S. Schäfer

microRNA miR-200b affects proliferation, invasiveness and stemness of endometriotic cells by targeting ZEB1, ZEB2 and KLF4

Endometriosis is characterized by growth of endometrial tissue at ectopic locations. Down-regulation of microRNA miR-200b is observed in endometriosis and malignant disease, driving tumour cells towards an invasive state by enhancing epithelial-to-mesenchymal transition (EMT). miR-200b up-regulation may inhibit EMT and invasive growth in endometriosis. To study its functional impact on the immortalized endometriotic cell line 12Z, the stromal cell line ST-T1b, and primary endometriotic stroma cells, a transient transfection approach with microRNA precursors was employed. Expression of bioinformatically predicted targets of miR-200b was analysed by qPCR. The cellular phenotype was monitored by Matrigel invasion assays, digital-holographic video microscopy and flow cytometry. qPCR revealed significant down-regulation of ZEB1 (P < 0.05) and ZEB2 (P < 0.01) and an increase in E-cadherin (P < 0.01). miR-200b overexpression decreased invasiveness (P < 0.0001) and cell motility (P < 0.05). In contrast, cell proliferation (P < 0.0001) and the stemness-associated side population phenotype (P < 0.01) were enhanced following miR-200b transfection. These properties were possibly due to up-regulation of the pluripotency-associated transcription factor KLF4 (P < 0.05) and require attention when considering therapeutic strategies. In conclusion, up-regulation of miR-200b reverts EMT, emerging as a potential therapeutic approach to inhibit endometriotic cell motility and invasiveness.

miR-142-3p is a novel regulator of cell viability and proinflammatory signalling in endometrial stroma cells.

Endometriosis is associated with severe pelvic pain and reduced fertility. Recently, it has been linked to a dysregulation of microRNAs (miRNAs), which are post-transcriptional regulators of gene expression. The functional effect of dysregulated miR-142-3p expression in endometrial stroma cells was investigated. An increased expression of miR-142-3p resulted in a significantly reduced expression of steroid sulfatase and interleukin-6-coreceptor gp130 as well as reduced interleukin-6-mediated activation of the STAT3-pathway, suggesting an effect of miR-142-3p both on steroid hormone- and cytokine-mediated signalling events. At the functional level, miR-142-3p overexpression significantly reduced cell viability (P ≤ 0.01). miR-142-3p regulation emerges as a future therapeutic strategy for endometriosis.