scholarly journals Serine-Threonine Kinase Receptor-Associated Protein (STRAP) Knockout Decreases the Malignant Phenotype in Neuroblastoma Cell Lines

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3201
Author(s):  
Laura V Bownes ◽  
Adele P Williams ◽  
Raoud Marayati ◽  
Colin H Quinn ◽  
Sara C Hutchins ◽  
...  

Background: Serine-threonine kinase receptor-associated protein (STRAP) plays an important role in neural development but also in tumor growth. Neuroblastoma, a tumor of neural crest origin, is the most common extracranial solid malignancy of childhood and it continues to carry a poor prognosis. The recent discovery of the role of STRAP in another pediatric solid tumor, osteosarcoma, and the known function of STRAP in neural development, led us to investigate the role of STRAP in neuroblastoma tumorigenesis. Methods: STRAP protein expression was abrogated in two human neuroblastoma cell lines, SK-N-AS and SK-N-BE(2), using transient knockdown with siRNA, stable knockdown with shRNA lentiviral transfection, and CRISPR-Cas9 genetic knockout. STRAP knockdown and knockout cells were examined for phenotypic alterations in vitro and tumor growth in vivo. Results: Cell proliferation, motility, and growth were significantly decreased in STRAP knockout compared to wild-type cells. Indicators of stemness, including mRNA abundance of common stem cell markers Oct4, Nanog, and Nestin, the percentage of cells expressing CD133 on their surface, and the ability to form tumorspheres were significantly decreased in the STRAP KO cells. In vivo, STRAP knockout cells formed tumors less readily than wild-type tumor cells. Conclusion: These novel findings demonstrated that STRAP plays a role in tumorigenesis and maintenance of neuroblastoma stemness.

2021 ◽  
Vol 22 (12) ◽  
pp. 6565
Author(s):  
Jennifer H. Foster ◽  
Eveline Barbieri ◽  
Linna Zhang ◽  
Kathleen A. Scorsone ◽  
Myrthala Moreno-Smith ◽  
...  

Pevonedistat is a neddylation inhibitor that blocks proteasomal degradation of cullin–RING ligase (CRL) proteins involved in the degradation of short-lived regulatory proteins, including those involved with cell-cycle regulation. We determined the sensitivity and mechanism of action of pevonedistat cytotoxicity in neuroblastoma. Pevonedistat cytotoxicity was assessed using cell viability assays and apoptosis. We examined mechanisms of action using flow cytometry, bromodeoxyuridine (BrDU) and immunoblots. Orthotopic mouse xenografts of human neuroblastoma were generated to assess in vivo anti-tumor activity. Neuroblastoma cell lines were very sensitive to pevonedistat (IC50 136–400 nM). The mechanism of pevonedistat cytotoxicity depended on p53 status. Neuroblastoma cells with mutant (p53MUT) or reduced levels of wild-type p53 (p53si-p53) underwent G2-M cell-cycle arrest with rereplication, whereas p53 wild-type (p53WT) cell lines underwent G0-G1 cell-cycle arrest and apoptosis. In orthotopic neuroblastoma models, pevonedistat decreased tumor weight independent of p53 status. Control mice had an average tumor weight of 1.6 mg + 0.8 mg versus 0.5 mg + 0.4 mg (p < 0.05) in mice treated with pevonedistat. The mechanism of action of pevonedistat in neuroblastoma cell lines in vitro appears p53 dependent. However, in vivo studies using mouse neuroblastoma orthotopic models showed a significant decrease in tumor weight following pevonedistat treatment independent of the p53 status. Novel chemotherapy agents, such as the NEDD8-activating enzyme (NAE) inhibitor pevonedistat, deserve further study in the treatment of neuroblastoma.


1996 ◽  
Vol 16 (3) ◽  
pp. 998-1005 ◽  
Author(s):  
J Liu ◽  
Y Wu ◽  
G Z Ma ◽  
D Lu ◽  
L Haataja ◽  
...  

The first exon of the BCR gene encodes a new serine/threonine protein kinase. Abnormal fusion of the BCR and ABL genes, resulting from the formation of the Philadelphia chromosome (Ph), is the hallmark of Ph-positive leukemia. We have previously demonstrated that the Bcr protein is tyrosine phosphorylated within first-exon sequences by the Bcr-Abl oncoprotein. Here we report that in addition to tyrose 177 (Y-177), Y-360 and Y283 are phosphorylated in Bcr-Abl proteins in vitro. Moreover, Bcr tyrosine 360 is phosphorylated in vivo within both Bcr-Abl and Bcr. Bcr mutant Y177F had a greatly reduced ability to transphosphorylate casein and histone H1, whereas Bcr mutants Y177F and Y283F had wild-type activities. In contrast, the Y360F mutation had little effect on Bcr's autophosphorylation activity. Tyrosine-phosphorylated Bcr, phosphorylated in vitro by Bcr-Abl, was greatly inhibited in its serine/threonine kinase activity, impairing both auto- and transkinase activities of Bcr. Similarly, the isolation of Bcr from cells expressing Bcr-Abl under conditions that preserve phosphotyrosine residues also reduced Bcr's kinase activity. These results indicate that tyrosine 360 of Bcr is critical for the transphosphorylation activity of Bcr and that in Ph-positive leukemia, Bcr serine/threonine kinase activity is seriously impaired.


