The role of miRNAs in endometrial cancer

Differential expression of follicular fluid exosomal microRNA in women with diminished ovarian reserve

PURPOSE

Decreased ovarian reserve function is mainly characterized by female endocrine disorders and fertility decline. Follicular fluid (FF) exosomal microRNAs (miRNAs) have been shown to regulate the function of granulosa cells (GCs). The present study explored differentially expressed miRNAs (DEmiRNAs) in patients with diminished ovarian reserve (DOR).

METHODS

FF was collected from 12 DOR patients and 12 healthy controls. DEmiRNAs between the two groups were identified and analyzed using high-throughput sequencing technology and validated by real-time quantitative PCR (RT-qPCR).

RESULTS

A total of 592 DEmiRNAs were identified using high-throughput miRNA sequencing, of which 213 were significantly upregulated and 379 were significantly downregulated. The sequencing results were further validated by RT-qPCR. These DEmiRNA target genes were mainly involved in the cancer pathway, phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway, regulation of actin cytoskeleton signaling pathway, and biological processes related to protein binding, nucleoplasm, cytoplasm, and cell membrane.

CONCLUSION

FF exosomal miRNAs are significantly differentially expressed in DOR patients versus non-DOR patients, underscoring their crucial role in regulating the pathogenesis of DOR.

MicroRNA Expression in Endometrial Cancer: Current Knowledge and Therapeutic Implications

Background and Objectives: An extracellular vesicle is part of a class of submicron particles derived from cells, mediating cellular crosstalk through microRNA (miRNA). MiRNA is a group of RNA molecules, each of which consists of 15-22 nucleotides and post-transcriptionally modulates gene expression. The complementary mRNAs-onto which the miRNAs hybridize-are involved in processes such as implantation, tumor suppression, proliferation, angiogenesis, and metastasis that define the entire tumor microenvironment. The endometrial biopsy is a standard technique used to recognize cellular atypia, but other non-invasive markers may reduce patient discomfort during the use of invasive methods. The present study aims to examine the distribution and the regulation of the differentially expressed miRNAs (DEMs) and EV-derived substances in women with endometrial cancer. Materials and Methods: We systematically searched the PubMed, EMBASE, Scopus, Cochrane Library, and ScienceDirect databases in April 2023, adopted the string "Endometrial Neoplasms AND Exosomes", and followed the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We selected all the studies that included patients with endometrial cancer and that described the regulation of miRNA molecules in that context. The differences in molecule expression between patients and controls were evaluated as significant when the proteins had a fold change of ±1.5. Results: Seventeen records fulfilled the inclusion criteria: a total of 371 patients and 273 controls were analyzed. The upregulated molecules that had the widest delta between endometrial cancer patients and controls-relative expression ≥ 1 > 3 log2(ratio)-were miR-20b-5p, miR-204-5p, miR-15a-5p, and miR-320a. In particular, miR-20b-5p and miR-204-5p were extracted from both serum and endometrial specimens, whereas miR-15a-5p was only isolated from plasma, and miR-320a was only extracted from the endometrial specimens. In parallel, the most downregulated miRNA in the endometrial cancer patients compared to the healthy subjects was miR-320a, which was found in the endometrial specimens. Conclusions: Although their epigenetic regulation remains unknown, these upregulated molecules derived from EVs are feasible markers for the early detection of endometrial cancer. The modulation of these miRNA molecules should be assessed during different treatments or if recurrence develops in response to a targeted treatment modality.

Extracellular urinary microRNAs as non-invasive biomarkers of endometrial and ovarian cancer

INTRODUCTION

Gynecological cancers account for a large number of cancer-related deaths in women. Endometrial cancer is the most prevalent, while ovarian cancer is the deadliest gynecological cancer worldwide. To overcome the clinical need for easy and rapid testing, there is a growing interest in cancer detection in non-invasive modalities. With a growing field of liquid biopsy, urine became interesting source of cancer biomarkers.

OBJECTIVES

The aim of this manuscript is to provide an overview on the origin, analysis and the clinical significance of urine microRNAs in gynecological cancers, with a focus on ovarian and endometrial cancer. MicroRNAs, a class of small non-coding nucleic acids, are emerging as a non-invasive biomarkers due to the feasibility and the extreme stability in body fluids. Specific miRNA expression signatures have been previously identified in ovarian and endometrial cancer.

