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Results 401 - 450 of 1495
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Di Fulvio Mauricio - - 2007
Grb2 is an SH2-SH3 protein adaptor responsible for linking growth factor receptors with intracellular signaling cascades. To study the role of Grb2 in cell growth, we have generated a new COS7 cell line (COS7(shGrb2)), based on RNAi technology, as null mutations in mammalian Grb2 genes are lethal in early development. ...
Phanstiel O O - - 2007
A series of polyamine conjugates were synthesized and evaluated for their ability to target the polyamine transporter (PAT) in two Chinese hamster ovary (CHO) cell lines (PAT-active CHO and PAT-inactive CHOMG). This systematic study identified salient features of the polyamine architecture required to target and enter cells via the PAT. ...
Mitchell J L A - - 2007
One strategy for inhibiting tumour cell growth is the use of polyamine mimetics to depress endogenous polyamine levels and, ideally, obstruct critical polyamine-requiring reactions. Such polyamine analogues make very unusual drugs, in that extremely high intracellular concentrations are required for growth inhibition or cytotoxicity. Cells exposed to even sub-micromolar concentrations ...
Oredsson S M - - 2007
Reduction of cellular polyamine pools results in inhibition of cell proliferation and sometimes in induction of cell death. Reduction of cellular polyamine pools can be achieved by several strategies involving all the mechanisms of polyamine homoeostasis, i.e. biosynthesis, catabolism and transport across the cell membrane. In the present paper, we ...
Yehudai-Resheff Shlomit - - 2007
Cell survival depends on the cell's ability to acclimate to phosphorus (P) limitation. We studied the chloroplast ribonuclease polynucleotide phosphorylase (PNPase), which consumes and generates phosphate, by comparing wild-type Chlamydomonas reinhardtii cells with strains with reduced PNPase expression. In the wild type, chloroplast RNA (cpRNA) accumulates under P limitation, correlating ...
Werbrouck Hadewig - - 2007
In the current study, various steps in the real-time reverse transcription PCR (real-time RT-PCR) method for determination of RNA expression levels starting from different numbers of Listeria monocytogenes cells were evaluated and optimized. Our results showed that the RNA isolation method as well as the cDNA synthesis may influence the ...
Abe Ken-ichi - - 2007
We recently established a genome-length HCV RNA-replicating cell line (O strain of genotype 1b; here called O cells) using cured cells derived from sO cells, in which HCV subgenomic replicon RNA with an adaptive NS5A mutation (S2200R) is replicated. Characterization of the O cells revealed a second adaptive NS3 mutation ...
Armakolas Athanasios - - 2007
During cell division, copies of mouse chromosome 7 are segregated selectively or randomly to daughter cells depending on the cell type. The mechanism for differential segregation is unknown. Because mouse left-right dynein (LRD) gene mutations result in randomization of visceral organs' laterality, we hypothesized that LRD may also function in ...
Danielsson, Louise
RNA interference is a naturally occurring process of gene silencing that reduces the expression of the gene from which the RNA sequence is derived, when added in a double-stranded form. RNA interference works as defense against viruses and transposons. The aim of this study was to optimize a protocol for ...
Bullinger Dino - - 2007
BACKGROUND: Cancer, like other diseases accompanied by strong metabolic disorders, shows characteristic effects on cell turnover rate, activity of modifying enzymes and DNA/RNA modifications, resulting also in elevated amounts of excreted modified nucleosides. For a better understanding of the impaired RNA metabolism in breast cancer cells, we screened these metabolites ...
Khodosevich Konstantin - - 2007
BACKGROUND: The analysis of gene expression for tissue homogenates is of limited value because of the considerable cell heterogeneity in tissues. However, several methods are available to isolate a cell type of interest from a complex tissue, the most reliable one being Laser Microdissection (LMD). Cells may be distinguished by ...
Deshayes Sébastien - - 2007
Control of gene expression using RNA interference (RNAi) technology constitutes a method of choice for investigating gene function in mammalian cells. However, like most oligonucleotide-based strategies, the major limitation of interfering RNA is their poor cellular uptake due to low permeability of the cell membrane to nucleic acids. Several strategies ...
Tschaharganeh Darjus - - 2007
Elimination of protein expression using RNA interference (RNAi) significantly improves the understanding of gene function and represents a promising technique for the treatment of diseases such as cancer and neurological disorders. Accumulating evidence suggests the so-called interferon-independent non-specific gene silencing of short interfering RNA (siRNA); however, its biological and functional ...
