Fig. 5

Berberine induces autophagy via ERK signaling inhibition. a and b Total and phosphorylation ERK was analyzed by western blotting in parental and TMZ resistance cells. c and d TMZ-R U87 and U251 cells were transfected with GFP-LC3 with or without ERK1 plasmid, followed by treatment with 100 μM TMZ with 10 μM berberine for 24 h. The numbers of GFP-LC3 puncta were quantified with confocal microscopy. e and f TMZ-R U87 and U251 cells were transfected with ERK1 plasmid, followed by treatment with 100 μM TMZ with 10 μM berberine for 24 h. Indicated proteins level were analyzed by western blotting. LC3 II was normalized to LC3 I. g IP experiment was performed with antibody against Bcl-2 in berberine-treated TMZ-R cells. Then the Beclin1 was analyzed by western blotting. BBR: berberine. Results were presented as means ± SD from three independent experiments. *, P < 0.05