CircFOXO3 functions as a molecular sponge for miR-143-3p to promote the progression of gastric carcinoma via upregulating USP44

Gastric carcinoma (GC) ranks fifth in terms of cancer morbidity and third in cancer-related death worldwide and imposes enormous health and economic burdens. The molecular mechanisms underlying GC formation and progression remain unclear. Our aim was to identify the involvement of circular RNA circFOXO3 in GC, and to determine the underlying mechanisms. In this study, we revealed a stimulatory role of circular RNA circFOXO3 in tumor growth in vivo. CircFOXO3 enhanced GC cell proliferation and migration in vitro and promoted tumor growth of GC cells in vivo. Bioinformatic analysis revealed that circFOXO3 might regulate USP44 expression by specifically binding to microRNA (miR)-143-3p. Existence of circFOXO3-miR-143-3p-USP44 axis in GC cells was confirmed by RNA-binding protein immunoprecipitation, luciferase reporter assay, and an RNA pull-down experiments. All the data indicate that circFOXO3 promotes GC cell proliferation and migration by upregulating USP44 expression via targeting of miR-143-3p.