Abstract
Fibroblast growth factor receptor 1 (FGFR1) is frequently amplified and highly expressed in lobular carcinomas of the breast. In this report, we evaluated the biological activity of FGFR1 in a wide range of in vitro assays. Conditional activation of FGFR1 in the nontransformed MCF10A human mammary cell line, MCF10A, resulted in cellular transformation marked by epidermal growth factor-independent cell growth, anchorage-independent cell proliferation and survival, loss of cell polarity, and epithelial-to-mesenchymal transition. Interestingly, small-molecule or small interfering RNA inhibition of ribosomal S6 kinase (RSK) activity induced death of the FGFR1-transformed cells, but not of the parental MCF10A cell line. The dependence of FGFR1-transformed cells on RSK activity was further confirmed in cell lines derived from mouse and human lobular carcinomas that possess high FGFR1 activity. Taken together, these results show the transforming activity of FGFR1 in mammary epithelial cells and identify RSK as a critical component of FGFR1 signaling in lobular carcinomas, thus implicating RSK as a candidate therapeutic target in FGFR1-expressing tumors.
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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Breast Neoplasms / genetics
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Breast Neoplasms / metabolism*
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Breast Neoplasms / pathology
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Carcinoma, Lobular / enzymology
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Carcinoma, Lobular / genetics
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Carcinoma, Lobular / metabolism
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Carcinoma, Lobular / pathology
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Cell Growth Processes / physiology
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Cell Line, Tumor
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Cell Survival / physiology
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Cell Transformation, Neoplastic / genetics
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Cell Transformation, Neoplastic / metabolism*
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Cell Transformation, Neoplastic / pathology
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Epithelial Cells / metabolism
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Epithelial Cells / pathology
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Humans
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Mammary Glands, Human / enzymology
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Mammary Glands, Human / metabolism*
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Mammary Glands, Human / pathology
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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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Receptor, Fibroblast Growth Factor, Type 1 / biosynthesis
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Receptor, Fibroblast Growth Factor, Type 1 / genetics
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Receptor, Fibroblast Growth Factor, Type 1 / metabolism*
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Ribosomal Protein S6 Kinases, 90-kDa / antagonists & inhibitors
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Ribosomal Protein S6 Kinases, 90-kDa / metabolism*
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Signal Transduction
Substances
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Receptor, Fibroblast Growth Factor, Type 1
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Ribosomal Protein S6 Kinases, 90-kDa