scholarly journals The role of IKK in constitutive activation of NF-κB transcription factor in prostate carcinoma cells

2002 ◽  
Vol 115 (1) ◽  
pp. 141-151 ◽  
Author(s):  
Alexander V. Gasparian ◽  
Ya Juan Yao ◽  
Dariusz Kowalczyk ◽  
Ludmila A. Lyakh ◽  
Apollon Karseladze ◽  
...  
Keyword(s):  
Cell Lines ◽  
Prostate Carcinoma ◽  
Dominant Negative ◽  
Kinase Assay ◽  
Normal Prostate ◽  
Constitutive Activation ◽  
Prostate Epithelial Cells ◽  
Induced Apoptosis ◽  
Androgen Independent

Rel/NF-κB transcription factors are implicated in the control of cell proliferation, apoptosis and transformation. The key to NF-κB regulation is the inhibitory IκB proteins. During response to diverse stimuli, IκBs are rapidly phosphorylated by IκB kinases (IKKs), ubiquitinated and undergo degradation. We have investigated the expression and function of NF-κB, IκB inhibitors and IKKs in normal prostate epithelial cells and prostate carcinoma (PC) cell lines LNCaP, MDA PCa 2b, DU145, PC3, and JCA1. We found that NF-κB was constitutively activated in human androgen-independent PC cell lines DU145, PC3, JCA1 as well as androgen-independent CL2 cells derived from LNCaP. In spite of a strong difference in constitutive κB binding, Western blot analysis did not reveal any significant variance in the expression of p50, p65, IκBs, IKKα, and IKKβ between primary prostate cells, androgen-dependent and androgen-independent PC cells. However, we found that in androgen-independent PC cells IκBα was heavily phosphorylated and displayed a faster turnover. Using an in vitro kinase assay we demonstrated constitutive activation of IKK in androgen-independent PC cell lines. Blockage of NF-κB activity in PC cells by dominant-negative IκBα resulted in increased constitutive and TNF-α-induced apoptosis. Our data suggest that increased IKK activation leads to the constitutive activation of NF-κB ‘survival signaling’ pathway in androgen-independent PC cells. This may be important for the support of their androgen-independent status and growth advantage.

Oncogenic AKT Signaling Negatively Regulates Glucocorticoid Receptor Function to Promote Glucocorticoid Resistance In T Cell Acute Lymphoblastic Leukemia

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 11-11 ◽  
Author(s):  
Erich Piovan ◽  
Jiyang Yu ◽  
Pedro Real ◽  
Gawinowicz Mary Ann ◽  
Andrea Califano ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
Glucocorticoid Receptor ◽  
Cell Lines ◽  
Lymphoblastic Leukemia ◽  
Akt Signaling ◽  
Glucocorticoid Resistance ◽  
Akt Pathway ◽  
Constitutive Activation ◽  
Induced Apoptosis

