Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • DKFZ Publication Database  (1,190)
  • IN-VIVO  (1,190)
Collection
  • DKFZ Publication Database  (1,190)
Keywords
  • 1
    Keywords: EXPRESSION ; IN-VIVO ; GENE ; transcription ; METABOLISM ; MICE ; NUCLEAR RECEPTORS ; LIVER RECEPTOR HOMOLOG-1 ; LRH-1 ; LIVER-RECEPTOR-HOMOLOG-1
    Abstract: Reverse cholesterol transport (RCT) is an antiatherogenic process in which excessive cholesterol from peripheral tissues is transported to the liver and finally excreted from the body via the bile. The nuclear receptor liver receptor homolog 1 (LRH-1) drives expression of genes regulating RCT, and its activity can be modified by different posttranslational modifications. Here, we show that atherosclerosis-prone mice carrying a mutation that abolishes SUMOylation of LRH-1 on K289R develop less aortic plaques than control littermates when exposed to a high-cholesterol diet. The mechanism underlying this atheroprotection involves an increase in RCT and its associated hepatic genes and is secondary to a compromised interaction of LRH-1 K289R with the corepressor prospero homeobox protein 1 (PROX1). Our study reveals that the SUMOylation status of a single nuclear receptor lysine residue can impact the development of a complex metabolic disease such as atherosclerosis.
    Type of Publication: Journal article published
    PubMed ID: 25176150
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    Keywords: IN-VIVO ; MAMMALIAN-CELLS ; LIVING CELLS ; EMBRYONIC STEM-CELLS ; LYSINE-9 METHYLATION ; HP1 PROTEINS ; DNA-METHYLATION ; HISTONE H3 ; CHROMATIN-REMODELING COMPLEXES ; NUCLEOSOME MODIFICATION
    Abstract: The cell establishes heritable patterns of active and silenced chromatin via interacting factors that set, remove, and read epigenetic marks. To understand how the underlying networks operate, we have dissected transcriptional silencing in pericentric heterochromatin (PCH) of mouse fibroblasts. We assembled a quantitative map for the abundance and interactions of 16 factors related to PCH in living cells and found that stably bound complexes of the histone methyltransferase SUV39H1/2 demarcate the PCH state. From the experimental data, we developed a predictive mathematical model that explains how chromatin-bound SUV39H1/2 complexes act as nucleation sites and propagate a spatially confined PCH domain with elevated histone H3 lysine 9 trimethylation levels via chromatin dynamics. This "nucleation and looping" mechanism is particularly robust toward transient perturbations and stably maintains the PCH state. These features make it an attractive model for establishing functional epigenetic domains throughout the genome based on the localized immobilization of chromatin-modifying enzymes.
    Type of Publication: Journal article published
    PubMed ID: 25134515
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Keywords: EXPRESSION ; IN-VIVO ; PATHWAY ; LUNG-CANCER ; ACTIVATION ; RADIATION-THERAPY ; chemotherapy ; SQUAMOUS-CELL CARCINOMA ; CISPLATIN ; tumor microenvironment ; HIF-1 ; GLUCOSE-METABOLISM ; UNFAVORABLE PROGNOSIS ; HUMAN TUMOR XENOGRAFT ; HIF-1-ALPHA ; Local tumor control ; Fractionated radiation ; HIF pathway inhibition ; INDUCIBLE FACTOR-1-ALPHA
    Abstract: BACKGROUND: The transcription factor hypoxia-inducible factor-1 (HIF-1) pathway plays an important role in tumor response to cytotoxic treatments. We investigated the effects of a novel small molecule inhibitor of mitochondrial complex I and hypoxia-induced HIF-1 activity BAY-87-2243, on tumor microenvironment and response of human squamous cell carcinoma (hSCC) to clinically relevant fractionated radiotherapy (RT) with and without concomitant chemotherapy. METHODS: When UT-SCC-5 hSCC xenografts in nude mice reached 6 mm in diameter BAY-87-2243 or carrier was administered before and/or during RT or radiochemotherapy with concomitant cisplatin (RCT). Local tumor control was evaluated 150 days after irradiation and the doses to control 50% of tumors (TCD50) were compared between treatment arms. Tumors were excised at different time points during BAY-87-2243 or carrier treatment for western blot and immunohistological investigations. RESULTS: BAY-87-2243 markedly decreased nuclear HIF-1alpha expression and pimonidazole hypoxic fraction already after 3 days of drug treatment. BAY-87-2243 prior to RT significantly reduced TCD50 from 123 to 100 Gy (p=0.037). Additional BAY-87-2243 application during RT did not decrease TCD50. BAY-87-2243 before and during radiochemotherapy did not improve local tumor control. CONCLUSIONS: Pronounced reduction of tumor hypoxia by application of BAY-87-2243 prior to RT improved local tumor control. The results demonstrate that radiosensitizing effect importantly depends on treatment schedule. The data support further investigations of HIF-1 pathway inhibitors for radiotherapy and of predictive tests to select patients who will benefit from this combined treatment.
    Type of Publication: Journal article published
    PubMed ID: 25234922
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Keywords: PROTEOMICS ; molecular ; chemosensitivity ; VOLUME ; imaging ; MODELS ; MODEL ; IN-VIVO ; SERIES ; REGULATOR
    Type of Publication: Book chapter
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Keywords: IN-VITRO ; IN-VIVO ; VITRO ; VIVO ; review ; TUMORIGENESIS ; PREVENTS ; in vitro
    Type of Publication: Journal article epub ahead of print
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    Keywords: MM3 ; therapeutic ; TEMPERATURE ; ACCURATE ; intensity ; HIGH-RESOLUTION ; ultrasound ; GUIDANCE ; MAGNETIC-RESONANCE ; sensitivity ; PERFORMANCE ; PROBE ; VIVO ; IN-VIVO ; tumor ; treatment ; MR ; MRI ; TUMORS ; RESOLUTION
    Abstract: High intensity contact ultrasound (HICU) under MRI guidance may provide minimally invasive treatment of endocavitary digestive tumors (colon/rectum). In this study, opposed-solenoid receiver-only coils were integrated into an endoscopic phased array ultrasound probe to offer high resolution MRI guidance of thermotherapy. The improvement of the image quality and temperature monitoring and control using this device has been investigated in- vivo, on a clinical 1.5T. The comparison endocavitary/external standard coils (voxel: 0.88 x 0.88 x 8 mm3) showed a sensitivity gain up to a factor 4, at the limit of the cooling balloon. Infra-millimeter resolution became feasible for fast MR thermometry while providing an excellent SDT. The endoscopic device was actively operated under automatic temperature control, demonstrating accurate performance.
    Type of Publication: Proceeding
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    Keywords: SPECTROSCOPY ; MAGNETIC-RESONANCE ; FREQUENCIES ; PARAMETERS ; IDENTIFICATION ; NMR ; NMR-SPECTROSCOPY ; MODULATION ; WHOLE-BODY ; SPECTRA ; CANCER ; IN-VIVO ; VIVO ; MR ; RESOLUTION ; TIME ; cancer research ; glutamine ; WELL ; TIMES ; 3
    Abstract: Previously, it has been shown that glutamate can be distinguished from glutamine when their zero-quantum coherence (ZQC) modulation frequencies as well as their chemical shift values are used as identification parameters in 2D spectra. However, acquisition times for such spectra exceeded four hours. We now show that by recording 2D spectra, which are undersampled along the ZCQ modulation frequency axis and then applying a Fourier Shift, glutamate can be distinguished from glutamine in 50 minutes. We demonstrate this on a healthy volunteer using a 3 Tesla whole-body MR tomograph and show that there is no loss in resolution.
    Type of Publication: Proceeding
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    facet.materialart.
    facet.materialart.
