RESUMEN
AIM: To investigate the mechanism of baicalin-induced apoptosis in human laryngeal cancer cells. METHODS: AMC-HN-8 cells were selected for the study, and baicalin was applied to the cells at different concentrations (0, 10, 30, 100, and 300 μmol/L), and the half-inhibitory concentration (IC50) was measured by the CCK-8 method. Bax, cleaved-caspase-3, Cyto-c, IRF4 protein expression by protein blotting (Western blot); miR-125b-5p and IRF4 expression by RT-qPCR. Dual-luciferase reporter gene validation of Targetscan prediction (binding of miR-125b-5p to IRF4-3'UTR); apoptosis and necrosis inhibitors explore the way baicalein induces death in laryngeal cancer cells. AMC-HN-8 was then divided into blank group, baicalein (IC50), miR-125b-5p inhibitor group, baicalein + inhibitor NC group, baicalein+miR-125b-5p inhibitor group, and cell invasion and clone formation assays to detect cell invasion and proliferation ability, respectively. Apoptosis was detected by flow cytometry. RESULTS: Baicalein inhibited the proliferation of AMC-HN-8 cells in a dose-dependent manner with an IC50 value of 47.31 μmol/L. Compared with the blank group, 47.31 μmol/L baicalin induced apoptosis and inhibited cell invasion, while upregulating the expression of miR-125b-5p and suppressing the mRNA and protein levels of IRF4. The luciferase results showed that the miR-125b-5p mimic was able to inhibit the activity of the IRF4-3'UTR promoter relative to the NC mimic (mimic) group. Baicalein induces laryngeal cancer cell death in an apoptotic manner. In addition, the combination of 47.31 μmol/L baicalin and miR-125b-5p inhibitor affected the behavior of AMC-HN-8 cells, showing that compared with the blank group, the baicalin group showed a decrease in the number of cell clones, weakened invasion ability, and increased apoptosis; the miR - 125b-5p inhibitor group showed an increase in the number of cell clones, enhanced invasion ability and decreased apoptosis. The baicalin+ inhibitor NC group was consistent with baicalin, with no significant effect of inhibitor NC on cell behavior. The cloning, invasion, and apoptosis of cells in the baicalin+miR-125b-5p inhibitor group were intermediate between the baicalin and miR-125b-5p inhibitor groups. CONCLUSION: Baicalin inhibits the proliferation of AMC-HN-8 cells, and the mechanism may be related to miR-125b-5p targeting to inhibit the expression of IRF4, inducing the pro-apoptotic proteins Bax, cleaved-caspase3, and Cyto-c, and inhibiting the apoptosis suppressor protein Bcl-2 thereby inducing apoptosis.