Abstract Abstract 11 Glucocorticoids (GC) play a fundamental role in the treatment of all lymphoid tumors because of their capacity to induce apoptosis in lymphoid progenitor cells. The importance of GC therapy in lymphoid malignancies is underscored by the strong association of GC response with prognosis in childhood acute lymphoblastic leukemia (ALL). Thus, resistance to glucocorticoids is a well recognized feature of poor prognosis in the treatment of childhood ALL. A number of different mechanisms contributing to GC resistance in T-ALL have been proposed including increased expression of antiapoptotic factors such as MCL1, insufficient expression of the glucocorticoid receptor gene (NR3C1), expression of NR3C1 splice variants and loss of NR3C1 auto up-regulation. The development of strategies to reverse glucocorticoid resistance could have a profound impact on the treatment of ALL. Recently, we have showed that inhibition of NOTCH1 with gamma secretase inhibitors (GSIs) sensitized GC-resistant T-ALL cell lines and primary samples to GC-induced apoptosis, supporting a role for GC plus GSIs in the treatment of GC-resistant T-ALLs. Here, we have used a Systems Biology approach to uncover additional pathways involved in the regulation of glucocorticoid receptor activity and glucocorticoid resistance in ALL. In this approach we used Master Regulator Inference analysis (MaRInA), a novel algorithm designed to identify critical regulators of complex biological traits, to analyze the gene expression profiles of pre-treatment T-ALL samples determined to be either sensitive (IC50<150μ g/ml) or resistant (IC50>150μ g/ml) to GC-induced apoptosis in vitro. This analysis identified a transcriptional module controlled by the AKT pathway as the most highly enriched gene set in the resistant samples, strongly suggesting a critical role for PI3K-AKT signaling in the regulation of glucocorticoid resistance in T-ALL. Notably, loss PTEN and constitutive activation of AKT are highly prevalent in T-ALL. Analysis of the effects of AKT in the transcriptional activity of the glucocorticoid receptor and in glucocorticoid receptor induced apoptosis revealed that constitutive activation of AKT results in impaired glucocorticoid receptor activity. Based on these results we hypothesize that AKT could have a direct inhibitory effect on the glucocorticoid receptor. Consistent with this hypothesis, mass spectrometry analysis demonstrated high levels of phosphorylation of the NR3C1 Ser134 in cells harbouring constitutively active AKT. Notably, this residue is within an AKT consensus sequence, XRXXS, and is highly conserved amongst species. Moreover, protein pull down and in vitro kinase assays demonstrated that AKT can directly interact with NR3C1 and mediates its phosphorylation on Ser134. Analysis of the biological relevance of this posttranslational modification showed that constitutively active AKT induces: (i) marked decrease in NR3C1 stability; (ii) retention of NR3C1 in the cytosol in the presence of dexamethasone and (iii) impaired glucocorticoid receptor autoupregulation; all of which can be blocked by the expression of a phosphorylation-deficient serine to alanine (S134A) NR3C1 mutant. Analysis of the effects of AKT activation on the interaction between NOTCH1 signaling and glucocorticoid induced apoptosis showed that AKT can effectively block the reversal of glucocorticoid resistance induced by inhibition of NOTCH1 signaling with GSIs in a Ser134 phosphorylation dependent manner. Finally, we demonstrate that pharmacologic inhibition of AKT can effectively reverse glucocorticoid resistance in T-ALL primary human samples and cell lines. Overall these results identify a direct interaction between the PI3K/AKT pathway and NR3C1 signaling and provide a strong rationale for the clinical testing the combination of AKT inhibitors and glucocorticoids in T-ALL. Disclosures: No relevant conflicts of interest to declare.

Design, Synthesis, Molecular Docking, and Anticancer Evaluation of Pyrazole Linked Pyrazoline Derivatives with Carbothioamide Tail as EGFR Kinase Inhibitors

2020 ◽  
Vol 21 (1) ◽  
pp. 42-60
Author(s):  
Farah Nawaz ◽  
Ozair Alam ◽  
Ahmad Perwez ◽  
Moshahid A. Rizvi ◽  
Mohd. Javed Naim ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
Cancer Cell Line ◽  
Cancer Cell Lines ◽  
Kinase Assay ◽  
Cervix Uteri ◽  
Egfr Kinase

Background: The Epidermal Growth Factor Receptor (known as EGFR) induces cell differentiation and proliferation upon activation through the binding of its ligands. Since EGFR is thought to be involved in the development of cancer, the identification of new target inhibitors is the most viable approach, which recently gained momentum as a potential anticancer therapy. Objective: To assess various pyrazole linked pyrazoline derivatives with carbothioamide for EGFR kinase inhibitory as well as anti-proliferative activity against human cancer cell lines viz. A549 (non-small cell lung tumor), MCF-7 (breast cancer cell line), SiHa (cancerous tissues of the cervix uteri), and HCT-116 (colon cancer cell line). Methods: In vitro EGFR kinase assay, in vitro MTT assay, Lactate dehydrogenase release, nuclear staining (DAPI), and flow cytometry cell analysis. Results: Compounds 6h and 6j inhibited EGFR kinase at concentrations of 1.66μM and 1.9μM, respectively. Furthermore, compounds 6h and 6j showed the most potent anti-proliferative results against the A549 KRAS mutation cell line (IC50 = 9.3 & 10.2μM). Through DAPI staining and phase contrast microscopy, it was established that compounds 6h and 6j also induced apoptotic activity in A549 cells. This activity was further confirmed by FACS using Annexin-V-FITC and Propidium Iodide (PI) labeling. Molecular docking studies performed on 6h and 6j suggested that the compounds can bind to the hinge region of ATP binding site of EGFR tyrosine kinase in a similar pose as that of the standard drug gefitinib. Conclusion: The potential anticancer activity of compounds 6h and 6j was confirmed and need further exploration in cancer cell lines of different tissue origin and signaling pathways, as well as in animal models of cancer development.

scholarly journals HERV-K Gag RNA and Protein Levels Are Elevated in Malignant Regions of the Prostate in Males with Prostate Cancer

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 449
Author(s):  
Simin D. Rezaei ◽  
Joshua A. Hayward ◽  
Sam Norden ◽  
John Pedersen ◽  
John Mills ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Lines ◽  
Endogenous Retrovirus ◽  
Human Endogenous Retrovirus ◽  
Normal Prostate ◽  
Tissue Samples ◽  
Gag Protein ◽  
Protein Levels ◽  
Prostate Epithelial Cells ◽  
Prostate Cancers

