Mnk inhibitors: a patent review

2021 ◽  
Vol 10 (1) ◽  
pp. 25-35
Author(s):  
Ahmed M Abdelaziz ◽  
Mingfeng Yu ◽  
Shudong Wang

The alteration of mRNA translation has a crucial role in defining the changes in cellular proteome. The phosphorylation of eukaryotic initiation factor 4E by mitogen-activated protein kinase-interacting kinases (Mnks) leads to the release and translation of mRNAs of specific oncogenic proteins. In recent years, the efforts made by the pharmaceutical industry to develop novel chemical skeletons to create potent and selective Mnk inhibitors have been fruitful. The pyridone-aminal scaffold has been utilized to generate several series of Mnk inhibitors presented in multiple patent applications and research articles. Tomivosertib (eFT508) is one of the molecules with such scaffold. It is one of the first two Mnk inhibitors that entered clinical trials, and has displayed momentous activity against several solid and hematological cancers. The present compilation provides a succinct review of the current state of development of pyridone-aminal-derived Mnk inhibitors through the analysis of relevant patent applications filed in the last 5 years.

2020 ◽  
Vol 21 (8) ◽  
pp. 2967
Author(s):  
Celia Pinto-Díez ◽  
Raquel Ferreras-Martín ◽  
Rebeca Carrión-Marchante ◽  
Víctor M. González ◽  
María Elena Martín

The mitogen-activated protein kinase (MAPK)-interacting kinases (MNKs) are involved in oncogenic transformation and can promote metastasis and tumor progression. In human cells, there are four MNKs isoforms (MNK1a/b and MNK2a/b), derived from two genes by alternative splicing. These kinases play an important role controlling the expression of specific proteins involved in cell cycle, cell survival and cell motility via eukaryotic initiation factor 4E (eIF4E) regulation, but also through other substrates such as heterogeneous nuclear ribonucleoprotein A1, polypyrimidine tract-binding protein-associated splicing factor and Sprouty 2. In this review, we provide an overview of the role of MNK in human cancers, describing the studies conducted to date to elucidate the mechanism involved in the action of MNKs, as well as the development of MNK inhibitors in different hematological cancers and solid tumors.


2018 ◽  
Author(s):  
Senthilmurugan Ramalingam ◽  
Vidya P. Ramamurthy ◽  
Lalji K. Gediya ◽  
Francis N. Murigi ◽  
Puranik Purushottamachar ◽  
...  

ABSTRACTCurrently, there are no effective therapies for patients with triple-negative breast cancer (TNBC), an aggressive and highly metastatic disease. Activation of eukaryotic initiation factor 4E (eIF4E) by mitogen-activated protein kinase (MAPK)-interacting kinases 1 and 2 (Mnk1/2) play a critical role in the development, progression and metastasis of TNBC. Herein, we undertook a comprehensive study to evaluate the activity of a first-in-class Mnk1/2 protein degraders, in clinically relevant models of TNBC. These studies enabled us to identify racemic VNLG-152R as the most efficacious Mnk1/2 degrader. By targeting Mnk1/2 protein degradation (activity), VNLG-152R potently inhibited both Mnk-eIF4E and mTORC1 signaling pathways and strongly regulated downstream factors involved in cell cycle regulation, apoptosis, pro-inflammatory cytokines/chemokines secretion, epithelial-mesenchymal transition (EMT) and metastasis. Most importantly, orally bioavailable VNLG-152R exhibited remarkable antitumor and antimetastatic activities against cell line and patient-derived TNBC xenograft models, with no apparent host toxicity. Collectively, these studies demonstrate that targeting Mnk-eIF4E/mTORC1 signaling with a potent Mnk1/2 degrader, VNLG-152R, is a novel therapeutic strategy that can be developed as monotherapy for effective treatment of patients with primary/metastatic TNBC.


