FIGURE 3.

Butaprost induced ERK1/2, Akt, and STAT3 phosphorylation. A, butaprost induced dose-dependent phosphorylation of ERK1/2, Akt, and STAT3. Mice were treated with butaprost (50 or 100 nmol) and sacrificed 2 h after treatment. B, butaprost (100 nmol) induced phosphorylation of ERK1/2, Akt, and STAT3 in a time-dependent manner. C, the Src and EGFR inhibitors suppressed butaprost-induced phosphorylation of ERK1/2, Akt, and STAT3. Mice were pretreated with PP2 (100 nmol) or AG1478 (100 nmol) for 30 min and then treated with 100 nmol of butaprost for 2 h. D, the EGFR inhibitor, gefitinib, suppressed butaprost-induced phosphorylation of EGFR, ERK1/2, Akt, and STAT3. Mice were pretreated with gefitinib (67 nmol) for 30 min and then treated with 100 nmol of butaprost for 2 h. EGFR was immunoprecipitated (IP) from skin lysates, and p-EGFR was determined by Western blot (WB) analysis by using a monoclonal anti-p-Tyr antibody. In A–D, the phosphorylation status was determined by Western blot analysis using antibodies against indicated proteins. The densitometry data are representative of two independent experiments. In A, C, and D, each lane represents an individual mouse. The number above each lane shows the mean -fold intensity from two mice.