Cell-free nucleic acids as non-invasive biomarkers of gynecological cancers, ovarian, endometrial and obstetric disorders and fetal aneuploidy

Identification of Mycobacterium tuberculosis Resistance to Common Antibiotics: An Overview of Current Methods and Techniques

Multidrug-resistant tuberculosis (MDR-TB) is an essential cause of tuberculosis treatment failure and death of tuberculosis patients. The rapid and reliable profiling of Mycobacterium tuberculosis (MTB) drug resistance in the early stage is a critical research area for public health. Then, most traditional approaches for detecting MTB are time-consuming and costly, leading to the inappropriate therapeutic schedule resting on the ambiguous information of MTB drug resistance, increasing patient economic burden, morbidity, and mortality. Therefore, novel diagnosis methods are frequently required to meet the emerging challenges of MTB drug resistance distinguish. Considering the difficulty in treating MDR-TB, it is urgently required for the development of rapid and accurate methods in the identification of drug resistance profiles of MTB in clinical diagnosis. This review discussed recent advances in MTB drug resistance detection, focusing on developing emerging approaches and their applications in tangled clinical situations. In particular, a brief overview of antibiotic resistance to MTB was present, referred to as intrinsic bacterial resistance, consisting of cell wall barriers and efflux pumping action and acquired resistance caused by genetic mutations. Then, different drug susceptibility test (DST) methods were described, including phenotype DST, genotype DST and novel DST methods. The phenotype DST includes nitrate reductase assay, RocheTM solid ratio method, and liquid culture method and genotype DST includes fluorescent PCR, GeneXpert, PCR reverse dot hybridization, ddPCR, next-generation sequencing and gene chips. Then, novel DST methods were described, including metabolism testing, cell-free DNA probe, CRISPR assay, and spectral analysis technique. The limitations, challenges, and perspectives of different techniques for drug resistance are also discussed. These methods significantly improve the detection sensitivity and accuracy of multidrug-resistant tuberculosis (MRT) and can effectively curb the incidence of drug-resistant tuberculosis and accelerate the process of tuberculosis eradication.

Agarose amplification based sequencing characterization cell-free RNA in preimplantation spent embryo medium

BACKGROUND

The cell-free RNA (cf-RNA) of spent embryo medium (SEM) has aroused a concern of academic and clinical researchers for its potential use in non-invasive embryo screening. However, comprehensive characterization of cf-RNA from SEM still presents significant technical challenges, primarily due to the limited volume of SEM. Hence, there is urgently need to a small input liquid volume and ultralow amount of cf-RNA library preparation method to unbiased cf-RNA sequencing from SEM. (75) RESULT: Here, we report a high sensitivity agarose amplification-based cf-RNA sequencing method (SEM-Acf) for human preimplantation SEM cf-RNA analysis. It is a cf-RNA sequencing library preparation method by adding agarose amplification. The agarose amplification sensitivity (0.005 pg) and efficiency (105.35 %) were increased than that of without agarose addition (0.45 pg and 96.06 %) by ∼ 90 fold and 9.29 %, respectively. Compared with SMART sequencing (SMART-seq), the correlation of gene expression was stronger in different SEM samples by using SEM-Acf. The cf-RNA number of detected and coverage uniformity of 3' end were significantly increased. The proportion of 5' end adenine, alternative splicing events and short fragments (<400 bp) were increased. It is also found that 4-mer end motifs of cf-RNA fragments was significantly differences between different embryonic stage by day3 spent cleavage medium and day5/6 spent blastocyst medium. (141) SIGNIFICANCE: This study established an efficient SEM amplification and library preparation method. Additionally, we successfully described the characterizations of SEM cf-RNA in preimplantation embryo using SEM-Acf, including expression features and fragment lengths. SEM-Acf facilitates the exploration of cf-RNA as a noninvasive embryo screening biomarker, and opens up potential clinical utilities of small input liquid volume and ultralow amount cf-RNA sequencing. (59).

The Ratio of cf-mtDNA vs. cf-nDNA in the Follicular Fluid of Women Undergoing IVF Is Positively Correlated with Age

Age-related mitochondrial markers may facilitate the prognosis of artificial reproductive technology outcomes. In this report, we present our study concerning the ratio of cf-mtDNA/cf-nDNA, namely the amount of cell-free mitochondrial DNA relative to cell-free nuclear DNA, in the follicular fluid (FF) of women undergoing IVF, aiming to generate a molecular fingerprint of oocyte quality. The values of this ratio were measured and compared among three groups of women (101 in total): (A) 31 women with polycystic ovary syndrome (PCOS), (B) 34 women younger than 36 years, and (C) 36 women older than 35 years of age. Real-time quantitative PCR (qPCR) was performed to quantify the ratio by using nuclear- and mitochondrial-specific primers and analyzed for potential correlation with age and pregnancy rate. Our analysis showed that the level of FF-cf-mtDNA was lower in the group of advanced-age women than in the groups of PCOS and non-PCOS women. Moreover, a significant positive correlation between FF-cf-mtDNA and the number of mature (MII) oocytes was observed. Collectively, the data show that the relative ratio of cf- mtDNA to cf-nDNA content in human FF can be an effective predictor for assessing the corresponding oocyte's age-related performance in IVF.

Advances in liquid biopsy-based markers in NSCLC

Lung cancer is the second most-frequently occurring cancer and the leading cause of cancer-associated deaths worldwide. Non-small cell lung cancer (NSCLC), the most common type of lung cancer is often diagnosed in middle or advanced stages and have poor prognosis. Diagnosis of disease at an early stage is a key factor for improving prognosis and reducing mortality, whereas, the currently used diagnostic tools are not sufficiently sensitive for early-stage NSCLC. The emergence of liquid biopsy has ushered in a new era of diagnosis and management of cancers, including NSCLC, since analysis of circulating tumor-derived components, such as cell-free DNA (cfDNA), circulating tumor cells (CTCs), cell-free RNAs (cfRNAs), exosomes, tumor-educated platelets (TEPs), proteins, and metabolites in blood or other biofluids can enable early cancer detection, treatment selection, therapy monitoring and prognosis assessment. There have been great advances in liquid biopsy of NSCLC in the past few years. Hence, this chapter introduces the latest advances on the clinical application of cfDNA, CTCs, cfRNAs and exosomes, with a particular focus on their application as early markers in the diagnosis, treatment and prognosis of NSCLC.

