Survivin silencing and TRAIL expression using oncolytic adenovirus increase anti-tumorigenic activity in gemcitabine-resistant pancreatic cancer cells

In this study, we demonstrated that survivin downregulation with TRAIL expression greatly enhanced the cytotoxic death of pancreatic cancer cells after gemcitabine treatment. Using real-time RT-PCR, we analyzed five survivin shRNAs to identify the best target sequence for suppression of human survivin, with the goal of treating gemcitabine-resistant pancreatic cancer cells. Survivin shRNA 5, corresponding to target 5, showed the greatest reduction in survivin mRNA levels. Furthermore, combined treatment with survivin shRNA-expressing adenovirus with gemcitabine plus TRAIL decreased uncleaved PARP and increased consequent PARP cleavage, which was correlated with the greatest levels of survivin downregulation and cell death. These results indicate that survivin functions as a common mediator of gemcitabine- and TRAIL-induced cell death. Using a nude mouse model implanted with MiaPaCa-2 pancreatic cancer cells, we observed tumor regression induced by an oncolytic adenovirus expressing survivin shRNA and TRAIL plus gemcitabine. Together, our findings provide a strong rationale for treating pancreatic cancer patients with both gemcitabine and oncolytic adenovirus armed with survivin shRNA and TRAIL.     

Discovery and characterization of a novel 7-aminopyrazolo[1,5-a]pyrimidine analog as a potent hepatitis C virus inhibitor

We describe a novel 7-aminopyrazolo[1,5-a]pyrimidine (7-APP) derivative as a potent hepatitis C virus (HCV) inhibitor. A series of 7-APPs was synthesized and evaluated for inhibitory activity against HCV in different cell culture systems. The synthesis and preliminary structure-activity relationship study of 7-APP are reported.     

<Emphasis Type="Italic">Arabidopsis</Emphasis> <Emphasis Type="Italic">thaliana</Emphasis> Rubisco small subunit transit peptide increases the accumulation of <Emphasis Type="Italic">Thermotoga maritima</Emphasis> endoglucanase Cel5A in chloroplasts of transgenic tobacco plants

Over the past decade various approaches have been used to increase the expression level of recombinant proteins in plants. One successful approach has been to target proteins to specific subcellular sites/compartments of plant cells, such as the chloroplast. In the study reported here, hyperthermostable endoglucanase Cel5A was targeted into the chloroplasts of tobacco plants via the N-terminal transit peptide of nuclear-encoded plastid proteins. The expression levels of Cel5A transgenic lines were then determined using three distinct transit peptides, namely, the light-harvesting chlorophyll a/b-binding protein (CAB), Rubisco small subunit (RS), and Rubisco activase (RA). RS:Cel5A transgenic lines produced highly stable active enzymes, and the protein accumulation of these transgenic lines was up to 5.2% of the total soluble protein in the crude leaf extract, remaining stable throughout the life cycle of the tobacco plant. Transmission election microscopy analysis showed that efficient targeting of Cel5A protein was under the control of the transit peptide.     

In situ laccase-assisted overdyeing of denim using flavonoids

A laccase-mediated system for denim overdyeing using phenolic compounds was developed. Laccase from ascomycete Myceliophthora thermophila was able to oxidize phenolic compounds such as catechol and catechin and mediate their attachment to denim surfaces. Laccase-generated polymers gave rise to new coloration states from dark brown to green-yellow and replaced dyes in the overdyeing process. Process parameters, such as enzyme dosage, incubation time and presence of mediator, were studied by considering a compromise between the highest overdyeing level and lower energy/products consumption (2 U/mL laccase; 4 h incubation in the absence of mediator). Enzyme-generated polymers were followed by UV/Vis spectrophotometry and their level of attachment to denim surfaces was evaluated by means of spectral values quantification [k/s, Kubelka-Munk relationship (k=absorption coefficient, s=scattering coefficient)]. Overdyeing of denim with phenolics, such as catechol or catechin, was successfully achieved with acceptable levels in terms of durability.     

Laccases for enzymatic colouration of unbleached cotton

The concept presented in this paper is the utilisation of the natural flavonoids present in cotton as anchors to attach other phenolic compounds to the fiber surface. Laccase can catalyze the oxidation of flavonoids in solution producing quinones that can be further polymerised and grafted onto surface of the cotton providing yellow to brown colouration, depending on the external flavonoids used and on the reaction conditions. Factors such as temperature, time of reaction, pretreatment of cotton, mechanical agitation and the role of an organic solvent were studied in order to improve this laccase colouration reaction. After dyeing, colour measurements and fastness tests (washing, friction and weathering fastness) were performed. A strong mechanical agitation, an increased reaction temperature (from 30 to 50 °C), and the addition of an organic solvent improved dyeing.

The natural flavonoids present on cotton were found to play an important role on the grafting reaction, improving dyeing and colour fastness. Since the traditional bleaching pretreatment of cotton removes these natural flavonoids from cotton, the proposed laccase colouration reaction could be carried out without a previous bleaching treatment resulting in a more environmentally friendly process.     

Increased nicotianamine biosynthesis confers enhanced tolerance of high levels of metals, in particular nickel, to plants

Nicotianamine, a plant-derived chelator of metals, is produced by the trimerization of S-adenosylmethionine catalyzed by nicotianamine synthase. We established transgenic Arabidopsis and tobacco plants that constitutively overexpress the barley nicotianamine synthase gene. Nicotianamine synthase overexpression resulted in increased biosynthesis of nicotianamine in transgenic plants, which conferred enhanced tolerance of high levels of metals, particularly nickel, to plants. Promoter activities of four nicotianamine synthase genes in Arabidopsis were all increased in response to excess nickel, suggesting that nicotianamine plays an important role in the detoxification of nickel in plants. Furthermore, transgenic tobacco plants with a high level of nicotianamine grew well in a nickel-enriched serpentine soil without developing any symptoms of nickel toxicity. Our results indicate that nicotianamine plays a critical role in metal detoxification, and this can be a powerful tool for use in phytoremediation.     

Hoeflea halophila sp. nov., a novel bacterium isolated from marine sediment of the East Sea, Korea

A Gram-negative, aerobic, motile, straight or curved rod-shaped marine bacterium was isolated from marine sediment of the East Sea, Korea. The isolated strain, JG120-1^T, grows with 0–5 % (w/v) NaCl and at 15–30 °C and pH 6–9. α-galactosidase activity test was positive. Comparative 16S rRNA gene sequence studies showed that this strain belonged to the Alphaproteobacteria and was the most closely related to Hoeflea alexandrii AM1 V30^T, Hoeflea phototrophica DFL-43^T and Hoeflea marina LMG 128^T (98.9, 97.9 and 97.0 % 16S rRNA gene sequence similarities, respectively). Strain JG120-1^T was found to possess summed feature 8 (C18:1ω7c/C18:1ω6c, 71.11 %) as the major cellular fatty acid. The major ubiquinone was determined to be Q-10. Polar lipids include phosphatidylglycerol, phosphatidylethanolamine, sulfoquinovosyl diacylglycerol, phosphatidylcholine and phosphatidylmonomethylethanolamine. The G+C content of the genomic DNA of strain JG120-1^T was determined to be 57.8 mol %. DNA–DNA relatedness data indicated that strain JG120-1^T represents a distinct species that is separate from H. phototrophica DFL-43^T, H. marina LMG128^T and H. alexandrii AM1 V30^T. On the basis of polyphasic evidences, it is proposed that strain JG120-1^T (= KCTC 23107^T = JCM 16715^T) represents the type strain of a novel species, Hoeflea halophila sp. nov.