title: microRNA-449a functions as a tumor-suppressor in gastric adenocarcinoma by targeting Bcl-2.
abstract: microRNAs (miRNAs or miRs) may function as oncogenes or tumor suppressors. The present study identified that miR-449a was downregulated in human gastric cancer. The overexpression of miR-449a inhibited gastric adenocarcinoma cell growth and promoted cell apoptosis in the MGC-803 and SGC-7901 gastric adenocarcinoma cell lines. Subsequently, Bcl-2 was identified as a potential miR-449a target by bioinformatics analysis. It was also shown that Bcl-2 was negatively regulated by miR-449a at the post-transcriptional level, via a specific target site within the 3'-untranslated region (3'UTR), by luciferase reporter assay. The expression of miR-449a induced cell apoptosis, as observed by TdT-mediated dUTP nick end labeling and caspase 3/7 assays, and was rescued by Bcl-2 expression. Therefore, these observations indicate that miR-449a acts as a tumor suppressor by targeting the Bcl-2 gene and that it promotes gastric adenocarcinoma cell apoptosis via Bcl-2. The findings of this study contribute to or current understanding of the functions of miR-449a in gastric adenocarcinoma.
authors.affiliation: Department of Gastroenterology, Xi'an First Hospital, Xi'an, Shaanxi 710002, P.R. China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wei
authors.forename: Ying
authors.initials: Y
authors.lastname: Song
authors.forename: Yonghong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Mingjun
authors.initials: M
authors.lastname: Hu
keywords: Bcl-2; apoptosis; caspase 3; caspase 7; gastric adenocarcinoma; miR-449a