RESULTS

The aim of this manuscript is to provide an overview on the origin, analysis and the clinical significance of urine microRNAs in gynecological cancers, with the focus on ovarian and endometrial cancer.  CONCLUSION: The advantages and limitations of urine microRNA utility and technologies are discussed. Previously detected microRNA from urine of the patients are summarized to evaluate their potential as non-invasive clinical biomarkers in gynecological oncology.

DSCAM-AS1 Long Non-Coding RNA Exerts Oncogenic Functions in Endometrial Adenocarcinoma via Activation of a Tumor-Promoting Transcriptome Profile

Accumulating evidence suggests that lncRNA DSCAM-AS1 acts tumor-promoting in various cancer entities. In breast cancer, DSCAM-AS1 was shown to be the lncRNA being most responsive to induction by estrogen receptor α (ERα). In this study, we examined the function of DSCAM-AS1 in endometrial adenocarcinoma using in silico and different in vitro approaches. Initial analysis of open-source data revealed DSCAM-AS1 overexpression in endometrial cancer (EC) (p < 0.01) and a significant association with shorter overall survival of EC patients (HR = 1.78, p < 0.01). In EC, DSCAM-AS1 was associated with endometrial tumor promotor gene PRL and with expression of ERα and its target genes TFF1 and PGR. Silencing of this lncRNA by RNAi in two EC cell lines was more efficient in ERα-negative HEC-1B cells and reduced their growth and the expression of proliferation activators like NOTCH1, PTK2 and EGR1. DSCAM-AS1 knockdown triggered an anti-tumoral transcriptome response as revealed by Affymetrix microarray analysis, emerging from down-regulation of tumor-promoting genes and induction of tumor-suppressive networks. Finally, several genes regulated upon DSCAM-AS1 silencing in vitro were found to be inversely correlated with this lncRNA in EC tissues. This study clearly suggests an oncogenic function of DSCAM-AS1 in endometrial adenocarcinoma via activation of a tumor-promoting transcriptome profile.

Necroptosis-Related miRNA Biomarkers for Predicting Overall Survival Outcomes for Endometrial Cancer

Endometrial cancer (EC) is the gynecological tumor with the highest incidence. In recent years, it has been proved that necroptosis is a method of cell death related to EC. However, the expression of necroptosis-related miRNA in EC and its correlation with prognosis still ill-defined. Use the Cancer Genome Atlas (TCGA) cohort to obtain prognostic data and related clinical data for ECs and normal endometrium tissues. In this study, we identified three necroptotic regulatory miRNAs that are necroptosis-related and survival-related miRNAs (DENSMs) between normal endometrium tissues and EC from 13 necroptosis-related miRNAs. The three DENSMs signature was built to develop prognostic model and classified all EC patients into a high or low risk group. EC patients in the low-risk group showed significantly higher survival possibilities than those in the high-risk group (p = 0.0242), and the risk score was found to be an independent prognosis factor for predicting the OS of EC patients (p = 0.0254) in multivariate Cox regression. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed dephosphorylation, microtubule, protein serine/threonine kinase activity, PI3K-Akt signaling pathway and MAPK signaling pathway are closely related to it. In conclusion, the risk prediction model based on necroptosis-related miRNAs can effectively predict the prognosis of EC patients.

MicroRNAs in the Regulation of Endometrial Receptivity for Embryo Implantation

Development of endometrial receptivity is crucial for successful embryo implantation and pregnancy initiation. Understanding the molecular regulation underpinning endometrial transformation to a receptive state is key to improving implantation rates in fertility treatments such as IVF. With microRNAs (miRNAs) increasingly recognized as important gene regulators, recent studies have investigated the role of miRNAs in the endometrium. Studies on miRNAs in endometrial disorders such as endometriosis and endometrial cancer have been reviewed previously. In this minireview, we aim to provide an up-to-date knowledge of miRNAs in the regulation of endometrial receptivity. Since endometrial remodelling differs considerably between species, we firstly summarised the key events of the endometrial cycle in humans and mice and then reviewed the miRNAs identified so far in these two species with likely functional significance in receptivity establishment. To date, 29 miRNAs have been reported in humans and 15 miRNAs in mice within various compartments of the endometrium that may potentially modulate receptivity; miRNAs regulating the Wnt signalling and those from the let-7, miR-23, miR-30, miR-200 and miR-183 families are found in both species. Future studies are warranted to investigate miRNAs as biomarkers and/or therapeutic targets to detect/improve endometrial receptivity in human fertility treatment.

