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.