Heightened expression of human endogenous retrovirus (HERV) sequences has been associated with a range of malignancies, including prostate cancer, suggesting that they may serve as useful diagnostic or prognostic cancer biomarkers. We analysed the expression of HERV-K (Gag and Env/Np9 regions), HERV-E 4.1 (Pol and Env regions), HERV-H (Pol) and HERV-W (Gag) sequences in prostate cancer cells lines and normal prostate epithelial cells using qRT-PCR. HERV expression was also analysed in matched malignant and benign prostate tissue samples from men with prostate cancer (n = 27, median age 65.2 years (range 47–70)) and compared to prostate cancer-free male controls (n = 11). Prostate cancer epithelial cell lines exhibited a signature of HERV RNA overexpression, with all HERVs analysed, except HERV-E Pol, showing heightened expression in at least two, but more commonly all, cell lines analysed. Analysis of primary prostate material indicated increased expression of HERV-E Pol but decreased expression of HERV-E Env in both malignant and benign regions of the prostate in men with prostate cancer as compared to those without. Expression of HERV-K Gag was significantly higher in malignant regions of the prostate in men with prostate cancer as compared to matched benign regions and prostate cancer-free men (p < 0.001 for both), with 85.2% of prostate cancers donors showing malignancy-associated upregulation of HERV-K Gag RNA. HERV-K Gag protein was detected in 12/18 (66.7%) malignant tissues using immunohistochemistry, but only 1/18 (5.6%) benign tissue sections. Heightened expression of HERV-K Gag RNA and protein appears to be a sensitive and specific biomarker of prostate malignancy in this cohort of men with prostate carcinoma, supporting its potential utility as a non-invasive, adjunct clinical biomarker.

scholarly journals Inhibition of the Myocardin-Related Transcription Factor Pathway Increases Efficacy of Trametinib in NRAS-Mutant Melanoma Cell Lines

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2012
Author(s):  
Kathryn M. Appleton ◽  
Charuta C. Palsuledesai ◽  
Sean A. Misek ◽  
Maja Blake ◽  
Joseph Zagorski ◽  
...  
Keyword(s):  
Cell Lines ◽  
Melanoma Cell ◽  
Therapeutic Potential ◽  
Mapk Pathway ◽  
Mek Inhibitor ◽  
Intrinsic Resistance ◽  
Primary Resistance ◽  
Induced Apoptosis ◽  
Melanoma Cell Lines

The Ras/MEK/ERK pathway has been the primary focus of targeted therapies in melanoma; it is aberrantly activated in almost 80% of human cutaneous melanomas (≈50% BRAFV600 mutations and ≈30% NRAS mutations). While drugs targeting the MAPK pathway have yielded success in BRAFV600 mutant melanoma patients, such therapies have been ineffective in patients with NRAS mutant melanomas in part due to their cytostatic effects and primary resistance. Here, we demonstrate that increased Rho/MRTF-pathway activation correlates with high intrinsic resistance to the MEK inhibitor, trametinib, in a panel of NRAS mutant melanoma cell lines. A combination of trametinib with the Rho/MRTF-pathway inhibitor, CCG-222740, synergistically reduced cell viability in NRAS mutant melanoma cell lines in vitro. Furthermore, the combination of CCG-222740 with trametinib induced apoptosis and reduced clonogenicity in SK-Mel-147 cells, which are highly resistant to trametinib. These findings suggest a role of the Rho/MRTF-pathway in intrinsic trametinib resistance in a subset of NRAS mutant melanoma cell lines and highlight the therapeutic potential of concurrently targeting the Rho/MRTF-pathway and MEK in NRAS mutant melanomas.

Bortezomib blocks Bax degradation in malignant B cells during treatment with TRAIL

Blood ◽  
2008 ◽  
Vol 111 (5) ◽  
pp. 2797-2805 ◽  
Author(s):  
Feng-Ting Liu ◽  
Samir G. Agrawal ◽  
John G. Gribben ◽  
Hongtao Ye ◽  
Ming-Qing Du ◽  
...  
Keyword(s):  
B Cells ◽  
Cell Lines ◽  
Proteasome Inhibitor ◽  
Resistant Cell ◽  
Protein Levels ◽  
Bax Protein ◽  
Degradation Activity ◽  
Potent Drug ◽  
Induced Apoptosis

