A critical appraisal of the circulating levels of differentially expressed microRNA in endometriosis†

Plasma microRNA expression in adolescents and young adults with endometriosis: the importance of hormone use

Introduction

Prior studies have investigated the diagnostic potential of microRNA (miRNA) expression profiles for endometriosis. However, the vast majority of previous studies have only included adult women. Therefore, we sought to investigate differential expression of miRNAs among adolescents and young adults with endometriosis.

Methods

The Women's Health Study: from Adolescence to Adulthood (A2A) is an ongoing WERF EPHect compliant longitudinal cohort. Our analysis included 64 patients with surgically-confirmed endometriosis (96% rASRM stage I/II) and 118 females never diagnosed with endometriosis frequency matched on age (median = 21 years) and hormone use at blood draw. MicroRNA measurement was separated into discovery (10 cases and 10 controls) and internal replication (54 cases and 108 controls) phases. The levels of 754 plasma miRNAs were assayed in the discovery phase using PCR with rigorous internal control measures, with the relative expression of miRNA among cases vs. controls calculated using the 2-ΔΔCt method. miRNAs that were significant in univariate analyses stratified by hormone use were included in the internal replication phase. The internal replication phase was split 2:1 into a training and testing set and utilized FirePlex miRNA assay to assess 63 miRNAs in neural network analyses. The testing set of the validation phase was utilized to calculate the area under the curve (AUC) of the best fit models from the training set including hormone use as a covariate.

Results

In the discovery phase, 49 miRNAs were differentially expressed between endometriosis cases and controls. The associations of the 49 miRNAs differed by hormone use at the time of blood draw. Neural network analysis in the testing set of the internal replication phase determined a final model comprising 5 miRNAs (miR-542-3p, let-7b-3p, miR-548i, miR-769-5p, miR-30c-1-3p), yielding AUC = 0.77 (95% CI: 0.67-0.87, p < 0.001). Sensitivity in the testing dataset improved (83.3% vs. 72.2%) while the specificity decreased (58.3% vs. 72.2%) compared to the training set.

Conclusion

The results suggest that miR-542-3p, let-7b-3p, miR-548i, miR-769-5p, miR-30c-1-3p may be dysregulated among adolescent and young adults with endometriosis. Hormone use was a significant modifier of miRNA dysregulation and should be considered rigorously in miRNA diagnostic studies.

Over-expression of mir-181a-3p in serum of breast cancer patients as diagnostic biomarker

BACKGROUND

Recently, the significance of epigenetics, particularly in breast cancer (BC), has become increasingly recognized. MicroRNAs (miRNAs), as an epigenetic factor, are offering valuable insights into various aspects of BC, such as its origins and clinical features. Therefore, studying the disruption of specific miRNAs through microarray and RNA-seq techniques is considered useful.

METHODS AND MATERIALS

We analyzed two microarray datasets (GSE106817 and GSE113486) in order to discover dysregulated miRNAs in the serum of BC patients. Subsequently, RNA-seq analysis was employed on the TCGA data. Two miRNAs, mir-450a-5p and mir-181a-3p, as novel miRNAs in BC studies, were selected for assessment in the serum of 100 BC patients versus 100 healthy female participants. The quantities of the miRNAs described above were determined through the utilization of RT-qPCR. Furthermore, ROC curve assessments were conducted for each individual miRNA. Next, an assessment was conducted to determine the prognostic significance of these miRNAs.

CONCLUSIONS

In summary, the utilization of microarray and RNA-seq analysis techniques has demonstrated that mir-450a-5p and mir-181a-3p exhibit elevated expression levels in the serum of BC patients. However, it is noteworthy that only mir-181a-3p displayed clinical dysregulation, as confirmed by RT-PCR findings. These miRNAs have been found to play a crucial role in modulating essential cellular processes and biological functions that contribute to cancer development. Furthermore, noteworthy outcomes have been observed for mir-181a-3p in relation to diagnostic and prognostic clinical characteristics.

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

The diagnosis of endometriosis by laparoscopy is delayed until advanced stages. In recent years, microRNAs have emerged as novel biomarkers for different diseases. These molecules are small non-coding RNA sequences involved in the regulation of gene expression and can be detected in peripheral blood. Our aim was to identify candidate serum microRNAs associated with endometriosis and their role as minimally invasive biomarkers. Serum samples were obtained from 159 women, of whom 77 were diagnosed with endometriosis by laparoscopy and 82 were healthy women. First, a preliminary study identified 29 differentially expressed microRNAs between the two study groups. Next, nine of the differentially expressed microRNAs in the preliminary analysis were evaluated in a new cohort of 67 women with endometriosis and 72 healthy women. Upon validation by quantitative real-time PCR technique, the circulating level of miR-30c-5p was significantly higher in the endometriosis group compared with the healthy women group. The area under the curve value of miR-30c-5p was 0.8437, demonstrating its diagnostic potential even when serum samples registered an acceptable limit of hemolysis. Dysregulation of this microRNA was associated with molecular pathways related to cancer and neuronal processes. We concluded that miR-30c-5p is a potential minimally invasive biomarker of endometriosis, with higher expression in the group of women with endometriosis diagnosed by laparoscopy.

