Fig. 2.

Effects of ERα on AhR-mediated transcription. HepG2 cells were transiently transfected with pGL3-XRE and co-transfected or not with human ERα expression plasmid as described in Section 2. Cells were treated with TCDD and/or E2 over a period of 20 h. An induction equal to 100% was attributed to the luciferase activity of treatment with TCDD in ERα-transfected cells and all results were expressed as a percentage of the luciferase activity of this positive control (corresponding to 1,740,574 ± 484,008 cps). Mean ± SD (n ≥ 3); One-way ANOVA followed by Tukey's post test: significantly different from solvent control (DMSO 0.2% max.): *p ≤ 0.01, **p ≤ 0.001, ***p ≤ 0.0001; significant difference between respective TCDD and E2/TCDD treatments as indicated; n.s.: not significant.