scholarly journals PHA-680626 Is an Effective Inhibitor of the Interaction between Aurora-A and N-Myc

2021 ◽  
Vol 22 (23) ◽  
pp. 13122
Author(s):  
Dalila Boi ◽  
Fani Souvalidou ◽  
Davide Capelli ◽  
Federica Polverino ◽  
Grazia Marini ◽  
...  
Keyword(s):  
Cell Lines ◽  
Conformational Changes ◽  
Neuroblastoma Cells ◽  
Activation Loop ◽  
Aurora A ◽  
Kinase Activation ◽  
Proximity Ligation ◽  
Mitotic Kinase ◽  
Gene Coding

Neuroblastoma is a severe childhood disease, accounting for ~10% of all infant cancers. The amplification of the MYCN gene, coding for the N-Myc transcription factor, is an essential marker correlated with tumor progression and poor prognosis. In neuroblastoma cells, the mitotic kinase Aurora-A (AURKA), also frequently overexpressed in cancer, prevents N-Myc degradation by directly binding to a highly conserved N-Myc region. As a result, elevated levels of N-Myc are observed. During recent years, it has been demonstrated that some ATP competitive inhibitors of AURKA also cause essential conformational changes in the structure of the activation loop of the kinase that prevents N-Myc binding, thus impairing the formation of the AURKA/N-Myc complex. In this study, starting from a screening of crystal structures of AURKA in complexes with known inhibitors, we identified additional compounds affecting the conformation of the kinase activation loop. We assessed the ability of such compounds to disrupt the interaction between AURKA and N-Myc in vitro, using Surface Plasmon Resonance competition assays, and in tumor cell lines overexpressing MYCN, by performing Proximity Ligation Assays. Finally, their effects on N-Myc cellular levels and cell viability were investigated. Our results identify PHA-680626 as an amphosteric inhibitor both in vitro and in MYCN overexpressing cell lines, thus expanding the repertoire of known conformational disrupting inhibitors of the AURKA/N-Myc complex and confirming that altering the conformation of the activation loop of AURKA with a small molecule is an effective strategy to destabilize the AURKA/N-Myc interaction in neuroblastoma cancer cells.

scholarly journals A Focused Small-Molecule Screen Identifies PHA-680626 as an Amphosteric Inhibitor Disrupting the Interaction between Aurora-A and N-Myc

2021 ◽  
Author(s):  
Fani Souvalidou ◽  
Dalila Boi ◽  
Roberta Montanari ◽  
Federica Polverino ◽  
Grazia Marini ◽  
...  
Keyword(s):  
Cell Lines ◽  
Small Molecule ◽  
Conformational Changes ◽  
Neuroblastoma Cells ◽  
Activation Loop ◽  
Aurora A ◽  
Kinase Activation ◽  
Mitotic Kinase ◽  
Gene Coding

Neuroblastoma is a severe childhood disease, accounting for ≈10% of all infant cancers. The amplification of the MYCN gene, coding for the N-Myc transcriptional factor, is an essential marker correlated with tumor progression and poor prognosis. In neuroblastoma cells, the mitotic kinase Aurora-A (AURKA), also frequently overexpressed in cancer, prevents N-Myc degradation, by directly binding to a highly conserved N-Myc region, i.e. Myc Box I. As a result, elevated levels of N-Myc, which are required for the growth of MYCN amplified cells, are observed. During the last years, it has been demonstrated that the ATP competitive inhibitors of AURKA CD532, MLN8054 and Alisertib also cause essential conformational changes in the structure of the activation loop of the kinase that prevent N-Myc binding, thus impairing the formation of the AURKA/N-Myc complex. In this study, starting from a screening of crystal structures of AURKA in complex with known inhibitors, we identified additional compounds affecting the conformation of the kinase activation loop. We assessed the ability of such compounds to disrupt the interaction between AURKA and N-Myc in vitro, using Surface Plasmon Resonance competition assays, and in tumor cell lines overexpressing MYCN, by performing Proximity Ligation Assays. Finally, their effects on N-Myc cellular levels and cell viability were investigated. Our results, identifying PHA-680626 as an amphosteric inhibitor both in vitro and MYCN overexpressing cell lines, expand the repertoire of known conformational disrupting inhibitors of the AURKA/N-Myc complex, and confirm that altering the conformation of the activation loop of AURKA with a small molecule is an effective strategy to destabilize the AURKA/N-Myc interaction in neuroblastoma cancer cells.

scholarly journals Protein phosphatase 6 regulates mitotic spindle formation by controlling the T-loop phosphorylation state of Aurora A bound to its activator TPX2

