scholarly journals NKX3.1 Is Regulated by Protein Kinase CK2 in Prostate Tumor Cells

2006 ◽  
Vol 26 (8) ◽  
pp. 3008-3017 ◽  
Author(s):  
Xiang Li ◽  
Bin Guan ◽  
Sam Maghami ◽  
Charles J. Bieberich

ABSTRACT Diminished expression of NKX3.1 is associated with prostate cancer progression in humans, and in mice, loss of nkx3.1 leads to epithelial cell proliferation and altered gene expression patterns. The NKX3.1 amino acid sequence includes multiple potential phosphoacceptor sites for protein kinase CK2. To investigate posttranslational regulation of NKX3.1, phosphorylation of NKX3.1 by CK2 was studied. In vitro kinase assays followed by mass spectrometric analyses demonstrated that CK2 phosphorylated recombinant NKX3.1 on Thr89 and Thr93. Blocking CK2 activity in LNCaP cells with apigenin or 5,6-dichlorobenzimidazole riboside led to a rapid decrease in NKX3.1 accumulation that was rescued by proteasome inhibition. Replacing Thr89 and Thr93 with alanines decreased NKX3.1 stability in vivo. Small interfering RNA knockdown of CK2α′ but not CK2α also led to a decrease in NKX3.1 steady-state level. In-gel kinase assays and Western blot analyses using fractionated extracts of LNCaP cells demonstrated that free CK2α′ could phosphorylate recombinant human and mouse NKX3.1, whereas CK2α′ liberated from the holoenzyme could not. These data establish CK2 as a regulator of NKX3.1 in prostate tumor cells and provide evidence for functionally distinct pools of CK2α′ in LNCaP cells.

2003 ◽  
Vol 84 (2) ◽  
pp. 497-505 ◽  
Author(s):  
Yasuhiko Matsushita ◽  
Mayumi Ohshima ◽  
Kuniaki Yoshioka ◽  
Masamichi Nishiguchi ◽  
Hiroshi Nyunoya

2008 ◽  
Vol 312 (1-2) ◽  
pp. 61-69 ◽  
Author(s):  
Maciej Masłyk ◽  
Elżbieta Kochanowicz ◽  
Rafał Zieliński ◽  
Konrad Kubiński ◽  
Ulf Hellman ◽  
...  

2017 ◽  
Vol 72 (11-12) ◽  
pp. 459-465 ◽  
Author(s):  
Beatriz E. Boscán ◽  
Graciela L. Uzcanga ◽  
Maritza Calabokis ◽  
Rocío Camargo ◽  
Frank Aponte ◽  
...  

AbstractA polypeptide band with an apparent molecular weight of 55,000 was phosphorylated in vitro in whole-cell lysates ofTrypanosoma equiperdum. This band corresponds to tubulin as demonstrated by immunoprecipitation of the phosphorylated polypeptide fromT. equiperdumextracts when anti-α and anti-β tubulin monoclonal antibodies were employed. A parasite protein kinase CK2 was in charge of modifying tubulin given that common mammalian CK2 inhibitors such as emodin and GTP, hindered the phosphorylation of tubulin and exogenously added casein. Interestingly, a divalent cation-dependent translocation of theT. equiperdumtubulin and the CK2 responsible for its phosphorylation was noticed, suggesting a direct interaction between these two proteins. Additionally, this fraction of tubulin and its kinase coeluted using separations based on parameters as different as charge (DEAE-Sepharose anion-exchange chromatography) and size (Sephacryl S-300 gel filtration chromatography). Analyses by non-denaturing polyacrylamide gel electrophoresis and immunoblot of the purified and radioactively labeled fraction containing both tubulin and the CK2 enzyme, established the phosphorylation of a single band that was recognized by anti-CK2 α-subunit and anti-tubulin antibodies. All these findings revealed a physical association between a pool of tubulin and a CK2 inT. equiperdum.


2002 ◽  
Vol 364 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Maria RUZZENE ◽  
Daniele PENZO ◽  
Lorenzo A. PINNA

Incubation of Jurkat cells with 4,5,6,7-tetrabromobenzotriazole (TBB), a specific inhibitor of protein kinase CK2, induces dose-and time-dependent apoptosis as judged by several criteria. TBB-promoted apoptosis is preceded by inhibition of Ser/Thr phosphorylation of haematopoietic lineage cell-specific protein 1 (HS1) and is accompanied by caspase-dependent fragmentation of the same protein. Both effects are also observable if apoptosis is promoted by anti-Fas antibodies and by etoposide. Moreover, in vitro experiments show that HS1, once phosphorylated by CK2, becomes refractory to cleavage by caspase-3. These findings, in conjunction with similar data in the literature concerning two other CK2 protein substrates, Bid and Max, suggest that CK2 may play a general anti-apoptotic role through the generation of phosphorylated sites conferring resistance to caspase cleavage.


2021 ◽  
Vol 10 ◽  
Author(s):  
Ivy Chung ◽  
Kun Zhou ◽  
Courtney Barrows ◽  
Jacqueline Banyard ◽  
Arianne Wilson ◽  
...  

