Prognostic significance of miR-205 in endometrial cancer

MiR-205-5p and MiR-222-3p as Potential Biomarkers of Endometrial Cancer

Endometrial cancer is the fourth most common cancer in women in Europe. Its carcinogenesis is a complex process and requires further research. In our study, we focus on finding new and easy-to-diagnose markers for detecting endometrial cancer. For this purpose, we compared the levels of miR-21-5p, miR-205-5p, and miR-222-3p in endometrial cancer tissues with the levels of these miRs in the serum of patients using the dPCR method. Our study is preliminary and consists of comparing the changes in miRNA expression in serum to the changes in miRNA in tissue of patients with endometrial cancer. The study included 18 patients with EC and 19 patients undergoing surgery for pelvic organ prolapse or uterine fibroids as a control group without neoplastic lesions. Endometrial tissue and serum were collected from all patients. The analyses showed an increased expression of miR-205-5p in endometrial cancer tissue and decreased expression of miR-222-3p in tissue and serum samples. These results suggest that miR-205-5p and miR-222-3p may be potential endometrial cancer biomarkers. Only miR-222-3p confirmed its decreased expression in serum, making it a potential and easily accessible marker in the diagnosis of endometrial cancer. This pilot study requires further investigation in a larger group of patients. Its advantages include the possibility of a comparison between miRNA expression in tissue and serum, as well as conducting the study using dPCR.

microRNA profile of endometrial cancer from Indian patients-identification of potential biomarkers for prognosis

Endometrial cancer is one of the major cancers in women throughout the world. If diagnosed early, these cancers are treatable and the prognosis is usually good. However, one major problem in treating endometrial cancer is accurate diagnosis and staging. Till date, the choice method for diagnosis and staging is histopathology. Although there are few molecular markers identified, they are not always sufficient in making accurate diagnosis and deciding on therapeutic strategy. As a result, very often patients are under treated or over treated. In this study, our group has profiled microRNAs from Indian patients using NGS-based approach. We have identified 212 differentially expressed microRNAs in endometrial cancer. Among these, there are 17 novel miRNAs. Since this data represents only Indian cohort and also lacks survival data, validation across other populations is necessary before being considered as biomarkers. As one approach towards this, these microRNAs have also been compared to data from TCGA, which represent other populations and also correlated to relevance in overall survival. Using in-silico approaches, mRNA targets of the miRNAs have been predicted. After comparing with TCGA, we have identified 16 miRNA-mRNA pairs which could be potential prognostic biomarkers for endometrial cancer. This is the first miRNA profiling report from Indian cohort and one of the very few studies which have identified potential biomarkers of prognosis in endometrial cancer.

MicroRNA Landscape in Endometrial Carcinomas in an Asian population: Unraveling Subtype-Specific Signatures

MicroRNAs (MiRNAs) are small, non-coding RNA molecules that function in RNA silencing and post-transcriptional regulation of gene expression. We analyzed the differential expression of miRNAs in 119 endometrial carcinomas, measuring their expression in histological subtypes, molecular subtypes, and tumors with CTNNB1 mutations. Tumors were subdivided into histological and molecular subtypes as defined by The Cancer Genome Atlas. The expression levels of 352 miRNAs were quantified using the PanoramiR panel. Mir-449a, mir-449b-5p, and mir-449c-5p were the top three miRNAs showing increased expression in both endometrioid and de-differentiated carcinomas but were not significantly increased in serous and clear cell carcinomas. The miRNAs with the most increased expression in serous and clear cell carcinomas were miR-9-3p and miR-375, respectively. We also identified 62 differentially expressed miRNAs among different molecular subtypes. Using sequential forward selection, we built subtype classification models for some molecular subtypes of endometrial carcinoma, comprising 5 miRNAs for MMR-deficient tumors, 10 miRNAs for p53-mutated tumors, and 3 miRNAs for CTNNB1-mutated tumors, with areas under curves of 0.75, 0.85, and 0.78, respectively. Our findings confirm the differential expression of miRNAs between various endometrial carcinoma subtypes and may have implications for the development of diagnostic and prognostic tools.

The Role of miRNAs in the Development, Proliferation, and Progression of Endometrial Cancer

Endometrial cancer is one of the most common cancers in developing and developed countries. Although the detection of this cancer is high at the early stages, there is still a lack of markers to monitor the disease, its recurrence, and metastasis. MiRNAs are in charge of the post-transcriptional regulation of genes responsible for the most important biological processes, which is why they are increasingly used as biomarkers in many types of cancer. Many studies have demonstrated the influence of miRNAs on the processes related to carcinogenesis. The characteristics of miRNA expression profiles in endometrial cancer will allow their use as diagnostic and prognostic biomarkers. This paper focuses on the discussion of selected miRNAs based on the literature and their role in the development of endometrial cancer.

