Endometriosis, infertility and MicroRNA's: A review.

The review aims to explore circulating small non- coding regulatory Ribonucleic Acids (miRNA) as biomarkers of endometriosis; a reproductive age group disorder. miRNA are linked with genetic, epigenetic and angiogenic factors, hormones, cytokines, chemokines, oxidative stress (OS) markers, mediators of inflammation, hypoxia, angiogenesis and altered immune system contributing to the pathogenesis of endometriosis. Hormonal imbalance occurs by decreased levels of miRNAs -23a and miRNAs -23b and increase in miRNAs -:135a, 135b, 29c and 194-3p. Angiogenesis by vascular endothelial growth factor is attributed to increased miRNAs -126, miRNAs -210, miRNAs -21, miRNAs -199a-5p and miRNAs 20A. OS upregulates miRNAs -302a by increased levels of Tumor Necrosis factor (TNF)-α, TNF- β and Interleukin -1β. Upregulation of miRNAs -199a and miRNAs -16 promotes inflammation and cell proliferation in the endometriotic lesions. The gold standard to diagnose endometriosis is laparoscopy, yet miRNA can be validated as diagnostic tool for detection, progression and prevention of endometriosis in large, independent cohorts of women, with and without endometriosis.