Kaneko Shiho - - 2007
PURPOSE: A prior study showed inactivation of ornithine-delta-aminotransferase (OAT)-deficient human retinal pigment epithelial (RPE) cells by a specific irreversible inhibitor (5-fluoromethylornithine; 5-FMO) leading to cell death, in an in vitro model of gyrate atrophy (GA) of the choroid and retina. In the present study, the cytotoxicity of metabolites of ornithine, ...
Alkhabuli Juma O - - 2007
Neo-angiogenesis is an essential process in physiological and pathological conditions. However, it is a complex process. Several studies demonstrated that intra-tumoural microvessel number is a significant predictor of metastasis and clinical outcome in many tumours, including oral malignancies. The immuno-surveillance cells, mast cells and eosinophils are implicated in the biological ...
Bernstein Kara A - - 2007
In the yeast Saccharomyces cerevisiae it has long been thought that cells must reach a critical cell size, called the "setpoint," in order to allow the Start cell cycle transition. Recent evidence suggests that this setpoint is lowered when ribosome biogenesis is slowed. Here we present evidence that yeast can ...
Roussi Stamatiki - - 2006
7beta-OHsitosterol and 7beta-OHcholesterol are natural compounds of plant and animal cells with high structural similarity. Recently it was reported that both compounds induced apoptosis on human colon cancer cells by targeting different signalling pathways. Our study aimed at comparing their effects on polyamine metabolism and its relation to apoptosis. When ...
Cram Erin J - - 2006
Cell migration is essential during embryonic development and tissue morphogenesis. During gonadogenesis in the nematode Caenorhabditis elegans, migration of the distal tip cells forms two U-shaped gonad arms. Malformation results if the distal tip cells stop prematurely or follow an aberrant path, and abnormalities are easily visualized in living nematodes. ...
Dormoy-Raclet V - - 2007
Unr (upstream of N-ras) is a cytoplasmic RNA-binding protein involved in the regulation of messenger RNA stability and internal initiation of translation. We have used Unr-deficient murine embryonic stem (ES) cells to analyse Unr role in cell proliferation and response to stress. Disruption of both unr gene copies had no ...
Coburn Ronald F - - 2006
Spermine (SPM) and spermidine (SPD) activate isolated phosphatidylinositol-4-phosphate 5-kinases (PI(4)P5K), enzymes that convert phosphatidylinositol-4-phosphate to phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). PI(4,5)P2 formation is known to be involved in cellular actin reorganization and motility, functions that are also influenced by polyamines. It has not been proven that endogenous polyamines can control inositol phospholipid ...
Wolf C - - 2007
The aim of the present study was to challenge potential mechanisms of action underlying the inhibition of tumor cell proliferation by agmatine. Agmatine inhibited proliferation of the human hepatoma cells HepG2, the human adenocarcinoma cells HT29, the rat hepatoma cells McRH7777, and the rat pheochromocytoma cells PC-12. Inhibition of proliferation ...
Cai Suqin - - 2006
Laser capture microdissection and related technologies permit the harvest of individual cells and cell types. Isolation of either nucleic acids or proteins from laser-captured cells supports such downstream applications as the construction of cell-specific cDNA libraries and the profiling of expressed genes and proteins. The success of these endeavors is ...
Li Qing-hua - - 2006
BACKGROUND: Sam68 plays an important role as a multiple functional RNA binding nuclear protein in cell cycle progress, RNA usage, signal transduction, and tyrosine phosphorylation by Src during mitosis. However, its precise impact on these essential cellular functions remains unclear. The purpose of this study is to further elucidate Sam68 ...
Ngantung Frederyk A - - 2006
An important challenge facing therapeutic protein production in mammalian cell culture is the cleavage of terminal sialic acids on recombinant protein glycans by the glycosidase enzymes released by lysed cells into the supernatant. This undesired phenomenon results in a protein product which is rapidly cleared from the plasma by asialoglycoprotein ...
Morozkin Evgeniy S - - 2006
Kinetics of extracellular RNA accumulation in culture medium and at the cell surface along with their composition and distribution among cell-free and cell-surface-bound fractions were investigated in mycoplasma-contaminated and mycoplasma-free HeLa cells. It was shown that the mycoplasma infection influenced the concentration and kinetics of accumulation of total extracellular RNA ...
