329 research outputs found

    Controlling ultrafast laser writing in silica glass by pulse temporal contrast

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    Control of laser writing in transparent dielectrics using temporal contrast of light pulses is demonstrated. Anisotropic nanopores in silica glass are produced by high-contrast of 10^7 femtosecond Yb: KGW laser pulses rather than low-contrast of 10^3 Yb fiber laser pulses. Low-contrast pulses are useful for creating lamellar birefringent structures, possibly driven by quadrupole nonlinear current. The difference originates in the fiber laser storing third of its energy in a post-pulse of 200 ps duration. The absorption of this low-intensity fraction of the pulse by laser-induced transient defects with relatively long lifetime and low excitation energy, such as self-trapped holes, drastically changes the kinetics of energy deposition and type of material modification

    Organophosphate esters (OPEs)in Chinese foodstuffs: Dietary intake estimation via a market basket method, and suspect screening using high-resolution mass spectrometry

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    Despite of the ubiquity of organophosphate esters (OPEs)in various environmental matrices, information regarding the dietary intakes of OPEs is currently limited. To better understand dietary exposure and intake, the present study investigated 11 OPE flame retardants (FRs)in 105 co

    The Imperata grasslands of tropical Asia: area, distribution, and typology

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    The rehabilitation or intensified use of Imperata grasslands will require a much better understanding of their area, distribution, and characteristics. We generated estimates of the area of Imperata grasslands in tropical Asia, and suggested a typology of Imperata grasslands that may be useful to define the pathways toward appropriate land use intensification. We conclude that the area of Imperata grasslands in Asia is about 35 million ha. This about 4% of the total land area. The countries with the largest area of Imperata grasslands are Indonesia (8.5 million ha) and India (8.0 million ha). Those with the largest proportion of their surface area covered with Imperata are Sri Lanka (23%), the Philippines (17%), and Vietnam (9%). Laos, Thailand, Myanmar, and Bangladesh evidently all have similar proportions of their land area infested with Imperata (about 3 to 4%). Malaysia (< 1%), Cambodia (1%), and the southern part of China (2%) have but a minor proportion of their total land area in Imperata. The species was found widely distributed on the full range of soil orders. It occupied both fertile (e.g. some of the Inceptisols and Andisols) and infertile soils (Ultisols and Oxisols) across a wide range of climates and elevations. Imperata lands fall into four mapping scale-related categories: Mega-grasslands, itmacro-grasslands, meso-grasslands, and micro-grasslands. The mega-grasslands are often referred to as ‘sheet Imperata’. They are the large contiguous areas of Imperata that would appear on small-scale maps of say 1:1,000,000. We propose that this basic typology be supplemented with a number of additional components that have a key influence on intensification pathways: land quality, market access, and the source of power for tillage. The typology was applied in a case study of Indonesian villages in the vicinity of Imperata grasslands. We propose an international initiative to map and derive a more complete and uniform picture of the area of the Imperata grasslands. This should include selected studies to understand conditions at the local level. These are critical to build the appreciation of change agents for the indigenous systems of resource exploitation, and how they relate to local needs, values and constraints

    Glioblastoma cellular cross-talk converges on NF-κB to attenuate EGFR inhibitor sensitivity

