scholarly journals Repurposing covalent EGFR/HER2 inhibitors for on-target degradation of human Tribbles 2 (TRIB2) pseudokinase

2018 ◽  
Author(s):  
Daniel M Foulkes ◽  
Dominic P Byrne ◽  
Fiona P Bailey ◽  
Samantha Ferries ◽  
Claire E Eyers ◽  
...  

ONE SENTENCE SUMMARYA Tribbles 2 pseudokinase small molecule screen led to the identification of known EGFR/HER2 inhibitors that alter the stability of TRIB2in vitroand lead to rapid on-target degradation of TRIB2 in human cancer cells.SHORT ABSTRACTTribbles 2 (TRIB2) is a cancer-associated pseudokinase with a diverse interactome, including the AKT signaling module. Substantial evidence demonstrates that TRIB2 dysregulation is important in multiple human tumors. The non-canonical TRIB2 pseudokinase domain contains a unique cysteine rich region and interacts with a peptide motif in its own C-terminal tail. We demonstrate that TRIB2 is a target for previously described small molecule protein kinase ‘inhibitors’, which were originally designed to inhibit the catalytic domain of EGFR/HER2 tyrosine kinases. Using thermal-shift assays and drug repurposing, we classify ligands that stabilize or destabilize the TRIB2 pseudokinase domain. TRIB2 destabilizing agents, including the clinical inhibitor afatinib, lead to rapid and on-target TRIB2 protein degradation in tumor cells, eliciting tractable effects on cell signaling and survival. Our data identifies leads for further development of TRIB2-degrading drugs and highlights compound-induced TRIB2 downregulation, which might be mechanistically relevant for other catalytically-deficient (pseudo)kinases targeted by small molecules.FULL ABSTRACTA major challenge associated with biochemical and cellular analysis of pseudokinases is the lack of target-validated small molecule ligands with which to probe molecular function. Human Tribbles 2 (TRIB2) is a cancer-associated pseudokinase with a diverse interactome, which includes the canonical AKT signaling module. There is substantial evidence that human TRIB2 is a therapeutic target in both solid tumors and blood cancers. The non-canonical TRIB2 pseudokinase domain contains a unique cysteine-rich region and interacts with a peptide motif in its own C-terminal tail, which was previously shown to drive interaction with cellular E3 ubiquitin ligases. In this study we demonstrate that TRIB2 is a target for previously described small molecule protein kinase inhibitors, which were originally designed to inhibit the canonical catalytic domain of the tyrosine kinases EGFR/HER2. Using a thermal-shift assay, we discovered TRIB2 ligands within the Published Kinase Inhibitor Set (PKIS), and employed a drug repurposing approach to classify compounds that either stabilize or destabilize TRIB2in vitro. Remarkably, TRIB2 destabilizing agents, including the clinical covalent drug afatinib, lead to rapid and on-target TRIB2 degradation in human cells, eliciting tractable effects on signaling and survival. Our data reveal the first drug-leads for development of TRIB2-degrading ligands, which will also be invaluable for unravelling the cellular mechanisms of TRIB2-based signaling. Our study highlights that small molecule-induced protein downregulation through drug ‘off-targets’ might be relevant for other inhibitors that serendipitously target pseudokinases.ABBREVIATIONSDSFDifferential Scanning FluorimetryEGFREpidermal Growth Factor ReceptorHER2Human Epidermal Growth Factor Receptor 2MSMass spectrometryMSTMicroScale ThermophoresisPKISPublished Kinase Inhibitors SetTRIB2Tribbles 2TSAThermal Stability Assay

2018 ◽  
Vol 11 (549) ◽  
pp. eaat7951 ◽  
Author(s):  
Daniel M. Foulkes ◽  
Dominic P. Byrne ◽  
Wayland Yeung ◽  
Safal Shrestha ◽  
Fiona P. Bailey ◽  
...  

A major challenge associated with biochemical and cellular analysis of pseudokinases is a lack of target-validated small-molecule compounds with which to probe function. Tribbles 2 (TRIB2) is a cancer-associated pseudokinase with a diverse interactome, including the canonical AKT signaling module. There is substantial evidence that human TRIB2 promotes survival and drug resistance in solid tumors and blood cancers and therefore is of interest as a therapeutic target. The unusual TRIB2 pseudokinase domain contains a unique cysteine-rich C-helix and interacts with a conserved peptide motif in its own carboxyl-terminal tail, which also supports its interaction with E3 ubiquitin ligases. We found that TRIB2 is a target of previously described small-molecule protein kinase inhibitors, which were originally designed to inhibit the canonical kinase domains of epidermal growth factor receptor tyrosine kinase family members. Using a thermal shift assay, we discovered TRIB2-binding compounds within the Published Kinase Inhibitor Set (PKIS) and used a drug repurposing approach to classify compounds that either stabilized or destabilized TRIB2 in vitro. TRIB2 destabilizing agents, including the covalent drug afatinib, led to rapid TRIB2 degradation in human AML cancer cells, eliciting tractable effects on signaling and survival. Our data reveal new drug leads for the development of TRIB2-degrading compounds, which will also be invaluable for unraveling the cellular mechanisms of TRIB2-based signaling. Our study highlights that small molecule–induced protein down-regulation through drug “off-targets” might be relevant for other inhibitors that serendipitously target pseudokinases.


