scholarly journals Cell transformation by fibroblast growth factors can be suppressed by truncated fibroblast growth factor receptors.

1994 ◽  
Vol 14 (11) ◽  
pp. 7660-7669 ◽  
Author(s):  
Y Li ◽  
C Basilico ◽  
A Mansukhani
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tyrosine Kinases ◽  
Dominant Negative ◽  
Receptor Expression ◽  
Scatchard Analysis ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors ◽  
Truncated Receptor ◽  
Nih 3T3

Ligand-induced dimerization and transphosphorylation are thought to be important events by which receptor tyrosine kinases generate cellular signals. We have investigated the ability of signalling-defective, truncated fibroblast growth factor (FGF) receptors (FGFR-1 and FGFR-2) to block the FGF response in cells that express both types of endogenous FGF receptors. When these dominant negative receptors are expressed in NIH 3T3 cells transformed by the secreted FGF-4, the transformed properties of the cells can be reverted to various degrees, with better reversion phenotype correlating with higher levels of truncated receptor expression. Furthermore, truncated FGFR-2 is significantly more efficient at producing reversion than FGFR-1, indicating that FGF-4 preferentially utilizes the FGFR-2 signalling pathway. NIH 3T3 clones expressing these truncated receptors are more resistant to FGF-induced mitogenesis and also exhibit reduced tyrosine phosphorylation upon treatment with FGF. The block in FGF-signalling, however, can be overcome by the addition of excess growth factor. The truncated receptors have binding affinities that are four- to eightfold lower than those of wild-type receptors, as measured by Scatchard analysis. We also observed a partial specificity in the responses of truncated-receptor-expressing clones to FGF-2 or FGF-4. Our results suggest that the block to signal transduction produced by kinase-negative FGF receptors is achieved through a combination of dominant negative effects and competition for growth factor binding with functional receptors.

Cell transformation by fibroblast growth factors can be suppressed by truncated fibroblast growth factor receptors

1994 ◽  
Vol 14 (11) ◽  
pp. 7660-7669
Author(s):  
Y Li ◽  
C Basilico ◽  
A Mansukhani
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tyrosine Kinases ◽  
Dominant Negative ◽  
Receptor Expression ◽  
Scatchard Analysis ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors ◽  
Truncated Receptor ◽  
Nih 3T3

Ligand-induced dimerization and transphosphorylation are thought to be important events by which receptor tyrosine kinases generate cellular signals. We have investigated the ability of signalling-defective, truncated fibroblast growth factor (FGF) receptors (FGFR-1 and FGFR-2) to block the FGF response in cells that express both types of endogenous FGF receptors. When these dominant negative receptors are expressed in NIH 3T3 cells transformed by the secreted FGF-4, the transformed properties of the cells can be reverted to various degrees, with better reversion phenotype correlating with higher levels of truncated receptor expression. Furthermore, truncated FGFR-2 is significantly more efficient at producing reversion than FGFR-1, indicating that FGF-4 preferentially utilizes the FGFR-2 signalling pathway. NIH 3T3 clones expressing these truncated receptors are more resistant to FGF-induced mitogenesis and also exhibit reduced tyrosine phosphorylation upon treatment with FGF. The block in FGF-signalling, however, can be overcome by the addition of excess growth factor. The truncated receptors have binding affinities that are four- to eightfold lower than those of wild-type receptors, as measured by Scatchard analysis. We also observed a partial specificity in the responses of truncated-receptor-expressing clones to FGF-2 or FGF-4. Our results suggest that the block to signal transduction produced by kinase-negative FGF receptors is achieved through a combination of dominant negative effects and competition for growth factor binding with functional receptors.

scholarly journals Targeting fibroblast growth factor receptors to combat aggressive ependymoma

2021 ◽  
Author(s):  
Daniela Lötsch ◽  
Dominik Kirchhofer ◽  
Bernhard Englinger ◽  
Li Jiang ◽  
Konstantin Okonechnikov ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Molecular Mechanisms ◽  
Radial Glia ◽  
Growth Factor Receptors ◽  
Dominant Negative ◽  
Mrna Levels ◽  
Fibroblast Growth ◽  
Cell Models ◽  
Fibroblast Growth Factor Receptors

