scholarly journals Protein kinase C isozymes; predictors of progression free survival in NSCLC patients

2019 ◽  
Author(s):  
Ann Rita Halvorsen ◽  
Mads Haugland Haugen ◽  
Åsa Kristina Öjlert ◽  
Marius Lund-Iversen ◽  
Lars Jørgensen ◽  
...  

Abstract Background Protein expression is deregulated in cancer, and the proteomic changes observed in lung cancer may be a consequence of mutations in essential genes. The purpose of this study was to identify protein expression associated with prognosis in lung cancers stratified by smoking status, molecular subtypes, and EGFR-, TP53- and KRAS-mutations. Methods We performed profiling of 295 cancer-relevant phosphorylated and non-phosphorylated proteins, using reverse phase protein arrays. Biopsies from 80 patients with operable lung adenocarcinomas were analyzed for protein expression and association with progression free survival (PFS) were studied. Results Spearman rank correlation analysis identified 56 proteins with significant association to PFS (p<0.05). High expression of protein kinase C (PKC)-α and the phosporylated state of PKC-α, PKC-β and PKC-δ, showed the strongest positive correlation to PFS, especially in the wild type samples. This was confirmed in gene expression data from 186 samples. Based on protein expression, unsupervised hierarchical clustering separated the samples into four subclusters enriched with the molecular subtypes TRU, PI or PP (p=0.0001). Subcluster 2 contained a smaller cluster (2a) enriched with samples of the subtype PP, low expression of the PKC isozymes, and associated with poor PFS (p=0.003) compared to the other samples. Subcluster 2a revealed increased expression of neuroendocrine markers, supporting the aggressive behavior. Low expression of the PKC isozymes in the subtype PP and a reduced relapse free survival was confirmed with the TCGA LUAD samples. Conclusion This study identified different proteins associated with PFS depending on molecular subtype, smoking- and mutational-status, with PKC-α, PKC-β and PKC-δ showing the strongest correlation. Cluster analysis detected a subgroup of samples enriched for samples of the PP subtype and poor PFS, which may benefit from a more aggressive treatment regimen.

2020 ◽  
Vol 10 ◽  
Author(s):  
Ann Rita Halvorsen ◽  
Mads Haugland Haugen ◽  
Åsa Kristina Öjlert ◽  
Marius Lund-Iversen ◽  
Lars Jørgensen ◽  
...  

IntroductionProtein expression is deregulated in cancer, and the proteomic changes observed in lung cancer may be a consequence of mutations in essential genes. The purpose of this study was to identify protein expression associated with prognosis in lung cancers stratified by smoking status, molecular subtypes, and EGFR-, TP53-, and KRAS-mutations.MethodsWe performed profiling of 295 cancer-relevant phosphorylated and non-phosphorylated proteins, using reverse phase protein arrays. Biopsies from 80 patients with operable lung adenocarcinomas were analyzed for protein expression and association with relapse free survival (RFS) were studied.ResultsSpearman’s rank correlation analysis identified 46 proteins with significant association to RFS (p&lt;0.05). High expression of protein kinase C (PKC)-α and the phosporylated state of PKC-α, PKC-β, and PKC-δ, showed the strongest positive correlation to RFS, especially in the wild type samples. This was confirmed in gene expression data from 172 samples. Based on protein expression, unsupervised hierarchical clustering separated the samples into four subclusters enriched with the molecular subtypes terminal respiratory unit (TRU), proximal proliferative (PP), and proximal inflammatory (PI) (p=0.0001). Subcluster 2 contained a smaller cluster (2a) enriched with samples of the subtype PP, low expression of the PKC isozymes, and associated with poor RFS (p=0.003) compared to the other samples. Low expression of the PKC isozymes in the subtype PP and a reduced relapse free survival was confirmed with The Cancer Genome Atlas (TCGA) lung adenocarcinoma (LUAD) samples.ConclusionThis study identified different proteins associated with RFS depending on molecular subtype, smoking- and mutational-status, with PKC-α, PKC-β, and PKC-δ showing the strongest correlation.


