Identification of endometrioid endometrial carcinoma-associated microRNAs in tissue and plasma

Development of a necroptosis-related prognostic model for uterine corpus endometrial carcinoma

Necroptosis is a recently identified caspase-independent form of cell death which plays a significant role in the onset and progression of cancer. MicroRNAs (miRNAs) are vital for the development of uterine corpus endometrial carcinoma (UCEC) because they are an important regulatory component in necroptosis. This study developed a new necroptosis-related miRNAs profile to predict the prognosis of patients with UCEC. The TCGA-UCEC cohort's RNA sequencing data, consisting of 534 tumor samples and 33 normal samples, was downloaded. Ten differentially expressed miRNAs related to necroptosis were identified. A prediction model for necroptosis-related miRNAs was then created through COX regression and nomograms analysis. Clinical and pathological parameters were integrated to construct a nomogram and evaluate the model. Prognosis-related miRNAs were further used to predict target genes, and functional analysis was conducted to explore the potential mechanisms of these target genes. Subsequently, immune infiltration analysis was performed using transcriptome data to identify immune genes associated with prognosis, and the expression levels of target gene was validated using UCEC tissues. We identified 7 up-regulated miRNAs (hsa-miR-577, hsa-miR-7-5p, hsa-miR-210-3p, hsa-miR-210-5p, hsa-miR-200a-5p, hsa-miR-141-3p, hsa-miR-425-5p) and 3 down-regulated miRNAs (hsa-miR-7-2-3p, hsa-miR-383-5p, hsa-miR-29a-3p). The risk signature was based on univariate and multivariate COX analyses, constructed using 2 independent prognostic factors and miRNAs (hsa-miR-425-5p, hsa-miR-7-5p) associated with necroptosis. Nomograms demonstrated the prognostic value of risk level, age, FIGO stage, and histological type. Kaplan-Meier analysis revealed significant differences in overall survival (OS) outcomes associated with the expression of hsa-miR-425-5p (P < 0.001) and hsa-miR-7-5p (P = 0.015). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) investigations indicated that these miRNAs play crucial roles in tumor development, metastasis, and prognosis. Immune infiltration analysis showed decreased infiltration of CD8+ T cells, CD8+ T cells, NK cells, and M1 macrophages in normal tissues. Subsequently, a necroptosis-related immune gene significantly associated with prognosis (THRB) was identified, western blot and immunohistochemical staining confirmed the differential expression of THRB in normal endometrial tissues and tumor. Our findings demonstrate a close association between necroptosis and UCEC. The two necroptosis-related miRNAs used in this study may serve as valuable prognostic markers for UCEC patients, and are associated with immune cell infiltration. This suggests that necroptosis may be involved in the development of UCEC through its interaction with immune responses.

Circulating miRNAs as a Tool for Early Diagnosis of Endometrial Cancer-Implications for the Fertility-Sparing Process: Clinical, Biological, and Legal Aspects

This review article explores the possibility of developing an integrated approach to the management of the different needs of endometrial cancer (EC) patients seeking to become pregnant. Life preservation of the woman, health preservation of the baby, a precocious and-as much as possible-minimally invasive characterization of the health and fertility parameters of the patient, together with the concerns regarding the obstetric, neonatal, and adult health risks of the children conceived via assisted reproductive techniques (ART) are all essential aspects of the problem to be taken into consideration, yet the possibility to harmonize such needs through a concerted and integrated approach is still very challenging. This review aims to illustrate the main features of EC and how it affects the normal physiology of pre-menopausal women. We also focus on the prospect of a miR-based, molecular evaluation of patient health status, including both EC early diagnosis and staging and, similarly, the receptivity of the woman, discussing the possible evaluation of both aspects using a single specific panel of circulating miRs in the patient, thus allowing a relatively fast, non-invasive testing with a significantly reduced margin of error. Finally, the ethical and legal/regulatory aspects of such innovative techniques require not only a risk-benefit analysis; respect for patient autonomy and equitable health care access allocation are fundamental issues as well.

Circulating and Endometrial Tissue microRNA Markers Associated with Endometrial Cancer Diagnosis, Prognosis, and Response to Treatment

In developed countries, endometrial cancer (EC) is one of the most common neoplasms of the female reproductive system. MicroRNAs (miRs) are a class of single-stranded noncoding RNA molecules with lengths of 19-25 nucleotides that bind to target messenger RNA (mRNA) to regulate post-transcriptional gene expression. Although there is a large amount of research focused on identifying miRs with a diagnostic, prognostic, or response to treatment capacity in EC, these studies differ in terms of experimental methodology, types of samples used, selection criteria, and results obtained. Hence, there is a large amount of heterogeneous information that makes it difficult to identify potential miR biomarkers. We aimed to summarize the current knowledge on miRs that have been shown to be the most suitable potential markers for EC. We searched PubMed and Google Scholar without date restrictions or filters. We described 138 miRs with potential diagnostic, prognostic, or treatment response potential in EC. Seven diagnostic panels showed higher sensitivity and specificity for the diagnosis of EC than individual miRs. We further identified miRs up- or downregulated depending on the FIGO stage, precursor lesions, and staging after surgery, which provides insight into which miRs are expressed chronologically depending on the disease stage and/or that are modulated depending on the tumor grade based on histopathological evaluation.

Recent Updates on the Role of the MicroRNA-10 Family in Gynecological Malignancies

The ever-increasing morbidity associated with gynecological malignancies constantly endangers the physical and psychological health of women. Since a long time, there has been an urgent need for a deeper understanding of the tumorigenesis and the development of gynecological cancer to identify new molecular markers for early diagnosis and metastatic disease prognosis and for the development of therapeutic targets. MicroRNAs are crucial cellular regulators. The microRNA-10 (miR-10) family has been found to play an integral role in the evolution of numerous cancer types. A comprehensive understanding of current studies on miR-10 could provide better insights into future research and clinical applications in related fields. This article reviews the latest research on the role of the miR-10 family in gynecological malignancies and the relevant molecular mechanism, mainly focusing on endometrial, cervical, and ovarian cancers.

miRNAs Participate in the Regulation of Oxidative Stress-Related Gene Expression in Endometrioid Endometrial Cancer

Reactive oxygen species are formed as by-products of normal cell metabolism. They are needed to maintain cell homeostasis and signaling, which is possible due to defense systems. Disruption of this balance leads to oxidative stress that can induce cancer. Redox regulation by miRNAs may be a potential therapeutic target. The aim of the study was to assess the activity of genes associated with oxidative stress in endometrial cancer and to determine their relationship with miRNAs. The study included 45 patients with endometrioid endometrial cancer and 45 without neoplastic changes. The expression profile of genes associated with oxidative stress was determined with mRNA microarrays, RT-qPCR and ELISA. The miRNA prediction was performed based on the miRNA microarray experiment and the mirDB tool. PRDX2 and AQP1 showed overexpression that was probably not related to miRNA activity. A high level of PKD2 may be the result of a decrease in the activity of miR-195-3p, miR-20a, miR-134. A SOD3 level reduction can be caused by miR-328, miR-363. In addition, miR-363 can also regulate KLF2 expression. In the course of endometrial cancer, the phenomenon of oxidative stress is observed, the regulation of which may be influenced by miRNAs.

Diagnostic Accuracy of Liquid Biomarkers for the Non-Invasive Diagnosis of Endometrial Cancer: A Systematic Review and Meta-Analysis

Endometrial cancer rates are increasing annually due to an aging population and rising rates of obesity. Currently there is no widely available, accurate, non-invasive test that can be used to triage women for diagnostic biopsy whilst safely reassuring healthy women without the need for invasive assessment. The aim of this systematic review and meta-analysis is to evaluate studies assessing blood and urine-based biomarkers as a replacement test for endometrial biopsy or as a triage test in symptomatic women. For each primary study, the diagnostic accuracy of different biomarkers was assessed by sensitivity, specificity, likelihood ratio and area under ROC curve. Forest plots of summary statistics were constructed for biomarkers which were assessed by multiple studies using data from a random-effect models. All but one study was of blood-based biomarkers. In total, 15 studies reported 29 different exosomal biomarkers; 34 studies reported 47 different proteomic biomarkers. Summary statistic meta-analysis was reported for micro-RNAs, cancer antigens, hormones, and other proteomic markers. Metabolites and circulating tumor materials were also summarized. For the majority of biomarkers, no meta-analysis was possible. There was a low number of small, heterogeneous studies for the majority of evaluated index tests. This may undermine the reliability of summary estimates from the meta-analyses. At present there is no liquid biopsy that is ready to be used as a replacement test for endometrial biopsy. However, to the best of our knowledge this is the first study to report and meta-analyze the diagnostic accuracy of different classes of blood and urine biomarkers for detection of endometrial cancer. This review may thus provide a reference guide for those wishing to explore candidate biomarkers for further research.