[WITHDRAWN] miR-144-3p Functions as a Tumor Suppressor in Endometrial Cancer by Targeting PRR11

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Circular RNA intraflagellar transport 80 facilitates endometrial cancer progression through modulating miR-545-3p/FAM98A signaling

Objective

Endometrial cancer (ECa) is a common gynecological malignancy. Circular RNAs (circRNAs) have been identified as key regulators of human tumorigenesis and development. Herein, we explored the role and mechanism of circular RNA intraflagellar transport 80 (circ-IFT80, also called circ_0067835) in ECa.

Methods

Circ-IFT80, microRNA-545-3p (miR-545-3p), and family with sequence similarity 98 member A (FAM98A) were quantified by quantitative real-time polymerase chain reaction or Western blot. The biological characteristics of ECa cells were evaluated via Cell Counting Kit-8, 5-ethynyl-2′-deoxyuridine, transwell, tube formation and flow cytometry assays. Dual-luciferase reporter assay or RNA pull-down assay was employed to verify the binding relationship between miR-545-3p and circ-IFT80 or FAM98A. Xenograft assays were conducted to analyze the effect of circ-IFT80 in vivo.

Results

Circ-IFT80 and FAM98A were up-regulated, and miR-545-3p was down-regulated in ECa tissues and cells. Knockdown of circ-IFT80 blocked proliferation, migration, invasion and angiogenesis and promoted apoptosis in ECa cells. Moreover, circ-IFT80 harbored a binding site for miR-545-3p, and the effects of circ-IFT80 were mediated by miR-545-3p. FAM98A was a direct target of miR-545-3p, and miR-545-3p hindered ECa cell progression via targeting FAM98A. Circ-IFT80 induced FAM98A expression through miR-545-3p. Furthermore, silence of circ-IFT80 suppressed tumor growth in vivo.

Conclusion

Circ-IFT80 may promote the malignant progression of ECa cells at least in part by modulating miR-545-3p/FAM98A axis, providing a potential therapeutic target for ECa.

We further investigated the potential role of circ-IFT80 in endometrial cancer (ECa) and unveiled that circ-IFT80 accelerated the malignant progression of ECa via decoying miR-545-3p and consequently enhancing FAM98A. Our findings provided novel insights into the pathogenesis of ECa and revealed promising therapeutic targets.

MiR-501 promotes tumor proliferation and metastasis by targeting HOXD10 in endometrial cancer

Background

Several studies have shown the crucial role of miR-501 in regulating cellular pathology in various cancers. However, the function and expression of miR-501 in endometrial cancer (EC) remain obscure.

Methods

The expression of miR-501 was determined using quantitative real-time PCR. MTT assay, colony formation assay and cell cycle analysis were used to evaluate the proliferation ability. Migration and invasion were assessed using transwell assay. Tumor formation in nude mice was used to observe the effects of miR-501 on cell proliferation and migration in vivo. Luciferase assay, quantitative real-time PCR and western blot were applied to determine that HOXD10 was the target gene of miR-501.

Results

In this study, we observed significantly up-regulated expression of miR-501 in endometrial cancer, which correlated with higher pelvic lymph node metastasis and shorter overall survival in high-grade endometrial cancer. High expression of miR-501 was also found in the copy-number-high group than other groups. Moreover, in vitro and in vivo assay showed that overexpression of miR-501 can promote proliferation and metastasis. Mechanistically, we found that miR-501 promotes tumor progression by directly targeting HOXD10. Further study also indicated that miR-501 overexpression can activate the AKT/mTOR pathway.

Conclusions

MiR-501, which functions as an oncomir in endometrial cancer, might be a potential therapeutic target in high grade endometrial cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-021-00268-7.

