RÉSUMÉ
Objective To explore the impacts of long non-coding RNA(LncRNA)GNAS antisense RNA1(GNAS-AS1)on the proliferation and migration of gastric cancer(GC)cells by regulating the miR-449a/Notch1 axis.Method Tumor tissue and adjacent tissue samples were collected from 30 patients diagnosed with GC at Sichuan Provincial People's Hospital from September 2013 to September 2017;GC cells AGS were randomly divided into Control group,si-NC group,si-GNAS-AS1 group,si-GNAS-AS1+inhibitor NC group,and si-GNAS-AS1+miR-449a inhibitor group.Real-time fluorescence quantitative PCR method was applied to detect the expres-sion of GNAS-AS1,miR-449a,and Notch1 mRNA;MTT experiments and plate cloning experiments were applied to detect the proliferation;wound healing test was applied to detect cell migration;Transwell experiment was applied to detect cell invasion.Western Blot was applied to detect the expression of Notch1,E-cadherin,Vimentin,and N-cadherin proteins.Double Luciferase reporter gene experiment was applied to verify the relationship between GNAS-AS1 and miR-449a,between miR-449a and Notch1,respectively.Results Compared with adjacent tissues,the expression of GNAS-AS1 and Notch1 mRNA in tumor tissue was increased,the expression of miR-449a was reduced(P<0.05).Compared with the Control group and si-NC group,the expression of GNAS-AS1,OD490 value,number of clones formed,scratch healing rate,number of cell invasions,and the expression of Notch1,Vimentin,and N-cadherin proteins in AGS cells in the si-GNAS-AS1 group reduced,the expression of miR-449a and E-cadherin protein increased(P<0.05).Compared with the si-GNAS-AS1 group and the si-GNAS-AS1+inhibitor NC group,the OD490 value,scratch healing rate,number of cell invasions,Notch1,Vimentin,and N-cadherin expression in the si-GNAS-AS1+miR-449a inhibitor group increased,the expression of miR-449a and E-cadherin protein reduced(P<0.05).GNAS-AS1 targeted and negatively regulated miR-449a expression,while miR-449a targeted and negatively regulated Notch1 expression.Conclusion Silencing GNAS-AS1 may inhibit the expression of Notch1 protein by up-regulating miR-449a,thereby inhibiting the proliferation,migration,and invasion pro-cesses of GC cells.
RÉSUMÉ
An analytical method was developed for the simultaneous extraction and determination of three quaternary ammonium compouds ( QACs) in soil samples using ultrasonic extraction and gas chromatography-mass spectrometry( GC-MS) . The qualitative and quantitative analysis of the three analytes dodecyltrimethyl ammonium chloride ( DTAC) , cetyltrimethyl ammonium bromide ( CTAB) and didodecyldimethyl ammonium chloride ( DDAC) were conducted by application of EI mass spectra and selected ion monioring ( SIM ) . Characteristic ions of the QACs were m/z 58 ( DTAC and CTAB) and m/z 212 ( DDAC) . To achieve optimum extraction efficiency, several impact factors including types of extractants, pH of extraction, concentration of linear alkylbenzene sulfonates ( LAS) , extraction times and content of purification column were investigated. Methanol with pH 3. 5 and 40 μg/L LAS solution were selected as extractant. Soil sample was extracted by treated methanol each 10 mL for 20 min every time. Extract of the soil sample was purified by neutral alumina column with 4 cm in length and 1cm in diameter, and then was determineted by GC-MS. Good linear relationships of all the three QACs were obtained in the range of 0. 02-2. 0 mg/L. The limits of determination (LOD, S/N=3) was 1. 2-4. 5 μg/kg. The method was used to analyse real soil samples ( paddy soil, lateritic red soil, and ore tailings) collected from a mining district in south China. Results of determination exhibited the concerntrations of the three analytes in real soil samples ranged from 0 . 24 mg/kg to 0. 41 mg/kg, and their recoveries ranged from 76% to 113% with relative standard deviations ( RSD) of 1. 1%-12. 9% in three different spiked concentrations of 0. 2, 0. 5 and 1. 0 mg/kg.