AbstractEpendymomas (EPN) are central nervous system tumors comprising both aggressive and more benign molecular subtypes. However, therapy of the high-risk subtypes posterior fossa group A (PF-A) and supratentorial RELA-fusion positive (ST-RELA) is limited to gross total resection and radiotherapy, as effective systemic treatment concepts are still lacking. We have recently described fibroblast growth factor receptors 1 and 3 (FGFR1/FGFR3) as oncogenic drivers of EPN. However, the underlying molecular mechanisms and their potential as therapeutic targets have not yet been investigated in detail. Making use of transcriptomic data across 467 EPN tissues, we found that FGFR1 and FGFR3 were both widely expressed across all molecular groups. FGFR3 mRNA levels were enriched in ST-RELA showing the highest expression among EPN as well as other brain tumors. We further identified high expression levels of fibroblast growth factor 1 and 2 (FGF1, FGF2) across all EPN subtypes while FGF9 was elevated in ST-EPN. Interrogation of our EPN single-cell RNA-sequencing data revealed that FGFR3 was further enriched in cycling and progenitor-like cell populations. Corroboratively, we found FGFR3 to be predominantly expressed in radial glia cells in both mouse embryonal and human brain datasets. Moreover, we detected alternative splicing of the FGFR1/3-IIIc variant, which is known to enhance ligand affinity and FGFR signaling. Dominant-negative interruption of FGFR1/3 activation in PF-A and ST-RELA cell models demonstrated inhibition of key oncogenic pathways leading to reduced cell growth and stem cell characteristics. To explore the feasibility of therapeutically targeting FGFR, we tested a panel of FGFR inhibitors in 12 patient-derived EPN cell models revealing sensitivity in the low-micromolar to nano-molar range. Finally, we gain the first clinical evidence for the activity of the FGFR inhibitor nintedanib in the treatment of a patient with recurrent ST-RELA. Together, these preclinical and clinical data suggest FGFR inhibition as a novel and feasible approach to combat aggressive EPN.

scholarly journals Self-renewal of human embryonic stem cells requires insulin-like growth factor-1 receptor and ERBB2 receptor signaling

Blood ◽  
2007 ◽  
Vol 110 (12) ◽  
pp. 4111-4119 ◽  
Author(s):  
Linlin Wang ◽  
Thomas C. Schulz ◽  
Eric S. Sherrer ◽  
Derek S. Dauphin ◽  
Soojung Shin ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tyrosine Phosphorylation ◽  
Tyrosine Kinases ◽  
Embryonic Stem ◽  
Growth Factor Receptor ◽  
Insulin Like Growth Factor ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors ◽  
Self Renewal

Abstract Despite progress in developing defined conditions for human embryonic stem cell (hESC) cultures, little is known about the cell-surface receptors that are activated under conditions supportive of hESC self-renewal. A simultaneous interrogation of 42 receptor tyrosine kinases (RTKs) in hESCs following stimulation with mouse embryonic fibroblast (MEF) conditioned medium (CM) revealed rapid and prominent tyrosine phosphorylation of insulin receptor (IR) and insulin-like growth factor-1 receptor (IGF1R); less prominent tyrosine phosphorylation of epidermal growth factor receptor (EGFR) family members, including ERBB2 and ERBB3; and trace phosphorylation of fibroblast growth factor receptors. Intense IGF1R and IR phosphorylation occurred in the absence of MEF conditioning (NCM) and was attributable to high concentrations of insulin in the proprietary KnockOut Serum Replacer (KSR). Inhibition of IGF1R using a blocking antibody or lentivirus-delivered shRNA reduced hESC self-renewal and promoted differentiation, while disruption of ERBB2 signaling with the selective inhibitor AG825 severely inhibited hESC proliferation and promoted apoptosis. A simple defined medium containing an IGF1 analog, heregulin-1β (a ligand for ERBB2/ERBB3), fibroblast growth factor-2 (FGF2), and activin A supported long-term growth of multiple hESC lines. These studies identify previously unappreciated RTKs that support hESC proliferation and self-renewal, and provide a rationally designed medium for the growth and maintenance of pluripotent hESCs.

scholarly journals Fibroblast growth factor receptors in breast cancer

Tumor Biology ◽  
2017 ◽  
Vol 39 (5) ◽  
pp. 101042831769837 ◽  
Author(s):  
Shuwei Wang ◽  
Zhongyang Ding
Keyword(s):  
Breast Cancer ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tyrosine Kinases ◽  
Growth Factor Receptor ◽  
Growth Factor Receptors ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors ◽  
Genetic Studies ◽  
The Common

