scholarly journals FYN tyrosine kinase, a downstream target of receptor tyrosine kinases, modulates anti-glioma immune responses

2019 ◽  
Author(s):  
Andrea Comba ◽  
Patrick J Dunn ◽  
Anna E Argento ◽  
Padma Kadiyala ◽  
Maria Ventosa ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Glioma Cells ◽  
Genetically Engineered ◽  
Immune Reactivity ◽  
Downstream Target ◽  
Glioma Growth ◽  
Fyn Tyrosine Kinase

ABSTRACTBackgroundHigh grade gliomas are aggressive and immunosuppressive brain tumors. Molecular mechanisms that regulate the inhibitory immune tumor microenvironment (TME) and glioma progression remain poorly understood. FYN tyrosine kinase is a downstream target of the oncogenic receptor tyrosine kinases pathway and is overexpressed in human gliomas. FYN’s rolein vivoin glioma growth remains unknown. We investigated whether FYN regulates glioma initiation, growth and invasion.MethodsWe evaluated the role of FYN using genetically engineered mouse glioma models (GEMM). We also generated FYN knockdown stem cells to induce gliomas in immune-competent and immune-deficient mice (NSG, CD8−/−, CD4−/−). We analyzed molecular mechanism by RNA-Seq and bioinformatics analysis. Flow cytometry was used to characterize immune cellular infiltrates in the FYN knockdown glioma TME.ResultsWe demonstrate that FYN knockdown in diverse immune-competent GEMMs of glioma reduced tumor progression and significantly increased survival. Gene ontologies (GOs) analysis of differentially expressed genes in wild type vs. FYN knockdown gliomas showed enrichment of GOs related to immune reactivity. However, in NSG, CD8−/− and CD4−/− immune-deficient mice, FYN knockdown gliomas failed to show differences in survival. These data suggest that the expression of FYN in glioma cells reduces anti-glioma immune activation. Examination of glioma immune infiltrates by flow-cytometry displayed reduction in the amount and activity of immune suppressive myeloid derived cells (MDSCs) in the FYN glioma TME.ConclusionsGliomas employ FYN mediated mechanisms to enhance immune-suppression and promote tumor progression. We propose that FYN inhibition within glioma cells could improve the efficacy of anti-glioma immunotherapies.Key pointsInhibition of FYN tyrosine kinase in genetically engineered mouse glioma models delays tumor initiation and progression. The oncogenic effects of FYN in vivo are mediated by downregulation of anti-glioma immunity.Importance of the StudyFYN is an effector of receptor tyrosine kinases (RTK) signaling in glioma. However, its rolein vivoremains unknown. Our study demonstrates that FYN tyrosine kinase is a novel regulator of the anti-glioma immune response. We show that FYN inactivation suppresses glioma growth, increases survival, and enhances anti-tumor immune reactivity. Our findings suggest that suppressing the expression of FYN in glioma cells could provide a novel therapeutic target.

scholarly journals Fyn tyrosine kinase, a downstream target of receptor tyrosine kinases, modulates antiglioma immune responses

2020 ◽  
Vol 22 (6) ◽  
pp. 806-818 ◽  
Author(s):  
Andrea Comba ◽  
Patrick J Dunn ◽  
Anna E Argento ◽  
Padma Kadiyala ◽  
Maria Ventosa ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Tyrosine Kinase ◽  
Tumor Progression ◽  
Molecular Mechanisms ◽  
Glioma Cells ◽  
Genetically Engineered ◽  
Immune Reactivity ◽  
Downstream Target ◽  
Deficient Mice ◽  
Fyn Tyrosine Kinase