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    Funding Information: We thank Dr. David James, Dr. Frederick Lang, Dr. Cameron Brennan, and Dr. Harley Kornblum for GBM-PDX neurospheres. We thank Dr. Karen Arden for continuous support and critical evaluation of the results. We thank Dr. Robert Davis, Dr. German Gomez, Dr. Tiffany Taylor, Dr. Rachel Reed, Dr. Melissa Mcalonis, and Dr. Sora Lee for technical support. In memory of Rosa Lupo. This work was supported by the Defeat GBM Research Collaborative, a subsidiary of the National Brain Tumor Society (F.B.F. and P.S.M.), R01-NS080939 (F.B.F.), the James S. McDonnell Foundation (F.B.F.), the National Cancer Institute (2T32CA009523-29A1) (A.H.T), and 1RO1NS097649-01 (C.C.C.). C.Z. was partially supported by an American-Italian Cancer Foundation post-doctoral research fellowship. F.L. received a Gao Feng Gao Yuan Scholarship Award. T.C.G., A.K.S., P.S.M., W.K.C., and F.B.F. receive salary and additional support from the Ludwig Institute for Cancer Research. Publisher Copyright: © 2017 Zanca et al.In glioblastoma (GBM), heterogeneous expression of amplified and mutated epidermal growth factor receptor (EGFR) presents a substantial challenge for the effective use of EGFR-directed therapeutics. Here we demonstrate that heterogeneous expression of the wild-type receptor and its constitutively active mutant form, EGFRvIII, limits sensitivity to these therapies through an interclonal communication mechanism mediated by interleukin-6 (IL-6) cytokine secreted from EGFRvIII-positive tumor cells. IL-6 activates a NF-κB signaling axis in a paracrine and autocrine manner, leading to bromodomain protein 4 (BRD4)-dependent expression of the prosurvival protein survivin (BIRC5) and attenuation of sensitivity to EGFR tyrosine kinase inhibitors (TKIs). NF-κB and survivin are coordinately up-regulated in GBM patient tumors, and functional inhibition of either protein or BRD4 in in vitro and in vivo models restores sensitivity to EGFR TKIs. These results provide a rationale for improving anti-EGFR therapeutic efficacy through pharmacological uncoupling of a convergence point of NF-κB-mediated survival that is leveraged by an interclonal circuitry mechanism established by intratumoral mutational heterogeneity.publishersversionPeer reviewe

    FoxQ1 Overexpression Influences Poor Prognosis in Non-Small Cell Lung Cancer, Associates with the Phenomenon of EMT

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    BACKGROUND: We determined the expression of forkhead box Q1 (FoxQ1), E-cadherin (E-cad), Mucin 1 (MUC1), vimentin (VIM) and S100 calcium binding protein A4 (S100A4), all epithelial-mesenchymal transition (EMT) indicator proteins in non-small cell lung cancer (NSCLC) tissue samples. We also investigated the relationship between these five proteins expression and other clinicopathologic factors in NSCLC. Finally, we assessed the potential value of these markers as prognostic indicators of survival in NSCLC's patients. METHODS: Quantitative real-time PCR and immunohistochemistry were used to characterize the expression of the FoxQ1 mRNA and protein in NSCLC. Expression of transcripts and translated products for the other four EMT indicator proteins was assessed by immunohistochemistry in the same clinical NSCLC samples. RESULTS: FoxQ1 mRNA and protein were up-regulated in NSCLC compared with normal tissues (P = 0.015 and P<0.001, respectively). Expression of FoxQ1 in adenocarcinoma was higher than in squamous cell carcinoma (P = 0.005), and high expression of FoxQ1 correlated with loss of E-cad expression (P = 0.012), and anomalous positivity of VIM (P = 0.024) and S100A4 (P = 0.004). Additional survival analysis showed that high expression of FoxQ1 (P = 0.047) and E-cad (P = 0.021) were independent prognostic factors. CONCLUSION: FoxQ1 maybe plays a specific role in the EMT of NSCLC, and could be used as a prognostic factor for NSCLC

    NF-κB Hyper-Activation by HTLV-1 Tax Induces Cellular Senescence, but Can Be Alleviated by the Viral Anti-Sense Protein HBZ

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    Activation of I-κB kinases (IKKs) and NF-κB by the human T lymphotropic virus type 1 (HTLV-1) trans-activator/oncoprotein, Tax, is thought to promote cell proliferation and transformation. Paradoxically, expression of Tax in most cells leads to drastic up-regulation of cyclin-dependent kinase inhibitors, p21CIP1/WAF1 and p27KIP1, which cause p53-/pRb-independent cellular senescence. Here we demonstrate that p21CIP1/WAF1-/p27KIP1-mediated senescence constitutes a checkpoint against IKK/NF-κB hyper-activation. Senescence induced by Tax in HeLa cells is attenuated by mutations in Tax that reduce IKK/NF-κB activation and prevented by blocking NF-κB using a degradation-resistant mutant of I-κBα despite constitutive IKK activation. Small hairpin RNA-mediated knockdown indicates that RelA induces this senescence program by acting upstream of the anaphase promoting complex and RelB to stabilize p27KIP1 protein and p21CIP1/WAF1 mRNA respectively. Finally, we show that down-regulation of NF-κB by the HTLV-1 anti-sense protein, HBZ, delay or prevent the onset of Tax-induced senescence. We propose that the balance between Tax and HBZ expression determines the outcome of HTLV-1 infection. Robust HTLV-1 replication and elevated Tax expression drive IKK/NF-κB hyper-activation and trigger senescence. HBZ, however, modulates Tax-mediated viral replication and NF-κB activation, thus allowing HTLV-1-infected cells to proliferate, persist, and evolve. Finally, inactivation of the senescence checkpoint can facilitate persistent NF-κB activation and leukemogenesis

    miRNA-135a promotes breast cancer cell migration and invasion by targeting HOXA10

