Downregulation of miR­7 and miR­153 is involved in Helicobacter pylori CagA induced gastric carcinogenesis and progression.

Helicobacter pylori (H. pylori) infection plays a pivotal role in the development of gastric cancer (GC). However, the association between aberrant microRNAs (miRNAs/miRs) expression and H. pylori­induced GC remains poorly understood. The present study reported that repeated infection of H. pylori caused the oncogenicity of GES­1 cells in BALB/c Nude mice. miRNA sequencing revealed that both miR­7 and miR­153 were significantly decreased in the cytotoxin­associated gene A (CagA) positive GC tissues and this was further confirmed in a chronic infection model of GES­1/HP cells. Further biological function experiments and in vivo experiments validated that miR­7 and miR­153 can promote apoptosis and autophagy, inhibit proliferation and inflammatory response in GES­1/HP cells. All the associations between miR­7/miR­153 and their potential targets were revealed via bioinformatics prediction and dual­luciferase reporter assay. Particularly, downregulation of both miR­7 and miR­153 obtained an improved sensitivity and specificity in diagnosing H. pylori (CagA+)­induced GC. The present study identified that the combination of miR­7 and miR­153 may be regarded as novel therapeutic targets in H. pylori CagA (+)­associated GC.