circZNF609 promotes the proliferation and migration of gastric cancer by sponging miR-483-3p and regulating CDK6.

objectiveTo explore the regulatory effects of circZNF609 on proliferative and migratory capacities of gastric cancer (GC) and its underlying mechanism.

methodsExpression level of circZNF609, CDK6 and miR-483-3p in GC tissues and cells were detected qRT-PCR verification. CCK-8 and transwell assay were conducted the cell viability and migratory capacities of GC cells. Dual luciferase assay was enrolled to confirm the interaction among circZNF609, CDK6 and miR-483-3p. Western blot was used to detect the protein level of CDK6.

resultsExpression levels of circZNF609 were higher in GC patients by qRT-PCR.GC patients with higher expression of circZNF609 were expected to have a higher TNM stage and lower 5-year survival than those with lower expression. ROC curves showed a well diagnostic value of circZNF609 in GC. Treatment of RNase R in GC cells downregulated the expression of ZNF609, whereas circZNF609 expression did not change. Furthermore, cytoplasmic expression of circZNF609 was higher than those of nuclear expression. Besides, biological experiments indicated that overexpression of circZNF609 promoted the proliferative and migratory capacities of GC cells. To demonstrate the underlying mechanism of circZNF609, we found that circZNF609 bound to miR-483-3p, which presented a lower expression in GC tissues than that of paracancerous tissues. Both circZNF609 and miR-483-3p could bind to Ago2, suggesting that circZNF609 may act as a sponge of miR-483-3p. In addition, the effect of overexpressed circZNF609 on cellular behaviors of GC cells were partly reversed by overexpression of miR-483-3p. Bioinformatics suggested that CDK6 has a potential binding site with miR-483-3p. The expression of CDK6 markedly increased in GC tissues and cells, which was negatively correlated with miR-483-3p expression. Dual-luciferase reporter gene results indicated that miR-483-3p could bind to the 3'-UTR of CDK6. Moreover, miR-483-3p downregulated CDK6 at both mRNA and protein levels. Overexpression of miR-483-3p inhibited proliferative and migratory capacities of GC cells, which were reversed by CDK6 overexpression.

conclusionIn summary, the expression of circZNF609 is upregulated in GC. CircZNF609 can be used as the sponge of miR-483-3p to regulate the expression level of CDK6, thus participating in the progression of GC by regulating the proliferative and migratory capacities of GC cells.