Unbiased In Silico Analysis of Gene Expression Pinpoints Circulating miRNAs Targeting KIAA1324, a New Gene Drastically Downregulated in Ovarian Endometriosis

Abstract

Objective: To identify circulating miRNAs associated with ovarian endometriosis (OMA), and to analyze candidate genes targeted by these miRNAs. Methods: Putative regulating miRNAs were identified through an original bioinformatics approach. We first queried the miRWalk 2.0 database to collect putative miRNA targets. Then, we matched it to a transcriptomic dataset of OMA. Moving from gene expression in the tissue to possible alterations in the patient plasma, a selection of these miRNAs was quantified by qRT-PCR in plasma samples from 93 patients with isolated OMA and 95 patients surgically checked as free from endometriosis. Then, we characterized the genes regulated by more than one miRNA and validated them by immunohistochemistry and transfection experiments on endometrial cell primary cultures obtained from endometrial biopsies of 10 women with and without endometriosis with miRNA mimics. Stromal and epithelial cells were isolated and cultured separately and gene expression levels were measured by RT-qPCR. Results: Eight miRNAs were identified by bioinformatics analysis. Two of them were overexpressed in plasma from OMA patients: let-7b-5p and miR-92a-3p (p < 0.005). Three miRNAs, let-7b and miR-92a-3p, and miR-93-5p potentially targeted KIAA1324, an estrogen-responsive gene and one of the most downregulated genes in OMA. Transfection experiments with mimics of these two miRNAs showed a strong decrease in KIAA1324 expression, up to 40%. Immunohistochemistry revealed a moderate-to-intense staining for KIAA1324 in the eutopic endometrium and a faint-to-moderate staining in the ectopic endometrium for half of the samples, which is concordant with the transcriptomic data. Discussion and Conclusion: Our results suggested that KIAA1324 might be involved in endometriosis through the downregulating action of two circulating miRNAs. As these miRNAs were found to be overexpressed, their quantification in plasma could provide a tool for an early diagnosis of endometriosis.

<span data-contrast="auto">Evaluating the Prognostic Potential of CA-125 and miRNA Levels in Endometriosis: A Narrative Review <span data-ccp-props="{">

“…Experiments showed let-7b-5p and miR-92a-3p reduce KIAA1324 expression. The study indicates KIAA1324's involvement in endometriosis, regulated by these miRNAs [71].…”

“…These miRNAs hold promise as potential biomarkers for the early diagnosis and management of these debilitating diseases [70]. Abo et al 2022 studied circulating miRNAs related to ovarian endometriosis (OMA). They found let-7b-5p and miR-92a-3p overexpressed in OMA patients' plasma.…”

Identification of miR-30c-5p microRNA in Serum as a Candidate Biomarker to Diagnose Endometriosis

“…miR-342-3p and miR-125-5p were detected overexpressed in the serum of women with endometriosis [31,56]. Studies in plasma samples suggested miR-185-5p [68], miR-125b-5p [62] and miR-92a-3p [69,70] as good biomarkers of endometriosis. Other studies analyzed the effect of under-or overexpression of miR-185-5p [71], miR-142-3p [72,73] and miR-92a-3p [74] on the phenotype of eutopic and/or ectopic endometrial stromal cells, altering their properties and positioning them as future therapeutic alternatives.…”