EGF up-regulates GPR30 expression in SkBr3 cells. A, The expression of GPR30 was evaluated by semiquantitative RT-PCR in cells treated for 1 h with vehicle (−) or 50 ng/ml EGF alone and in combination with 10 μm EGFR inhibitor tyrphostin AG, 10 μm MEK inhibitor PD, 10 μm Src family tyrosine kinase inhibitor PP2, 10 μm PKA inhibitor H89, 10 μm PI3K inhibitor LY, as indicated. The housekeeping gene 36B4 was determined as a control. B, Quantitative representation of GPR30 mRNA expression (mean ± sd) of three independent experiments after densitometry and correction for 36B4 expression. ○, P < 0.05, for cells receiving vehicle (−) vs. treatment. C, Immunoblot of GPR30 from SkBr3 cells treated for 2 h with vehicle (−) or 50 ng/ml EGF alone and in combination with 10 μm AG, 10 μm PD, 10 μm PP2, 10 μm H89, and 10 μm LY, as indicated. β-Actin served as a loading control.