Clinical Value and Molecular Function of Circulating MicroRNAs in Endometrial Cancer Regulation: A Systematic Review

This systematic review of literature highlights the different microRNAs circulating in the serum or plasma of endometrial cancer patients and their association with clinical and prognostic characteristics in endometrial cancer. This study also investigates the molecular functions of these circulating microRNAs. According to this systematic review, a total of 33 individual circulating miRs (-9, -15b, -20b-5p, -21, -27a, -29b, -30a-5p, -92a, -99a, -100, -135b, -141, -142-3p, -143-3p, -146a-5p, -150-5p, -151a-5p, -186, -195-5p, -199b, -200a, -203, -204, -205, -222, -223, -301b, -423-3p, -449, -484, -887-5p, -1228, and -1290) and 6 different panels of miRs (“miR-222/miR-223/miR-186/miR-204”, “miR-142-3p/miR-146a-5p/miR-151a-5p”, “miR-143-3p/miR-195-5p/miR-20b-5p/miR-204-5p/miR-423-3p/miR-484”, “mir-9/miR-1229”, “miR-9/miR-92a”, and “miR-99a/miR-199b”) had a significant expression variation in EC patients compared to healthy patients. Also, seven individual circulating miRs (-9, -21, -27a, -29b, -99a, -142-3p, and -449a) had a significant expression variation according to EC prognostic factors such as the histological type and grade, tumor size, FIGO stage, lymph node involvement, and survival rates. One panel of circulating miRs (“-200b/-200c/-203/-449a”) had a significant expression variation according to EC myometrial invasion. Further studies are needed to better understand their function and circulation.

Can miRNAs be useful biomarkers in improving prognostic stratification in endometrial cancer patients? An update review

Endometrial cancer (EC) is the most common gynecological cancer, with annual incidence rates in Western countries ranging between 15 and 25 per 100 000 women. About 15% to 20% of patients with EC have high-risk disease and follow an aggressive clinical course. Unfortunately, the assessment of histologic parameters is poorly reproducible and conventional clinicopathological and molecular features do not reliably predict either the patient's response to the available treatments or the definition of personalized therapeutic approaches. In this context, the identification of novel diagnostic and prognostic biomarkers, which can be integrated in the current classification schemes, represents an unmet clinical need and an important challenge. miRNAs are key players in cancer by regulating the expression of specific target genes. Their role in EC, in association with clinical and prognostic tumor biomarkers, has been investigated but, so far, with little consensus among the studies. The present review aims to describe the recent advances in miRNAs research in EC taking into consideration the current classification schemes and to highlight the most promising miRNAs. Finally, a perspective point of view sheds light on the challenges ahead in the landscape of EC.

Liquid Biopsy for Monitoring EC Patients: Towards Personalized Treatment

Simple Summary

Although the field of liquid biopsy is clearly having an effect on other tumour types, in endometrial cancer (EC) there is important work to do to implement the analysis of circulating biomarkers into the clinical routine. One of the most evident contexts of application is the disease follow-up in both localized and advanced diseases, which at present is primarily made by imaging techniques. In the present review, we conducted an overview of the circulating biomarkers with the potential to be used as monitoring biomarkers in endometrial tumours and highlighted the key challenges for their translation into the patients’ management in order to help researchers to better focus their work in this field.

Abstract

Endometrial cancer (EC) is the most frequent gynecological cancer in developed countries and its incidence shows an increasing trend. Fortunately, the prognosis of the disease is good when the tumour is diagnosed in an early phase, but some patients recur after surgery and develop distant metastasis. The therapy options for EC for advanced disease are more limited than for other tumours. Therefore, the application of non-invasive strategies to anticipate the recurrence of localized tumours and guide the treatment in advanced stages represents a clear requirement to improve the survival and quality of life of patients with EC. To achieve this desired precision oncology, it is necessary to invest in the identification and validation of circulating markers that allow a more effective stratification and monitoring of patients. We here review the main advances made for the evaluation of circulating tumour DNA (ctDNA), circulating tumour cells (CTCs), circulating extracellular vesicles (cEVs), and other non-invasive biomarkers as a monitoring tool in the context of localized and advanced endometrial tumours, with the aim of providing a global perspective of the achievements and the key areas in which the use of these markers can be developed into a real clinical tool.

MicroRNAs as Predictors of Future Uterine Malignancy in Endometrial Hyperplasia without Atypia

The histological criteria for classifying endometrial hyperplasia (EH) are based on architectural crowding and nuclear atypia; however, diagnostic agreement among pathologists is poor. We investigated molecular biomarkers of endometrial cancer (EC) risk in women with simple hyperplasia or complex hyperplasia without atypia (SH/CH-nonA). Forty-nine patients with EC preceded by SH/CH-nonA were identified, of which 23 were excluded (15 with complex atypical hyperplasia (CAH), six not consenting, one with a diagnosis < 6 months prior, and one lost to follow-up). The EH tissues of these patients were compared with those of patients with SH/CH-nonA that did not progress to EC (control) through microRNA (miRNA) array analysis, and the results were verified in an expanded cohort through reverse transcription-quantitative polymerase chain reaction (RT-qPCR). MiRNA arrays analyses revealed 20 miRNAs that differed significantly (p < 0.05, fold change > 4) between the control (n = 12) and case (n = 6) patients. Multiplex RT-qPCR for the 20 miRNAs in the expanded cohort (94 control and 25 case patients) led to the validation of miR-30a-3p (p = 0.0009), miR-141 (p < 0.0001), miR-200a (p < 0.0001), and miR-200b (p < 0.0001) as relevant biomarkers, among which miR-141, miR-200a, and miR-200b regulate the expression of phosphatase and tensin homolog (PTEN). For the prediction of EC, the area under the curve for miR-30a-3p, miR-141, miR-200a, and miR-200b was 0.623, 0.754, 0.783, and 0.704, respectively. The percentage of complete PTEN loss was significantly higher in the case group than in the control group (24% vs. 0%, p < 0.001, Fisher’s exact test). A combination of complete PTEN loss and miR-200a provided optimal prediction performance (sensitivity = 0.760; specificity = 1.000; positive predictive value = 1.000; negative predictive value = 0.937; accuracy = 0.947). MiR-30a-3p, miR-141, miR-200a, miR-200b, and complete PTEN loss may be useful tissue biomarkers for predicting EC risk among patients with SH/CH-nonA.

New Trends in the Detection of Gynecological Precancerous Lesions and Early-Stage Cancers

The prevention and early diagnostics of precancerous stages are key aspects of contemporary oncology. In cervical cancer, well-organized screening and vaccination programs, especially in developed countries, are responsible for the dramatic decline of invasive cancer incidence and mortality. Cytological screening has a long and successful history, and the ongoing implementation of HPV triage with increased sensitivity can further decrease mortality. On the other hand, endometrial and ovarian cancers are characterized by a poor accessibility to specimen collection, which represents a major complication for early diagnostics. Therefore, despite relatively promising data from evaluating the combined effects of genetic variants, population screening does not exist, and the implementation of new biomarkers is, thus, necessary. The introduction of various circulating biomarkers is of potential interest due to the considerable heterogeneity of cancer, as highlighted in this review, which focuses exclusively on the most common tumors of the genital tract, namely, cervical, endometrial, and ovarian cancers. However, it is clearly shown that these malignancies represent different entities that evolve in different ways, and it is therefore necessary to use different methods for their diagnosis and treatment.

miRNAs in the Expression Regulation of Dopamine-Related Genes and Proteins in Endometrial Cancer

Disruption of the dopaminergic system leads to many diseases, including cancer. Dopamine and its receptors are involved in the regulation of proliferation, cell death, invasion, and migration. Better understanding of the mechanisms involved in these processes could reveal new molecular markers and therapeutic targets. The aim of this study was to determine the expression profile of dopamine-related genes and proteins in endometrial cancer and to assess whether miRNAs are involved in its regulation. Sixty women were recruited for the study: 30 with endometrial cancer and 30 without cancer. The expression profiles of dopamine-related genes were determined in endometrial tissue samples using microarrays and qRT-PCR. Then, protein concentration was determined with the ELISA test. In the last step, miRNA detection was performed using microarrays. The matching of miRNAs to the studied genes was carried out using the TargetScan tool. The analysis showed DRD2 and DRD3 overexpression, with a reduction in DRD5 expression, which could be due to miR-15a-5p, miR-141-3p, miR-4640-5p, and miR-221-5p activity. High levels of OPRK1 and CXCL12, related to the activity of miR-124-3p.1 and miR-135b-5p, have also been reported. Low COMT expression was probably not associated with miRNA regulation in endometrial cancer.

