Abstract
Aberrant activation of beta-catenin signaling has been implicated in the development of human cancers. As a Wnt signal transducer, beta-catenin forms a complex with the lymphocyte enhancer-binding factor/T cell factor transcription factor and activates downstream targets that promote cell proliferation. Here we developed a Wnt-dependent beta-catenin-mediated heterologous transactivation system, which consisted of a chimeric transcription factor constructed by fusing the GAL4 DNA-binding domain with the full-length beta-catenin, and a GAL4-responsive reporter expressing GFP. The chimeric transcription factor was highly unstable and exerted no detectable transactivating effect on the GAL4-responsive reporter. However, lithium and Wnt1 significantly stabilized this chimeric transactivator, indicating that this transactivation system is regulated by beta-catenin in a Wnt-responsive fashion. Thus, this transactivation system could be used as a functional reporter to identify potential upstream factors that deregulate beta-catenin signaling during tumorigenesis, as well as to screen for potential anti-cancer agents that specifically inhibit beta-catenin signaling in human tumors.
Publication types
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Research Support, Non-U.S. Gov't
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Technical Report
MeSH terms
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Adenocarcinoma / pathology
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Adenoviridae / genetics
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Animals
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Bone Neoplasms
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Cell Line
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Chondrosarcoma / pathology
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Colonic Neoplasms / pathology
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Culture Media, Conditioned / pharmacology
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Cytoskeletal Proteins / antagonists & inhibitors
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Cytoskeletal Proteins / physiology*
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DNA-Binding Proteins
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Fluorometry / methods*
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Genes, Reporter
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Genetic Vectors / genetics
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Green Fluorescent Proteins
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Humans
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Kidney
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Luciferases / analysis
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Luciferases / biosynthesis
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Luciferases / genetics
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Luminescent Proteins / analysis*
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Luminescent Proteins / biosynthesis
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Luminescent Proteins / genetics
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Mice
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Neoplasm Proteins / antagonists & inhibitors
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Neoplasm Proteins / physiology
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Osteosarcoma / pathology
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Protein Structure, Tertiary
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Proto-Oncogene Proteins / physiology*
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Recombinant Fusion Proteins / physiology
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Saccharomyces cerevisiae Proteins / genetics
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Signal Transduction*
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Trans-Activators / antagonists & inhibitors
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Trans-Activators / physiology*
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Transcription Factors / genetics
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Transcriptional Activation*
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Transfection
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Tumor Cells, Cultured
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Wnt Proteins
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Wnt1 Protein
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Zebrafish Proteins*
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beta Catenin
Substances
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CTNNB1 protein, human
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CTNNB1 protein, mouse
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Culture Media, Conditioned
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Cytoskeletal Proteins
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DNA-Binding Proteins
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GAL4 protein, S cerevisiae
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Luminescent Proteins
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Neoplasm Proteins
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Proto-Oncogene Proteins
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Recombinant Fusion Proteins
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Saccharomyces cerevisiae Proteins
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Trans-Activators
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Transcription Factors
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WNT1 protein, human
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Wnt Proteins
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Wnt1 Protein
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Wnt1 protein, mouse
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Zebrafish Proteins
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beta Catenin
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Green Fluorescent Proteins
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Luciferases