Circ_0109046 Promotes the Progression of Endometrial Cancer via Regulating miR-136/HMGA2 Axis

Background

Endometrial cancer (EC) is one of the most common gynecological malignancies. Circular RNAs (circRNAs) play crucial roles in the occurrence and development of tumors. This research aimed to explore the function and potential mechanism of human serum albumin (hsa)_circ_0109046 in EC.

Materials and Methods

The abundance of circ_0109046, microRNA-136 (miR-136) and high-mobility group AT-hook 2 (HMGA2) was detected by quantitative real-time polymerase chain reaction or Western blot. Cell counting kit-8 (CCK-8) and colony formation assays were employed to assess cell proliferation. Transwell assay was used to measure cell migration and invasion. The levels of E-cadherin, Vimentin and N-cadherin were examined by Western blot. The binding association among circ_0109046, miR-136 and HMGA2 was verified by dual-luciferase reporter assay, RNA pull-down assay and RNA immunoprecipitation assay. Xenograft assay was performed to test tumor growth in vivo.

Results

Circ_0109046 and HMGA2 were up-regulated, and miR-136 was down-regulated in EC tissues and cells. Knockdown of circ_0109046 impeded the proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) of EC cells. Moreover, miR-136 knockdown reversed the suppression of circ_0109046 silencing on EC development. HMGA2 overexpression abolished the inhibition of miR-136 on EC progression. Besides, depletion of circ_0109046 inhibited EC growth in vivo.

Conclusion

Circ_0109046 accelerated EC progression via modulating miR-136/HMGA2 axis, indicating that circ_0109046 might be a promising therapeutic target for EC.

Differential expression profile of plasma exosomal microRNAs in women with polycystic ovary syndrome

OBJECTIVE

To examine different expression profiles of plasma exosomal microRNA (miRNA) in polycystic ovary syndrome (PCOS) patients and controls, and their potential roles in PCOS pathogenesis.

DESIGN

Experimental study.

SETTING

Center for reproductive medicine.

PATIENT(S)

Seventy-five PCOS patients and 75 age-matched controls.

INTERVENTION(S)

Plasma exosomes miRNAs sequenced from 15 PCOS patients and 15 controls.

MAIN OUTCOME MEASURE(S)

Plasma exosomal miRNA expression and the correlation between PCOS phenotypes and miRNA expression.

RESULT(S)

The sequenced plasma exosomes miRNAs were further determined by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) in a larger cohort, followed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Correlation analysis and receiver operating characteristic (ROC) curve analysis were used to determine the association between PCOS phenotypes and miRNA expression. The miRNA sequencing revealed 34 exosomal miRNAs were differentially expressed between PCOS patients and controls. Via qRT-PCR, five differentially expressed miRNAs (miR-126-3p, miR-146a-5p, miR-20b-5p, miR-106a-5p, and miR-18a-3p) were identified. The GO and KEGG analyses predicted their target functions included axon guidance, mitogen-activated protein kinase (MAPK) signaling, endocytosis, circadian rhythms, and cancer pathways. The expression of these miRNAs correlated with menstrual cycle, antral follicle count, hormone level, and combined yielded a ROC curve area of 0.781 in discriminating PCOS patients from the controls.

CONCLUSION(S)

Differential expression of plasma exosomal miRNAs may confer a risk of PCOS and may be helpful in distinguishing PCOS patients from controls. Certain miRNA expression may associated to the disease progression, which could help in an epigenetic understanding of the pathophysiology of PCOS.

Insulin Resistance and Endometrial Cancer: Emerging Role for microRNA

Endometrial cancer (EC) remains one of the most common cancers of the female reproductive system. Epidemiological and clinical data implicate insulin resistance (IR) and its accompanying hyperinsulinemia as key factors in the development of EC. MicroRNAs (miRNAs) are short molecules of non-coding endogenous RNA that function as post-transcriptional regulators. Accumulating evidence has shown that the miRNA expression pattern is also likely to be associated with EC risk factors. The aim of this work was the verification of the relationships between IR, EC, and miRNA, and, as based on the literature data, elucidation of miRNA's potential utility for EC prevention in IR patients. The pathways affected in IR relate to the insulin receptors, insulin-like growth factors and their receptors, insulin-like growth factor binding proteins, sex hormone-binding globulin, and estrogens. Herein, we present and discuss arguments for miRNAs as a plausible molecular link between IR and EC development. Specifically, our careful literature search indicated that dysregulation of at least 13 miRNAs has been ascribed to both conditions. We conclude that there is a reasonable possibility for miRNAs to become a predictive factor of future EC in IR patients.