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.

The Role of MicroRNAs in Development of Endometrial Cancer: A Literature Review

Endometrial cancer (EC) ranks as the second most common gynaecological cancer worldwide. EC patients are diagnosed at an early clinical stage and generally have a good prognosis. Therefore, there is a dire need for development of a specific marker for early detection of endometrial adenocarcinoma. The development of EC is conditioned by a multistep process of oncogenic upregulation and tumor suppressor downregulation as shown by molecular genetic evidence. In this setting, microRNAs appear as significant regulators of gene expression and several variations in the expression of microRNAs have been implicated in normal endometrium, endometrial tissue, metrorrhagia, and endometrial cancer. Furthermore, microRNAs act as highly precise, sensitive, and robust molecules, making them potential markers for diagnosing specific cancers and their progression. With the rising incidence of EC, its management remains a vexing challenge and diagnostic methods for the disease are limited to invasive, expensive, and inaccurate tools. Therefore, the prospect of exploiting the utility of microRNAs as potential candidates for diagnosis and therapeutic use in EC seems promising.

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.

microRNA-205 in prostate cancer: Overview to clinical translation

Prostate cancer (PrCa) is the most common type of cancer among men in the United States. The metastatic and advanced PrCa develops drug resistance to current regimens which accounts for the poor management. microRNAs (miRNAs) have been well-documented for their diagnostic, prognostic, and therapeutic roles in various human cancers. Recent literature confirmed that microRNA-205 (miR-205) has been established as one of the tumor suppressors in PrCa. miR-205 regulates number of cellular functions, such as proliferation, invasion, migration/metastasis, and apoptosis. It is also evident that miR-205 can serve as a key biomarker in diagnostic, prognostic, and therapy of PrCa. Therefore, in this review, we will provide an overview of tumor suppressive role of miR-205 in PrCa. This work also outlines miR-205's specific role in targeted mechanisms for chemosensitization and radiosensitization in PrCa. A facile approach of delivery paths for successful clinical translation is documented. Together, all these studies provide a novel insight of miR-205 as an adjuvant agent for reducing the widening gaps in clinical outcome of PrCa patients.

Dual function miR-205 is positively associated with ER and negatively with five-year survival in breast cancer patients

BACKGROUND

Precise molecular characterization of breast cancer, especially triple negative (TNBC) as the most lethal subtype, is needed to stratify patients for the individual treatment approach. MicroRNA-205 (miR-205) has tumor-suppressive and oncogenic functions across different cancers. Therefore, miR-205 might have a different role in TNBC and estrogen receptor (ER) positive BC. Our aim was to investigate how miR-205 expression is associated with ER/progesteron receptor status, clinical parameters, pathohistological characteristics of BC, and survival of patients METHODS: We determined miR-205 relative expressions in 73 primary breast tumors (50 TNBC and 23 ER+) by quantitative Real-time polymerase chain reaction (qPCR) and compared it to clinicopathological characteristics and outcome.

RESULTS

The highest levels of miR-205 were in the ER+ /PR+ group, and the lowest in the TNBC group (p = 0.009). Significantly higher levels of miR-205 were also observed in the ER+ compared with the ER-negative group, regardless of the PR status (p = 0.002). Low miR-205 expression level was associated with prognostic stage III in TNBC samples (p = 0.049). Patients who received adjuvant chemotherapy had significantly lower levels of miR-205 (p = 0.016). Patients who received hormone therapy had significantly higher levels of miR-205 (p = 0.007). The low-miR-205 patients had significantly higher 5-year survival rates (p = 0.041).

CONCLUSION

The expression of miR-205 in BC is subtype-specific and high expression is associated with the ER+ tumors. The miR-205 expression might be a useful marker of TNBC progression. High miR-205 expression had a detrimental effect on BC patient outcome. Our results indicate that miR-205 might be utilized in clinical practice as a biomarker and an adjunct parameter for the selection of the most effective therapeutic modality.

Endometrial Cancer-Adjacent Tissues Express Higher Levels of Cancer-Promoting Genes than the Matched Tumors