Abstract Background High-grade gliomas are aggressive and immunosuppressive brain tumors. Molecular mechanisms that regulate the inhibitory immune tumor microenvironment (TME) and glioma progression remain poorly understood. Fyn tyrosine kinase is a downstream target of the oncogenic receptor tyrosine kinase pathway and is overexpressed in human gliomas. Fyn’s role in vivo in glioma growth remains unknown. We investigated whether Fyn regulates glioma initiation, growth and invasion. Methods We evaluated the role of Fyn using genetically engineered mouse glioma models (GEMMs). We also generated Fyn knockdown stem cells to induce gliomas in immune-competent and immune-deficient mice (nonobese diabetic severe combined immunodeficient gamma mice [NSG], CD8−/−, CD4−/−). We analyzed molecular mechanism by RNA sequencing and bioinformatics analysis. Flow cytometry was used to characterize immune cellular infiltrates in the Fyn knockdown glioma TME. Results We demonstrate that Fyn knockdown in diverse immune-competent GEMMs of glioma reduced tumor progression and significantly increased survival. Gene ontology (GO) analysis of differentially expressed genes in wild-type versus Fyn knockdown gliomas showed enrichment of GOs related to immune reactivity. However, in NSG and CD8−/− and CD4−/− immune-deficient mice, Fyn knockdown gliomas failed to show differences in survival. These data suggest that the expression of Fyn in glioma cells reduces antiglioma immune activation. Examination of glioma immune infiltrates by flow cytometry displayed reduction in the amount and activity of immune suppressive myeloid derived cells in the Fyn glioma TME. Conclusions Gliomas employ Fyn mediated mechanisms to enhance immune suppression and promote tumor progression. We propose that Fyn inhibition within glioma cells could improve the efficacy of antiglioma immunotherapies.

ACh and adenosine activate PI3-kinase in rabbit hearts through transactivation of receptor tyrosine kinases

2002 ◽  
Vol 283 (6) ◽  
pp. H2322-H2330 ◽  
Author(s):  
Thomas Krieg ◽  
Qining Qin ◽  
Elizabeth C. McIntosh ◽  
Michael V. Cohen ◽  
James M. Downey
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Kinase Inhibitor ◽  
Growth Factor Receptor ◽  
Pi3 Kinase ◽  
Dependent Manner ◽  
Src Tyrosine Kinase ◽  
Akt Phosphorylation ◽  
Downstream Target

Adenosine and acetylcholine (ACh) trigger preconditioning through different signaling pathways. We tested whether either could activate myocardial phosphatidylinositol 3-kinase (PI3-kinase), a putative signaling protein in ischemic preconditioning. We used phosphorylation of Akt, a downstream target of PI3-kinase, as a reporter. Exposure of isolated rabbit hearts to ACh increased Akt phosphorylation 2.62 ± 0.33 fold ( P = 0.001), whereas adenosine caused a significantly smaller increase (1.52 ± 0.08 fold). ACh-induced activation of Akt was abolished by the tyrosine kinase blocker genistein indicating at least one tyrosine kinase between the muscarinic receptor and Akt. ACh-induced Akt activation was blocked by the Src tyrosine kinase inhibitor 4-amino-5-(4-chlorophenyl)-7-( t-butyl)pyrazolo[3,4- d]pyrimidine (PP2) and by 4-(3-chloroanilino)-6,7-dimethoxyquinazoline (AG-1478), an epidermal growth factor receptor (EGFR) inhibitor, suggesting phosphorylation of a receptor tyrosine kinase in an Src tyrosine kinase-dependent manner. ACh caused tyrosine phosphorylation of the EGFR, which could be blocked by PP2, thus supporting this receptor hypothesis. AG-1478 failed to block the cardioprotection of ACh, however, suggesting that other receptor tyrosine kinases might be involved. Therefore, Gi protein-coupled receptors can activate PI3-kinase/Akt through transactivation of receptor tyrosine kinases in an Src tyrosine kinase-dependent manner.

