Circulating microRNAs as potential biomarkers for endometriosis

Objective: To evaluate whether microRNAs (miRNAs) associated with endometriosis are detectable in the circulation and could serve as potential noninvasive biomarkers for endometriosis. Design: Case-control study. Setting: University hospital. Patient(s): Twenty-four women with endometriosis and 24 women without the disease (controls). Intervention(s): Serum samples collected from women undergoing laparoscopy for endometriosis and other benign gynecologic disease. Main Outcome Measure(s): Total RNA extracted from serum and quantitative reverse-transcription polymerase chain reaction to determine levels of miRNA let-7a-f and miR-135a,b. Result(s): The levels of circulating let-7b and miR-135a were statistically significantly decreased in women with endometriosis compared with controls, and let-7d and 7f showed a trend toward down-regulation. Let-7b expression strongly correlated with serum CA-125 levels and showed the highest area under the curve of 0.691. When the patients were analyzed according to phase of the menstrual cycle, the expression of let-7b, 7c, 7d, and 7e was statistically significantly lower in the women with endometriosis during the proliferative phase. Using a logistic regression model, we evaluated the diagnostic power of differently expressed miRNAs; the combination of let-7b, let-7d, and let-7f during the proliferative phase yielded the highest area under the curve value of 0.929 in discriminating endometriosis from controls. Conclusion(s): Several circulating miRNAs are differentially expressed in the sera of women with endometriosis compared with controls. The combination of serum let-7b, 7d, and 7f levels during the proliferative phase may serve as a diagnostic marker for endometriosis. (C) 2015 by American Society for Reproductive Medicine.