Author(s):  
Ghanshyam N Pandey ◽  
Anuradha Sharma ◽  
Hooriyah S Rizavi ◽  
Xinguo Ren

Abstract Background Several lines of evidence suggest the abnormalities of protein kinase C (PKC) signaling system in mood disorders and suicide based primarily on the studies of PKC and its isozymes in the platelets and postmortem brain of depressed and suicidal subjects. In this study we examined the role of PKC isozymes in depression and suicide. Methods We determined the protein and mRNA expression of various PKC isozymes in the prefrontal cortical region [Brodmann area 9 (BA9)] in 24 normal control (NC) subjects, 24 depressed suicide (DS) subjects and 12 depressed non-suicide (DNS) subjects. The levels of mRNA in the prefrontal cortex (PFC) were determined by qRT-PCR and the protein expression was determined by Western blotting. Results We observed a significant decrease in mRNA expression of PKCα, PKCβI, PKCδ and PKCε and decreased protein expression either in the membrane or the cytosol fraction of PKC isozymes - PKCα, PKCβI, PKCβII and PKCδ in DS and DNS subjects compared with NC subjects. Conclusions The current study provides detailed evidence of specific dysregulation of certain PKC isozymes in the postmortem brain of DS and DNS subjects and further supports earlier evidence for the role of PKC in the platelets and brain of adult and teenage depressed and suicidal population. This comprehensive study may lead to further knowledge of the involvement of PKC in the pathophysiology of depression and suicide.


2021 ◽  
Vol 22 (11) ◽  
pp. 5527
Author(s):  
Mohammad Mojtaba Sadeghi ◽  
Mohamed F. Salama ◽  
Yusuf A. Hannun

Driver-directed therapeutics have revolutionized cancer treatment, presenting similar or better efficacy compared to traditional chemotherapy and substantially improving quality of life. Despite significant advances, targeted therapy is greatly limited by resistance acquisition, which emerges in nearly all patients receiving treatment. As a result, identifying the molecular modulators of resistance is of great interest. Recent work has implicated protein kinase C (PKC) isozymes as mediators of drug resistance in non-small cell lung cancer (NSCLC). Importantly, previous findings on PKC have implicated this family of enzymes in both tumor-promotive and tumor-suppressive biology in various tissues. Here, we review the biological role of PKC isozymes in NSCLC through extensive analysis of cell-line-based studies to better understand the rationale for PKC inhibition. PKC isoforms α, ε, η, ι, ζ upregulation has been reported in lung cancer, and overexpression correlates with worse prognosis in NSCLC patients. Most importantly, PKC isozymes have been established as mediators of resistance to tyrosine kinase inhibitors in NSCLC. Unfortunately, however, PKC-directed therapeutics have yielded unsatisfactory results, likely due to a lack of specific evaluation for PKC. To achieve satisfactory results in clinical trials, predictive biomarkers of PKC activity must be established and screened for prior to patient enrollment. Furthermore, tandem inhibition of PKC and molecular drivers may be a potential therapeutic strategy to prevent the emergence of resistance in NSCLC.


Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 381
Author(s):  
Noelia Geribaldi-Doldán ◽  
Irati Hervás-Corpión ◽  
Ricardo Gómez-Oliva ◽  
Samuel Domínguez-García ◽  
Félix A. Ruiz ◽  
...  

