Differential expression of miR-21, miR-222, and Let-7b in serum and follicular fluid of polycystic ovary syndrome: Correlation with biochemical parameters

Abstract

BackgroundPolycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age. Recently, it was discovered that microRNAs (miRNAs), which circulate freely in the circulation or biofluids, have diagnostic or prognostic potential. The current study looked at the levels of expression of three miRNAs in the serum and follicular fluid (FF) of PCOS patients and healthy women. MethodWe have shortlisted the most studied miRNAs—miR-21, miR-222, and Let-7b—from the previous literature, followed by individual quantification using real-time polymerase chain reaction (PCR). ResultsThe present study results showed differences in the expression of miR-21, miR-222, and Let-7b in PCOS patients compared to controls. The area under the receiver operating characteristic (ROC) area under the curve (AUC) for miR-21, miR-222, and Let-7b was 0.70, 0.65, and 0.75 in serum and 0.55, 0.66, and 0.59 in FFs, respectively. The combined ROC of the three miRNAs showed an AUC 0.86 for serum and 0.62 for FF samples. miR-21 showed a positive correlation with body mass index (BMI), and luteinizing hormone (LH) level; miR-222 showed a positive correlation with LH, fasting blood sugar (FBS), and 2-h plasma glucose (PG); while anti-mullerian hormone (AMH), age, erythrocyte sedimentation rate (ESR) and 2-h PG were found to be negatively correlated with Let-b expression. Regression analyses showed a negative association of miR-21 with menarche, progesterone, menses, and antral follicle count (AFC), while serum miR-222 was associated with BMI and age. Let 7-b had a negative association with serum, oocytes, and the LH/FSH ratio. Bioinformatics indicates their predicted targets are potentially involved in microRNA in cancer, diabetes, the P53 signaling pathway, prolactin signaling, the Hippo signaling pathway, Ras signaling, and pathways in cancer. ConclusionThe study found that serum Let-7b, miR-222, and miR-21 were differentially expressed in PCOS patients, suggesting potential involvement in the pathogenesis or progression of PCOS.