Non-Coding RNAs as Biomarkers for Embryo Quality and Pregnancy Outcomes: A Systematic Review and Meta-Analysis

Despite advances in in vitro fertilization (IVF), there is still a lack of non-invasive and reliable biomarkers for selecting embryos with the highest developmental and implantation potential. Recently, small non-coding RNAs (sncRNAs) have been identified in biological fluids, and extracellular sncRNAs are explored as diagnostic biomarkers in the prediction of IVF outcomes. To determine the predictive role of sncRNAs in embryo quality and IVF outcomes, a systematic review and meta-analysis was performed. Articles were retrieved from PubMed, EMBASE, and Web of Science from 1990 to 31 July 2022. Eighteen studies that met the selection criteria were analyzed. In total, 22 and 47 different sncRNAs were found to be dysregulated in follicular fluid (FF) and embryo spent culture medium (SCM), respectively. MiR-663b, miR-454 and miR-320a in FF and miR-20a in SCM showed consistent dysregulation in two different studies. The meta-analysis indicated the potential predictive performance of sncRNAs as non-invasive biomarkers, with a pooled area under curve (AUC) value of 0.81 (95% CI 0.78, 0.844), a sensitivity of 0.79 (95% CI 0.72, 0.85), a specificity of 0.67 (95% CI 0.52, 0.79) and a diagnostic odds ratio (DOR) of 8 (95% CI 5, 12). Significant heterogeneity was identified among studies in sensitivity (I2  =  46.11%) and specificity (I2  =  89.73%). This study demonstrates that sncRNAs may distinguish embryos with higher developmental and implantation potentials. They can be promising non-invasive biomarkers for embryo selection in ART. However, the significant heterogeneity among studies highlights the demand for prospective multicenter studies with optimized methods and adequate sample sizes in the future.

Cell-Free DNA as a New Biomarker of IVF Success, Independent of Any Infertility Factor, Including Endometriosis

Cell-free DNA fragments detected in blood and in other biological fluids are released from apoptotic/necrotic cells. In this study, we analyzed cfDNA levels in follicular fluid (FF) samples from patients with infertility. Samples were collected from 178 infertile women and cfDNA was extracted and quantified by qPCR, using ALU115 and ALU247 primers, and statistical correlations were performed. We found that cfDNA concentration was significantly higher in FF pools from women aged 35 and over than in women under 35 years of age (p = 0.017). We also found that q247 cfDNA levels were significantly higher in women with an associated female factor, such as endometriosis, PCOS and POF, compared with women with no specific cause of infertility (p = 0.033). The concentration of cfDNA did not vary significantly in each group of women with an associated female factor. The concentration of cfDNA was significantly higher in the FF of women that obtained embryos with a high fragmentation rate, compared to embryos with a low fragmentation rate (p = 0.007). Finally, we found that women who did not become pregnant during IVF treatments had higher q247 cfDNA levels (p = 0.043). The quantification of cfDNA could be an important biomarker of follicular micro-environment quality to predict embryo quality and the success of IVF, making them more specific and effective.

Low STING expression promotes endometrial stromal cell invasion and migration via the STING/IRF-3/IFN-β1 pathway in eutopic endometrium of women with endometriosis

Aims: The primary aim of the current study was to elucidate the function of the stimulator of interferon genes (STING) in the eutopic endometrium of women with endometriosis. Materials and Methods: STING expression and signaling pathways were verified by western blot analysis and immunohistochemistry after si-STING treatment. Cell proliferation and invasion and migration were assessed using 5-ethynyl-2'-deoxyuridine and transwell assays, respectively. Results: Within endometriosis tissues, STING was primarily expressed in the stroma of the eutopic endometrium and glandular epithelium of the ectopic endometrium. However, STING expression was significantly lower in the eutopic endometrium of patients with endometriosis compared to controls (p < 0.05). Additionally, cell proliferation (0.2866 ± 0.01470 vs. 0.6911 ± 0.01796, ^****p < 0.0001), invasion (130.0 ± 6.296 vs. 424.1 ± 22.31, ^****p < 0.0001), and migration (82.93 ± 6.940 vs. 82.93 ± 6.940, ^****p < 0.0001) were significantly increased in the si-STING groups. Moreover, following si-STING transfection, the expression of phosphorylated IRF-3 and TBK1 that are involved in STING/IRF3/IFNb1 signaling pathway decreased. The addition of exogenous IFN-β1 effectively increased stromal cell invasion (IFN-β1-NC vs. IFN-β1-si-STING 274.7 ± 7.767 vs. 135.7 ± 12.63, ***p < 0.0001) and migration (IFN-β1-NC and IFN-β1-si-STING 28.53 ± 3.625 vs. 28.53 ± 3.625, ***p < 0.0001) without significantly impacting cell proliferation (si-STING vs. IFN-1β-si-STING 0.6874 ± 0.02081 vs. 0.7187 ± 0.02638, p = 0.795). Conclusions: The STING signaling pathway plays an important role in endometrial stromal cell proliferation, invasion and migration associated with endometriosis.

The Role of Non-Coding RNAs in the Human Placenta

Non-coding RNAs (ncRNAs) play a central and regulatory role in almost all cells, organs, and species, which has been broadly recognized since the human ENCODE project and several other genome projects. Nevertheless, a small fraction of ncRNAs have been identified, and in the placenta they have been investigated very marginally. To date, most examples of ncRNAs which have been identified to be specific for fetal tissues, including placenta, are members of the group of microRNAs (miRNAs). Due to their quantity, it can be expected that the fairly larger group of other ncRNAs exerts far stronger effects than miRNAs. The syncytiotrophoblast of fetal origin forms the interface between fetus and mother, and releases permanently extracellular vesicles (EVs) into the maternal circulation which contain fetal proteins and RNA, including ncRNA, for communication with neighboring and distant maternal cells. Disorders of ncRNA in placental tissue, especially in trophoblast cells, and in EVs seem to be involved in pregnancy disorders, potentially as a cause or consequence. This review summarizes the current knowledge on placental ncRNA, their transport in EVs, and their involvement and pregnancy pathologies, as well as their potential for novel diagnostic tools.

Overview of miRNAs for the non-invasive diagnosis of endometriosis: evidence, challenges and strategies. A systematic review

OBJECTIVE

The aim of the study was to assess the evidence on miRNAs as biomarkers for the diagnosis of endometriosis, as well as to provide insights into the challenges and strategies associated with the use of these molecules as accessible tools in clinical practice.

METHODS

Systematic review conducted on PubMed®, Latin American and Caribbean Health Sciences Literature (LILACS), MEDLINE® and Web of Science databases using the search terms endometriosis (all fields) AND miRNA (all fields), evaluating all publication up to May 2019.

RESULTS

Most miRNAs found to be dysregulated in this study were harvested from tissue samples, which precludes their use as a non-invasive diagnostic test. However, differential expression of 62 miRNAs was reported in samples that may be used for non-invasive diagnosis of endometriosis, such as blood, serum and plasma.

CONCLUSION

Despite the identification of several candidates, studies are investigatory in nature and have been conducted with small number of samples. Also, no particular miRNA has been validated for diagnostic purposes so far. Studies based primarily on biological samples and applicable to translational research are warranted. Large databases comprising information on sample type and the use of saliva and vaginal fluid for miRNAs identification may prove essential to overcome current barriers to diagnosis of endometriosis.