Anti-glioma Efficacy and Mechanism of Action of Tripolinolate A from Tripolium pannonicum

Planta Medica ◽  
2018 ◽  
Vol 84 (11) ◽  
pp. 786-794
Author(s):  
Weiyun Chai ◽  
Lu Chen ◽  
Xiao-Yuan Lian ◽  
Zhizhen Zhang
Keyword(s):  
Cell Cycle ◽  
Transcription Factors ◽  
Glioma Cells ◽  
Inhibitory Effect ◽  
Cell Cycle Regulators ◽  
Expression Levels ◽  
Multiple Tumor ◽  
Glioma Growth

AbstractTripolinolate A as a new bioactive phenolic ester was previously isolated from a halophyte of Tripolium pannonicum. However, the in vitro and in vivo anti-glioma effects and mechanism of tripolinolate A have not been investigated. This study has demonstrated that (1) tripolinolate A inhibited the proliferation of different glioma cells with IC50 values of 7.97 to 14.02 µM and had a significant inhibitory effect on the glioma growth in U87MG xenograft nude mice, (2) tripolinolate A induced apoptosis in glioma cells by downregulating the expressions of antiapoptotic proteins and arrested glioma cell cycle at the G2/M phase by reducing the expression levels of cell cycle regulators, and (3) tripolinolate A also remarkably reduced the expression levels of several glioma metabolic enzymes and transcription factors. All data together suggested that tripolinolate A had significant in vitro and in vivo anti-glioma effects and the regulation of multiple tumor-related regulators and transcription factors might be responsible for the activities of tripolinolate A against glioma.

Signaling in new directions

1995 ◽  
Vol 73 (3-4) ◽  
pp. 133-136 ◽  
Author(s):  
Haleh Vahidi Samiei
Keyword(s):  
Gene Expression ◽  
Signal Transduction ◽  
Tyrosine Kinase ◽  
Map Kinase ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Molecular Level ◽  
Clear Cut ◽  
New Directions

Many laboratories, using a variety of organisms, have contributed to deciphering the identity and the order of the components leading from ligand-bound receptor tyrosine kinases to various intracellular events, including changes in gene expression. The gaps have only been filled recently. This minireview summarizes the findings and points out the degree of conservation of the same pathway in distant organisms, both at the molecular level and in terms of the consecutive steps. The review also looks at points at which this pathway might be diverging and points onto which other pathways might be converging. These interactions are not always clear cut, and understanding them will be the challenge for the future.Key words: signal transduction, receptor tyrosine kinase, RAS, RAF, MAP kinase.

scholarly journals Mechanisms of Resistance to KRASG12C Inhibitors

Cancers ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 151
Author(s):  
Victoria Dunnett-Kane ◽  
Pantelis Nicola ◽  
Fiona Blackhall ◽  
Colin Lindsay
Keyword(s):  
Clinical Trials ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Current Evidence ◽  
Mechanisms Of Resistance ◽  
Ras Pathway ◽  
Early Evidence ◽  
Downstream Effectors ◽  
Direct Inhibitors

KRAS is one of the most common human oncogenes, but concerted efforts to produce direct inhibitors have largely failed, earning KRAS the title of “undruggable”. Recent efforts to produce subtype specific inhibitors have been more successful, and several KRASG12C inhibitors have reached clinical trials, including adagrasib and sotorasib, which have shown early evidence of efficacy in patients. Lessons from other inhibitors of the RAS pathway suggest that the effect of these drugs will be limited in vivo by the development of drug resistance, and pre-clinical studies of G12C inhibitors have identified evidence of this. In this review we discuss the current evidence for G12C inhibitors, the mechanisms of resistance to G12C inhibitors and potential approaches to overcome them. We discuss possible targets of combination therapy, including SHP2, receptor tyrosine kinases, downstream effectors and PD1/PDL1, and review the ongoing clinical trials investigating these inhibitors.

Eph/Ephrin signalling in skeletal muscle development and regeneration

2014 ◽  
Author(s):  
◽  
Danny A. Stark
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cells ◽  
Tyrosine Kinases ◽  
Muscle Development ◽  
Receptor Tyrosine Kinases ◽  
Repulsive Interaction ◽  
Type I ◽  
Ephrin Ligands

