CircRNA_15430 reduced by Helicobacter pylori infection and suppressed gastric cancer progression via miR-382-5p/ZCCHC14 axis

Abstract

Background Helicobacter pylori (H.pylori, HP) is one of the main causes of gastric cancer (GC). CircRNAs have been reported to play a crucial role in developing many types of cancer. However, the role of circRNAs in the development and progression of HP infected-GC has not been studied.Methods Nuclear and cytoplasmic RNA fractionation and RNA fluorescence in situ hybridization analysis (FISH) assays detected the location of circRNA_15430 in GC cells, and quantitative real-time polymerase chain reaction (qRT-PCR) analyzed circRNA_15430, miR-382-5p and ZCCHC14 expression in GC cell lines and tissues. Colony formation, cell counting kit-8 (CCK-8) and Transwell assays, flow cytometry and laser scanning confocal microscopy examined the function of circRNA_15430 in GC cells. Western blotting detected the protein levels. A dual-luciferase reporter assay monitored whether circRNA_15430 sponges miR-382-5p. Furthermore, circRNA_15430 was analyzed in vivo in tumor growth with nude mice.Results CircRNA_15430 is primarily localized in the cytoplasm of GC cells, and downregulated in the GC cell lines and tissues, and is negatively correlated with the tumor size. Downregulation of circRNA_15430 promotes proliferation, migration and suppresses cell apoptosis and autophagy in GC cells. Mechanically, circRNA_15430 acts as a miR-382-5p sponge, alleviating the inhibitory effect of miR-382-5p on its target ZCCHC14. Knockdown circRNA_15430 enhances tumor growth in vivo. In addition, circRNA_15430 was reduced in HP + gastritis tissues and HP-infected MGC-803 cells, reversing the pro-HP effect on autophagy. Additionally, miR-382-5p was increased in HP + gastritis tissue and HP-infected MGC-803 cells while ZCCHC14 decreased in HP-infected MGC-803 cells. MiR-382-5p reverses the effect of si-ZCCHC14 on autophagosome numbers in MGC-803 cells.Conclusions Therefore, circRNA_15430 plays an inhibitory role in GC and regulates the progression of HP infection-related GC, providing a novel molecular marker for GC therapy.