A novel circular RNA circ_HN1/miR-628-5p/Ecto-5’-nucleotidase competing endogenous RNA network regulates gastric cancer development

The competing endogenous RNA (ceRNA) activity of circular RNAs (circRNAs) has been implicated in the development of gastric cancer. Here, we sought to explore the ceRNA function of circRNA Jupiter microtubule associated homolog 1 (circ_HN1) in gastric tumorigenesis. Circ_HN1, microRNA (miR)-628-5p, and NT5E expression levels were quantified by qRT-PCR and western blot. Dual-luciferase reporter assays were used to assess the direct relationship between miR-628-5p and circ_HN1 or NT5E. Our data showed that circ_HN1 expression was enhanced in human gastric cancer. Depletion of circ_HN1 impeded cell proliferation, spheroid formation, invasion, and migration and promoted apoptosis in vitro, as well as diminished tumor growth in vivo. NT5E was a downstream effector of circ_HN1 function. NT5E was targeted and inhibited by miR-628-5p through the perfect complementary site in NT5E 3ʹUTR, and circ_HN1 affected NT5E expression through miR-628-5p competition. Moreover, depletion of miR-628-5p reversed the effects of circ_HN1 silencing on regulating cell functional behaviors. Our findings identify a novel ceRNA network, the circ_HN1/miR-628-5p/NT5E axis, for the oncogenic activity of circ_HN1 in gastric cancer, highlighting circ_HN1 inhibition as a promising targeted treatment against gastric cancer.