Kasama Takashi - - 2006
We report here a functional analysis of spo5(+)(mug12(+)) of Schizosaccharomyces pombe, which encodes a putative RNA-binding protein. The disruption of spo5(+) caused abnormal sporulation, generating inviable spores due to failed forespore membrane formation and the absence of a spore wall, as determined by electron microscopy. Spo5 regulates the progression of ...
Sakai Tokiko - - 2006
Amyloid precursor protein (APP) and amyloid precursor-like proteins 1 and 2 (APLP1 and APLP2) are members of a large gene family. Although APP is known to be the source of the beta-amyloid peptides involved in the development of Alzheimer's disease, the normal functions of APP, APLP1 and APLP2 in cells ...
Merrill Melinda K - - 2006
Poliovirus (PV) plus-strand RNA genomes initiate translation in a cap-independent manner via an internal ribosome entry site (IRES) in their 5' untranslated region. Viral translation is codetermined by cellular IRES trans-acting factors, which can influence viral propagation in a cell-type-specific manner. Engineering of a poliovirus recombinant devoid of neuropathogenic properties ...
Huang Ke-Jung - - 2006
Our earlier studies had suggested that endonuclease G (EndoG), a member of the evolutionarily conserved DNA/RNA nonspecific betabetaalpha-Me-finger nuclease family, functioned in the a sequence-mediated segment inversion observed during herpes simplex virus 1 replication. To test this hypothesis, we used RNA interference to reduce the level of EndoG in mammalian ...
Li Qian - - 2006
The higher-order structural organization of the cell nucleus reflects the underlying genome-wide transcriptional activity and macromolecular transport processes. To study the microscopic organization of RNA distribution within the nucleus, a combinatorial library of fluorescent styryl molecules was synthesized and screened for an in vitro RNA response and live cell nuclear ...
Lents Nathan H NH Department of Pathology, NYU Medical Center, New York, New York, USA. - - 2006
In a new study, a systematic screen for genes necessary for normal cell cycle progression has been completed in Drosophila S2 cells. some familiar faces and some new faces add to our appreciation of the staggering complexity of cellular growth and proliferation. The apparent utility of genome-wide RNA interference screens ...
Wu Meiqun - - 2006
Calpains are a family of calcium-dependent cysteine proteases involved in a variety of cellular functions. Two isoforms, m-calpain and mu-calpain, have been implicated in cell migration. However, since conventional inhibitors used for the studies of the functions of these enzymes lack specificity, the individual physiological function and biochemical mechanism of ...
Culley David E - - 2006
The recent completion of a draft genome sequence for Methanosarcina barkeri has allowed the application of various high throughput post-genomics technologies, such as nucleic acid microarrays and mass spectrometry of proteins to detect global changes in transcription and translation that occur in response to experimental treatments. However, due to the ...
Pramoonjago P - - 2006
Microarray RNA gene expression profiling analysis has shown that Sox4 (Sry-related high mobility group (HMG) box 4) is one of the most upregulated genes in adenoid cystic carcinoma (ACC), relative to non-neoplastic tissue of origin. Here, we show that Sox4 protein is similarly upregulated in ACC by immunohistochemistry of 28 ...
Gill Tina - - 2006
RNase mitochondrial RNA processing (MRP) is an essential ribonucleoprotein endoribonuclease that functions in the degradation of specific mRNAs involved in cell cycle regulation. We have investigated where this processing event occurs and how it is regulated. As expected, results demonstrate that RNase MRP is predominantly localized in the nucleolus, where ...
Smetana K - - 2006
Human myeloblasts were studied in bone marrow of patients suffering from chronic phase of chronic myeloid leukaemia to provide more information on the nucleolar diameter in these early granulocytic progenitors. These cells are a convenient model for such study since the number of myeloblasts in diagnostic bone marrow smears of ...
Merrill Melinda K - - 2006
Translation of picornavirus plus-strand RNA genomes occurs via internal ribosomal entry at highly structured 5' untranslated regions. In addition to canonical translation factors, translation rate is likely influenced by supplementary host and viral trans-acting factors. We previously reported that insertion of a heterologous human rhinovirus type 2 internal ribosomal entry ...
Wakiyama Motoaki - - 2006
RNA interference (RNAi) is a fundamental mechanism of gene regulation in a variety of organisms. In Drosophila cells, long double-stranded RNAs (dsRNAs) are processed into 21- to 23-nucleotide double-stranded fragments, termed short interfering RNAs (siRNAs). The siRNAs trigger sequence-specific mRNA degradation, which results in the inhibition of gene expression. These ...
