Figure 3. Lycorine induces autophagy-associated apoptosis by targeting mitogen-activated protein kinase kinase 2 (MEK2). (A-B) HCT116 cells transfected with blank or MEK2 vectors were treated with or without lycorine, and western blotting was performed to investigate the changes in autophagy and apoptosis. GAPDH was used as a loading control. (C) The viability of HCT116 cells transfected with blank or MEK2 vectors in response to the indicated concentrations of lycorine was detected using the Cell Counting Kit-8 assay. (D) HCT116 cells were transfected with MEK2 shRNA and cultured in the presence of lycorine, and the change in autophagy was analyzed using transmission electron microscopy. Magnification: ×1700 (left), ×5000 (right). (E–F) MEK2-overexpressing or control HCT116 cells were treated with lycorine for 24 h and analyzed using annexin V/PI flow cytometry. The right lower quadrant represents early apoptosis. Data are presented as the mean ± SD of three independent experiments (*p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001).