Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We describe the application of two different fluorescence-based techniques (ddNTP primer extension and single-strand conformation polymorphism (SSCP)) to the detection of single nucleotide polymorphisms (SNPs) by capillary electrophoresis. The ddNTP primer extension technique is based on the extension, in the presence of fluorescence-labeled dideoxy nucleotides (ddNTP, terminators), of an unlabeled oligonucleotide primer that binds to the complementary template immediately adjacent to the mutant nucleotide position. Given that there are no unlabeled dNTPs, a single ddNTP is added to its 3' end, resulting in a fluorescence-labeled primer extension product which is readily separated by capillary electrophoresis. On the other hand, the non-radioisotopic version of SSCP established in this study uses fluorescent dye to label the PCR products, which are also analyzed by capillary electrophoresis. These procedures were used to identify a well-defined SNP in exon 7 of the human p53 gene in DNA samples isolated from two human cell lines (CEM and THP-1 cells). The results revealed a heterozygous single-base transition (G to A) at nucleotide position 14071 in CEM cells, proving that both fluorescence-based ddNTP primer extension and SSCP are rapid, simple, robust, specific and with no ambiguity in interpretation for the detection of well-defined SNPs.
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PMID:Rapid identification of single nucleotide polymorphisms by fluorescence-based capillary electrophoresis. 1496 15

Human monocytic THP-1 cells can be induced to differentiate to macrophages when treated with phorbol 12-myristate 13-acetate (PMA). It is understood that before initiating cell differentiation, PMA treatment must first induce an inhibition of cell growth. Since the initial biochemical and molecular events that are associated with this growth inhibition have not been characterized, the present study was carried out to elucidate the molecular mechanisms associated with the PMA-induced growth arrest of THP-1 cells. Our results indicate that PMA inhibits THP-1 cells at G1-phase of the cell cycle, via a complex mechanism associated with the modulation of the expression of several cell cycle regulators, initiated by the cellular generation of reactive oxygen species (ROS). Both p21WAF1/CIP1 mRNA and protein were upregulated 24 h post PMA treatment as demonstrated by ribonuclease protection assay and Western blotting, respectively. Because these cells lack functional p53, this effect was independent of p53 activity. Electrophoretic mobility shift assay showed that the PMA-induced activation of the p21WAF1/CIP1 promoter was driven by the specific protein 1 (Sp1) transcription factor through Sp1-binding sites. Additionally, our study demonstrates that PMA-induces the upregulation of p21 through a protein kinase C (PKC)-mediated ROS-dependent signaling mechanism involving MAP kinase activation.
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PMID:Signal transduction of phorbol 12-myristate 13-acetate (PMA)-induced growth inhibition of human monocytic leukemia THP-1 cells is reactive oxygen dependent. 1597 37

The aim of this study was to verify the hypothesis that beta-carotene may prevent 7-ketocholesterol (7-KC)-induced apoptosis in human macrophages. Therefore, THP-1 macrophages were exposed to 7-KC (5-50 microM) alone and in combination with beta-carotene (0.25-1 microM). 7-KC inhibited the growth of macrophages in a dose- and a time-dependent manner by inducing an arrest of cell cycle progression in the G0/G1 phase and apoptosis. Concomitantly, p53, p21, and Bax expressions were increased by 7-KC, whereas the levels of AKT, Bcl-2, and Bcl-xL were decreased. beta-Carotene prevented the growth-inhibitory effects of 7-KC in a dose- and time-dependent manner as well as the effects of 7-KC on the expression of cell cycle- and apoptosis-related proteins. 7-KC also enhanced reactive oxygen species (ROS) production through an increased expression of NAD(P)H oxidase (NOX-4). The effects of 7-KC were counteracted by the addition of the NAD(P)H oxidase inhibitor DPI or by cotransfection of siNOX-4 mRNA. beta-Carotene prevented 7-KC-induced increase in ROS production and in NOX-4 expression, as well as the phosphorylation of p38, JNK, and ERK1/2 induced by 7-KC. These data suggest a possible antiatherogenic role of beta-carotene through the prevention of 7-KC toxicity in human macrophages.
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PMID:Redox regulation of 7-ketocholesterol-induced apoptosis by beta-carotene in human macrophages. 2537 21

