411 research outputs found
C5 Extract Induces Apoptosis in B16F10 Murine Melanoma Cells through Extrinsic and Intrinsic Apoptotic Pathways and Sub-G1 Phase Arrest
Purpose: To investigate the anti-cancer activities of C5 extract (C5E), a new herbal preparation from Korea, on B16F10 cells.Methods: The anti-proliferative effects of C5E were assessed by culturing B16F10 cells in the presence or absence of C5E. Cell cycle progression was analyzed by PI staining using flow cytometry. The quantities of apoptosis-inducing proteins were measured by Western blot.Results: C5E inhibited the proliferation of B16F10 cells but not human keratinocytes. C5E induced S phase arrest by interfering with cell regulatory factors such as cyclins B1, D1, D3, and E, and cyclindependent kinase 2, in B16F10 cells. Furthermore, immunoblot analysis confirmed that treatment with C5E induced apoptosis and cleaved caspase-3, poly (ADP-ribose) polymerase, via extrinsic pathway, whereas Bcl-2 expression was down-regulated. In addition, the suppression of cell proliferation by C5E is through down-regulation of p-Akt, up-regulation of phosphatase and tensin homolog protein expression via phosphoinositol 3 kinase survival signaling pathways in B16F10 cells. The combined cytotoxic effects of C5E and vinblastine generated 10 % increase in activity in contrast to the sum of the inhibitory effects of the individual agents.Conclusion: C5E shows promising anti-cancer activity and can be a useful adjuvant with vinblastine in combination therapeutic treatment of skin cancer.Keywords: Melanoma, Apoptosis, Anti-cancer, p53, Vinblastine, Cell cycle arrest, Caspas
Enhanced anti-tumor effects of combined MDR1 RNA interference and human sodium/iodide symporter (NIS) radioiodine gene therapy using an adenoviral system in a colon cancer model
Using an adenoviral system as a delivery mediator of therapeutic gene, we investigated the therapeutic effects of the use of combined MDR1 shRNA and human NIS (hNIS) radioiodine gene therapy in a mouse colon xenograft model. In vitro uptake of Tc-99m sestamibi was increased approximately two-fold in cells infected with an adenovirus vector that expressed MDR1 shRNA (Ad-shMDR1) and I-125 uptake was 25-fold higher in cells infected with an adenovirus vector that expressed human NIS (Ad-hNIS) as compared with control cells. As compared with doxorubicin or I-131 treatment alone, the combination of doxorubicin and I-131 resulted in enhanced cytotoxicity for both Ad-shMDR1- and Ad-hNIS-infected cells, but not for control cells. In vivo uptake of Tc-99m sestamibi and Tc-99m pertechnetate was twofold and 10-fold higher for Ad-shMDR1 and Ad-hNIS-infected tumors as compared with tumors infected with a control adenovirus construct that expressed β-galactrosidase (Ad-LacZ), respectively. In mice treated with either doxorubicin or I-131 alone, there was a slight delay in tumor growth as compared to mice treated with Ad-LacZ. However, combination therapy with doxorubicin and I-131 induced further significant inhibition of tumor growth as compared with mice treated with Ad-LacZ. We have shown successful therapeutic efficacy of combined MDR shRNA and hNIS radioiodine gene therapy using an adenoviral vector system in a mouse colon cancer model. Adenovirus-mediated cancer gene therapy using MDR1 shRNA and hNIS would be a useful tool for the treatment of cancer cells expressing multi-drug resistant genes
Thermally nucleated magnetic reversal in CoFeB/MgO nanodots
Power consumption is the main limitation in the development of new high performance random access memory for portable electronic devices. Magnetic RAM (MRAM) with CoFeB/MgO based magnetic tunnel junctions (MTJs) is a promising candidate for reducing the power consumption given its non-volatile nature while achieving high performance. The dynamic properties and switching mechanisms of MTJs are critical to understanding device operation and to enable scaling of devices below 30 nm in diameter. Here we show that the magnetic reversal mechanism is incoherent and that the switching is thermally nucleated at device operating temperatures. Moreover, we find an intrinsic thermal switching field distribution arising on the sub-nanosecond time-scale even in the absence of size and anisotropy distributions or material defects. These features represent the characteristic signature of the dynamic properties in MTJs and give an intrinsic limit to reversal reliability in small magnetic nanodevices
Potential conservation of circadian clock proteins in the phylum Nematoda as revealed by bioinformatic searches
Although several circadian rhythms have been described in C. elegans, its molecular clock remains elusive. In this work we employed a novel bioinformatic approach, applying probabilistic methodologies, to search for circadian clock proteins of several of the best studied circadian model organisms of different taxa (Mus musculus, Drosophila melanogaster, Neurospora crassa, Arabidopsis thaliana and Synechoccocus elongatus) in the proteomes of C. elegans and other members of the phylum Nematoda. With this approach we found that the Nematoda contain proteins most related to the core and accessory proteins of the insect and mammalian clocks, which provide new insights into the nematode clock and the evolution of the circadian system.Fil: Romanowski, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; ArgentinaFil: Garavaglia, Matías Javier. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ing.genética y Biolog.molecular y Celular. Area Virus de Insectos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Goya, María Eugenia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ghiringhelli, Pablo Daniel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ing.genética y Biolog.molecular y Celular. Area Virus de Insectos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andres. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Spatio-temporal Models of Lymphangiogenesis in Wound Healing
Several studies suggest that one possible cause of impaired wound healing is
failed or insufficient lymphangiogenesis, that is the formation of new
lymphatic capillaries. Although many mathematical models have been developed to
describe the formation of blood capillaries (angiogenesis), very few have been
proposed for the regeneration of the lymphatic network. Lymphangiogenesis is a
markedly different process from angiogenesis, occurring at different times and
in response to different chemical stimuli. Two main hypotheses have been
proposed: 1) lymphatic capillaries sprout from existing interrupted ones at the
edge of the wound in analogy to the blood angiogenesis case; 2) lymphatic
endothelial cells first pool in the wound region following the lymph flow and
then, once sufficiently populated, start to form a network. Here we present two
PDE models describing lymphangiogenesis according to these two different
hypotheses. Further, we include the effect of advection due to interstitial
flow and lymph flow coming from open capillaries. The variables represent
different cell densities and growth factor concentrations, and where possible
the parameters are estimated from biological data. The models are then solved
numerically and the results are compared with the available biological
literature.Comment: 29 pages, 9 Figures, 6 Tables (39 figure files in total
Correction: MiR-34a/c-Dependent PDGFR-α/β Downregulation Inhibits Tumorigenesis and Enhances TRAIL-Induced Apoptosis in Lung Cancer.
