Abstract
Human epidermal growth factor receptor 2 (HER2) overexpression stimulates cell growth in p53-mutated cells while it inhibits cell proliferation in those with wild-type p53, but the molecular mechanism is unknown. The Dmp1 promoter was activated by HER2/neu through the phosphatidylinositol-3'-kinase-Akt-NF-κB pathway, which in turn stimulated Arf transcription. Binding of p65 and p52 subunits of NF-κB was shown to the Dmp1 promoter and that of Dmp1 to the Arf promoter on HER2/neu overexpression. Both Dmp1 and p53 were induced in premalignant lesions from mouse mammary tumor virus-neu mice, and mammary tumorigenesis was significantly accelerated in both Dmp1+/- and Dmp1-/- mice. Selective deletion of Dmp1 and/or overexpression of Tbx2/Pokemon was found in >50% of wild-type HER2/neu carcinomas, although the involvement of Arf, Mdm2, or p53 was rare. Tumors from Dmp1+/-, Dmp1-/-, and wild-type neu mice with hemizygous Dmp1 deletion showed significant downregulation of Arf and p21Cip1/WAF1, showing p53 inactivity and more aggressive phenotypes than tumors without Dmp1 deletion. Notably, endogenous hDMP1 mRNA decreased when HER2 was depleted in human breast cancer cells. Our study shows the pivotal roles of Dmp1 in HER2/neu-p53 signaling and breast carcinogenesis.
Copyright © 2010 AACR.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Base Sequence
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Blotting, Western
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Breast Neoplasms / genetics
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Breast Neoplasms / metabolism
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Breast Neoplasms / pathology
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Cell Line, Tumor
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Cells, Cultured
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Cyclin-Dependent Kinase Inhibitor p16 / genetics
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Cyclin-Dependent Kinase Inhibitor p16 / metabolism*
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Cyclin-Dependent Kinase Inhibitor p21 / genetics
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Cyclin-Dependent Kinase Inhibitor p21 / metabolism
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Epithelial Cells / metabolism
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Extracellular Matrix Proteins / genetics
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Extracellular Matrix Proteins / metabolism*
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Female
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Gene Expression
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Humans
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Male
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Mammary Neoplasms, Experimental / genetics
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Mammary Neoplasms, Experimental / metabolism
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Mammary Neoplasms, Experimental / pathology
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Mice
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Mice, Inbred Strains
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Mice, Knockout
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Molecular Sequence Data
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Phosphoproteins / genetics
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Phosphoproteins / metabolism*
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Promoter Regions, Genetic / genetics
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Protein Binding
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Receptor, ErbB-2 / genetics
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Receptor, ErbB-2 / metabolism*
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Reverse Transcriptase Polymerase Chain Reaction
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Signal Transduction*
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Tumor Suppressor Protein p53 / genetics
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Tumor Suppressor Protein p53 / metabolism*
Substances
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Cyclin-Dependent Kinase Inhibitor p16
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Cyclin-Dependent Kinase Inhibitor p21
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DMP1 protein, human
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Extracellular Matrix Proteins
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Phosphoproteins
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Tumor Suppressor Protein p53
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Receptor, ErbB-2