Targeting angiogenesis driven by fibroblast growth factor using RPT835, an FGFR2 inhibitor.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e22097-e22097
Author(s):  
Evgenia Stepanova ◽  
Eliso Solomko ◽  
Oxana Ryabaya ◽  
Nina Peretolchina ◽  
Ilya Tsimafeyeu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Umbilical Vein ◽  
Endothelial Cell Proliferation ◽  
Control Group ◽  
Fibroblast Growth ◽  
Basic Fgf ◽  
Signaling Axis

e22097 Background: The fibroblast growth factor (FGF)/FGF receptors (FGFR) signaling axis plays a key role in driving tumor angiogenesis. There is little data on the targeting of FGF-induced angiogenesis. We describe here the targeting angiogenesis driven by FGF using RPT835, novel inhibitor of the FGFR2 extracellular domain (received from RusPharmTech, LLC). Methods: To assess the efficacy of RPT835 on FGF-mediated endothelial cells proliferation, the human umbilical vein endothelial FGFR-expressing cells (HUVEC) were incubated in a 96-well microculture plate and were treated with serially diluted RPT835 or Brivanib as a control. Basic FGF was added at a concentration of 25 ng/ml. Control wells were left untreated. Cell growth inhibition was determined using Promega’s Cell Titer-Glo assay. In vivo angiogenesis was measured with subcutaneously implanted Matrigel plugs containing bFGF (100 ng/ml) or bFGF (100 ng/ml) + bevacizumab (10 mg/kg) or bFGF (100 ng/ml) + RPT835 (15 mg/kg). Control group was without stimulation and treatment. Each group included 3 mice. Number of endothelial cells/vessels was calculated. Results: Basic FGF significantly increased proliferation of the HUVEC cells (P=0.001) in untreated control group. RPT835 significantly inhibited FGF-triggered endothelial cell proliferation when compared with control (P<0.001) or brivanib (P<0.001, IC50=289 nmol/L) with IC50 of 11 nmol/L. In vivo, bFGF induced proliferation of endotheliocytes and mature vessels formation (P<0.001). There were no vessels in FGFR2 inhibitor group. Bevacizumab did not decrease number of vessels in comparison with FGF-stimulated angiogenesis (P=0.9). Conclusions: Inhibition of bFGF/FGFR2 pathway resulted in effects on endothelial cells proliferation andmature vessels formation. Bevacizumab had no activity in FGF-induced angiogenesis.

Heparins Inhibit Tumor Angiogenesis by Sequestering Fibroblast Growth Factor (FGF) from Tumor Vascular Endothelial Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2662-2662
Author(s):  
Shannon L. Smiley ◽  
Dale O. Henry ◽  
Shang-Chiung Chen ◽  
Michael K.K. Wong
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tumor Angiogenesis ◽  
Experimental Models ◽  
Control Group ◽  
Molecular Evidence ◽  
Dependent Manner ◽  
Fibroblast Growth

Abstract The association between cancer and thromboembolic disease is a well-known phenomenon and contributes to the morbidity and mortality of cancer patients. Clinical studies of thrombosis in these patients show that heparins may have beneficial effects on survival. Antithrombotic agents have been shown to exert an anti-tumor effect in various experimental models however the underlying mechanism remains unknown. We show that heparins inhibit in vivo tumor angiogenesis and offer molecular evidence that heparins exert an anti-angiogenic effect by directly sequestering fibroblast growth factor (FGF) from its receptor on tumor derived endothelial cells (TDECs). NIH-3T3 fibroblasts were stably transfected with an expression construct that results in the constitutive excretion of FGF-1 (Clone C). Clone C gives rise to aggressive and highly angiogenic xenograft tumors. Clone C was inoculated into nude mice and therapeutic doses of Low Molecular Weight (LMW) heparins were injected daily beginning on Day 2. Tumors in the control group were grossly angiogenic and highly vascularized. In contrast, the heparin treated tumors were pale and possessed only scant peri-tumoral vessels. In order to assess the biologic mechanism of this, murine TDECs were isolated and cultured as previously published. Unfractionated and LMW heparins inhibit FGF-induced TDEC mitogenesis in a concentration- and time-dependent manner. FGF overcame and rescued heparin-induced inhibition suggesting that an FGF-heparin interaction is responsible. In order to test the hypothesis that heparin strips and sequesters FGF off its receptor on TDECs, we used a FGF protein fused to a hemagglutinin peptide tag at the carboxyl-terminus end (FGF-HA). FGF-HA is biologically identical to wild type FGF, but its detection limit is 10X more sensitive. FGF-HA was allowed to bind to FGFR on TDECs. These cells were subsequently incubated with Heparin covalently linked to Sepharose beads (Heparin-Sepharose) or to Sepharose alone. These beads were removed, and TDEC growth analyzed prospectively. Heparin-Sepharose treatment results in significant TDEC growth inhibition as compared to incubation with Sepharose alone. Western blot analysis shows that FGF was sequestered only on the Heparin-Sepharose beads. Conclusion: The anti-angiogenic mechanism of heparins resides, in part, in its ability to sequester angiogenic cytokines such as FGF from its receptor on tumor endothelium.

