NPM-ALK Regulated GSK3β Phosphorylation Results in Mcl-1 and CDC25A Accumulation and Enhanced Oncogenic Potential

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 586-586
Author(s):  
Scott RP McDonnell ◽  
Steven R Hwang ◽  
Venkatesha Basrur ◽  
Kevin P Conlon ◽  
Damian Fermin ◽  
...  

Abstract Abstract 586 Anaplastic large cell lymphoma (ALCL) is the most common type of pediatric peripheral T-cell lymphoma. ALCLs are frequently characterized by translocations involving the anaplastic lymphoma kinase (ALK) gene. In 70–80% of these cases, the chromosomal aberration t(2;5)(p23;q35) results in the juxtaposition of ALK with nucleophosmin (NPM) and the subsequent expression of the NPM-ALK tyrosine kinase. NPM-ALK is an oncogenic tyrosine kinase which induces numerous signaling pathways that drive proliferation and abrogate apoptosis. However, the mechanisms that lead to activation of downstream growth regulatory molecules in ALCLs have not been completely elucidated. Using a mass spectrometry-based phosphoproteomic screen, we identified GSK3β, as a potential signaling mediator of NPM-ALK. Using a selective inhibitor of ALK, we demonstrated that the tyrosine kinase activity of ALK regulates the phosphorylation of GSK3β at serine-9 (pS9-GSK3β) in a time and dose-dependent manner. Expression of NPM-ALK in 293T cells led to increased phosphorylation of GSK3β at serine-9 compared to kinase-defective K210R mutant NPM-ALK but did not affect total GSK3β levels. Inducible knockdown of ALK in SU-DHL-1 cells also led to decreased phosphorylation of GSK3β at serine-9 without affecting total GSK3β levels. Selective inhibition of PI3Kδ by CAL-101 resulted in decreased phosphorylation of GSK3β at serine-9 in a dose dependent manner without affecting total GSK3β or NPM-ALK activity. Ablation of ALK kinase activity resulted in proteasomal degradation of GSK3β substrates Mcl-1 and CDC25A. This degradation was recovered upon chemical inhibition of GSK3β (GSK3 IX). To address the role of GSK3β in ALCL proliferation, WST-1 assay revealed that ALK inhibition resulted in a decrease in cell viability which was rescued by GSK3β inhibition. ALK inhibition resulted in significant cellular apoptosis as detected by propidium iodide and Annexin V staining followed by flow cytometry. This apoptotic response was rescued by GSK3β inhibition. The effect of GSK3β on cellular oncogenic potential was addressed by colony formation assay using ALCL-derived cell lines. While ALK inhibition resulted in decreased colony numbers, simultaneous ALK and GSK3β inhibition recovered colony numbers compared to ALK inhibition alone. Additionally, stable GSK3β knockdown conferred resistance to growth inhibitory effect of ALK inhibition as determined by colony formation assay. Furthermore, pS9-GSK3β and its known substrate, CDC25A were selectively expressed in neoplastic cells of ALK+ALCL tissue biopsies and showed a significant correlation (p<0.001). Conversely, ALK-ALCL tissue biopsies showed no significant correlation of pS9-GSK3β and CDC25A expression (p<0.2). Our results demonstrate that NPM-ALK signals through PI3K/AKT to phosphorylate GSK3β at serine-9. This phosphorylation inhibits GSK3β kinase activity which results in the accumulation of CDC25A and Mcl-1 thus providing growth advantage and protection from apoptosis. These findings provide support for the role of GSK3β as a novel mediator of NPM-ALK oncogenesis. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2005 ◽  
Vol 106 (12) ◽  
pp. 3907-3916 ◽  
Author(s):  
Chiara Ambrogio ◽  
Claudia Voena ◽  
Andrea D. Manazza ◽  
Roberto Piva ◽  
Ludovica Riera ◽  
...  