The Role of miRNAs in the Regulation of Endometrial Cancer Invasiveness and Metastasis-A Systematic Review

Endometrial cancer (EC) is the most common genital cancer in women with increasing death rates. MiRNAs are short non-coding RNAs that regulate gene expression on the post-transcriptional levels. Multiple studies demonstrated a fundamental role of miRNAs in the regulation of carcinogenesis. This systematic review is a comprehensive overview of the role of miRNAs in the regulation of cancer cell invasiveness and metastasis in EC. The literature was searched for studies investigating the role of miRNAs in the regulation of invasiveness and metastasis in EC. We explored PubMed, Embase, and Scopus using the following keywords: miRNA, metastasis, invasiveness, endometrial cancer. Data were collected from 163 articles that described the expression and role of 106 miRNAs in the regulation of EC invasiveness and metastasis out of which 63 were tumor suppressor miRNAs, and 38 were oncomiRNAs. Five miRNAs had a discordant role in different studies. Moreover, we identified 66 miRNAs whose expression in tumor tissue or concentration in serum correlated with at least one clinical parameter. These findings suggest a crucial role of miRNAs in the regulation of EC invasiveness and metastasis and present them as potential prognostic factors for patients with EC.

MicroRNA expression profile in serum reveals novel diagnostic biomarkers for endometrial cancer

Purpose: Circulating microRNAs (miRNAs) prove to be promising diagnostic biomarkers for various cancers, including endometrial cancer (EC). The present study aims to identify serum microRNAs that can serve as potential biomarkers for EC diagnosis.

Patients and methods: A total of 92 EC and 102 normal control (NC) serum samples were analyzed using quantitative real-time polymerase chain reaction (qRT-PCR) in this four-phase experiment. The logistic regression method was used to construct a diagnostic model based on the differentially expressed miRNAs in serum. The receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic value. To further validate the diagnostic capacity of the identified signature, the 6-miRNA marker was compared with previously reported biomarkers and verified in three public datasets. In addition, the expression characteristics of the identified miRNAs were further explored in tissue and serum exosomes samples.

Results: Six miRNAs (miR-143-3p, miR-195-5p, miR-20b-5p, miR-204-5p, miR-423-3p, and miR-484) were significantly overexpressed in the serum of EC compared with NCs. Areas under the ROC of the 6-miRNA signatures were 0.748, 0.833, and 0.967 for the training, testing, and the external validation phases, respectively. The identified signature has a very stable diagnostic performance in the large cohorts of three public datasets. Compared with previously identified miRNA biomarkers, the 6-miRNA signature in the present study has superior performance in diagnosing EC. Moreover, the expression of miR-143-3p and miR-195-5p in tissues and the expression of miR-20b-5p in serum exosomes were consistent with those in serum.

Conclusions: We established a 6-miRNA signature in serum and they could function as potential non-invasive biomarker for EC diagnosis.

Identification of a MicroRNA Signature Associated With Lymph Node Metastasis in Endometrial Endometrioid Cancer

Background

Lymph node metastasis (LNM) is an important prognostic factor in endometrial cancer. Anomalous microRNAs (miRNAs) are associated with cell functions and are becoming a powerful tool to characterize malignant transformation and metastasis. The aim of this study was to construct a miRNA signature to predict LNM in endometrial endometrioid carcinoma (EEC).

Method

Candidate target miRNAs related to LNM in EEC were screened by three methods including differentially expressed miRNAs (DEmiRs), weighted gene co-expression network analysis (WGCNA), and decision tree algorithms. Samples were randomly divided into the training and validation cohorts. A miRNA signature was built using a logistic regression model and was evaluated by the area under the curve (AUC) of receiver operating characteristic curve (ROC) and decision curve analysis (DCA). We also conducted pathway enrichment analysis and miRNA-gene regulatory network to look for potential genes and pathways engaged in LNM progression. Survival analysis was performed, and the miRNAs were tested whether they expressed differently in another independent GEO database.

Result

Thirty-one candidate miRNAs were screened and a final 15-miRNA signature was constructed by logistic regression. The model showed good calibration in the training and validation cohorts, with AUC of 0.824 (95% CI, 0.739-0.912) and 0.821 (95% CI, 0.691-0.925), respectively. The DCA demonstrated the miRNA signature was clinically useful. Hub miRNAs in signature seemed to contribute to EEC progression via mitotic cell cycle, cellular protein modification process, and molecular function. MiR-34c was statistically significant in survival that a higher expression of miR-34c indicated a higher survival time. MiR-34c-3p, miR-34c-5p, and miR-34b-5p were expressed differentially in GSE75968.

Conclusion

The miRNA signature could work as a noninvasive method to detect LNM in EEC with a high prediction accuracy. In addition, miR-34c cluster may be a key biomarker referring LNM in endometrial cancer.

Usefulness of microRNA detection in the diagnostics of endometrial cancer

INTRODUCTION

MicroRNAs (miRNAs) are noncoding RNAs that regulate gene expression and contribute to the development of cancer. They have been shown to be stable in tissue samples and may be promising diagnostic biomarkers for endometrial cancer.

MATERIAL AND METHODS

A retrospective cohort study of women diagnosed with endometrial cancer between January 2017 and December 2017 was performed at the Royal Cornwall Hospital. Archived formalin-fixed paraffin-embedded samples were obtained from patients with endometrial cancer and healthy women. MicroRNA was isolated and quantitative real-time polymerase chain reaction was used to detect expression levels of miRNAs.

RESULTS

A total of 76 women were included: 36 endometrial cancer patients, 40 healthy controls. A distinct panel of miR-200a, miR-200b, miR-200c, miR-205, and miR-182 showed an area under the curve of 0.958, sensitivity 92%, specificity 89%, positive predictive value of 89% (95% CI 82%-94%) and negative predictive value of 91% (95% CI 85%-96%) in diagnosing endometrial cancer. High miR-182 expression levels were significantly related to high-grade endometrioid tumors compared with low-grade tumors.

CONCLUSIONS

We demonstrated high diagnostic accuracy of miRNA for detecting endometrial cancer. In addition, miRNA contributed to an improvement in distinguishing between high-grade and low-grade endometrioid tumors.

MicroRNA as Epigenetic Modifiers in Endometrial Cancer: A Systematic Review

Simple Summary

Endometrial cancer (EC) is the 2nd most common gynecologic cancer worldwide. MicroRNAs (miRNAs) are small noncoding RNAs that contribute to epigenetic regulation. The objective of this systematic review is to summarize our current knowledge on the role of miRNAs in the epigenetic deregulation of tumor-related genes in EC. It includes all miRNAs reported to be involved in EC including their roles in DNA methylation and RNA-associated silencing. This systematic review should be useful for development of novel strategies to improve diagnosis and risk assessment as well as for new treatments aimed at miRNAs, their target genes or DNA methylation.

Abstract

The objective of this systematic review is to summarize our current knowledge on the influence of miRNAs in the epigenetic deregulation of tumor-related genes in endometrial cancer (EC). We conducted a literature search on the role of miRNAs in the epigenetic regulation of EC applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following terms were used: microRNA, miRNA, miR, endometrial cancer, endometrium, epigenetic, epimutation, hypermethylation, lynch, deacetylase, DICER, novel biomarker, histone, chromatin. The miRNAs were classified and are presented according to their function (tumor suppressor or onco-miRNA), their targets (when known), their expression levels in EC tissue vs the normal surrounding tissue, and the degree of DNA methylation in miRNA loci and CpG sites. Data were collected from 201 articles, including 190 original articles, published between November 1, 2008 and September 30, 2020 identifying 313 different miRNAs implicated in epigenetic regulation of EC. Overall, we identified a total of 148 miRNAs with decreased expression in EC, 140 miRNAs with increased expression in EC, and 22 miRNAs with discordant expression levels. The literature implicated different epigenetic phenomena including altered miRNA expression levels (miR-182, -230), changes in the methylation of miRNA loci (miR-34b, -129-2, -130a/b, -152, -200b, -625) and increased/decreased methylation of target genes (miR-30d,-191). This work provides an overview of all miRNAs reported to be involved in epigenetic regulation in EC including DNA methylation and RNA-associated silencing. These findings may contribute to novel strategies in diagnosis, risk assessment, and treatments aimed at miRNAs, their target genes or DNA methylation.