2001 ◽  
Vol 21 (3) ◽  
pp. 743-754 ◽  
Author(s):  
Gert C. Scheper ◽  
Nick A. Morrice ◽  
Miranda Kleijn ◽  
Christopher G. Proud

ABSTRACT The cap-binding translation initiation factor eukaryotic initiation factor 4E (eIF4E) is phosphorylated in vivo at Ser209 in response to a variety of stimuli. In this paper, we show that the mitogen-activated protein kinase (MAPK) signal-integrating kinase Mnk2 phosphorylates eIF4E at this residue. Mnk2 binds to the scaffolding protein eIF4G, and overexpression of Mnk2 results in increased phosphorylation of endogenous eIF4E, showing that it can act as an eIF4E kinase in vivo. We have identified eight phosphorylation sites in Mnk2, of which at least three potential MAPK sites are likely to be essential for Mnk2 activity. In contrast to that of Mnk1, the activity of overexpressed Mnk2 is high under control conditions and could only be reduced substantially by a combination of PD98059 and SB203580, while the activity of endogenous Mnk2 in Swiss 3T3 cells was hardly affected upon treatment with these inhibitors. These compounds did not abolish phosphorylation of eIF4E, implying that Mnk2 may mediate phosphorylation of eIF4E in Swiss 3T3 cells. In vitro phosphorylation studies show that Mnk2 is a significantly better substrate than Mnk1 for extracellular signal-regulated kinase 2 (ERK2), p38MAPKα, and p38MAPKβ. Therefore, the high levels of activity of Mnk2 under several conditions may be explained by efficient activation of Mnk2 by low levels of activity of the upstream kinases. Interestingly, we found that the association of both Mnk1 and Mnk2 with eIF4G increased upon inhibition of the MAPK pathways while activation of ERK resulted in decreased binding to eIF4G. This might reflect a mechanism to ensure rapid, but transient, phosphorylation of eIF4E upon stimulation of the MAPK pathways.


2010 ◽  
Vol 30 (21) ◽  
pp. 5160-5167 ◽  
Author(s):  
Mayya Shveygert ◽  
Constanze Kaiser ◽  
Shelton S. Bradrick ◽  
Matthias Gromeier

ABSTRACT The m7G cap binding protein eukaryotic initiation factor 4E (eIF4E) is a rate-limiting determinant of protein synthesis. Elevated eIF4E levels, commonly associated with neoplasia, promote oncogenesis, and phosphorylation of eIF4E at Ser209 is critical for its tumorigenic potential. eIF4E phosphorylation is catalyzed by mitogen-activated protein kinase (MAPK)-interacting serine/threonine kinase (Mnk), a substrate of Erk1/2 and p38 MAPKs. Interaction with the scaffolding protein eIF4G, which also binds eIF4E, brings Mnk and its substrate into physical proximity. Thus, Mnk-eIF4G interaction is important for eIF4E phosphorylation. Through coimmunoprecipitation assays, we showed that MAPK-mediated phosphorylation of the Mnk1 active site controls eIF4G binding. Utilizing a naturally occurring splice variant, we demonstrated that the C-terminal domain of Mnk1 restricts its interaction with eIF4G, preventing eIF4E phosphorylation in the absence of MAPK signaling. Furthermore, using a small-molecule Mnk1 inhibitor and kinase-dead mutant, we established that Mnk1 autoregulates its interaction with eIF4G, releasing itself from the scaffold after phosphorylation of its substrate. Our findings indicate tight control of eIF4E phosphorylation through modulation of Mnk1-eIF4G interaction.


2000 ◽  
Vol 20 (10) ◽  
pp. 3558-3567 ◽  
Author(s):  
Isabelle Mothe-Satney ◽  
Daqing Yang ◽  
Patrick Fadden ◽  
Timothy A. J. Haystead ◽  
John C. Lawrence

ABSTRACT Control of the translational repressor, PHAS-I, was investigated by expressing proteins with Ser/Thr → Ala mutations in the five (S/T)P phosphorylation sites. Results of experiments with HEK293 cells reveal at least three levels of control. At one extreme is nonregulated phosphorylation, exemplified by constitutive phosphorylation of Ser82. At an intermediate level, amino acids and insulin stimulate the phosphorylation of Thr36, Thr45, and Thr69 via mTOR-dependent processes that function independently of other sites in PHAS-I. At the third level, the extent of phosphorylation of one site modulates the phosphorylation of another. This control is represented by Ser64 phosphorylation, which depends on the phosphorylation of all three TP sites. The five sites have different influences on the electrophoretic properties of PHAS-I and on the affinity of PHAS-I for eukaryotic initiation factor 4E (eIF4E). Phosphorylation of Thr45 or Ser64 results in the most dramatic decreases in eIF4E binding in vitro. However, each of the sites influences mRNA translation, either directly by modulating the binding affinity of PHAS-I and eIF4E or indirectly by affecting the phosphorylation of other sites.


2006 ◽  
Vol 101 (2) ◽  
pp. 576-582 ◽  
Author(s):  
Stephen J. Crozier ◽  
Xueqian Zhang ◽  
Jufang Wang ◽  
Joseph Cheung ◽  
Scot R. Kimball ◽  
...  