    Taylor & Francis Group CRC Pre
    Keywords: PHASE ; TECHNOLOGY ; technique ; DRUG DEVELOPMENT ; clinical studies ; in vivo ; EXTENT ; COMPOUND ; CLINICAL-APPLICATION ; pharmaceutical industry ; STEM ; DISORDERS ; development ; DRUG DISCOVERY ; INCREASE ; DISEASE ; DISEASES ; INFORMATION ; imaging ; validation ; RESOLUTION ; DRUG ; ARTHRITIS ; CANCER ; IN-VIVO ; THERAPY ; VIVO ; MR ; MRI ; TRANSPLANTATION ; INTERVENTION ; DISCOVERY ; MAGNETIC-RESONANCE ; TARGET ; IDENTIFICATION ; STAGE
    Abstract: Imaging technologies are receiving much attention in the pharmaceutical industry because of their potential for accelerating drug discovery and development. Magnetic Resonance (MR) Imaging is one of the principal modalities since it allows anatomical, functional, metabolic, and to a certain extent even target-related information to be gathered in vivo at high resolution, favouring the characterization of a disease state and the corresponding drug intervention. The non-invasiveness of MR strengthens the link between preclinical and clinical pharmaceutical research, contributing to improve the characterization of compound effects in early stages of the discovery process in order to increase the chances of success in later phases of drug development. Edited by a leading researcher in MR technology, with contributions from foremost experts in academia and the pharmaceutical industry, this title illustrates the use of MR techniques throughout the drug discovery and development process, from target identification and validation to clinical studies. Numerous chapters focus on individual disease areas, including neurological, cardiac, and pulmonary disorders, cancer studies, diabetes, arthritis, solid organ transplantation, and stem cell-based therapies, showing that different imaging solutions are needed for specific organs
    Type of Publication: Book chapter
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    Keywords: human brain ; in vivo ; imaging ; brain ; human ; IN-VIVO ; VIVO
    Type of Publication: Book chapter
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    Keywords: gene transfer ; GENE-TRANSFER ; GENE-EXPRESSION ; TUMORS ; GENE ; EXPRESSION ; tumor ; IN-VIVO ; imaging ; molecular imaging ; gene expression ; BIOLOGY ; TRACER ; MALIGNANT-TUMORS ; molecular ; PHAGE DISPLAY ; PHAGE
    Type of Publication: Book chapter
    Signatur Availability
    BibTip Others were also interested in ...
  • 11
    Keywords: ESTROGEN ; estrogen receptor ; in vivo ; THERAPIES ; ESTROGEN-RECEPTOR ; mechanisms ; DISSECTION ; LIGANDS ; RECEPTOR ; IN-VIVO ; THERAPY ; VIVO ; MECHANISM ; LIGAND
    Type of Publication: Book chapter
    Signatur Availability
    BibTip Others were also interested in ...
  • 12
    Keywords: RECEPTOR ; SPECTRA ; ANGIOGENESIS ; CANCER ; GROWTH ; GROWTH-FACTOR ; IN-VITRO ; INHIBITOR ; proliferation ; SURVIVAL ; tumor ; ADVANCED SOLID TUMORS ; AGENTS ; ANGIOSTATIN ; BLOOD ; carcinoma ; CELL ; CELL LUNG-CANCER ; CELL-PROLIFERATION ; CLINICAL-TRIAL ; COMBINATION ; DOPPLER ; ENDOTHELIAL GROWTH-FACTOR ; evaluation ; FACTOR RECEPTOR ; Germany ; human ; IN-VIVO ; INHIBITION ; KINASE ; LUNG ; MICROSCOPY ; MICROVESSEL DENSITY ; MODEL ; MODELS ; neoplasms ; PATHWAY ; PATHWAYS ; PERFUSION ; PHASE-I ; PROSTATE ; RECOMBINANT HUMAN ENDOSTATIN ; THERAPY ; TOXICITY ; tumor growth ; TYROSINE KINASE ; VITRO ; VIVO
    Abstract: The multifaceted nature of the angiogenic process in malignant neoplasms suggests that protocols that combine antiangiogenic agents may be more effective than single-agent therapies. However it is unclear which combination of agents would be most efficacious and will have the highest degree of synergistic activity while maintaining low overall toxicity. Here we investigate the concept of combining a "direct" angiogenesis inhibitor (endostatin) with an "indirect" antiangiogenic compound [SU5416, a vascular endothelial growth factor receptor 2 (VEGFR2) receptor tyrosine kinase (RTK) inhibitor]. These angiogenic agents were more effective in combination than when used alone in vitro (endothelial cell proliferation, survival, migration/invasion, and tube formation tests) and in vivo. The combination of SU5416 and low-dose endostatin further reduced tumor growth versus monotherapy in human prostate (M), lung (A459), and glioma (U87) xenograft models, and reduced functional microvessel density, tumor microcirculation, and blood perfusion as detected by intravital microscopy and contrast-enhanced Doppler ultrasound. One plausible explanation for the efficacious combination could be that, whereas SU5416 specifically inhibits vascular endothelial growth factor signaling, low-dose endostatin is able to inhibit a broader spectrum of diverse angiogenic pathways directly in the endothelium. The direct antiangiogenic agent might be able to suppress alternative angiogenic pathways up-regulated by the tumor in response to the indirect, specific pathway inhibition. For future clinical evaluation of the concept, a variety of agents with similar mechanistic properties could be tested
    Type of Publication: Journal article published
    PubMed ID: 14695206
    Signatur Availability
    BibTip Others were also interested in ...
  • 13
    Keywords: DOPPLER ; Germany ; IN-VIVO ; MODEL ; MODELS ; CT ; VOLUME ; NEW-YORK ; ACCURACY ; computed tomography ; HEART ; INTEROBSERVER VARIABILITY ; PIGS ; RESOLUTION ; SURGERY ; validation
    Abstract: Background. Cardiac functional assessment represents the basis for diagnostics and cardiac operation planning. Spiral computed tomography (CT) combines the advantages of three-dimensional imaging and high temporal resolution when using gating techniques. However, in vivo validation data of this novel imaging technology are lacking. The purpose of this study was to validate in vivo the new imaging method using retrospective gating and to evaluate the clinical usefulness of the achieved temporal resolution. Methods. In domestic pigs (n = 10, weight 35 to 40 kg) a flowmeter was placed surgically on the ascending aorta. Flow velocity integrated over systole served as the gold standard for left ventricular (LV) stroke volume (LVSV-FM). CT signal, projection data, pacemaker signal, and flow velocity were recorded simultaneously at constant heart rate (pacemaker, 90 beats per minute). End-systolic and end-diastolic frames were calculated by retrospective gating. LV volumes were traced, the difference representing CT stroke volume (LVSV-CT). Image data were three-dimensionally reconstructed using ray- tracing. Results. Temporal resolution was 170 ms. Correlation of stroke volumes was high (r = 0.94, mean difference 1.75 mL). Intraobserver (0.49 mL, for LVEDV, 0.31 for LVESV) and interobserver variability (p = 0.21 and p = 0.06, respectively) were low. Postprocessing resulted in four-dimensional beating- heart models useful for operation planning. Conclusions. Spiral CT using retrospective gating was validated in vivo. Clinically acceptable temporal resolution and accuracy in determining cardiac stroke volumes were found. As a true volumetric imaging modality the method may now play an important role in computer- assisted diagnostics and surgery. (C) 2003 by The Society of Thoracic Surgeons
    Type of Publication: Journal article published
    PubMed ID: 12645712
    Signatur Availability
    BibTip Others were also interested in ...
  • 14
    Keywords: CELLS ; EXPRESSION ; INHIBITOR ; tumor ; IN-VIVO ; GENE ; TUMORS ; ACCUMULATION ; CATECHOLAMINES ; gene therapy ; human norepinephrine transporter ; I-123 MIBG ; LINES ; METAIODOBENZYLGUANIDINE UPTAKE ; MIBG uptake ; MICE ; NEUROBLASTOMA-CELLS ; NORADRENALINE TRANSPORTER ; NUCLEAR-MEDICINE ; radiation ; RELEASE ; STORAGE ; TIME ; TRANSDUCTION
    Abstract: The transport of MIBG by the human norepinephrine transporter (hNET) seems to be the critical step in the treatment of MIBG- concentrating tumors. Therefore, we investigated whether the accumulation of MIBG may be induced by retroviral transect on of the hNET gene in Morris hepatoma cells. Methods: A bicistronic retroviral vector for the transfer of the hNET coding sequence and the hygromycin resistance gene was generated. Morris hepatoma cells (MH3924A) were infected with the respective retroviral particles, and hNET-expressing cell lines MHhNEThyg1 to MHhNEThyg9 were obtained through hygromycin selection. The uptake of H-3-norepinephrine or I-131-MIBG and the efflux of I-131-MIBG were determined in transfected and wild-type cells. In addition, the I-131-MIBG distribution was monitored in nude mice and rats bearing wild-type and hNET- expressing hepatomas. Results: hNET-expressing hepatoma cell lines accumulated up to 36 times more norepinephrine than did wild-type cells and 8 times more than did hNET-expressing neuroblastoma cell line SK-N-SH. The addition of nisoxetine, a selective inhibitor of noradrenaline uptake, inhibited norepinephrine uptake. Maximal I-131-MIBG accumulation was observed 2 h after incubation and was followed by 43% efflux within 4 h after the I-131-MIBG-containing medium had been removed. In vivo experiments performed with nude mice bearing both hNET-expressing and wild-type tumors showed a 10-fold- higher accumulation of I-131-MIBG in transfected tumors than in wild-type tumors. The ex vivo calculations revealed doses of 605 and 75 mGy in hNET-expressing and wild-type tumor tissues, respectively. Conclusion: Transduction of the hNET gene enables Morris hepatoma cells to accumulate norepinephrine and MIBG. However, the retention of MIBG is brief; therefore, the absorbed dose of radiation in vivo is not expected to be therapeutically effective
    Type of Publication: Journal article published
    PubMed ID: 12791828
    Signatur Availability
    BibTip Others were also interested in ...