2020 ◽  
Author(s):  
Dhirendra Kumar Sharma ◽  
Subhash C. Bihani ◽  
Hari S Misra ◽  
Yogendra S. Rajpurohit

SummaryRqkA, a DNA damage responsive Serine / Threonine kinase is characterized for its role in DNA repair and cell division in D. radiodurans. It has a unique combination of a kinase domain at N-terminus and a WD40 type domain at C-terminus joined through a linker. WD40 domain is comprised of eight β propeller repeats held together via “tryptophan-docking motifs” and forming a typical ‘velcro’ closure structure. RqkA mutants lacking the WD40 region (hereafter referred to as WD mutant) could not complement RqkA loss in γ radiation resistance in D. radiodurans and lacked γ radiation mediated activation of kinase activity in vivo. WD mutants failed to phosphorylate its cognate substrate (e.g. DrRecA) in surrogate E. coli cells. Further, unlike wild type enzyme, the kinase activity of its WD40 mutants was not stimulated by Pyrroloquinoline quinine (PQQ) indicating the role of the WD motifs in PQQ interaction and stimulation of its kinase activity. Together, results highlighted the importance of the WD40 domain in the regulation of RqkA kinase signaling functions in vivo and thus the role of WD40 domain in the regulation of any STPK is the first time demonstrated in bacteria.ImportanceThis study highlights the importance of the WD40 domain in activity regulation and signaling activity of bacterial serine/ threonine kinase for the first time in the bacterial response to gamma radiation and DNA damage.


2014 ◽  
Vol 83 (2) ◽  
pp. 522-533 ◽  
Author(s):  
Nagaraja Theeya ◽  
Atri Ta ◽  
Sayan Das ◽  
Rahul S. Mandal ◽  
Oishee Chakrabarti ◽  
...  

Eukaryote-like serine/threonine kinases (eSTKs) constitute an important family of bacterial virulence factors. Genome analysis had predicted putative eSTKs inSalmonella entericaserovar Typhi, although their functional characterization and the elucidation of their role in pathogenesis are still awaited. We show here that the primary sequence and secondary structure of thet4519locus ofSalmonellaTyphi Ty2 have all the signatures of eukaryotic superfamily kinases.t4519encodes a ∼39-kDa protein (T4519), which shows serine/threonine kinase activitiesin vitro. Recombinant T4519 (rT4519) is autophosphorylated and phosphorylates the universal substrate myelin basic protein. Infection of macrophages results in decreased viability of the mutant (Ty2Δt4519) strain, which is reversed by gene complementation. Moreover, reactive oxygen species produced by the macrophages signal to the bacteria to induce T4519, which is translocated to the host cell cytoplasm. That T4519 may target a host substrate(s) is further supported by the activation of host cellular signaling pathways and the induction of cytokines/chemokines. Finally, the role of T4519 in the pathogenesis ofSalmonellaTyphi is underscored by the significantly decreased mortality of mice infected with the Ty2Δt4519strain and the fact that the competitive index of this strain for causing systemic infection is 0.25% that of the wild-type strain. This study characterizes the first eSTK ofSalmonellaTyphi and demonstrates its role in promoting phagosomal survival of the bacteria within macrophages, which is a key determinant of pathogenesis. This, to the best of our knowledge, is the first study to describe the essential role of eSTKs in thein vivopathogenesis ofSalmonellaspp.


2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Inyup Paik ◽  
Fulu Chen ◽  
Vinh Ngoc Pham ◽  
Ling Zhu ◽  
Jeong-Il Kim ◽  
...  

