Enhancer of zeste homolog 2 (EZH2) is a critical component of the polycomb-repressive complex 2 (PRC2), which is involved in gene silencing and histone H3 lysine 27 methylation. EZH2 has a master ...regulatory function in controlling such processes as stem cell differentiation, cell proliferation, early embryogenesis and X chromosome inactivation. Although benign epithelial cells express very low levels of EZH2, increased levels of EZH2 have been observed in aggressive solid tumors such as those of the prostate, breast and bladder. The mechanism by which EZH2 mediates tumor aggressiveness is unclear. Here, we demonstrate that EZH2 mediates transcriptional silencing of the tumor suppressor gene E-cadherin by trimethylation of H3 lysine 27. Histone deacetylase inhibitors can prevent EZH2-mediated repression of E-cadherin and attenuate cell invasion, suggesting a possible mechanism that may be useful for the development of therapeutic treatments. Taken together, these observations provide a novel mechanism of E-cadherin regulation and establish a functional link between dysregulation of EZH2 and repression of E-cadherin during cancer progression.
Tumor angiogenesis is of paramount importance in solid tumor development. Elevated serum levels of YKL-40, which is a secreted heparin-binding glycoprotein, have been associated with a worse ...prognosis from various advanced human cancers. Yet the role of YKL-40 activity in these cancers is still missing. In this study, we showed that ectopic expression of YKL-40 in MDA-MB-231 breast cancer cells and in HCT-116 colon cancer cells led to larger tumor formation with an extensive angiogenic phenotype than did control cancer cells in mice. Affinity-purified recombinant YKL-40 protein promoted vascular endothelial cell angiogenesis in vitro, the effects of which are similar to the activities observed using MDA-MB-231 and HCT-116 cell-conditioned medium after transfection with YKL-40. Furthermore, YKL-40 was found to induce coordination of membrane-bound receptor syndecan-1 and integrin alpha(v)beta(3) and to activate an intracellular signaling cascade, including focal adhesion kinase and mitogen-activated protein kinase extracellular signal-related kinase1/2 in endothelial cells. Moreover, blockade of YKL-40 using small-interfering RNA gene knockdown suppressed tumor angiogenesis in vitro and in vivo. Immunohistochemical analysis of human breast cancer showed a correlation between YKL-40 expression and blood vessel density. These findings provide novel insights into angiogenic activities and molecular mechanisms of YKL-40 in cancer development.
Ceramic materials for thermal barrier coatings Cao, X.Q.; Vassen, R.; Stoever, D.
Journal of the European Ceramic Society,
2004, 2004-1-00, 20040101, Letnik:
24, Številka:
1
Journal Article
Recenzirano
This paper summarizes the basic properties of ceramic materials for thermal barrier coatings. Ceramics, in contrast to metals, are often more resistant to oxidation, corrosion and wear, as well as ...being better thermal insulators. Except yttria stabilized zirconia, other materials such as lanthanum zirconate and rare earth oxides are also promising materials for thermal barrier coatings.
► Medium manganese steel. ► Intercritical annealing treatment. ► Large fractioned austenite. ► Excellent mechanical properties. ► Enhanced TRIP effects.
Microstructure and mechanical properties of ...medium manganese steel (Fe–0.2C–5Mn) processed by annealing at 650
°C with annealing time up to 12
h after accelerated cooling were studied. It was found that the martensite structure was gradually transformed into a superfine ferrite and austenite duplex structure by austenite reverted transformation during annealing process. The annealing heat treatment results in a large volume fraction of austenite (34%) and an excellent combination of ultimate tensile strength (∼1000
MPa) and total elongation (>40%) at room temperature. The ultrahigh tensile strength and improved ductility of present steel were mainly attributed to the enhanced phase transformation induced plasticity due to the large fractioned austenite.
► Hierarchically porous Co3O4 film is prepared via a colloidal crystal template. ► Co3O4 film with high capacitance as cathode material for supercapacitors. ► Hierarchically porous structure helps to ...relax the volume change.
Hierarchically porous Co3O4 film is prepared via a hydrothermal synthesis method based on a self-assembled monolayer polystyrene (PS) spheres template. The as-prepared Co3O4 film shows a two-layer structure: substructure is composed of Co3O4 monolayer hollow-sphere array and the superstructure consists of porous net-like Co3O4 nanoflakes possessing continuous mesopores ranging from 2 to 5nm. The pseudocapacitive behavior of the hierarchically porous Co3O4 film is investigated by cyclic voltammograms (CV) and galvanostatic charge–discharge tests in 2M KOH. As cathode material for supercapacitors, the hierarchically porous Co3O4 film exhibits noticeable pseudocapacitive properties with a capacitance of 454Fg−1 at 2Ag−1 as well as quite good cycling stability and high capacitance retention. Compared to the film prepared without template, the hierarchically porous film exhibits weaker polarization, higher capacitances and better cycling performance. The enhancement of pseudocapacitive properties are due to the hierarchically porous architecture, which provides fast ion/electron transfer and alleviates the structure degradation caused by volume expansion during the cycling process.
In this study, a novel method was proposed to obtain single cell protein (SCP) in yeast by using biogas slurry as culture medium. The results show that Nectaromyces rattus was the most efficient at ...producing SCP among the 7 different yeasts studied. Acetic acid was a better pH regulator than hydrochloric acid. After culture with the initial NH4+-N concentration 2,000 mg/L, C/N ratio 6:1, the initial pH 5.50 and rotation speed of 200 rpm, a total cell dry weight of 12.58 g/L with 35.96% protein content was obtained. Nineteen amino acids accounted for 46.85% of cell dry weight, and proline content was as high as 12.0% of the cell dry weight. However, sulfur-containing amino acids, including methionine and cystine, were deficient. Further research should focus on the high cell density culture to increase SCP production.
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