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Skeletal muscle can be isolated into 642 individual muscles and makes up to one third to one half of the mass of the human body. Each of these muscles is specified and patterned prenatally and after birth they will increase in size and take on characteristics suited to each muscle's unique function. To make the muscles functional, each muscle cell must be innervated by a motor neuron, which will also affect the characteristics of the mature muscle. In a healthy adult, muscles will maintain their specialized pattern and function during physiological homeostasis, and will also recapitulate them if the integrity or health of the muscle is disrupted. This repair and regeneration is dependent satellite cells, the skeletal muscle stem cells. In this dissertation, we study a family of receptor tyrosine kinases, Ephs, and their juxtacrine ephrin ligands in the context of skeletal muscle specification and regeneration. First, using a classical ephrin 'stripe' assay to test for contact-mediated repulsion, we found that satellite cells respond to a subset of ephrins with repulsive motility in vitro and that these forward signals through Ephs also promote patterning of differentiating myotubes parallel to ephrin stripes. This pattering can be replicated in a heterologous in vivo system (the hindbrain of the developing quail, where neural crest cells migrate in streams to the branchial arches, and in the forelimb of the developing quail, where presumptive limb myoblasts emigrate from the somite). Second, we present evidence that specific pairwise interactions between Eph receptor tyrosine kinases and ephrin ligands are required to ensure appropriate muscle innervation when it is originally set during postnatal development and when it is recapitulated after muscle or nerve trauma during adulthood. We show expression of a single ephrin, ephrin-A3, exclusively on type I (slow) myofibers shortly after birth, while its receptor EphA8 is only localized to fast motor endplates, suggesting a functional repulsive interaction for motor axon guidance and/or synaptogenesis. Adult EFNA3-/- mutant mice show a significant loss of slow myofibers, while misexpression of ephrin-A3 on fast myofibers results in a switch from a fast fiber type to slow in the context of sciatic nerve injury and regrowth. Third, we show that EphA7 is expressed on satellite cell derived myocytes in vitro, and marks both myocytes and regenerating myofibers in vivo. In the EPHA7 knockout mouse, we find a regeneration defect in a barium chloride injury model starting 3 days post injection in vivo, and that cultured mutant satellite cells are slow to differentiate and divide. Finally, we present other potential Ephs and ephrins that may affect skeletal muscle, such as EphB1 that is expressed on all MyHC-IIb fibers and a subset of MyHC-IIx fibers, and we show a multitude of Ephs and ephrins at the neuromuscular junction that appear to localize on specific myofibers and at different areas of the synapse. We propose that Eph/ephrin signaling, though well studied in development, continues to be important in regulating post natal development, regeneration, and homeostasis of skeletal muscle.

scholarly journals Helicobacter Pylori Targets the EPHA2 Receptor Tyrosine Kinase in Gastric Cells Modulating Key Cellular Functions

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 513 ◽  
Author(s):  
Marina Leite ◽  
Miguel S. Marques ◽  
Joana Melo ◽  
Marta T. Pinto ◽  
Bruno Cavadas ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Tyrosine Kinase ◽  
Signaling Pathways ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Receptor Activation ◽  
Degradation Pathway ◽  
Mrna Levels ◽  
H Pylori

Helicobacter pylori, a stomach-colonizing Gram-negative bacterium, is the main etiological factor of various gastroduodenal diseases, including gastric adenocarcinoma. By establishing a life-long infection of the gastric mucosa, H. pylori continuously activates host-signaling pathways, in particular those associated with receptor tyrosine kinases. Using two different gastric epithelial cell lines, we show that H. pylori targets the receptor tyrosine kinase EPHA2. For long periods of time post-infection, H. pylori induces EPHA2 protein downregulation without affecting its mRNA levels, an effect preceded by receptor activation via phosphorylation. EPHA2 receptor downregulation occurs via the lysosomal degradation pathway and is independent of the H. pylori virulence factors CagA, VacA, and T4SS. Using small interfering RNA, we show that EPHA2 knockdown affects cell–cell and cell–matrix adhesion, invasion, and angiogenesis, which are critical cellular processes in early gastric lesions and carcinogenesis mediated by the bacteria. This work contributes to the unraveling of the underlying mechanisms of H. pylori–host interactions and associated diseases. Additionally, it raises awareness for potential interference between H. pylori infection and the efficacy of gastric cancer therapies targeting receptors tyrosine kinases, given that infection affects the steady-state levels and dynamics of some receptor tyrosine kinases (RTKs) and their signaling pathways.

