Overexpression of microRNA‐542‐3p attenuates the differentiating capacity of endometriotic stromal cells

AIM: Endometriosis is defined as the presence of endometrial glandular and stromal cells outside of the uterine cavity. A previous study reported that microRNA (miR)‐542‐3p plays a critical role in eutopic endometrial decidualization. This study aims to clarify the potential role of miR‐542‐3p and the target gene, IGFBP‐1 (insulin‐like growth factor‐binding protein 1), in the impairment of the decidualizing capacity of human ectopic endometrial stromal cells (HEcESCs). METHODS: In vitro analysis of primary undifferentiated and decidualizing human eutopic endometrial stromal cells (HEuESCs) and HEcESCs was conducted. The primary HEuESCs or HEcESCs were expanded in culture and decidualized with 8‐bromo‐cyclic adenosine monophosphate (8‐bromo‐cAMP) and medroxyprogesterone acetate (MPA). RESULTS: The morphological and biological differentiating capacities of the HEcESCs were markedly impaired. In contrast to the HEuESCs, the HEcESCs that were treated with the decidual stimulus retained the mesenchymal phenotype and capacity for migration. The down‐regulation of miR‐542‐3p in the HEcESCs treatment with 8‐bromo‐cAMP and MPA was much weaker than that of the HEuESCs. High expression of miR‐542‐3p led to a significant decrease in the expression of IGFBP1 in the HEcESCs. CONCLUSION: Impairment of the differentiating capacity by the overexpression of miR‐542‐3p could influence the capacity for migration and invasion of endometriotic cells in an ectopic environment.