Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P05412 (c-Jun)
11,453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mitogen-activated protein kinases (MAPK) play a crucial role in signal transduction that regulates gene expression through transcriptional factor activity. The purpose of this study was to investigate the temporal expression and topographic distribution of the activated MAPK pathways including extracellular signal-regulated protein kinase (ERK), c-Jun NH(2)-terminal kinase (JNK), and p38 MAPK following traumatic brain injury (TBI) in the cortex of the rat brain. Adult male Sprague-Dawley rats (300-400 g) were subjected to lateral fluid percussion injury of moderate severity (3.5-4.0 atm) using the Dragonfly device model (no. HPD-1700). Phosphorylated-MAPK protein levels were quantified using Western blot analysis. Topographic distribution of immunoreactivity for phosphorylated-MAPK was examined using immunohistochemistry. Our findings showed that TBI significantly increased the phosphorylated-ERK (p-ERK) and -JNK (p-JNK) levels, but not the -p38 (p-p38) protein levels in the cortex surrounding the injury site. The immunoreactivity for p-ERK and p-JNK immediately after TBI were localized in neurons. The immunoreactivity for p-JNK was uniformly but only transiently induced and returned to control levels 1 h after TBI. The immunoreactivity for p-ERK was confirmed up until 30 min after TBI in the superficial neuronal layers. Double immunostaining using a glial-specific marker demonstrated that p-ERK was prominent in astrocytes 6 h after TBI. The current results suggest that the ERK and JNK pathways, but not the p38 MAPK pathways are involved in signal transduction in the cortex following TBI.
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PMID:Temporal and spatial profile of phosphorylated mitogen-activated protein kinase pathways after lateral fluid percussion injury in the cortex of the rat brain. 1254 59

Polyamine analogs have demonstrated considerable activity against many important solid tumor models including breast cancer. However, the precise mechanisms of antitumor activities of polyamine analogs are not entirely understood. The cytotoxicity of a newly developed polyamine analog compound, SL11144, against human breast cancer was assessed. Treatment of human breast cancer cell lines in culture with SL11144 decreased cell proliferation and induced programmed cell death in a time- and dose-dependent manner. SL11144 also profoundly inhibited the growth of MDA-MB-231 xenografts in host nude mice without overt toxic effects. Treatment of MDA-MB-435 cells with SL11144 led to the release of cytochrome c from mitochondria into cytosol, activation of caspase-3, and poly(ADP-ribose) polymerase cleavage. SL11144 decreased Bcl-2 and increased Bax protein levels in MDA-MB-231 cells. Furthermore, activator protein 1 transcriptional factor family member c-Jun was up-regulated by SL11144 in MDA-MB-435 and MDA-MB-231 cells, but not in MCF7 cells. In addition, significant inhibition of ornithine decarboxylase activity and a decrease in polyamine pools were demonstrated. These results demonstrate that the novel polyamine analog SL11144 has effective antineoplastic action against human breast cancer cells in vitro and in vivo and that multiple apoptotic mechanisms are associated with its cytotoxic effect in specific human breast cancer cell lines.
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PMID:A novel polyamine analog inhibits growth and induces apoptosis in human breast cancer cells. 1285 57

