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Journal ArticleDOI

Fibroblast growth factors, their receptors and signaling.

01 Sep 2000-Endocrine-related Cancer (Bioscientifica Ltd)-Vol. 7, Iss: 3, pp 165-197
TL;DR: FGF signaling also appears to play a role in tumor growth and angiogenesis, and autocrine FGF signaling may be particularly important in the progression of steroid hormone-dependent cancers to a hormone-independent state.
Abstract: Fibroblast growth factors (FGFs) are small polypeptide growth factors, all of whom share in common certain structural characteristics, and most of whom bind heparin avidly. Many FGFs contain signal peptides for secretion and are secreted into the extracellular environment, where theycan bind to the heparan-like glycosaminoglycans (HLGAGs) of the extracellular matrix (ECM). From this reservoir, FGFs mayact directlyon target cells, or theycan be released through digestion of the ECM or the activityof a carrier protein, a secreted FGF binding protein. FGFs bind specific receptor tyrosine kinases in the context of HLGAGs and this binding induces receptor dimerization and activation, ultimatelyresulting in the activation of various signal transduction cascades. Some FGFs are potent angiogenic factors and most playimportant roles in embry onic development and wound healing. FGF signaling also appears to playa role in tumor growth and angiogenesis, and autocrine FGF signaling maybe particularlyimportant in the progression of steroid hormone-dependent cancers to a hormone-independent state.

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Citations
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Journal ArticleDOI
TL;DR: A model were the intranuclear structures are formed by invagination of ER-derived membrane stacks into the nucleus is suggested, suggesting that they function as deposits of the overexpressed mutant and associated membrane.
Abstract: The expression of several deletion mutants of fibroblast growth factor receptor 4 (FGFR4) was studied in COS-1 cells. FGFR4-mutants lacking most of the extracellular region did not efficiently reach the plasma membrane but accumulated in the endoplasmic reticulum (ER) and Golgi body. A mutant FGFR4 lacking the kinase domain as well as most of the extracellular region (ΔExt/R4Tth) had a distinct intracellular distribution. It localized in part to the nucleus, where it exhibited a striking spotted pattern. Ultrastructural studies showed that the nuclear spots consisted of several layers of membrane that were folded into onion-like structures at the nucleoplasmic side of the nuclear envelope. These intranuclear structures did not contain nuclear pores but were positive for the ER proteins calreticulin and protein disulfide isomerase, in addition to abundant ΔExt/R4Tth. Formation of the intranuclear structures was sensitive to inhibition of protein kinase C. Live microscopy of a green-fluorescent-protein/ΔExt/R4Tth fusion protein showed that the intranuclear structures were stable and immobile, suggesting that they function as deposits of the overexpressed mutant and associated membrane. The ΔExt/R4Tth protein also induced formation of densely packed membrane stacks in the cytosol and we suggest a model were the intranuclear structures are formed by invagination of ER-derived membrane stacks into the nucleus.

15 citations


Cites background from "Fibroblast growth factors, their re..."

  • ...…intracellular region affecting kinase activity or the availability of docking sites for downstream effectors (Ueno et al., 1992; Yan et al., 1993; Wang and Thomas, 1994; Kishi et al., 1994; van Heumen et al., 1999; Powers et al., 2000; Ezzat et al., 2001; Terada et al., 2001; Burgar et al., 2002)....

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Journal ArticleDOI
TL;DR: The results of the present study demonstrate that single extracellular point mutations in the FGFR2 have a profound effect on intracellular signalling and ultimately on cell fate.
Abstract: Two independent gain-of-function point mutations (S252W and P253R) in the extracellular region of the FGFR2 (fibroblast growth factor receptor 2) increase the binding affinity for the growth factor. The effect of this enhanced growth factor binding by these mutants is expected to be an increase in activation of regular signalling pathways from FGFR2 as a result of more receptors being engaged by ligand at any given time. Using PC12 (pheochromocytoma) cells as a model cell system we investigated the effect of these mutations on protein phosphorylation including the receptor, the activation of downstream signalling pathways and cell differentiation. Our results show that the effects of both of these extracellular mutations have unexpected intracellular phenotypes and cellular responses. Receptor phosphorylation was altered in both the ligand-stimulated and unstimulated states. The mutants also resulted in differential phosphorylation of a number of intracellular proteins. Both mutations resulted in enhanced ERK1/2 (extracellular-signalregulated kinase1/2) activation. Although ERK1/2 activation is believed to transduce signals resulting in cell differentiation, this response was abrogated in the cells expressing the mutant receptors. The results of the present study demonstrate that single extracellular point mutations in the FGFR2 have a profound effect on intracellular signalling and ultimately on cell fate.

15 citations

Journal ArticleDOI
TL;DR: It is concluded that TSH stimulates FGFR1 but not FGF-2 expression, and TSH synergizes with PKC activators, which may contribute to goitrogenesis.
Abstract: Thyroidal levels of fibroblast growth factor-2 (FGF-2) and fibroblast growth factor receptor 1 (FGFR1) are elevated in human thyroid hyperplasia. To understand the significance of this, effects of ...

15 citations


Cites background from "Fibroblast growth factors, their re..."