Fibroblast growth factor receptors are growth factor receptor tyrosine kinases, exerting their roles in embryogenesis, tissue homeostasis, and development of breast cancer. Recent genetic studies have identified some subtypes of fibroblast growth factor receptors as strong genetic loci associated with breast cancer. In this article, we review the recent epidemiological findings and experiment results of fibroblast growth factor receptors in breast cancer. First, we summarized the structure and physiological function of fibroblast growth factor receptors in humans. Then, we discussed the common genetic variations in fibroblast growth factor receptors that affect breast cancer risk. In addition, we also introduced the potential roles of each fibroblast growth factor receptors isoform in breast cancer. Finally, we explored the potential therapeutics targeting fibroblast growth factor receptors for breast cancer. Based on the biological mechanisms of fibroblast growth factor receptors leading to the pathogenesis in breast cancer, targeting fibroblast growth factor receptors may provide new opportunities for breast cancer therapeutic strategies.

scholarly journals Fibroblast Growth Factor Receptor Functions in Glioblastoma

Cells ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 715 ◽  
Author(s):  
Ana Jimenez-Pascual ◽  
Florian A. Siebzehnrubl
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tyrosine Kinases ◽  
Therapeutic Potential ◽  
Growth Factor Receptor ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors ◽  
Comprehensive Overview ◽  
Tyrosine Kinase Signaling ◽  
Molecular Alterations

Glioblastoma is the most lethal brain cancer in adults, with no known cure. This cancer is characterized by a pronounced genetic heterogeneity, but aberrant activation of receptor tyrosine kinase signaling is among the most frequent molecular alterations in glioblastoma. Somatic mutations of fibroblast growth factor receptors (FGFRs) are rare in these cancers, but many studies have documented that signaling through FGFRs impacts glioblastoma progression and patient survival. Small-molecule inhibitors of FGFR tyrosine kinases are currently being trialed, underlining the therapeutic potential of blocking this signaling pathway. Nevertheless, a comprehensive overview of the state of the art of the literature on FGFRs in glioblastoma is lacking. Here, we review the evidence for the biological functions of FGFRs in glioblastoma, as well as pharmacological approaches to targeting these receptors.

scholarly journals The Acidic Domain and First Immunoglobulin-Like Loop of Fibroblast Growth Factor Receptor 2 Modulate Downstream Signaling through Glycosaminoglycan Modification

1999 ◽  
Vol 19 (10) ◽  
pp. 6754-6764 ◽  
Author(s):  
Kazushige Sakaguchi ◽  
Matthew V. Lorenzi ◽  
Donald P. Bottaro ◽  
Toru Miki
Keyword(s):  
Growth Factor ◽  
Heparan Sulfate ◽  
Fibroblast Growth Factor ◽  
Tyrosine Kinases ◽  
Mitogen Activated Protein Kinase ◽  
Alternative Exon ◽  
Protein Kinase Activity ◽  
Regulation Mechanism ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors

ABSTRACT Fibroblast growth factor receptors (FGFRs) are membrane-spanning tyrosine kinases that have been implicated in a variety of biological processes including mitogenesis, cell migration, development, and differentiation. We identified a unique isoform of FGFR2 expressed as a diffuse band with an unusually large molecular mass. This receptor is modified by glycosaminoglycan at a Ser residue located immediately N terminal to the acidic box, a stretch of acidic amino acids. The acidic box and the glycosaminoglycan modification site are encoded by an alternative exon of the FGFR2 gene. The acidic box appears to play an important role in glycosaminoglycan modification, and the presence of this domain is required for modification by heparan sulfate glycosaminoglycan. Moreover, the presence of the first immunoglobulin-like domain encoded by another alternative exon abrogated the modification. The high-affinity receptor with heparan sulfate modification enhanced receptor autophosphorylation, substrate phosphorylation, and ternary complex factor-independent gene expression. It also sustained mitogen-activated protein kinase activity and increased eventual DNA synthesis, a long-term response to fibroblast growth factor stimulation, at physiological ligand concentrations. We propose a novel regulation mechanism of FGFR2 signal transduction through glycosaminoglycan modification.

scholarly journals Fibroblast Growth Factor Receptors (FGFRs): Structures and Small Molecule Inhibitors

Cells ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 614 ◽  
Author(s):  
Shuyan Dai ◽  
Zhan Zhou ◽  
Zhuchu Chen ◽  
Guangyu Xu ◽  
Yongheng Chen
Keyword(s):  
Growth Factor ◽  
Urothelial Carcinoma ◽  
Fibroblast Growth Factor ◽  
Small Molecule ◽  
Tyrosine Kinases ◽  
Drug Targets ◽  
Small Molecule Inhibitors ◽  
Growth Factor Receptors ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors

