Knockdown circZNF131 Inhibits Cell Progression and Glycolysis in Gastric Cancer Through miR-186-5p/PFKFB2 Axis.

Gastric cancer (GC) is a prevalent and heterogeneous malignancy in the digestive system. Increasing studies have suggested that circular RNAs are implicated in GC pathogenesis. This study aimed to explore the biological role and underlying mechanism of circRNA zinc finger protein 131 (circZNF131) in GC. The expression pattern of circZNF131, microRNA-186-5p (miR-186-5p), and 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 2 (PFKFB2) mRNA in GC tissues and cells was detected by quantitative real-time polymerase chain reaction. The stability of circZNF131 was verified using ribonuclease R assay. Functional experiments were performed by colony formation assay for cloning ability analysis, transwell assay and wounding healing assay for cell metastasis, and flow cytometry for cell apoptosis. Glycolysis metabolism was investigated by determining the levels of glucose uptake and lactate production. The protein detection of apoptosis- or glycolysis-associated markers, PFKFB2, and Ki-67 was implemented by western blot or immunohistochemistry. Dual-luciferase reporter assay was conducted to identify the interaction between miR-186-5p and circZNF131 or PFKFB2. The role of circZNF131 on tumor growth in nude mice was investigated via xenograft tumor assay. Expression analysis indicated that circZNF131 was upregulated in GC tissues and cells in a stable structure. Functional analyses showed that circZNF131 knockdown suppressed GC cell colony formation ability, migration, invasion and glycolysis metabolism, and induced cell apoptosis. Mechanically, miR-186-5p was a target of circZNF131, and miR-186-5p could bind to PFKFB2. Rescue experiments presented that miR-186-5p inhibition reversed the effects of circZNF131 knockdown on GC cell growth and glycolysis, and PFKFB2 overexpression abolished the impacts of miR-186-5p restoration on GC cell progression. Moreover, circZNF131 could positively modulate PFKFB2 expression via sponging miR-186-5p. In vivo, circZNF131 knockdown hindered GC tumor growth by regulating the miR-186-5p/PFKFB2 axis. circZNF131 could exert an oncogenic role in GC malignant development through the miR-186-5p/PFKFB2 axis, which might provide novel targets for GC treatment.