Abstract CONSTITUTIVELY PHOTOMORPHOGENIC1 (COP1) is a highly conserved E3 ubiquitin ligase from plants to animals and acts as a central repressor of photomorphogenesis in plants. SUPPRESSOR OF PHYA-105 1 family members (SPA1-SPA4) directly interact with COP1 and enhance COP1 activity. Despite the presence of a kinase domain at the N-terminus, no COP1-independent role of SPA proteins has been reported. Here we show that SPA1 acts as a serine/threonine kinase and directly phosphorylates PIF1 in vitro and in vivo. SPAs are necessary for the light-induced phosphorylation, ubiquitination and subsequent degradation of PIF1. Moreover, the red/far-red light photoreceptor phyB interacts with SPA1 through its C-terminus and enhances the recruitment of PIF1 for phosphorylation. These data provide a mechanistic view on how the COP1-SPA complexes serve as an example of a cognate kinase-E3 ligase complex that selectively triggers rapid phosphorylation and removal of its substrates, and how phyB modulates this process to promote photomorphogenesis.


2016 ◽  
Vol 8 (1) ◽  
pp. 12 ◽  
Author(s):  
Sung Hwa Shin ◽  
Eun Jeoung Lee ◽  
Sunghee Hyun ◽  
Dowonkyoung Park ◽  
Sang Sun Kang

Uncoordinated 51-like kinase 2 (ULK2) is a member of the serine/threonine kinase family that functions an essential role regulating autophagy in mammalian cells. As autophagy is implicated in normal cellular homeostasis and multiple diseases, better mechanisticinsight will drive thedevelopment of novel therapeutic approaches. Here, we present evidence that ULK2 interacts withYAP for its degradation and subcellular localization. A potential PPxY motif (328PPnY331) was identified, which is similar with the consensus PPxY motif in ULK2 S/P domain. TheP329A (PA) mutation in the PY motif of ULK2 abolished the YAP-ULK2 association.At first, we observed that ULK2 physically interacted to YAP in vivo and in vitro, using a pull-down approach. Secondly, ULK2 and YAP co- localized at the apical (or tight junction) membrane as visualized by confocal microscopy. Furthermore, the PA mutant substantially increased during autophagy than that of wild-type ULK2 or the P242A mutant in transient transfection assays. Thus, the association between ULK2 and YAP through the WW domain links autophagy and the Hippo signal transduction pathway.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Yufeng Zhang ◽  
Sheng Zhang ◽  
Yi Wang ◽  
Zhiqiang Yang ◽  
Zhe Chen ◽  
...  

Bone resorption diseases, including osteoporosis, are usually caused by excessive osteoclastogenesis. Unc-51-like autophagy activating kinase 1 (ULK1), a mammalian serine/threonine kinase, may participate in the regulation of bone homeostasis and osteolytic metastasis. In this study, ULK1 expression during osteoclastogenesis was detected with RT-PCR. We knocked down or overexpressed ULK1 through siRNA or lentiviral transduction in bone marrow macrophage (BMM). TRAP and phalloidin staining were performed to detect the osteoclastogenesis activity. Ovariectomized (OVX) mouse model of osteoporosis and a mouse of model osteoclast-induced bone resorption were applied to explore the role of ULK1 in bone resorption in vivo. The results showed that ULK1 expression was downregulated during osteoclast differentiation and was clinically associated with osteoporosis. ULK1 inhibited osteoclast differentiation in vitro. Knockdown of ULK1 expression activated phosphorylation of c-Jun N-terminal kinase (JNK) and spleen tyrosine kinase (Syk). Docking protein 3 (DOK3) was coexpressed with ULK1 during osteoclastogenesis. Downregulation of DOK3 offsets the effect of ULK1 on osteoclastogenesis and induced phosphorylation of JNK and Syk. Activation of ULK1 impeded bone loss in OVX mice with osteoporosis. Additionally, upregulation of ULK1 inhibited osteoclast-induced bone resorption in vivo. Therefore, our study reveals a novel ULK1/DOK3/Syk axis that regulates osteoclast differentiation and bone resorption, and targeting ULK1 is a potential therapeutic strategy for osteoporosis.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0246244
Author(s):  
Laura V. Bownes ◽  
Adele P. Williams ◽  
Raoud Marayati ◽  
Laura L. Stafman ◽  
Hooper Markert ◽  
...  

