Figure 4
PV mimics the effects of E2-ERα on responses from BT-549 cells. (A & B) Synthesis of functional receptor proteins. BT-549 cells were infected with an adenovirus bearing none (Ad5) or a cDNA for ERα, ERαEBD, PV, ERαEBD at 80, 20, 20, 60 and 80 MOIs, respectively. The total MOI was adjusted to 80 MOI by supplementing with Ad5. (A) Extracts of infected BT-549 (25 µg) cells at 48 h after infection were subjected to WB using the horseradish peroxidase-conjugated monoclonal Flag antibody. Molecular mass in kDa is indicated. (B) Cell extracts were also subjected to EMSA in the presence (+) or absence (−) of a Flag antibody. ERE indicates the unbound and R-ERE depicts the receptor-bound radiolabeled ERE. F denotes the radiolabeled ERE only. (C, D) Infected cells in the presence (E2) or absence (−) of 10−9 M E2 for 6 d were subjected to (C) cell counting for cellular proliferation or (D) Annexin V assay at 96 h after infection for cellular death. The mean ± SEM, which represents three independent experiments, indicate percentage (%) change in cell number compared with those observed in cells infected with Ad5 in the absence of E2, which is set to 100. Asterisk (*) indicates significant change.