Electron Microscopic Immunolocalization of Basic Fibroblast Growth Factor-Like Molecules in Capillary Endothelial Cells

1998 ◽  
Vol 4 (S2) ◽  
pp. 1100-1101
Author(s):  
Ranan Gullhan Aktas ◽  
Robert J. Kayton
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Basic Fibroblast Growth Factor ◽  
Immunogold Labeling ◽  
Fibroblast Growth ◽  
Electron Microscopic ◽  
Adult Rats

Basic fibroblast growth factor (bFGF) is a potent angiogenic polypeptide. It promotes angiogenesis in vivo and in vitro by stimulating migration, proliferation and proteolytic activity of endothelial cells. Whereas several effects of exogenous bFGF on endothelial cells have been described, it has remained unclear how endogenous bFGF produced by vascular endothelial cells regulate angiogenesis.To further investigate functional implications of the distribution of bFGF, we undertook the present study. Our aims were (i) to identify the specific location of bFGF in endothelial cells using electron microscopy immunogold labeling technique (ii) to determine the distribution of bFGF in capillaries of different types of tissues.Tissue samples from sciatic nerve, hippocampus, adrenal gland and kidney of normal adult rats were fixed in 4% paraformaldehyde/1 to 5% glutaraldehyde and embedded in Spurr's resin. Ultrathin sections were labeled with either polyclonal (F3393-Sigma) or monoclonal antibodies (F6162-Sigma, C3316-ZymoGenetics) specific for bFGF using a two-step immunogold labeling method.

Capillary endothelial cells secrete a heparin-binding mitogen for pericytes

1992 ◽  
Vol 103 (2) ◽  
pp. 453-461
Author(s):  
J.C. Swinscoe ◽  
E.C. Carlson
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth ◽  
Heparin Binding ◽  
Acidic Fibroblast Growth Factor ◽  
Phenotypic Characteristics ◽  
Retinal Microvasculature ◽  
Capillary Endothelial Cells

The cells of the retinal microvasculature consist predominantly of mesodermally derived pericytes and endothelial cells, and the regulatory factors which govern their co-ordinated growth and define their phenotypic characteristics in vivo may be regarded as key elements of the angiogenic process. An investigation of these cells in co-culture experiments has led to the identification of a potent mitogen for pericytes in medium conditioned by retinal endothelial cells (EC-FBS). EC-FBS activity was shown to be non-dialyzable, and stable to both heat and acid treatment. EC-FBS was inactivated by passage over a heparin-Agarose column. The column-bound activity could be eluted as a single peak at approximately 1.0 M NaCl. Stimulation of pericyte growth was also achieved with platelet-derived growth factor (PDGF), acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) and could be blocked by using the appropriate antiserum (anti-PDGF or anti-aFGF). Neither antisera, however, blocked the activity of EC-FBS. The EC-FBS mitogen markedly altered the phenotypic behavior of pericytes compared with PDGF and the FGFs; yet, unlike them, it failed to stimulate the growth of smooth muscle cells (SMC) and Balb/c 3T3 cells.

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