Investigation of the mechanisms responsible for aggressive neuroblastoma and its poor prognosis is critical to identify novel therapeutic targets and improve survival. Enhancer of Zeste Homolog 2 (EZH2) is known to play a key role in supporting the malignant phenotype in several cancer types and knockdown of EZH2 has been shown to decrease tumorigenesis in neuroblastoma cells. We hypothesized that the EZH2 inhibitor, GSK343, would affect cell proliferation and viability in human neuroblastoma. We utilized four long-term passage neuroblastoma cell lines and two patient-derived xenolines (PDX) to investigate the effects of the EZH2 inhibitor, GSK343, on viability, motility, stemness and in vivo tumor growth. Immunoblotting confirmed target knockdown. Treatment with GSK343 led to significantly decreased neuroblastoma cell viability, migration and invasion, and stemness. GSK343 treatment of mice bearing SK-N-BE(2) neuroblastoma tumors resulted in a significant decrease in tumor growth compared to vehicle-treated animals. GSK343 decreased viability, and motility in long-term passage neuroblastoma cell lines and decreased stemness in neuroblastoma PDX cells. These data demonstrate that further investigation into the mechanisms responsible for the anti-tumor effects seen with EZH2 inhibitors in neuroblastoma cells is warranted.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 10008-10008
Author(s):  
M. Regairaz ◽  
F. Munier ◽  
H. Sartelet ◽  
V. Marty ◽  
M. Castaing ◽  
...  

10008 Background: Activating mutations of the Anaplastic Lymphoma Kinase (ALK) receptor could be responsible for most familial neuroblastoma cases and for up to 15% of somatic cases. The objective of the present study was to further investigate the role of ALK activation in neuroblastoma. Methods: Tissue microarrays were constructed containing 101 primary tumors and 56 paired normal tissues. Sections were immunostained with anti-ALK or anti-P-ALK antibodies, and with antibodies directed against the ALK ligands: PTN (Pleiotrophin) or MDK (Midkine). The Wilcoxon signed rank test was applied for comparison of paired data. Associations with prognostic factors were analyzed using t-tests. Effects of the ALK inhibitor TAE684 (Novartis) on cell proliferation and signaling was evaluated in wild-type or mutated ALK neuroblastoma cell lines and xenografts. Results: ALK was expressed in about 100% of tumors and normal tissues, while phospho-ALK was detected in 5% of normal tissues and 50% of tumors. Sequencing of the kinase domain of ALK showed that its phosphorylation was largely independent of mutations and we found that MDK and PTN ligands were expressed in 66% and 50% of tumors, respectively. Interestingly, ALK, P-ALK, and MDK were expressed at higher levels in tumors as compared with paired normal tissues (p < 0.0001), while PTN showed an inverse tendency, being more expressed in normal tissues (p = 0.07). In tumors, P-ALK was associated with good-prognosis factors, including favorable stages (p = 0.01), absence of MYCN amplification (p = 0.05) and a younger age at diagnosis (p = 0.03). Inhibition of cell proliferation by TAE684 was detectible in all neuroblastoma cell lines, regardless of ALK status. However, TAE684 failed to demonstrate antitumor activity in advanced stage neuroblastoma xenografts expressing either a wild-type or a mutated ALK. Interestingly, ALK pathway activation (P-STAT3, P-AKT) was weak or barely detectible in these xenografts. Conclusions: ALK activation occurs during neuroblastoma oncogenesis, along with a concomitant switch between the expressions of PTN and MDK. However, ALK may not be a relevant therapeutic target since in vivo inhibition showed no antitumor activity. [Table: see text]


2020 ◽  
Vol 11 (9) ◽  
Author(s):  
Bianjiang Liu ◽  
Yin Sun ◽  
Min Tang ◽  
Chao Liang ◽  
Chi-Ping Huang ◽  
...  

Abstract The androgen receptor splicing variant 7 (ARv7) that lacks the ligand-binding domain is increasingly considered as a key player leading to enzalutamide (Enz) resistance in patients with prostate cancer (PCa). However, the detailed mechanisms of how ARv7 expression is regulated and whether it also needs other factors to induce maximal Enz resistance remain unclear. Here, we identified a microRNA, miR-361-3p, whose expression is lower in patients with recurrent PCa, could function via binding to the 3′UTR of ARv7, but not the wild type of AR, to suppress its expression to increase the Enz sensitivity. Importantly, we found that miR-361-3p could also bind to the 3′UTR of MAP kinase-interacting serine/threonine kinase 2 (MKNK2) to suppress its expression to further increase the Enz sensitivity. In turn, the increased Enz can then function via a feedback mechanism through altering the HIF-2α/VEGFA signaling to suppress the expression of miR-361-3p under hypoxia conditions. Preclinical studies using an in vivo mouse model with orthotopically xenografted CWR22Rv1 cells demonstrated that combining the Enz with the small molecule miR-361-3p would result in better suppression of the Enz-resistant PCa tumor progression. Together, these preclinical studies demonstrate that miR-361-3p can function via suppressing the expression of ARv7 and MKNK2 to maximally increase the Enz sensitivity, and targeting these newly identified Enz/miR-361-3p/ARv7 and/or Enz/miR-361-3p/MKNK2 signals with small molecules may help in the development of novel therapies to better suppress the CRPC in patients that already have developed the Enz resistance.


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