Epstein-Barr virus upregulates phosphorylated heat shock protein 27 kDa in carcinoma cells using the phosphoinositide 3-kinase/Akt pathway

Gastric cancer is the most common cancer in Japan and infection with Epstein-Barr virus (EBV) is responsible for about 10% of gastric cancers worldwide. Although EBV infection may be involved at an early stage of gastric carcinogenesis, the mechanisms underlying its involvement remain unknown. To investigate the role of EBV in gastric carcinogenesis, we performed proteomic analyses of an EBV-infected gastric carcinoma cell line NU-GC-3 (EBV(+)) and its uninfected control (EBV(-)). 2-DE was combined with MS to identify differentially expressed proteins. We found that EBV infection upregulated one of the phosphorylated heat shock protein 27 kDa (HSP27). The phosphorylated HSP27 isoform which increased in EBV(+) cells can be induced by both heat shock and arsenite. The increase of phosphorylated HSP27 in EBV(+) cells was reduced by treatment with the phosphoinositide 3-kinase (PI3K) inhibitors (LY294002 and wortmannin). In addition, we found increased levels of phosphorylated Akt in EBV(+) cells. These findings suggest that EBV infection upregulates the phosphorylation of HSP27 via the PI3K/Akt pathway. Thus, activation of the PI3K/Akt pathway may contribute to the establishment of a malignant phenotype in EBV-infected gastric carcinomas.     

Hydrothermal Synthesis of Metal Oxide Nanoparticles at Supercritical Conditions

Hydrothermal synthesis of CeO₂ and AlO(OH) were conducted using a flow type apparatus over the range of temperature from 523 to 673 K at 30 MPa. Nanosize crystals were formed at supercritical conditions. The mechanism of nanoparticle formation at supercritical conditions was discussed based on the metal oxide solubility and kinetics of the hydrothermal synthesis reaction. The reaction rate of Ce(NO₃)₃ and Al(NO₃)₃ was evaluated using a flow type reactor. The Arrhenius plot of the first order rate constant fell on a straight line in the subcritical region, while it deviated from the straight line to the higher values above the critical point. The solubility of Ce(OH)₃ and AlO(OH) was estimated by using a modified HKF model in a wide range of pH and temperature. In acidic conditions, where hydrothermal synthesis reaction is concerned, solubility gradually decreased with increasing temperature and then drastically dropped above the critical point. The trend of the solubility and the kinetics around the critical point could be explained by taking account of the dielectric constant effect on the reactions. There are two reasons why nanoparticle are formed at supercritical conditions. Larger particles are produced at subcritical conditions due to Ostwald ripening; that could not be observed in supercritical water because of the extremely low solubility. Second reason is the faster nucleation rate in supercritical water because of the lower solubility and the extremely fast reaction rate.     

Total synthesis of a natural antioxidant and structure-activity relationships of related compounds.

A total synthesis of benzodioxole derivative 1 was achieved via a palladium(0)-catalyzed cross-coupling reaction in a 68% overall yield (4 steps). A novel series of benzodioxoles bearing a variety of aromatic and heterocyclic rings was also prepared and the antioxidative activity evaluated using in vitro model systems. Structure-activity studies revealed that i) intramolecular hydrogen-bonding in the phenol moiety reduced activity, ii) introduction of disubstituents at the ortho location relative to the phenol increased activity, and iii) the methylenedioxy function contributed to stabilization of the phenoxy radical. Among of these compounds, 5,7-di-(4-methoxyphenyl)-4-methoxy-6-hydroxy-1,3-benzodioxole (7p) was the most favorable agent and more potent than n-propyl gallate.     

Utilizing nonlinear phenomena to locate grazing in the constrained motion of a cantilever beam

Grazing behavior in soft impact dynamics of a harmonically based excited flexible cantilever beam is investigated. Numerical and experimental methods are employed to study the dynamic behavior of macro- and micro-scale cantilever beam–impactor systems. For off-resonance excitation at two and a half times the fundamental frequency, the response of the oscillating cantilever experiences period doubling as the separation distance or clearance between the beam axis and the contact surface is decreased. The nonlinear phenomenon is studied by using phase portraits, Poincaré sections, and spectral analysis. Motivated by atomic force microscopy, this general dynamic behavior is studied as a means to locating the separation distance corresponding to grazing where the contact force is minimized.     

Optical manipulation of molecular function by chromophore-assisted light inactivation

In addition to simple on/off switches for molecular activity, spatiotemporal dynamics are also thought to be important for the regulation of cellular function. However, their physiological significance and in vivo importance remain largely unknown. Fluorescence imaging technology is a powerful technique that can reveal the spatiotemporal dynamics of molecular activity. In addition, because imaging detects the correlations between molecular activity and biological phenomena, the technique of molecular manipulation is also important to analyze causal relationships. Recent advances in optical manipulation techniques that artificially perturb molecules and cells via light can address this issue to elucidate the causality between manipulated target and its physiological function. The use of light enables the manipulation of molecular activity in microspaces, such as organelles and nerve spines. In this review, we describe the chromophore-assisted light inactivation method, which is an optical manipulation technique that has been attracting attention in recent years.     