[This corrects the article DOI: 10.1371/journal.pone.0067581.]
Localisation of Human Papillomavirus 16 E7 Oncoprotein Changes with Cell Confluence
E7 is one of the best studied proteins of human papillomavirus type 16, largely because of its oncogenic potential linked to cervical cancer. Yet the sub-cellular location of E7 remains confounding, even though it has been shown to be able to shuttle between the nucleus and the cytoplasm. Here we show with immunocytochemistry that E7 proteins are located in the nucleus and cytoplasm in sub-confluent cells, but becomes cytoplasmic in confluent cells. The change in E7's location is independent of time in culture, cell division, cell cycle phase or cellular differentiation. Levels of E7 are also increased in confluent cells as determined by Western blotting. Our investigations have also uncovered how different analytical techniques influence the observation of where E7 is localised, highlighting the importance of technical choice in such analysis. Understanding the localisation of E7 will help us to better comprehend the function of E7 on its target proteins
Prolonged Depression-Like Behavior Caused by Immune Challenge: Influence of Mouse Strain and Social Environment
Immune challenge by bacterial lipopolysaccharide (LPS) causes short-term
behavioral changes indicative of depression. The present study sought to explore
whether LPS is able to induce long-term changes in depression-related behavior
and whether such an effect depends on mouse strain and social context. LPS (0.83
mg/kg) or vehicle was administered intraperitoneally to female CD1 and C57BL/6
mice that were housed singly or in groups of 4. Depression-like behavior was
assessed with the forced swim test (FST) 1 and 28 days post-treatment.
Group-housed CD1 mice exhibited depression-like behavior 1 day post-LPS, an
effect that leveled off during the subsequent 28 days, while the behavior of
singly housed CD1 mice was little affected. In contrast, singly housed C57BL/6
mice responded to LPS with an increase in depression-like behavior that was
maintained for 4 weeks post-treatment and confirmed by the sucrose preference
test. Group-housed C57BL/6 mice likewise displayed an increased depression-like
behavior 4 weeks post-treatment. The behavioral changes induced by LPS in
C57BL/6 mice were associated with a particularly pronounced rise of
interleukin-6 in blood plasma within 1 day post-treatment and with changes in
the dynamics of the corticosterone response to the FST. The current data
demonstrate that immune challenge with LPS is able to induce prolonged
depression-like behavior, an effect that depends on genetic background (strain).
The discovery of an experimental model of long-term depression-like behavior
after acute immune challenge is of relevance to the analysis of the epigenetic
and pathophysiologic mechanisms of immune system-related affective
disorders
Measurement of B(t->Wb)/B(t->Wq) at the Collider Detector at Fermilab
We present a measurement of the ratio of top-quark branching fractions R= B(t
-> Wb)/B(t -> Wq), where q can be a b, s or a d quark, using lepton-plus-jets
and dilepton data sets with integrated luminosity of ~162 pb^{-1} collected
with the Collider Detector at Fermilab during Run II of the Tevatron. The
measurement is derived from the relative numbers of t-tbar events with
different multiplicity of identified secondary vertices. We set a lower limit
of R > 0.61 at 95% confidence level.Comment: 7 pages, 2 figures, published in Physical Review Letters; changes
made to be consistent with published versio
Search for ZZ and ZW Production in ppbar Collisions at sqrt(s) = 1.96 TeV
We present a search for ZZ and ZW vector boson pair production in ppbar
collisions at sqrt(s) = 1.96 TeV using the leptonic decay channels ZZ --> ll nu
nu, ZZ --> l l l' l' and ZW --> l l l' nu. In a data sample corresponding to an
integrated luminosity of 194 pb-1 collected with the Collider Detector at
Fermilab, 3 candidate events are found with an expected background of 1.0 +/-
0.2 events. We set a 95% confidence level upper limit of 15.2 pb on the cross
section for ZZ plus ZW production, compared to the standard model prediction of
5.0 +/- 0.4 pb.Comment: 7 pages, 2 figures. This version is accepted for publication by Phys.
Rev. D Rapid Communication
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