decreased in a dose-dependent manner (r=0.998, 0.994, -0.996, -0.981, -0.997, -0.930). Compared with 75 µg/ml kaempferol group, the G0/G1 phase cell proportion and apoptosis rate of cells in IL-6 combined with kaempferol group decreased, while the S phase cell proportion, MMP, p-JAK2/JAK2 and p-STAT3/STAT3 protein expression increased significantly (P<0.05). CONCLUSION: Kaempferol can inhibit KG1a cell proliferation and induce KG1a cell apoptosis, its mechanism may be related to the inhibition of JAK2/STAT3 signal pathway.