Protein expression in the heart is altered following periods of myocardial ischemia. The changes in protein expression are associated with increased cell size that can be maladaptive. There is little information regarding the regulation of protein expression through the process of mRNA translation during ischemia and reperfusion in the heart. Therefore, the purpose of this study was to identify changes in signaling pathways and downstream regulatory mechanisms of mRNA translation in an in vivo model of myocardial ischemia and reperfusion. Hearts were collected from rats whose left main coronary arteries had either been occluded for 25 min or reversibly occluded for 25 min and subsequently reperfused for 15 min. Following reperfusion, both the phosphoinositide 3-kinase and mitogen-activated protein kinase pathways were activated, as evidenced by increased phosphorylation of Akt (PKB), extracellular signal-regulated kinase 1/2, and p38 mitogen-activated protein kinase. Activation of Akt stimulated signaling through the protein kinase mammalian target of rapamycin, as evidenced by increased phosphorylation of two of its effectors, the ribosomal protein S6 kinase and the eukaryotic initiation factor eIF4E binding protein 1. Ischemia and reperfusion also resulted in increased phosphorylation of eIF2 and eIF2B. These changes in protein phosphorylation suggest that control of mRNA translation following ischemia and reperfusion is modulated through a number of signaling pathways and regulatory mechanisms.


2000 ◽  
Vol 279 (4) ◽  
pp. E715-E729 ◽  
Author(s):  
O. Jameel Shah ◽  
Joshua C. Anthony ◽  
Scot R. Kimball ◽  
Leonard S. Jefferson

Maintenance of cellular protein stores in skeletal muscle depends on a tightly regulated synthesis-degradation equilibrium that is conditionally modulated under an extensive range of physiological and pathophysiological circumstances. Recent studies have established the initiation phase of mRNA translation as a pivotal site of regulation for global rates of protein synthesis, as well as a site through which the synthesis of specific proteins is controlled. The protein synthetic pathway is exquisitely sensitive to the availability of hormones and nutrients and employs a comprehensive integrative strategy to interpret the information provided by hormonal and nutritional cues. The translational repressor, eukaryotic initiation factor 4E binding protein 1 (4E-BP1), and the 70-kDa ribosomal protein S6 kinase (S6K1) have emerged as important components of this strategy, and together they coordinate the behavior of both eukaryotic initiation factors and the ribosome. This review discusses the role of 4E-BP1 and S6K1 in translational control and outlines the mechanisms through which hormones and nutrients effect changes in mRNA translation through the influence of these translational effectors.


2000 ◽  
Vol 278 (4) ◽  
pp. H1056-H1068 ◽  
Author(s):  
Lijun Wang ◽  
Xuemin Wang ◽  
Christopher G. Proud

Insulin acutely activates protein synthesis in ventricular cardiomyocytes from adult rats. In this study, we have established the methodology for studying the regulation of the signaling pathways and translation factors that may be involved in this response and have examined the effects of acute insulin treatment on them. Insulin rapidly activated the 70-kDa ribosomal S6 kinase (p70 S6k), and this effect was inhibited both by rapamycin and by inhibitors of phosphatidylinositol 3-kinase. The activation of p70 S6k is mediated by a signaling pathway involving the mammalian target of rapamycin (mTOR), which also modulates other translation factors. These include the eukaryotic initiation factor (eIF) 4E binding proteins (4E-BPs) and eukaryotic elongation factor 2 (eEF2). Insulin caused phosphorylation of 4E-BP1 and induced its dissociation from eIF4E, and these effects were also blocked by rapamycin. Concomitant with this, insulin increased the binding of eIF4E to eIF4G. Insulin also activated protein kinase B (PKB), which may lie upstream of p70 S6k and 4E-BP1, with the activation of the different isoforms being in the order α>β>γ. Insulin also caused inhibition of glycogen synthase kinase 3, which lies downstream of PKB, and of eEF2 kinase. The phosphorylation of eEF2 itself was also decreased by insulin, and this effect and the inactivation of eEF2 kinase were attenuated by rapamycin. The activation of overall protein synthesis by insulin in cardiomyocytes was substantially inhibited by rapamycin (but not by inhibitors of other specific signaling pathways, e.g., mitogen-activated protein kinase), showing that signaling events linked to mTOR play a major role in the control of translation by insulin in this cell type.


Sign in / Sign up

Export Citation Format

Share Document