2010 ◽  
Vol 191 (7) ◽  
pp. 1315-1332 ◽  
Author(s):  
Kang Zeng ◽  
Ricardo Nunes Bastos ◽  
Francis A. Barr ◽  
Ulrike Gruneberg
Keyword(s):  
Protein Phosphatase ◽  
Aurora A ◽  
Spindle Formation ◽  
Regulatory Subunits ◽  
Kinase Activation ◽  
Activator Proteins ◽  
Mitotic Kinase ◽  
General Importance ◽  
The Stability

Many protein kinases are activated by a conserved regulatory step involving T-loop phosphorylation. Although there is considerable focus on kinase activator proteins, the importance of specific T-loop phosphatases reversing kinase activation has been underappreciated. We find that the protein phosphatase 6 (PP6) holoenzyme is the major T-loop phosphatase for Aurora A, an essential mitotic kinase. Loss of PP6 function by depletion of catalytic or regulatory subunits interferes with spindle formation and chromosome alignment because of increased Aurora A activity. Aurora A T-loop phosphorylation and the stability of the Aurora A–TPX2 complex are increased in cells depleted of PP6 but not other phosphatases. Furthermore, purified PP6 acts as a T-loop phosphatase for Aurora A–TPX2 complexes in vitro, whereas catalytically inactive mutants cannot dephosphorylate Aurora A or rescue the PPP6C depletion phenotype. These results demonstrate a hitherto unappreciated role for PP6 as the T-loop phosphatase regulating Aurora A activity during spindle formation and suggest the general importance of this form of regulation.

scholarly journals Quantitative conformational profiling of kinase inhibitors reveals origins of selectivity for Aurora kinase activation states

2018 ◽  
Vol 115 (51) ◽  
pp. E11894-E11903 ◽  
Author(s):  
Eric W. Lake ◽  
Joseph M. Muretta ◽  
Andrew R. Thompson ◽  
Damien M. Rasmussen ◽  
Abir Majumdar ◽  
...  
Keyword(s):  
Large Scale ◽  
Kinase Inhibitors ◽  
Conformational Dynamics ◽  
Aurora Kinase ◽  
Activation Loop ◽  
Aurora A ◽  
Kinase Activation ◽  
Mitotic Kinase ◽  
Conformational Preferences ◽  
Wide Range

Protein kinases undergo large-scale structural changes that tightly regulate function and control recognition by small-molecule inhibitors. Methods for quantifying the conformational effects of inhibitors and linking them to an understanding of selectivity patterns have long been elusive. We have developed an ultrafast time-resolved fluorescence methodology that tracks structural movements of the kinase activation loop in solution with angstrom-level precision, and can resolve multiple structural states and quantify conformational shifts between states. Profiling a panel of clinically relevant Aurora kinase inhibitors against the mitotic kinase Aurora A revealed a wide range of conformational preferences, with all inhibitors promoting either the active DFG-in state or the inactive DFG-out state, but to widely differing extents. Remarkably, these conformational preferences explain broad patterns of inhibitor selectivity across different activation states of Aurora A, with DFG-out inhibitors preferentially binding Aurora A activated by phosphorylation on the activation loop, which dynamically samples the DFG-out state, and DFG-in inhibitors binding preferentially to Aurora A constrained in the DFG-in state by its allosteric activator Tpx2. The results suggest that many inhibitors currently in clinical development may be capable of differentiating between Aurora A signaling pathways implicated in normal mitotic control and in melanoma, neuroblastoma, and prostate cancer. The technology is applicable to a wide range of clinically important kinases and could provide a wealth of valuable structure–activity information for the development of inhibitors that exploit differences in conformational dynamics to achieve enhanced selectivity.

scholarly journals Detection of Ligand‐induced Conformational Changes in the Activation Loop of Aurora‐A Kinase by PELDOR Spectroscopy

ChemistryOpen ◽  
2016 ◽  
Vol 5 (6) ◽  
pp. 531-534 ◽  
Author(s):  
Selena G. Burgess ◽  
Maria Grazia Concilio ◽  
Richard Bayliss ◽  
Alistair J. Fielding
Keyword(s):  
Conformational Changes ◽  
Activation Loop ◽  
Aurora A Kinase ◽  
Aurora A

scholarly journals A Redox-Sensitive Thiol in Wis1 Modulates the Fission Yeast Mitogen-Activated Protein Kinase Response to H2O2 and Is the Target of a Small Molecule

2020 ◽  
Vol 40 (7) ◽  
Author(s):  
Johanna J. Sjölander ◽  
Agata Tarczykowska ◽  
Cecilia Picazo ◽  
Itziar Cossio ◽  
Itedale Namro Redwan ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Fission Yeast ◽  
Inhibitory Effect ◽  
Mitogen Activated Protein Kinase ◽  
Activation Loop ◽  
Content Type ◽  
Kinase Activation ◽  
Mitogen Activated Protein

