Non‑coding RNAs and ovarian diseases (Review)

Circulating microRNAs for Early Diagnosis of Ovarian Cancer: A Systematic Review and Meta-Analysis

In this study, we conducted a systematic review and meta-analysis to summarize and evaluate the global research potential of different circulating miRNAs as an early diagnostic biomarker for OC. A systematic literature search for relevant studies was conducted in June 2020 and followed up in November 2021. The search was conducted in English databases (PubMed, ScienceDirect). The primary search resulted in a total of 1887 articles, which were screened according to the prior established inclusion and exclusion criteria. We identified 44 relevant studies, of which 22 were eligible for the quantitative meta-analysis. Statistical analysis was performed using the Meta-package in Rstudio. Standardized mean differences (SMD) of relative levels between control subjects and OC patients were used to evaluate the differential expression. All studies were quality evaluated using a Newcastle-Ottawa Scale. Based on the meta-analysis, nine miRNAs were identified as dysregulated in OC patients compared to controls. Nine were upregulated in OC patients compared to controls (miR-21, -125, -141, -145, -205, -328, -200a, -200b, -200c). Furthermore, miR-26, -93, -106 and -200a were analyzed, but did not present an overall significant difference between OC patients and controls. These observations should be considered when performing future studies of circulating miRNAs in relation to OC: sufficient size of clinical cohorts, development of consensus guidelines for circulating miRNA measurements, and coverage of previously reported miRNAs.

Application of Single-Cell RNA Sequencing in Ovarian Development

The ovary is a female reproductive organ that plays a key role in fertility and the maintenance of endocrine homeostasis, which is of great importance to women's health. It is characterized by a high heterogeneity, with different cellular subpopulations primarily containing oocytes, granulosa cells, stromal cells, endothelial cells, vascular smooth muscle cells, and diverse immune cell types. Each has unique and important functions. From the fetal period to old age, the ovary experiences continuous structural and functional changes, with the gene expression of each cell type undergoing dramatic changes. In addition, ovarian development strongly relies on the communication between germ and somatic cells. Compared to traditional bulk RNA sequencing techniques, the single-cell RNA sequencing (scRNA-seq) approach has substantial advantages in analyzing individual cells within an ever-changing and complicated tissue, classifying them into cell types, characterizing single cells, delineating the cellular developmental trajectory, and studying cell-to-cell interactions. In this review, we present single-cell transcriptome mapping of the ovary, summarize the characteristics of the important constituent cells of the ovary and the critical cellular developmental processes, and describe key signaling pathways for cell-to-cell communication in the ovary, as revealed by scRNA-seq. This review will undoubtedly improve our understanding of the characteristics of ovarian cells and development, thus enabling the identification of novel therapeutic targets for ovarian-related diseases.

Identification of potential key circular RNAs related to cognitive impairment after chronic constriction injury of the sciatic nerve

Chronic neuropathic pain is commonly accompanied by cognitive impairment. However, the underlying mechanism in the occurrence of cognitive deficits under constant nociceptive irritation remains elusive. Herein, we established a chronic neuropathic pain model by chronic constriction injury (CCI) of the unilateral sciatic nerve in rats. Behavioral tests indicated that CCI rats with long-term nociceptive threshold decline developed significant dysfunction of working memory and recognitive memory starting at 14 days and lasting for at least 21 days. Afterward, circRNA expression profiles in the hippocampus of CCI and sham rats were analyzed via high-throughput sequencing to explore the potential key factors associated with cognitive impairment induced by ongoing nociception, which showed 76 differentially expressed circRNAs, 39 upregulated and 37 downregulated, in the CCI group. These differentially expressed circRNA host genes were validated to be primarily associated with inflammation and apoptotic signaling pathways according to GO/KEGG analysis and the circRNA-miRNA-mRNA network, which was also confirmed through the analysis of neuroinflammation and neuronal apoptosis. Consequently, we assumed that enhanced neuroinflammation and neuronal apoptosis might act as potential regulators of cognitive impairment induced by chronic neuropathic pain. The identification of the regulatory mechanism would provide promising clinical biomarkers or therapeutic targets in the diagnostic prediction and intervention treatment of memory deficits under neuropathic pain conditions.

