Figure 1

Paraffin-embedded breast cancer tissue immunostained with GPR30 or EGFR antibodies. The predominant staining pattern of GPR30 was cytoplasmic in carcinoma tissue, whereas EGFR was mainly expressed on plasma membrane (A). Cytoplasmic GPR30 immunostaining of breast tumors was (a) negative, (b) weak, (c) moderate or (d) strong. EGFR staining of breast tumors was (e) no staining, (f) moderate and complete staining, or (g) strong and complete staining. GPR30 moderately stained primary tumors (h), but strongly stained corresponding tissue during tamoxifen treatment (i). Quantitative (B) and paired (C) expression of GPR30 was compared in 53 matched tissues from primary tumors (PTs) and their corresponding metastases (MTs). Pair-wise scatter plots showed the correlation of GPR30 and EGFR expression in MTs (D). EGFR, epidermal growth factor receptor; GPR30, G-protein coupled receptor 30.