The role of microRNAs in ovarian function and the transition toward novel therapeutic strategies in fertility preservation: from bench to future clinical application

BACKGROUND

New therapeutic approaches in oncology have converted cancer from a certain death sentence to a chronic disease. However, there are still challenges to be overcome regarding the off-target toxicity of many of these treatments. Oncological therapies can lead to future infertility in women. Given this negative impact on long-term quality of life, fertility preservation is highly recommended. While gamete and ovarian tissue cryopreservation are the usual methods offered, new pharmacological-based options aiming to reduce ovarian damage during oncological treatment are very attractive. In this vein, advances in the field of transcriptomics and epigenomics have brought small noncoding RNAs, called microRNAs (miRNAs), into the spotlight in oncology. MicroRNAs also play a key role in follicle development as regulators of follicular growth, atresia and steroidogenesis. They are also involved in DNA damage repair responses and they can themselves be modulated during chemotherapy. For these reasons, miRNAs may be an interesting target to develop new protective therapies during oncological treatment. This review summarizes the physiological role of miRNAs in reproduction. Considering recently developed strategies based on miRNA therapy in oncology, we highlight their potential interest as a target in fertility preservation and propose future strategies to make the transition from bench to clinic.

OBJECTIVE AND RATIONALE

How can miRNA therapeutic approaches be used to develop new adjuvant protective therapies to reduce the ovarian damage caused by cytotoxic oncological treatments?

SEARCH METHODS

A systematic search of English language literature using PubMed and Google Scholar databases was performed through to 2019 describing the role of miRNAs in the ovary and their use for diagnosis and targeted therapy in oncology. Personal data illustrate miRNA therapeutic strategies to target the gonads and reduce chemotherapy-induced follicular damage.

OUTCOMES

This review outlines the importance of miRNAs as gene regulators and emphasizes the fact that insights in oncology can inspire new adjuvant strategies in the field of onco-fertility. Recent improvements in nanotechnology offer the opportunity for drug development using next-generation miRNA-nanocarriers.

WIDER IMPLICATIONS

Although there are still some barriers regarding the immunogenicity and toxicity of these treatments and there is still room for improvement concerning the specific delivery of miRNAs into the ovaries, we believe that, in the future, miRNAs can be developed as powerful and non-invasive tools for fertility preservation.

Investigating apoptotic, inflammatory, and growth markers in poor responders undergoing natural in vitro fertilization cycles: a pilot study

This study investigates follicular fluid (FF) from patients with poor and normal ovarian response undergoing natural assisted reproductive technology cycles. We report about (1) cell-free DNA (cfDNA), which reflects apoptosis; (2) corticotropin-releasing hormone (CRH); (3) interleukin (IL)-15, which reflects inflammation; (4) granulocyte colony-stimulating factor (G-CSF); (5) vascular endothelial growth factor (VEGF); and (6) insulin-like growth factor I (IGF-I), which reflects follicular growth. Forty-four poor responders and 44 normal responders-according to the Bologna criteria-were recruited. FF samples were prepared for cfDNA quantification employing Q-PCR and for CRH, IL-15, G-CSF, VEGF, and IGF-I quantification employing ELISA. Statistically nonsignificant different levels of FF cfDNA, CRH, IL-15, VEGF, and IGF-I were observed. Interestingly, statistically significant higher G-CSF levels were observed in normal responders (302.48 ± 474.36 versus 200.10 ± 426.79 pg/mL, P = 0.003). Lower cfDNA integrity was observed in cycles resulting in clinical pregnancy for both groups (normal: 0.07 ± 0.04 versus 0.25 ± 0.17 ng/μL, P < 0.001; poor: 0.10 ± 0.06 versus 0.26 ± 0.12 ng/μL, P < 0.001). The results predominantly showcase similarities between normal and poor responders pertaining to inflammatory, apoptotic, and growth factors. This may be attributed to the employment of natural cycles in order to exclude controlled ovarian stimulation as a factor-indicating its detrimental effect. As G-CSF levels presented significantly higher in normal responders, its vital role in understanding a compromised ovarian response is highlighted.

Plasma miRNAs as biomarkers for endometriosis

STUDY QUESTION

Can plasma miRNAs be used for the non-invasive diagnosis of endometriosis in infertile women?

SUMMARY ANSWER

miRNA-based diagnostic models for endometriosis failed the test of independent validation.

WHAT IS KNOWN ALREADY

Circulating miRNAs have been described to be differentially expressed in patients with endometriosis compared with women without endometriosis, suggesting that they could be used for the non-invasive diagnosis of endometriosis. However, these studies have shown limited consistency or conflicting results, and no miRNA-based diagnostic test has been validated in an independent patient cohort.

STUDY DESIGN, SIZE, DURATION

We performed genome-wide miRNA expression profiling by small RNA sequencing to identify a set of plasma miRNAs with discriminative potential between patients with and without endometriosis. Expression of this set of miRNAs was confirmed by RT-qPCR. Diagnostic models were built using multivariate logistic regression with stepwise feature selection. In a final step, the models were tested for validation in an independent patient cohort.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Plasma of all patients was available in the biobank of the Leuven Endometriosis Centre of Excellence. Biomarker discovery and model development were performed in a discovery cohort of 120 patients (controls = 38, endometriosis = 82), and models were tested for validation in an independent cohort of 90 patients (controls = 30, endometriosis = 60). RNA was extracted with the miRNeasy Plasma Kit. Genome-wide miRNA expression analysis was done by small RNA sequencing using the NEBNext small RNA library prep kit and the NextSeq 500 System. cDNA synthesis and qPCR were performed using the Qiagen miScript technology.

MAIN RESULTS AND THE ROLE OF CHANCE

We identified a set of 42 miRNAs with discriminative power between patients with and without endometriosis based on genome-wide miRNA expression profiling. Expression of 41 miRNAs was confirmed by RT-qPCR, and 3 diagnostic models were built. Only the model for minimal-mild endometriosis (Model 2: hsa-miR-125b-5p, hsa-miR-28-5p and hsa-miR-29a-3p) had diagnostic power above chance performance in the independent validation (AUC = 60%) with an acceptable sensitivity (78%) but poor specificity (37%).

LIMITATIONS, REASONS FOR CAUTION

The diagnostic models were built and tested for validation in two patient cohorts from a single tertiary endometriosis centre. Further validation tests in large cohorts with patients from multiple endometriosis centres are needed.

WIDER IMPLICATION OF THE FINDINGS

Our study supports a possible biological link between certain miRNAs and endometriosis, but the potential of these miRNAs as clinically useful biomarkers is questionable in women with infertility. Large studies in well-described patient cohorts, with rigorous methodology for miRNA expression analysis, sufficient statistical power and an independent validation step, are necessary to answer the question of whether miRNAs can be used as diagnostics markers for endometriosis.

STUDY FUNDING/COMPETING INTEREST(S)

The project was funded by a grant from the Research Foundation - Flanders (FWO). A.V., D.F.O. and D.P. are PhD fellows from the FWO. T.D. is vice president and Head of Global Medical Affairs Fertility, Research and Development, Merck KGaA, Darmstadt, Germany. He is also a professor in Reproductive Medicine and Biology at the Department of Development and Regeneration, Group Biomedical Sciences, KU Leuven (University of Leuven), Belgium and an adjunct professor at the Department of Obstetrics and Gynecology in the University of Yale, New Haven, USA. Neither his corporate role nor his academic roles represent a conflict of interest with respect to the work done by him for this study. The other co-authors have no conflict of interest.

