Suppressive Effect Of MiR-506in Migration Of Gastric Cancer Cells

Objective:Invasion and metastasis are important biological characteristics of malignant tumors, epithelial-mesenchymal transition (EMT) is an important mechanism of tumor metastasis. Recent investigations indicated that microRNA plays a key role in the process of EMT. The aim of current study is to confirm that miR-506regulate EMT of gastric cancer cells mediated by Ets-1/MMP9, the possible mechanism of invasion and metastasis, which would provide theoretical basis for new target treatment of gastric cancer.Methods:●Expression of miR-506in different stages of gastric cancer, normal gastric tissue and seven gastric cancer cell lines (BGC-823, AGS, HGC-27, KatoⅢ, SGC-7901, MKN45and MGC-803) was measured by real-time PCR.●Among all the gastric cancer cell lines, BGC-823cell line was transfected with miR-506-inhibitor and SGC-7901cell line was transfected with miR-506-mimic, non-targeting sequence as negative control, and take them as experimental models. Northern blot was performed to detect the expression level of miR-506.●The invasion and migration ability of the cells were examined by transwell assay, scratche healing assay and three-dimensional cell culture.●Use Westernblotting to analyze the expression of E-cadherin and vimentin after suppression or over-expression of miR-506.●Targetscan online was used to predict the target genes of miR-506.●Luciferase reporter assay was used to certify the binding between Ets-1 mRNA of the3’UTR region and miR-506.●Use Westernblotting to analyze the expression of Ets-1, MMP9after suppression and over-expression of miR-506.Results:●Compared with normal tissue, miR-506was reduced in gastric cancer. With the increase in stages, miR-506levels decreased gradually. The expression of miR-506in all seven gastric cancer cell lines were decreased relatively high expression in BGC-823cells and low in SGC-7901cells.●Northern blot showed that miR-506expression in BGC-823cell transfected with miR-506inhibitor was significantly decreased, while in SGC-7901cell transfected with miR-506mimics was significantly increased compared with the cells of non-targeting sequence groups.●Transwell chamber assay, scratches experiment and3D cell culture indicated that miR-506can inhibit the invasion and migration of gastric cancer.●Westernblotting indicated that miR-506can inhibit EMT of gastric cancer.●Targetscan online predicted that Ets-1mRNA of the3’UTR region can binding with miR-506.●A luciferase reporter gene assay showed that miR-506can bind Ets-1mRNA3’UTR directly and reduce Ets-1mRNA expression.●miR-506can regulate the expression of Ets-1and MMP-9.Conclusions:●miR-506might regulate expression of MMP9mediated by Ets-1.●miR-506can inhibit EMT, thereby inhibiting invasion and metastasis of gastric cancer.