Abstract
To investigate the functions of the p53 tumor suppressor, we created a new knock-in gene replacement mouse model in which the endogenous Trp53 gene is substituted by one encoding p53ER(TAM), a p53 fusion protein whose function is completely dependent on ectopic provision of 4-hydroxytamoxifen. We show here that both tissues in vivo and cells in vitro derived from such mice can be rapidly toggled between wild-type and p53 knockout states. Using this rapid perturbation model, we define the kinetics, dependence, persistence and reversibility of p53-mediated responses to DNA damage in tissues in vivo and to activation of the Ras oncoprotein and stress in vitro. This is the first example to our knowledge of a new class of genetic model that allows the specific, rapid and reversible perturbation of the function of a single endogenous gene in vivo.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Apoptosis / drug effects
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Apoptosis / radiation effects
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Cells, Cultured
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DNA Damage / drug effects
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Embryo, Mammalian / cytology
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Fibroblasts / metabolism
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Gamma Rays
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Gene Expression Regulation, Neoplastic
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Genes, p53
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Genes, ras / genetics
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Intestine, Small / drug effects
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Intestine, Small / pathology
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Intestine, Small / radiation effects
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Mice
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Mice, Transgenic
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Models, Animal
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Neoplasms / genetics*
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Neoplasms / metabolism
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Neoplasms / pathology
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Spleen / drug effects
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Spleen / pathology
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Spleen / radiation effects
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Tamoxifen / analogs & derivatives*
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Tamoxifen / pharmacology
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Thymus Gland / drug effects
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Thymus Gland / pathology
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Thymus Gland / radiation effects
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Time Factors
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Tumor Suppressor Protein p53 / genetics
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Tumor Suppressor Protein p53 / physiology*
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Whole-Body Irradiation
Substances
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Tumor Suppressor Protein p53
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Tamoxifen
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afimoxifene