Molecular alterations in tumor-adjacent tissues have recently been recognized in some types of cancer. This phenomenon has not been studied in endometrial cancer. We aimed to analyze the expression of genes associated with cancer progression and metabolism in primary endometrial cancer samples and the matched tumor-adjacent tissues and in the samples of endometria from cancer-free patients with uterine leiomyomas. Paired samples of tumor-adjacent tissues and primary tumors from 49 patients with endometrial cancer (EC), samples of endometrium from 25 patients with leiomyomas of the uterus, and 4 endometrial cancer cell lines were examined by the RT-qPCR, for MYC, NR5A2, CXCR2, HMGA2, LIN28A, OCT4A, OCT4B, OCT4B1, TWIST1, STK11, SNAI1, and miR-205-5p expression. The expression levels of MYC, NR5A2, SNAI1, TWIST1, and STK11 were significantly higher in tumor-adjacent tissues than in the matched EC samples, and this difference was not influenced by the content of cancer cells in cancer-adjacent tissues. The expression of MYC, NR5A2, and SNAI1 was also higher in EC-adjacent tissues than in samples from cancer-free patients. In addition, the expression of MYC and CXCR2 in the tumor related to non-endometrioid adenocarcinoma and reduced the risk of recurrence, respectively, and higher NR5A2 expression in tumor-adjacent tissue increased the risk of death. In conclusion, tissues proximal to EC present higher levels of some cancer-promoting genes than the matched tumors. Malignant tumor-adjacent tissues carry a diagnostic potential and emerge as new promising target of anticancer therapy.

Recommendations for extracellular vesicle miRNA biomarker research in the endometrial cancer context

Endometrial cancer (EC) is the most common gynaecological malignancy in the developed world, and concerningly incidence is rising, particularly in younger people. Therefore, there is increased interest in novel diagnostic and prognostic biomarkers. Extracellular vesicles (EVs) are membrane-bound particles present in bodily fluids that have the potential to facilitate non-invasive, early diagnosis of EC and could aid with monitoring of recurrence and treatment response. EV cargo provides molecular insight into the tumor, with the lipid bilayer providing stability for RNA species usually prone to degradation. miRNAs have recently become a focus for EV biomarker research due to their ability to regulate cancer related pathways and influence cancer development and progression. This review evaluates the current literature on EV miRNA biomarkers with a focus on EC, and discusses the challenges facing this research. This review finally highlights areas of focus for EV miRNA biomarker research going forward, such as standardization of normalization approaches, sample storage and processing, extensive reporting of methodologies and moving away from single miRNA biomarkers.

LncAABR07025387.1 Enhances Myocardial Ischemia/Reperfusion Injury Via miR-205/ACSL4-Mediated Ferroptosis

Ferroptosis is associated with the pathology of myocardial ischemia/reperfusion (MI/R) injury following myocardial infarction, which is a leading cause of death worldwide. Although long noncoding RNAs (lncRNAs) are known to regulate gene expression, their roles in MI/R-induced ferroptosis remain unclear. In this study, we explored the lncRNA expression profiles in a rat model of MI/R injury and found that the novel lncRNA, lncAABR07025387.1, was highly expressed in MI/R-injured myocardial tissues and hypoxia/reoxygenation (H/R)-challenged myocardial cells. Silencing lncAABR07025387.1 improved MI/R injury in vivo and inhibited myocardial cell ferroptosis under H/R conditions. Bioinformatics analyses and luciferase, pull-down, and RNA-binding immunoprecipitation assays further revealed that lncAABR07025387.1 interacted with miR-205, which directly targeted ACSL4, a known contributor to ferroptosis. Furthermore, downregulating miR-205 reversed the ACSL4 inhibition induced by silencing lncAABR07025387.1. These findings suggest that, mechanistically, lncAABR07025387.1 negatively regulates miR-205 expression and subsequently upregulates ACSL4-mediated ferroptosis. In conclusion, this study demonstrates that lncAABR07025387.1 acts as a competing endogenous RNA during MI/R injury and highlights the therapeutic potential of lncRNAs for treating myocardial injury.

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.

Small Non-Coding-RNA in Gynecological Malignancies

Gynecologic malignancies, which include cancers of the cervix, ovary, uterus, vulva, vagina, and fallopian tube, are among the leading causes of female mortality worldwide, with the most prevalent being endometrial, ovarian, and cervical cancer. Gynecologic malignancies are complex, heterogeneous diseases, and despite extensive research efforts, the molecular mechanisms underlying their development and pathology remain largely unclear. Currently, mechanistic and therapeutic research in cancer is largely focused on protein targets that are encoded by about 1% of the human genome. Our current understanding of 99% of the genome, which includes noncoding RNA, is limited. The discovery of tens of thousands of noncoding RNAs (ncRNAs), possessing either structural or regulatory functions, has fundamentally altered our understanding of genetics, physiology, pathophysiology, and disease treatment as they relate to gynecologic malignancies. In recent years, it has become clear that ncRNAs are relatively stable, and can serve as biomarkers for cancer diagnosis and prognosis, as well as guide therapy choices. Here we discuss the role of small non-coding RNAs, i.e., microRNAs (miRs), P-Element induced wimpy testis interacting (PIWI) RNAs (piRNAs), and tRNA-derived small RNAs in gynecological malignancies, specifically focusing on ovarian, endometrial, and cervical cancer.

Long non-coding RNA RP11-379k17.4 derived microRNA-200c-3p modulates human endometrial cancer by targeting Noxa

Objective: The research paid close attention to the function of lncRNA-related endogenous competitive RNAs (ceRNAs) network in endometrial cancer (EC).