In American men, prostate cancer is the second leading cause of cancer-related death. Dissemination of prostate cancer cells to distant organs significantly worsens patients’ prognosis, and currently there are no effective treatment options that can cure advanced-stage prostate cancer. In an effort to identify compounds selective for metastatic prostate cancer cells over benign prostate cancer cells or normal prostate epithelial cells, we applied a phenotype-based in vitro drug screening method utilizing multiple prostate cancer cell lines to test 1,120 different compounds from a commercial drug library. Top drug candidates were then examined in multiple mouse xenograft models including subcutaneous tumor growth, experimental lung metastasis, and experimental bone metastasis assays. A subset of compounds including fenbendazole, fluspirilene, clofazimine, niclosamide, and suloctidil showed preferential cytotoxicity and apoptosis towards metastatic prostate cancer cells in vitro and in vivo. The bioavailability of the most discerning agents, especially fenbendazole and albendazole, was improved by formulating as micelles or nanoparticles. The enhanced forms of fenbendazole and albendazole significantly prolonged survival in mice bearing metastases, and albendazole-treated mice displayed significantly longer median survival times than paclitaxel-treated mice. Importantly, these drugs effectively targeted taxane-resistant tumors and bone metastases – two common clinical conditions in patients with aggressive prostate cancer. In summary, we find that metastatic prostate tumor cells differ from benign prostate tumor cells in their sensitivity to certain drug classes. Taken together, our results strongly suggest that albendazole, an anthelmintic medication, may represent a potential adjuvant or neoadjuvant to standard therapy in the treatment of disseminated prostate cancer.


Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1563 ◽  
Author(s):  
João Batista Maia Rocha Neto ◽  
Andrey Coatrini Soares ◽  
Rogério Aparecido Bataglioli ◽  
Olívia Carr ◽  
Carlos Alberto Rodrigues Costa ◽  
...  

The increasing need for point-of-care diagnosis has sparked the development of label-free sensing platforms, some of which are based on impedance measurements with biological cells. Here, interdigitated electrodes were functionalized with layer-by-layer (LbL) films of hyaluronan (HA) and chitosan (CHI) to detect prostatic tumor cells (PC3 line). The deposition of LbL films was confirmed with atomic force microscopy and polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS), which featured the vibrational modes of the HA top layer capable of interacting specifically with glycoprotein CD44 receptors overexpressed in tumor cells. Though the CHI/HA LbL films cannot be considered as a traditional biosensor due to their limited selectivity, it was possible to distinguish prostate tumor cells in the range from 50 to 600 cells/µL in in vitro experiments with impedance spectroscopy. This was achieved by treating the impedance data with information visualization methods, which confirmed the distinguishing ability of the films by observing the absence of false positives in a series of control experiments. The CD44–HA interactions may, therefore, be exploited in clinical analyses and point-of-care diagnostics for cancer, particularly if computational methods are used to process the data.


2019 ◽  
Vol 20 (23) ◽  
pp. 5951 ◽  
Author(s):  
Antonella Lettieri ◽  
Christian Borgo ◽  
Luca Zanieri ◽  
Claudio D’Amore ◽  
Roberto Oleari ◽  
...  

Protein kinase CK2 (CK2) is a highly conserved and ubiquitous kinase is involved in crucial biological processes, including proliferation, migration, and differentiation. CK2 holoenzyme is a tetramer composed by two catalytically active (α/α’) and two regulatory (β) subunits and exerts its function on a broad range of targets. In the brain, it regulates different steps of neurodevelopment, such as neural differentiation, neuritogenesis, and synaptic plasticity. Interestingly, CK2 mutations have been recently linked to neurodevelopmental disorders; however, the functional requirements of the individual CK2 subunits in neurodevelopment have not been yet investigated. Here, we disclose the role of CK2 on the migration and adhesion properties of GN11 cells, an established model of mouse immortalized neurons, by different in vitro experimental approaches. Specifically, the cellular requirement of this kinase has been assessed pharmacologically and genetically by exploiting CK2 inhibitors and by generating subunit-specific CK2 knockout GN11 cells (with a CRISPR/Cas9-based approach). We show that CK2α’ subunit has a primary role in increasing cell adhesion and reducing migration properties of GN11 cells by activating the Akt-GSK3β axis, whereas CK2α subunit is dispensable. Further, the knockout of the CK2β regulatory subunits counteracts cell migration, inducing dramatic alterations in the cytoskeleton not observed in CK2α’ knockout cells. Collectively taken, our data support the view that the individual subunits of CK2 play different roles in cell migration and adhesion properties of GN11 cells, supporting independent roles of the different subunits in these processes.


2005 ◽  
Vol 79 (5) ◽  
pp. 2700-2708 ◽  
Author(s):  
Nathalie Franck ◽  
Jacques Le Seyec ◽  
Christiane Guguen-Guillouzo ◽  
Lars Erdtmann

ABSTRACT Hepatitis C virus (HCV) nonstructural 2 (NS2) protein is a hydrophobic transmembrane protein, described to be involved in different functions, such as apoptosis inhibition and gene transcription modulation. We investigated here NS2 protein turnover and found that NS2 was rapidly degraded by the proteasome in different cell lines, as in primary human hepatocytes. Since posttranslational modifications can influence protein turnover, we looked for potential phosphoacceptor sites in NS2. Computational sequence analysis in combination with screening of NS2 point mutants revealed that serine residue 168 was critical for degradation. In the quest of a protein kinase for NS2, we identified by sequence analysis that the serine residue 168 was part of a consensus casein kinase 2 (CK2) recognition site (S/TXXE). This motif was highly conserved since it could be found in the NS2 primary consensus sequences from all HCV genotypes. To verify whether CK2 is involved in NS2 phosphorylation, we showed by an in vitro kinase assay that CK2 phosphorylated NS2, as far as this CK2 motif was conserved. Interestingly, NS2 became resistant to protein degradation when the CK2 motif was modified by a single point mutation. Furthermore, inhibition of CK2 activity by curcumin decreased NS2 phosphorylation in vitro and stabilized NS2 expression in HepG2 cells. Finally, we showed in Huh-7.5 replicon cells that NS2, expressed in the context of the HCV polyprotein, was also sensitive to both proteasome-mediated degradation and CK2 inhibitor treatment. We suggest that NS2 is a short-lived protein whose degradation by the proteasome is regulated in a phosphorylation-dependent manner through the protein kinase CK2.


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