Fibroblast growth factor receptors (FGFRs) are a family of receptor tyrosine kinases expressed on the cell membrane that play crucial roles in both developmental and adult cells. Dysregulation of FGFRs has been implicated in a wide variety of cancers, such as urothelial carcinoma, hepatocellular carcinoma, ovarian cancer and lung adenocarcinoma. Due to their functional importance, FGFRs have been considered as promising drug targets for the therapy of various cancers. Multiple small molecule inhibitors targeting this family of kinases have been developed, and some of them are in clinical trials. Furthermore, the pan-FGFR inhibitor erdafitinib (JNJ-42756493) has recently been approved by the U.S. Food and Drug Administration (FDA) for the treatment of metastatic or unresectable urothelial carcinoma (mUC). This review summarizes the structure of FGFR, especially its kinase domain, and the development of small molecule FGFR inhibitors.

Fibroblast growth factor receptor 4 (FGFR4) mediates signaling to the prolactin but not the FGFR4 promoter

2002 ◽  
Vol 283 (3) ◽  
pp. E490-E495 ◽  
Author(s):  
Shunjiang Yu ◽  
Lei Zheng ◽  
Sylvia L. Asa ◽  
Shereen Ezzat
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Functional Role ◽  
Promoter Activity ◽  
Fibroblast Growth Factor Receptor ◽  
Growth Factor Receptor ◽  
Dominant Negative ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors ◽  
Type Factor

Fibroblast growth factor receptors (FGFRs) have been implicated in a multitude of activities. Signaling of the 23 members of the FGF family is mediated through FGFR1–4. We show that FGF-19, which selectively binds FGFR4, can induce prolactin (PRL) but not growth hormone expression. FGF-19 also stimulated MAPK activation, an effect that was abrogated by a soluble dominant negative (dn) form of FGFR4. The response of the pituitary PRL promoter to FGF maps to an Ets-Pit1 binding site. We have previously shown that the hematopoietic zinc finger-containing transcription factor Ikaros (Ik) regulates FGFR4 as part of an overlapping site with that for an Ets-type factor in the FGFR4 promoter. Thus, we examined whether FGF-19 might regulate its own receptor through the Ets-Ik element in the FGFR4 promoter. Ets stimulated and dn-Ets inhibited basal FGFR4 and PRL promoter activity. In contrast, Ets enhanced FGF-19-induced PRL activation but failed to confer an effect for FGF-19 on the FGFR4 promoter. We conclude that FGFR4 mediates FGF-19 signaling to the PRL promoter. Our data also suggest a possible functional role for Ik in sorting Ets signals to the FGFR4 promoter, as distinct from the PRL promoter, where Ets partners with Pit1.

scholarly journals Members of the Fibroblast Growth Factor Receptor Superfamily Are Proteolytically Cleaved by Two Differently Activated Metalloproteases

2021 ◽  
Vol 22 (6) ◽  
pp. 3165
Author(s):  
Garima Dixit ◽  
Willow Schanz ◽  
Benjamin A. Pappas ◽  
Thorsten Maretzky
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Tyrosine Kinases ◽  
Biological Activities ◽  
Growth Factor Receptor ◽  
Cell Movement ◽  
Calcium Ionophore ◽  
Fibroblast Growth ◽  
Fibroblast Growth Factor Receptors ◽  
Cellular Processes

Fibroblast growth factor receptors (FGFRs) are a family of receptor tyrosine kinases that have been associated not only with various cellular processes, such as embryonic development and adult wound healing but also enhanced tumor survival, angiogenesis, and metastatic spread. Proteolytic cleavage of these single-pass transmembrane receptors has been suggested to regulate biological activities of their ligands during growth and development, yet little is known about the proteases responsible for this process. In this study, we monitored the release of membrane-anchored FGFRs 1, 2, 3, and 4 in cell-based assays. We demonstrate here that metalloprotease-dependent metalloprotease family, ADAM10 and ADAM17. Loss- and gain-of-function studies in murine embryonic fibroblasts showed that constitutive shedding as well as phorbol-ester-induced processing of FGFRs 1, 3, and 4 is mediated by ADAM17. In contrast, treatment with the calcium ionophore ionomycin stimulated ADAM10-mediated FGFR2 shedding. Cell migration assays with keratinocytes in the presence or absence of soluble FGFRs suggest that ectodomain shedding can modulate the function of ligand-induced FGFR signaling during cell movement. Our data identify ADAM10 and ADAM17 as differentially regulated FGFR membrane sheddases and may therefore provide new insight into the regulation of FGFR functions.

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