MiR-10b Directly Targets ZEB1 and PIK3CA to Curb Adenomyotic Epithelial Cell Invasiveness via Upregulation of E-Cadherin and Inhibition of Akt Phosphorylation.

BACKGROUND/AIMS: Adenomyosis is a disease in which ectopic endometrial glands and stromal cells appear in the uterine myometrium. Despite its prevalence, the molecular mechanisms involved in the development of adenomyosis are largely unknown. The aim of this study was to investigate the role of miR-10b and its target genes ZEB1 and PIK3CA in adenomyosis.

METHODS: 1387 miRNAs in human normal endometrium and ectopic endometrial lesions of adenomyosis using a microarray screen assay. The significant differential expression of 10 miRNAs was confirmed by qRT-PCR. The expression of miR-10b in endometrial epithelial cells isolated from normal endometrium and paired eutopic and ectopic endometrium of adenomyosis was measured by qRT-PCR. Subsequently, the targets of miR-10b were predicted by bioinformatics and confirmed using a luciferase assay, and the mRNA and protein expression of ZEB1 and PIK3CA were assessed in the endometrium or endometrial epithelial cells by qRT-PCR and western blotting or immunohistochemical analysis. Cell migration and cell invasion of endometrial epithelial cells with different treatments by Transwell assays. The expression of p-AKT, Akt and E-cadherin proteins was determined by Western blot analysis.

RESULTS: MiR-10b expression was significantly downregulated in both adenomyotic lesions and adenomyotic epithelial cells. MiR-10b overexpression in adenomyotic epithelial cells inhibited cell migration and invasion. We then demonstrated that miR-10b directly targets the 3'-UTRs of ZEB1 and PIK3CA, and downregulates ZEB1 and PIK3CA in adenomyotic epithelial cells, leading to increased E-cadherin expression and decreased Akt phosphorylation.

CONCLUSIONS: miR-10b directly targets ZEB1 and PIK3CA to curb adenomyotic epithelial cell invasiveness via upregulation of E-Cadherin and inhibition of Akt phosphorylation.