Proapoptotic Bcl-2 family member Bax is a crucial protein in the induction of apoptosis, and its activation is required for this process. Here we report that Bax is a short-lived protein in malignant B cells and Bax protein levels decreased rapidly when protein synthesis was blocked. Malignant B cells were relatively resistant to tumor necrosis factor–related apoptosis inducing ligand (TRAIL)–induced apoptosis, and this correlated with low basal Bax protein levels. Furthermore, during treatment with TRAIL, the resistant cell lines showed prominent Bax degradation activity. This degradation activity was localized to mitochondrial Bax and could be prevented by truncated Bid, a BH3-only protein; in contrast, cytosolic Bax was relatively stable. The proteasome inhibitor bortezomib is a potent drug in inducing apoptosis in vitro in malignant B-cell lines and primary chronic lymphocytic leukemic (CLL) cells. In CLL cells, bortezomib induced Bax accumulation, translocation to mitochondria, conformational change, and oligomerization. Accumulation and stabilization of Bax protein by bortezomib-sensitized malignant B cells to TRAIL-induced apoptosis. This study reveals that Bax instability confers resistance to TRAIL, which can be reversed by Bax stabilization with a proteasome inhibitor.

scholarly journals Activity of the Ste20-like kinase, SLK, is enhanced by homodimerization

2011 ◽  
Vol 301 (3) ◽  
pp. F554-F564 ◽  
Author(s):  
Sierra Delarosa ◽  
Julie Guillemette ◽  
Joan Papillon ◽  
Ying-Shan Han ◽  
Arnold S. Kristof ◽  
...  
Keyword(s):  
Catalytic Domain ◽  
Gel Filtration ◽  
Coiled Coil ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Luciferase Reporter ◽  
Fk506 Binding Protein ◽  
Induced Apoptosis ◽  
Injury And Repair

The expression and activation of the Ste20-like kinase, SLK, is increased during renal development and recovery from ischemic acute renal failure. SLK promotes apoptosis, and during renal injury and repair, transcriptional induction or posttranscriptional control of SLK may, therefore, regulate cell survival. SLK contains protein interaction (coiled-coil) domains, suggesting that posttranslational homodimerization may also modulate SLK activity. We therefore expressed coiled-coil regions in the C-terminal domain of SLK as fusion proteins and demonstrated their homodimerization. By gel-filtration chromatography, endogenous and heterologously expressed SLK were detected in a macromolecular protein complex. To test the role of homodimerization in kinase activation, we constructed a fusion protein consisting of the SLK catalytic domain (amino acids 1–373) and a modified FK506 binding protein, Fv (Fv-SLK 1–373). Addition of AP20187 (an analog of FK506) enhanced the homodimerization of Fv-SLK 1–373. In an in vitro kinase assay, the dimeric Fv-SLK 1–373 displayed greater kinase activity than the monomeric form. In cells expressing Fv-SLK 1–373, homodimerization increased activation-specific phosphorylation of the proapoptotic kinases, c-Jun N-terminal kinase and p38 kinase. Compared with the monomer, dimeric Fv-SLK 1–373 enhanced the activation of a Bax promoter-luciferase reporter. Finally, expression of Fv-SLK 1–373 induced apoptosis, and the effect was increased by homodimerization. Thus the activity, downstream signaling, and functional effects of SLK are enhanced by dimerization of the kinase domain.

Differential activation of ER stress and apoptosis in response to chronically elevated free fatty acids in pancreatic β-cells

2008 ◽  
Vol 294 (3) ◽  
pp. E540-E550 ◽  
Author(s):  
Elida Lai ◽  
George Bikopoulos ◽  
Michael B. Wheeler ◽  
Maria Rozakis-Adcock ◽  
Allen Volchuk
Keyword(s):  
Er Stress ◽  
Cell Lines ◽  
Cell Apoptosis ◽  
Human Islets ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Min6 Cells ◽  
Relative Contribution ◽  
Induced Apoptosis

Chronic exposure to elevated saturated free fatty acid (FFA) levels has been shown to induce endoplasmic reticulum (ER) stress that may contribute to promoting pancreatic β-cell apoptosis. Here, we compared the effects of FFAs on apoptosis and ER stress in human islets and two pancreatic β-cell lines, rat INS-1 and mouse MIN6 cells. Isolated human islets cultured in vitro underwent apoptosis, and markers of ER stress pathways were elevated by chronic palmitate exposure. Palmitate also induced apoptosis in MIN6 and INS-1 cells, although the former were more resistant to both apoptosis and ER stress. MIN6 cells were found to express significantly higher levels of ER chaperone proteins than INS-1 cells, which likely accounts for the ER stress resistance. We attempted to determine the relative contribution that ER stress plays in palmitate-induced β-cell apoptosis. Although overexpressing GRP78 in INS-1 cells partially reduced susceptibility to thapsigargin, this failed to reduce palmitate-induced ER stress or apoptosis. In INS-1 cells, palmitate induced apoptosis at concentrations that did not result in significant ER stress. Finally, MIN6 cells depleted of GRP78 were more susceptible to tunicamycin-induced apoptosis but not to palmitate-induced apoptosis compared with control cells. These results suggest that ER stress is likely not the main mechanism involved in palmitate-induced apoptosis in β-cell lines. Human islets and MIN6 cells were found to express high levels of stearoyl-CoA desaturase-1 compared with INS-1 cells, which may account for the decreased susceptibility of these cells to the cytotoxic effects of palmitate.