TRIAL REGISTRATION NUMBER

Not applicable.

MicroRNAs in endometriosis: biological function and emerging biomarker candidates†

MicroRNAs (miRNAs), a class of small noncoding RNA molecules, have been recognized as key post-transcriptional regulators associated with a multitude of human diseases. Global expression profiling studies have uncovered hundreds of miRNAs that are dysregulated in several diseases, and yielded many candidate biomarkers. This review will focus on miRNAs in endometriosis, a common chronic disease affecting nearly 10% of reproductive-aged women, which can cause pelvic pain, infertility, and a myriad of other symptoms. Endometriosis has delayed time to diagnosis when compared to other chronic diseases, as there is no current accurate, easily accessible, and noninvasive tool for diagnosis. Specific miRNAs have been identified as potential biomarkers for this disease in multiple studies. These and other miRNAs have been linked to target genes and functional pathways in disease-specific pathophysiology. Highlighting investigations into the roles of tissue and circulating miRNAs in endometriosis, published through June 2018, this review summarizes new connections between miRNA expression and the pathophysiology of endometriosis, including impacts on fertility. Future applications of miRNA biomarkers for precision medicine in diagnosing and managing endometriosis treatment are also discussed.

Is cell-free DNA in spent embryo culture medium an alternative to embryo biopsy for preimplantation genetic testing? A systematic review

Preimplantation genetic testing (PGT) is increasingly used worldwide. It currently entails the use of invasive techniques, i.e. polar body, blastomere, trophectoderm biopsy or blastocentesis, to obtain embryonic DNA, with major technical limitations and ethical issues. Evidence suggests that invasive PGT can lead to genetic misdiagnosis in the case of embryo mosaicism, and, consequently, to the selection of affected embryos for implantation or to the destruction of healthy embryos. Recently, spent culture medium (SCM) has been proposed as an alternative source of embryonic DNA. An increasing number of studies have reported the detection of cell-free DNA in SCM and highlighted the diagnostic potential of non-invasive SCM-based PGT for assessing the genetic status of preimplantation human embryos obtained by IVF. The reliability of this approach for clinical applications, however, needs to be determined. In this systematic review, published evidence on non-invasive SCM-based PGT is presented, and its current benefits and limitations compared with invasive PGT. Then, ways of optimizing and standardizing procedures for non-invasive SCM-based PGT to prevent technical biases and to improve performance in future studies are discussed. Finally, clinical perspectives of non-invasive PGT are presented and its future applications in reproductive medicine highlighted.

Cell-free mitochondrial DNA in human follicular fluid: a promising bio-marker of blastocyst developmental potential in women undergoing assisted reproductive technology

BACKGROUND

Cell-free mitochondrial DNA (cf-mtDNA) in body fluids has attracted much attention for the purpose of monitoring disease because of the clinical advantages. This study investigated whether the cf-mtDNA content in human follicular fluid samples was associated with oocyte and embryo developmental competence.

METHODS

We collected 225 individual follicular fluid samples from 92 patients undergoing conventional in vitro fertilization (n = 53) or intracytoplasmic sperm injection (n = 39). cf-mtDNA and cell-free nuclear DNA (cf-nDNA) were measured using real-time quantitative PCR for the ND1 and β-globin genes. Multivariate logistic regression and linear regression were used to analyze data.

RESULTS

The relative cf-mtDNA content (cf-ND1/cf-β-globin ratio) in follicular fluid was significantly lower in the group showing blastocyst development than in the non-blastocyst group (P = 0.030). Additionally, the relative cf-mtDNA content was significantly and positively correlated with the age of the female patient (P = 0.009), while the relative cf-mtDNA content for older women (≥38 years old) with anti-Müllerian hormone (AMH) ≤1.1 ng/ml was significantly higher than in those with AMH > 1.1 ng/ml (P <0.05). The cf-nDNA content was significantly positively correlated with the antral follicle count (P = 0.012), and significantly negatively correlated with both the number of days of stimulation and the total dose of gonadotropin administration (P = 0.039 and P = 0.015, respectively). Neither cf-mtDNA nor cf-nDNA levels in follicular fluid were associated with oocyte maturation, fertilization, or Day 3 embryo morphological scoring.

CONCLUSIONS

The relative cf-mtDNA content in human follicular fluid was negatively correlated with blastulation and positively correlated with the patient age, indicating that it is a promising bio-marker to evaluate oocyte developmental competence.

Gynecologic Cancers: Molecular Updates 2018

Ovarian carcinoma continues to be a concern for woman and maintains significant morbidity and mortality. Emerging molecular markers are providing additional opportunities for effective diagnosis and prognosis of disease. An integrated clinicopathologic and molecular classification of gynecologic malignancies has the potential to refine the clinical risk prediction of patients with cancer and to provide more tailored treatment recommendations.

Molecular Diagnostics in Esophageal and Gastric Neoplasms: 2018 Update

Esophageal cancer (EC) is rapidly increasing in incidence in the United States. Genetic changes associated with the development of EC involve the p16, p53, and APC genes. Human epidermal growth factor 2 (HER-2) overexpression is seen in gastroesophageal junction carcinoma and a subset gastric carcinoma (GC). Interestingly, up to 50% cases of GC are related to Helicobacter pylori infection and up to 16% are related to EBV infection. Microsatellite instability is observed in up to 39% of GC and cell free nucleic acid analysis provides additional opportunities for diagnosis and prognosis of disease.

Breast Carcinoma: Updates in Molecular Profiling 2018

The most significant contribution of molecular subtyping of breast carcinomas has been the identification of estrogen-positive and estrogen-negative tumor subtypes. Knowledge of genetic alterations in these tumors will help clinicians identify novel therapeutic targets. Understanding the progression pathways involved in the transition of in situ carcinoma to invasive carcinoma might lead to efficient risk stratification in these patients. The Cancer Genome Analysis Network has collected genomic and epigenomic data to provide comprehensive information regarding carcinogenesis and pathway interactions. Such information improves understanding of the disease process and also provides more accurate information toward identifying targetable mutations for treatment.

Prognostic value of various subtypes of extracellular DNA in ovarian cancer patients

Background

Patients with ovarian cancer represent a heterogeneous population with a variable prognosis and response to chemotherapy. Plasma DNA has been shown to have a prognostic value in different types of cancer including ovarian carcinoma. Whether total circulating DNA, which can be assessed much easier without knowing the tumor-specific mutations, has similar informative value is currently unknown. The aim of this study was to evaluate the prognostic value of extracellular DNA in advanced ovarian cancer.