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.

Novel miRNA markers for the diagnosis and prognosis of endometrial cancer

As endometrial cancer (EC) is a major threat to female health worldwide, the ability to provide an accurate diagnosis and prognosis of EC is promising to improve its treatment guidance. Since the discovery of miRNAs, it has been realized that miRNAs are associated with every cell function, including malignant transformation and metastasis. This study aimed to explore diagnostic and prognostic miRNA markers of EC. In this study, differential analysis and machine learning were performed, followed by correlation analysis of miRNA-mRNA based on the miRNA and mRNA expression data. Nine miRNAs were identified as diagnostic markers, and a diagnostic classifier was established to distinguish between EC and normal endometrium tissue with overall correct rates >95%. Five specific prognostic miRNA markers were selected to construct a prognostic model, which was confirmed more effective in identifying EC patients at high risk of mortality compared with the FIGO staging system. This study demonstrates that the expression patterns of miRNAs may hold promise for becoming diagnostic and prognostic biomarkers and novel therapeutic targets for EC.

Long non-coding RNA CCAT1 is overexpressed in endometrial cancer and regulates growth and transcriptome of endometrial adenocarcinoma cells

BACKGROUND

Long non-coding RNAs (lncRNAs) play important roles in regulation of gene expression and are involved in pathogenesis of different diseases including cancer. Recent studies suggested the lncRNA Colon cancer associated transcript-1 (CCAT1) to act as putative oncogene. In this study, to elucidate the role of this lncRNA in endometrial cancer, we examined its expression in normal endometrium and type 1 endometrial cancer and knocked down its expression in endometrial cancer cell lines followed by transcriptome and pathway analyses.

METHODS

CCAT1 expression was examined in 100 tissue samples of normal endometrium and type 1 endometrial cancer tissues by means of RT-qPCR. Knockdown of CCAT1 expression in HEC-1B and RL95/2 endometrial cancer cells was performed by siRNA transfection. Affymetrix GeneChip arrays were used to elucidate the effect of both lncRNAs on the transcriptome of these cell lines.

RESULTS

Median CCAT1 expression was found to be 9.3-fold higher in endometrial cancer when compared to normal endometrium (p < 0.05). In contrast to premenopausal endometrium and G1, G2 and G3 graded endometrial cancer, CCAT1 expression was nearly absent in postmenopausal tissue. Knockdown of CCAT1 by transient siRNA transfection significantly reduced proliferation of HEC-1B cancer cells in vitro by 35.5 % 6 days after transfection and notably reduced their colony formation ability. Affymetrix microarray and Ingenuity pathway analyses revealed a set of up- or down-regulated genes in transfected ERα-negative HEC-1B cells forming a network controlled by the key regulators TNF and TP53, including genes known to be involved in growth control, providing putative molecular mechanisms underlying the observed growth inhibition of HEC-1B cells. In contrast, CCAT1 knockdown in ERα-positive RL95/2 cells did not significantly affect proliferation, but resulted in down-regulation of a network of ERα target genes.

CONCLUSIONS

Given that the lncRNA CCAT1 was found to be overexpressed in endometrial cancer, affected the growth of HEC-1B cells and the expression of growth regulatory genes, our data suggest CCAT1 to exert oncogenic functions in endometrial cancer and encourage further studies to examine to what extent this lncRNA might be a potential therapy target in this cancer entity.

MicroRNA-135a promotes proliferation, migration, invasion and induces chemoresistance of endometrial cancer cells

Aims

MicroRNAs play essential roles in tumorigenesis and progression in various cancers including endometrial cancer. Here we assessed the role of miR-135a on proliferation, chemosensitivity, migration and invasion of endometrial cancer cells.

Methods

WST-1 assay was performed to examine the proliferation of HEC-1-B and ISHIKAWA endometrial cancer cells with altered expression of miR-135a, with or without cisplatin treatment. Transwell migration and matrigel invasion assays were used to assess the migration and invasion of endometrial cancer cells. The Caspase-Glo3/7 assay was used to examine the effect of miR-135a on cisplatin-induced apoptosis of endometrial cancer cells. The dual-luciferase reporter assay was conducted to validate the putative binding site.