  • 15
    Keywords: RECEPTOR ; CELLS ; EXPRESSION ; IN-VITRO ; proliferation ; IN-VIVO ; MODEL ; DISEASE ; DISTINCT ; MICE ; ACTIVATED MACROPHAGES ; ACTIVATION ; COMPLEX ; CRESCENTIC GLOMERULONEPHRITIS ; INJURIES ; LIGAND ; MESANGIAL CELLS ; MONOCYTE ARREST ; NEPHRITIS ; NITRIC-OXIDE ; RANTES ; RESPONSES
    Abstract: The chemokine CC chemokine ligand (CCL)5/RANTES as well as its respective receptor CCR5 mediate leukocyte infiltration during inflammation and are up-regulated early during the course of glomerulonephritis (GN). We tested the effects of the two CCL5/RANTES blocking analogs, Met-RANTES and amino-oxypentane- RANTES, on the course of horse apoferritin (RAF)induced GN. HAF-injected control mice had proliferative GN with mesangial immune complex deposits of IgG and HAF. Daily i.p. injections of Met-RANTES or amino-oxypentane-RANTES markedly reduced glomerular cell proliferation and glomerular macrophage infiltration, which is usually associated with less glomerular injury and proteinuria in RAF-GN. Surprisingly, however, RAF-GN mice treated with both analogs showed worse disease with mesangiolysis, capillary obstruction, and nephrotic range albuminuria. These findings were associated with an enhancing effect of the CCL5/RANTES analogs on the macrophage activation state, characterized by a distinct morphology and increased inducible NO synthetase expression in vitro and in vivo, but a reduced uptake of apoptotic cells in vivo. The Immoral response and the Th1/Th2 balance in HAF-GN and mesangial cell proliferation in vitro were not affected by the CCL5/RANTES analogs. We conclude that, despite blocking local leukocyte recruitment, chemokine analogs can aggravate some specific disease models, most likely due to interactions with systemic immune reactions, including the removal of apoptotic cells and inducible NO synthetase expression
    Type of Publication: Journal article published
    PubMed ID: 12759447
    Signatur Availability
    BibTip Others were also interested in ...
  • 16
    Keywords: CANCER ; CELLS ; EXPRESSION ; IN-VIVO ; LUNG-CANCER ; DNA adducts ; RISK ; GENE ; LINES ; ACTIVATION ; DNA ; 3-aminobenzanthrone ; 3-nitrobenzanthrone ; AIR ; CARCINOGENESIS ; CYP1A2 ; CYTO-TOXIC METABOLITES ; DIESEL EXHAUST ; DNA ADDUCT FORMATION ; ENVIRONMENTAL CONTAMINANT 3-NITROBENZANTHRONE ; GENETIC POLYMORPHISMS ; HETEROCYCLIC AMINES ; HETEROLOGOUS EXPRESSION ; HUMAN CYTOSOLIC SULFOTRANSFERASES ; IONS ; metabolic activation ; NAT : SULT ; nitro-PAH ; P-32- postlabeling ; PHENOL SULFOTRANSFERASES ; POSTLABELING ANALYSIS
    Abstract: 3-Nitrobenzanthrone (3-NBA) is a potent mutagen and suspected human carcinogen identified in diesel exhaust and ambient air pollution. 3-Aminobenzanthrone (3-ABA), 3- acetylaminobenzanthrone (3-Ac-ABA) and N-acetyl-N-hydroxy-3- aminobenzanthrone (N-Ac-N-OH-ABA) have been identified as 3-NBA metabolites. Recently we found that 3-NBA and its metabolites (3-ABA, 3-Ac-ABA and N-Ac-N-OH-ABA) form the same DNA adducts in vivo in rats. In order to investigate whether human cytochrome P450 (CYP) enzymes (i.e., CYPIA2), human N,O- acetyltransferases (NATs) and sulfotransferases (SULTs) contribute to the metabolic activation of 3-NBA and its metabolites we developed a panel of Chinese hamster V79MZ-hIA2 derived cell lines expressing human CYPIA2 in conjunction with human NATI, NAT2, SULTIAI or SULTIA2, respectively. Cells were treated with 0.01, 0.1 or I muM 3-NBA, or its metabolites (3- ABA, 3-Ac-ABA and N-Ac-N-OH-ABA). Using both enrichment versions of the P-32-postlabeling assay, nuclease P I digestion and butanol extraction, essentially 4 major and 2 minor DNA adducts were detected in the appropriate cell lines with all 4 compounds. The major ones were identical to those detected in rat tissue; the adducts lack an N-acetyl group. Human CYPIA2 was required for the metabolic activation of 3-ABA and 3-Ac-ABA (probably via N-oxidation) and enhanced the activity of 3-NBA (probably via nitroreduction). The lack of acetylated adducts suggests N-deacetylation of 3-Ac-ABA and N-Ac-N-OH-ABA. Thus, N-hydroxy-3-aminobenzanthrone (N-OH-ABA) appears to be a common intermediate for the formation of the electrophilic arylnitrenium ions capable of reacting with DNA. Human NAT I and NAT2 as well as human SULTIAI and SULTIA2 strongly contributed to the high genotoxicity of 3-NBA and its metabolites. Moreover, N,O-acetyltransfer reactions catalyzed by human NATs leading to the corresponding N-acetoxyester may be important in the bioactivation of N-Ac-N-OH-ABA. As human exposure to 3-NBA is likely to occur primarily via the respiratory tract, expression of CYPs, NATs and SULTs in respiratory tissues may contribute significantly and specifically to the metabolic activation of 3-NBA and its metabolites. Consequently, polymorphisms in these genes could be important determinants of lung cancer risk from 3-NBA
    Type of Publication: Journal article published
    PubMed ID: 12740904
    Signatur Availability
    BibTip Others were also interested in ...
  • 17
    Keywords: RECEPTOR ; EXPRESSION ; GROWTH ; IN-VIVO ; PATHWAYS ; PROTEIN ; SACCHAROMYCES-CEREVISIAE ; COMPLEX ; COMPLEXES ; BINDING ; IDENTIFICATION ; Saccharomyces cerevisiae ; YEAST ; lifestyle ; BETA ; CONSERVATION ; EGG EXTRACTS ; GTPASE RAN ; IMPORTIN-ALPHA ; LOCALIZATION ; MESSENGER-RNA EXPORT ; NUCLEAR EXPORT RECEPTOR ; NUCLEUS ; TRANSPORT FACTOR ; XENOPUS
    Abstract: The small Ras-like GTPase Ran plays an essential role in the transport of macromolecules in and out of the nucleus and has been implicated in spindle (1, 2) and nuclear envelope formation (3, 4) during mitosis in higher eukaryotes. We identified Saccharomyces cerevisiae open reading frame YGL164c encoding a novel RanGTP-binding protein, termed Yrb30p. The protein competes with yeast RanBP1 (Yrb1p) for binding to the GTP-bound form of yeast Ran (Gsp1p) and is, like Yrb1p, able to form trimeric complexes with RanGTP and some of the karyopherins. In contrast to Yrb1p, Yrb30p does not coactivate but inhibits RanGAP1(Rna1p)-mediated GTP hydrolysis on Ran, like the karyopherins. At steady state, Yrb30p localizes exclusively to the cytoplasm, but the presence of a functional nuclear export signal and the localization of truncated forms of Yrb30p suggest that the protein shuttles between nucleus and cytoplasm and is exported via two alternative pathways, dependent on the nuclear export receptor Xpo1p/Crm1p and on RanGTP binding. Whereas overproduction of the full-length protein and complete deletion of the open reading frame reveal no obvious phenotype, overproduction of C-terminally truncated forms of the protein inhibits yeast vegetative growth. Based on these results and the exclusive conservation of the protein in the fungal kingdom, we hypothesize that Yrb30p represents a novel modulator of the Ran GTPase switch related to fungal lifestyle
    Type of Publication: Journal article published
    PubMed ID: 12578832
    Signatur Availability
    BibTip Others were also interested in ...
