Quinolinone inhibits proliferation of gastric cancer cells and induces their apoptosis via down-regulation of the expression of pro-oncogene c-Myc

Purpose: To determine the anti-proliferative potential of quinolinone against gastric cancer cells, and the underlying mechanism of action.Methods: Quinolinone-mediated proliferative changes were measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, while its effect on apoptosis was determined by flow cytometry. Transwell and wound healing assays were used for the determination of the effect of quinolinone on cell invasion and migration. The effect of quinolinone on protein expression levels were assayed with western blotting.Results: Quinolinone caused reduction in gastric cancer cell viability, but it had no effect on normal (GES-1) cells. Treatment with 8 μM quinolinone reduced the viability of SNU-5 and SGC-7901 cells to 32 and 27 %, respectively. Moreover, 8 μM quinolinone induced 67.90 and 71.54 % apoptosis in SNU-5 and SGC-7901 cells, respectively. Quinolinone significantly increased the population of cells in G1 phase, and suppressed migration potential (p < 0.05). Furthermore, in quinolinone-treated cells, the expression levels of p-PI3K, c-Myc and p-AKT were much lower than those in untreated cells (p < 0.05). Quinolinone also downregulated the expressions of MMP-2 and MMP-9, while it upregulated p21 expression in SNU-5 and SGC-7901 cells.Conclusion: Quinolinone suppresses the growth of SNU-5 and SGC-7901 gastric cancer cells via cell cycle arrest, induction of apoptosis and downregulation of the expressions of c-Myc and metalloproteinases. Thus, quinolinone may be developed as a potential drug candidate for the treatment of gastric cancer. Keywords: Gastric cancer, Apoptosis, Metalloproteinases, Phosphorylatio

Accumulation of cinnamic acid and vanillin in eggplant root exudates and the relationship with continuous cropping obstacle

The contents of cinnamic acid and vanillin in eggplant root exudates and soil were determined by HPLC. The results showed that cinnamic acid and vanillin might remain in soil after the root of eggplant is released. With the extending growth stage and planting year of eggplant, the contents in root exudates, rhizosphere and continuous cropping soil increased. In bioassay and field studies, the allelopathy of cinnamic acid and vanillin to the verticillium wilt (V. dahliae) and the eggplant was observed, and when the concentration of cinnamic acid or vanillin was at 1 and 4mmol ⇦ -1, it inhibited the eggplant growth, while the occurrence of verticillium wilt was promoted. A high concentration of cinnamic acid and vanillin caused eggplant autotoxicity and increased the risk of disease infection, which finally led to continuous cropping obstacle.Keywords: Cinnamic acid, vanillin, root exudates, soil, verticillium wilt, continuous cropping obstacl

Sex-specific competition differently regulates ecophysiological responses and phytoremediation of Populus cathayana under Pb stress

Lead (Pb) contamination seriously threatens agroforestry production and safety. We aim to determine the interactive influence of Pb and sexual competition on the growth performance, photosynthetic and biochemical traits, ultrastructure and phytoremediation-related parameters of males and females. In the present study, eco-physiological responses and phytoremediation traits of Populus cathayana females and males were evaluated under interactive treatments of Pb and competition. There were significant sex-specific competition effects on biomass partition, photosynthetic activities, carbohydrate contents, nitrogen and phosphorus use efficiencies, ultrastructure and phytoremediation under Pb stress. When competition within the same sex was compared, females were more sensitive to Pb stress, while males possessed greater Pb contents, and a higher bioconcentration factor and tolerance index. Under inter-sexual competition, males alleviated competition effects through greater Pb absorption, and lower photosynthetic rates, nutrient use efficiencies and biomass accumulation. Moreover, Pb stress altered competition intensities of both sexes. Sex-specific competition and neighbor effects may regulate responses and phytoremediation under heavy metal stress in dioecious plants. In the future, more attention should be paid on the effects of inter- and intra-sexual competition on dioecious species in the process of forestation and restoration of contaminated soil.Peer reviewe