Methods

This prospective study included 67 patients (pts) with ovarian cancer treated with 1st line paclitaxel and carboplatin (25 pts) and paclitaxel, carboplatin and bevacizumab (42 pts). Thirty-five patients had optimal surgical debulking before chemotherapy. Extracellular DNA was quantified using real time PCR before administration of chemotherapy (67 pts) and after 6 cycles of chemotherapy (44 pts).

Results

Total extracellular DNA (ecDNA), as well as extracellular DNA of nuclear (nDNA) and mitochondrial origin (mtDNA) significantly (p < 0.05) decreased after 6 cycles of chemotherapy (by 54%, 63% and 52%, respectively. Patients with stage I disease had significantly lower mtDNA compared to patients with stage II-IV (8604 vs. 16, 984 ge/mL, p = 0.03). Patients with lower baseline nDNA had superior progression-free (HR = 0.35 (0.14–0.86)) and overall survival (HR = 0.18 (0.04–0.77). The prognostic value of nDNA was confirmed independent of tumor stage and confirmed in multivariate analysis.

Conclusions

Our data suggest that ecDNA of both, nuclear and mitochondrial origin could be added to prognostic markers in ovarian cancer. Analysis of ecDNA does not require the knowledge of tumor-specific mutations in contrast to the quantification of tumor-derived ecDNA. Study of the dynamics and cell type-specific source of the ecDNA could shed light on its biology in cancer and might help to direct the treatment of ovarian cancer.

Gynecologic Health and Disease Research at the Eunice Kennedy Shriver National Institute of Child Health and Human Development: A Scientific Vision

In May 2016, the newly formed Gynecologic Health and Disease Branch in the Eunice Kennedy Shriver National Institute of Child Health and Human Development invited experts to a 2-day meeting aimed at identification of emerging opportunities in gynecologic investigation. Four primary disorders were chosen for emphasis because they represent the majority of the current Gynecologic Health and Disease Branch portfolio: uterine leiomyomas, endometriosis, pelvic floor disorders, and gynecologic pain conditions. Discussions generated a set of seven cross-cutting themes, which encompass both gaps in our current knowledge and potential directions for further research. These themes formed a continuum for understanding these disorders beginning with the need for classification systems, improved understanding of the natural history and etiology of these disorders, development of novel diagnostics, identification of opportunities for prevention, and the generation of new treatments using cutting-edge approaches. Along with these themes, three broad strategies were proposed to facilitate future research. First, investigators should improve utilization of existing research resources and focus on developing new resources to include databases, biospecimen repositories, animal models, and patient cohorts. Second, multidisciplinary scientific partnerships should be strengthened to bring new insights and approaches to gynecologic research. Third, patient and health care provider education must be promoted to ensure timely and accurate diagnosis and optimize treatment of gynecologic disorders. This article provides a summary of the workshop themes and suggestions, several of which have already been implemented through the development of program priorities and funding opportunity announcements aimed at improving women's reproductive health.

Circulating tumor cells and cell-free nucleic acids in patients with gynecological malignancies

The ability to detect cancer cells in the blood or in the bone marrow offers invaluable information which potentially impacts early diagnosis, monitoring of treatment, and prognosis. Accessing blood or other body fluids has the additional advantage of being less invasive than biopsy. Consequently, considerable effort has been invested in the last 20 years in optimizing assays which may identify malignant cells at these anatomic sites. Detection of nucleic acids has been applied as alternative approach in this context, first targeting single cancer-associated genes using PCR-based technology, and recently using assays which identify different DNA classes, as well as microRNAs and exosomes. The present review focuses on studies which applied these assays to the detection of cells or cellular components originating from gynecological cancers.

The Immunopathophysiology of Endometriosis

Endometriosis is a chronic, inflammatory, estrogen-dependent disease characterized by the growth of endometrial tissue outside of the uterine cavity. Although the etiology of endometriosis remains elusive, immunological dysfunction has been proposed as a critical facilitator of ectopic lesion growth following retrograde menstruation of endometrial debris. However, it is not clear whether this immune dysfunction is a cause or consequence of endometriosis. Thus, here we provide in-depth insights into our current understanding of the immunopathophysiology of endometriosis and highlight challenges and opportunities for future research. With the explosion of successful immune-based therapies targeting various chronic inflammatory conditions, it is crucial to determine whether immune dysfunction can be therapeutically targeted in endometriosis.

Pushing the limits of detection: investigation of cell-free DNA for aneuploidy screening in embryos

OBJECTIVE

To determine the accuracy of cell-free DNA (cfDNA) in spent embryo medium (SEM) for ploidy and sex detection at the cleavage and blastocyst stages. To determine if assisted hatching (AH) and morphologic grade influence cfDNA concentration and accuracy.

DESIGN

Prospective cohort.

SETTING

Academic fertility center.

PATIENT(S)

Nine patients undergoing IVF; 41 donated two-pronuclei embryos and 20 embryos from patients undergoing preimplantation genetic testing for aneuploidy (PGT-A).

INTERVENTIONS(S)

In a donated embryo arm, SEM was collected on days 3 and 5, with one-half of the embryos undergoing AH before and one-half after. In a clinical arm, SEM was collected on day 5 before trophectoderm (TE) biopsy. Samples underwent PGT-A with the use of next-generation sequencing. cfDNA results were compared with corresponding whole embryos and TE biopsies.

MAIN OUTCOME MEASURE(S)

Concordance rates, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for ploidy and sex detection with the use of cfDNA.

RESULT(S)

Of 141 samples, cfDNA was amplified in 39% and 80.4% of days 3 and 5 SEM, respectively. Concordances for ploidy and sex, respectively, were 56.3% and 81.3% between day 3 cfDNA and whole embryos, and 65% and 70% between day 5 cfDNA and TE biopsies. Day 5 cfDNA sensitivity and specificity for aneuploidy were 0.8 and 0.61, respectively. PPV and NPV were 0.47 and 0.88, respectively. Timing of AH and morphology did not influence cfDNA concentration or accuracy.

CONCLUSION(S)

cfDNA is detectable on days 3 and 5, but more accurate on day 5. Although our data suggest moderate concordance rates, PGT-A with the use of cfDNA must be further optimized before clinical implementation.

Relationship between blastocoel cell-free DNA and day-5 blastocyst morphology

PURPOSE

Cell-free DNA (cfDNA) which is present in the blastocoel cavity of embryos is believed to result from physiological apoptosis during development. This study assessed cfDNA content and caspase-3 protease activity in day-5 IVF blastocysts to determine if there was a correlation with embryo morphology.

METHODS

Day-5 IVF blastocysts were scored according to the Gardner and Schoolcraft system (modified to generate a numerical value) and cfDNA was collected following laser-induced blastocoel collapsing prior to cryopreservation in 25 μL of media. cfDNA was quantified via fluorospectrometry and apoptotic activity was assessed via a caspase-3 protease assay using a fluorescent peptide substrate. Data were compared by linear regression.

