Fig. 3

PB2 induces autophagy in gastric cancer cells. Cells were incubated with different concentrations of PB2 for 48 h. a Cells were stained with LC3 antibody or acridine orange (AO), and observed under a fluorescence microscopy (green, × 200). b Quantification of cells with LC3 dots. c Quantification of cells with AO staining. d Western blot shows the protein expression of autophagy-associated proteins, Beclin1 and Atg5. PB2 increases the mean relative levels of Beclin1 e and Atg5 f in SGC-7901 cells. Calculation of all these proteins were normalized to β-actin. g PB2-induced reduction in cell viability is reversed by 3-methyladenine (3-MA). SGC-7901 cells were treated as follow: Control, 3-MA (100 μM), PB2 (50 μM), 3-MA + PB2 for 48 h. Then, cell viability was measured by CCK-8 assay. *P < 0.05, **P < 0.01, ***P < 0.001 vs. control group. ##P < 0.01, vs. PB2 group