Methods: 45 primary endometrial cancer tissues (EC) and 45 normal endometrium (NE) were included in the research. The online software StarbaseV2.0 was made use of forecasting the lncRNA which most likely contained microRNA-200c-3p combining sites and could interact with microRNA-200c-3p. Subsequently, we chose lncRNAs which were consistent with the characteristics of polyadenylation of lncRNAs and lower expression in EC than that of NE. After that, lncRNAs, which were related with the microRNA-200c-3p-noxa network, were identified.

Results: Rp11-379k17.4, a new gene related to endometrial cancer, was identified as noncoding RNA. It was a more effective ceRNA associated with the microRNA-200c-3p-noxa network.

Conclusion: LncRNAs possess microRNA response elements (MREs) and give scope to significant roles in the post-transcriptional mechanism in EC.

Flavonoid display ability to target microRNAs in cancer pathogenesis

MicroRNAs (miRNAs) are non-coding, conserved, single-stranded nucleotide sequences involved in physiological and developmental processes. Recent evidence suggests an association between miRNAs' deregulation with initiation, promotion, progression, and drug resistance in cancer cells. Besides, miRNAs are known to regulate the epithelial-mesenchymal transition, angiogenesis, autophagy, and senescence in different cancer types. Previous reports proposed that apart from the antioxidant potential, flavonoids play an essential role in miRNAs modulation associated with changes in cancer-related proteins, tumor suppressor genes, and oncogenes. Thus, flavonoids can suppress proliferation, help in the development of drug sensitivity, suppress metastasis and angiogenesis by modulating miRNAs expression. In the present review, we summarize the role of miRNAs in cancer, drug resistance, and the chemopreventive potential of flavonoids mediated by miRNAs. The potential of flavonoids to modulate miRNAs expression in different cancer types demonstrate their selectivity and importance as regulators of carcinogenesis. Flavonoids as chemopreventive agents targeting miRNAs are extensively studied in vitro, in vivo, and pre-clinical studies, but their efficiency in targeting miRNAs in clinical studies is less investigated. The evidence presented in this review highlights the potential of flavonoids in cancer prevention/treatment by regulating miRNAs, although further investigations are required to validate and establish their clinical usefulness.

A Five-microRNA Signature as Risk Stratification System in Uterine Corpus Endometrial Carcinoma

BACKGROUND

MicroRNAs (miRs) have been shown to play important roles in various cancers and may be a reliable prognostic marker. However, its prognostic value in endometrial carcinoma (UCEC) needs to be further explored.

OBJECTIVES

The aim of this study was to create a miR-based signature to effectively predict the prognosis for patients with uterine corpus endometrial carcinoma (UCEC).

METHODS

Using UCEC data set in TCGA, we identified differentially expressed miRs between UCEC and healthy endometrial tissues. The LASSO method was used to construct a miR-based signature prognosis index for predicting prognosis in the training cohort. The miR-based signature prognosis index was validated in an independent test cohort. MiRNet tool was applied to perform functional enrichment analysis of this miR-based signature.

RESULTS

A total of 208 miRs were differentially expressed between UCEC and healthy endometrial tissues. Five miRs (miR-652, miR-3170, miR-195, miR-34a, and miR-934) were identified to generate a prognosis index (PI). The five-miR signature is a promising biomarker for predicting the 5-year-survival rate of UCEC with AUC = 0.730. The PI remained an independent prognostic factor adjusted by routine clinicopathologic factors. Using the PI, we could successfully identify the high-risk individuals, furthermore, it still worked in an independent test cohort. The five miRs involved in various pathways associated with cancer.

CONCLUSION

We proposed and validated a five-miR signature that could serve as an independent prognostic predictor of UCECs.

Unveiling the ups and downs of miR-205 in physiology and cancer: transcriptional and post-transcriptional mechanisms

miR-205 plays important roles in the physiology of epithelia by regulating a variety of pathways that govern differentiation and morphogenesis. Its aberrant expression is frequently found in human cancers, where it was reported to act either as tumor-suppressor or oncogene depending on the specific tumor context and target genes. miR-205 expression and function in different cell types or processes are the result of the complex balance among transcription, processing and stability of the microRNA. In this review, we summarize the principal mechanisms that regulate miR-205 expression at the transcriptional and post-transcriptional level, with particular focus on the transcriptional relationship with its host gene. Elucidating the mechanisms and factors regulating miR-205 expression in different biological contexts represents a fundamental step for a better understanding of the contribution of such pivotal microRNA to epithelial cell function in physiology and disease, and for the development of modulation strategies for future application in cancer therapy.