The prevalence of endometriosis in unexplained infertility: a systematic review

In 15-30% of couples with infertility, no abnormalities are found after the initial diagnostic work-up. The aim of this study was to investigate the prevalence of endometriosis in patients with unexplained infertility undergoing diagnostic laparoscopy in the current era of improved imaging and assisted reproductive technology. A systematic search of PubMed, Embase and Cochrane Central was conducted to identify all studies reporting on pelvic pathologies found by laparoscopy in couples diagnosed with unexplained infertility. Normal ovulatory cycles, normal semen analysis and an infertility period of ≥12 months were the minimum requirements for a study population to be included. The prevalence of endometriosis was 44%, and most lesions were classified as minimal or mild (74%). The prevalence rates of tubal factors and adhesions were 20% and 16%, respectively. The detection rate for pelvic abnormalities was higher in women with prior fertility treatment (75%) compared with women without prior fertility treatment (53%). Despite the significant improvements in imaging for the diagnosis of endometriosis and tubal factors over the last decades, the prevalence rates of endometriosis and tubal abnormalities remain high in patients with unexplained infertility. The high prevalence of endometriosis in this population is important for decision-making in patients who also suffer from pain symptoms suggestive of endometriosis.

Circulating miR-3613-5p but not miR-125b-5p, miR-199a-3p, and miR-451a are biomarkers of endometriosis

OBJECTIVE

This study aimed to assess the utility of circulating miR-125b-5p, miR-199a-3p, miR-451a, and miR-3613-5p as biomarkers of endometriosis.

STUDY DESIGN

Patients with stage III or IV of endometriosis according to the revised American Society of Reproductive Medicine (rASRM) staging classification, as well as control women, were recruited. We created a prospective study conducted on a group of 48 patients (n = 25 controls, n = 24 endometriosis) who had laparoscopic surgery. Blood samples were taken and plasma miRNA levels were measured by quantitative real-time polymerase chain reaction (RT-qPCR) and assessed with AUC and ROC curves.

RESULTS

MiR-451a and miR-3613-5p were significantly decreased in the plasma of endometriosis patients. miR-451a had a receiver-operating characteristic (ROC) area under the curve 0.8283 and miR-3613-5p had a ROC area under the curve 0.7617. The concentration of circulating miR-125b-5p and miR-199-3p did not differ between endometriosis patients and controls. Plasma miRNA levels did not change with BMI, smoking status, fertility problems, or menstrual pain according to the VAS scale (p > 0.05).

CONCLUSION

Circulating miR-451a and miR-3613-5p levels significantly differed between endometriosis and controls. However, the levels of miR-451a were discordant with previous studies. Therefore, miR-3613-5p may have better potential as the endometriosis biomarker. Circulating miR-125b-5p and miR-199a-3p cannot be used as reliable markers of endometriosis.

Effects of selective inhibition of prostaglandin E2 receptors EP2 and EP4 on the miRNA profile in endometriosis

Endometriosis is an estrogen-dependent, progesterone-resistant, chronic inflammatory gynecological disease of reproductive-age women. Two major clinical symptoms of endometriosis are chronic pelvic pain and infertility, which profoundly affect the quality of life in women. Current hormonal therapies to induce a hypoestrogenic state are unsuccessful because of undesirable side effects, reproductive health concerns, and failure to prevent disease recurrence. Prostaglandin E₂ (PGE₂) plays an important role in the survival and growth of endometriotic lesions. MicroRNAs (miRNAs) are small, noncoding RNAs that control gene expressions through multiple mechanisms and have important roles in the pathogenesis of endometriosis. The objective of the present study is to determine the effects of pharmacological inhibition of PGE₂ receptors, EP2 and EP4, on miRNA profile in endometriosis. The novel results collectively indicate that inhibition of PGE₂-EP2/EP4 signaling regulated several miRNA clusters associated with cell adhesion, migration, invasion, survival and growth in cell-specific and the chromosome-specific manner and reverses the epigenetic silencing of proapoptotic miRNAs 15a and 34c in the human endometriotic epithelial and stromal cells and experimental endometriotic lesions. Thus, selective inhibition of EP2/EP4 receptors could emerge as a potential nonsteroidal therapy for endometriosis.

Endometriosis-associated infertility: From pathophysiology to tailored treatment

Despite the clinically recognized association between endometriosis and infertility, the mechanisms implicated in endometriosis-associated infertility are not fully understood. Endometriosis is a multifactorial and systemic disease that has pleiotropic direct and indirect effects on reproduction. A complex interaction between endometriosis subtype, pain, inflammation, altered pelvic anatomy, adhesions, disrupted ovarian reserve/function, and compromised endometrial receptivity as well as systemic effects of the disease define endometriosis-associated infertility. The population of infertile women with endometriosis is heterogeneous, and diverse patients' phenotypes can be observed in the clinical setting, thus making difficult to establish a precise diagnosis and a single mechanism of endometriosis related infertility. Moreover, clinical management of infertility associated with endometriosis can be challenging due to this heterogeneity. Innovative non-invasive diagnostic tools are on the horizon that may allow us to target the specific dysfunctional alteration in the reproduction process. Currently the treatment should be individualized according to the clinical situation and to the suspected level of impairment. Here we review the etiology of endometriosis related infertility as well as current treatment options, including the roles of surgery and assisted reproductive technologies.