Naphthoquinone Derivative PPE8 Induces Endoplasmic Reticulum Stress in p53 Null H1299 Cells

Figure 4

H1299 cells were treated without or with (a) 5 μM PPE8 for indicated time. (b) Quantification of p-IRE of 4 independent experiments. The signal detected in untreated cells was taken as control of each experiment. Bars represented mean ± SD and expressed as a fold increase from control. Asterisks indicate the values that are significantly different from corresponding control (). (c) H1299 cells were treated with indicated concentrations of PPE8 for 2 h. The cell lysates were processed for western blotting to examine phosphorylated IRE1 with p-IRE1 antibody. (d) H1299 cells were treated without or with 5 μM PPE8 for 2 h. The lysates were immunoprecipitated with ASK1 antibody. The eluted protein was processed for western blotting to examine IRE1 with IRE1 antibody. Similar results were obtained in three independent experiments.

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