Blocking NF-κB nuclear translocation leads to p53-related autophagy activation and cell apoptosis

Figure 1 Blocking nuclear factor-κB nuclear translocation activates autophagy and induces cell apoptosis. A: Western blotting analysis of the nuclear p65 in the control and SN50-treated SGC7901 cells. Western blotting analysis was used to detect the nuclear protein levels of p65 after SN50 treatment for 6-24 h. SGC7901 cells were treated with SN50 (18 μmol/L) at various time points and were harvested for nuclear p65 protein levels. It indicates that SN50 may down-regulate the expression of nuclear p65. Values were given as mean ± SE. Statistical comparisons were carried out with Dennett’s test. ^aP < 0.05 and ^bP < 0.01 vs control (n = 3); B: Autophagy was activated after SN50 treatment. SGC7901 cells were incubated with SN50 (18 μmol/L) and stained with MDC (100 μmol/L). Fluorescence particles indicate L-AVs. (a) control, (b) 6 h, (c) 12 h, (d) 24 h after SN50 treatment (× 1000) (n = 3); C: MAP1 LC3 expression and location in SGC7901 cells after treatment with SN50. Cells were treated with SN50 (18 μmol/L) for 6 h (b), 12 h (c) and 24 h (d), and observed under immunofluorence microscope. (a) Control (× 1000) (n = 3). SN50 increased the punctuate distribution of LC3 from 6 to 24 h; D: Western blotting analysis of the LC3 in the control and SN50-treated SGC7901 cells. Western blotting analysis was used to detect the protein levels of LC3 after SN50 treatment for 6-24 h. SGC7901 cells were treated with SN50 (18 μmol/L) and were harvested for total proteins. It indicates that SN50 may up-regulate the expression of LC3I and LC3II. SN50 increased the ratio of LC3II/LC3I. Values were given as mean ± SE. Statistical comparisons were carried out with Dennett’s test. ^aP < 0.05 vs control (n = 3); E: Western blotting analysis of the Beclin 1 in the control and SN50-treated SGC7901 cells. Western blotting analysis was used to detect the protein levels of Beclin 1 after SN50 treatment for 6-24 h. SGC7901 cells were treated with SN50 (18 μmol/L) and were harvested for total proteins. It indicates that SN50 may up-regulate the expression of Beclin 1. Values were given as mean ± SD. Statistical comparisons were carried out with Dennett’s test. ^bP < 0.01 vs control (n = 3); F: Hoechst 33258 staining showed apoptosis was induced after SN50 (18 μmol/L) treatment. SGC7901 cells were incubated with SN50 (18 μmol/L) and stained with Hoechst 33258 (10 mmol/L). Fluorescence particles showed apoptosis. (A) control, (B) 6 h, (C) 12 h, (D) 24 h after SN50 treatment (× 400) (n = 3).