The Up-Regulation Of LncRNA ELFN1-AS1 Expression Promotes The Proliferation,Migration And Invasion Of Gastric Cancer Cells

Research Background:Gastric cancer(GC)is one of the most life-threatening malignant tumours of the digestive system,with one of the highest morbidity and mortality rates of any cancer in the world.Early diagnosis of GC and treatment with radical surgical resection and adjuvant chemotherapeutic agents are key measures to improve the poor prognosis of GC.Lnc RNAs are a large class of non-coding RNA transcripts with a molecular length of more than 200 nucleotides that regulate the malignant progression of a variety of tumour cells at the transcriptional,post-transcriptional and translational levels by participating in epigenetic modifications,splicing of chromatin gene fragments and expression of protein molecules progression of a variety of tumour cells.It has been demonstrated that lnc RNAs are closely linked to the development of GC and play an important regulatory role in the physiopathological processes of proliferation,migration and invasion of GC cells,and can be used as potential biomarkers for GC diagnosis and targeted therapy.However,the expression and functional mechanism of lnc RNA ELFN1-AS1 in GC tissues are still unclear.Objective:The aim of this paper is to investigate the expression of lnc RNA ELFN1-AS1 in GC tissues and cell lines and its relationship with clinicopathological features and prognosis,and to explore the effects and potential mechanisms of action of ELFN1-AS1 on the proliferation,migration and invasion of GC cells in vitro through cell function assays.Methods:1.GC tissues and corresponding normal paracancerous tissue specimens from radical gastrectomy performed at Xiangya Hospital of Central South University were selected in strict accordance with the inclusion and exclusion criteria,with a time start point of September 2018-September 2020,and detailed clinicopathological data of the included patients were recorded.All patients have signed the informed consent form and the experiment was approved by the Ethics Committee of Xiangya Hospital,Central South University.2.Expression of ELFN1-AS1 in 92 pairs of gastric and paraneoplastic tissues as well as in normal cells(GES-1)and five GC cell lines(AGS,MGC-803,HGC-27,BGC-823 and SGC-7901)was examined using q RT-PCR.3.To analyse the correlation between the expression level of ELFN1-AS1 and the clinicopathological characteristics of GC patients using the chi-square test.4.The relationship between the expression level of ELFN1-AS1 and overall survival of GC patients was analysed using the Kaplan-Meier database.5.After down-regulation of ELFN1-AS1 expression by transfection with si RNA,the altered proliferation,migration and invasion ability of GC cells were detected by CCK-8 assay,scratch assay and Transwell assay.6.Detection of subcellular localization of ELFN1-AS1 in GC cells by FISH fluorescence assay.7.Prediction of mi RNAs that may have targeted binding to ELFN1-AS1 using bioinformatics software and analysis of this prospect.Results:1.The expression of lnc RNA ELFN1-AS1 was significantly elevated in GC tissues in the NCBI and TCGA databases.QRT-PCR showed that ELFN1-AS1 expression was significantly upregulated in GC tissues and cell lines.2.Cardinality experimental analysis showed that high expression of ELFN1-AS1 was significantly associated with progressive clinicopathological features,including depth of tumour infiltration,TNM stage,and degree of tumour differentiation(P < 0.05),and that overall survival time was significantly reduced in patients with high ELFN1-AS1expression(P < 0.05).3.After transfection of si-ELFN1-AS1 into GC cell lines,the expression level of ELFN1-AS1 was significantly down-regulated compared to the transfected si-NC group,and the proliferation,migration and invasion ability of GC cells were diminished.4.Lnc RNA ELFN1-AS1 is mainly distributed in the cytoplasm of GC cells,and the online bioinformatics software predicts that ELFN1-AS1 has a target binding site with mi R-486-3p,and ELFN1-AS1 may act as a "molecular sponge" in the form of ce RNA(competitive endogenous RNA)to promote the malignant progression of GC cells.Conclusion.1.Lnc RNA ELFN1-AS1 was more expressed in GC tissues and cell lines than in paraneoplastic tissues and normal gastric epithelial cells.2.High expression of ELFN1-AS1 was associated with depth of tumour infiltration,TNM stage,degree of tumour differentiation and poorer overall survival in patients with GC.3.ELFN1-AS1 is mainly distributed in the cytoplasm of GC cells,and down-regulation of ELFN1-AS1 expression can inhibit the proliferation,migration and invasion ability of GC cells.