Non-coding RNAs and their cross-talks impacting reproductive health of women

Non-coding RNAs (ncRNAs) work as crucial posttranscriptional modulators of gene expression regulating a wide array of biological processes that impact normal physiology, including reproductive health. The health of women, especially reproductive health, is now a prime focus of society that ensures the females' overall physical, social, and mental well-being. Furthermore, there has been a growing cognizance of ncRNAs' possible applications in diagnostics and therapeutics of dreaded diseases. Hence, understanding the functions and mode of actions of ncRNAs in the context of women's health will allow us to develop effective prognostic and therapeutic strategies that will enhance the quality of life of women. Herein, we summarize recent progress on ncRNAs, such as microRNAs (miRNAs) and long ncRNAs (lncRNAs), and their implications in reproductive health by tying the knot with lifestyle factors that affect fertility complications, pregnancy outcomes, and so forth. We also discourse the interplay among the RNA species, especially miRNAs, lncRNAs, and protein-coding RNAs, through the competing endogenous RNA regulations in diseases of women associated with maternal and fetal health. This review provides new perspectives correlating ncRNAs, lifestyle, and reproductive health of women, which will attract future studies to improve women's lives. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

Impact of Endocrine Disruptors upon Non-Genetic Inheritance

Similar to environmental factors, EDCs (endocrine-disrupting chemicals) can influence gene expression without modifying the DNA sequence. It is commonly accepted that the transgenerational inheritance of parentally acquired traits is conveyed by epigenetic alterations also known as "epimutations". DNA methylation, acetylation, histone modification, RNA-mediated effects and extracellular vesicle effects are the mechanisms that have been described so far to be responsible for these epimutations. They may lead to the transgenerational inheritance of diverse phenotypes in the progeny when they occur in the germ cells of an affected individual. While EDC-induced health effects have dramatically increased over the past decade, limited effects on sperm epigenetics have been described. However, there has been a gain of interest in this issue in recent years. The gametes (sperm and oocyte) represent targets for EDCs and thus a route for environmentally induced changes over several generations. This review aims at providing an overview of the epigenetic mechanisms that might be implicated in this transgenerational inheritance.

Long non-coding RNA placenta‑specific protein 2 regulates micorRNA-19a/tumor necrosis factor α to participate in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a type of hormonal disorder that affects about 5-20% of females at their reproductive age worldwide. MicorRNA-19a (miR-19a) is a well-characterized miRNA in cancer biology and its function is mainly mediated by targeting tumor necrosis factor α (TNF-α), which plays critical roles in PCOS. Our preliminary analysis predicted the potential interaction between miR-19a and long non-coding RNA (lncRNA) placenta‑specific protein 2 (PLAC2). Therefore, this study aimed to explore the role of PLAC2 in PCOS. Ovarian tissues were collected from 62 PCOS patients and 62 healthy females. Granulosa-like tumor cells (KGN) was prepared, and transient transfections was conducted. Dual-luciferase activity assay was used to investigate the interaction between PLAC2 and miR-19a. qPCR assays were performed for the expression analysis of miR-19a/TNF-α. In addition, Western blot analysis and cell apoptosis assay were conducted. The results showed that PLAC2 was upregulated in PCOS. PLAC2 and miR-19a showed a direct interaction, while overexpression of PLAC2 and miR-19a did not affect the expression of each other in KGN cells. Instead, overexpression of PLAC2 led to upregulated TNF-α, which is a target of miR-19a. Cell apoptosis analysis showed that PLAC2 and TNF-α promoted the apoptosis of KGN cells. Overexpression of miR-19a played an opposite role. In addition, the overexpression of PLAC2 reduced the effects of overexpression of miR-19a. Therefore, PLAC2 may regulate miR-19a/TNF-α to participate in PCOS.

New biomarkers in peripheral blood of patients with ovarian cancer: high expression levels of miR-16-5p, miR-17-5p, and miR-638

OBJECTIVES

Ovarian cancer is one of the most fatal gynecologic malignities. miR-16-5p, miR-17-5p, and miR-638 genes were found to have been associated with ovarian cancer in accordance with the data obtained from the previous microarray research performed by Tuncer et al. (J Ovarian Res 13(1):99, 2020). The expression levels of these miRNAs in the peripheral blood samples of 142 ovarian cancer patients, and 97 healthy controls were investigated for performing the validation, and to identify whether these genes were the possible biomarkers to be used in the early diagnosis of high-risk ovarian cancer patients, and in the prognosis of patients.

