miRNA‑34a‑5p downregulation of VEGFA in endometrial stem cells contributes to the pathogenesis of endometriosis

: Endometrial-derived stem cells (EnSCs) serve an important role in the development of endometriosis via retrograde menstruation. Abnormal expression of miRNAs in EnSCs is involved in the etiology of endometriosis, however, the mechanisms remain unclear. The aim of the present study was to investigate the expression of miR‑34a‑5p and VEGFA in endometrial samples from patients with or without endometriosis, and then examine the underlying mechanism of microRNA‑34a‑5p regulation of VEGFA in EnSCs. Endometrial samples from patients with or without endometriosis were collected, and miR‑34a‑5p expression in the two groups was measured using RT‑PCR. Human endometrial‑derived stem cells (hEnSCs) were isolated from these endometrial samples, and hEnSCs were transfected with the miR‑34a‑5p mimics or control miRNAs. qPCR and western blotting were performed to assess the effects of miR‑34a‑5p on the expression of VEGFA in hEnSCs, and cell growth was assessed by an MTT assay. miR‑34a‑5p was significantly downregulated in patients with endometriosis when compared with that of those without endometriosis. VEGFA expression levels in hEnSCs with an overexpression of miR‑34a‑5p were significantly reduced when compared with those in the negative control (P<0.01). In addition, the upregulation of miR‑34a‑5p suppressed EnSCs proliferation by targeting the 3' untranslated region of VEGFA. miR‑34a‑5p provides a novel avenue for the understanding of the development of endometriosis, and may facilitate the development of potential therapeutics against endometriosis.