title: Interaction between Smad7 and beta-catenin: importance for transforming growth factor beta-induced apoptosis.
abstract: Members of the transforming growth factor beta (TGF-beta) and Wnt/wingless superfamilies regulate cell fate during development and tissue maintenance. Here we report that Smad7 interacts with beta-catenin and lymphoid enhancer binding factor 1/T-cell-specific factor (LEF1/TCF), transcriptional regulators in Wnt signaling, in a TGF-beta-dependent manner. Smad7 was found to be required for TGF-beta1-induced accumulation of beta-catenin and LEF1 in human prostate cancer (PC-3U) cells as well as in human keratinocytes (HaCaT cells). Moreover, when the endogenous Smad7 was repressed by specific small interfering RNA, TGF-beta-induced increase of activated p38, Akt phosphorylated on Ser473, glycogen synthase kinase 3beta phosphorylated on Ser9 was prevented, as well as the TGF-beta-induced association between beta-catenin and LEF1. Notably, the observed physical association of Smad7 and beta-catenin was found to be important for TGF-beta-induced apoptosis, since suppression of beta-catenin expression by small interfering RNA decreased the apoptotic response to TGF-beta.
authors.affiliation: Ludwig Institute for Cancer Research, Box 595, Biomedical Center, SE 751 24 Uppsala, Sweden.
authors.forename: Sofia
authors.initials: S
authors.lastname: Edlund
authors.forename: So Young
authors.initials: SY
authors.lastname: Lee
authors.forename: Susanne
authors.initials: S
authors.lastname: Grimsby
authors.forename: Shouthing
authors.initials: S
authors.lastname: Zhang
authors.forename: Pontus
authors.initials: P
authors.lastname: Aspenström
authors.forename: Carl-Henrik
authors.initials: CH
authors.lastname: Heldin
authors.forename: Maréne
authors.initials: M
authors.lastname: Landström
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D019556:COS Cells; D002458:Cell Fractionation; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006801:Humans; D051821:Lymphoid Enhancer-Binding Factor 1; D008297:Male; D051379:Mice; D010766:Phosphorylation / Q000187:drug effects; D011471:Prostatic Neoplasms / Q000378:metabolism; D011485:Protein Binding / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D034741:RNA, Small Interfering / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D051906:Smad7 Protein; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D014407:Tumor Cells, Cultured; D051176:beta Catenin; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: C495270:CTNNB1 protein, human; C495267:CTNNB1 protein, mouse; D003598:Cytoskeletal Proteins; D004268:DNA-Binding Proteins; C497573:LEF1 protein, human; C497574:Lef1 protein, mouse; D051821:Lymphoid Enhancer-Binding Factor 1; D011518:Proto-Oncogene Proteins; D034741:RNA, Small Interfering; C497806:SMAD7 protein, human; D051906:Smad7 Protein; C497807:Smad7 protein, mouse; D015534:Trans-Activators; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D051176:beta Catenin; D012694:Serine; C494918:AKT1 protein, human; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D048051:p38 Mitogen-Activated Protein Kinases; D038362:Glycogen Synthase Kinase 3