  • 18
    Keywords: APOPTOSIS ; CANCER ; CANCER CELLS ; CELLS ; EXPRESSION ; INHIBITOR ; tumor ; TUMOR-CELLS ; CELL ; Germany ; human ; IN-VIVO ; INHIBITION ; DEATH ; GENE ; GENE-EXPRESSION ; RNA ; TUMORS ; ACTIVATION ; PROTEIN FAMILY ; INDUCTION ; SUSCEPTIBILITY ; TARGET ; gene expression ; resistance ; HUMAN-TUMORS ; STIMULI ; CANCER-CELLS ; DELIVERY ; MAMMALIAN-CELLS ; SMALL INTERFERING RNAS ; doxorubicin ; HUMAN-TUMOR-CELLS ; IAP PROTEINS ; POSITIVE CANCER-CELLS ; RNA interference,inhibitors of apoptosis,chemotherapy,HeLa,melanoma ; STRATEGIES
    Abstract: Increased resistance to apoptosis is a hallmark of many tumor cells. The functional inhibition of specific antiapoptotic factors may provide a rational basis for the development of novel therapeutic strategies. We investigated here whether the RNA interference (RNAi) technology could be used to increase the apoptotic susceptibility of cancer cells. As a molecular target, we chose the antiapoptotic livin (ML-IAP, KIAP) gene, which is expressed in a subset of human tumors. We identified vector-borne small interfering (si)RNAs, which could efficiently block endogenous livin gene expression. Silencing of livin was associated with caspase-3 activation and a strongly increased apoptotic rate in response to different proapoptotic stimuli, such as doxorubicin, UV-irradiation, or TNFalpha. The effects were specific for Livin-expressing tumor cells. Our results (i) provide direct evidence that the intracellular interference with livin gene expression resensitizes human tumor cells to apoptosis, (ii) define the livin gene as a promising molecular target for therapeutic inhibition, and (iii) show that the livin gene is susceptible to efficient and specific silencing by the siRNA technology
    Type of Publication: Journal article published
    PubMed ID: 14614456
    Signatur Availability
    BibTip Others were also interested in ...
  • 19
    Keywords: CANCER ; IN-VITRO ; tumor ; AGENTS ; Germany ; IN-VIVO ; INHIBITION ; screening ; SYSTEM ; SYSTEMS ; RISK ; ENZYMES ; DRUG ; NITRIC-OXIDE ; murine ; RISK-FACTORS ; CARCINOGENESIS ; INDUCTION ; KERATINOCYTES ; mechanisms ; culture ; IDENTIFICATION ; prevention ; risk factors ; MODULATION ; RISK FACTOR ; butyrate ; HEPATOMA ; fatty acids ; FATTY-ACIDS ; NF-kappa B ; ALCOHOL ; SODIUM-BUTYRATE ; curcumin ; ORNITHINE DECARBOXYLASE ; ANTIOXIDANT ; bioassay systems ; cancer chernoprevention ; CONSTITUENTS ; iNOS ; PEITC ; SULFORAPHANE ; SUPEROXIDE
    Abstract: Identification and use of effective cancer chemopreventive agents have become an important issue in public health-related research. For identification of potential cancer chemopreventive constituents we have set up a battery of cell- and enzyme-based in vitro marker systems relevant for prevention of carcinogenesis in vivo. These systems include modulation of drug metabolism (inhibition of Cyp1A activity, induction of NAD(P)H:quinone reductase (QR) activity in Hepalclc7 murine hepatoma cell culture), determination of radical scavenging (DPPH scavenging) and antioxidant effects (scavenging of superoxide anion-, hydroxyl- and peroxyl- radicals), anti-inflammatory mechanisms (inhibition of lipopolysaccharide (LPS)-mediated nitric oxide (NO) generation by inducible NO synthase (iNOS) in Raw 264.7 murine macrophages, cyclooxygenase-1 (Cox-1) inhibition), and anti- tumor promoting activities (inhibition of phorbol ester-induced ornithine decarboxylase (ODC) activity in 308 murine keratinocytes). We have tested a series of known chemopreventive substances belonging to several structural classes as reference compounds for the identification of novel chemopreventive agents or mechanisms. These include organosulfur compounds (phenethylisothiocyanate (PEITC), diallylsulfide, diallyldisulfide), terpenes (limonene, perillyl alcohol, oleanolic acid, 18-beta-glycyrrhetinic acid), short- chain fatty acids (sodium butyrate), indoles (indole-3- carbinol), isoflavonoids (quercetin, silymarin, genistein), catechins ((-)-epigallocatechin gallate (EGCG)), simple phenols (ellagic acid, resveratrol, piceatannol, curcumin), pharmaceutical agents (piroxicam, acetylsalicylic acid, tamoxifen), and vitamins/derivatives (ascorbic acid, Trolox). We confirmed known chemopreventive mechanisms of these compounds. Additionally, we could demonstrate the usefulness of our approach by identification of hitherto unknown mechanisms of selected agents. As an example, we detected anti- inflammatory properties of PEITC, based on NF-kappaB-mediated inhibition of NO production. Further, PEITC inhibited phorbol ester-induced superoxide anion radical production in granulocytes, and ODC induction in the 308 cell line. These mechanisms might contribute to the chemopreventive potential of PEITC. (C) 2002 Elsevier Science B.V. All rights reserved
    Type of Publication: Journal article published
    PubMed ID: 12628514
    Signatur Availability
    BibTip Others were also interested in ...
  • 20
    Keywords: RECEPTOR ; IN-VIVO ; GENE ; PROTEIN ; animals ; PROMOTERS ; MAMMALIAN-CELLS ; COMPLEMENTATION ; LUCIFERASE ; REPORTER GENE-EXPRESSION
    Abstract: Genomic research is expected to generate new types of complex observational data, changing the types of experiments as well as our understanding of biological processes. The investigation and definition of relationships among proteins is essential for understanding the function of each gene and the mechanisms of biological processes that specific genes are involved in. Recently, a study by Paulmurugan et al. demonstrated a tool for in vivo noninvasive imaging of protein-protein interactions and intracellular networks
    Type of Publication: Journal article published
    PubMed ID: 12788540
    Signatur Availability
    BibTip Others were also interested in ...
  • 21
    Keywords: CELLS ; EXPRESSION ; IN-VITRO ; CELL ; human ; IN-VIVO ; VITRO ; VIVO ; NETWORK ; GENE ; PROTEIN ; PROTEINS ; TIME ; INFECTION ; RAT ; CONTRAST ; STAGE ; DISRUPTION ; MUTATION ; MUTATIONS ; MUSCLE ; ASSEMBLY PROPERTIES ; SERIES ; GREEN FLUORESCENT PROTEIN ; ORGANIZATION ; ADENOVIRUS ; ALPHA-B-CRYSTALLIN ; DILATED CARDIOMYOPATHY ; EPIDERMOLYSIS-BULLOSA SIMPLEX ; INTERMEDIATE-FILAMENT PROTEINS ; MICE LACKING DESMIN ; MUSCULAR-DYSTROPHY ; SKELETAL MYOPATHY ; SMOOTH-MUSCLE ; Z-DISCS
    Abstract: Mutations in desmin have been associated with a subset of human myopathies. Symptoms typically appear in the second to third decades of life, but in the most severe cases can manifest themselves earlier. How desmin mutations lead to aberrant muscle function, however, remains poorly defined. We created a series of four mutations in rat desmin and tested their in vitro filament assembly properties. RDM-G, a chimera between desmin and green fluorescent protein, formed protofilament-like structures in vitro. RDM-1 and RDM-2 blocked in vitro assembly at the unit-length filament stage, while RDM-3 had more subtle effects on assembly. When expressed in cultured rat neonatal cardiac myocytes via adenovirus infection, these mutant proteins disrupted the endogenous desmin filament to an extent that correlated with their defects in in vitro assembly properties. Disruption of the desmin network by RDM-1 was also associated with disruption of plectin, myosin, and a-actinin organization in a significant percentage of infected cells. In contrast, expression of RDM-2, which is similar to previously characterized human mutant desmins, took longer to disrupt desmin and plectin organization and had no significant effect on myosin or alpha-actinin organization over the 5-day time course of our studies. RDM-3 had the mildest effect on in vitro assembly and no discernable effect on either desmin, plectin, myosin, or a-actinin organization in vivo. These results indicate that mutations in desmin have both direct and indirect effects on the cytoarchitecture of cardiac myocytes
    Type of Publication: Journal article published
    PubMed ID: 12529857
    Signatur Availability
    BibTip Others were also interested in ...
