Background: Circular RNA (circRNA) has been reported as an important regulator in the development and progression of various carcinomas. However, the role of circRNA_100290 in gastric cancer (GC) is still unclear. This study aimed to investigate the role of circRNA_100290 in GC invasion and metastasis and its possible mechanism.
Methods: The expression of circRNA_100290 in GC cells and tissues were examined using quantitative real-time polymerase chain reaction (qRT-PCR). The role of circRNA_100290 in cell proliferation, migration, and invasion was evaluated on AGS and HGC-27 cell lines in vitro. Bioinformatics tools, dual-luciferase reporter assay, Western blot assay and qRT-PCR were used to explore the downstream pathways of circRNA_100290. The mechanism underlying the regulation of the expression of circRNA_100290 was explored using RNA immunoprecipitation, qRT-PCR, and Western blot assays.
Results: The expression of circRNA_100290 was found significantly upregulated in GC cells and 102 GC tissues, high expression of circRNA_100290 in GC was closely related to Borrmann’s types, lymph node metastasis and tumor-node-metastasis staging. In vitro, knockdown of circRNA_100290 in AGS and HGC-27 cells significantly inhibited cell proliferation, migration, and invasion. Mechanistically, dual-luciferase reporter assay confirmed a direct binding between circRNA_100290 and miR-29b-3p, which targets ITGA11, an oncogene which is closely related to epithelial–mesenchymal transition (EMT). In addition, EIF4A3, one of RNA binding proteins (RBPs), could inhibit the formation of circRNA_100290 via enriching flanking sites of circRNA_100290. Low expression of EIF4A3 in GC was related to a worse prognosis.
Conclusions: Elevated circRNA_100290 in GC promotes cell proliferation, invasion and EMT via miR-29b-3p/ITGA11 axi and might be regulated by EIF4A3. CircRNA_100290 might be a promising biomarker and target for GC therapy.