scholarly journals Mouse Receptor Interacting Protein 3 Does Not Contain a Caspase-Recruiting or a Death Domain but Induces Apoptosis and Activates NF-κB

1999 ◽  
Vol 19 (10) ◽  
pp. 6500-6508 ◽  
Author(s):  
Nanette J. Pazdernik ◽  
David B. Donner ◽  
Mark G. Goebl ◽  
Maureen A. Harrington
Keyword(s):  
Sequence Similarity ◽  
Kinase Domain ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Death Domain ◽  
Interacting Protein ◽  
C Terminus ◽  
Catalytically Active ◽  
Induced Apoptosis

ABSTRACT The death domain-containing receptor superfamily and their respective downstream mediators control whether or not cells initiate apoptosis or activate NF-κB, events critical for proper immune system function. A screen for upstream activators of NF-κB identified a novel serine-threonine kinase capable of activating NF-κB and inducing apoptosis. Based upon domain organization and sequence similarity, this novel kinase, named mRIP3 (mouse receptor interacting protein 3), appears to be a new RIP family member. RIP, RIP2, and mRIP3 contain an N-terminal kinase domain that share 30 to 40% homology. In contrast to the C-terminal death domain found in RIP or the C-terminal caspase-recruiting domain found in RIP2, the C-terminal tail of mRIP3 contains neither motif and is unique. Despite this feature, overexpression of the mRIP3 C terminus is sufficient to induce apoptosis, suggesting that mRIP3 uses a novel mechanism to induce death. mRIP3 also induced NF-κB activity which was inhibited by overexpression of either dominant-negative NIK or dominant-negative TRAF2. In vitro kinase assays demonstrate that mRIP3 is catalytically active and has autophosphorylation site(s) in the C-terminal domain, but the mRIP3 catalytic activity is not required for mRIP3 induced apoptosis and NF-κB activation. Unlike RIP and RIP2, mRIP3 mRNA is expressed in a subset of adult tissues and is thus likely to be a tissue-specific regulator of apoptosis and NF-κB activity. While the lack of a dominant-negative mutant precludes linking mRIP3 to a known upstream regulator, characterizing the expression pattern and the in vitro functions of mRIP3 provides insight into the mechanism(s) by which cells modulate the balance between survival and death in a cell-type-specific manner.

Synthesis of Some Novel Benzimidazole Derivatives as Anticancer Agent, and Evaluation for CDK2 Inhibition Activity

2021 ◽  
Vol 17 ◽  
Author(s):  
Rania Helmy Abd El-Hameed ◽  
Samar Said Fatahala ◽  
Amira Ibrahim Sayed
Keyword(s):  
Cell Lines ◽  
Docking Study ◽  
Binding Pocket ◽  
Kinase Assay ◽  
Benzimidazole Derivatives ◽  
Pharmacological Activities ◽  
Anticancer Compounds ◽  
Anti Cancer ◽  
Hct 116

Background: Thiobezimidazoles reveal various pharmacological activities due to similarities with many natural and synthetic molecules, they can easily interact with biomolecules of living systems. Objective: A series of substituted 2-thiobezimidazoles has been synthesized .Twelve final compounds were screened for in vitro anti-cancer activities against sixty different cell-lines. Methods: The spectral data of the synthesized compounds were characterized. Docking study for active anticancer compounds and CDK2/CyclinA2 Kinase assay against standard reference; Imatinib were performed. Results: Two compounds (3c&3l) from the examined series revealed effective antitumor activity in vitro against two-cancer cell lines (Colon Cancer (HCT-116) and Renal Cancer (TK-10). The docking study of synthesized molecules discovered a requisite binding pose in CDK-ATP binding pocket. 3c &3l were promoted in the CDK2/CyclinA2 Kinase assay against standard reference Imatinib. Conclusion: Against all tested compounds ; two compounds 3c &3l were found active against two types of cell-lines.

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