MiRNAs: A Powerful Tool in Deciphering Gynecological Malignancies

Accumulated evidence on the clinical roles of microRNAs (miRNAs) in cancer prevention and control has revealed the emergence of new genetic techniques that have improved the understanding of the mechanisms essential for pathology induction and progression. Comprehension of the modifications and individual differences of miRNAs and their interactions in the pathogenesis of gynecological malignancies, together with an understanding of the phenotypic variations have considerably improved the management of the diagnosis and personalized treatment for different forms of cancer. In recent years, miRNAs have emerged as signaling molecules in biological pathways involved in different categories of cancer and it has been demonstrated that these molecules could regulate cancer-relevant processes, our focus being on malignancies of the gynecologic tract. The aim of this paper is to summarize novel research findings in the literature regarding the parts that miRNAs play in cancer-relevant processes, specifically regarding gynecological malignancy, while emphasizing their pivotal role in the disruption of cancer-related signaling pathways.

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.

miR-205: A Potential Biomedicine for Cancer Therapy

microRNAs (miRNAs) are a class of small non-coding RNAs that regulate the expression of their target mRNAs post transcriptionally. miRNAs are known to regulate not just a gene but the whole gene network (signaling pathways). Accumulating evidence(s) suggests that miRNAs can work either as oncogenes or tumor suppressors, but some miRNAs have a dual nature since they can act as both. miRNA 205 (miR-205) is one such highly conserved miRNA that can act as both, oncomiRNA and tumor suppressor. However, most reports confirm its emerging role as a tumor suppressor in many cancers. This review focuses on the downregulated expression of miR-205 and discusses its dysregulation in breast, prostate, skin, liver, gliomas, pancreatic, colorectal and renal cancers. This review also confers its role in tumor initiation, progression, cell proliferation, epithelial to mesenchymal transition, and tumor metastasis. Restoration of miR-205 makes cells more sensitive to drug treatments and mitigates drug resistance. Additionally, the importance of miR-205 in chemosensitization and its utilization as potential biomedicine and nanotherapy is described. Together, this review research article sheds a light on its application as a diagnostic and therapeutic marker, and as a biomedicine in cancer.

miR-215 Inhibits Colorectal Cancer Cell Migration and Invasion via Targeting Stearoyl-CoA Desaturase

BACKGROUND

This study was aimed at exploring the effects of miR-215 and its target gene stearoyl-CoA desaturase (SCD) on colorectal cancer (CRC) cell migration and invasion.

METHODS

Here, we analyzed the relationship between miR-215 and SCD, as well as the regulation of miR-215 on CRC cells. We constructed wild-type and mutant plasmids of SCD to identify whether SCD was a target gene of miR-215 by using a luciferase reporter assay. The expression of miR-215 and SCD was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. MTT, wound healing, and Transwell assays were applied to determine the effect of miR-215 on CRC cell proliferation, migration, and invasion.

RESULTS

It was found that miR-215 expression was significantly decreased in CRC tissue while SCD was highly expressed compared with those in adjacent normal tissue. The luciferase reporter assay indicated that SCD was a direct target gene of miR-215. Functional analysis revealed that miR-215 overexpression significantly inhibited CRC cell proliferation, migration, and invasion in vitro. In addition, the result of rescue experiments showed that overexpression of SCD could promote the proliferation, migration, and invasion of CRC cells, and the carcinogenic effect of SCD could be inhibited by miR-215.

CONCLUSIONS

Taken together, our findings suggested that miR-215 could inhibit CRC cell migration and invasion via targeting SCD. The result could eventually contribute to the treatment for CRC.

Seminal Plasma Modulates miRNA Expression by Sow Genital Tract Lining Explants

The seminal plasma (SP) modulates the female reproductive immune environment after mating, and microRNAs (miRNAs) could participate in the process. Considering that the boar ejaculate is built by fractions differing in SP-composition, this study evaluated whether exposure of mucosal explants of the sow internal genital tract (uterus, utero-tubal junction and isthmus) to different SP-fractions changed the profile of explant-secreted miRNAs. Mucosal explants retrieved from oestrus sows (n = 3) were in vitro exposed to: Medium 199 (M199, Control) or M199 supplemented (1:40 v/v) with SP from the sperm-rich fraction (SRF), the post-SRF or the entire recomposed ejaculate, for 16 h. After, the explants were cultured in M199 for 24 h to finally collect the media for miRNA analyses using GeneChip miRNA 4.0 Array (Affymetrix). Fifteen differentially expressed (False Discovery Rate (FDR) < 0.05 and Fold-change ≥ 2) miRNAs (11 down- versus 4 up-regulated) were identified (the most in the media of uterine explants incubated with SP from post-SRF). Bioinformatics analysis identified that predicted target genes of dysregulated miRNAs, mainly miR-34b, miR-205, miR-4776-3p and miR-574-5p, were involved in functions and pathways related to immune response. In conclusion, SP is able to elicit changes in the miRNAs profile secreted by female genital tract, ultimately depending SP-composition.

