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)

B-chronic lymphocytic leukemia (B-CLL) is an indolent lymphoid malignancy with variable prognosis. Adverse prognostic factors comprise treatment resistance, cytogenetics (11q- and 17p-), the presence of unmutated Ig genes, and the more comprehensive activation marker Zap 70. In contrast to diminished sensitivity to chemotherapy, Zap 70+ B-CLL cells retain their responsiveness to manipulation of signal transduction and monoclonals. Xanthohumol (XA) has recently been documented to have an impact on breast cancer cell growth and invasiveness in vitro. Based on these observations, lymphocytes from patients with B-CLL were cultured in the presence of XA in vitro. XA induced a dose-dependent killing of B-CLL cells at an LD(50) ((24 h)) of 24.4 +/- 6.6 microM, independent of known adverse prognostic factors including functional loss of p53. Cell death was associated with poly (ADP)-ribose polymerase cleavage and annexin V positivity, suggestive of an apoptotic mechanism. Surprisingly, p 70(S 6 K) phosphorylation was stimulated upon XA treatment. In conclusion, XA has an antitumor activity on B-CLL cells in vitro. The molecular mechanisms behind this pro-apoptotic effect deserve further investigation.
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PMID:Xanthohumol kills B-chronic lymphocytic leukemia cells by an apoptotic mechanism. 1614 30

Hexavalent chromium (Cr[VI]) is classified by the International Agency for Research on Cancer as a group I carcinogen. Although the U.S. Occupational Safety and Health Administration was obliged to reduce the permissible exposure limit (PEL), it was reported that U.S. workers continue to be exposed to dangerously high Cr(VI) levels. In this study, we examined the role of p53 and target genes in a bronchoalveolar carcinoma isogenic cell line system and in primary human bronchial epithelial cells. p53-Negative parental H358 cell line, the same line in which the wild-type p53 expression vector (pC53-SN3) was introduced, and cells obtained from biopsies of human bronchus were exposed to chromate. Induction of DNA strand breaks were evaluated by alkaline elution assay, and apoptosis was analyzed by gel ladder, annexin V-PI staining, and ELISA, whereas p53 and target genes were evaluated by Western blots. Although Cr(VI) induced DNA strand breaks in both H358 cell clones, apoptosis was present only in the p53-transfected cells (H358p53(+/+)). In these cells, Cr(VI)-induced apoptosis is mediated by p53 upregulation of p53-upregulated modulator of apoptosis (PUMA), BAX translocation to mitochondria, cytochrome c release, and caspase-3 activation. In primary human bronchial epithelial cells expressing functional p53, Cr(VI) induced expression of PUMA and Noxa, which promote apoptosis through BAX. This result establishes p53 as the "necessary" player in Cr(VI)-induced apoptosis. To the best of our knowledge, this is the first report indicating strict correlation of Cr(VI) apoptosis to PUMA induction on primary human bronchoalveolar cells in short-term cultures.
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PMID:Molecular mechanisms of hexavalent chromium-induced apoptosis in human bronchoalveolar cells. 1616 40

Only a few approaches are available to address the mechanisms of cell death in vivo which are induced by anticancer treatment in patients with malignancies. In this study in vitro chemosensitivity testing of primary peripheral blood leukemic cells of five patients suffering from different leukemic non-Hodgkin's lymphomas was combined with the analysis of the in vivo rate of apoptosis by flow-cytometry (Annexin V and depolarisation of mitochondrial membrane potential (MMP) by JC-1). Furthermore, changes in expression patterns of apoptosis related proteins during chemotherapeutic treatment were detected by Western Blot. Gene expression profiling (HG-U133A, Affymetrix, Santa Clara, CA) was employed to identify common marker genes of in vivo drug response. In vitro chemosensitivity was tested using the cytotoxic agents which the patients were scheduled to receive and was strongly correlated with effective reduction of leukemic lymphoma cells in patients resulting in complete remissions in all five cases. Due to the rapid clearance of apoptotic tumor cells in vivo neither the analysis of the in vivo rate of apoptosis and depolarisation of MMP nor the assessment of expression of regulators of apoptosis showed concordant results concerning the drug response. However, assessment of gene expression during therapy could identify a set of 30 genes to significantly discriminate between samples from patients before treatment compared to samples from the same patients after receiving cytotoxic therapy. Among these 30 genes we found a high proportion of genes associated with apoptotic cell death, cell proliferation and cell cycle signalling including complement lysis inhibitor (clusterin/CLU), beta-catenin interacting protein (ICAT), peroxisome proliferator activated receptor alpha (PPARalpha), TNF alpha converting enzyme (ADAM17/TACE), homeo box A3 (HOX1), inositol polyphosphatase 5-phosphatase type IV (PPI5PIV) and inhibitor of p53 induced apoptosis alpha (IPIA-Alpha/NM23-H6). These results indicate that in vitro chemosensitivity testing and gene expression profiling can successfully be utilised to analyse in vivo drug response in patients with leukemic NHL's and can be used to explore new pathway models of drug-induced cell death in vivo which are independent of different lymphoma subtypes and different treatment regimens.
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PMID:In vivo drug-response in patients with leukemic non-Hodgkin's lymphomas is associated with in vitro chemosensitivity and gene expression profiling. 1621 48