Mitogen-activated protein kinase (MAPK) cascades play essential roles in the transduction of extracellular signals to cytoplasmic and nuclear effectors. The MAPK kinase kinase MEKK2 is essential for activation of c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase 5 (ERK5). These pathways are important for expression of specific cytokine genes in mast cells following cross-linking of the high-affinity IgE receptor (FcepsilonRI). A consequence of ERK5 activation is activation of the transcriptional factor myocyte enhancing factor-2C (MEF2C), leading to increased c-Jun expression. We have investigated the role of MEF2C activation in mast cells and demonstrated that it requires sequential activation of the signaling cascade of MEKK2-MEK5-ERK5. Following phosphorylation of MEF2C, activated MEF2C regulates transcription of c-Jun but not TNF-alpha. Inhibition of ERK5, MEK5 activation or activation of MEKK2-deficient mast cells was associated with inhibition of MEF2C phosphorylation and a decrease in c-Jun expression. Thus, these data define an activation module, MEKK2-MEK5-ERK5-MEF2C in the transcriptional activation of c-Jun in mast cells following FcepsilonRI cross-linking. These results demonstrate the novel and important, MEKK2-dependent role of MEF2C in induction of c-Jun expression in mast cells activated through FcepsilonRI, a pathway distinct from that involving MEKK2-MEK5-ERK5 in the regulation of mast cell cytokine production.
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PMID:MEF2C regulates c-Jun but not TNF-alpha gene expression in stimulated mast cells. 1451 74

The molecular mechanism of hypoxia-induced apoptosis has not been clearly elucidated. In this study, we investigated the involvement of extracellular signal-regulated protein kinase (ERK 1/2) in hypoxia-induced apoptosis using cobalt chloride in HeLa human cervical cancer cells. The cobalt chloride was used for the induction of hypoxia, and its IC(50) was 471.4 microM. We demonstrated the DNA fragmentation after incubation with concentrations more than 50 microM cobalt chloride for 24 h, and also evidenced the morphological changes of the cells undergoing apoptosis with electron microscopy. Next, we examined the signaling pathway of cobalt chloride-induced apoptosis in HeLa cells. ERK1/2 activation occurred 6 and 9 h after treatment with 600 microM cobalt chloride. Meanwhile, the pretreatment of the MEK 1 inhibitor (PD98059) completely blocked the cobalt chloride-induced ERK 1/2 activation. At the same time, the activated ERK 1/2 translocated into the nucleus and phosphorylated its transcriptional factor, c-Jun. In addition, the pretreatment of PD98059 inhibited the cobalt chloride-induced DNA fragmentation and apoptotic cell death. These results suggest that cobalt chloride is able to induce apoptotic activity in HeLa cells, and its apoptotic mechanism may be associated with signal transduction via ERK 1/2.
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PMID:Cobalt chloride-induced apoptosis and extracellular signal-regulated protein kinase activation in human cervical cancer HeLa cells. 1453 30

Marek's disease virus (MDV) is an acute transforming alphaherpesvirus that causes T-cell lymphomas in chickens. We previously reported the identification of a putative oncogene, meq, that is encoded only by the oncogenic serotype of MDV. The gene product, Meq, is a latent protein that is consistently expressed in MDV-transformed lymphoblastoid cells and tumor cells. Meq has a bZIP (basic leucine zipper) structure resembling the family of Jun/Fos. The mechanism whereby Meq transforms T cells remains poorly understood. In this study, we explored the properties of Meq as a transcriptional factor. We analyzed Meq's dimerization partners and its target genes in MSB-1, an MDV-transformed T-cell line. By using in vitro assays, we first demonstrated Meq's potential to dimerize with a variety of bZIP proteins. We then identified c-Jun as the primary dimerization partner of Meq. Both are found to be colocalized in the nucleus and corecruited to promoters with AP-1 sequences. By using chromatin immunoprecipitation (ChIP), we scanned the entire MDV genome for Meq binding sites and found three regions that were enriched with Meq binding: the MDV lytic replication origin, the promoter for Meq, and the promoter for ICP4. Transactivation assays using the above promoters showed that Meq/Meq homodimers exhibited repression activity, whereas Meq/Jun heterodimers showed activation. Finally, we were able to show by ChIP that Meq is recruited to the interleukin-2 promoter in a region encompassing an AP-1 site. Thus, in addition to providing general knowledge about the transcriptional properties of Meq, our studies revealed for the first time the ability of Meq to interact with the latent MDV and host genomes. Our data suggest, therefore, a role for Meq in viral genome regulation during latency, in addition to its putative causal role in T-cell transformation.
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PMID:Characterization of the chromosomal binding sites and dimerization partners of the viral oncoprotein Meq in Marek's disease virus-transformed T cells. 1461 Feb 5

