Project description:We evaluated the role of TTF-1/NKX2-1 on Smad3 and Smad4 binding in lung cancer cell lines. Smad3 binding sites in A549 cells and Smad3, Smad4, and TTF-1/NKX2-1 binding sites in H441 cells were determined by ChIP-seq.
Project description:Transforming growth factor-beta (TGF-beta) transmits signals that facilitate cancer progression. Especially, epithelial-mesenchymal transition (EMT) induced by TGF-beta is considered to crucially contribute to the malignant phenotype of cancer cells. Here we report that the EMT-associated cellular responses induced by TGF-beta are mediated through distinct signaling pathways that diverge at Smad3; cell motility and epithelial marker downregulation are Smad3-dependent while mesenchymal marker induction is not. Furthermore, using a chimeric protein approach in SMAD3 knockout A549 cells, we found that the beta 4 region in the MH1 domain of Smad3 is indispensable for TGF-beta–induced cell motility, but not for epithelial marker downregulation. A transcriptome analysis was performed using A549 cells expressing Smad3 mutant of the MH1 domain.
