RESUMEN
The anti-malarial drug, artemisinin, is quite expensive as a result of its slow content in Artemisia annua. Recent investigations have suggested that genetic engineering of A. annua is a promising approach to improve the yield of artemisinin. In this study, the transgenic A. annua strain GYR, which has high artemisinin content, was evaluated in an environmental release trial. First, GYR plants were compared with the wild-type variety NON-GYR, with regard to phenotypic characters (plant height, crown width, stem diameter, germination rate, leaf dry weight, 1000-seed weight, leave shape). Second, stress resistance in the two varieties (salt, drought, herbicide, and cold resistance) was evaluated under different experimental conditions. Finally, gene flow was estimated. The results indicated that there were significant differences in several agronomic traits (plant height, stem diameter, and leave dry weight) between the transgenic GYR and NON-GYR plants. Salt stress in transgenic and control plants was similar, except under high NaCl concentrations (1.6%, w/w). Leaf water, proline, and MDA content (increased significantly) were significantly different. Transgenic A. annua GYR plants did not grow better than NON-GYR plants with respect to drought and herbicide resistance. The two varieties maintained vitality through the winter. Third, gene flow was studied in an environmental risk trial for transgenic GYR. The maximum gene flow frequency was 2.5%, while the maximum gene flow distance was 24.4 m; gene flow was not detected at 29.2 m at any direction. Our findings may provide an opportunity for risk assessment in future commercialization of transgenic A. annua varieties.
Asunto(s)
Antimaláricos/metabolismo , Artemisia annua/genética , Artemisininas/metabolismo , Regulación de la Expresión Génica de las Plantas , Hojas de la Planta/genética , Plantas Modificadas Genéticamente , Adaptación Fisiológica/genética , Antimaláricos/aislamiento & purificación , Artemisia annua/metabolismo , Artemisininas/aislamiento & purificación , Frío , Sequías , Flujo Génico , Ingeniería Genética , Germinación/genética , Calor , Malondialdehído/metabolismo , Fenotipo , Hojas de la Planta/metabolismo , Prolina/metabolismo , Salinidad , Estrés FisiológicoRESUMEN
The aim of the present study was to investigate the clinical significance of microRNA-218 (miR-218) in gastric cancer. We enrolled 112 patients having undergone surgery for gastric cancer between May 2008 and June 2014. Expression of miR-218 was determined by real-time quantitative reverse transcription-polymerase chain reaction. Survival curves were plotted using the Kaplan-Meier method and compared by the log-rank test. We found that miR-218 expression was significantly downregulated in gastric cancer tissues compared to adjacent normal tissues (P < 0.001). Low miR-218 expression was significantly associated with tumor differentiation (P < 0.001), depth of tumor invasion (P = 0.006), and tumor node metastasis stage (P < 0.001). Kaplan-Meier survival analysis revealed that patients with low miR-218 levels showed significantly lower 5-year overall survival than those demonstrating high expression (P = 0.04). Multivariate Cox regression analyses indicated that low miR-218 expression constitutes an independent molecular biomarker for prediction of poor overall survival of gastric cancer patients (hazard ratio = 3.187, 95% confidence interval = 1.551-8.365, P = 0.037). In conclusion, miR-218 was remarkably downregulated in gastric cancer tissues and may serve as a prognostic biomarker for patients suffering from this disease.
Asunto(s)
Biomarcadores de Tumor/genética , MicroARNs/genética , Neoplasias Gástricas/genética , Anciano , Biomarcadores de Tumor/metabolismo , Regulación hacia Abajo , Femenino , Humanos , Metástasis Linfática , Masculino , MicroARNs/metabolismo , Persona de Mediana Edad , Neoplasias Gástricas/patologíaRESUMEN
To ensure the implementation of genetically modified organism (GMO)-labeling regulations, an event-specific detection method was developed based on the junction sequence of an exogenous integrant in the transgenic carnation variety Moonlite. The 5'-transgene integration sequence was isolated by thermal asymmetric interlaced PCR. Based upon the 5'-transgene integration sequence, the event-specific primers and TaqMan probe were designed to amplify the fragments, which spanned the exogenous DNA and carnation genomic DNA. Qualitative and quantitative PCR assays were developed employing the designed primers and probe. The detection limit of the qualitative PCR assay was 0.05% for Moonlite in 100 ng total carnation genomic DNA, corresponding to about 79 copies of the carnation haploid genome; the limit of detection and quantification of the quantitative PCR assay were estimated to be 38 and 190 copies of haploid carnation genomic DNA, respectively. Carnation samples with different contents of genetically modified components were quantified and the bias between the observed and true values of three samples were lower than the acceptance criterion (<25%) of the GMO detection method. These results indicated that these event-specific methods would be useful for the identification and quantification of the GMO carnation Moonlite.