METHODS

The miRNA expression analysis was performed using the miRNA-specific cDNA synthesis, and real-time PCR methods following the RNA isolation from the peripheral blood lymphocytes.

RESULTS

miR-16-5p, miR-17-5p, and miR-638 miRNA gene expression levels were found to have twofold higher expression levels in patient groups compared with the gene expression levels in healthy controls, and were statistically significant (p < 0.05). In addition, the comparison of the miRNA expression levels with the clinical data of patients showed that there was a significant difference with smoking history and the increased expression level of miR-17-5 (p: 0.007). There was a significant difference between the increased expression level of miR-638 with the locally advanced stage, and abdominal/pelvic metastatic patients (p: 0.03).

CONCLUSIONS

The obtained data suggest that miR-16-5p, miR-17-5p, and miR-638 molecules might be the noninvasive biomarkers in identifying the ovarian cancer. However, the investigation and monitoring of the changeability of these biomarkers in benign ovarian diseases, and during the treatment must be performed in future studies for identifying the accurate diagnostic, and prognostic features of miRNAs.

An association study of polymorphisms in the H19 imprinted gene in an Iranian population with the risk of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrinopathies that causes problems in female fertility at the reproductive age. PCOS is a multifactorial disease, with genetic factors playing a crucial role in its development. H19 is a long non-coding RNA (lncRNA) expressed from the maternal chromosome, which is correlated with PCOS. In this study, 115 women suffering from PCOS and 130 healthy women with regular menstrual cycles were recruited as case and control groups, respectively. After the extraction of genomic DNA, the restriction fragment length polymorphism polymerase chain reaction was employed for genotyping of rs2067051G>A and rs3741219T>C. Statistical analysis was done using SPSS package V.22 for Windows. In silico analysis was recruited to determine the effects of SNPs on the secondary structure of gene transcript as well as miRNA binding sites. The obtained data showed that the A allele of rs2067051G>A was associated with the high risk of PCOS (OR = 2.00, 95%CI = 1.38-2.91, P = 0.00). AG and AA genotypes led to a 3.64- and (about) a five-fold increase in the risk of PCOS, respectively (95%CI = 2.02-6.54, P = 0.00, and 95%CI = 1.51-16.52, P = 0.00, respectively). These variants caused a significant increase in the risk of this disorder in all genotype models except in the recessive model. However, no association was found between rs3741219T>C and the increased risk of PCOS, either in the allele or in the genotype models. According to the findings, rs2067051G>A is associated with an increased risk of PCOS in the Iranian population.

Circulating microRNAs as novel potential diagnostic biomarkers for ovarian cancer: a systematic review and updated meta-analysis

OBJECT

Ovarian cancer is the primary cause of cancer-associated deaths among gynaecological malignancies. Increasing evidence suggests that microRNAs may be potential biomarkers for the diagnosis and prognosis of cancer. In this study, we conducted a systematic review and meta-analysis to summarize the global research and to evaluate the overall diagnostic accuracy of miRNAs in detecting ovarian cancer.

METHODS

A systematic literature search was conducted for relevant studies through July 20, 2017, in English databases (CENTRAL, MEDLINE, and EMBASE), the Grey reference database and Chinese databases. Statistical analysis was conducted using OpenMetaAnalyst, STATA 14.0 and RevMan 5.3. Pooled sensitivity, specificity, and other parameters were used to assess the overall miRNA assay performance using a bivariate random-effects model (BRM). Meta-regression and subgroup analyses were performed to dissect the heterogeneity. Sensitivity analysis was performed to assess the robustness of our analysis, and the publication bias of the selected studies was assessed using Deeks' funnel plot asymmetry test.

RESULTS

Thirteen articles described 33 studies, including 1081 patients with ovarian cancer and 518 controls. The pooled results were as follows: sensitivity, 0.89 (95% CI: 0.84-0.93); specificity, 0.64 (95% CI: 0.56-0.72); positive likelihood ratio, 2.18 (95% CI: 1.89-2.51); negative likelihood ratio, 0.15 (95% CI: 0.11-0.22); and diagnostic odds ratio (DOR), 13.21 (95% CI: 9.00-19.38). We conducted subgroup analyses based on ethnicity, research design, and miRNA profiling and found that multiple miRNA panels were more accurate in detecting ovarian cancer, with a combined DOR of 30.06 (95% CI: 8.58-105.37).

