| Objective:Gastric adenocarcinoma is the most common malignant tumor of the digestive tract.Its incidence rate is fifth in the human malignant tumor,and the mortality rate is third highest.Micro RNA(miRNA)is a kind of endogenous noncoding RNA with a length of 20-24 nucleotides.Mi RNA plays an important role in the occurrence and development of gastric adenocarcinoma.It is reported that Micro RNA-615-5p(mircro RNA-615-5p,miR-615-5p)plays an important role in a variety of cancers.However,there are few studies on the mechanism of miR-615-5p in gastric adenocarcinoma in the existing literature.The purpose of this paper is to investigate the expression and mechanism of miR-615-5p in gastric adenocarcinoma.Methods:1.The expression of miR-615-5p in 48 cases of gastric adenocarcinoma and their adjacent tissues was detected by q RT PCR,and the correlation between the expression of miR-615-5p and the clinical characteristics of gastric adenocarcinoma was analyzed.2.Take human gastric adenocarcinoma cell lines(BGC,HGC and MGC)and human normal gastric mucosal cell line(GES cell line)as the research objects at the cellular level,and detect the expression of miR-615-5p and IGF2 m RNA in gastric adenocarcinoma cell lines by q RT PCR.3.According to the expression of miR-615-5p in different gastric cancer cells,HGC cells were selected as the overexpression research object,further divided into overexpression control group(transfected with control mimics)and miR-615-5p overexpression group(transfected with miR-615-5p mimics).MGC cells were selected as the knockdown research object,further divided into low expression control group(transfected with control inhibitor)and miR-615-5p low expression group(transfected with miR-615-5p inhibitor).4.Plate clone formation test,wounding healing assay,Transwell migration and invasion test were used to verify the effects of overexpression or knockdown of miR-615-5p on the proliferation,migration and invasion of gastric adenocarcinoma cells.5.Predict the target genes that miR-615-5p may bind by bioinformatics.6.The expression level of target gene IGF2(insulin-like growth factor-2,IGF2)and the levels of PI3K/AKT signal pathway related proteins after transfection of miR-615-5p mimics and inhibitor were detected by Western blot test.7.The effects of co-transfection of miR-615-5p inhibitor and IGF2 si RNA on the proliferation,migration and invasion of gastric adenocarcinoma cells were detected by plate clone formation test,wounding healing assay,Transwell migration and invasion test and Western blot test.8.After co-transfection of miR-615-5p inhibitor and IGF2 small interfering RNA,the levels of PI3K/AKT signal pathway related proteins were detected by Western blot test.Results:1.The expression level of miR-615-5p in gastric adenocarcinoma was significantly lower than that in normal adjacent tissues(P < 0.01).The expression level of miR-615-5p in gastric adenocarcinoma was related to the tumor size and lymph node metastasis of gastric adenocarcinoma(P < 0.01).2.The expression level of miR-615-5p in gastric adenocarcinoma cell line was significantly lower than that in normal gastric mucosal epithelial cells GES.3.Overexpression of miR-615-5p inhibited the proliferation,migration and invasion of gastric adenocarcinoma cells;Knockdown of miR-615-5p promoted the proliferation,migration and invasion of gastric adenocarcinoma cells.4.Bioinformatics predicted that IGF2 was a potential target gene of miR-615-5p.The expression of IGF2 was up-regulated in gastric adenocarcinoma cells and negatively correlated with the expression of mir-615-5p.On the basis of knockdown of miR-615-5p,silencing IGF2 can reverse the promoting effect of knocking down miR-615-5p on the development of gastric adenocarcinoma cells.5.After overexpression of miR-615-5p,the expressions of IGF2,PI3 K,AKT and m TOR proteins were significantly lower than those in miR-615-5p NC group;After knockdown of miR-615-5p,the expressions of IGF2,PI3 K,AKT and m TOR proteins were significantly higher than those in miR-615-5p NC group.After co-transfection with miR-615-5p inhibitor and si-IGF2,the expression levels of IGF2,PI3 K,AKT and m TOR proteins were reversed.Conclusion:The expression of miR-615-5p was significantly down-regulated in gastric adenocarcinoma tissues and cells.Overexpression of miR-615-5p could inhibit the proliferation,migration and invasion of gastric adenocarcinoma cells.In addition,miR-615-5p can inactivate PI3K/AKT/m TOR signal pathway by directly targeting IGF2,thus inhibiting the occurrence and development of gastric adenocarcinoma. |
