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

Figure 3 P53 inhibitor blocks SN50-induced autophagy activation and cell apoptosis. A: Effects of p53 inhibitor Pifithrin (Pft)-α on SN50-induced P53 upregulated modulator of apoptosis (PUMA) expression of SGC7901 cells. SGC7901 cells were pretreated with Pft-α (30 μmol/L) 6 h before SN50 (18 μmol/L). Protein expression was evaluated by Western blotting at 24 h. Results were presented as mean ± SD of three independent experiments. ^aP < 0.05 and ^bP < 0.01 vs control group; B: Effects of p53 inhibitor Pft-α on SN50-induced damage-regulated autophagy modulator (DRAM) expression of SGC7901 cells. SGC7901 cells were pretreated with Pft-α (30 μmol/L) 6 h before SN50 (18 μmol/L). Protein expression was evaluated by Western blotting at 24 h. Results were presented as mean ± SD of three independent experiments. ^aP < 0.05 and ^bP < 0.01 vs control group; C: Effects of p53 inhibitor Pft-α on SN50-induced LC3 expression of SGC7901 cells. SGC7901 cells were pretreated with Pft-α (30 μmol/L) 6 h before SN50 (18 μmol/L). Protein expression was evaluated by Western blotting at 24 h. Results were presented as mean ± SD of three independent experiments. ^aP < 0.05 vs control group; D: Effects of p53 inhibitor Pft-α on SN50-induced Beclin 1 expression of SGC7901 cells. SGC7901 cells were pretreated with Pft-α (30 μmol/L) 6 h before SN50 (18 μmol/L). Protein expression was evaluated by Western blotting at 24 h. Results were presented as mean ± SD of three independent experiments. ^aP < 0.05 and ^bP < 0.01 vs control; E: Reduced viability of SGC7901 cells after SN50 treatment. SGC7901 cells (7 × 10⁴ cells/mL) were cultured with 18 μmol/L of SN50 and cell viability was analyzed by MTT assay. MTT assays revealed that the inhibition rate reached 25.31% ± 4.13%, 34.19% ± 2.06%, 44.79% ± 1.65% after treatment of SN50 (18 μmol/L) 24,48 and 72 h. Values were given as mean ± SD of three independent experiments. ^aP < 0.05 and vs control; F: P53 inhibitor may attenuate the inhibitory effects of SN50-induced death of SGC7901 cells. SGC7901 cells were pretreated with Pft-α (30 μmol/L) 6 h before SN50 treatment (18 μmol/L). Cell viability was evaluated by MTT assay at 24, 48 and 72 h. Results were presented as mean ± SD of three independent experiments. ^aP < 0.05 vs control, ^bP < 0.01 compared with SN50 alone treated group; G: Flow cytometric analysis of mitochondria membrane potential in the control and SN50-treated SGC7901 cells. Cells were treated with SN50 (18 μmol/L) for 6, 12 and 24 h and were stained with JC-1 (5 μmol/L) for 30 min. Values were given as mean ± SD. Statistical analysis was carried out with ANOVA followed by Dunnett’s t test. ^aP < 0.05 vs control.