RESUMEN
OBJECTIVE: To investigate the effects of ferulic acid (FA) on proliferation, apoptosis and Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) signaling pathway of human acute myeloid leukemia (AML) U937 cells. METHODS: Different concentrations of FA (0ã10ã25ã50ã100ã200 µmol/L) was used to treat human AML cell lines Kasumi-1, HL-60, and U937 cells respectively for 24 h. The cell survival rate was detected by cell counting kit-8 method, and the 50% inhibitory concentration (IC50) of each cell line was calculated. The U937 cells were divided into control group, FA group (50 µmol/L FA), FA+pcDNA group (50 µmol/L FA+transfected with empty plasmid), FA+pcDNA-TLR4 group (50 µmol/L FA+transfected with TLR4 overexpression plasmid). Flow cytometry was used to detect U937 cell cycle and cell apoptosis; plate clone formation test was used to detect U937 cell clone formation ability; fluorescence quantitative PCR was used to detect the TLR4, NF-κB p65 mRNA levels in U937 cells; Western blot was used to detect the expression levels of CyclinD1, CyclinE, Bcl-2 related X protein (Bax), B cell lymphoma-2 (Bcl-2), Caspase-3, TLR4, and NF-κB p65 protein in U937 cells. RESULTS: With the increase of FA concentration, the survival rates of Kasumi-1, HL-60 and U937 cells gradually decreased(r=-0.919, r=-0.909, r=-0.900), the IC50 of U937 cells was 50.25±2.23 µmol/L. Compared with the control group, after drug treatment of U937 cells, the ratio of G0/G1 phase cells, apoptosis rate, expression levels of Bax and Caspase-3 proteins in FA group were significantly increased (P<0.05), the number of cell clones, the ratios of S phase and G2/M phase cells, expression levels of CyclinD1, CyclinE and Bcl-2 proteins, and TLR4, NF-κB p65 mRNA and protein were significantly decreased (P<0.05); compared with FA group and FA+pcDNA group, the ratio of G0/G1 phase cells, apoptosis rate, expression levels of Bax and Caspase-3 proteins in FA+pcDNA-TLR4 group were significantly decreased (P<0.05), the number of cell clones, the ratios of S phase and G2/M phase cells, expression levels of expression levels of CyclinD1, CyclinE and Bcl-2 proteins, and TLR4, NF-κB p65 mRNA and proteins were significantly increased (P<0.05). CONCLUSION: FA inhibits U937 cell proliferation and promotes cell apoptosis by inhibiting the TLR4/NF-κB signaling pathway.
