Identification and Expression of Several Circular RNAs and Knockdown of hsa_circ_0005556 Exerts Oncogenic Functions by miR-767-5p in Gastric Cancer

作者：Hanke Geng, Kaixuan Li, Qi Pan, Shaohui Tao, Chunjuan Li, Haiwei Zhao, Xiaojun Zhao · 发表于：Medical Science Monitor · 年份：2020 · DOI：10.12659/msm.921163 · 被引用次数：6 · 研究领域：Circular RNAs in diseases、MicroRNA in disease regulation

BACKGROUND Gastric cancer (GC) remains one of the most fatal digestive cancers in the world; nevertheless, its etiology remains vague. With the development of bioinformatics analysis, numerous circular RNAs (circRNAs) have been found to be dysregulated in GC. However, the functions of a large portion of dysregulated circRNAs in GC need further validation. In this study, we aimed to validate the biological functions of circ_0005556, which was previously identified to be dysregulated in GC. MATERIAL AND METHODS Levels of circRNAs and miRNAs in GC tissues and cells were estimated by qRT-PCR. The target miRNAs of circ_0005556 were predicted by bioinformatics methods. The interplay between circ_0005556 and miR-767-5p was validated by dual-luciferase reporter and circRNA immunoprecipitation assays. The effects of circ_0005556 and miR-767-5p on GC cell viability, apoptosis, migration, and invasion were assessed by MTT, flow cytometry, wound-healing and in vitro transwell experiments, respectively. RESULTS The upregulation of circ_0005556 was validated by qRT-PCR in GC tissues and cells, and a higher circ_0005556 level indicated a poorer prognosis. miR-767-5p was demonstrated to target circ_0005556 in GC cells, and a negative correlation was found between their expression levels in GC tissues. Knockdown of circ_0005556 promoted miR-767-5p expression in GC cells. Knockdown of circ_0005556 was revealed to repress GC cell viability, invasion, and migration and to promote GC cell apoptos...