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Nonaka Mizuho - - 2009
The human immunodeficiency virus type 1 (HIV-1) accessory protein Vpr induces apoptosis after cell cycle arrest at the G2 phase in primate cells. We have reported previously that C81, a carboxy-terminally truncated form of Vpr, interferes with cell proliferation and results in apoptosis without G2 arrest. Here, we investigated whether ...
Smith Terry K - - 2009
The African trypanosome Trypanosoma brucei is covered with a dense layer of Variant Surface Glycoprotein (VSG), which protects it from lysis by host complement via the alternative pathway in the mammalian bloodstream. Blocking VSG synthesis by the induction of VSG RNAi triggers an unusually precise precytokinesis cell-cycle arrest. Here, we ...
Veses Veronica - - 2009
Hyphal growth of Candida albicans is characterized by asymmetric cell divisions in which the subapical mother cell inherits most of the vacuolar space and becomes cell cycle arrested in G1, while the apical daughter cell acquires most of the cell cytoplasm and progresses through G1 into the next mitotic cell ...
Wang Yangming - - 2008
Dgcr8 knockout embryonic stem (ES) cells lack microprocessor activity and hence all canonical microRNAs (miRNAs). These cells proliferate slowly and accumulate in G1 phase of the cell cycle. Here, by screening a comprehensive library of individual miRNAs in the background of the Dgcr8 knockout ES cells, we report that multiple ...
Wu Wenqi - - 2008
In higher eukaryotes DNA double-strand breaks (DSBs) are repaired by homologous recombination repair (HRR) or nonhomologous end joining (NHEJ). In addition to the DNA-PK dependent pathway of NHEJ (D-NHEJ), cells employ a backup pathway (B-NHEJ) using DNA ligase III and PARP1. We have reported previously that mouse embryo fibroblasts (MEFs) ...
Nimbalkar Dipali - - 2008
DNA damage activates arrest checkpoints to halt cell cycle progression in G(1) and G(2) phases. These checkpoints can be overridden in hematopoietic cells by cytokines, such as erythropoietin, through the activation of a phosphoinositide 3-kinase (PI3K) signaling pathway. Here, we show that PI3K activity specifically overrides delayed mechanisms effecting permanent ...
Mao Zhiyong - - 2008
DNA double-strand breaks (DSBs) are dangerous lesions that can lead to potentially oncogenic genomic rearrangements or cell death. The two major pathways for repair of DSBs are nonhomologous end joining (NHEJ) and homologous recombination (HR). NHEJ is an intrinsically error-prone pathway while HR results in accurate repair. To understand the ...
Stifanese Roberto - - 2008
In dividing cells calpastatin diffuses from aggregates into cytosol, indicating the requirement for a tight regulation of calpain. Accordingly, the involvement of the calpain-calpastatin system in cell proliferation and in the density-dependent growth arrest was studied in JA3 cells stably transfected with a calpastatin form permanently localized in cytosol. In ...
Sitko John C - - 2008
Genotoxic agents such as ionizing radiation trigger cell cycle arrest at the G1/S and G2/M checkpoints, allowing cells to repair damaged DNA before entry into mitosis. DNA damage-induced G1 arrest involves p53-dependent expression of p21 (Cip1/Waf-1), which inhibits cyclin-dependent kinases and blocks S phase entry. While much of the core ...
Kamohara Yukio - - 2008
BACKGROUND: Recent evidence suggests that some solid cancers originate from cancer stem cells. We have identified a subset of candidate stem cells, which are termed side population (SP) cells, in the hepatocellular carcinoma cell line Huh7. Because most stem cells reside in the G0 phase of the cell cycle, G0 ...
Didier Christine - - 2008
Polo-Kinase 1 (PLK1) is a key cell cycle regulator that is necessary for checkpoint recovery after DNA damage-induced G2 arrest. We have examined the effects of PLK inhibition in Acute Myelocytic Leukaemia (AML) cells, whose resistance to genotoxic agents is thought to be associated with checkpoint reinforcement. We report that ...
Fortin Jessica S - - 2008
Recently, a subset of N-phenyl-N'-(2-chloroethyl)ureas (CEU) was found abrogating the nuclear translocation of thioredoxin-1 and arresting the cell cycle in G(0)/G(1) phase. Several derivatives were prepared to assess their effect on cell cycle progression and on the intracellular location of Trx-1. Compounds 1-20, 21-40, and 41-60 exhibited GI(50) between 1 ...