Low Expression of miR-375 and miR-190b Differentiates Grade 3 Patients with Endometrial Cancer

Endometrial cancer (EC) is treated according to the stage and prognostic risk factors. Most EC patients are in the early stages and they are treated surgically. However some of them, including those with high grade (grade 3) are in the intermediate and high intermediate prognostic risk groups and may require adjuvant therapy. The goal of the study was to find differences between grades based on an miRNA gene expression profile. Tumor samples from 24 patients with grade 1 (n = 10), 2 (n = 7), and 3 (n = 7) EC were subjected to miRNA profiling using next generation sequencing. The results obtained were validated using the miRNA profile of 407 EC tumors from the external Cancer Genome Atlas (TCGA) cohort. We obtained sets of differentially expressed (DE) miRNAs with the largest amount between G2 to G1 (50 transcripts) and G3 to G1 (40 transcripts) patients. Validation of our results with external data (TCGA) gave us a reasonable gene overlap of which we selected two miRNAs (miR-375 and miR190b) that distinguish the high grade best from the low grade EC. Unsupervised clustering showed a high degree of heterogeneity within grade 2 samples. MiR-375 as well as 190b might be useful to create grading verification test for high grade EC. One of the possible mechanisms that is responsible for the high grade is modulation by virus of host morphology or physiology.

microRNA-499a promotes the progression and chemoresistance of cervical cancer cells by targeting SOX6

Emerging evidence has indicated that microRNAs are involved in multiple processes of cancer development. Previous studies have demonstrated that microRNA-499a (miR-499a) plays both oncogenic and tumor suppressive roles in several types of malignancies, and genetic variants in miR-499a are associated with the risk of cervical cancer. However, the biological roles of miR-499a in cervical cancer have not been investigated. Quantitative real-time PCR was used to assess miR-499a expression in cervical cancer cells. Mimics or inhibitor of miR-499a was transfected into cervical cancer cells to upregulate or downregulate miR-499a expression. The effects of miR-499a expression change on cervical cancer cells proliferation, colony formation, tumorigenesis, chemosensitivity, transwell migration and invasion were assessed. The potential targets of miR-499a were predicted using online database tools and validated using real-time PCR, Western blot and luciferase reporter experiments. miR-499a was significantly upregulated in cervical cancer cells. Moreover, overexpression of miR-499a significantly enhanced the proliferation, cell cycle progression, colony formation, apoptosis resistance, migration and invasion of cervical cancer cells, while inhibiting miR-499a showed the opposite effects. Further exploration demonstrated that Sex-determining region Y box 6 was the direct target of miR-499a. miR-499a-induced SOX6 downregulation mediated the oncogenic effects of miR-499a in cervical cancer. Inhibiting miR-499a could enhance the anticancer effects of cisplatin in the xenograft mouse model of cervical cancer. Our findings for the first time suggest that miRNA-499a may play an important role in the development of cervical cancer and could serve as a potential therapeutic target.

Circulating Extracellular Vesicles in Gynecological Tumors: Realities and Challenges

Although liquid biopsy can be considered a reality for the clinical management of some cancers, such as lung or colorectal cancer, it remains a promising field in gynecological tumors. In particular, circulating extracellular vesicles (cEVs) secreted by tumor cells represent a scarcely explored type of liquid biopsy in gynecological tumors. Importantly, these vesicles are responsible for key steps in tumor development and dissemination and are recognized as major players in cell-to-cell communication between the tumor and the microenvironment. However, limited work has been reported about the biologic effects and clinical value of EVs in gynecological tumors. Therefore, here we review the promising but already relatively limited data on the role of circulating EVs in promoting gynecological tumor spread and also their value as non-invasive biomarkers to improve the management of these type of tumors.

Mutually distinguishing microRNA signatures of breast, ovarian and endometrial cancers in vitro

Early diagnosis and therapy in the first stages of a malignant disease is the most crucial factor for successful cancer treatment and recovery. Currently, there is a high demand for novel diagnostic tools that indicate neoplasms in the first or pre‑malignant stages. MicroRNAs (miRNA or miR) are small non‑coding RNAs that may act as oncogenes and downregulate tumor‑suppressor genes. The detection and mutual discrimination of the three common female malignant neoplasia types breast (BC), ovarian (OC) and endometrial cancer (EC) could be enabled by identification of tumor entity‑specific miRNA expression differences. In the present study, the relative expression levels of 25 BC, EC and OC‑related miRNAs were assessed by reverse transcription‑quantitative PCR and determined using the 2‑ΔΔCq method for normalization against the mean of four housekeeping genes. Expression levels of all miRNAs were analyzed by regression against cell line as a factor. An expression level‑based discrimination between BC and OC cell types was obtained for a subgroup of ten different miRNA types. miR‑30 family genes, as well as three other miRNAs, were found to be uniformly upregulated in OC cells compared with BC cells. BC and EC cells could be distinguished by the expression profiles of six specific miRNAs. In addition, four miRNAs were differentially expressed between EC and OC cells. In conclusion, miRNAs were identified as a potential novel tool to detect and mutually discriminate between BC, OC and EC. Based on a subset of 25 clinically relevant human miRNA types, the present study could significantly discriminate between these three female cancer types by means of their expression levels. For further verification and validation of miRNA‑based biomarker expression signatures that enable valuable tumor detection and characterization in routine screening or potential therapy monitoring, additional and extended in vitro analyses, followed by translational studies utilizing patients' tissue and liquid biopsy materials, are required.

Bioinformatic screening for candidate biomarkers and their prognostic values in endometrial cancer

BACKGROUND

Endometrial cancer is a common gynecological cancer with annually increasing incidence worldwide. However, the biomarkers that provide prognosis and progression for this disease remain elusive.

RESULTS

Two eligible human endometrial cancer datasets (GSE17025 and GSE25405) were selected for the study. A total of 520 differentially expressed mRNAs and 30 differentially expressed miRNAs were identified. These mRNAs were mainly enriched in cell cycle, skeletal system development, vasculature development, oocyte maturation, and oocyte meiosis signalling pathways. A total of 160 pairs of differentially expressed miRNAs and mRNAs, including 22 differentially expressed miRNAs and 71 overlapping differentially expressed mRNAs, were validated in endometrial cancer samples using starBase v2.0 project. The prognosis analysis revealed that Cyclin E1 (CCNE1, one of the 82 hub genes, which correlated with hsa-miR-195 and hsa-miR-424) was significantly linked to a worse overall survival in endometrial cancer patients.

CONCLUSIONS

The hub genes and differentially expressed miRNAs identified in this study might be used as prognostic biomarkers for endometrial cancer and molecular targets for its treatment.

Discovery of potential serum and urine-based microRNA as minimally-invasive biomarkers for breast and gynecological cancer

BACKGROUND

Deregulated microRNAs (miRNAs) in breast and gynecological cancer might contribute to improve early detection of female malignancies.

OBJECTIVE

Specification of miRNA types in serum and urine as minimally-invasive biomarkers for breast (BC), endometrial (EC) and ovarian cancer (OC).

METHODS

In a discovery phase, serum and urine samples from 17 BC, five EC and five OC patients vs. ten healthy controls (CTRL) were analyzed with Agilent human miRNA microarray chip. Selected miRNA types were further investigated by RT-qPCR in serum (31 BC, 13 EC, 15 OC patients, 32 CTRL) and urine (25 BC, 10 EC, 10 OC patients, 30 CTRL) applying two-sample t-tests.

RESULTS

Several miRNA biomarker candidates exhibited diagnostic features due to distinctive expression levels (serum: 26; urine: 22). Among these, miR-518b, -4719 and -6757-3p were found specifically deregulated in BC serum. Four, non-entity-specific, novel biomarker candidates with unknown functional roles were identified in urine (miR-3973; -4426; -5089-5p and -6841). RT-qPCR identified miR-484/-23a (all p⩽ 0.001) in serum as potential diagnostic markers for EC and OC while miR-23a may also serve as an endogenous control in BC diagnosis.

CONCLUSIONS

Promising miRNAs as liquid biopsy-based tools in the detection of BC, EC and OC qualified for external validation in larger cohorts.

Diagnostic value of microRNA panel in endometrial cancer: A systematic review

PURPOSE

We conducted a systematic review to evaluate the overall diagnostic accuracy of miRNAs in detecting endometrial cancer.

MATERIALS AND METHODS

A systematic search of Medline, Embase, Cinahl and the Cochrane Controlled Register of Trials was performed to identify studies reporting on the diagnostic value of miRNA in EC patients. Included were diagnostic studies looking at miRNA expression in women diagnosed with endometrial cancer. Two reviewers independently selected studies and assessed quality of studies using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) score system. Data extraction was completed and the vote-counting strategy was used to rank miRNAs.

RESULTS

26 studies were included with a total number of 1,400 EC patients reporting on 106 differentially expressed miRNAs. The most frequently found up-regulated miRNA was miR-205 followed by miR-200c, -223, -182, -183 and -200a. In addition, miR-135b, miR-429, miR-141 and miR-200b were also frequently up-regulated. There was less consensus on down-regulated miRNAs.

CONCLUSIONS

miRNAs yield a promising diagnostic biomarker potential in endometrial cancer, especially miR-205, the miR-200 family and miR-135b, -182, -183 and -223. However, no sufficient high quality data are available to draw hard conclusions. More research is needed to validate the diagnostic potential of these miRNAs in larger studies. In addition, the potential of urine as a non-invasive biofluid should be investigated in more detail.