  • 22
    Keywords: IN-VITRO ; IONIZING-RADIATION ; IRRADIATION ; CELL ; Germany ; human ; IN-VIVO ; KINASE ; PATHWAY ; VITRO ; VIVO ; SITE ; PROTEIN ; radiation ; ACTIVATION ; COMPLEX ; COMPLEXES ; DNA ; CARCINOGENESIS ; cell cycle ; CELL-CYCLE ; CYCLE ; PHOSPHORYLATION ; MUTANT ; LESIONS ; PROGRESSION ; CYCLE PROGRESSION ; DAMAGE ; DNA-DAMAGE ; DEGRADATION ; ATR ; CHK1 ; CYCLE CONTROL ; G(1)/S TRANSITION ; PROTEASOME ; S-PHASE ; serine
    Abstract: The human Cdc25A phosphatase plays a pivotal role at the G(1)/S transition by activating cyclin E and A/Cdk2 complexes through dephosphorylation. In response to ionizing radiation, Cdc25A is phosphorylated by both Chk1 and Chk2 on Ser-123. This in turn leads to ubiquitylation and rapid degradation of Cdc25A by the proteasome resulting in cell cycle arrest. We found that in response to UV irradiation, Cdc25A is phosphorylated at a different serine residue, Ser-75. Significantly, Cdc25A mutants carrying alanine instead of either Ser-75 or Ser-123 demonstrate that only Ser-75 mediates protein stabilization in response to UV-induced DNA damage. As a consequence, cyclin E/Cdk2 kinase activity was high. Furthermore, we find that Cdc25A was phosphorylated by Chk1 on Ser-75 in vitro and that the same site was also phosphorylated in vivo. Taken together, these data strongly suggest that phosphorylation of Cdc25A on Ser-75 by Chk1 and its subsequent degradation is required to delay cell cycle progression in response to UV-induced DNA lesions
    Type of Publication: Journal article published
    PubMed ID: 12759351
    Signatur Availability
    BibTip Others were also interested in ...
  • 23
    Keywords: BLOOD ; IN-VIVO ; MODEL ; IMAGES ; liver ; TISSUE ; ACCUMULATION ; COMPLEX ; LIGAND ; COMPLEXES ; REPERFUSION ; RAT ; blood flow ; KINETICS ; ISCHEMIA ; myocardium ; BAT ligands ; BMS-181321 ; HYPOXIC TISSUE MARKER ; ischaemia ; nitroimidazole ; RAT-HEART ; TC-99M-MIBI ; technetium ; TECHNETIUM-99M-NITROIMIDAZOLE BMS181321
    Abstract: Myocardial perfusion single-photon emission tomography (SPET) performed with cationic technetium-99m complexes indicates ischaemic areas as cold lesions. By contrast, nitroimidazole derivatives labelled with fluorine-18 or Tc-99m have recently shown promising results for hot spot imaging of ischaemic myocardium. This study evaluates (TcO)-Tc-99m(BAT-NI), a new Tc-99m complex comprising the nitroimidazole ligand, 2,10- dimercapto-2,10-dimethyl-4,8-diaza-6-[4-(2-nitroimidazolyl)- butyl]undecane, in a low-flow in vivo model of myocardial ischaemia in thoracotomised rats. To elucidate the influence of the 2-nitroimidazole group on ischaemia-induced uptake, comparisons with ligand derivatives were performed where (a) the 2-nitro group was deleted [(TcO)-Tc-99m(BAT-I)], (b) the 2- nitroimidazole functionality was replaced by a Br atom [(TcO)- Tc-99m(BAT-Br)] and (c) the (TcO)-Tc-99m(BAT) moiety was replaced by an iodine-125 iodophenoxybutyl ligand ((IP)-I-125- NI). The radiolabelled compounds were i.v. injected 15 min after reducing resting myocardial blood flow by 50-60% and the uptake of radioactivity was assessed 90 min post injection. Autoradiography of left ventricular short-axis slices showed median uptake ratios of ischaemic/non-ischaemic myocardium (I/N) of 3.4, 4.5 and 3.4 for (TcO)-Tc-99m(BAT-NI), 99mTcO(BAT- I) and (TcO)-Tc-99m(BAT-Br), respectively. In contrast, (IP)-I- 125-NI was not preferentially taken up by ischaemic myocardium. Accumulation of (TcO)-Tc-99m(BAT-NI) in ischaemic heart regions was comparable to that in the liver. Biodistribution studies showed a median uptake of 0.65% ID/g of (TcO)-Tc-99m(BAT-NI) in ischaemic tissue and an IN of 3.3. On planar images of the thorax and upper abdomen the ischaemic hearts were visualised faintly; the median heart to lung count ratio for (TcO)-Tc- 99m(BAT-NI) was 1.7, and the median heart to liver count ratio was 1.0. We conclude that uptake of (TcO)-Tc-99m(BAT-NI) in ischaemic myocardium does not depend on the nitroimidazole moiety but is intrinsic to the BAT complex. Clinical use of the (TcO)-Tc-99m(BAT)-labelled tracers seems unlikely owing to their low uptake and their low ischaemic tissue contrast on planar images in vivo
    Type of Publication: Journal article published
    PubMed ID: 12574972
    Signatur Availability
    BibTip Others were also interested in ...
  • 24
    Keywords: AB-INITIO ; PEPTIDE ; SPECTRA ; IN-VITRO ; IN-VIVO ; IONS ; mechanisms ; SPECTROSCOPY ; IDENTIFICATION ; MOBILITY ; fragmentation ; PEPTIDES ; DISSOCIATION ; cyclic depsipeptide ; destruxin ; DESTRUXINS ; GLYCYLGLYCINE ; MAIN FRAGMENTATION PATHWAYS ; PROTONATED PEPTIDES ; quantum chemical calculations ; relative and total energy ; roseotoxin ; RRKM ; Trichothecium
    Abstract: High-performance liquid chromatography and tandem mass spectrometry (HPLC/MS/MS) was used for the detection of cyclic hexadepsipeptides roseotoxins produced by Trichothecium roseum. Roseotoxins were found in both submerged standard cultivation on Czapek-Dox medium and in vivo cultivation extract obtained from an apple. Roseotoxin chromatographic profiles from these two experiments were compared. Product-ion collision-induced dissociation (CID) spectra obtained on an ion trap (electrospray ionisation, ESI) were used for the identification of natural roseotoxins; A, B, C and of minor destruxins; A and B. The dissociation behavior of roseotoxins is discussed in terms of a fragmentation scheme proposed for describing the dissociation pathways of cyclic peptides. This scheme involves opening of the cyclopeptide ring via formation of oxazolone derivatives and fragmentation of the resulting linear species, which have a free N-terminus and an oxazolone ring at the C- terminus. Some aspects of this fragmentation scheme are underlined by modeling the dissociation channels of roseotoxin A using quantum chemical calculations. The structures of roseotoxin A and destruxin B were verified by nuclear magnetic resonance (NMR) spectroscopy. Structures of three new minor natural roseotoxins [Val(4)]RosA, [MeLxx(4)]RosA and [MeLxx(4)]RosB were deduced by ion cyclotron resonance Fourier transform mass spectrometry (ICR-FT-MS) and ion trap tandem mass spectrometry by examining the pre-separated roseotoxin fraction
    Type of Publication: Journal article published
    PubMed ID: 12748394
    Signatur Availability
    BibTip Others were also interested in ...
