Transforming growth factor β suppresses β-catenin/Wnt signaling and stimulates an adhesion response in human colon carcinoma cells in a Smad4/DPC4 independent manner

Transforming growth factor β (TGFβ) suppresses the malignant phenotype of human colon carcinoma cells through diverse cellular pathways. Activation of β-catenin/Wnt signal pathway underlies the malignant phenotype of human colon carcinomas. The Smad family of signal transducing, sequence-specific transcription activators are mediators of TGFβ signaling. In this report, we showed that TGFβ suppressed the β-catenin/Wnt signal pathway in human colon carcinoma cells and stimulated an adhesion response in these cells in a Smad4/DPC4 independent manner. Smad/DCP4, however, was found to be linked to the growth-inhibitory action of TGFβ.