Suppression of miR-30a-3p Attenuates Hepatic Steatosis in Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease (NAFLD) have a high prevalence in humans in the past two decades. Here, we elucidated the functions of miR-30a-3p in the development of NAFLD and identified its potential targets. HepG-2 cells and NAFLD patients' blood samples were used in our study. Bioinformatics analysis as well as luciferase reporter assays were employed to distinguish peroxisome proliferator-activated receptor alpha (PPAR-α) as a target gene. Western blotting showed the expressions of lipid metabolic proteins and the target gene PPAR-α. Oil red O staining and triglyceride activity tested the fatty deposits after treatment with miR-30a-3p. miR-30a-3p was substantially up-regulated in NAFLD. Bioinformatics analyses showed that PPAR-α was a possible target of miR-30a-3p, linked with signaling pathways in NAFLD. PPAR-α as a novel target of miR-30a-3p, and suppression of its levels. The lipid metabolic-related proteins ACC, p-GSK-3β and FASN were up-regulated after transfecting with miR-30a-3p mimic, but the proteins CPT1, p-AMPK and UCP2 were down-regulated. miR-30a-3p inhibitor could diminish the protein manifestation of ACC, p-GSK-3β and FASN; and augment the protein manifestation of CPT1, p-AMPK and UCP2. On the contrary, overexpression of miR-30a-3p had adverse impacts on the performance of hepatocellular lipid accumulation and Triglyceride (TG) activity. Co-treatment with miR-30a-3p mimic and overexpression PPAR-α could revise the hepatic steatosis and the TG level induced by fat milk. Our findings suggest that miR-30a-3p/PPAR-α may be developed as a potential agent in NAFLD, which is enough to attenuate triglyceride accumulation and hepatic steatosis.

Circulating Transcripts and Biomarkers in Uterine Tumors: Is There a Predictive Role?

PURPOSE OF REVIEW

Uterine cancer comprises endometrial carcinoma and the uterine sarcoma. Endometrial carcinomas are the most frequent variant and have early symptoms and a solid diagnostic work up, resulting in a rather fair prognosis. However, in case of advanced stage disease and relapse, treatment options are limited and prognosis is impaired. Uterine sarcomas are rare, often lacking symptoms and no diagnostic tool for correct pre-operative diagnosis are available. Prognosis is poor.

RECENT FINDINGS

Circulating biomarkers as a liquid biopsy could be beneficial as a diagnostic tool in uterine sarcomas. For both carcinomas and sarcomas, circulating biomarkers could be of use in predicting early disease recurrence. This review in endometrial carcinoma and uterine sarcoma focus on circulating biomarkers; such as proteins; circulating tumor cells; circulating tumor DNA; microRNA; and immune cells.

Downregulations of miR-449a and miR-145-5p Act as Prognostic Biomarkers for Endometrial Cancer

This investigation aimed to explore the underlying prognosis-associated microRNA (miRNA) biomarkers in endometrial cancer. Homo sapiens miRNA data set GSE35794 and miRNA data in TGGA database were downloaded and applied to screen the differentially expressed miRNAs (DE-miRNAs) using unpaired t-test in limma package in R. Basing on Venn analysis, the overlapped DE-miRNAs were screened and their potential targets were predicted according to miRWalk followed by target functional enrichment analyses and protein-protein interaction network visualized using Cytoscape. Finally, according to the information provided by the The Cancer Genome Atlas (TCGA) database, correlations between miRNAs or targets and patient prognosis were analyzed by survival package in R. A total of 24 overlapped DE-miRNAs were identified between endometrioid endometrial cancer samples and normal samples. Then, the miRNA-target regulatory network was constructed, including 11 upregulated miRNAs (e.g., miR-200a, miR-200b, and miR-200c) and five downregulated miRNAs (e.g., miR-449a, miR-145-5p, and miR-145-3p). Lymphocyte enhancer factor-1 (LEF1) was predicted to be a target of miR-449a and SOX11 was a target of miR-145-5p. Functional enrichment analyses of these targets were significantly related to the biological process of "negative regulation of transcription from RNA polymerase II promoter" and "positive regulation of transcription from RNA polymerase II promoter" (e.g., NOTCH1, LEF1, and SOX11). In addition, survival analysis showed that miR-449a, miR-145-5p, and LEF1 were approximately correlated with the overall survival prognosis of endometrial cancer patients. Downregulations of miR-449a and miR-145-5p might be involved in the pathogenesis of endometrial cancer and could act as prognostic biomarkers for endometrial cancer patients.

MicroRNA‑195 inhibits epithelial‑mesenchymal transition by targeting G protein‑coupled estrogen receptor 1 in endometrial carcinoma

Epithelial-mesenchymal transition (EMT) has been shown to exert promoting effects on the progression of a number of cancer types, including endometrial carcinoma (EC). MicroRNA (miRNA or miR)-195 has been shown to function as a tumor suppressor. This study aimed to explore the potential role of miR-195 in the EMT process of EC. miR-195 overexpression (Mimics) and mimics control (Mock) vectors were constructed and transfected into human endometrial cancer cells (AN3-CA and Hec1A) using Lipofectamine 2000, and cell viability was detected using the Cell Counting kit-8 (CCK-8). The invasive and migratory capacities of the cells transfected with the Mimics or Mock vectors were assessed by Transwell and wound healing assays. Relative mRNA and protein levels were analyzed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, respectively. Using TargetScan prediction, the potential target of miR-195 was identified and was further verified by dual-luciferase reporter assay. Following transfection with miR-195 mimics, the viability of the AN3-CA and Hec1A cells decreased in a time-dependent manner, specifically at 24 h. The wound closure rate and the number of invaded cells in the Mimics group were much lower than those in the Control and Mock groups (P<0.01). miR-195 overexpression significantly upregulated the mRNA and protein levels of tissue inhibitor of metalloproteinase 2 (TIMP-2), while it downregulated the expression levels of matrix metalloproteinase (MMP)-2 and MMP-9. Moreover, the phosphorylation levels of PI3K and AKT were also notably decreased (P<0.01). G protein-coupled estrogen receptor 1 (GPER) was identified as a target of miR-195. On the whole, the findings of this study indicate that the inhibitory effects of miR195 on EC cell migration and invasion are associated with the PI3K/AKT signaling pathway and GPER expression.

The Use of microRNAs in the Management of Endometrial Cancer: A Meta-Analysis

Introduction: Endometrial cancer (EC) is the most important gynecological cancer in terms of incidence. microRNAs (miRs), which are post-transcriptional regulators implicated in a variety of cellular functions including carcinogenesis, are particularly attractive candidates as biomarkers. Indeed, several studies have shown that the miR expression pattern appears to be associated with prognostic factors in EC. Our objective is to review the current knowledge of the role of miRs in carcinogenesis and tumor progression and their association with the prognosis of endometrial cancer. Materials and Method: We performed a literature search for miR expression in EC using MEDLINE, PubMed (the Internet portal of the National Library of Medicine) and The Cochrane Library, Cochrane databases “Cochrane Reviews” and “Clinical Trials” using the following keywords: microRNA, endometrial cancer, prognosis, diagnosis, lymph node, survival, plasma, FFPE (formalin-fixed, paraffin-embedded). The miRs were classified and presented according to their expression levels in cancer tissue in relation to different prognostic factors. Results: Data were collected from 74 original articles and 8 literature reviews which described the expression levels of 261 miRs in ECs, including 133 onco-miRs, 110 miR onco-suppressors, and 18 miRs with discordant functions. The review identified 30 articles studying the expression pattern of miR in neoplastic endometrial tissue compared to benign and/or hyperplastic tissues, 12 articles detailing the expression profile of miRs as a function of lymph node status, and 14 articles that detailed the expression pattern of miRs in endometrial tumor tissue according to overall survival or in the absence of recurrence. Conclusions: The findings presented here suggest that miR analysis merits a role as a prognostic factor in the management of patients with endometrial cancer.

Cervical, Ovarian and Endometrial Tumor Markers: Potential Clinical Value

Tumors markers can be described as molecular products expressed by neoplasia tissues (immunohistochemistry), or metabolized and secreted by tumor and characterized biochemically in body fluids such as blood and urine. They may have utility as indicators of tumor stage and grade as well useful for monitoring responses to treatment and predicting recurrence, progression, development of metastases, or even patient survival. Unfortunately, in some cases they may have no identified clinical potential. Several investigations have been carried out, especially in the last decade, using biotechnological methods, in order to identify new potential tumor markers. By translating these findings into clinical use one may facilitate accurate diagnosis and prognostic prediction, and contribute to individualized treatment. The objective of this review is to describe some biomarkers with potential use in clinical settings of uterine cervix, ovary, and endometrium carcinomas.