Translocations of the anaplastic lymphoma kinase (ALK) gene have been described in anaplastic large-cell lymphomas (ALCLs) and in stromal tumors. The most frequent translocation, t(2;5), generates the fusion protein nucleophosmin (NPM)–ALK with intrinsic tyrosine kinase activity. Along with transformation, NPM-ALK induces morphologic changes in fibroblasts and lymphoid cells, suggesting a direct role of ALK in cell shaping. In this study, we used a mass-spectrometry–based proteomic approach to search for proteins involved in cytoskeleton remodeling and identified p130Cas (p130 Crk-associated substrate) as a novel interactor of NPM-ALK. In 293 cells and in fibroblasts as well as in human ALK-positive lymphoma cell lines, NPM-ALK was able to bind p130Cas and to induce its phosphorylation. Both of the effects were dependent on ALK kinase activity and on the adaptor protein growth factor receptor–bound protein 2 (Grb2), since no binding or phosphorylation was found with the kinase-dead mutant NPM-ALKK210R or in the presence of a Grb2 dominant-negative protein. Phosphorylation of p130Cas by NPM-ALK was partially independent from Src (tyrosine kinase pp60c-src) kinase activity, as it was still detectable in Syf-/- cells. Finally, p130Cas-/- (also known as Bcar1-/-) fibroblasts expressing NPM-ALK showed impaired actin filament depolymerization and were no longer transformed compared with wild-type cells, indicating an essential role of p130Cas activation in ALK-mediated transformation.


2013 ◽  
Vol 09 (02) ◽  
pp. 149 ◽  
Author(s):  
Alejandro García-Regalado ◽  
Claudia Haydée González-De la Rosa ◽  
◽  

The anaplastic lymphoma kinase (ALK) is a receptor with tyrosine kinase activity, which regulates the development and maintenance of the nervous system. Mutations or amplification in ALK promote tumorogenesis and progression of diverse types of cancer, which makes it an attractive therapeutic target against cancer diseases. Inhibition of its tyrosine kinase activity with small molecules, such as crizotinib, reveals tumor reversion; however, secondary mutations and amplification of the gene mediate resistance to treatment. In this article, we discuss the emerging role of possible therapeutic targets that could overcome the resistance to ALK inhibition in cancer, such as inhibition of other kinases involved in the pathway, inhibition of ALK mutant proteins through the development of new drugs based on its crystallography, and the use of antibodies against ALK.


2002 ◽  
Vol 22 (7) ◽  
pp. 2398-2409 ◽  
Author(s):  
Suparna Mazumder ◽  
Bendi Gong ◽  
Quan Chen ◽  
Judith A. Drazba ◽  
Jeffrey C. Buchsbaum ◽  
...  

ABSTRACT Cyclin E/Cdk2 is a critical regulator of cell cycle progression from G1 to S in mammalian cells and has an established role in oncogenesis. Here we examined the role of deregulated cyclin E expression in apoptosis. The levels of p50-cyclin E initially increased, and this was followed by a decrease starting at 8 h after treatment with genotoxic stress agents, such as ionizing radiation. This pattern was mirrored by the cyclin E-Cdk2-associated kinase activity and a time-dependent expression of a novel p18-cyclin E. p18-cyclin E was induced during apoptosis triggered by multiple genotoxic stress agents in all hematopoietic tumor cell lines we have examined. The p18-cyclin E expression was prevented by Bcl-2 overexpression and by the general caspase and specific caspase 3 pharmacologic inhibitors zVAD-fluoromethyl ketone (zVAD-fmk) and N-acetyl-Asp-Glu-Val-Asp-aldehyde (DEVD-CHO), indicating that it was linked to apoptosis. A p18-cyclin E276-395 (where cyclin E276-395 is the cyclin E fragment containing residues 276 to 395) was reconstituted in vitro, with mutagenesis experiments, indicating that the caspase-dependent cleavage was at amino acid residues 272 to 275. Immunoprecipitation analyses of the ectopically expressed cyclin E1-275, cyclin E276-395 deletion mutants, and native p50-cyclin E demonstrated that caspase-mediated cyclin E cleavage eliminated interaction with Cdk2 and therefore inactivated the associated kinase activity. Overexpression of cyclin E276-395, but not of several other cyclin E mutants, specifically induced phosphatidylserine exposure and caspase activation in a dose-dependent manner, which were inhibited in Bcl-2-overexpressing cells or in the presence of zVAD-fmk. Apoptosis and generation of p18-cyclin E were significantly inhibited by overexpressing the cleavage-resistant cyclin E mutant, indicating a functional role for caspase-dependent proteolysis of cyclin E for apoptosis of hematopoietic tumor cells.