  • 25
    Keywords: carcinoma ; IN-VIVO ; METABOLISM ; murine ; colon ; CELL-LINES ; treatment ; VARIANTS ; F-19 NMR ; MAGNETIC-RESONANCE SPECTROSCOPY ; MODULATION ; THERAPEUTIC EFFICACY ; CYTO-TOXICITY ; F-19 magnetic resonance spectroscopy,5-fluorouracil,C26 murine colon carcinoma ; RAT-TUMORS ; RIF-1 TUMORS ; THYMIDYLATE SYNTHASE
    Type of Publication: Journal article published
    PubMed ID: 12915890
    Signatur Availability
    BibTip Others were also interested in ...
  • 26
    Keywords: PEPTIDE ; CELLS ; EXPRESSION ; IN-VITRO ; proliferation ; BLOOD ; CELL ; human ; IN-VIVO ; VITRO ; VIVO ; SITE ; SITES ; DISTINCT ; TISSUE ; LINES ; LIGAND ; RESPONSES ; CUTTING EDGE ; IFN-GAMMA ; INFECTION ; FAMILY ; TISSUES ; CONTRAST ; DENDRITIC CELLS ; T cell ; T cells ; T-CELL ; T-CELLS ; cytokines ; IMMUNE-RESPONSES ; STIMULATION ; EQUIVALENT ; HUMANS ; DIFFERENCE ; ESCHERICHIA-COLI ; MEDIATORS ; LINE ; STIMULI ; COLON-CANCER ; PEPTIDES ; MIGRATION ; PHENOTYPE ; leukocyte ; allogeneic ; immune response ; IMMUNE-RESPONSE ; IMMUNITY ; T lymphocyte ; PERIPHERAL-BLOOD ; PRECURSORS ; AUSTRALIA ; CD34(+) PROGENITOR CELLS ; chemokine ; CTL ; HUMAN DENDRITIC CELLS ; HUMAN PERIPHERAL-BLOOD ; INTERFERON-GAMMA ; LANGERHANS CELLS ; MONOCYTE ; OF-FUNCTION ; SUBSETS ; TOLL-LIKE RECEPTORS
    Abstract: Dendritic cells (DCs) are a family of leukocytes that initiate T- and B-cell immunity against pathogens. Migration of antigen-loaded DCs from sites of infection into draining lymphoid tissues is fundamental to the priming of T-cell immune responses. In humans, the major peripheral blood DC (PBDC) types, CD1c(+) DCs and interleukin 3 receptor-positive (IL-3R(+)) plasmacytoid DCs, are significantly expanded in vivo with the use of Flt3 ligand (FL). DC-like cells can also be generated from monocyte precursors (MoDCs). A detailed comparison of the functional potential of these types of DCs (in an autologous setting) has yet to be reported. Here, we compared the functional capacity of FL-expanded CD1c(+) PBDCs with autologous MoDCs in response to 3 different classes of stimuli: (1) proinflammatory mediators, (2) soluble CD40 ligand trimer (CD40L), and (3) intact bacteria (Escherichia coli). Significant differences in functional capacities were found with respect to changes in phenotype, migratory capacity, cytokine secretion, and T-cell stimulation. MoDCs required specific stimuli for the expression of functions. They responded vigorously to CD40L or E coli, expressing cytokines known to regulate interferon-gamma (IFN-gamma) in T cells (IL-12p70, IL-18, and IL-23), but required prostaglandin E-2 (PGE(2)) during stimulation to migrate to chemokines. In contrast, PBDCs matured in response to minimal stimulation, rapidly acquired migratory function in the absence of PGE(2)-containIng stimuli, and were low cytokine producers. Interestingly, both types of DCs were equivalent with respect to stimulation of allogeneic T-cell proliferation and presentation of peptides to cytotoxic T lymphocyte (CTL) lines. These distinct differences are of particular importance when considering the choice of DC types for clinical applications
    Type of Publication: Journal article published
    PubMed ID: 12738673
    Signatur Availability
    BibTip Others were also interested in ...
  • 27
    Keywords: Germany ; IN-VIVO ; SUPPORT ; GENE ; GENOME ; PROTEIN ; PROTEINS ; RNA ; TIME ; DNA ; FAMILY ; SUFFICIENT ; STAGE ; Drosophila ; MELANOGASTER ; DNA methylation ; EMBRYO ; FISSION YEAST ; METHYLTRANSFERASE ACTIVITY ; OVEREXPRESSION ; METHYLATION ; CATALYTIC ACTIVITY ; CYTOSINE-5 METHYLTRANSFERASES ; DE-NOVO METHYLATION ; DNA methylation,Drosophila,DNA methyltransferase,Dnmt2,Su(var)3-9 ; DNA methyltransferase ; EMBRYONIC STEM-CELLS ; EMBRYOS ; HISTONE H3 METHYLTRANSFERASE ; HYPERMETHYLATION ; LETHALITY ; MAMMALIAN DEVELOPMENT ; METHYLTRANSFERASE GENE ; SEQUENCE SPECIFICITY
    Abstract: The methylation status of Drosophila DNA has been discussed controversially over a long time. Recent evidence has provided strong support for the existence of 5-methylcytosine in DNA preparations from embryonic stages of fly development. The Drosophila genome contains a single candidate DNA methyltransferase gene that has been termed Dnmt2. This gene belongs to a widely conserved family of putative DNA methyltransferases. However, no catalytic activity has been demonstrated for any Dnmt2-like protein yet. We have now established a protocol for the immunological detection of methylated cytosine in fly embryos. Confocal analysis of immunostained embryos provided direct evidence for the methylation of embryonic DNA. In order to analyse the function of Dnmt2 in DNA methylation, we depleted the protein by RNA interference. Depletion of Dnmt2 had no detectable effect on embryonic development and resulted in a complete loss of DNA methylation. Consistently, overexpression of Dnmt2 from an inducible transgene resulted in significant genomic hypermethylation at CpT and CpA dinucleotides. These results demonstrate that Dnmt2 is both necessary and sufficient for DNA methylation in Drosophila and suggest a novel CpT/A-specific DNA methyltransferase activity for Dnmt2 proteins
    Type of Publication: Journal article published
    Signatur Availability
    BibTip Others were also interested in ...
  • 28
    Keywords: CELLS ; IN-VITRO ; tumor ; CELL ; Germany ; IN-VIVO ; KINASE ; VIVO ; PROTEIN ; MICE ; DNA ; INFECTION ; FAMILY ; CYCLE ; MEMBER ; MEMBERS ; PHOSPHORYLATION ; protein kinase ; PROTEIN-KINASE ; treatment ; TARGET ; virus ; NUCLEUS ; POLYPEPTIDE ; INVOLVEMENT ; DNA-REPLICATION ; KINASE-C ; MINUTE VIRUS ; PROTEIN-KINASE-C ; REPLICATION ; RECOMBINANT VACCINIA VIRUS ; REGULATORS ; AUTONOMOUS PARVOVIRUSES ; NONSTRUCTURAL PROTEINS ; BINDING MOTIF ; CELL POLARITY ; NS-1 PROTEIN ; VIRAL-INFECTION
    Abstract: Minute virus of mice NS1 protein is a multifunctional phosphoprotein endowed with a variety of enzymatic and regulatory activities necessary for progeny virus particle production. To regulate all of its different functions in the course of a viral infection, NS1 has been proposed to be modulated by posttranslational modifications, in particular, phosphorylation. Indeed, it was shown that the NS1 phosphorylation pattern is altered during the infectious cycle and that the biochemical profile of the protein is dependent on the phosphorylation state of the polypeptide.. Moreover, in vitro approaches have identified members of the protein kinase C (PKC) family, in particular, atypical PKC, as regulators of viral DNA replication through the phosphorylation of NS1 residues T435 and S473, thereby activating the protein for DNA unwinding activities. In order to substantiate these findings in vivo, we produced NS1 in the presence of a dominant-negative PKClambda mutant and characterized the purified protein in vitro. The NS1 protein produced under these conditions was found to be only partially phosphorylated and as a consequence to be deficient for viral DNA replication. However, it could be rescued for this viral function by treatment with recombinant activated PKClambda. Our data clearly demonstrate that NS1 is a target for PKClambda phosphorylation in vivo and that this modification is essential for the helicase activity of the viral polypeptide. In addition, the phosphorylation of NS1 at residues T435 and S473 appeared to occur mainly in the nucleus, providing further evidence for the involvement of PKClambda which, unlike PKCzeta, accumulates in the nuclear compartment of infected cells
    Type of Publication: Journal article published
    PubMed ID: 12477848
    Signatur Availability
    BibTip Others were also interested in ...