Hypoxia-sensitive LINC01436 is regulated by E2F6 and acts as an oncogene by targeting miR-30a-3p in non-small cell lung cancer

Dysregulation of long noncoding RNA (lncRNA) is known to be involved in numerous human diseases, including lung cancer. However, the precise biological functions of most lncRNA remain to be elucidated. Here, we identified a novel up‐regulated lncRNA, LINC01436 (RefSeq: NR_110419.1), in non‐small cell lung cancer (NSCLC). High expression of LINC01436 was significantly associated with poor overall survival. Notably, LINC01436 expression was transcriptionally repressed by E2F6 under normoxia, and the inhibitory effect was relieved in a hypoxic microenvironment. Gain‐ and loss‐of‐function studies revealed that LINC01436 acted as a proto‐oncogene by promoting lung cancer cell growth, migration and invasion in vitro. Xenograft tumor assays in nude mice confirmed that LINC01436 promoted tumor growth and metastasis in vivo. Mechanistically, LINC01436 exerted biological functions by acting as a microRNA (miR)‐30a‐3p sponge to regulate the expression of its target gene EPAS1. Our findings characterize LINC01436 as a new hypoxia‐sensitive lncRNA with oncogenic function in NSCLC, suggesting that LINC01436 may be a potential biomarker for prognosis and a potential target for treatment.

MiR-21 regulates the ACAT1 gene in MCF-7 cells

AIMS

The purpose of the present study was to determine whether miR-21 regulates the human ACAT1 gene. We also assessed whether transfection of MCF-7 cells with miR-21 mimic/inhibitor leads to changes in ACAT1 mRNA/protein levels, cell proliferation rate, or apoptosis.

MAIN METHODS

Regulation of ACAT1 3'UTR by miR-21 was evaluated using a dual-luciferase reporter assay. The effect of miR-21 on mRNA/protein levels of ACAT1 and PTEN (confirmed as an important target of miR-21 for comparison) was measured by qPCR/western blot analysis and immunostaining. Proliferation rate was determined by cell counting. Percentage of cells undergoing late apoptosis was determined by staining with Hoechst 33342/propidium iodide.

KEY FINDINGS

Dual-luciferase reporter assay confirmed the regulation of ACAT1 3'UTR by miR-21. Furthermore, transfection of MCF-7 cells with miR-21 mimic decreased mRNA and protein levels of ACAT1 and PTEN genes. In contrast, miR-21 inhibition increased the mRNA and protein levels of both genes studied. Finally, we observed an increase in cell proliferation and decrease in the percentage of cells in late apoptosis in MCF-7 cells transfected with miR-21 mimic, whereas transfection with miR-21 inhibitor led to the opposite effect.

SIGNIFICANCE

Our data confirm the hypothesis that miR-21 regulates the human ACAT1 gene. As the expression of this microRNA is altered in many types of cancers, the discovery of novel targets for miR-21 is of particular interest for diagnosis and treatment.

Identification of micro-RNA expression profile related to recurrence in women with ESMO low-risk endometrial cancer

Background

Actual European pathological classification of early-stage endometrial cancer (EC) may show insufficient accuracy to precisely stratify recurrence risk, leading to potential over or under treatment. Micro-RNAs are post-transcriptional regulators involved in carcinogenic mechanisms, with some micro-RNA patterns of expression associated with EC characteristics and prognosis. We previously demonstrated that downregulation of micro-RNA-184 was associated with lymph node involvement in low-risk EC (LREC). The aim of this study was to evaluate whether micro-RNA signature in tumor tissues from LREC women can be correlated with the occurrence of recurrences.

Methods

MicroRNA expression was assessed by chip analysis and qRT-PCR in 7 formalin-fixed paraffin-embedded (FFPE) LREC primary tumors from women whose follow up showed recurrences (R+) and in 14 FFPE LREC primary tumors from women whose follow up did not show any recurrence (R−), matched for grade and age. Various statistical analyses, including enrichment analysis and a minimum p-value approach, were performed.

Results

The expression levels of micro-RNAs-184, -497-5p, and -196b-3p were significantly lower in R+ compared to R− women. Women with a micro-RNA-184 fold change < 0.083 were more likely to show recurrence (n = 6; 66%) compared to those with a micro-RNA-184 fold change > 0.083 (n = 1; 8%), p = 0.016. Women with a micro-RNA-196 fold change < 0.56 were more likely to show recurrence (n = 5; 100%) compared to those with a micro-RNA-196 fold change > 0.56 (n = 2; 13%), p = 0.001.

Conclusions

These findings confirm the great interest of micro-RNA-184 as a prognostic tool to improve the management of LREC women.

Diagnostic value of circulating miR-21: An update meta-analysis in various cancers and validation in endometrial cancer

MiR-21 has been identified as one of the most common proto-oncogenes. It is hypothesized that up-regulated miR-21 could be served as a potential biomarker for human cancer diagnosis. However, inconsistencies or discrepancies about diagnostic accuracy of circulating miR-21 still remain. In this sense, miR-21′s diagnostic value needs to be fully validated. In this study, we performed an update meta-analysis to estimate the diagnostic value of circulating miR-21 in various human cancers. Additionally, we conducted a validation test on 50 endometrial cancer patients, 50 benign lesion patients and 50 healthy controls. A systematical literature search for relevant articles was performed in Pubmed, Embase and Cochrane Library. A total of 48 studies from 39 articles, involving 3,568 cancer patients and 2,248 controls, were included in this meta-analysis. The overall sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR) and area under the curve (AUC) were 0.76 (0.71-0.80), 0.82 (0.79-0.85), 4.3 (3.6-5.1), 0.29 (0.24-0.35), 15 (11-20) and 0.86 (0.83-0.89), respectively. In the validation test, the expression levels of serum miR-21 were significantly higher in benign lesion patients (p = 0.003) and endometrial cancer patients (p = 0.000) compared with that of healthy controls. Endometrial cancer patients showed higher miR-21 expression levels (p = 0.000) compared with benign lesion patients. In conclusion, the meta-analysis shows that circulating miR-21 has excellent performance on the diagnosis for various cancers and the validation test demonstrates that serum miR-21 could be served as a novel biomarker for endometrial carcinoma.

Aberrant MicroRNA Expression in Patients With Endometrial Cancer

OBJECTIVE

Current evidence suggests that no single serum biomarker displays satisfactory diagnostic performance in patients with endometrial carcinoma (EC), the most frequent gynecological cancer in developed countries. However, aberrant tissue microRNA (miRNA) expression has been recently described in EC. Therefore, this study aimed to investigate the differential expression of 4 serum miRNAs and their association with CA125 (cancer antigen 125) and HE4 (human epididymis protein 4) in EC patients and in a control population.

METHODS

Forty-six consecutive women with EC and 28 matched control subjects without a history of cancer or other diseases were enrolled. Total serum RNA was extracted using mirVana PARIS Kit. TaqMan MicroRNA Assay was used for quantitative real-time reverse transcriptase-polymerase chain reaction on ABI 7500 Sequence Detection System to assess differential miRNAs expression. The relative expression levels of 4 miRNAs (miR-222, miR-223, miR-186, and miR-204) were normalized to miR-16 and calculated using the 2-△Ct approach.

RESULTS

Serum levels of miR-186, miR-222, and miR-223 appeared to be significantly higher in patients compared with control subjects (P = 0.004, P = 0.002, and P < 0.0001). Contrarily, serum miR-204 was found to be significantly lower in EC patients (P < 0.0001). The diagnostic performance of miRNAs was found to be significantly better than that of CA125. Among the various biomarker tested, serum miR-204 and HE4 exhibited the best diagnostic performance for discriminating EC patients from control subjects.

CONCLUSIONS

These results underpin that the 4 miRNAs that we have investigated are implicated in development and progression of EC, thus opening new avenues in EC diagnostics.

Reactivation of epigenetically silenced miR-124 reverses the epithelial-to-mesenchymal transition and inhibits invasion in endometrial cancer cells via the direct repression of IQGAP1 expression

Overexpression of IQGAP1 and microRNA (miRNA) dysregulation are frequent in human tumors, but little is known about the role of IQGAP1 and its relationship to miRNA in endometrial carcinogenesis. We demonstrate that IQGAP1 activates the epithelial–mesenchymal transition (EMT) program and that miR-124 directly represses IQGAP1 expression in endometrial cancer (EC) cells. The overexpression of IQGAP1 stimulates EMT features and enhances migration, invasion and proliferation of EC cells, whereas knocking down IQGAP1 expression reverses EMT and inhibits these malignant properties. Using miRNA microarray profiling, we identified 29 miRNAs (let-7b, let-7f, miR-10b, miR-15b, miR-23a, miR-24, miR-25, miR-27a, miR-29b, miR-30a-5p, miR-34a, miR-124, miR-127, miR-130b, miR-148a, miR-155, miR-191*, miR-194, miR-224, miR-362, miR-409-3p, miR-422b, miR-424, miR-453, miR-497, miR-518d, miR-518f*, miR-526a and miR-656) that are significantly down-regulated in an in vitro-selected highly invasive derivative cell line (HEC-50-HI) relative to the parental HEC-50 cells. We further identified miR-124 as a direct regulator of IQGAP1 in EC cells. Enforced expression of miR-124 suppresses EC cell invasion and proliferation. The expression of IQGAP1 mRNA was significantly elevated in EC tissues, while the expression of miR-124 was decreased. The downregulation of miR-124 correlates with a poor survival outcome for patients with EC. Treating EC cells with the demethylating agent 5-aza-2′-deoxycytidine increased miR-124 expression and down-regulated IQGAP1 levels. Our data suggest that IQGAP1 promotes EMT, migration and invasion of EC cells. MiR-124, a novel tumor suppressor miRNA that is epigenetically silenced in EC, can reverse EMT and the invasive properties, by attenuating the expression of the IQGAP1 oncogene.

