Figure 2

Effect of fulvestrant on erbB3/4 expression and activity in MCF-7, T47D, BT474 and MDAMB361 cells. (A) Western blots showing erbB3 and erbB4 protein expression in MCF-7, T47D, BT474 and MDAMB361 cells maintained in phenol red-free RPMI medium containing 5% foetal calf serum. (B) Reverse transcriptase polymerase chain reaction (RT-PCR) analysis of erbB3 and erbB4 mRNA expression. (C) Western blot analysis of total and phosphorylated erbB3, erbB4, AKT and extracellular signal-regulated kinases 1 and 2 (ERK1/2) protein expression in MCF-7, T47D, BT474 and MDAMB361 cells prior to and following treatment with fulvestrant (100 nM) for seven days. β-actin was used as a loading control (not shown for RT-PCR).