Circ_0005758 impedes gastric cancer progression through miR-1229-3p/GCNT4 feedback loop

Circular RNAs (circRNAs) have been reported to have roles in the carcinogenesis of gastric cancer (GC). Circ_0005758 was discovered to be decreased in GC, here, the detailed functions and molecular mechanism of circ_0005758 in GC progression were investigated. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting were used to measure the levels of genes and proteins. The biological functions of circ_0005758 on GC progression were investigated by using in vitro assays, including 5-ethynyl-2'-deoxyuridine (EDU), transwell, tube formation and flow cytometry, and in vivo murine xenograft model. The binding between miR-1229-3p and circ_0005758 or GCNT4 (Glucosaminyl (N-Acetyl) Transferase 4) was confirmed using dual-luciferase reporter assay and pull-down assay. Circ_0005758 expression was decreased in GC tissues and cells, re-expression of circ_0005758 induced apoptosis and suppressed proliferation, migration, invasion and angiogenesis in GC cells in vitro, and impeded xenograft tumor growth in nude mice. Mechanistically, circ_0005758 sequestered miR-1229-3p to release GCNT4 expression, indicating the circ_0005758/miR-1229-3p/GCNT4 competing endogenous RNA (ceRNA) network GC cells. Besides, an increased miR-1229-3p level and a decreased GCNT4 expression were observed in GC. Rescue experiments demonstrated that miR-1229-3p up-regulation or GCNT4 down-regulation attenuated the anticancer effects of circ_0005758 re-expression on GC cells. Circ_0005758 acts as a tumor suppressor to impede gastric cancer progression via miR-1229-3p/GCNT4 axis, implying that therapeutic targeting of circ_0005758 may better to prevent gastric cancer.