miR-30a inhibits the biological function of breast cancer cells by targeting Notch1

miR-30a is situated on chromosome 6q.13 and is produced by an intronic transcriptional unit. However, its role in regulating the apoptosis, invasion and metastasis of breast cancer cells is not yet fully understood. The aim of this study was to research the biological function of miR‑30a and its direct target gene in breast cancer. The biological function of miR‑30a was determined by examining breast cancer cell growth, apoptosis, metastasis and invasion. In addition, Notch1 expression was measured by western blot analysis, and a luciferase reporter vector was constructed to identify the miR‑30a target gene. miR‑30a was found to be significantly downregulated in breast cancer cells. We also found that miR‑30a inhibited breast cancer cell viability, migration and invasion, and induced cell apoptosis. On the whole, our data indicate that miR‑30a attenuates the development of breast cancer by regulating the expression of the downstream target gene, Notch1.

Hypoxia- and acidosis-driven aberrations of secreted microRNAs in endometrial cancer in vitro

Due to their post-transcriptional regulatory impact on gene expression, microRNAs (miRNA, miRs) influence decisively cellular processes of differentiation, proliferation and apoptosis. In oncogenic pathways various miRNAs exert either oncogenic or tumor suppressor activities in a stage-specific manner. Dysregulation of miRNA expression pattern has been associated with several human cancers including endometrial cancer (EC). In the present study, expression profile alterations of EC associated secreted miRNAs were determined under the microenvironmental stress situations hypoxia and acidosis occurring in tumor progression and metastasis. The potential influence of hypoxia and acidosis vs. control conditions on the expression levels of 24 EC-relevant miRNA types was quantitatively accessed via real-time PCR in three established EC in vitro models. Expression data were analyzed statistically. In vitro application of hypoxia resulted in downregulation of miR-15a, miR-20a, miR-20b and miR-128-1 in Ishikawa cells (type I EC) and upregulation of miR-21 in EFE-184 cells (type I EC). Acidosis triggered upregulation of tumor promoting miR-125b in AN3-CA cell (type II EC), whereas in Ishikawa cells (type I EC) miRNAs with tumor suppressive function were found altered in divergent directions, both up- (let-7a) and down- (miR-22) regulated. Our current findings emphasize the functional importance of secreted miRNAs in the immediate response of EC cells to exogenic stress situations such as the typical tumor epiphenomena hypoxia and acidosis. Focusing on the specific potential of secreted, thus circulating miRNA molecules, alterations in expression levels not only influence intracellular gene expression and signaling cascades, but also transfer the induction of (tumor)biological cellular changes to adjacent cells.

Epigenetics in endometrial carcinogenesis - part 2: histone modifications, chromatin remodeling and noncoding RNAs

Carcinogenesis is a multistep multifactorial process that involves the accumulation of genetic and epigenetic alterations. In the past two decades, there has been an exponential growth of knowledge establishing the importance of epigenetic changes in cancer. Our work focused on reviewing the main role of epigenetics in the pathogenesis of endometrial carcinoma, highlighting the reported results concerning each epigenetic mechanistic layer. In a previous review, we assessed DNA methylation alterations. The present review examines the contribution of histone modifications, chromatin remodeling and noncoding RNA alterations for endometrial carcinogenesis.

Identification of Circulating MicroRNAs in Biliary Atresia by Next-Generation Sequencing

OBJECTIVES

Biliary atresia (BA) is an idiopathic neonatal liver disease, characterized by inflammatory and fibrotic obliteration of extrahepatic bile ducts. Therefore, reliable methods for noninvasive diagnosis are needed. The present study aimed to analyze circulating microRNAs (miRNAs) in patients with BA using next-generation sequencing for identifying novel diagnostic biomarkers.

METHODS

An initial screening of miRNAs in plasma from patients with BA and healthy controls (HCs) was performed on an Illumina next-generation sequencing platform. Differential miRNAs were validated by quantitative real-time polymerase chain reaction (qPCR). Target genes and related signal transduction pathways of differential miRNAs were predicted by online software.

RESULTS

In total, 146 differential miRNAs were identified by deep sequencing. Fifteen miRNAs with read counts >1000, that included 7 upregulated and 8 downregulated miRNAs, were predicted to be associated with liver fibrosis, biliary differentiation, and bile duct development. Of these, 6 miRNAs with read counts >5000 were analyzed by qPCR on an independent sample set comprising 44 patients with BA, 20 cholestatic disease controls, and 20 HCs. Two upregulated miRNAs (miR-122-5p, miR-100-5p) and 2 downregulated miRNAs (miR-140-3p, miR-126-3p) were confirmed by individual qPCR. Only miR-140-3p was significantly different from controls (P < 0.05), yielding an area under receiver operating characteristic curve of 0.75 with sensitivity of 66.7% and specificity of 79.1% at optimal threshold.

CONCLUSIONS

Our findings indicate that patients with BA exhibit a distinct profile of circulating miRNAs and that plasma miR-140-3p may be a promising diagnostic biomarker for this disease.

Prognostic and Clinical Significance of miRNA-205 in Endometrioid Endometrial Cancer

Endometrial cancer is one of the most common malignancies of the reproductive female tract, with endometrioid endometrial cancer being the most frequent type. Despite the relatively favourable prognosis in cases of endometrial cancer, there is a necessity to evaluate clinical and prognostic utility of new molecular markers. MiRNAs are small, non-coding RNA molecules that take part in RNA silencing and post-transcriptional regulation of gene expression. Altered expression of miRNAs may be associated with cancer initiation, progression and metastatic capabilities. MiRNA-205 seems to be one of the key regulators of gene expression in endometrial cancer. In this study, we investigated clinical and prognostic role of miRNA-205 in endometrioid endometrial cancer. After total RNA extraction from 100 archival formalin-fixed paraffin-embedded tissues, real-time quantitative RT-PCR was used to define miRNA-205 expression levels. The aim of the study was to evaluate miRNA-205 expression levels in regard to patients' clinical and histopathological features, such as: survival rate, recurrence rate, staging, myometrial invasion, grading and lymph nodes involvement. Higher levels of miRNA-205 expression were observed in tumours with less than half of myometrial invasion and non-advanced cancers. Kaplan-Maier analysis revealed that higher levels of miRNA-205 were associated with better overall survival (p = 0,034). These results indicate potential clinical utility of miRNA-205 as a prognostic marker.

miR-135b, a key regulator of malignancy, is linked to poor prognosis in human myxoid liposarcoma

Myxoid/round cell (RC) liposarcomas (MLS) were originally classified into two distinct populations based on histological differences; a myxoid component and a RC component. It is notable that, depending on an increase of the RC component, the prognosis significantly differs. Hence, the RC component is associated with metastasis and poor prognosis. However, the molecular mechanisms that contribute to the malignancy of the RC component still remain largely unknown. Here, we report microRNA-135b (miR-135b), a key regulator of the malignancy, highly expressed in the RC component and promoting MLS cell invasion in vitro and metastasis in vivo through the direct suppression of thrombospondin 2 (THBS2). Decreased THBS2 expression by miR-135b increases the total amount of matrix metalloproteinase 2 (MMP2) and influences cellular density and an extracellular matrix structure, thereby resulting in morphological change in tumor. The expression levels of miR-135b and THBS2 significantly correlated with a poor prognosis in MLS patients. Overall, our study reveals that the miR-135b/THBS2/MMP2 axis is tightly related to MLS pathophysiology and has an important clinical implication. This work provides noteworthy evidence for overcoming metastasis and improving patient outcomes, and sheds light on miR-135b and THBS2 as novel molecular targets for diagnosis and therapy in MLS.