Pigment epithelial-derived factor (PEDF) is a potent anti-angiogenic factor, partially through the induction of endothelial cell apoptosis. Here we report that PEDF can also induce the apoptosis of human THP-1 monocytic leukemia cell line-derived macrophage cells (THP-1 macrophages) and peroxisome proliferator-activated receptor gamma (PPARgamma), a pleiotropic transcriptional factor is involved in the signaling. TUNEL and propidium iodide permeability assays demonstrated that PEDF dose- and time-dependently induces both apoptosis and necrosis of THP-1 macrophages while inducing the cleavages of procaspase-9, -3, the release of cytochrome c and the overexpression of p53. All these PEDF effects can be attenuated by either PPARgamma inhibitor GW9662 or PPARgamma small interfering RNA. The effects of PEDF can be reproduced by transient expression of PPARgamma by a PPARgamma-expression plasmid transfection. PEDF increased the expression and transcriptional activity of PPARgamma in THP-1 macrophages. In addition, PEDF also induced apoptosis in primary human monocyte-derived macrophages (MDMs) while inducing the expression of PPARgamma. Our observations indicate that PEDF induces macrophage apoptosis and necrosis through the signaling of PPARgamma. This suggests a novel mechanism through which PEDF can modulate inflammation.
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PMID:Pigment epithelium-derived factor induces THP-1 macrophage apoptosis and necrosis by the induction of the peroxisome proliferator-activated receptor gamma. 1787 Jan 67

In THP-1 monocytes, cellular proteasome inhibition by ritonavir or ALLN is associated with increased production of oxidative stress. Both compounds produced comparable amounts of oxidative stress; however, normalization by alpha-tocopherol occurred solely after inhibition by ritonavir, and not by ALLN. Similar to that, alpha-tocopherol could normalize the reduced formation of 3-nitrotyrosine-modified proteins only after ritonavir treatment. In the absence of any proteasome inhibitor, intrinsic cellular proteasome activity was not modulated by alpha-, beta-, and gamma-tocopherols; however, delta-tocopherol, alpha-tocotrienol, and alpha-tocopheryl phosphate could significantly inhibit cellular proteasome activity and increased the level of p27(Kip1) and p53. Since oxidative stress was reduced by alpha-tocopherol only after proteasome inhibition by ritonavir and not by ALLN, it is concluded that, in this experimental system, alpha-tocopherol does not act as an antioxidant but interferes with the inhibitory effect of ritonavir.
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PMID:Modulation of proteasome activity by vitamin E in THP-1 monocytes. 1808 77

Three new triterpene oligoglycosides, okhotosides B 1 ( 1), B 2 ( 2), and B 3 ( 3), have been isolated from the sea cucumber Cucumaria okhotensis along with the known compounds frondoside A ( 4), frondoside A 1, cucumarioside A 2-5, and koreoside A. The structures of 1- 3 were elucidated on the basis of their spectroscopic data (2D NMR and MS). Compounds 1- 3 were moderately toxic against HeLa tumor cells. Frondoside A ( 4) showed more potent cytotoxicity against THP-1 and HeLa tumor cell lines (with IC 50 values of 4.5 and 2.1 microg/mL, respectively) and decreased both the AP-1-dependent trascriptional activities induced by UVB, EGF, or TPA in JB6-LucAP-1 cells and the EGF-induced NF-kappaB-dependent transcriptional activity in JB6-LucNF-kB cells at doses of about 1 microg/mL. At the same doses, it increased the p53-dependent transcriptional activity in nonactivated JB6-Lucp53 cells and inhibited the colony formation of JB6 P (+) Cl 41 cells activated with EGF (INCC 50 = 0.8 microg/mL).
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PMID:Constituents of the sea cucumber Cucumaria okhotensis. Structures of okhotosides B1-B3 and cytotoxic activities of some glycosides from this species. 1828 10

We developed a novel derivatization reagent, (2R)-2,5-dioxopyrrolidin-1-yl-2,5,7,8-tetramethyl-6-(tetrahydro-2H-pyran-2-yloxy)chroman-2-carboxylate (NPCA), for electrochemical (EC) detection in HPLC. NPCA was synthesized from (R)-(+)-6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (alpha-CA), which exhibits intense EC response. NPCA successfully yielded alpha-CA derivatives of primary amines by a two-step derivatization procedure. Following pre-column derivatization with NPCA, a simultaneous determination of alpha-CA derivatives of neuroactive monoamines [dopamine (DA), epinephrine, and 5-hydroxytryptamine (5-HT)], their monoamine oxidase metabolites (3,4-dihydroxyphenylacetic acid, homovanillic acid, and 5-hydroxyindole-3-acetic acid) and their catechol-O-methyltransferase metabolites [3-methoxytyramine (3-MT) and normetanephrine (NMN)] was completely achieved using our HPLC-EC method. Using an HPLC equipped with coulometric electrode-array detection system, the resultant alpha-CA derivatives of NMN, 5-HT, DA and 3-MT showed intense EC responses, that were approximately 1.3, 1.4, 1.1 and 1.4-fold higher than the corresponding native forms, respectively. The detection limits were in the range of approximately 16-60 fmol on column (signal-to-noise ratio 3). The proposed HPLC method was applied to determine 5-HIAA, HVA, alpha-CA-5-HT and alpha-CA-DA in rat urine. As a consequence, these analytes were successfully determined with satisfactory precisions.
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PMID:Development of a 6-hydroxychroman-based derivatization reagent: application to the analysis of 5-hydroxytryptamine and catecholamines by using high-performance liquid chromatography with electrochemical detection. 1927 58

