Clinical Significance Of Abnormal Expression Of Circular RNA BGN In Gastric Cancer And Its Effect On Biological Behavior Of Gastric Adenocarcinoma Cells

Objective: Based on the results of pre-existing circular RNA(circRNA)expression profiling,a differentially expressed circRNA in gastric cancer was screened to investigate the relationship between the expression level of circRNA in gastric cancer and non-cancerous tissues and clinical pathological factors.The effect of the expression level of the target circRNA on the biological behavior of gastric adenocarcinoma cell lines was preliminarily investigated,and the target miRNA downstream of the target circRNA was predicted.Methods:(1)Based on the results of previous gene chip assays,a circRNA(circBGN)stably up-regulated in gastric cancer was screened,and the target genes of circBGN were predicted by bioinformatics;(2)The expression level of circBGN was verified by qPCR both in gastric cancer and matched non-cancerous tissues,and then correlated with clinicopathological data of gastric cancer patients;(3)siRNA interference was used to down-regulate the expression level of circBGN in gastric cancer cell lines.The effects of down-regulation of circRNA expression on cell biological behavior were investigated by a series of cell function experiments,including cell proliferation assay,cell migration assay and colony formation assay.Result:(1)The circRNA expression profile of gastric cancer showed up-regulated expression of circBGN.The expression profile chip showed that the fold change of circBGN was 3.8982337(P<0.05).192 target miRNAs could be combined with circBGN predicted by GO/Pathway analysis and MiRanda software.(2)Compared with adjacent tissues(normal tissues),circBGN was up-regulated in60% of 143 gastric adenocarcinoma tissue samples,with a change of 32.3±20.64(P<0.0001).The differential expression of circBGN in gastric cancer and matched paracancerous tissues was closely related to serosa invasion(P<0.05).However,there was no statistically significant difference in age,gender,tumor growth site,tumor size,degree of differentiation,lymph node metastasis,distant metastasis,perineural invasion,and vascular invasion in patients with gastric adenocarcinoma.(3)The expression level of circBGN in gastric adenocarcinoma cell lines(SGC-7901 and AGS)were higher than that of normalgastric mucosal epithelial cell line(GES-1)(P<0.05).Down-regulation of circBGN could inhibit the proliferation,migration and colony formation of gastric adenocarcinoma cell lines(SGC-7901 and AGS)(P< 0.05).Conclusion: circBGN is up-regulated in gastric adenocarcinoma tissues and cells,and is associated with lymph node metastasis and serosa invasion.When the tumor invaded the serosa layer,the expression level of circBGN was significantly up-regulated.However,there was no significant correlation with patient age,gender,tumor growth site,tumor size,degree of differentiation,lymph node metastasis,distant metastasis,perineural invasion,and vascular invasion.Down-regulation of circBGN expression can inhibit the proliferation,migration and colony formation of gastric adenocarcinoma cells.circBGN can bind to 192 target miRNAs predicted by bioinformatics.circBGN may be a potential biomarker and drug target for gastric cancer.