Minnhagen Susanna - - 2008
Kleptoplasty is the retention of plastids obtained from ingested algal prey, which can remain temporarily functional and be used for photosynthesis by the predator. With a new approach based on cell cycle analysis, we have addressed the question of whether the toxic, bloom-forming dinoflagellate Dinophysis norvegica practice kleptoplasty or if ...
Javanmoghadam-Kamrani Sonia - - 2008
Synchronization by Lovastatin arrests many cell types reversibly in the G(1) phase of the cell cycle. Here we show that Lovastatin (10 microM) mediates cell cycle arrest in human breast cancer cells, MCF-7 and MDA-MB-231, where 85% of cells accumulate in the G(1) phase of the cell cycle. Addition of ...
Demidenko Z N - - 2008
Paclitaxel (PTX) and other microtubule inhibitors cause mitotic arrest. However, low concentrations of PTX (low PTX) paradoxically cause G1 arrest (without mitotic arrest). Here, we demonstrated that unexpectedly, low PTX did not cause G1 arrest in the first cell cycle and did not prevent cells from passing through S phase ...
Michaelson David D Department of Medicine, New York University School of Medicine, New York, NY 10016, - - 2008
Rac1 regulates a wide variety of cellular processes. The polybasic region of the Rac1 C terminus functions both as a plasma membrane-targeting motif and a nuclear localization sequence (NLS). We show that a triproline N-terminal to the polybasic region contributes to the NLS, which is cryptic in the sense that ...
Durcan Thomas M - - 2008
Centrosome duplication must remain coordinated with cell cycle progression to ensure the formation of a strictly bipolar mitotic spindle, but the mechanisms that regulate this coordination are poorly understood. Previous work has shown that prolonged S-phase is permissive for centrosome duplication, but prolonging either G2 or M-phase cannot support duplication. ...
Muramoto Tetsuya T Division of Cell and Developmental Biology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, - - 2008
The regulation of the Dictyostelium cell cycle has remained ambiguous owing to difficulties in long-term imaging of motile cells and a lack of markers for defining cell cycle phases. There is controversy over whether cells replicate their DNA during development, and whether spores are in G1 or G2 of the ...
Kamida Akitoshi - - 2008
PURPOSE: The effects of boronophenylalanine (BPA)-mediated boron neutron capture therapy (BNCT) on the growth potential and cell cycle of human oral squamous cell carcinoma (SCC) cells were examined. MATERIALS AND METHODS: SAS cells expressing a functional wild-type p53 were exposed to neutron beams in the presence of BPA and growth ...
Lee In Jeong - - 2008
Interleukin (IL)-5 plays an important role in the progression of allergic inflammation. Here, we have isolated 21alpha-methylmelianodiol and 21beta-methylmelianodiol from Poncirus trifoliata (L.) Raf., a plant of the Rutaceae family, as the inhibitors of IL-5-dependent growth of Y16 pro-B cells by bioassay-guided fractionation. 21alpha-Methylmelianodiol and 21beta-methylmelianodiol inhibited IL-5-dependent growth of ...
Hu Xiao Tang - - 2008
TGFbeta is well known for its inhibitory effect on cell cycle G1 checkpoint kinases. However, its role in the control of pRb-E2F complexes is not well established. TGFbeta inhibits phosphorylation of pRb at several serine and threonine residues and regulates the association of E2F transcription factors with pRb family proteins. ...
Shin Jae-Sik - - 2008
Recent studies have suggested that Skp2, an SCF-type ubiquitin ligase, positively regulates cell cycle through degradation of p27, which is an inhibitor of cyclin-dependent kinase 2 (CDK2), which drives cells from the G1 to S phase of cell cycles. In the present study, we examined key regulatory proteins involved in ...
Pothiratana Chetsada
Ustilago maydis is a phytopathogenic basidiomycete infecting corn plants. Pathogenic development is initiated via a pheromone/receptor-based system encoded by the a-mating type locus. Upon pheromone stimulation, two compatible haploid sporidia form conjugation hyphae that are cell cycle arrested in the G2 phase. Upon fusion of the conjugation tubes, a dikaryotic ...
Banfalvi Gaspar - - 2008
Synchronization of cells and nuclei is a powerful technique for the exact study of regulatory mechanisms and for understanding cell cycle events. Counterflow centrifugal elutriation is a biophysical cell separation technique in which cell size and sedimentation density differences of living cells are exploited to isolate subpopulations in various stages ...