(4-(Tetrahydro-2H-pyran-2-yloxy)R1)R2-diamminedichloroplatinum(II) complexes (1-12) consisting of CDDP linked to THP via aliphatic CH2-spacers were tested in two TGCT cell lines. The most promising compound, 2-(4-(tetrahydro-2H-pyran-2-yloxy)-undecyl)-propane-1,3-diamminedichloroplatinum(II) (12), completely overcame CDDP resistance of 1411HP cells, correlating with increased and accelerated cellular platinum uptake and much faster initiation of apoptotic cell kill. At equitoxic IC90 concentrations, 12 induced accelerated DNA fragmentation and caspase -3 and PARP cleavages. In contrast, DNA platination rate was much lower as compared to CDDP and no upregulation of p53 as well as no initiation of cell cycle arrest were observed. Apoptosis induction by 12 could not be inhibited by pretreatment with caspase-specific inhibitor Z-VAD-Fmk and was accompanied by strong calcium release and generation of reactive oxygen species. To summarize, 12 overcomes CDDP resistance and induces programmed cell death with molecular features different from CDDP, suggesting that both drugs induce apoptosis through different initial pathways.
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PMID:2-(4-(Tetrahydro-2H-pyran-2-yloxy)-undecyl)-propane-1,3-diamminedichloroplatinum(II): a novel platinum compound that overcomes cisplatin resistance and induces apoptosis by mechanisms different from that of cisplatin. 1869 54

Nitric oxide (NO) is a reactive secondary mediator, which has been found to participate in cell cycle regulation and apoptosis in myeloid macrophages, the key effectors of inflammatory and innate immune responses. However, the molecular mechanisms of nitric oxide-induced death of myeloid macrophages are not well understood. In this study we have found that NO derived from S-nitrosoglutathione (GSNO) activates ASK1 in THP-1 human myeloid macrophages in a concentration and time-dependent manner. It also induces accumulation of HIF-1alpha protein in a concentration-dependent manner, which peaks at 4 h of exposure to 1 mM GSNO. GSNO does not affect the level of HIF-1alpha mRNA as detected by the RT-PCR. In addition, GSNO was found to induce accumulation of p53 in normal but not HIF-1alpha knockdown THP-1 cells, where expression of this protein was silenced by specific siRNA. It has also been found that GSNO-mediated accumulation of p53 depends on activation of ASK1 since no GSNO-induced p53 stabilisation was observed in THP-1 cells transfected with dominant-negative form of this kinase. However, in both HIF-1alpha knockdown THP-1 cells and those transfected with the dominant-negative form of ASK1, GSNO was able to induce cell death as detected by the MTS cell viability assay leading to an increase in release of LDH.
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PMID:Apoptosis signal-regulating kinase 1 (ASK1) and HIF-1alpha protein are essential factors for nitric oxide-dependent accumulation of p53 in THP-1 human myeloid macrophages. 1884 76

To potentiate the response of acute myelogenous leukemia (AML) cells to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) cytotoxicity, we have examined the efficacy of a combination with perifosine, a novel phosphatidylinositol-3-kinase (PI3K)/Akt signaling inhibitor. The rationale for using such a combination is that perifosine was recently described to increase TRAIL-R2 receptor expression and decrease the cellular FLICE-inhibitory protein (cFLIP) in human lung cancer cell lines. Perifosine and TRAIL both induced cell death by apoptosis in the THP-1 AML cell line, which is characterized by constitutive PI3K/Akt activation, but lacks functional p53. Perifosine, at concentrations below IC(50), dephosphorylated Akt and increased TRAIL-R2 levels, as shown by Western blot, reverse transcription-PCR, and flow cytometric analysis. Perifosine also decreased the long isoform of cFLIP (cFLIP-L) and the X-linked inhibitor of apoptosis protein (XIAP) expression. Perifosine and TRAIL synergized to activate caspase-8 and induce apoptosis, which was blocked by a caspase-8-selective inhibitor. Up-regulation of TRAIL-R2 expression was dependent on a protein kinase Calpha/c-Jun-NH(2)-kinase 2/c-Jun signaling pathway activated by perifosine through reactive oxygen species production. Perifosine also synergized with TRAIL in primary AML cells displaying constitutive activation of the Akt pathway by inducing apoptosis, Akt dephosphorylation, TRAIL-R2 up-regulation, cFLIP-L and XIAP down-regulation, and c-Jun phosphorylation. The combined treatment negatively affected the clonogenic activity of CD34(+) cells from patients with AML. In contrast, CD34(+) cells from healthy donors were resistant to perifosine and TRAIL treatment. Our findings suggest that the combination of perifosine and TRAIL might offer a novel therapeutic strategy for AML.
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PMID:Synergistic proapoptotic activity of recombinant TRAIL plus the Akt inhibitor Perifosine in acute myelogenous leukemia cells. 1901 Sep 14


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