| Objectives:Gastric adenocarcinoma is a kind of high incidence malignant tumor.Several long non-coding RNAs(lncRNA)including H19 and HOTAIR have been confirmed to be involved in the development of gastric adenocarcinoma.Based on the pre-stage gastric adenocarcinoma-associated expression profiling of lncRNA microarray,this study is aimed at finding a novel lncRNA associated with gastric adenocarcinoma and clarifying its clinical significance and function.Methods:Based on the previous microarray results of our research team,a novel lncRNA SEMA3B-AS1 which was down-regulated in gastric adenocarcinoma was screened out.The tissue samples from 120 patients with gastric adenocarcinoma who had undergone surgical treatment at General Surgery Department of Fuzhou General Hospital from April 2014 to April 2016 were collected.The expression level of lncRNA SEMA3B-AS1 in gastric adenocarcinoma tissues was verified by real-time quantitative PCR.Combined with postoperative pathological data,the clinical significance of abnormal expression of SEMA3B-AS1 in gastric adenocarcinoma was statistically analyzed.Then lncRNA SEMA3B-AS1 overexpression plasmid vector was constructed and transfected into gastric adenocarcinoma cells via liposome,and through G-418 resistance screening,the gastric adenocarcinoma cell line that stably overexpressed SEMA3B-AS1 was obtained.Furthermore,through a series of cell function assays in vitro,the effects of lncRNA SEMA3B-AS1 overexpression on proliferation,migration,invasion,and apoptosis of gastric adenocarcinoma cells were investigated,using the gastric adenocarcinoma cells stably transfected with empty vector as controls.Results:The relative expression of lncRNA SEMA3B-AS1 in gastric adenocarcinoma tissues was significantly lower than that in corresponding paracancerous tissues.The proportion of down-regulated expression in gastric adenocarcinoma tissues was 76.67%(92/120),and the mean fold-change of down-regulation expression was-7.141(P<0.01).The abnormal expression of SEMA3B-AS1 was closely related to lymph node metastasis(?2=8.453,P=0.004)and vessel invasion(?2=6.069,P=0.014)in gastric adenocarcinoma.In vitro,lncRNA SEMA3B-AS1 overexpression significantly inhibited the proliferation,colony formation,migration,invasion and promoted apoptosis of gastric adenocarcinoma cells BGC-823 and SGC-7901(P<0.05).SEMA3B is a known tumor suppressor gene.SEMA3B expression was significantly down-regulated in gastric adenocarcinoma tissues(mean fold-change-2.700,P<0.01),and was positively correlated with the expression level of IncRNA SEMA3B-AS1(r=0.483,P<0.01).Conclusions:SEMA3B-AS1 is an lncRNA that is down-regulated in gastric adenocarcinoma tissues and has tumor suppressor characteristics.Its differential expression was closely related to lymph node metastasis and vessel invasion.Our study shows that lncRNA SEMA3B-AS 1 may participate in the occurrence and development of gastric adenocarcinoma,and could be used as a potential molecular marker of gastric adenocarcinoma. |
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