Overexpression of miR-21-5p as a potential pathogenesis marker for ovarian endometriosis

Abstract

Abstract Background Endometriosis is a benign gynecological disease characterized by the growth of endometrial cells beyond the uterus, forming endometriotic cyst tissues called ovarian endometriomas. MicroRNAs (miRNAs) are small, non-coding RNAs that epigenetically control the physiological and pathological processes of different diseases, including endometriosis. In this study, we screened the expression levels of 11-selected miRNAs, namely miR-21-5p, miR-200c-3p, miR-19a-3p, miR-203-3p, miR-181b-5p, miR-182-5p, miR-let7a-5p, miR-205-5p, miR-200b-3p, miR-16-5p, and miR-222-3p in ovarian endometriomas relative to eutopic endometrial tissues using quantitative real-time PCR (qPCR). In addition, the level of mRNA expression of lumican (LUM), an extracellular matrix proteoglycan (PG), and a putative target of miR-21-5p was quantified by qPCR. Results Our screening qPCR results showed that 9 miRNAs were upregulated (miR-21-5p, miR-200c-3p, miR-19a-3p, miR-203-3p, miR-181b-5p, miR-182-5p, miR-let7a-5p, miR-205-5p, and miR-200b-3p), whereas 2 miRNAs were downregulated (miR-16-5p and miR-222-3p) in ovarian endometriomas compared to eutopic endometrium. A significant overexpression of miR-21-5p in ovarian endometrioma was further independently verified by qPCR. Using bioinformatics tools, Gene Ontology Kyoto Encyclopedia of Genes and Genomes pathways, and protein–protein interactions, we identified differentially expressed genes and several pathways regulated by miR-21-5p that may contribute to endometriosis progression. Among them, LUM was found to be significantly diminished expressed in ovarian endometriomas compared to eutopic endometrium. Conclusion In conclusion, this study identified miR-21-5p and LUM as potential factors that may contribute to ovarian endometriomas’ pathogenesis.