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.

Prognostic Role of microRNA-205 in Human Gynecological Cancer: A Meta-Analysis of Fourteen Studies

Several studies have revealed that miR-205 plays important roles in the development of gynecological cancers and thus may serve as a potential prognostic biomarker, but the current conclusions remain controversial. Therefore, the goal of this study was to explore the prognostic significance and functional mechanisms of miR-205 based on a meta-analysis and bioinformatics investigation. A total of 14 published studies containing 5835 patients were enrolled by searching the PubMed, EMBASE, and Cochrane library databases, 13 (14 datasets) and 5 (6 datasets) of which evaluated the correlations between the expression level of miR-205 and overall survival (OS) or disease-free survival (DFS)/disease-specific survival (DSS)/progression-free survival (PFS)/distant metastasis-free survival (DMFS), respectively. Furthermore, the use of online Kaplan-Meier plotter database analysis supplemented another seven results for OS. Then, a meta-analysis using these 21 and 6 datasets was performed. As a result, the overall analysis failed to demonstrate any significant associations between miR-205 expression and OS (p = 0.267) or DSS/DFS/DMFS/PFS (p = 0.457), but the subgroup analysis suggested that elevated miR-205 predicted a reduced OS for breast cancer (BC) patients (hazard ratio [HR] = 0.84, 95% confidence interval [CI] = 0.72-0.98; p = 0.022), while higher miR-205 was associated with a poor DSS for endometrial cancer (EC) patients (HR = 2.19, 95% CI = 1.45-3.32; p < 0.001). Function prediction analysis indicated that miR-205 may be involved in BC by negatively influencing hub genes, SMARCA5 and SIAH1, whereas miR-205 may participate in EC by negatively modulating BMPR1B because of the presence of interactions of miR-205 with them at 3'-untranslated region and their opposite prognosis outcomes with miR-205. In conclusion, our findings suggest miR-205 may be a promising prognostic biomarker and therapeutic target for BC and EC patients.

lncRNA LA16c‑313D11.11 modulates the development of endometrial cancer by binding to and inhibiting microRNA‑205‑5p function and indirectly increasing PTEN activity

The aim of the present study was to determine the competitive endogenous RNA (ceRNA) network associated with long‑coding RNA (lncRNA) LA16c‑313D11.11 in endometrial cancer (EC). Initially, the expression levels of LA16c‑313D11.11 in 60 EC tissues, 20 atypical hyperplasia endometrium (EAH) tissues and 20 normal endometrium tissues was determined. MicroRNA (miRNA/miR)‑205‑5p mimics and LA16c‑313D11.11 mimics were transfected into HEC‑1A and Ishikawa cells. The expression levels of miR‑205‑5p, LA16c‑313D11.11 and their target proteins were assessed using reverse transcription‑quantitative PCR or western blot analysis. Flow cytometry, Cell Counting kit‑8 assays, Transwell migration assays and wound healing assays were performed to assess the effects of LA16c‑313D11.11 and miR‑205‑5p on the migration and proliferation of tumor cells in vitro. The expression levels of LA16c‑313D11.11 and phosphatase and tensin homolog deleted on chromosome ten (PTEN) in human EAH and EC tissues were significantly decreased, whereas the expression levels of miR‑205‑5p in EAH and EC tissues were significantly increased, compared with the normal endometrium tissues. The expression of LA16c‑313D11.11 in human EC tissues negatively correlated with the expression of miR‑205‑5p. Additionally, the overexpression of LA16c‑313D11.11 significantly reduced the invasion, migration and viability of HEC‑1A and Ishikawa cells in vitro. LA16c‑313D11.11 was shown to regulate the expression of PTEN, and the invasion, migration and viability of HEC‑1A and Ishikawa cells, through its microRNA response element to compete for microRNA‑205‑5p. LA16c‑313D11.11 was also shown to modulate the PI3K/AKT signaling pathway. Therefore, LA16c‑313D11.11 acts as an effective ceRNA associated with a microRNA‑205‑5p‑PTEN axis. LA16c‑313D11.11 may inhibit the development and progression of EC by acting as a sponge of miR‑205‑5p, thus indirectly increasing the expression of PTEN.

MiRNAs in endometrioid endometrial cancer metastatic loci derived from positive lymph nodes

INTRODUCTION

MicroRNAs (miRNAs) take part in tumorigenesis and show aberrant expression levels in cancerous tissues. We aimed to perform miRNA profiling of endometrioid endometrial cancer (EEC) metastatic loci derived from lymph nodes. Identification of aberrant miRNAs in positive lymph nodes could contribute to establishing new diagnostic markers and therapeutic targets.