2009 ◽  
Vol 29 (21) ◽  
pp. 5858-5871 ◽  
Author(s):  
Richard Marcotte ◽  
Lixin Zhou ◽  
Harold Kim ◽  
Calvin D. Roskelly ◽  
William J. Muller

ABSTRACT Previous studies have demonstrated that c-Src tyrosine kinase interacts specifically with ErbB2, but not with other members of the epidermal growth factor receptor (EGFR) family. To identify the site of interaction, we recently used a chimeric EGFR/ErbB2 receptor approach to show that c-Src requires the kinase region of ErbB2 for binding. Here, we demonstrate that retention of a conserved amino acid motif surrounding tyrosine 877 (referred to here as EGFRYHAD) is sufficient to confer binding to c-Src. Surprisingly the association of c-Src was not dependent on its SH2 or SH3 domain or on the phosphorylation or kinase activity of the receptor. We further show that the chimeric EGFRs that contain the Y877 motif are transforming in vitro and in vivo following ligand stimulation. Transformation was also partially dependent on sustained activation of Stat3. Finally, we demonstrate that EGFRs with mutations in the catalytic domain, originally identified in lung cancer and conferring increased sensitivity to gefitinib and erlotinib, two EGFR kinase inhibitors, gained the capacity to bind c-Src. Moreover, transformation by these EGFR mutants was inhibited by Src inhibitors regardless of their sensitivities to gefitinib and erlotinib. These observations have important implications for understanding the molecular basis for resistance to EGFR inhibitors and implicate c-Src as a critical signaling molecule in EGFR mutant-induced transformation.


eLife ◽  
2022 ◽  
Vol 11 ◽  
Author(s):  
James A Timmons ◽  
Andrew Anighoro ◽  
Robert J Brogan ◽  
Jack Stahl ◽  
Claes Wahlestedt ◽  
...  

Insulin resistance (IR) contributes to the pathophysiology of diabetes, dementia, viral infection, and cardiovascular disease. Drug repurposing (DR) may identify treatments for IR; however, barriers include uncertainty whether in vitro transcriptomic assays yield quantitative pharmacological data, or how to optimise assay design to best reflect in vivo human disease. We developed a clinical-based human tissue IR signature by combining lifestyle-mediated treatment responses (>500 human adipose and muscle biopsies) with biomarkers of disease status (fasting IR from >1200 biopsies). The assay identified a chemically diverse set of >130 positively acting compounds, highly enriched in true positives, that targeted 73 proteins regulating IR pathways. Our multi-gene RNA assay score reflected the quantitative pharmacological properties of a set of epidermal growth factor receptor-related tyrosine kinase inhibitors, providing insight into drug target specificity; an observation supported by deep learning-based genome-wide predicted pharmacology. Several drugs identified are suitable for evaluation in patients, particularly those with either acute or severe chronic IR.


2018 ◽  
Vol 475 (15) ◽  
pp. 2417-2433 ◽  
Author(s):  
Dominic P. Byrne ◽  
Yong Li ◽  
Krithika Ramakrishnan ◽  
Igor L. Barsukov ◽  
Edwin A. Yates ◽  
...  

Sulfation of carbohydrate residues occurs on a variety of glycans destined for secretion, and this modification is essential for efficient matrix-based signal transduction. Heparan sulfate (HS) glycosaminoglycans control physiological functions ranging from blood coagulation to cell proliferation. HS biosynthesis involves membrane-bound Golgi sulfotransferases, including HS 2-O-sulfotransferase (HS2ST), which transfers sulfate from the cofactor PAPS (3′-phosphoadenosine 5′-phosphosulfate) to the 2-O position of α-l-iduronate in the maturing polysaccharide chain. The current lack of simple non-radioactive enzyme assays that can be used to quantify the levels of carbohydrate sulfation hampers kinetic analysis of this process and the discovery of HS2ST inhibitors. In the present paper, we describe a new procedure for thermal shift analysis of purified HS2ST. Using this approach, we quantify HS2ST-catalysed oligosaccharide sulfation using a novel synthetic fluorescent substrate and screen the Published Kinase Inhibitor Set, to evaluate compounds that inhibit catalysis. We report the susceptibility of HS2ST to a variety of cell-permeable compounds in vitro, including polyanionic polar molecules, the protein kinase inhibitor rottlerin and oxindole-based RAF kinase inhibitors. In a related study, published back-to-back with the present study, we demonstrated that tyrosyl protein sulfotranferases are also inhibited by a variety of protein kinase inhibitors. We propose that appropriately validated small-molecule compounds could become new tools for rapid inhibition of glycan (and protein) sulfation in cells, and that protein kinase inhibitors might be repurposed or redesigned for the specific inhibition of HS2ST.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhimin Zhang ◽  
Xiaojuan Lian ◽  
Wei Xie ◽  
Jin Quan ◽  
Maojun Liao ◽  
...  