Several polyamine analogues have efficacy against a variety of epithelial tumor models including breast cancer. Recently, a novel class of polyamine analogues designated as oligoamines has been developed. Here, we demonstrate that several representative oligoamine compounds inhibit in vitro growth of human breast cancer MDA-MB-435 cells. The activator protein-1 (AP-1) transcriptional factor family members, c-Jun and c-Fos, are up-regulated by oligoamines in MDA-MB-435 cells, suggesting a possible AP-1-dependent induction of apoptosis. However, the use of a novel c-Jun NH(2)-terminal kinase (JNK) inhibitor, SP600125, suggests that inhibition of c-Jun activity sensitized tumor cells to oligoamine-induced cell death. To directly test this hypothesis, cells were stably transfected with the dominant-negative mutant c-Jun (TAM67), which lacks the NH(2)-terminal transactivation domain. Cells overexpressing TAM67 exhibit normal growth kinetics but demonstrate a significantly increased sensitivity to oligoamine cytotoxicity and attenuated colony formation after oligoamine treatment. Furthermore, oligoamine treatment leads to more profound caspase-3 activation and poly(ADP-ribose) polymerase cleavage in TAM67 transfectants, suggesting that c-Jun acts as an antiapoptosis factor in MDA-MB-435 cells in response to oligoamine treatment. These findings indicate that oligoamine-inducible AP-1 plays a prosurvival role in oligoamine-treated MDA-MB-435 cells and that JNK/AP-1 might be a potential target for enhancing the therapeutic efficacy of polyamine analogues in human breast cancer.
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PMID:Regulation of polyamine analogue cytotoxicity by c-Jun in human MDA-MB-435 cancer cells. 1498 64

Terminal deoxynucleotidyl transferase (TdT) is a template-independent DNA polymerase that catalyses the incorporation of deoxyribonucleotides into the 3'-hydroxyl end of DNA templates and is thought to increase junctional diversity of antigen receptor genes. TdT is expressed only on immature lymphocytes and acute lymphoblastic leukaemia cells and its transcriptional expression is tightly regulated. We had previously found that protein kinase C (PKC) activation down-regulates TdT expression. PKC-activation induces the synthesis of the Fos and Jun proteins, known as the major components of activation protein 1 (AP-1) transcriptional factor implicated in transcriptional control. Here we report the identification of several DNA-protein interactions within the TdT promoter region in non-TdT expressing human cells. Sequence analysis revealed the presence of a putative AP-1-like DNA-binding site, suggesting that AP-1 may play a relevant role in TdT transcriptional regulation. Using a different source of nuclear extracts and the AP-1-TdT motif as a probe we identified several DNA-protein retarded complexes in electrophoretic mobility shift assays. Super-band shifting analysis using an antibody against c-Jun protein confirmed that the main interaction is produced by a nuclear factor that belongs to the AP-1 family transcription factors. Our findings suggest that the TdT gene expression is down-regulated, at least in part, through AP-1-like transcription factors.
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PMID:Terminal deoxynucleotidyl transferase is down-regulated by AP-1-like regulatory elements in human lymphoid cells. 1502 5