  • 29
    Keywords: ENERGIES ; SPECTRA ; Germany ; human ; IN-VIVO ; VIVO ; SYSTEM ; SYSTEMS ; TISSUE ; ACCURACY ; FREQUENCY ; FIELD ; H-1 ; INVIVO ; SPECTROSCOPY ; FORM ; DIFFERENCE ; ENERGY ; NMR-SPECTROSCOPY ; MUSCLE ; SKELETAL-MUSCLE ; ORIENTATION ; H-1 NMR ; carnosine,in vivo H-1 NMR,human calf muscle,second-order spectra,Breit-Rabi formula ; HUMAN SKELETAL-MUSCLE ; INTRACELLULAR PH ; LACTATE ; ORIGIN ; POSTMORTEM ; PROTON MR SPECTROSCOPY
    Abstract: Spin systems with residual dipolar couplings such as creatine, taurine, and lactate in skeletal muscle tissue exhibit first-order spectra in in vivo H-1 NMR spectroscopy at 1.5 T because the coupled protons are represented by (nearly) symmetrized eigenfunctions. The imidazole ring protons (H2, H4) of carnosine are suspected to form also a coupled system. The ring's stiffness could enable a connectivity between these anisochronous protons with the consequence of second-order spectra at low field strength. Our purpose was to study whether this deviation from the Paschen-Back condition can be used to detect the H2-H4 coupling in localized 1D H-1 NMR spectra obtained at 1.5 T (64 MHz) from the human calf in a conventional whole-body scanner. As for the hydrogen hyperfine interaction, a Breit-Rabi equation was derived to describe the transition from Zeeman to Paschen-Back regime for two dipolar-coupled protons. The ratio of the measurable coupling strength (Sk) and the difference in resonance frequencies of the coupled spins (Deltaomega) induces quantum-state mixing of various degree upon definition of an appropriate eigenbase of the coupled spin system. The corresponding Clebsch-Gordan coefficients manifest in characteristic energy corrections in the Breit-Rabi formula. These additional terms were used to define an asymmetry parameter of the line positions as a function of Sk and Deltaomega. The observed frequency shifts of the resonances were found to be consistent with this parameter within the accuracy achievable in in vivo NMR spectroscopy. Thus it was possible to identify the origin of satellite peaks of H2, H4 and to describe this so far not investigated type of residual dipolar coupling in vivo. (C) 2003 Elsevier Inc. All rights reserved
    Type of Publication: Journal article published
    Signatur Availability
    BibTip Others were also interested in ...
  • 30
    Keywords: APOPTOSIS ; CELLS ; EXPRESSION ; IN-VITRO ; CELL ; Germany ; human ; IN-VIVO ; MODEL ; PATHWAY ; PATHWAYS ; VITRO ; SYSTEM ; DEATH ; DISTINCT ; TIME ; COMPLEX ; COMPLEXES ; primary ; T cell ; T cells ; T-CELL ; T-CELLS ; culture ; activation-induced cell death ; CELL-DEATH ; UP-REGULATION ; CYCLE PROGRESSION ; DISPLAY ; SIGNALING PATHWAY ; SIGNALING PATHWAYS ; B-CELLS ; immune response ; IMMUNE-RESPONSE ; IL-2 ; INITIATION ; FAS-MEDIATED APOPTOSIS ; DISC ; SIGNALING COMPLEX ; ANTIGEN RECEPTOR ; C-FLIPSHORT ; CD95 ; COMPLEX DISC ; FLICE-INHIBITORY PROTEIN ; INTERLEUKIN-2 RECEPTOR
    Abstract: The CD95 (APO-1/Fas) system plays a critical role in activation-induced cell death (AICD) of T cells. We previously described two distinct CD95 (APO-1/Fas) signaling pathways: 1) type I cells show strong death-inducing signaling complex (DISC) formation and mitochondria-independent apoptosis and 2) DISC formation is reduced in type II cells, leading to mitochondria-dependent apoptosis. To investigate the relevance of these pathways, we set up an in vitro model that mimics the initiation and the down phase of an immune response, respectively. Freshly activated human T cells (initiation) are resistant toward CD95-mediated AICD despite high expression of CD95. We previously reported that these T cells show reduced DISC formation. In this study, we show that freshly activated T cells are CD95-type II cells that show high expression levels of Bcl-x(L) and display a block in the mitochondrial apoptosis pathway. Furthermore, we show that, upon prolonged culture (down phase), human T cells undergo a switch from type II to type I cells that renders T cells sensitive to CD95-mediated AICD. Finally, we demonstrate that this switch is dependent on the presence of IL-2. Our observations reveal for the first time that the existence of coexisting CD95 signaling pathways is of physiological relevance
    Type of Publication: Journal article published
    PubMed ID: 12960316
    Signatur Availability
    BibTip Others were also interested in ...
  • 31
    Keywords: measurement ; APOPTOSIS ; CANCER ; CELLS ; EXPRESSION ; GROWTH ; IN-VITRO ; PROTECTION ; tumor ; IN-VIVO ; INHIBITION ; THERAPY ; VIVO ; VOLUME ; DEATH ; liver ; DRUG ; DIFFERENTIATION ; LINES ; TIME ; REDUCTION ; INDUCTION ; RAT ; RATS ; treatment ; ASSAY ; CARCINOMA CELLS ; CELL-DEATH ; SWEDEN ; acetylation ; butyrate ; ALCOHOL ; HISTONE DEACETYLASE ; SODIUM-BUTYRATE ; GREECE ; histone deacetylase inhibitor ; CANCER-THERAPY ; p21(waf1) ; GROWTH ARREST ; HDAC ; Hep3B ; HepT1 ; HUMAN COLON-CANCER ; MAMMARY EPITHELIAL-CELLS ; P53-INDEPENDENT APOPTOSIS ; SP1 SITES ; TRICHOSTATIN-A ; WAF1/CIP1 GENE PROMOTER
    Abstract: 4-Phenylbutyrate (triButyrate(TM), PB) a derivative of the short-chain fatty acid, butyrate, possesses anti-tumor activity in vitro in different tumor cell lines. Unlike most cytostatic compounds, PB possesses low toxicity. In order to evaluate possible clinical use of PB in cancer therapy, hepatocarcinoma (Hep3B) and hepatoblastoma (HepT1) cell lines, as well as xenografts derived from those in nude rats, were treated with PB in different dose (1-100 mM) and time regimens. Treatment with 10 mM of PB for 24 h (or 5 mM for 48 h) was shown to significantly inhibit Hep3B cell growth in vitro. The HepT1 cell line was more sensitive to PB treatment: already 1 mM of PB for 24 h significantly inhibited the growth of the cells. PB also resulted in regression of xenografts derived from these cell lines in vivo, when administrated by mini-pump with an intratumor catheter; yielding 20 mumol of PB per cm(3) of tumor volume per day. TUNEL assay and caspase-3 activity measurements suggested apoptosis to be the cell death mechanism in both cell lines and xenografts. Increased histones H3 and H4 acetylation was shown in both cells and xenografts, and the inhibition of histone deacetylase is proposed as the main trigger for the anti-tumor action of PB. Concomitant induction of p21(WafI/Cip1) expression was detected by RNase protection assay and Western blotting. Reduction in expression of a- fetoprotein was found both in Hep3B cells and xenografts, suggesting also a differentiation effect by PB
    Type of Publication: Journal article published
    PubMed ID: 12579311
    Signatur Availability
    BibTip Others were also interested in ...