ABSTRACT Oxidation of a highly conserved cysteine (Cys) residue located in the kinase activation loop of mitogen-activated protein kinase kinases (MAPKK) inactivates mammalian MKK6. This residue is conserved in the fission yeast Schizosaccharomyces pombe MAPKK Wis1, which belongs to the H2O2-responsive MAPK Sty1 pathway. Here, we show that H2O2 reversibly inactivates Wis1 through this residue (C458) in vitro. We found that C458 is oxidized in vivo and that serine replacement of this residue significantly enhances Wis1 activation upon addition of H2O2. The allosteric MAPKK inhibitor INR119, which binds in a pocket next to the activation loop and C458, prevented the inhibition of Wis1 by H2O2 in vitro and significantly increased Wis1 activation by low levels of H2O2 in vivo. We propose that oxidation of C458 inhibits Wis1 and that INR119 cancels out this inhibitory effect by binding close to this residue. Kinase inhibition through the oxidation of a conserved Cys residue in MKK6 (C196) is thus conserved in the S. pombe MAPKK Wis1.

scholarly journals Dynamic Equilibrium of the Aurora A Kinase Activation Loop Revealed by Single-Molecule Spectroscopy

2017 ◽  
Vol 56 (38) ◽  
pp. 11409-11414 ◽  
Author(s):  
James A. H. Gilburt ◽  
Hajrah Sarkar ◽  
Peter Sheldrake ◽  
Julian Blagg ◽  
Liming Ying ◽  
...  
Keyword(s):  
Single Molecule ◽  
Dynamic Equilibrium ◽  
Activation Loop ◽  
Single Molecule Spectroscopy ◽  
Aurora A Kinase ◽  
Aurora A ◽  
Kinase Activation

In vitro and in vivo activity of ATP-based kinase inhibitors AP23464 and AP23848 against activation-loop mutants of Kit

Blood ◽  
2005 ◽  
Vol 106 (1) ◽  
pp. 227-234 ◽  
Author(s):  
Amie S. Corbin ◽  
Shadmehr Demehri ◽  
Ian J. Griswold ◽  
Yihan Wang ◽  
Chester A. Metcalf ◽  
...  
Keyword(s):  
Cell Lines ◽  
Kinase Inhibitors ◽  
Therapeutic Potential ◽  
Systemic Mastocytosis ◽  
Myelogenous Leukemia ◽  
Therapeutic Window ◽  
Hematopoietic Progenitor Cell ◽  
Activation Loop

Oncogenic mutations of the Kit receptor tyrosine kinase occur in several types of malignancy. Juxtamembrane domain mutations are common in gastrointestinal stromal tumors, whereas mutations in the kinase activation loop, most commonly D816V, are seen in systemic mastocytosis and acute myelogenous leukemia. Kit activation-loop mutants are insensitive to imatinib mesylate and have been largely resistant to targeted inhibition. We determined the sensitivities of both Kit mutant classes to the adenosine triphosphate (ATP)–based inhibitors AP23464 and AP23848. In cell lines expressing activation-loop mutants, low-nM concentrations of AP23464 inhibited phosphorylation of Kit and its downstream targets Akt and signal transducer and activator of transcription 3 (STAT3). This was associated with cell-cycle arrest and apoptosis. Wild-type Kit–and juxtamembrane-mutant–expressing cell lines required considerably higher concentrations for equivalent inhibition, suggesting a therapeutic window in which cells harboring D816V Kit could be eliminated without interfering with normal cellular function. Additionally, AP23464 did not disrupt normal hematopoietic progenitor-cell growth at concentrations that inhibited activation-loop mutants of Kit. In a murine model, AP23848 inhibited activation-loop mutant Kit phosphorylation and tumor growth. Thus, AP23464 and AP23848 potently and selectively target activation-loop mutants of Kit in vitro and in vivo and could have therapeutic potential against D816V-expressing malignancies.

scholarly journals Parainfluenza Virus Type 1 Induces Epithelial IL-8 Production via p38-MAPK Signalling

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Miguel Ángel Galván Morales ◽  
Carlos Cabello Gutiérrez ◽  
Fidencio Mejía Nepomuceno ◽  
Leticia Valle Peralta ◽  
Elba Valencia Maqueda ◽  
...  
Keyword(s):  
Viral Replication ◽  
Cell Lines ◽  
Virus Type ◽  
Molecular Mechanisms ◽  
Parainfluenza Virus ◽  
Kinase Activation ◽  
Mitogen Activated Protein ◽  
Human Parainfluenza Virus

