Circ-ZNF609 promotes carcinogenesis of gastric cancer cells by inhibiting miRNA-145-5p expression

OBJECTIVE: To elucidate the expression pattern and biological function of circular RNA ZNF609 (circ-ZNF609) in gastric cancer (GC). PATIENTS AND METHODS: Circ-ZNF609 expression in GC tissues and adjacent normal tissues (ANT) was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The regulatory effect of circ-ZNF609 on growth and metastasis of GC cells was evaluated through the Cell Counting Kit-8 (CCK-8), colony formation and transwell invasion assay, respectively. GC cell apoptosis influenced by circ-ZNF609 was examined by flow cytometry. The binding between circ-ZNF609 and miRNA-145-5p was verified by the Dual-Luciferase reporter gene assay. Finally, a series of rescue experiments were conducted to explore the mechanism of the circ-ZNF609/ miRNA-145-5p axis in regulating GC progression. RESULTS: QRT-PCR data revealed a higher level of circ-ZNF609 in GC tissues relative to ANT. Identically, circ-ZNF609 was highly expressed in GC cell lines relative to controls. The knockdown of circ-ZNF609 in BGC823 and MGC803 cells suppressed proliferative and invasive abilities. MiRNA-145-5p was predicted to be the target gene of circ-ZNF609 by bioinformatics, and further verified by the Dual-Luciferase reporter gene assay. Rescue experiments showed that miRNA-145-5p knockdown partially reversed the regulatory effect of circ-ZNF609 on growth and metastasis of GC cells. CONCLUSIONS: Ciro-ZNF609 promotes proliferative and invasive abilities of gastric cancer cells by inhibiting miRNA-145-5p expression as a ceRNA, thus accelerating gastric cancer progression.