Figure 4
AEE788 enhances oestrogen receptor (ER) transcriptional activity. (A and B) Cell lines co-transfected with EREIItkLuc and pCH110 were treated with a standard 10 nM concentration of androstenedione and log10(M) increasing concentrations of 4-hydroxytamoxifen (4-OH) tamoxifen or letrozole in the absence or presence of AEE788 (5 μ M for MCF-7 A2 and 0.5 μ M for BT474 A3). Luciferase activity was normalised by β-galactosidase from cotransfected pCH110. Normalised luciferase activity from quadruplicate wells was expressed relative to that of the vehicle-treated control. Bars represent ±s.e.m. *P<0.05, **P<0.01, are derived from the comparison of the endocrine agent alone vs the combination with AEE788 by Student's unpaired t-test. Effects were confirmed in two independent experiments. (C) Cells were treated with a standard concentration of androstenedione (10 nM) alone or in combination with 10 nM 4-OH tamoxifen or 10 nM letrozole±0.5 μ M AEE788. Quantitative reverse transcriptase PCR was used to measure the expression of TFF1, (D) progesterone receptor (PGR) and (E). ESR1. Bars represent ±s.e.m.