Glioblastoma (GBM) is the most frequent and aggressive primary brain tumor and is associated with a poor prognosis. Despite the use of combined treatment approaches, recurrence is almost inevitable and survival longer than 14 or 15 months after diagnosis is low. It is therefore necessary to identify new therapeutic targets to fight GBM progression and recurrence. Some publications have pointed out the role of glioma stem cells (GSCs) as the origin of GBM. These cells, with characteristics of neural stem cells (NSC) present in physiological neurogenic niches, have been proposed as being responsible for the high resistance of GBM to current treatments such as temozolomide (TMZ). The protein Kinase C (PKC) family members play an essential role in transducing signals related with cell cycle entrance, differentiation and apoptosis in NSC and participate in distinct signaling cascades that determine NSC and GSC dynamics. Thus, PKC could be a suitable druggable target to treat recurrent GBM. Clinical trials have tested the efficacy of PKCβ inhibitors, and preclinical studies have focused on other PKC isozymes. Here, we discuss the idea that other PKC isozymes may also be involved in GBM progression and that the development of a new generation of effective drugs should consider the balance between the activation of different PKC subtypes.


Cancers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1013
Author(s):  
Chara Papadaki ◽  
Stavroula Manolakou ◽  
Eleni Lagoudaki ◽  
Spyros Pontikakis ◽  
Despo Ierodiakonou ◽  
...  

CD44, a surface marker for cancer stem cells, interacts with PKM2, a key regulator of aerobic glycolysis, and enhances the glycolytic phenotype of cancer cells leading to antioxidant protection and macromolecules’ synthesis. To clarify the clinical importance of this “cross-talk” as a mechanism of drug resistance, we assessed the expression both of PKM2 and of CD44 in cancer cells of patients with epithelial ovarian cancer (EOC) treated with platinum-based treatment. One hundred and seventy-one patients with EOC were assessed for PKM2mRNA expression and PKM2 and CD44 proteins detection. Associations with progression-free survival (PFS) and overall survival (OS) were assessed with Kaplan–Meier and adjusted Cox regression models. PKM2mRNA and protein as well as CD44 protein were detectable in the majority of patients. Positive correlation between PKM2 and CD44 protein expression was observed (Spearman rho = 0.2, p = 0.015). When we used the median to group patients into high versus low expression, high PKM2mRNA and protein levels were significantly associated with lower progression-free survival (PFS; p = 0.003 and p = 0.002, respectively) and shorter overall survival (OS; p ≤ 0.001 and p = 0.001, respectively). However, high CD44 protein expression was significantly correlated only with shorter OS (p = 0.004). Moreover, patients with both high PKM2 and CD44 protein levels experienced shorter PFS and OS (p = 0.007 and p = 0.003, respectively) compared to patients with low expression of both proteins. Finally, higher PKM2mRNA and protein expression as well as CD44 protein expression (HR: 2.16; HR: 1.82; HR: 1.01, respectively) were independent prognostic factors for decreased median OS (mOS), whereas only PKM2 protein expression (HR: 1.95) was an independent prognostic factor for decreased median PFS (mPFS). In conclusion, PKM2 expression is a negative prognostic factor in EOC patients, but the interaction between CD44 and PKM2 that may be implicated in EOC platinum-resistance needs further investigation.


2000 ◽  
Vol 279 (3) ◽  
pp. L429-L438 ◽  
Author(s):  
Edward C. Dempsey ◽  
Alexandra C. Newton ◽  
Daria Mochly-Rosen ◽  
Alan P. Fields ◽  
Mary E. Reyland ◽  
...  

Individual protein kinase C (PKC) isozymes have been implicated in many cellular responses important in lung health and disease, including permeability, contraction, migration, hypertrophy, proliferation, apoptosis, and secretion. New ideas on mechanisms that regulate PKC activity, including the identification of a novel PKC kinase, 3-phosphoinositide-dependent kinase-1 (PDK-1), that regulates phosphorylation of PKC, have been advanced. The importance of targeted translocation of PKC and isozyme-specific binding proteins (like receptors for activated C-kinase and caveolins) is well established. Phosphorylation state and localization are now thought to be key determinants of isozyme activity and specificity. New concepts on the role of individual PKC isozymes in proliferation and apoptosis are emerging. Opposing roles for selected isozymes in the same cell system have been defined. Coupling to the Wnt signaling pathway has been described. Phenotypes for PKC knockout mice have recently been reported. More specific approaches for studying PKC isozymes and their role in cell responses have been developed. Strengths and weaknesses of different experimental strategies are reviewed. Future directions for investigation are identified.