RESULTS

A total of 32 embryos were evaluated. There was a significant (p < 0.01) and positive correlation (cfDNA = 104.753 + (11.281 × score); R² = 0.200) between embryo score and cfDNA content. A significant (p < 0.05) and positive correlation (cfDNA = 115.9 + (0.05 × caspase-3); R²= 0.128) was observed between caspase-3 activity and cfDNA levels. There was no significant relationship between caspase-3 activity and embryo morphology score.

CONCLUSIONS

This study provides further evidence that cfDNA is present in blastocoel fluid, can be quantified, and positively correlates with embryonic morphology. There is also evidence that at least a portion of the cfDNA present is from intracellular contents of embryonic cells that underwent apoptosis. Additional studies are warranted to determine other physiological sources of the cfDNA in blastocyst fluid and to determine the relationship with cfDNA content, embryo morphology, and chromosomal ploidy status plus implantation potential.

Novel approaches to early detection of endometrial cancer

PURPOSE OF REVIEW

Detection of endometrial cancer at an early stage leads to better oncologic outcomes. To date, a screening test for endometrial cancer does not exist.

RECENT FINDINGS

Evolving knowledge of molecular changes involved in endometrial cancer carcinogenesis paired with sensitive and high-throughput technological advancements are a promising combination that can be leveraged to detect tumor DNA and proteins. These molecular biomarkers can be identified in biospecimens collected via minimally invasive and noninvasive approaches. Exploiting lower genital tract secretions as a biospecimen also allows for patient self-sampling.

SUMMARY

Successful development of a screening test for endometrial cancer using self-collected lower genital tract biospecimens has the potential to increase accessibility to care and improve patient compliance.

No increase in free fetal DNA level in ectopic pregnancy: A preliminary study

Objective:

The aim of this study was to diagnose ectopic pregnancy in the early period by measuring cell-free fetal DNA (cffDNA) levels in maternal blood using spectrophotometry.

Materials and Methods:

Thirty patients with ectopic pregnancy and 30 patients with first trimester intrauterine pregnancy were enrolled in this prospective controlled study. cffDNA levels in maternal serum were measured using spectrophotometry.

Results:

There were no differences between the two groups in terms of cffDNA absorbance levels.

Conclusion:

Spectrophotometry is not suitable for measuring cffDNA levels to diagnose ectopic pregnancies in the early period. Practical and cost-effective methods should be found or larger patient series should be investigated.

Polymer-based precipitation preserves biological activities of extracellular vesicles from an endometrial cell line

Extracellular vesicles (EVs) are membrane-bound vesicles released by cells and act as media for transfer of proteins, small RNAs and mRNAs to distant sites. They can be isolated by different methods. However, the biological activities of the purified EVs have seldom been studied. In this study, we compared the use of ultracentrifugation (UC), ultra-filtration (UF), polymer-based precipitation (PBP), and PBP with size-based purification (PBP+SP) for isolation of EVs from human endometrial cells and mouse uterine luminal fluid (ULF). Electron microscopy revealed that the diameters of the isolated EVs were similar among the tested methods. UF recovered the highest number of EVs followed by PBP, while UC and PBP+SP were significantly less efficient (P<0.05). Based on the number of EVs-to-protein ratios, PBP had the least protein contamination, significantly better than the other methods (P<0.05). All the isolated EVs expressed exosome-enriched proteins CD63, TSG101 and HSP70. Incubation of the trophoblast JEG-3 cells with an equal amount of the fluorescence-labelled EVs isolated by the studied methods showed that many of the PBP-EVs treated cells were fluorescence positive but only a few cells were labelled in the UC- and UF-EVs treated groups. Moreover, the PBP-EVs could transfer significantly more miRNA to the recipient cells than the other 3 methods (P<0.05). The PBP method could isolate EVs from mouse ULF; the diameter of the isolated EVs was 62±19 nm and expressed CD63, TSG101 and HSP70 proteins. In conclusion, PBP could best preserve the activities of the isolated EVs among the 4 methods studied and was able to isolate EVs from a small volume of sample. The simple setup and low equipment demands makes PBP the most suitable method for rapid EV assessment and isolation of EVs in clinical and basic research settings.

Cell-free and intracellular nucleic acids: new non-invasive biomarkers to explore male infertility

Male infertility is a devastating problem that affects many couples worldwide. However, the molecular mechanisms and causes of idiopathic male infertility remain unclear. Circulating cell-free nucleic acids have an important role in human physiology and emerging evidence suggests that they play a role in male infertility. This review summarizes recent results on cell-free and intracellular nucleic acids in male infertility and discusses their potential use as biomarkers of male infertility in the clinical practice.

MicroRNAs: New Insight in Modulating Follicular Atresia: A Review

Our understanding of the post-transcriptional mechanisms involved in follicular atresia is limited; however, an important development has been made in understanding the biological regulatory networks responsible for mediating follicular atresia. MicroRNAs have come to be seen as a key regulatory actor in determining cell fate in a wide range of tissues in normal and pathological processes. Profiling studies of miRNAs during follicular atresia and development have identified several putative miRNAs enriched in apoptosis signaling pathways. Subsequent in vitro and/or in vivo studies of granulosa cells have elucidated the functional role of some miRNAs along with their molecular pathways. In particular, the regulatory roles of some miRNAs have been consistently observed during studies of follicular cellular apoptosis. Continued work should gradually lead to better understanding of the role of miRNAs in this field. Ultimately, we expect this understanding will have substantial benefits for fertility management at both the in vivo or/and in vitro levels. The stable nature of miRNA holds remarkable promise in clinical use as a diagnostic tool and in reproductive medicine to solve the ever-increasing fertility problem. In this review, we summarize current knowledge of the involvement of miRNAs in follicular atresia, discuss the challenges for further work and pinpoint areas for future research.

Molecular Characterization of Epithelial Ovarian Cancer: Implications for Diagnosis and Treatment

Epithelial ovarian cancer is a highly heterogeneous disease characterized by multiple histological subtypes. Molecular diversity has been shown to occur within specific histological subtypes of epithelial ovarian cancer, between different tumors of an individual patient, as well as within individual tumors. Recent advances in the molecular characterization of epithelial ovarian cancer tumors have provided the basis for a simplified classification scheme in which these cancers are classified as either type I or type II tumors, and these two categories have implications regarding disease pathogenesis and prognosis. Molecular analyses, primarily based on next-generation sequencing, otherwise known as high-throughput sequencing, are allowing for further refinement of ovarian cancer classification, facilitating the elucidation of the site(s) of precursor lesions of high-grade serous ovarian cancer, and providing insight into the processes of clonal selection and evolution that may be associated with development of chemoresistance. Potential therapeutic targets have been identified from recent molecular profiling studies of these tumors, and the effectiveness and safety of a number of specific targeted therapies have been evaluated or are currently being studied for the treatment of women with this disease.