AbstractResistance to epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has become the main clinical challenge of advanced lung cancer. This research aimed to explore the role of PARP1-mediated autophagy in the progression of TKI therapy. PARP1-mediated autophagy was evaluated in vitro by CCK-8 assay, clonogenic assay, immunofluorescence, and western blot in the HCC-827, H1975, and H1299 cells treated with icotinib (Ico), rapamycin, and AZD2281 (olaparib) alone or in combination. Our results and GEO dataset analysis confirmed that PARP1 is expressed at lower levels in TKI-sensitive cells than in TKI-resistant cells. Low PARP1 expression and high p62 expression were associated with good outcomes among patients with NSCLC after TKI therapy. AZD2281 and a lysosomal inhibitor reversed resistance to Ico by decreasing PARP1 and LC3 in cells, but an mTOR inhibitor did not decrease Ico resistance. The combination of AZD2281 and Ico exerted a markedly enhanced antitumor effect by reducing PARP1 expression and autophagy in vivo. Knockdown of PARP1 expression reversed the resistance to TKI by the mTOR/Akt/autophagy pathway in HCC-827IR, H1975, and H1299 cells. PARP1-mediated autophagy is a key pathway for TKI resistance in NSCLC cells that participates in the resistance to TKIs. Olaparib may serve as a novel method to overcome the resistance to TKIs.


2018 ◽  
Author(s):  
Dominic P Byrne ◽  
Yong Li ◽  
Krithika Ramakrishnan ◽  
Igor L Barsukov ◽  
Edwin A Yates ◽  
...  

ABSTRACTSulphation of carbohydrate residues occurs on a variety of glycans destined for secretion, and this modification is essential for efficient matrix-based signal transduction. Heparan sulphate (HS) glycosaminoglycans control physiological functions ranging from blood coagulation to cell proliferation. HS biosynthesis involves membrane-bound Golgi sulphotransferases, including heparan sulphate 2-O-sulphotransferase (HS2ST), which transfers sulphate from the co-factor PAPS (3’-phosphoadenosine 5’-phosphosulphate) to the 2-Oposition of α-L-iduronate in the maturing oligosaccharide chain. The current lack of simple non-radioactive enzyme assays that can be used to quantify the levels of carbohydrate sulphation hampers kinetic analysis of this process and the discovery of HS2ST inhibitors. In this paper, we describe a new procedure for thermal shift analysis of purified HS2ST. Using this approach, we quantify HS2ST-catalyzed oligosaccharide sulphation using a novel synthetic fluorescent substrate and screen the Published Kinase Inhibitor Set (PKIS), to evaluate compounds that inhibit catalysis. We report the susceptibility of HS2ST to a variety of cell permeable compoundsin vitro, including polyanionic polar molecules, the protein kinase inhibitor rottlerin and oxindole-based RAF kinase inhibitors. In a related study, published back-to-back with this article, we demonstrate that Tyrosyl Protein Sulpho Tranferases (TPSTs) are also inhibited by a variety of protein kinase inhibitors. We propose that appropriately validated small molecule compounds could become new tools for rapid inhibition of glycan (and protein) sulphation in cells, and that protein kinase inhibitors might be repurposed or redesigned for the specific inhibition of HS2ST.SUMMARY STATEMENTWe report that HS2ST, which is a PAPS-dependent glycan sulphotransferase, can be assayed using a variety of novel biochemical procedures, including a non-radioactive enzyme-based assay that detects glycan substrate sulphation in real time. HS2ST activity can be inhibited by different classes of compounds, including known protein kinase inhibitors, suggesting new approaches to evaluate the roles of HS2ST-dependent sulphation with small molecules in cells.


2018 ◽  
Vol 18 (8) ◽  
pp. 1208-1217 ◽  
Author(s):  
Manal M. Kandeel ◽  
Aliaa M. Kamal ◽  
Bassem H. Naguib ◽  
Marwa S.A. Hassan

Aims: Tyrosine kinases and topoisomerase I are common target enzymes for the majority of the anticancer agents. In contrast to quinazolines and quinolines, kinase inhibitors and topoisomerase inhibitors incorporating cinnoline scaffold are relatively infrequent. Thus the aim of this work was to replace the former scaffolds with the latter one. Eighteen novel cinnoline derivatives were designed, synthesized and characterized using both microanalytical and spectral data. Methods: The cytotoxic activity of the new compounds was screened in vitro against both human breast cancer cells and normal breast cells. Results: The enzymatic inhibition activity of promising candidates against both epidermal growth factor receptor tyrosine kinase and topoisomerase I was accomplished. Conclusions: Cell cycle profiles were observed at IC50 doses of representative biologically active compounds. Compound 7 represented a new scaffold incorporating triazepinocinnoline ring system and showed outstanding cytotoxic activity against MCF-7 (0.049 µM), tyrosine kinase inhibition (0.22 µM), apoptosis percentage and the highest selectivity index.


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