2001 ◽  
Vol 281 (1) ◽  
pp. C17-C23 ◽  
Author(s):  
Sheng-Jun Pan ◽  
Mingyan Zhu ◽  
Mohan K. Raizada ◽  
Colin Sumners ◽  
Craig H. Gelband

It was previously determined that ANG II and phorbol esters inhibit Kv current in neurons cultured from newborn rat hypothalamus and brain stem in a protein kinase C (PKC)- and Ca2+-dependent manner. Here, we have further defined this signaling pathway by investigating the roles of “physiological” activators of PKC and different PKC isozymes. The cell-permeable PKC activators, diacylglycerol (DAG) analogs 1,2-dioctanoyl- sn-glycerol (1 μmol/l, n = 7) and 1-oleoyl-2-acetyl- sn-glycerol (1 μmol/l, n = 6), mimicked the effect of ANG II and inhibited Kv current. These effects were abolished by the PKC inhibitor chelerythrine (1 μmol/l, n = 5) or by chelation of internal Ca2+ ( n = 8). PKC antisense (AS) oligodeoxynucleotides (2 μmol/l) against Ca2+-dependent PKC isoforms were applied to the neurons to manipulate the endogenous levels of PKC. PKC-α-AS ( n = 4) treatment abolished the inhibitory effects of ANG II and 1-oleoyl-2-acetyl- sn-glycerol on Kv current, whereas PKC-β-AS ( n = 4) and PKC-γ-AS ( n = 4) did not. These results suggest that the angiotensin type 1 receptor-mediated effects of ANG II on neuronal Kv current involve activation of PKC-α.


2006 ◽  
Vol 291 (5) ◽  
pp. H2282-H2289 ◽  
Author(s):  
Hongying Zhang ◽  
DaLiao Xiao ◽  
Lawrence D. Longo ◽  
Lubo Zhang

Protein kinase C (PKC) plays an important role in the regulation of uterine artery contractility and its adaptation to pregnancy. The present study tested the hypothesis that PKC differentially regulates α1-adrenoceptor-mediated contractions of uterine arteries isolated from nonpregnant (NPUA) and near-term pregnant (PUA) sheep. Phenylephrine-induced contractions of NPUA and PUA sheep were determined in the absence or presence of the PKC activator phorbol 12,13-dibutyrate (PDBu). In NPUA sheep, PDBu produced a concentration-dependent potentiation of phenylephrine-induced contractions and shifted the dose-response curve to the left. In contrast, in PUA sheep, PDBu significantly inhibited phenylephrine-induced contractions and decreased their maximum response. Simultaneous measurement of contractions and intracellular free Ca2+ concentrations ([Ca2+]i) in the same tissues revealed that PDBu inhibited phenylephrine-induced [Ca2+]i and contractions in PUA sheep. In NPUA sheep, PDBu increased phenylephrine-induced contractions without changing [Ca2+]i. Western blot analysis showed six PKC isozymes, α, βI, βII, δ, ε, and ζ, in uterine arteries, among which βI, βII, and ζ isozymes were significantly increased in PUA sheep. In contrast, PKC-α was decreased in PUA sheep. In addition, analysis of subcellular distribution revealed a significant decrease in the particulate-to-cytosolic ratio of PKC-ε in PUA compared with that in NPUA sheep. The results suggest that pregnancy induces a reversal of PKC regulatory role on α1-adrenoceptor-mediated contractions from a potentiation in NPUA sheep to an inhibition in PUA sheep. The differential expression of PKC isozymes and their subcellular distribution in uterine arteries appears to play an important role in the regulation of Ca2+ mobilization and Ca2+ sensitivity in α1-adrenoceptor-mediated contractions and their adaptation to pregnancy.


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