The Escherichia coli verotoxin 1 (VT1) inhibits protein synthesis, cell proliferation, and damages endothelial cell in the hemolytic uremic syndrome. VT1 can specifically bind and act on endothelial cells as well as on many tumor cells because these cells express its high affinity receptor, globotriaosylceramide. This indicates that VT1 may have both antiangiogenic and antineoplastic activities. We investigated this potential of VT1 by incubating several colon cancer cell lines with VT1 for different time periods and found that HCT116 cells were especially sensitive to VT1. A combination of morphological studies, flow cytometry, DNA laddering and annexin V staining confirmed that VT1 irreversibly arrests these cells in S phase within 24 h and prolonged incubation triggers DNA fragmentation. Concomitant to the activation of the S phase checkpoint, increased levels of mRNA and proteins of growth arrest and DNA damage-inducible gene family that include GADD34, GADD45alpha, and GADD45beta was observed. Interestingly, no significant changes in expression of key cell cycle related proteins such as cdk2, cdk4, p21, p27, and p53 was found during the S phase arrest and apoptosis. We therefore suggest that GADD proteins might play an important role in VT1 induced S phase arrest and programmed cell death in HCT116 cells.
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PMID:Escherichia coli verotoxin 1 mediates apoptosis in human HCT116 colon cancer cells by inducing overexpression of the GADD family of genes and S phase arrest. 1629 16

Ellipticine (5,11-dimethyl-6H-pyrido[4,3-b]carbazole), one of the simplest naturally occurring alkaloids, was isolated from the leaves of the evergreen tree Ochrosia elliptica Labill (Apocynaceae). Here, we reported that ellipticine inhibited the cell growth of human hepatocellular carcinoma cell line HepG2 and provided molecular understanding of this effect. The XTT assay results showed that ellipticine decreased the cell viability of HepG2 cells in a dose- and time-dependent manner, and the IC50 value was 4.1 microM. Furthermore, apoptosis induction by ellipticine in HepG2 cells was verified by the appearance of DNA fragmentation and annexin V-FITC/propidium iodide (PI) staining assay. Ellipticine treatment was found to result in the upregulation of p53, Fas/APO-1 receptor and Fas ligand. Besides, ellipticine also initiated mitochondrial apoptotic pathway through regulation of Bcl-2 family proteins expression, alteration of mitochondrial membrane potential (DeltaPsim), and activation of caspase-9 and caspase-3. Taken together, ellipticine decreased the cell growth and induced apoptosis in HepG2 cell.
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PMID:Ellipticine induces apoptosis through p53-dependent pathway in human hepatocellular carcinoma HepG2 cells. 1633 42

Sirtuins are a family of phylogenetically conserved nicotinamide adenine dinucleotide-dependent deacetylases that have a firmly established role in aging. Using a simple Saccharomyces cerevisiae yeast heterochromatic derepression assay, we tested a number of environmental chemicals to address the possibility that humans are exposed to sirtuin inhibitors. Here we show that dihydrocoumarin (DHC), a compound found in Melilotus officinalis (sweet clover) that is commonly added to food and cosmetics, disrupted heterochromatic silencing and inhibited yeast Sir2p as well as human SIRT1 deacetylase activity. DHC exposure in the human TK6 lymphoblastoid cell line also caused concentration-dependent increases in p53 acetylation and cytotoxicity. Flow cytometric analysis to detect annexin V binding to phosphatidylserine demonstrated that DHC increased apoptosis more than 3-fold over controls. Thus, DHC inhibits both yeast Sir2p and human SIRT1 deacetylases and increases p53 acetylation and apoptosis, a phenotype associated with senescence and aging. These findings demonstrate that humans are potentially exposed to epigenetic toxicants that inhibit sirtuin deacetylases.
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PMID:The flavoring agent dihydrocoumarin reverses epigenetic silencing and inhibits sirtuin deacetylases. 1636 78