Cancers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1074 ◽  
Author(s):  
Stephen P. Ducray ◽  
Karthikraj Natarajan ◽  
Gavin D. Garland ◽  
Suzanne D. Turner ◽  
Gerda Egger

Anaplastic lymphoma kinase (ALK) is a tyrosine kinase involved in neuronal and gut development. Initially discovered in T cell lymphoma, ALK is frequently affected in diverse cancers by oncogenic translocations. These translocations involve different fusion partners that facilitate multimerisation and autophosphorylation of ALK, resulting in a constitutively active tyrosine kinase with oncogenic potential. ALK fusion proteins are involved in diverse cellular signalling pathways, such as Ras/extracellular signal-regulated kinase (ERK), phosphatidylinositol 3-kinase (PI3K)/Akt and Janus protein tyrosine kinase (JAK)/STAT. Furthermore, ALK is implicated in epigenetic regulation, including DNA methylation and miRNA expression, and an interaction with nuclear proteins has been described. Through these mechanisms, ALK fusion proteins enable a transcriptional programme that drives the pathogenesis of a range of ALK-related malignancies.


1997 ◽  
Vol 273 (6) ◽  
pp. F931-F938 ◽  
Author(s):  
Goutam Ghosh Choudhury ◽  
C. Karamitsos ◽  
James Hernandez ◽  
Alessandra Gentilini ◽  
John Bardgette ◽  
...  

Proliferation and migration are important biological responses of mesangial cells to injury. Platelet-derived growth factor (PDGF) is a prime candidate to mediate these responses in glomerular disease. PDGF and its receptor (PDGFR) are upregulated in the mesangium during glomerular injury. We have recently shown that PDGF activates phosphatidylinositol 3-kinase (PI-3-kinase) in cultured mesangial cells. The role of this enzyme and other more distal signaling pathways in regulating migration and proliferation of mesangial cells has not yet been addressed. In this study, we used two inhibitors of PI-3-kinase, wortmannin (WMN) and LY-294002, to investigate the role of this enzyme in these processes. Pretreatment of mesangial cells with WMN and LY-294002 dose-dependently inhibited PDGF-induced PI-3-kinase activity assayed in antiphosphotyrosine immunoprecipitates. WMN pretreatment also inhibited the PI-3-kinase activity associated with anti-PDGFRβ immunoprecipitates prepared from mesangial cells treated with PDGF. Pretreatment of the cells with different concentrations of WMN resulted in a dose-dependent inhibition of PDGF-induced DNA synthesis. Both WMN and LY-294002 inhibited PDGF-stimulated migration of mesangial cells in a dose-dependent manner. It has recently been shown that PI-3-kinase physically interacts with Ras protein. Because Ras is an upstream regulator of the kinase cascade leading to the activation of mitogen-activated protein kinase (MAPK), we determined whether activation of PI-3-kinase is necessary for activation of MAPK. Pretreatment of mesangial cells with WMN and LY-294002 significantly inhibited PDGF-induced MAPK activity as measured by immune complex kinase assay of MAPK immunoprecipitates. Furthermore, PD-098059, an inhibitor of MAPK-activating kinase inhibited PDGF-induced MAPK activity and resulted in significant reduction of mesangial cell migration in response to PDGF. These data indicate that MAPK is a downstream target of PI-3-kinase and that both these enzymes are involved in regulating proliferation and migration of mesangial cells.


