Down-Regulation of miR-141 Induced by Helicobacter Pylori Promotes the Invasion of Gastric Cancer by Targeting STAT4

Background: The association between Helicobacter pylori infection and gastric cancer has been identified recently. However, the molecular mechanism remained largely unknown. Methods and Results: We found that miR-141 was decreased in Helicobacter pylori positive specimens (n=75) compared with negative tissues (n=75). The knockdown of miR-141 enhanced the invasion ability of gastric cancer cells; meanwhile, over-expression of miR-141 could inhibit the abilities of gastric cancer cells in vitro. A luciferase assay revealed that miR-141 was directly bound to the 3'-untranslated regions (3'-UTR) of STAT4. STAT4 was found up-regulated at mRNA and protein levels, as shown by qRT-PCR and western blot. Over-expression of STAT4 was used to mimic miR-141 action in the invasion of gastric cancer. Conclusion: MiR-141 may play a pivotal role in controlling gastric cancer invasion through regulating STAT4 and maybe a potential target to treat gastric cancer