MATERIAL AND METHODS

During the screening phase of the study, we performed profiling of 754 human miRNAs in endometrioid endometrial cancer tissues, microdissected metastatic loci from lymph nodes and healthy lymph nodes (Taqman Array). Selection of candidate miRNAs and subsequent validation using quantitative reverse transcription polymerase chain reaction (qRT-PCR) in 50 tissue samples were performed.

RESULTS

After the screening phase of the study, five miRNAs were selected (hsa-miR-18b, hsa-miR-148a-5p, hsa-miR-204, hsa-miR-424, hsa-miR-129-1-3p). Validation revealed that miRNA-204 and miRNA-424 were highly downregulated in metastatic tissues compared with endometrial cancer samples (hsa-miR-204-P = .0008; hsa-miR-424-P = .0001). Receiver operating characteristic curves, which were constructed to compare endometrioid endometrial cancer and positive endometrioid endometrial cancer lymph nodes yielded the following area under the curves (AUCs): hsa-miR-204-.802 (96% confidence interval CI 0.676-0.927), hsa-miR-424-.84 (95% CI 0.711-0.969).

CONCLUSIONS

Compared with primary endometrioid endometrial cancer tissue, metastatic loci derived from positive lymph nodes are characterized by profound downregulation of miRNA-204 and miRNA-424.

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.

Exosomal microRNA-205 is involved in proliferation, migration, invasion, and apoptosis of ovarian cancer cells via regulating VEGFA

Background

Recently, the impact of microRNAs (miRNAs) and exosome on ovarian cancer has been assessed in many studies. We aim to explore the mechanism of exosomes transferring miR-205 in ovarian cancer, and confirm its diagnostic value in ovarian cancer.

Methods

The expression of miR-205 of ovarian cancer patients and healthy people was detected by RT-qPCR, and the diagnostic value of miR-205 was evaluated. The exosomes derived from SKOV3 cells were identified. Ovarian cancer SKOV3 donor cells and receptor cells were used to measure the proliferation, migration, invasion, apoptosis and cell cycle by a series of experiments. The binding site between miR-205 and vascular endothelial growth factor A (VEGFA) was evaluated by bioinformatics tool and dual-luciferase reporter gene assay.

Results

MiR-205 was up-regulated in ovarian cancer, and up-regulated miR-205 could enhance the risk of ovarian cancer and was one of its risk factors. After SKOV3 cells-derived exosomes were transiently introduced with miR-205 mimics, the cell proliferation, migration and invasion in ovarian cancer were elevated, the apoptosis of ovarian cancer cells was attenuated, and the epithelial–mesenchymal transition (EMT) protein E-cadherin was down-regulated, while Vimentin was elevated. VEGFA was identified to be a target gene of miR-205.

Conclusion

This study suggests that exosomes from donor ovarian cancer cell SKOV3 shuttled miR-205 could participate in the regulation of the proliferation, migration, invasion, apoptosis as well as EMT progression of receptor SKOV3 cells by targeting VEGFA.

KMT2D deficiency enhances the anti-cancer activity of L48H37 in pancreatic ductal adenocarcinoma

BACKGROUND

Novel therapeutic strategies are urgently needed for patients with a delayed diagnosis of pancreatic ductal adenocarcinoma (PDAC) in order to improve their chances of survival. Recent studies have shown potent anti-neoplastic effects of curcumin and its analogues. In addition, the role of histone methyltransferases on cancer therapeutics has also been elucidated. However, the relationship between these two factors in the treatment of pancreatic cancer remains unknown. Our working hypothesis was that L48H37, a novel curcumin analog, has better efficacy in pancreatic cancer cell growth inhibition in the absence of histone-lysine N-methyltransferase 2D (KMT2D).

AIM

To determine the anti-cancer effects of L48H37 in PDAC, and the role of KMT2D on its therapeutic efficacy.

METHODS

The viability and proliferation of primary (PANC-1 and MIA PaCa-2) and metastatic (SW1990 and ASPC-1) PDAC cell lines treated with L48H37 was determined by CCK8 and colony formation assay. Apoptosis, mitochondrial membrane potential (MMP), reactive oxygen species (ROS) levels, and cell cycle profile were determined by staining the cells with Annexin-V/7-AAD, JC-1, DCFH-DA, and PI respectively, as well as flow cytometric acquisition. In vitro migration was assessed by the wound healing assay. The protein and mRNA levels of relevant factors were analyzed using Western blotting, immunofluorescence and real time-quantitative PCR. The in situ expression of KMT2D in both human PDAC and paired adjacent normal tissues was determined by immunohistochemistry. In vivo tumor xenografts were established by injecting nude mice with PDAC cells. Bioinformatics analyses were also conducted using gene expression databases and TCGA.