Results

Upregulation of miR-135a improved the proliferation, and promoted migration and invasion of endometrial cancer cells. Furthermore, miR-135a decreased the sensitivity of HEC-1-B and ISHIKAWA cells after cisplatin treatment. The cisplatin-induced apoptosis in endometrial cancer cells was inhibited by miR-135a by regulation of BAX and Bcl-2 expression. Meanwhile, miR-135a could regulate epithelial to mesenchymal transition (EMT) by altering the expression of E-cadherin, N-cadherin, snail and Vimentin in endometrial cancer cells. Further study showed that the expression levels of PTEN and p-AKT in endometrial cancer cells were changed after aberrant expression of miR-135a.

Conclusion

MiR-135a played important roles in tumorigenesis and disease progression of endometrial cancer by regulating proliferation and chemosensitivy of endometrial cancer cells by targeting AKT signaling pathway. Our study indicates that miR-135a might act as a potential biomarker to predict chemotherapy response and prognosis in endometrial cancer.

Reproductive Cancer Risk Factors in Women With Myotonic Dystrophy (DM): Survey Data From the US and UK DM Registries

Introduction: Recent evidence demonstrates that women with myotonic dystrophy type 1 are at increased risk of reproductive organ tumors. However, studies of reproductive cancer risk factors in those patients are lacking.

Methods: Using questionnaires, we collected and analyzed personal history information related to cancer risk factors from women enrolled in a UK and US registry for myotonic dystrophy (dystrophia myotonica; DM) patients.

Results: The survey was completed by 242 DM type 1 (DM1) and 44 DM type 2 (DM2) women enrolled in the UK Registry (N = 124) and the US National Registry (N = 162). The mean age at DM1 diagnosis was 33.8 years (standard deviation, SD = 13.2) and for DM2 was 49.2 (SD = 13.0). Mean age at survey was 48.7 (SD = 12.8) and 59.1 years (SD = 12.8) for DM1 and DM2, respectively. There were no statistically significant differences between DM1 and DM2 regarding menstrual history or fertility-related factors. Yet, women with DM2 were more likely to have used menopausal hormone therapy (HT) than women with DM1 (52.3 vs. 22.1%, p < 0.0001), and more women with DM2 had a hysterectomy (53.5 vs. 29.5%, p < 0.01). These differences were not statistically significant after age adjustment (OR = 2.00, p = 0.08, and OR = 1.40, p = 0.38, respectively). The frequency of self-reported reproductive organ tumors was not significantly different comparing DM1 to DM2 (p = 0.28). However, the data suggested that women with DM2 appear to have a lower risk of malignant tumors compared to those with DM1 (OR = 0.72, p = 0.69).

Discussion: Our study is the first to characterize a wide range of reproductive risk factors in women with DM. We observed no significant differences between DM1 and DM2 in the factors that were evaluated, which suggests that the known excesses of ovarian and endometrial cancer previously reported in women with DM1 cannot be attributed to greater prevalence of standard cancer-related reproductive risk factors. Larger studies evaluating the possible link between reproductive cancer risk factors and risk of tumors in women with DM are needed.

EV-Associated miRNAs from Peritoneal Lavage are a Source of Biomarkers in Endometrial Cancer

Endometrial cancer (EC) is the sixth most common cancer in women worldwide and is responsible for more than 89,000 deaths every year. Mortality is associated with presence of poor prognostic factors at diagnosis, i.e., diagnosis at an advanced stage, with a high grade and/or an aggressive histology. Development of novel approaches that would permit us to improve the clinical management of EC patients is an unmet need. In this study, we investigate a novel approach to identify highly sensitive and specific biomarkers of EC using extracellular vesicles (EVs) isolated from the peritoneal lavage of EC patients. EVs of peritoneal lavages of 25 EC patients were isolated and their miRNA content was compared with miRNAs of EVs isolated from the ascitic fluid of 25 control patients. Expression of the EV-associated miRNAs was measured using the Taqman OpenArray technology that allowed us to detect 371 miRNAs. The analysis showed that 114 miRNAs were significantly dysregulated in EC patients, among which eight miRNAs, miRNA-383-5p, miRNA-10b-5p, miRNA-34c-3p, miRNA-449b-5p, miRNA-34c-5p, miRNA-200b-3p, miRNA-2110, and miRNA-34b-3p, demonstrated a classification performance at area under the receiver operating characteristic curve (AUC) values above 0.9. This finding opens an avenue for the use of EV-associated miRNAs of peritoneal lavages as an untapped source of biomarkers for EC.