Ueda Akiko - - 2008
BACKGROUND: Polyamines and ornithine decarboxylase (ODC) are essential for cell proliferation. DL-alpha-difluoromethylornithine (DFMO), a synthetic inhibitor of ODC, induces G1 arrest through dephosphorylation of retinoblastoma protein (pRb). The effect of DFMO on cell growth of pRb deficient cells is not known. We examined the effects of DFMO on pRb deficient ...
Stan Silvia D - - 2008
Withaferin A (WA) is derived from the medicinal plant Withania somnifera that has been safely used for centuries in the Indian Ayurvedic medicine for treatment of various ailments. We now demonstrate that WA treatment causes G2 and mitotic arrest in human breast cancer cells. Treatment of MDA-MB-231 (estrogen-independent) and MCF-7 ...
Chowdhury Arnab Roy - - 2008
Procyclic Trypanosoma brucei cells were synchronized with 0.2 mM hydroxyurea. The cells did not arrest at the G(1)/S boundary but proceeded through one round of replication and arrested near the end of S phase. The mitochondrial genome (kinetoplast DNA network) replicated, forming two progeny networks, but the repair of minicircle ...
Hirano Hiroto - - 2008
Although sucrose availability is crucial for commitment to plant cell division during G1 phase by controlling the expression of D-type cyclins, it has remained unclear how these factors mediate entry into the cell cycle. Here we show that Arabidopsis RETINOBLASTOMA-RELATED PROTEIN 1 (AtRBR1) is involved in G1-phase cell cycle arrest ...
Tavecchio M - - 2007
OBJECTIVES: Trabectedin (ET-743, Yondelis) is a natural marine product, with antitumour activity, currently in phase II/III clinical trials. Previous studies have shown that cells hypersensitive to ultraviolet (UV)-rays because of nucleotide excision repair (NER) deficiency, were resistant to trabectedin. The purpose of this study was to investigate whether this resistance ...
Blomen V A - - 2007
During the cell cycle, a cell may encounter one of five different fates: it can proliferate, differentiate, become quiescent or senescent, or go into apoptosis. The initiation of such fates is often seen in the G1 phase. The aim of this review is to describe an integrative model of G1 ...
Brunet Julie - - 2008
Toxoplasma gondii is an obligate intracellular parasite that causes severe disease in humans. It is able to infect all nucleated mammalian cells leading to lifelong persistence of the parasite in the host. Here, we studied the effect of T. gondii infection on host cell proliferation and explored the molecular mechanisms ...
Caro Elena - - 2007
The transition of precursor cells from an undifferentiated proliferative state to differentiated cells with specific fates is of primary importance for multicellular organisms. Animals and plants have evolved two unrelated proteins, geminin and GEM, respectively, that play analogous roles in regulating this transition. These proteins are involved, probably in early ...
Iborra Francisco J FJ MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Oxford, OX3 9DS, UK. - - 2008
Wide-confocal-cytometry (WCC) is a new method developed in this paper that uses a standard confocal system to gather quantitative information on contents and fine structural details of cells. The system is operated under conditions of non-confocality, in order to capture the maximum amount of light emitted by the specimen (comparable ...
Du Kejun - - 2008
Lipopolysaccharide (LPS) is the toxic determinant for Gram-negative bacterium infection. The individual response to LPS was related to its gene background. It is necessary to identify new molecules and signaling transduction pathways about LPS. The present study was undertaken to evaluate the effects of a novel environmental lipopolysaccharide-responding (Elrg) gene ...
Hahm Eunsil - - 2007
Vitamin C has inconsistent effects on malignant tumor cells, which vary from growth stimulation to apoptosis induction. It is well known that melanoma cells are more susceptible to vitamin C than any other tumor cells, but the precise mechanism remains to be elucidated. In the present study, the proliferation of ...
Nowrouzi Azin - - 2007
BACKGROUND: Dendrostellera lessertii (Thymelaeaceae) is a toxic plant that grows in parts of Iran. The anti-proliferative properties of its crude methanol extract and one of its active components, 3-hydrogenkwadaphnin (3-HK), have been established using several cancer cell lines. METHODS: In a further attempt to determine the mode of action, two ...
Cecchi Cristina - - 2008
A key role of mitotic activation in neuronal cell death in early stages of Alzheimer's disease (AD) has been suggested. Apparently, terminally differentiated neurons are precluded from mitotic division, yet some phenotypic markers of cell cycling are present in AD-vulnerable brain areas. In this paper, we investigated whether dividing human ...