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    <p>Abstract</p> <p>Background</p> <p>miRNAs are a group of small RNA molecules regulating target genes by inducing mRNA degradation or translational repression. Aberrant expression of miRNAs correlates with various cancers. Although miR-135a has been implicated in several other cancers, its role in breast cancer is unknown. <it>HOXA10 </it>however, is associated with multiple cancer types and was recently shown to induce p53 expression in breast cancer cells and reduce their invasive ability. Because <it>HOXA10 </it>is a confirmed miR-135a target in more than one tissue, we examined miR-135a levels in relation to breast cancer phenotypes to determine if miR-135a plays role in this cancer type.</p> <p>Methods</p> <p>Expression levels of miR-135a in tissues and cells were determined by poly (A)-RT PCR. The effect of miR-135a on proliferation was evaluated by CCK8 assay, cell migration and invasion were evaluated by transwell migration and invasion assays, and target protein expression was determined by western blotting. GFP and luciferase reporter plasmids were constructed to confirm the action of miR-135a on downstream target genes including <it>HOXA10</it>. Results are reported as means ± S.D. and differences were tested for significance using 2-sided Student"s t-test.</p> <p>Results</p> <p>Here we report that miR-135a was highly expressed in metastatic breast tumors. We found that the expression of miR-135a was required for the migration and invasion of breast cancer cells, but not their proliferation. <it>HOXA10</it>, which encodes a transcription factor required for embryonic development and is a metastasis suppressor in breast cancer, was shown to be a direct target of miR-135a in breast cancer cells. Our analysis showed that miR-135a suppressed the expression of <it>HOXA10 </it>both at the mRNA and protein level, and its ability to promote cellular migration and invasion was partially reversed by overexpression of <it>HOXA10</it>.</p> <p>Conclusions</p> <p>In summary, our results indicate that miR-135a is an onco-miRNA that can promote breast cancer cell migration and invasion. <it>HOXA10 </it>is a target gene for miR-135a in breast cancer cells and overexpression of <it>HOXA10 </it>can partially reverse the miR-135a invasive phenotype.</p

    Catecholamine up-regulates MMP-7 expression by activating AP-1 and STAT3 in gastric cancer

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    <p>Abstract</p> <p>Background</p> <p>Stress, anxiety and depression can cause complex physiological and neuroendocrine changes, resulting in increased level of stress related hormone catecholamine, which may constitute a primary mechanism by which physiological factors impact gene expression in tumors. In the present study, we investigated the effects of catecholamine stimulation on MMP-7 expression in gastric cancer cells and elucidated the molecular mechanisms of the up-regulation of MMP-7 level by catecholamine through an adrenergic signaling pathway.</p> <p>Results</p> <p>Increased MMP-7 expression was identified at both mRNA and protein levels in the gastric cancer cells in response to isoproterenol stimulation. β2-AR antigonist effectively abrogated isoproterenol-induced MMP-7 expression. The activation of STAT3 and AP-1 was prominently induced by isoproterenol stimulation and AP-1 displayed a greater efficacy than STAT3 in isoproterenol-induced MMP-7 expression. Mutagenesis of three STAT3 binding sites in MMP-7 promoter failed to repress the transactivation of MMP-7 promoter and silencing STAT3 expression was not effective in preventing isoproterenol-induced MMP-7 expression. However, isoproterenol-induced MMP-7 promoter activities were completely disappeared when the AP-1 site was mutated. STAT3 and c-Jun could physically interact and bind to the AP-1 site, implicating that the interplay of both transcriptional factors on the AP-1 site is responsible for isoproterenol-stimulated MMP-7 expression in gastric cancer cells. The expression of MMP-7 in gastric cancer tissues was found to be at the site where β2-AR was overexpressed and the levels of MMP-7 and β2-AR were the highest in the metastatic locus of gastric cancer.</p> <p>Conclusions</p> <p>Up-regulation of MMP-7 expression through β2-AR-mediated signaling pathway is involved in invasion and metastasis of gastric cancer.</p
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