2019 ◽  
Vol 17 (4) ◽  
pp. 426-431
Author(s):  
Jin Xuezhu ◽  
Li Jitong ◽  
Nie Leigang ◽  
Xue Junlai

The main purpose of this study is to investigate the role of citrus leaf extract in carbon tetrachloride-induced hepatic injury and its potential molecular mechanism. Carbon tetrachloride was used to construct hepatic injury animal model. To this end, rats were randomly divided into 4 groups: control, carbon tetrachloride-treated, and two carbon tetrachloride + citrus leaf extract-treated groups. The results show that citrus leaf extract treatment significantly reversed the effects of carbon tetrachloride on the body weight changes and liver index. Besides, treatment with citrus leaf extract also reduced the levels of serum liver enzymes and oxidative stress in a dose-dependent manner. H&E staining and western blotting suggested that citrus leaf extract could repair liver histological damage by regulating AMPK and Nrf-2.


2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.


1990 ◽  
Vol 123 (2) ◽  
pp. 218-224 ◽  
Author(s):  
Xiangbing Wang ◽  
Noriyuki Sato ◽  
Monte A. Greer ◽  
Susan E. Greer ◽  
Staci McAdams

Abstract. The mechanism by which 30% medium hyposmolarity induces PRL secretion by GH4C1 cells was compared with that induced by 100 nmol/l TRH or 30 mmol/l K+. Removing medium Ca2+, blocking Ca2+ channels with 50 μmol/l verapamil, or inhibiting calmodulin activation with 20 μmol/l trifluoperazine, 10 μmol/l chlorpromazine or 10 μmol/l pimozide almost completely blocked hyposmolarity-induced secretion. The smooth muscle relaxant, W-7, which is believed relatively specific in inhibiting the Ca2+-calmodulin interaction, depressed hyposmolarity-induced PRL secretion in a dose-dependent manner (r = −0.991, p<0.01 ). The above drugs also blocked or decreased high K+-induced secretion, but had much less effect on TRH-induced secretion. Secretion induced by TRH, hyposmolarity, or high K+ was optimal at pH 7.3-7.65 and was significantly depressed at pH 6.0 or 8.0, indicating that release of hormone induced by all 3 stimuli is due to an active cell process requiring a physiologic extracellular pH and is not produced by nonspecific cell toxicity. The data suggest hyposmolarity and high K+ may share some similarities in their mechanism of stimulating secretion, which is different from that of TRH.


2009 ◽  
Vol 29 (12) ◽  
pp. 3367-3378 ◽  
Author(s):  
Scott A. Robertson ◽  
Rositsa I. Koleva ◽  
Lawrence S. Argetsinger ◽  
Christin Carter-Su ◽  
Jarrod A. Marto ◽  
...  

ABSTRACT Jak2, the cognate tyrosine kinase for numerous cytokine receptors, undergoes multisite phosphorylation during cytokine stimulation. To understand the role of phosphorylation in Jak2 regulation, we used mass spectrometry to identify numerous Jak2 phosphorylation sites and characterize their significance for Jak2 function. Two sites outside of the tyrosine kinase domain, Tyr317 in the FERM domain and Tyr637 in the JH2 domain, exhibited strong regulation of Jak2 activity. Mutation of Tyr317 promotes increased Jak2 activity, and the phosphorylation of Tyr317 during cytokine signaling requires prior activation loop phosphorylation, which is consistent with a role for Tyr317 in the feedback inhibition of Jak2 kinase activity after receptor stimulation. Comparison to several previously identified regulatory phosphorylation sites on Jak2 revealed a dominant role for Tyr317 in the attenuation of Jak2 signaling. In contrast, mutation of Tyr637 decreased Jak2 signaling and activity and partially suppressed the activating JH2 V617F mutation, suggesting a role for Tyr637 phosphorylation in the release of JH2 domain-mediated suppression of Jak2 kinase activity during cytokine stimulation. The phosphorylation of Tyr317 and Tyr637 act in concert with other regulatory events to maintain appropriate control of Jak2 activity and cytokine signaling.


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