In order to study the potential effects of exogenous WT1 gene isoform on apoptosis in leukemia cell line NB4 and its possible molecular mechanisms, the eukaryotic expression recombinant vector (pCB6(+)/WTA) containing full-length human WT1 isoform (WTA: -17aa/-KTS) cDNA and the vacant vector-alone were introduced into the leukemia cell line NB4 respectively by electroporation. The WTA mRNA and protein in cells were detected by RT-PCR and Western blot. Binding of Annexin V were tested by flow cytometry and agarose gel electrophoresis to verify whether exogenous WTA could induce apoptosis of NB4 cells. Expressions of p21, p53, bcl-2, bcl-XL and c-myc genes were determined by semi-quantitative RT-PCR after introducing recombinant vectors into the NB4 cells. The results showed that in exposure to As(2)O(3) at 0.8 micromol/L for 48 hours, the NB4/WTA cells exhibited the morphological hallmarks of apoptosis, the marked DNA ladder shown by gel electrophoresis, and the enhanced apoptosis rate marked by Annexin V. RT-PCR showed an increase in p21 and c-myc genes expression, a decrease in bcl-2 and a relative constant expression of p53, bcl-XL in NB4/WTA cells. It is concluded that the introduction and expression of exogenous WTA gene can lead to apoptosis of NB4/WTA cells by down-regulating the Bcl-2 gene expression and up-regulating the p21 and c-myc genes expression.
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PMID:[Experimental study on apoptosis of leukemia cell line NB4 transfected with WT1 gene]. 1640 65

The effects of a novel nutrient formulation Epican Forte (EF) were evaluated on proliferation and induction of apoptosis using non-cytotoxic concentrations against HTLV-1 positive (HuT-102 & C91-PL) and negative (CEM & Jurkat) cells. EF showed anti-proliferative effect as determined by MTT assay and TGF mRNA protein expression using RT-PCR. EF resulted in the down-regulation of TGF-alpha and an up-regulation in TGF-beta2. EF caused a significant increase in apoptotic cells in the preG1 phase. These results were confirmed using Cell Death ELISA and Annexin V-FITC. Induction of apoptosis was caused by an up-regulation of p53, p21 and Bax protein levels and a down-regulation of Bcl-2alpha protein expression level.
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PMID:Apoptosis induction by Epican Forte in HTLV-1 positive and negative malignant T-cells. 1642 25

We have shown that a COOH-terminal peptide of p53 (amino acids 361-382, p53p), linked to the truncated homeobox domain of Antennapedia (Ant) as a carrier for transduction, induced rapid apoptosis in human premalignant and malignant cell lines. Here, we report that human and rat glioma lines containing endogenous mutant p53 or wild-type (WT) p53 were induced into apoptosis by exposure to this peptide called p53p-Ant. The peptide was comparatively nontoxic to proliferating nonmalignant human and rat glial cell lines containing WT p53 and proliferating normal human peripheral marrow blood stem cells. Degree of sensitivity to the peptide correlated directly with the level of endogenous p53 expression and mutant p53 conformation. Apoptosis induction by p53p-Ant was quantitated by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay and Annexin V staining in human glioma cells in vitro and in a syngeneic orthotopic 9L glioma rat model using convection-enhanced delivery in vivo. The mechanism of cell death by this peptide was solely through the Fas extrinsic apoptotic pathway. p53p-Ant induced a 3-fold increase in extracellular membrane Fas expression in glioma cells but no significant increase in nonmalignant glial cells. These data suggest that p53 function for inducing Fas-mediated apoptosis in gliomas, which express sufficient quantities of endogenous mutant or WT p53, may be restored or activated, respectively, by a cell-permeable peptide derived from the p53 COOH-terminal regulatory domain (p53p-Ant). p53p-Ant may serve as a prototypic model for the development of new anticancer agents with unique selectivity for glioma cancer cells and it can be successfully delivered in vivo into a brain tumor by a convection-enhanced delivery system, which circumvents the blood-brain barrier.
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PMID:Restoration of p53 function for selective Fas-mediated apoptosis in human and rat glioma cells in vitro and in vivo by a p53 COOH-terminal peptide. 1643 59

The mechanism of toxicity p-phenylenediamine (p-PD), a component of human permanent hair dye and a suspected carcinogen, on the growth of Mardin-Darby canine kidney cells (MDCK) was investigated. With the analysis of flow cytometry, a dose-dependent accumulation of the sub-G1 peak and the G0/G1-phase arrested in cell cycle, and time-dependent induction of apoptosis after staining with Annexin V-Fluorescein and propidium iodide were observed. After the treatment of cells with p-PD, dose dependent DNA fragmentation shown by gel electrophoresis, the reduction of membrane potential (DeltaPsim) by mitochondria membrane depolarization and the increase of the expression of p53 protein in cells, suggested that the effect of p-PD on overall viability and cell numbers is mediated by an increase in apoptosis.
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PMID:p-Phenylenediamine induces p53-mediated apoptosis in Mardin-Darby canine kidney cells. 1646 77


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