  • 32
    Keywords: brain ; RECEPTOR ; CANCER ; CELLS ; EXPRESSION ; tumor ; carcinoma ; CELL ; IN-VIVO ; LUNG-CANCER ; GENE ; GENE-EXPRESSION ; PROTEIN ; PROTEINS ; SAMPLE ; SAMPLES ; EPITHELIA ; TISSUE ; PATIENT ; COMPLEX ; COMPLEXES ; TISSUES ; tumour ; CELL-CYCLE ; CYCLE ; DOWN-REGULATION ; ASSOCIATION ; BREAST ; breast cancer ; BREAST-CANCER ; antibodies ; antibody ; LESIONS ; gene expression ; UP-REGULATION ; BENIGN ; EPITHELIAL-CELLS ; CARCINOMAS ; RT-PCR ; GLANDS ; TERMINAL DIFFERENTIATION ; SECTIONS ; protein expression ; HENSIN ; SALIVARY AGGLUTININ ; MALIGNANT BRAIN-TUMORS ; brain tumor ; SUPPRESSOR GENE ; INTERCALATED CELL ; SURFACTANT PROTEIN-A
    Abstract: Background: We studied the expression of DMBT1 (deleted in malignant brain tumor 1), a putative tumor suppressor gene, in normal, proliferative, and malignant breast epithelium and its possible relation to cell cycle. Methods: Sections from 17 benign lesions and 55 carcinomas were immunostained with anti DMBT1 antibody (DMBTh12) and sections from 36 samples, were double-stained also with anti MCM5, one of the 6 pre-replicative complex proteins with cell proliferation-licensing functions. DMBT1 gene expression at mRNA level was assessed by RT-PCR in frozen tissues samples from 39 patients. Results: Normal glands and hyperplastic epithelium in benign lesions displayed a luminal polarized DMBTh12 immunoreactivity. Normal and hyperplastic epithelium adjacent to carcinomas showed a loss of polarization, with immunostaining present in basal and perinuclear cytoplasmic compartments. DMBT1 protein expression was down-regulated in the cancerous lesions compared to the normal and/or hyperplastic epithelium adjacent to carcinomas (3/55 positive carcinomas versus 33/42 positive normal/hyperplastic epithelia; p=0.0001). In 72% of cases RT-PCR confirmed immunohistochemical results. Most of normal and hyperplastic mammary cells positive with DMBTh12 were also MCM5-positive. Conclusions: The redistribution and up-regulation of DMBT1 in normal and hyperplastic tissues flanking malignant tumours and its down-regulation in carcinomas suggests a potential role in breast cancer. Moreover, the concomitant expression of DMTB1 and MCM5 suggests its possible association with the cell-cycle regulation
    Type of Publication: Journal article published
    PubMed ID: 15301691
    Signatur Availability
    BibTip Others were also interested in ...
  • 33
    Keywords: RECEPTOR ; CANCER CELLS ; CELLS ; EXPRESSION ; GROWTH ; tumor ; carcinoma ; CELL ; Germany ; human ; IN-VIVO ; KINASE ; MODEL ; PATHWAY ; CDNA ; CLONES ; GENE ; PROTEIN ; transcription ; ACTIVATION ; LIGAND ; MECHANISM ; FAMILY ; TRANSCRIPTION FACTOR ; AP-1 ; BINDING ; BIOLOGY ; C-JUN ; MEMBER ; MEMBERS ; MOLECULAR-BIOLOGY ; PHOSPHORYLATION ; protein kinase ; PROTEIN-KINASE ; ACID ; GROWTH-INHIBITION ; CARCINOMA-CELLS ; BETA ; Jun ; DEGRADATION ; HeLa cells ; DIMERIZATION ; AFFINITY ; MEDIATED REPRESSION ; N-TERMINAL KINASE ; CONSTITUTIVE EXPRESSION ; CROSS-TALK ; FACTOR-ALPHA ; F ; molecular biology ; ACTIVATED PROTEIN-KINASES ; ALL-TRANS ; cervical carcinoma cells ; HELA-CELLS ; PROTEASOME INHIBITORS ; X-RECEPTOR
    Abstract: Expression of the nuclear retinoic acid receptor beta2 (RARbeta2) gene is often disturbed in cervical carcinoma cells. One important mechanism by which RARbeta2 can exert growth inhibitory function is based on its ability to repress the AP-1 transcription factor in a ligand-dependent manner. Because less is known about the biological effects of RARbeta in the absence of ligand, the corresponding cDNA was stably introduced into HPV18-positive HeLa cervical carcinoma cells. In the present study we describe a novel mechanism by which AP-1 becomes inactivated. Constitutive expression of nonliganded RARbeta abrogated both AP-1 binding affinity and activity by a selective degradation of the c-Jun protein as major dimerization partner, without substitution by other members of the Jun family. Blockage of the proteasomal pathway completely rescued c-Jun and reconstituted the AP-1 function. Moreover, HeLa RARbeta2 clones treated either with tumor necrosis factor-alpha or transfected with a constitutive active upstream mitogen-activated protein kinase (MEKK1Delta) also resulted in c-Jun phosphorylation and restoration of AP-1 affinity and functionality similar to that found in nontransfected parental HeLa cells. These data revealed an important cross-talk between trans-repression of AP-1 and nonliganded RARbeta in human papillomavirus-positive cells. Because AP-1 activity was not irreversibly disturbed, but could be switched on through activation of the Jun N-terminal kinase pathway, a model for the transient activation of AP-1 even in the presence of RARbeta as repressor is suggested
    Type of Publication: Journal article published
    PubMed ID: 15308638
    Signatur Availability
    BibTip Others were also interested in ...
  • 34
    Keywords: ENVIRONMENT ; ANGIOGENESIS ; CANCER ; CELLS ; tumor ; CELL ; Germany ; human ; IN-VIVO ; MODEL ; MODELS ; THERAPY ; GENERATION ; DISTINCT ; PATIENT ; RESPONSES ; INDUCTION ; ANTIGEN ; ANTIGENS ; DENDRITIC CELLS ; LYMPH-NODES ; treatment ; tumor antigens ; MOUSE ; MALIGNANCIES ; resistance ; CANCER-PATIENTS ; IMMUNITY ; IMMUNOTHERAPY ; MOUSE MODEL ; REJECTION ; DE-NOVO ; CANCER PATIENTS ; CANCER-THERAPY ; EFFECTOR ; cancer therapy ; SOLID TUMORS ; T-CELL-ACTIVATION ; ANTIGENIC CANCER-CELLS ; ANTITUMOR LYMPHOCYTES ; EFFECTOR FUNCTION ; immune therapy ; transgenic tumor models ; TUMOR-ANTIGENS
    Abstract: In immunological cancer therapy, the current treatment emphasis is on the generation of effector cells that are specific for tumor antigens. However, there is a distressing lack of correlation between the induction of specific immunity in cancer patients and measurable clinical benefit. By studying mouse models of de novo tumongenesis we are beginning to understand that the tumor itself, in particular the manifestation of a distinct tumor environment, impairs immune effector function; this concept is yet to be applied in human malignancy
    Type of Publication: Journal article published
    PubMed ID: 15368278
    Signatur Availability
    BibTip Others were also interested in ...
  • 35
    Keywords: CELLS ; tumor ; carcinoma ; CELL ; COMBINATION ; Germany ; IN-VIVO ; MODEL ; THERAPY ; VIVO ; MOLECULES ; TISSUE ; TUMORS ; MICE ; ACTIVATION ; DNA ; OLIGODEOXYNUCLEOTIDES ; T cell ; T cells ; T-CELL ; T-CELLS ; TOLERANCE ; treatment ; MOLECULE ; MOUSE ; UP-REGULATION ; EFFICACY ; ADHESION ; CARCINOMAS ; STRATEGIES ; CD8(+) ; IMMUNE-RESPONSE ; vaccination ; MOUSE MODEL ; REJECTION ; DE-NOVO ; ADJUVANT ; EFFECTOR ; CROSS-PRESENTATION ; AGENT ; CELL CARCINOMA ; INFILTRATION ; T-CELL-ACTIVATION ; ANTIGEN-TRANSGENIC MICE ; ESTABLISHED TUMORS ; INDUCE REJECTION
    Abstract: In a transgenic mouse model expressing SV40 T Ag (Tag) as a de novo tumor Ag, immune surveillance fails and islet cell carcinomas grow progressively. To develop an anticancer strategy that would be effective in eradicating solid, autochthonously growing tumors, we evaluated the effectiveness of immunostimulatory oligodeoxynucleotides (ODN) with cytosine-guanine-rich (CpG) motifs (CpG-ODN). In a classical vaccination protocol, Tag was administered with CpG-ODN as adjuvant. The antitumor vaccination, however, was only effective in a prophylactic setting, despite the successful activation of a Tag-specific CTL response in vivo. Histological examination demonstrated that even primed immune cells failed to infiltrate tumors once a malignant environment was established. To ensure that effector cells were not limiting, highly activated tumor Ag-specific T cells were transferred into tumor-bearing mice. However, this treatment also failed to result in tumor infiltration and rejection. Therefore, we further tested the efficacy of CpG-ODN as a proinflammatory agent in combination with the transfer of preactivated Tag-specific CD4(+) and CD8(+) T cells. Indeed, this combination therapy p. roved to be highly effective, because CpG-ODN rendered insulinomas permissive for massive infiltration and destruction. The opening of tumor