Fig. 7.

E2 increases the basal activation of cPLA₂ in SKBR3 cells, acting through GPR30-mediated EGFR trans-activation. A–C, Western blot analysis of phospho-cPLA₂α (Ser505) and total cPLA₂ was performed on SKBR3 cells treated with either vehicle (0) or E2 (10 nm), with or without CRM197 (200 ng/ml) at the indicated time points (A); treated with vehicle (0) or E2 (10 nm), with or without AG825 (5 μm) for 10 min (B); or treated with vehicle (C) or E2 (10 nm) or ICI (10 mm) or the GPR30-selective agonist G1 (100 nm) for 10 min (C). A line separates noncontiguous lanes on the same gel. Data are mean values ± se. **, P < 0.01 compared with vehicle-treated control; *, P < 0.01 compared with E2-stimulated values at corresponding time point. D, Western blot analysis of phospho-ERK1/2 MAPK (Thr202/Tyr204) and total ERK1/2 MAPK was performed on SKBR3 cells treated with either vehicle (0) or E₂ (10 nm), with or without CRM197 (200 ng/ml) at the indicated time points. Total cPLA₂α or ERK1/2 was used for protein level normalization as appropriate.