Search results for "FGFR1"
showing 9 items of 9 documents
Design, synthesis and biological evaluation of new anticancer drugs: FGFR inhibitors
2021
Fibroblast growth factor receptors (FGFRs) constitute a family of tyrosine kinases receptors (RTKs) that exert pivotal physiological functions in human embryonic and adult tissues. Hyperactivated FGFR signaling drives tumorigenesis in multiple cancer types, including lung and brain cancers. Great effort has been laid on the development of new compounds that specifically target the FGFR axis. However, cancer cell- based and microenvironmental resistance mechanisms against FGFR inhibitors often arise and are currently poorly understood. Furthermore, FGFR-targeted therapy often presents different side effects, e due to the broad biological spectrum of the FGFR signaling axis as well as to its …
Intrinsic fluorescence of the clinically approved multikinase inhibitor nintedanib reveals lysosomal sequestration as resistance mechanism in FGFR-dr…
2017
Background Studying the intracellular distribution of pharmacological agents, including anticancer compounds, is of central importance in biomedical research. It constitutes a prerequisite for a better understanding of the molecular mechanisms underlying drug action and resistance development. Hyperactivated fibroblast growth factor receptors (FGFRs) constitute a promising therapy target in several types of malignancies including lung cancer. The clinically approved small-molecule FGFR inhibitor nintedanib exerts strong cytotoxicity in FGFR-driven lung cancer cells. However, subcellular pharmacokinetics of this compound and its impact on therapeutic efficacy remain obscure. Methods 3-dimens…
Neuronal FGFR1 transactivation by inducing FGFR1/5-HT1A heteroreceptor complexes formation
2011
There are no clear data on the molecular mechanism by which the hippocampal 5-HT transmission contributes to the neuroprotective and antidepressant effects of 5-HT uptake blockers. Previously, we revealed that a 5-HT1A agonist may induce phosphorylation of FGFR1 and ERK1/2 in rat hippocampus independent of FGF-2, suggesting transactivation of FGFR1 tyrosine kinase in the absence of neurotrophic factor binding. As extension of previous work, using BRET analysis and coimmunoprecipitation in cellular models, FGFR1-5-HT1A heteroreceptor complexes have been demonstrated and agonist modulation characterized. In vitro assays on ERK1/2 phosphorylation in HEK cells and primary hippocampal cultures h…
FGF-2/FGFR1 neurotrophic system expression level and its basal activation do not account for the age-dependent decline of precursor cell proliferatio…
2010
It is largely accepted that neurogenesis in the adult brain decreases with age and reduced levels of local neurotrophic support is speculated to be a contributing factor. Among neurotrophic factors involved on neurogenesis, we focused our attention on the neurotrophic system fibroblast growth factor-2 (FGF-2) and its receptor FGFR1, a potent modulator of precursor cell proliferation. In the present work, we aimed to analyse if potential age-dependent changes of the FGF-2/FGFR1 neurotrophic system may give account for the age-dependent decline of precursor cell proliferation in the neurogenic region of the subventricular zone (SVZ) in the rat brain. Using in situ hybridization and western bl…
Serotonin receptor agonist treatment induces transactivation of fibroblast growth factor receptor-1 (FGFR1) tyrosine kinase in the rat hippocampal ne…
2010
Over the past decade, many examples of activation of receptor tyrosine kinases in response to G-protein coupled receptor signaling have been reported, indicating that there are alternative modes of receptor tyrosine kinase activation (transactivation) in the absence of neurotrophic factor binding. In the present work, we aimed to examine if 5-HT receptor subtype activation may induce fibroblast growth factor receptor-1 (FGFR1) phosphorylation through transactivation of tyrosine kinase. The study has been performed in young adult rats treated with the selective 5-HT1A receptor agonist 8-OHDPAT at the dose of 0.4 mg/kg/i.p.. FGFR1 phosphorylation was evaluated by immunoprecipitation and weste…
Interactions between cholinergic and fibroblast growth factor receptors in brain trophism and plasticity
2014
Acetylcholine, acting on both nicotinic receptors (nAChRs) and muscarinic receptors (mAChRs), plays a role in the regulation of synaptic plasticity, being involved in the regulation of cellular processes and cognitive functions, such as learning, memory and attention. Recently, G protein coupled receptors (GPCRs), including mAChRs, have been reported to transactivate tyrosine-kinase receptors (RTK), such as epidermal growth factor receptor (EGFR), and initiate their intracellular signaling. In this minireview we have first analysed the RTK transactivation mechanisms, involving cholinergic receptors, and thereafter the interplay between AChR and neurotrophic factor systems built up by FGF2 a…
Existence of muscarinic acetylcholine receptor (mAChR) and fibroblast growth factor receptor (FGFR) heteroreceptor complexes and their enhancement of…
2017
Abstract Background Recently, it was demonstrated that G-protein-coupled receptors (GPCRs) can transactivate tyrosine kinase receptors in absence of their ligands. In this work, driven by the observation that mAChRs and fibroblast growth factor receptors (FGFRs) share signalling pathways and regulation of brain functions, it was decided to explore whether mAChRs activation may transactivate FGFRs and, if so, to characterize the related trophic effects in cultured hippocampal neurons. Methods Oxotremorine-M transactivation of FGFRs and related trophic effects were tested in primary hippocampal neurons. Western blotting and in situ proximity ligation assay (PLA) were used to detect FGFR phosp…
Nicotine-induced fibroblast growth factor-2 restores the age-related decline of precursor cell proliferation in the subventricular zone of rat brain.
2007
Precursor cell proliferation is present in the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the dentate gyrus of the hippocampus of adult rat and persists during aging although at reduced levels. Previous studies have shown that acute intermittent nicotine treatment significantly increases fibroblast growth factor-2 (FGF-2) expression in several brain regions of aged rats. The aim of the present investigation was to test the hypothesis that nicotine-induced expression of FGF-2 may restore the age-related decline of precursor cell proliferation. It was first demonstrated that nicotine treatment increases both mRNA and protein FGF-2 in the SVZ of aged …
Agonist-induced formation of FGFR1 homodimers and signaling differ among members of the FGF family
2011
Fibroblast growth factor receptor 1 (FGFR1) is known to be activated by homodimerization in the presence of both the FGF agonist ligand and heparan sulfate glycosaminoglycan. FGFR1 homodimers in turn trigger a variety of downstream signaling cascades via autophosphorylation of tyrosine residues in the cytoplasmic domain of FGFR1. By means of Bioluminescence Energy Resonance Transfer (BRET) as a sign of FGFR1 homodimerization, we evaluated in HEK293T cells the effects of all known FGF agonist ligands on homodimer formation. A significant correlation between BRET(2) signaling and ERK1/2 phosphorylation was observed, leading to a further characterization of the binding and signaling properties…