Suprapolymer Structures from Nanostructured Polymer Particles

Divide and conquer : Polymer nanoparticles with phase‐separation structures prepared with block copolymers and homopolymer blends were used to fabricate unique suprapolymer structures by cross‐linking one polymer moiety and dissolving the other (see scheme; PI=polyisoprene, PSt=polystyrene).

     

Antitumor effect of liposomal histone deacetylase inhibitor-lipid conjugates in vitro

Histone deacetylase inhibitor (HDACI), suberoylanilide hydroxamic acid (SAHA), approved by the Food and Drug Administration (FDA) for the treatment of cutaneous T cell lymphoma, is a promising new treatment strategy for various cancers. In this study, we hypothesized that a liposomal formulation of HDACI might efficiently deliver HDACI into tumors. To incorporate HDACI efficiently into the liposomal membrane, we synthesized six HDACI-lipid conjugates, in which polyethylene glycol(2000) (PEG(2000))-lipid or cholesterol (Chol) was linked with a potent hydroxamic acid, HDACI, SAHA or K-182, by cleavable linkers, such as ester, carbamide and disulfide bonds. Liposomal HDACI-lipid conjugates were prepared with distearoylphosphatidylcholine (DSPC) and HDACI-Chol conjugate or with DSPC, Chol and HDACI-PEG-lipid conjugates, and their cytotoxicities were evaluated for human cervix tumor HeLa and mouse colon tumor Colon 26 cells. Among the liposomes, liposomal oleyl-PEG(2000)-SAHA conjugated with SAHA and oleyl-PEG(2000) via a carbamate linker showed higher cytotoxicity via hyperacetylation of histone H3 and induction of caspase 3/7 activity. These results suggested that liposomal HDACI-lipid conjugates may be a potential tool for cancer therapy.     

Separation and quantitative determination of 6α-hydroxycortisol and 6β-hydroxycortisol in human urine by high-performance liquid chromatography with ultraviolet absorption detection

The present study developed an high-performance liquid chromatography (HPLC) method for the simultaneous determination of urinary metabolites of endogenous cortisol, 6α-hydroxycortisol (6α-OHF) and 6β-hydroxycortisol (6β-OHF), in human urine, using 6α-hydroxycorticosterone as internal standard. 6α-OHF and 6β-OHF were extracted from urine with ethyl acetate by using a Sep-Pak C₁₈ plus cartridge. Separation of the stereoisomers was achieved on a reversed-phase hybrid column by a gradient elution of (A) 0.05 M KH₂PO₄–0.01 M CH₃COOH (pH 3.77) and (B) 0.05 M KH₂PO₄–0.01 M CH₃COOH/acetonitrile (2:3, v/v). 6α-OHF and 6β-OHF were well separated on an XTerra MS C₁₈ 5 μm column using two types of stepwise gradient elution program (programs 2 and 3). Resolutions of 6α-OHF and 6β-OHF were Rs = 4.41 for program 2 and Rs = 4.60 for program 3. The analysis was performed within 23~26 min, monitored by UV absorbance at 239 nm. The lower limits of detection of 6α-OHF and 6β-OHF were 0.80 ng per injection (s/n = ca. 8), and the lower limits of quantification were 5.02 ng/ml for 6α-OHF and 41.08 ng/ml for 6β-OHF, respectively. The within-day reproducibilities in the amounts of 6α-OHF and 6β-OHF determined were in good agreement with the actual amounts added, the relative errors being −5.37% and −3.73% (gradient 2) and −5.69% and −3.96% (gradient 3) for both 6α-OHF and 6β-OHF, respectively. The inter-assay precisions (RSDs) for 6α-OHF and 6β-OHF were less than 1.99% (gradient 2) and 2.61% (gradient 3), respectively. The present HPLC method was applied to the measurement of 6α-OHF and 6β-OHF in urine to evaluate the time courses of 6α-hydroxylation and 6β-hydroxylation clearances of cortisol during 40 days for phenotyping CYP3A in a healthy subject.     

Two-directional synthesis and stereochemical assignment toward a C2 symmetric oxasqualenoid (+)-intricatetraol

The asymmetric synthesis of tetraol (+)-3, a degradation product derived from a C2 symmetric oxasqualenoid intricatetraol 1, has been achieved through the two-directional synthesis starting from diol 7, realizing the further additional assignment of the incomplete stereostructure of 1, the stereochemistry of which is difficult to determine otherwise.