Human parainfluenza virus type 1 (HPIV-1) is the most common cause of croup in infants. The aim of this study was to describe molecular mechanisms associated with IL-8 production during HPIV-1 infection and the role of viral replication in MAPK synthesis and activation. Anin vitromodel of HPIV-1 infection in the HEp-2 and A549 cell lines was used; a kinetic-based ELISA for IL-8 detection was also used, phosphorylation of the mitogen-activated protein kinases (MAPKs) was identified by Western blot analysis, and specific inhibitors for each kinase were used to identify which MAPK was involved. Inactivated viruses were used to assess whether viral replication is required for IL-8 production. Results revealed a gradual increase in IL-8 production at different selected times, when phosphorylation of MAPK was detected. The secretion of IL-8 in the two cell lines infected with the HPIV-1 is related to the phosphorylation of the MAPK as well as viral replication. Inhibition of p38 suppressed the secretion of IL-8 in the HEp-2 cells. No kinase activation was observed when viruses were inactivated.

scholarly journals Evaluation of TH-Cre knock-in cell lines for detection and specific targeting of stem cell-derived dopaminergic neurons

2020 ◽  
Author(s):  
A Fiorenzano ◽  
J Nelander Wahlestedt ◽  
M Parmar
Keyword(s):  
Stem Cell ◽  
Cell Lines ◽  
Dopaminergic Neurons ◽  
Ethical Issues ◽  
Fetal Tissue ◽  
Cell Replacement Therapy ◽  
Progressive Degeneration ◽  
Gene Coding

AbstractThe focal and progressive degeneration of dopaminergic (DA) neurons in ventral midbrain has made Parkinson’s disease (PD) a particularly interesting target of cell-based therapies. However, ethical issues and limited tissue availability have so far hindered the widespread use of human fetal tissue in cell-replacement therapy. DA neurons derived from human pluripotent stem cells (hPSCs) offer unprecedented opportunities to access a renewable source of cells suitable for PD therapeutic applications. To better understand the functional properties of stem-cell derived DA neurons, we generated targeted hPSC lines with the gene coding for Cre recombinase knocked into the TH locus. When combined with flexed GFP, they serve as reporter cell lines able to identify and isolate TH+ neurons in vitro and after transplantation in vivo. These TH-Cre lines provide a valuable genetic tool to manipulate DA neurons useful for the design of more precise DA differentiation protocols and the study of these cells after transplantation in pre-clinical animal models of PD.

scholarly journals ALT Neuroblastoma Chemoresistance due to ATM Activation by Telomere Dysfunction is Reversible with the ATM Inhibitor AZD0156

2021 ◽  
Author(s):  
Balakrishna Koneru ◽  
Ahsan Farooqi ◽  
Thinhh H. Nguyen ◽  
Wan Hsi Chen ◽  
Ashly Hindle ◽  
...  
Keyword(s):  
Cell Lines ◽  
De Novo ◽  
Clinical Stage ◽  
Neuroblastoma Cell ◽  
Telomere Dysfunction ◽  
Atm Kinase ◽  
Kinase Activation ◽  
Neuroblastoma Cell Lines

AbstractCancers overcome replicative immortality by activating either telomerase or an alternative lengthening of telomeres (ALT) mechanism. ALT occurs in ∼ 25% of high-risk neuroblastomas and relapse or progression in ALT neuroblastoma patients during or after front-line therapy is frequent and almost uniformly fatal. Temozolomide + irinotecan is commonly used as salvage therapy for neuroblastoma. Patient-derived cell-lines and xenografts established from relapsed ALT neuroblastoma patients demonstrated de novo resistance to temozolomide + irinotecan (as SN-38 in vitro, P<0.05) and in vivo (mouse event-free survival (EFS) P<0.0001) relative to telomerase-positive neuroblastomas. We observed that ALT neuroblastoma cells manifest constitutive ATM kinase activation due to spontaneous telomere dysfunction while telomerase- positive tumors lacked constitutive ATM activation or spontaneous telomere DNA damage. We demonstrated that induction of telomere dysfunction resulted in ATM activation that in turn conferred resistance to temozolomide + SN-38 (4.2 fold-change in IC50, P<0.001). ATM kinase shRNA knock-down or inhibition using a clinical-stage small molecule inhibitor (AZD0156) reversed resistance to temozolomide + irinotecan in ALT neuroblastoma cell-lines in vitro (P<0.001) and in 4 ALT xenografts in vivo (EFS P<0.0001). AZD0156 showed modest to no enhancement of temozolomide + irinotecan activity in telomerase-positive neuroblastoma cell lines and xenografts. ATR inhibition using AZD6738 did not enhance temozolomide + SN-38 activity in ALT neuroblastoma cell lines. Thus, resistance to chemotherapy in ALT neuroblastoma occurs via ATM kinase activation and was reversed with the ATM inhibitor AZD0156. Combining AZD0156 with temozolomide + irinotecan warrants clinical testing in neuroblastoma.One Statement SummaryATM activation at telomeres confers resistance to DNA damaging chemotherapy in ALT neuroblastoma that was reversed with ATM knockdown or inhibition.

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