Long Noncoding RNA-ATB Impairs the Function of Tumor Suppressor miR-126-Mediated Signals in Endometrial Cancer for Tumor Growth and Metastasis

OBJECTIVE

Long non-coding RNA-ATB (Lnc-ATB) have been reported to promote tumor proliferation and metastasis via regulation of tumor suppressive miRNA-related signals. Patients with endometrial cancer (EC) have advanced stage disease or metastasis have poor prognosis. We here investigated the role of Lnc-ATB in endometrial cancer.

METHODS

Endometrial cancer tissues and normal tissues (n = 35) were collected to determine the expression and clinical significance of Lnc-ATB, and bioinformatics analysis was used to predict the miRNA target. siRNA was used to estimate the function of Lnc-ATB in EC cell lines and in vivo.

RESULT

The expression of Lnc-ATB is up-regulated in tumor tissues and EC cell lines. Patients with high expressed Lnc-ATB have high FIGO stage and poor tumor differentiation. The tumor suppressor miR-126 interacted with Lnc-ATB. Down-regulated miR-126 negative correlated with FIGO stage and tumor differentiation. Knockdown of Lnc-ATB in RL95 and HEC1A cell lines increased the miR-126 level and impaired the cell vitality, induced caspase-3-related tumor apoptosis and G1/S arrest. However, abrogation of miR-126 by its inhibitors counteracted Lnc-ATB knockdown-induced tumor inhibition via regulation of miR-126 target gene PIK3R2 and Sox2-related apoptosis and cell cycle pathway. Meanwhile, Lnc-ATB knockdown also suppressed the migration and invasion and inhibited TGF-β-induced epithelial-mesenchymal transition (EMT) phenotype via miR-126. Knockdown of Lnc-ATB in vivo remarkably induced tumor regression via restoration of tumor suppressor miR-126, leading to deceased tumor volume, reduced expression of PCNA and PIK3R2/Sox2 signals and EMT phenotype in tumor tissues.

CONCLUSION

These data demonstrate the tumorigenic role of Lnc-ATBs in endometrial cancer via abrogation of tumor suppressor miR-126 signals.

miR-152 inhibits proliferation of human endometrial cancer cells via inducing G2/M phase arrest by suppressing CDC25B expression

microRNA-152 (miR-152) is a tumor suppressor that is down-regulated in many cancers including endometrial cancer (EC). However, the underlying mechanism of action of miR-152 in EC is unclear. The aim of the present study was to evaluate the role of miR-152 on proliferation of human endometrial cancer cells. Herein, we found that miR-152 overexpression and CDC25B knockdown inhibited proliferative ability and induced G2/M phase arrest in KLE and HEC-1B cells. CDC25B was a target of miR-152. In addition, CDC25B overexpression rescued miR-152-induced proliferation inhibition and G2/M phase arrest in human endometrial cancer cells. The results indicated that miR-152 was a tumor suppressor in EC that inhibited proliferation of human endometrial cancer cells via inducing G2/M phase arrest by suppressing CDC25B expression.

Non-Coding RNAs in Endometrial Physiopathology

The Human Genome Project led to the discovery that about 80% of our DNA is transcribed in RNA molecules. Only 2% of the human genome is translated into proteins, the rest mostly produces molecules called non-coding RNAs, which are a heterogeneous class of RNAs involved in different steps of gene regulation. They have been classified, according to their length, into small non-coding RNAs and long non-coding RNAs, or to their function, into housekeeping non-coding RNAs and regulatory non-coding RNAs. Their involvement has been widely demonstrated in all cellular processes, as well as their dysregulation in human pathologies. In this review, we discuss the function of non-coding RNAs in endometrial physiology, analysing their involvement in embryo implantation. Moreover, we explore their role in endometrial pathologies such as endometrial cancer, endometriosis and chronic endometritis.