Circulating Levels of Pregnancy-Associated, Placenta-Specific microRNAs in Pregnant Women With Placental Abruption

The aim of this study was to clarify the association between circulating pregnancy-associated, placenta-specific microRNAs (miRNAs) in maternal plasma and placental abruption. All samples were obtained after receiving written informed consent, and the study protocol was approved by the institutional review board. Maternal blood samples (7 mL) were obtained at 25 to 40 weeks of gestation from 15 cases of placental abruption (placental abruption group) and from 24 cases of uncomplicated pregnancies (uncomplicated pregnancy group). The plasma concentrations of pregnancy-associated, placenta-specific miRNAs (miR-515-3p, -517a, -517c, and -518b) were measured by quantitative real-time reverse transcription-polymerase chain reaction. There were no significant differences in clinical characteristics between the 2 groups. The median concentration of plasma cell-free miR-517c in the placental abruption group was 21 672.2 copies/mL, whereas that in the uncomplicated pregnancy group was 13 452.0 copies/mL (Mann-Whitney U test, P = .047). Receiver operating characteristic curve analysis revealed that plasma cell-free miR-517c levels discriminated placental abruption from uncomplicated pregnancy with an area under the curve of 0.692. When a cutoff negative/positive value of 15 669.6 copies/mL was selected, the sensitivity and specificity were 73.3% and 62.5%, respectively. In addition, the positive and negative predictive values were 55.0% and 78.9%, respectively. Plasma cell-free miR-517a and miR-517c levels in the large abruption (degree of abruption ≥50% of placenta) group were significantly higher than in the small abruption (<50%) group ( P = .03 for both miRNAs). In conclusion, the circulating level of cell-free miR-517c in maternal plasma was increased as a consequence of placental abruption and may be a potential biomedical marker for placental abruption.

Circulating microRNAs in follicular fluid, powerful tools to explore in vitro fertilization process

Circulating or “extracellular” microRNAs (miRNAs) detected in biological fluids, could be used as potential diagnostic and prognostic biomarkers of several disease, such as cancer, gynecological and pregnancy disorders. However, their contributions in female infertility and in vitro fertilization (IVF) remain unknown. This study investigated the expression profiles of five circulating miRNAs (let-7b, miR-29a, miR-30a, miR-140 and miR-320a) in human follicular fluid from 91 women with normal ovarian reserve and 30 with polycystic ovary syndrome (PCOS) and their ability to predict IVF outcomes. The combination of FF miR-30a, miR-140 and let-7b expression levels discriminated between PCOS and normal ovarian reserve with a specificity of 83.8% and a sensitivity of 70% (area under the ROC curve, AUC = 0.83 [0.73–0.92]; p < 0.0001). FF samples related to low number of mature oocytes (≤2) contained significant less miR-320a levels than those related to a number of mature oocytes >2 (p = 0.04). Moreover, FF let-7b predicted the development of expanded blastocysts with 70% sensitivity and 64.3% specificity (AUC = 0.67 [0.54–0.79]; p = 0.02) and FF miR-29a potential to predict clinical pregnancy outcome reached 0.68 [0.55–0.79] with a sensitivity of 83.3% and a specificity of 53.5% (p = 0.01). Therefore, these miRNAs could provide new helpful biomarkers to facilitate personalized medical care during IVF.

Extracellular vesicles: roles in gamete maturation, fertilization and embryo implantation

BACKGROUND

Extracellular vesicles (EVs) are membrane-bound vesicles, found in biofluids, that carry and transfer regulatory molecules, such as microRNAs (miRNAs) and proteins, and may mediate intercellular communication between cells and tissues. EVs have been isolated from a wide variety of biofluids, including plasma, urine, and, relevant to this review, seminal, follicular and uterine luminal fluid. We conducted a systematic search of the literature to review and present the currently available evidence on the possible roles of EVs in follicular growth, resumption of oocyte development and maturation (meiosis), sperm maturation, fertilization and embryo implantation.

METHODS

MEDLINE, Embase and Web of Science databases were searched using keywords pertaining to EVs, including 'extracellular vesicles', 'microvesicles', 'microparticles' and 'exosomes', combined with a range of terms associated with the period of development between fertilization and implantation, including 'oocyte', 'sperm', 'semen', 'fertilization', 'implantation', 'embryo', 'follicular fluid', 'epididymal fluid' and 'seminal fluid'. Relevant research articles published in English (both animal and human studies) were reviewed with no restrictions on publication date (i.e. from earliest database dates to July 2015). References from these articles were used to obtain additional articles.

RESULTS

A total of 1556 records were retrieved from the three databases. After removing duplicates and irrelevant titles, we reviewed the abstracts of 201 articles, which included 92 relevant articles. Both animal and human studies unequivocally identified various types of EVs in seminal, follicular and ULFs. Several studies provided evidence for the roles of EVs in these biofluids. In men, EVs in seminal fluid were linked with post-testicular sperm maturation, including sperm motility acquisition and reduction of oxidative stress. In women, EVs in follicular fluid were shown to contain miRNAs with potential roles in follicular growth, resumption of oocyte meiosis, steroidogenesis and prevention of polyspermy after fertilization. EVs were also detected in the media of cultured embryos, suggesting that EVs released from embryos and the uterus may mediate embryo-endometrium cross-talk during implantation. It is important to note that many of the biologically plausible functions of EVs in reproduction discussed in the current literature have not yet been substantiated by conclusive experimental evidence.

CONCLUSIONS

A detailed understanding of the contributions of EVs in the series of events from gametogenesis to fertilization and then on to implantation, in both normal and pathological cases, may enable the development of valuable tools to advance reproductive health. Because of the early stage of the field, it is unsurprising that the current literature includes not only growing experimental evidence, but also as-yet unproven hypotheses pertaining to the roles of EVs in key reproductive processes. In this review, we present a comprehensive survey of the rapidly expanding literature on this subject, highlighting both relevant findings and gaps in knowledge.

Cell-free DNA and telomere length among women undergoing in vitro fertilization treatment

PURPOSE

The current research is aimed at finding potential non-invasive bio-markers that will help us learn more about the mechanisms at play in failed assisted reproduction treatment. This exploratory pilot study examined the relationship between cell-free DNA (CFD) in plasma and telomere length in lymphocytes among women undergoing in vitro fertilization (IVF) and compared telomere length and CFD levels to a healthy control group.

METHODS

Blood of 20 women undergoing IVF was collected at three time points during the IVF cycle. We assessed the relationship between CFD and telomere length as well as controlling for morning cortisol levels. We also collected blood of 10 healthy controls at two time points (luteal and follicular phases of the menstrual cycle) and compared mean telomere length, CFD, and cortisol levels between the IVF patients and healthy controls.

RESULTS

The results revealed an inverse relationship between CFD levels and telomere lengths at several time points that remained significant even after controlling for cortisol levels. Women undergoing IVF had statistically significant higher levels of CFD and shorter telomeres compared to healthy controls.

CONCLUSIONS

The relationship between telomere length and CFD should be further explored in larger studies in order to uncover potential mechanisms that cause both shortened telomere length and elevated CFD in women undergoing IVF.

Altered expression of microRNA-451 in eutopic endometrium of baboons (Papio anubis) with endometriosis

STUDY QUESTION

Are microRNAs (miRs) altered in the eutopic endometrium (EuE) of baboons following the induction of endometriosis?

