Comparative Analysis of Cell-Free miR-205-5p, let-7f-5p, and miR-483-5p Expression in Ovarian Cell Cultures and Plasma Samples of Patients with Ovarian Cancer

Abstract

The term liquid biopsy reveals a non-invasive diagnostic method that might be based on the quantification of cell-free microRNAs in body fluids. However, the identification of candidates for liquid biopsy is challenging. Our aim was to compare the cell-free expression of miR-483-5p, miR-205-5p, and let-7f-5p in ovarian cell cultures and plasma samples of patients with ovarian cancer. Both the intracellular and cell-free expression of miR-205-5p and let-7f-5p proved to be higher in the Estrogen Receptor α (ERα) expressing PEO1 cell-line than in the estrogen non-sensitive A2780. Moreover, the expression of let-7f-5p was up-regulated in response to estradiol exposure that was diminished after the addition of an ERα selective antagonist. MiR-483-5p had lower intracellular and cell-free expression in PEO1. All these miRNAs had detectable expression level in plasma samples, among which miR-205-5p proved to be overexpressed in the plasma samples of patients with ovarian tumors compared to healthy controls and possessed an acceptable diagnostic potential with ROC-AUC 0.683 (95% CI 0.57–0.795). Functional annotation clustering of the target genes of miR-205-5p revealed several clusters involved in cancer development. We suggest that miR-205-5p might be a promising biomarker candidate in ovarian cancer that should be further analyzed in larger sample size.