scholarly journals TrkB deubiquitylation by USP8 regulates receptor levels and BDNF-dependent neuronal differentiation

2020 ◽  
Vol 133 (24) ◽  
pp. jcs247841 ◽  
Author(s):  
Carlos Martín-Rodríguez ◽  
Minseok Song ◽  
Begoña Anta ◽  
Francisco J. González-Calvo ◽  
Rubén Deogracias ◽  
...  
Keyword(s):  
Neuronal Differentiation ◽  
Neurotrophic Factor ◽  
Tyrosine Kinases ◽  
Hippocampal Neurons ◽  
Receptor Tyrosine Kinases ◽  
Neurotrophin Receptor ◽  
C Terminus ◽  
Carboxyl Terminal

ABSTRACTUbiquitylation of receptor tyrosine kinases (RTKs) regulates both the levels and functions of these receptors. The neurotrophin receptor TrkB (also known as NTRK2), a RTK, is ubiquitylated upon activation by brain-derived neurotrophic factor (BDNF) binding. Although TrkB ubiquitylation has been demonstrated, there is a lack of knowledge regarding the precise repertoire of proteins that regulates TrkB ubiquitylation. Here, we provide mechanistic evidence indicating that ubiquitin carboxyl-terminal hydrolase 8 (USP8) modulates BDNF- and TrkB-dependent neuronal differentiation. USP8 binds to the C-terminus of TrkB using its microtubule-interacting domain (MIT). Immunopurified USP8 deubiquitylates TrkB in vitro, whereas knockdown of USP8 results in enhanced ubiquitylation of TrkB upon BDNF treatment in neurons. As a consequence of USP8 depletion, TrkB levels and its activation are reduced. Moreover, USP8 protein regulates the differentiation and correct BDNF-dependent dendritic formation of hippocampal neurons in vitro and in vivo. We conclude that USP8 positively regulates the levels and activation of TrkB, modulating BDNF-dependent neuronal differentiation.This article has an associated First Person interview with the first author of the paper.

scholarly journals Receptor Tyrosine Kinases and Their Signaling Pathways as Therapeutic Targets of Curcumin in Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Sareshma Sudhesh Dev ◽  
Syafiq Asnawi Zainal Abidin ◽  
Reyhaneh Farghadani ◽  
Iekhsan Othman ◽  
Rakesh Naidu
Keyword(s):  
Signaling Pathways ◽  
Cancer Progression ◽  
Tyrosine Kinases ◽  
Receptor Tyrosine Kinases ◽  
Surface Proteins ◽  
Downstream Signaling ◽  
Anti Cancer ◽  
Rtk Inhibitors

Receptor tyrosine kinases (RTKs) are transmembrane cell-surface proteins that act as signal transducers. They regulate essential cellular processes like proliferation, apoptosis, differentiation and metabolism. RTK alteration occurs in a broad spectrum of cancers, emphasising its crucial role in cancer progression and as a suitable therapeutic target. The use of small molecule RTK inhibitors however, has been crippled by the emergence of resistance, highlighting the need for a pleiotropic anti-cancer agent that can replace or be used in combination with existing pharmacological agents to enhance treatment efficacy. Curcumin is an attractive therapeutic agent mainly due to its potent anti-cancer effects, extensive range of targets and minimal toxicity. Out of the numerous documented targets of curcumin, RTKs appear to be one of the main nodes of curcumin-mediated inhibition. Many studies have found that curcumin influences RTK activation and their downstream signaling pathways resulting in increased apoptosis, decreased proliferation and decreased migration in cancer both in vitro and in vivo. This review focused on how curcumin exhibits anti-cancer effects through inhibition of RTKs and downstream signaling pathways like the MAPK, PI3K/Akt, JAK/STAT, and NF-κB pathways. Combination studies of curcumin and RTK inhibitors were also analysed with emphasis on their common molecular targets.

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