MicroRNA-340 Inhibits Tumor Cell Proliferation and Induces Apoptosis in Endometrial Carcinoma Cell Line RL 95-2

BACKGROUND The purpose of our study was to investigate the functional role of microRNA-340 (miR-340) in endometrial carcinoma (EC). MATERIAL AND METHODS Human EC cell line RL 95-2 was transfected with miR-340 mimics, inhibitors, or controls. After 48 h of transfection, the cell viability was determined by 3-(4, 5-dimethyl-2- thiazolyl)-2, 5-diphenyl -2-H-tetrazolium bromide (MTT) assay. The BrdU assay and apoptosis assay were performed to determine the effects of miR-340 mimics or inhibitors on cell proliferation and apoptosis, respectively. The underlying mechanisms involved in cell proliferation and apoptosis were explored by measuring the protein levels of cell cycle regulators (p27 kinase inhibition protein (KIP) 1 and p21) and apoptosis-related factors (B-cell lymphoma-2 (Bcl-2), Bax, pro-Caspase 3, and active-Caspase-3). RESULTS Overexpression of miR-340 significantly inhibited the cell viability (P<0.05) and cell proliferation (P<0.01) of RL 95-2 cells compared with the control group, but increased the apoptosis (P<0.01). However, suppression of miR-340 had opposite results. Moreover, the protein levels of p27 KIP1, Bax, pro-Caspase 3, and active-Caspase-3 were significantly increased by overexpression of miR-340 but were statistically decreased by suppression of miR-340. Contrary results were found in the protein levels of Bcl-2. However, no significant differences were found in p21 expression. CONCLUSIONS MiRNA-340 acts as an anti-oncogene in EC cell line RL 95-2 by inhibition of tumor cell proliferation and induction of apoptosis.

Identification of microRNA expression profile related to lymph node status in women with early-stage grade 1-2 endometrial cancer

Conventional methods used for histologic classification and grading of endometrial cancer (EC) are not sufficient to predict lymph node metastases. microRNA signatures have recently been related to EC pathologic characteristics or prognosis. The aim of this study was to evaluate whether microRNA profiles of grade 1-2 endometrioid adenocarcinomas can be related to nodal status and used as a tool to adapt surgical staging in early-stage EC. microRNA expression was assessed in nine formalin-fixed paraffin-embedded (FFPE) EC primary tumors with positive lymph node and in 27 FFPE EC primary tumors with negative lymph node, matched for grade, stage, and lymphovascular space involvement status. A microarray analysis showed that there was more than a twofold significant difference in the expression of 12 microRNAs between the two groups. A quantitative reverse transcriptase-PCR assay was used to confirm these results: the expression levels of five microRNAs (microRNA-34c-5p, -375, -184, -34c-3p, and -34b-5p) were significantly lower in the EC primary tumor with positive lymph node compared with those with negative lymph node. A minimal P-value approach revealed that women with a microRNA-375-fold change <0.30 were more likely to have positive lymph node (n=8; 53.3%) compared with those with a microRNA-375-fold change >0.30 (n=1; 4.8%), P=0.001. Furthermore, women with a microRNA 184-fold change <0.30 were more likely to have positive lymph node (n=6; 60.0%) compared with those with a microRNA 184-fold change >0.30 (n=3; 11.5%), P=0.006. This is the first study investigating the relative expression of mature microRNA genes in early-stage grade 1-2 EC primary tumors according to the nodal status. This microRNA expression profile provides a potential basis for further study of the microRNA function in EC and could be used as a diagnostic tool for nodal status.

Small non-coding RNA deregulation in endometrial carcinogenesis

Small non-coding RNAs (sncRNAs) represent a heterogeneous group of <200nt-long transcripts comprising microRNAs, PIWI-interacting RNAs (piRNAs) and small-nucleolar-RNAs (snoRNAs) involved in physiological and pathological processes such as carcinogenesis and tumor progression. Aberrant sncRNA expression in cancer has been associated with specific clinical phenotypes, grading, staging, metastases development and resistance to therapy.Aim of the present work is to study the role of sncRNAs in endometrial carcinogenesis. Changes in sncRNA expression were identified by high-throughput genomic analysis of paired normal, hyperplastic and cancerous endometrial tissues obtained by endometrial biopsies (n = 10). Using smallRNA sequencing and microarrays we identified significant differences in sncRNA expression pattern between normal, hyperplastic and neoplastic endometrium. This led to the definition of a sncRNA signature (129 microRNAs, 2 of which not previously described, 10 piRNAs and 3 snoRNAs) of neoplastic transformation. Functional bioinformatics analysis identified as downstream targets multiple signaling pathways potentially involved in the hyperplastic and neoplastic tissue responses, including Wnt/β-catenin, and ERK/MAPK and TGF-β-Signaling.Considering the regulatory role of sncRNAs, this newly identified sncRNA signature is likely to reflect the events leading to endometrial cancer, which can be exploited to dissect the carcinogenic process including novel biomarkers for early and non-invasive diagnosis of these tumors.

Circulating Blood-Borne microRNAs as Biomarkers in Solid Tumors

One of the major challenges in cancer research is the identification of stable biomarkers that could be routinely measured in easily accessible samples. Human blood and other body fluids represent rich sources for the identification of novel biomarkers. It is apparent that the availability of these biomarkers would improve an early detection of asymptomatic disease and the clinical management of cancer. MicroRNAs have been described to be present in various types of body fluids including cell-free serum and plasma. These days, the involvement of microRNAs in molecular pathology of cancer is well established. Moreover, it seems that these molecules could be optimal noninvasive biomarkers owing to their high stability under storage and handling conditions and high sensitivity and specificity in various diseases. To date, more than 100 circulating microRNAs with the potential to serve as novel diagnostic, prognostic, or predictive biomarkers for different types of cancers have been identified, and this number is still increasing. However, there are major discrepancies in the findings by different research groups, and few commonly altered microRNAs have been reported in these studies. Further studies on large cohorts using uniform methodology are warranted to establish the clinical applicability of circulating microRNAs for solid tumors. Here, we summarize the tumor-specific profiles of blood-borne microRNAs and discuss their potential utility for personalized medicine of solid tumors.

The overexpression of miR-30a affects cell proliferation of chondrosarcoma via targeting Runx2

MicroRNAs (miRNAs) are emerging as important epigenetic modulators of multiple target genes, leading to abnormal cellular signaling involving cellular proliferation in cancers. Aberrant miRNA expression has been observed in human chondrosarcoma (CS). The purpose of the present study was to evaluate the expression and molecular mechanisms of Runx2 and miR-30a in human CS tissues and CS cell lines JJ012, SW1353, and L3252. In the present study, we found that the expression of miR-30a was markedly downregulated in CS cell lines and human CS tissues, compared to matched non-tumor-associated tissues. Furthermore, miR-30a expression was inversely proportional to that of Runx2 messenger RNA (mRNA) and protein. Upregulation of miR-30a dramatically reduced the proliferation, colony formation, and cell cycle-related proteins of CS cells. Flow cytometry analysis showed that ectopic expression of miR-30a significantly decreased the percentage of S phase cells and increased the percentage of G1/G0 phase cells. Luciferase reporter assays confirmed that miR-30a binding to the 3'-untranslated region (3'-UTR) region of Runx2 inhibited the expression of Runx2 in cancer cells. Taken together, our results suggest that miR-30a plays an important role to inhibit the proliferation of CS cells and presents a novel mechanism for direct miRNA-mediated suppression of Runx2 in CS. Thus, miR-30a/Runx2 may have an important role in treatment of CS patients.

Small RNA Sequencing Uncovers New miRNAs and moRNAs Differentially Expressed in Normal and Primary Myelofibrosis CD34+ Cells

Myeloproliferative neoplasms (MPN) are chronic myeloid cancers thought to arise at the level of CD34+ hematopoietic stem/progenitor cells. They include essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (PMF). All can progress to acute leukemia, but PMF carries the worst prognosis. Increasing evidences indicate that deregulation of microRNAs (miRNAs) might plays an important role in hematologic malignancies, including MPN. To attain deeper knowledge of short RNAs (sRNAs) expression pattern in CD34+ cells and of their possible role in mediating post-transcriptional regulation in PMF, we sequenced with Illumina HiSeq2000 technology CD34+ cells from healthy subjects and PMF patients. We detected the expression of 784 known miRNAs, with a prevalence of miRNA up-regulation in PMF samples, and discovered 34 new miRNAs and 99 new miRNA-offset RNAs (moRNAs), in CD34+ cells. Thirty-seven small RNAs were differentially expressed in PMF patients compared with healthy subjects, according to microRNA sequencing data. Five miRNAs (miR-10b-5p, miR-19b-3p, miR-29a-3p, miR-379-5p, and miR-543) were deregulated also in PMF granulocytes. Moreover, 3’-moR-128-2 resulted consistently downregulated in PMF according to RNA-seq and qRT-PCR data both in CD34+ cells and granulocytes. Target predictions of these validated small RNAs de-regulated in PMF and functional enrichment analyses highlighted many interesting pathways involved in tumor development and progression, such as signaling by FGFR and DAP12 and Oncogene Induced Senescence. As a whole, data obtained in this study deepened the knowledge of miRNAs and moRNAs altered expression in PMF CD34+ cells and allowed to identify and validate a specific small RNA profile that distinguishes PMF granulocytes from those of normal subjects. We thus provided new information regarding the possible role of miRNAs and, specifically, of new moRNAs in this disease.