miR-24-3p Regulates Progression of Gastric Mucosal Lesions and Suppresses Proliferation and Invasiveness of N87 Via Peroxiredoxin 6

Background MicroRNAs, targeting mRNAs of cancer-associated genes, are often aberrantly expressed in human gastric cancer (GC). Aim We have examined the possible role and mechanisms of miRNA regulation of Prdx-6 in the development and progression of H. pylori -related gastric mucosal lesions. Methods First, miR-24-3p was predicted to target Prdx-6, and this negative regulation was validated by luciferase reporter analyses, Western blot, and quantitative RT-PCR. Next, immunohistochemistry and in situ hybridization were performed to detect the Prdx-6 and miR-24-3p expression in tissue microarrays of gastric mucosal lesions. Finally, the miR-24-3p function in GC cell line N87 was examined by MTT, Annexin V-FITC, PI, transwell migration, and Matrigel invasion assays. Results In our study, Prdx-6 expression was negatively regulated by miR-24-3p expression and miR-24-3p interacted with the 3′-untranslated region of Prdx-6 to down-regulate its expression level. In addition, miR-24-3p expression gradually decreased in human gastric specimens from chronic superficial gastritis (CSG) to dysplasia and was upregulated in GC tissues compared with adjacent normal tissues. Contrary to this, Prdx-6 expression showed inverse tendency in the same tissue. More so, expression of miR-24-3p was reduced in samples with H. pylori infection, especially in CSG. Moreover, miR-24-3p was associated with GC lymph nodes and liver metastasis. Gain- or loss-of-function experiments showed that miR-24-3p significantly inhibited N87 cell growth, migration, and invasion and promoted apoptosis, while Prdx-6 reversed these miR-24-3p effects. Conclusions miR-24-3p was identified as a regulator of development and progression of H. pylori -related gastric mucosal lesions.