CircRNA_001569 promotes cell proliferation through absorbing miR-145 in gastric cancer

: Gastric cancer severely threatens human life, while its pathogenesis is still unclear. The present study was to explore the potential pathogenic mechanism underlying gastric cancer. Real-time PCR was performed to detect the expression of circRNA_001569 and miR-145; western blot was performed to detect the expression of NR4A2. Cell cycle and apoptosis was determined using flow cytometry, and cell viability was determined using Cell counting kit-8 (CCK-8) assay. Luciferase reporter assay was carried out to validate the relationship between miR-145 and NR4A2. Both circRNA_001569 and NR4A2 were overexpressed in tissues and cells of gastric cancer, while miR-145 was down-regulated. Overexpressed circRNA_001569 significantly increased cell viability, and decreased cell apoptosis, while down-regulated circRNA_001569 dramatically decreased cell viability and promoted cell apoptosis. CircRNA_001569 regulated the expression of miR-145, the effect of pcDNA-circRNA_001569 was abolished by miR-145 mimic and the effect of si-circRNA_001569 was abolished by miR-145 inhibitor. MiR-145 targets NR4A2 to regulate its expression. Overexpressed miR-145 suppressed cell viability and promoted cell apoptosis. Taken together, the present study indicated that overexpressed circRNA_001569 promoted cell viability of gastric cancer through suppressing the expression of miR-145, which was mediated by NR4A2. The research will provide great theoretical basis for further clinical diagnosis and therapy.