CONCLUSION

Per the meta-analysis, circulating miRNAs may be novel and non-invasive biomarkers for detecting ovarian cancer, particularly multiple miRNA panels, which have potential diagnostic value as screening tools in clinical practice.

Circulating microRNAs as novel potential diagnostic biomarkers for ovarian cancer: a systematic review and updated meta-analysis

OBJECT

Ovarian cancer is the primary cause of cancer-associated deaths among gynaecological malignancies. Increasing evidence suggests that microRNAs may be potential biomarkers for the diagnosis and prognosis of cancer. In this study, we conducted a systematic review and meta-analysis to summarize the global research and to evaluate the overall diagnostic accuracy of miRNAs in detecting ovarian cancer.

METHODS

A systematic literature search was conducted for relevant studies through July 20, 2017, in English databases (CENTRAL, MEDLINE, and EMBASE), the Grey reference database and Chinese databases. Statistical analysis was conducted using OpenMetaAnalyst, STATA 14.0 and RevMan 5.3. Pooled sensitivity, specificity, and other parameters were used to assess the overall miRNA assay performance using a bivariate random-effects model (BRM). Meta-regression and subgroup analyses were performed to dissect the heterogeneity. Sensitivity analysis was performed to assess the robustness of our analysis, and the publication bias of the selected studies was assessed using Deeks' funnel plot asymmetry test.

RESULTS

Thirteen articles described 33 studies, including 1081 patients with ovarian cancer and 518 controls. The pooled results were as follows: sensitivity, 0.89 (95% CI: 0.84-0.93); specificity, 0.64 (95% CI: 0.56-0.72); positive likelihood ratio, 2.18 (95% CI: 1.89-2.51); negative likelihood ratio, 0.15 (95% CI: 0.11-0.22); and diagnostic odds ratio (DOR), 13.21 (95% CI: 9.00-19.38). We conducted subgroup analyses based on ethnicity, research design, and miRNA profiling and found that multiple miRNA panels were more accurate in detecting ovarian cancer, with a combined DOR of 30.06 (95% CI: 8.58-105.37).

CONCLUSION

Per the meta-analysis, circulating miRNAs may be novel and non-invasive biomarkers for detecting ovarian cancer, particularly multiple miRNA panels, which have potential diagnostic value as screening tools in clinical practice.

Circulating microRNAs as novel potential diagnostic biomarkers for ovarian cancer: a systematic review and updated meta-analysis

Object

Ovarian cancer is the primary cause of cancer-associated deaths among gynaecological malignancies. Increasing evidence suggests that microRNAs may be potential biomarkers for the diagnosis and prognosis of cancer. In this study, we conducted a systematic review and meta-analysis to summarize the global research and to evaluate the overall diagnostic accuracy of miRNAs in detecting ovarian cancer.

Methods

A systematic literature search was conducted for relevant studies through July 20, 2017, in English databases (CENTRAL, MEDLINE, and EMBASE), the Grey reference database and Chinese databases. Statistical analysis was conducted using OpenMetaAnalyst, STATA 14.0 and RevMan 5.3. Pooled sensitivity, specificity, and other parameters were used to assess the overall miRNA assay performance using a bivariate random-effects model (BRM). Meta-regression and subgroup analyses were performed to dissect the heterogeneity. Sensitivity analysis was performed to assess the robustness of our analysis, and the publication bias of the selected studies was assessed using Deeks’ funnel plot asymmetry test.

Results

Thirteen articles described 33 studies, including 1081 patients with ovarian cancer and 518 controls. The pooled results were as follows: sensitivity, 0.89 (95% CI: 0.84–0.93); specificity, 0.64 (95% CI: 0.56–0.72); positive likelihood ratio, 2.18 (95% CI: 1.89–2.51); negative likelihood ratio, 0.15 (95% CI: 0.11–0.22); and diagnostic odds ratio (DOR), 13.21 (95% CI: 9.00–19.38). We conducted subgroup analyses based on ethnicity, research design, and miRNA profiling and found that multiple miRNA panels were more accurate in detecting ovarian cancer, with a combined DOR of 30.06 (95% CI: 8.58–105.37).

Conclusion

Per the meta-analysis, circulating miRNAs may be novel and non-invasive biomarkers for detecting ovarian cancer, particularly multiple miRNA panels, which have potential diagnostic value as screening tools in clinical practice.

Electronic supplementary material

The online version of this article (10.1186/s13048-019-0482-8) contains supplementary material, which is available to authorized users.