Activating transcription factor (ATF)-2 is a member of the ATF/cAMP response element-binding protein family of transcription factors, and its trans-activating capacity is enhanced by stress-activated protein kinases such as c-Jun NH(2)-terminal kinase (JNK) and p38. However, little is known about the in vivo roles played by ATF-2. Here, we identified the Drosophila homologue of ATF-2 (dATF-2) consisting of 381 amino acids. In response to UV irradiation and osmotic stress, Drosophila p38 (dp38), but not JNK, phosphorylates dATF-2 and enhances dATF-2-dependent transcription. Consistent with this, injection of dATF-2 double-stranded RNA (dsRNA) into embryos did not induce the dorsal closure defects that are commonly observed in the Drosophila JNK mutant. Furthermore, expression of the dominant-negative dp38 enhanced the aberrant wing phenotype caused by expression of a dominant-negative dATF-2. Similar genetic interactions between dATF-2 and the dMEKK1-dp38 signaling pathway also were observed in the osmotic stress-induced lethality of embryos. Loss of dATF-2 in Drosophila S2 cells by using dsRNA abrogated the induction of 40% of the osmotic stress-induced genes, including multiple immune response-related genes. This indicates that dATF-2 is a major transcriptional factor in stress-induced transcription. Thus, dATF-2 is critical for the p38-mediated stress response.
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PMID:Drosophila activating transcription factor-2 is involved in stress response via activation by p38, but not c-Jun NH(2)-terminal kinase. 1578 64

Rosmarinic acid (RA) is a naturally occurring polyphenolic and is found in several herbs in the Lamiaceae family, such as, Perilla frutescens. ADR is a potent anti-tumor drug, but is unfortunately potently cardiotoxic. This study was undertaken to investigate the inhibitory effect of RA on ADR-induced apoptosis in H9c2 cardiac muscle cells at a mechanistic level. In vitro, ADR significantly decreased the viabilities of H9c2 cells, and this was accompanied by apoptotic features, such as a change in nuclear morphology and caspase protease activation. RA was found to markedly inhibit these apoptotic characteristics by reducing intracellular ROS generation and by recovering the mitochondria membrane potential (delta psi). In addition, RA reversed the downregulations of GSH, SOD and Bcl-2 by ADR. In the present study, ADR was found to activate c-Jun N-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK), transcriptional factor-activator-protein (AP)-1. We found that c-fos, Jun-B, Jun-D and p-c-Jun were super shifted by ADR, indicating that these proteins have an important role in the ADR-induced AP-1 activation. The inhibitions of JNK and ERK using appropriate inhibitors or dominant negative cell lines reduced ADR-induced apoptosis in H9c2 cardiac muscle cells. Taken together, these results suggest that RA can inhibit ADR-induced apoptosis in H9C2 cardiac muscle cells by inhibiting ROS generation and JNK and ERK activation. Thus, we propose that RA should be viewed as a potential chemotherapeutic that inhibits cardiotoxicity in ADR-exposed patients.
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PMID:Inhibitory effects of rosmarinic acid on adriamycin-induced apoptosis in H9c2 cardiac muscle cells by inhibiting reactive oxygen species and the activations of c-Jun N-terminal kinase and extracellular signal-regulated kinase. 1610 32

Cinnamaldehyde derivatives isolated from Cinnamomum cassia have been widely used for treating dyspepsia, gastritis, and inflammatory disease as well as cancer. To investigate the anti-tumor activities of several cinnamaldehyde derivatives, we compared the inhibitory effect of cinnamaldehyde derivatives on cell growth and AP-1 transcriptional activity in SW620 human colon cancer cells since AP-1 is a transcriptional factor implicated to control cancer cell growth. Among the derivatives, 2'-hydroxycinnamaldehyde (HCA) most significantly inhibited cancer cell growth and AP-1 transcriptional activity in a dose-dependent manner with an IC50 value of 12.5 and 9 microg/ml, respectively. In further studies on the mechanism, we found that consistent with the inhibitory effect on cell growth, HCA dose-dependently (0-20 microg/ml) inhibited DNA binding activity of AP-1 accompanied with down regulation of c-Jun and c-Fos expressions. HCA also induced apoptotic cell death as well as expression of the apoptosis-regulating gene caspase-3, but inhibited the anti-apoptosis regulating gene bcl-2 in a dose-dependent manner. These results suggested that HCA has the most potent inhibitory effect against human colon cancer cell growth, and AP-1 may be an important target of HCA.
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PMID:2-hydroxycinnamaldehyde inhibits SW620 colon cancer cell growth through AP-1 inactivation. 1751 May 24


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