Correlation between resistance of eggplant and defense-related enzymes and biochemical substances of leaves

14 eggplant cultivars were inoculated by Verticillium dahliae to screen their resistance against verticillium wilt. The resistances were shown as the disease incidence and disease index, and eggplant cultivars were classified into resistant type (R), moderate resistant type (MR), tolerant type (T), moderate susceptible (MS) and susceptible type (S), according to the final disease index. To find out the correlated physiological and biochemical indexes for evaluating the resistance of eggplant to verticillium wilt, the activities of defense-related enzymes, and the contents of some biochemical substances of leaves were investigated. The results show that the activities of polyphenol oxidase (PPO) and phenylalanine ammonia lyase (PAL) were significantly positively correlated with resistance (P <0.01) and the resistance was significantly positively correlated with the activity of peroxidase (POD) and the content of total chlorophyll (P<0.05), but significantly negatively correlated with the relative electric conductivity and the content of malondialdehyde (MDA) (P<0.05). The correlations between resistance and catalase (CAT) activity, the contents of sucrose, soluble protein and proline, were not detected.Keywords: Verticillium wilt, eggplant, disease resistance, defense-related enzyme, biochemical substanc

Electron Density Dependence of in-plane Spin Relaxation Anisotropy in GaAs/AlGaAs Two-Dimensional Electron Gas

We investigated the spin dynamics of two-dimensional electrons in (001) GaAs/AlGaAs heterostructure using the time resolved Kerr rotation technique under a transverse magnetic field. The in-plane spin lifetime is found to be anisotropic below 150k due to the interference of Rashba and Dresselhaus spin-orbit coupling and D'yakonov-Perel' spin relaxation. The ratio of in-plane spin lifetimes is measured directly as a function of temperature and pump power, showing that the electron density in 2DEG channel strongly affects the Rashba spin-orbit coupling.Comment: 3 pages, 2 figure

Forecasting N2O emission and nitrogen loss from swine manure composting based on BP neural network

Nitrogen loss and greenhouse gas emission during compost will cause secondary pollution and waste nutrients. To address this issue, a predictive model was set up to obtain a clear knowledge of the N2O emission and nitrogen loss from swine manure composting. This paper collected 68 group data from 11 published papers about pig manure composting N2O emission and total nitrogen loss. Select 4 indexes were taken as predicted indexes include aeration rate, moisture content, C/N, and the amount of superphosphate to establish a BP neural network for forecasting the N2O emission and total nitrogen loss from composting. The analyses show that the mean error of N2O emission forecasting model is 1.17; the value of MAPE is 138.85%. As for nitrogen loss, the mean error is 24.72 and the mean absolute percentage error is 11.06%. Compare to the traditional linear regression, the BP neural network model has good accuracy on forecasting N2O emission and TN loss from manure composting. BP neural network has considerable application prospect in forecast nitrogen loss and greenhouse gas emission from composting

Epidemiology and immunoprotection of nephropathogenic avian infectious bronchitis virus in southern China

<p>Abstract</p> <p>Background</p> <p>In last three years, 96 suspected poultry farms from different provinces in China were diagnosed for avian infectious bronchitis (IB) survey. Finally, 221 IBV strains were confirmed by dwarf embryo test and RT-PCR assay. By virus recovery trials, 187 of the isolates caused the birds died or distressed from nephritis, which was accordant with the clinical record.</p> <p>Results</p> <p>Based on epidemiology analysis of recent field isolates of nephropathogenic IB in vaccinated farms in China, YL6 strain were used for vaccination and evaluated by antibody titer and challenge tests. The immunoprotection test indicated that the practical application of vaccine based on the recent field strains could finely facilitate controlling the nephropathogenic IB.</p> <p>Conclusions</p> <p>Our study was aim at setting a guide for safeguard against nephropathogenic IBV-caused disease in China.</p