FIGURE 6.

As₄S₄ downregulated the PD‐L1 expression through p53/miR‐34a‐5p axis. (a) Effect of As₄S₄ (1.5 μM) on p53 and PD‐L1 protein expression in A549/DDP cells in the presence or absence of PFT‐α (30 μM) treated for 48 h. (b) p53 protein quantification of the western blot results in A549/DDP cells treated with As₄S₄, PFT‐α or their combinations for 48 h. Protein levels were normalized to the GAPDH levels and are shown as fold increase or decrease relative to the levels for the control strain. (c) PD‐L1 protein quantification of the western blot results in A549/DDP cells treated with As₄S₄, PFT‐α or their combination for 48 h. (d) Flow cytometric analysis showing apoptosis in A549/DDP cells treated by DDP (8 μM), DDP plus As₄S₄ (1.5 μM), or PFT (30 μM), or the combinations. (e) Apoptotic rate in each group. (f) miR‐34a‐5p levels in A549/DDP cells treated with As₄S₄, PFT‐α or their combination for 48 h. Data represents the mean ± SD of three independent experiments (*p < 0.05; **p < 0.01; ***p < 0.001). PFT‐α, Pifithrin‐α