  • ...Similarly, the other FGF receptors and receptor isoforms, in particular FGFR2, which has been shown to be expressed in human thyroid cells (20), and FGF-binding proteins (33) are of unknown importance....

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  • ...There are four high-affinity membrane FGF receptors identified in humans, FGFR1–FGFR4, which have a common structure of extracellular immunoglobulinlike loops, a transmembrane domain, and an intracellular tyrosine kinase domain (33)....

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  • ...FIBROBLAST GROWTH FACTORS (FGFs) are a large family of heparin-binding growth factors, now comprising 23 members, which have been detected in almost all tissues and shown to be mitogenic to many cell types (16, 33)....

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Journal ArticleDOI
TL;DR: The data indicated that tbFGF-LPs-PTX significantly increased the accumulation in tumor and prolonged the retention time, suggesting that it was a promise tumor-targeted delivery system and might provide a new treatment strategy for tumors.

15 citations

References
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Journal ArticleDOI
22 Feb 1991-Cell
TL;DR: It is demonstrated that free heparin and heparan sulfate can reconstitute a low affinity receptor that is, in turn, required for the high affinity binding of bFGF.

2,448 citations

Journal ArticleDOI
16 Feb 1995-Nature
TL;DR: This work highlights conserved protein domains that act as key regulatory participants in many of these different signalling pathways in multicellular organisms.
Abstract: Communication between cells assumes particular importance in multicellular organisms. The growth, migration and differentiation of cells in the embryo, and their organization into specific tissues, depend on signals transmitted from one cell to another. In the adult, cell signalling orchestrates normal cellular behaviour and responses to wounding and infection. The consequences of breakdowns in this signalling underlie cancer, diabetes and disorders of the immune and cardiovascular systems. Conserved protein domains that act as key regulatory participants in many of these different signalling pathways are highlighted.

2,433 citations


"Fibroblast growth factors, their re..." refers background in this paper

  • ...One way these recruited target proteins may be localized to the activated receptor is through the interaction between their Src-homology 2 (SH2) domains and specific phosphotyrosine residues on the activated receptor (Pawson 1995)....

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  • ...Phosphorylated tyrosine residues, in turn, recruit other signaling molecules to the activated receptors and propagate the signal through many possible transduction pathways (Pawson 1995)....

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Journal ArticleDOI
TL;DR: Electron microscopic examination of the corneal neovascularization of thalidomide-treated rabbits revealed specific ultrastructural changes similar to those seen in the deformed limb bud vasculature of Thalidomid-treated embryos.
Abstract: Thalidomide is a potent teratogen causing dysmelia (stunted limb growth) in humans. We have demonstrated that orally administered thalidomide is an inhibitor of angiogenesis induced by basic fibroblast growth factor in a rabbit cornea micropocket assay. Experiments including the analysis of thalidomide analogs revealed that the antiangiogenic activity correlated with the teratogenicity but not with the sedative or the mild immunosuppressive properties of thalidomide. Electron microscopic examination of the corneal neovascularization of thalidomide-treated rabbits revealed specific ultrastructural changes similar to those seen in the deformed limb bud vasculature of thalidomide-treated embryos. These experiments shed light on the mechanism of thalidomide's teratogenicity and hold promise for the potential use of thalidomide as an orally administered drug for the treatment of many diverse diseases dependent on angiogenesis.

2,364 citations

Journal ArticleDOI
TL;DR: It is demonstrated that FGF 1 is the only FGF that can activate all FGF receptor splice variants and the relative activity of all the other members of the FGF family is determined.

2,066 citations


"Fibroblast growth factors, their re..." refers background in this paper

  • ...†From Ornitz et al. (1996), except where stated; ‡From Koga et al. (1995); §From Miralles et al. (1999); ¶From Xu et al. (1999). topologically identical to interleukin-1β (IL-1β) (Zhu et al. 1991), with which some members also share the feature of secretion by an endoplasmic reticulum…...

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  • ...Mutation of all four cysteines to serines results in a protein with the same secondary structure and equally mitogenic for 3T3 cells as the wild-type FGF-2 (Foxet al. 1988), suggesting that the formation of disulfide bridges is not important for the secondary structure and mitogenic activity of…...

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  • ...Ornitz et al. (1996) determined the specificity of different FGFs for different receptor isoforms by overexpressing these isoforms in Baf3 cells, which do not normally express FGFRs, and assaying for [3H]thymidine incorporation in these cells following treatment with different FGFs (see Table 2)....

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  • ...1, IIIb 100 60 34 16 4 5 6 4 4 1, IIIc 100 104 0 102 59 55 0 1 21 2, IIIb 100 9 45 15 5 5 81 4 7 2, IIIc 100 64 4 94 25 61 2.5 16 89 3, IIIb 100 1 2 1 1 1 1 1 42 3, IIIc 100 107 1 69 12 9 1 41 96 4 100 113 6 108 7 79 2 76 75 Modified from Ornitz et al. (1996)....

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Journal ArticleDOI

1,994 citations


"Fibroblast growth factors, their re..." refers background in this paper

  • ...Defining features of the FGF family are a strong affinity for heparin and HLGAGs (Burgess & Maciag 1989), as well as a central core of 140 amino acids that is highly homologous between different family members....

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