Conde de Felipe Magnolia M - - 2008
Successful completion of the Toxoplasma cell cycle requires the coordination of a series of complex and ordered processes that results in the formation of two daughters by internal budding. Although we now understand the order and timing of intracellular events associated with the parasite cell cycle, the molecular details of ...
Lu Mei - - 2008
Cell kinetics employed for embryonic models was modified and used to study the neuronogenesis in the subventricular zone (SVZ) in adult rats subjected to stroke. Enhanced analytical approaches were introduced and used to compare the cell cycle length (T(C)) and length in G(1) phase, T(G1), at various times after stroke ...
Di Talia Stefano - - 2007
Molecular noise in gene expression can generate substantial variability in protein concentration. However, its effect on the precision of a natural eukaryotic circuit such as the control of cell cycle remains unclear. We use single-cell imaging of fluorescently labelled budding yeast to measure times from division to budding (G1) and ...
Hagimori Keiichi - - 2007
A DNA-damaging agent, bleomycin, arrests the cell cycle at the G2 phase of Jurkat cells, which are defective in the G1 checkpoint, while microtubule-disrupting colchicine arrests it at M phase. Fungal cyclopeptides, malformin A1 and malformin C, were found to abrogate bleomycin-induced G2 arrest (IC(50); 0.48 microM and 0.9 nM, ...
Piperdi Bilal - - 2007
Both erlotinib (E) and bortezomib (B) have shown single-agent activity in patients with non-small cell lung cancer. We studied the combination of these two novel biologic agents in vitro using a panel of non-small cell lung cancer cell lines. The growth inhibitory effect of E and B were determined by ...
Serafim Teresa L - - 2008
PURPOSE: Natural products represent a rich reservoir of potential small molecule inhibitors exhibiting antiproliferative and tumoricidal properties. An example is the isoquinoline alkaloid berberine, which is found in plants such as goldenseal (Hydrastis canadensis). Studies have shown that berberine is able to trigger apoptosis in different malignant cell lines, and ...
Rybaczek Dorota - - 2007
Immunocytochemistry using alpha-phospho-H2AX antibodies shows that hydroxyurea (HU), an inhibitor of ribonucleotide reductase, and aphidicolin (APH), an inhibitor of DNA-polymerases alpha and delta, may promote formation of phospho-H2AX foci in late S/G2-phase cells in root meristems of Vicia faba. Although fluorescent foci spread throughout the whole area of nucleoplasm, large ...
Martín-López Alicia - - 2007
In previous experiments with the 55-6 hybridoma cell line, we showed that cell stimulation with anti-mouse surface immunoglobulin G antibody (anti-mIgG) increased both CD40 expression and specific monoclonal antibody (mAb) production rate. Cell preincubation with lipopolysaccharide (LPS) prior to anti-mIgG stimulation enhanced these results. Moreover, the expression of both CD40 ...
Tripodi Farida - - 2007
Protein kinase CK2 is a heterotetramer composed of two catalytic and two regulatory subunits. In Saccharomyces cerevisiae the catalytic subunits (alpha and alpha') are encoded by the CKA1, CKA2 genes. cka1Deltacka2(ts) mutants arrest cell cycle in both G1 and G2/M at 37 degrees C. Hence, it has been proposed that ...
Männistö Marjo - - 2007
BACKGROUND: Here we report on studies that probe whether the intracellular kinetics of plasmid DNA (pDNA) and cell surface glycosaminoglycans (GAGs) are modified during the cell cycle in a way that can be correlated with changes in gene transfer efficiency with poly(ethyleneimine) (PEI) and poly-L-lysine (PLL) polyplexes. METHODS: Synchronized D407 ...
Kondylis Vangelis - - 2007
During the cell cycle, the Golgi, like other organelles, has to be duplicated in mass and number to ensure its correct segregation between the two daughter cells. It remains unclear, however, when and how this occurs. Here we show that in Drosophila S2 cells, the Golgi likely duplicates in mass ...
Bjerregaard Henning - - 2007
Cadmium (Cd) is an important industrial and environmental pollutant, and the kidney is the primary organ to be affected. To elucidate the effects of Cd on cell proliferation, an epithelial cell line (A6) originally derived from the distal part of the Xenopus laevis kidney was cultured in media containing 10% ...
Zinzalla Vittoria - - 2007
The rapamycin-sensitive (TOR) signalling pathway in Saccharomyces cerevisiae controls growth and cell proliferation in response to nutrient availability. Rapamycin treatment causes cells to arrest growth in G1 phase. The mechanism by which the inhibition of the TOR pathway regulates cell cycle progression is not completely understood. Here we show that ...
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