Fig. 3. E-cadherin controls the transcriptional activity of β-catenin on the fibronectin promoter. (A) Snail1 and E-cadherin modulate β-catenin and TCF4 transcriptional activity. The activity of a β-catenin–TCF4-dependent promoter (TOP) was determined in SW-480 cells stably transfected with Snail1-HA, E-cadherin or both. The results are the average ± s.d. of three experiments. (B) Binding of β-catenin to the fibronectin promoter is sensitive to E-cadherin. ChIP assays were carried out as described in the Materials and Methods, immunoprecipitating crosslinked nuclear extracts from SW-480 cells stably transfected with the indicated genes. The average ± s.d. of two experiments is shown.