Ulvila Johanna - - 2006
Double-stranded RNA (dsRNA) fragments are readily internalized and processed by Drosophila S2 cells, making these cells a widely used tool for the analysis of gene function by gene silencing through RNA interference (RNAi). The underlying mechanisms are insufficiently understood. To identify components of the RNAi pathway in S2 cells, we ...
Vanisree A J - - 2006
Ornithine decarboxylase (ODC) is a marker of lung cancer and is a key enzyme in the synthesis of polyamines, which are necessary for the promotion of the growth of malignant cells. This study assesses the dose-dependent effect of N-acetylcysteine (NAC), a chemopreventive agent, in combination with vitamin C (VC) on ...
Zhang Bing - - 2006
AIM: To construct a recombinant adenovirus that can simultaneously express both antisense ornithine decarboxylase (ODC) and adenosylmethionine decarboxylase ( AdoMetDC ) and detect its inhibitory effect on the intracellular polyamine pool and colorectal cancer cell growth. METHODS: A 205-bp cDNA of AdoMetDC was reverse-inserted into recombinant pAdTrack-ODCas vectors and recombined ...
Navarro Beatriz - - 2006
The replicase proteins p33 and p92 of Cymbidium ringspot virus (CymRSV) were found to support the replication of defective interfering (DI) RNA in Saccharomyces cerevisiae cells. Two yeast strains were used, differing in the biogenesis of peroxisomes, the organelles supplying the membranous vesicular environment in which CymRSV RNA replication takes ...
Yuan Jing - - 2006
Changes in Epstein-Barr virus (EBV) and cell RNA levels were assayed following immunoglobulin G (IgG) cross-linking-induced replication in latency 1-infected Akata Burkitt B lymphoblasts. EBV replication as assayed by membrane gp350 expression was approximately 5% before IgG cross-linking and increased to more than 50% 48 h after induction. Seventy-two hours ...
Jeong Dae-won - - 2006
In order to conduct a physiological functional study of lactate dehydrogenase (LDH) and glycerol-3-phosphate dehydrogenase (GPDH), we engineered a CHO dhfr(-) cell, by overexpressing either the anti-sense LDH-A RNA (anti-LDH cells) or GPDH (GP3 cells), or both (GP3/anti-LDH cells). LDH activity in the cell cytosol, and lactate content and pHe ...
Chan David Wai - - 2006
Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC) in Southeast Asia and Hong Kong. Among the four proteins that are encoded by the HBV genome, HBV X (HBx) is the most potentially oncogenic factor. It is known that HBx plays an important role in hepatocarcinogenesis, ...
Maeda Tomoji - - 2006
L-Arginine is a precursor of polyamine, nitric oxide (NO), creatine, and agmatine and is essential for the differentiation and proliferation of blood cells, although the precise biological role of L-arginine is unclear. We have recently reported that the depletion of L-arginine in cultured medium prevented both proliferation and differentiation of ...
Kun Ernest - - 2006
Treatment of cells with lysophosphatidyl choline and centrifugal extraction can separate poly (ADP-ribose) synthetase (PARP-1) and DNA synthetase activities, permitting the experimental analysis and comparison of both multienzyme systems. Only PARP-1 is being assayed by our system. Ca(2+) and Mg(2+) have minor activating effects, and added histones are without activating ...
Minchin Rodney F - - 2006
N1, N11-diethylnorspermine (DENSPM) is a polyamine analog that is currently under investigation as a novel anticancer drug. Although it has shown promising preclinical activity, there has been large variation in responsiveness reported between different human cancers. During our studies into the causes of this variation, we observed a consistent increase ...
Persson, Lo
It has become increasingly obvious during the last two decades that a multitude of cellular processes are highly dependent on adequate levels of polyamines (1–6). Too high concentrations of the polyamines are toxic to the cell and may induce cell death or apoptosis (7). On the other hand, too low ...
Cully Megan J - - 2006
Cell-based genome-wide RNA interference screens are being used to address an increasingly broad spectrum of biological questions. In one recent screen, Drosophila cell cultures treated with double-stranded RNA were analyzed by flow cytometry, providing a wealth of new information and identifying 488 regulators of the cell cycle, cell size, and ...
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