SUMMARY ANSWER

Induction of endometriosis causes significant changes in the expression of eight miRs, including miR-451, in the baboon endometrium as early as 3 months following induction of the disease.

WHAT IS KNOWN ALREADY

Endometriosis is one of the most common gynecological disorders and causes chronic pelvic pain and infertility in women of reproductive age. Altered expression of miRs has been reported in women and has been suggested to play an important role in the pathophysiology of several gynecological disorders including endometriosis.

STUDY DESIGN, SIZE, DURATION

EuE was obtained from the same group of baboons before and 3 months after the induction of endometriosis. The altered expression of miR-451 was validated in the eutopic and ectopic endometrium of additional baboons between 3 and 15 months following disease induction. Timed endometrial biopsies from women with and without endometriosis were also used to validate the expression of miR-451.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Total RNA was extracted from EuE samples before and after the induction of endometriosis, and miRNA expression was analyzed using a 8 × 15 K miR microarray. Microarray signal data were preprocessed by AgiMiRna software, and an empirical Bayes model was used to estimate the changes. The present study focused on quantitative RT-PCR validation of the microarray data, specifically on miR-451 and its target genes in both baboons (n = 3) and women [control (n = 7) and endometriosis (n = 19)]. Descriptive and correlative analysis of miR-451 and target gene expression was conducted using in situ hybridization and immunohistochemistry, while functional analysis utilized an in vitro 3' untranslated region (UTR) luciferase assay and overexpression of miR-451 in human endometrial and endometriotic cell lines.

MAIN RESULTS AND THE ROLE OF CHANCE

Induction of endometriosis results in the altered expression of miR-451, -141, -29c, -21, -424, -19b, -200a and -181a in the baboon endometrium. In the baboon, induction of endometriosis significantly decreased the expression of miR-451 at 3 months (P < 0.001), which was also associated with increased expression of its target gene YWHAZ (14.3.3ζ). A similar significant (P < 0.0001) decrease in miR-451 expression was observed in women with endometriosis. The 3' UTR luciferase assay confirmed the regulation of YWHAZ expression by miR-451. Furthermore, overexpression of miR-451 in 12Z cells (immortalized human endometriotic epithelial cell line) led to the decreased expression of its target YWHAZ and this was correlated with decreased cell proliferation.

LIMITATIONS, REASONS FOR CAUTION

The study focused only on miR-451 and one of its targets, namely YWHAZ. A single miR could target number of genes and a single gene could also be regulated by number of miRs; hence, it is possible that other miRs and their regulated genes may contribute to the pathophysiology of endometriosis.

WIDER IMPLICATIONS OF THE FINDINGS

Our data suggest that the presence of ectopic lesions in baboon causes changes in EuE miR expression as early as 3 months postinduction of the disease, and some of these changes may persist throughout the course of the disease. We propose that the marked down-regulation of miR-451 in both baboons and women with endometriosis increases the expression of multiple target genes. Increased expression of one of the target genes, YWHAZ, increases proliferation, likely contributing to the pathophysiology of the disease.

[Circulating nucleic acids and infertility]

Circulating nucleic acids (cell-free DNA and microRNAs) have for particularity to be easily detectable in the biological fluids of the body. Therefore, they constitute biomarkers of interest in female and male infertility care. Indeed, in female, they can be used to detect ovarian reserve disorders (polycystic ovary syndrome and low functional ovarian reserve) as well as to assess follicular microenvironment quality. Moreover, in men, their expression levels can vary in case of spermatogenesis abnormalities. Finally, circulating nucleic acids have also the ability to predict successfully the quality of in vitro embryo development. Their multiple contributions during assisted reproductive technology (ART) make of them biomarkers of interest, for the development of new diagnostic and/or prognostic tests, applied to our specialty. Circulating nucleic acids would so offer the possibility of personalized medical care for infertile couples in ART.

Cell-free DNA in Human Follicular Microenvironment: New Prognostic Biomarker to Predict in vitro Fertilization Outcomes

Cell-free DNA (cfDNA) fragments, detected in blood and in other biological fluids, are released from apoptotic and/or necrotic cells. CfDNA is currently used as biomarker for the detection of many diseases such as some cancers and gynecological and obstetrics disorders. In this study, we investigated if cfDNA levels in follicular fluid (FF) samples from in vitro fertilization (IVF) patients, could be related to their ovarian reserve status, controlled ovarian stimulation (COS) protocols and IVF outcomes. Therefore, 117 FF samples were collected from women (n = 117) undergoing IVF/Intra-cytoplasmic sperm injection (ICSI) procedure and cfDNA concentration was quantified by ALU-quantitative PCR. We found that cfDNA level was significantly higher in FF samples from patients with ovarian reserve disorders (low functional ovarian reserve or polycystic ovary syndrome) than from patients with normal ovarian reserve (2.7 ± 2.7 ng/μl versus 1.7 ± 2.3 ng/μl, respectively, p = 0.03). Likewise, FF cfDNA levels were significant more elevated in women who received long ovarian stimulation (> 10 days) or high total dose of gonadotropins (≥ 3000 IU/l) than in women who received short stimulation duration (7–10 days) or total dose of gonadotropins < 3000 IU/l (2.4 ± 2.8 ng/μl versus 1.5 ± 1.9 ng/μl, p = 0.008; 2.2 ± 2.3 ng/μl versus 1.5 ± 2.1 ng/μl, p = 0.01, respectively). Finally, FF cfDNA level was an independent and significant predictive factor for pregnancy outcome (adjusted odds ratio = 0.69 [0.5; 0.96], p = 0.03). In multivariate analysis, the Receiving Operator Curve (ROC) analysis showed that the performance of FF cfDNA in predicting clinical pregnancy reached 0.73 [0.66–0.87] with 88% specificity and 60% sensitivity. CfDNA might constitute a promising biomarker of follicular micro-environment quality which could be used to predict IVF prognosis and to enhance female infertility management.

Non-invasive pre-implantation genetic diagnosis of X-linked disorders

Pre-implantation genetic diagnosis (PGD) is a powerful clinical tool to identify embryos with or at risk of specific genetic diseases before implantation in utero after in vitro fertilization (IVF). PGD is performed on embryo biopsies that are obtained by aspiration of one or two cells from pre-implantation embryos at day 3 or day 5/6 of culture. However this is a traumatic method that cannot be avoided because non-invasive procedures to assess the genetic status of pre-implantation embryos are not available yet. We hypothesize that cell-free nucleic acids, which are released by embryos in the culture medium during the IVF procedure, could be used for genetic screening. To test our hypothesis we will focus first on X-linked disorders because these single-gene diseases due to the presence of defective genes on the X chromosome are dominant in males. Therefore the objective here is to discriminate between female (XX) and male (XY) embryos by detecting Y chromosome-specific sequences in cell-free nucleic acids. Using culture medium from embryos we are able to discriminate between male and female embryos. This opens new avenues for the development of a non-invasive PGD method.