RESULTS

L48H37 inhibited the proliferation and induced apoptosis in SW1990 and ASPC-1 cells in a dose- and time-dependent manner, while also reducing MMP, increasing ROS levels, arresting cell cycle at the G2/M stages and activating the endoplasmic reticulum (ER) stress-associated protein kinase RNA-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α/activating transcription factor 4 (ATF4)/CHOP signaling pathway. Knocking down ATF4 significantly upregulated KMT2D in PDAC cells, and also decreased L48H37-induced apoptosis. Furthermore, silencing KMT2D in L48H37-treated cells significantly augmented apoptosis and the ER stress pathway, indicating that KMT2D depletion is essential for the anti-neoplastic effects of L48H37. Administering L48H37 to mice bearing tumors derived from control or KMT2D-knockdown PDAC cells significantly decreased the tumor burden. We also identified several differentially expressed genes in PDAC cell lines expressing very low levels of KMT2D that were functionally categorized into the extrinsic apoptotic signaling pathway. The KMT2D high- and low-expressing PDAC patients from the TCGA database showed similar survival rates,but higher KMT2D expression was associated with poor tumor grade in clinical and pathological analyses.

CONCLUSION

L48H37 exerts a potent anti-cancer effect in PDAC, which is augmented by KMT2D deficiency.

Downregulation of microRNA-205 inhibits cell invasion and angiogenesis of cervical cancer through TSLC1-mediated Akt signaling pathway

Cervical cancer (CC) is a common gynecological cancer and a leading cause of cancer-related deaths in women globally. Therefore, this study explores the action of microRNA-205 (miR-205) in the invasion, migration, and angiogenesis of CC through binding to tumor suppressor lung cancer 1 (TSLC1). Initially, the microarray analysis was used to select the candidate gene and the regulatory microRNA. Then, the target relationship between miR-205 and TSLC1 as well as the expression of miR-205, TSLC1, and p-Akt/total Akt in CC cells were determined. Afterwards, CC cell invasion and migration were detected after the treatment of miR-205 mimics/inhibitors and short hairpin RNA against TSLC1. After coculture of cancer cells and vascular endothelial cells, cell proliferation, tube formation, and microvessel density (MVD) were detected to determine the roles of miR-205 in angiogenesis. Finally, tumor growth in nude mice was measured in vivo. TSLC1 was determined as the candidate gene, which was found to be targeted and negatively regulated by miR-205. Then, downregulated miR-205 or forced TSLC1 expression inhibited invasion, migration, and angiogenesis in CC, corresponding to suppressed cell proliferation, tube formation, and expression of IL-8, VEGF, and bFGF, as well as the inhibited activation of the Akt signaling pathway. Furthermore, downregulation of miR-205 was found to exert an inhibitory role in tumor formation and MVD by elevating TSLC1 in CC in vivo. This study demonstrated that downregulated miR-205 inhibited cell invasion, migration, and angiogenesis in CC by inactivating the Akt signaling pathway via TSLC1 upregulation.

miRNAs as Candidate Biomarker for the Accurate Detection of Atypical Endometrial Hyperplasia/Endometrial Intraepithelial Neoplasia

Endometrial cancer is the most common gynecologic malignancy in developed countries. Estrogen-dependent tumors (type I, endometrioid) account for 80% of cases and non-estrogen-dependent (type II, non-endometrioid) account for the rest. Endometrial cancer type I is generally thought to develop via precursor lesions along with the increasing accumulation of molecular genetic alterations. Endometrial hyperplasia with atypia/Endometrial Intraepithelial Neoplasia is the least common type of hyperplasia but it is the type most likely to progress to type I cancer, whereas endometrial hyperplasia without atypia rarely progresses to carcinoma. MicroRNAs are a class of small, non-coding, single-stranded RNAs that negatively regulate gene expression mainly binding to 3′-untranslated region of target mRNAs. In the current study, we identified a microRNAs signature (miR-205, miR-146a, miR-1260b) able to discriminate between atypical and typical endometrial hyperplasia in two independent cohorts of patients. The identification of molecular markers that can distinguish between these two distinct pathological conditions is considered to be highly useful for the clinical management of patients because hyperplasia with an atypical change is associated with a higher risk of developing cancer. We show that the combination of miR-205, −146a, and −1260b has the best predictive power in discriminating these two conditions (>90%). With the aim to find a biological role for these three microRNAs, we focused our attention on a common putative target involved in endometrial carcinogenesis: the oncosuppressor gene SMAD4. We showed that miRs-146a,−205, and−1260b directly target SMAD4 and their enforced expression induced proliferation and migration of Endometrioid Cancer derived cell lines, Hec1a cells. These data suggest that microRNAs-mediated impairment of the TGF-β pathway, due to inhibition of its effector molecule SMAD4, is a relevant molecular alteration in endometrial carcinoma development. Our findings show a potential diagnostic role of this microRNAs signature for the accurate diagnosis of Endometrial hyperplasia with atypia/Endometrial Intraepithelial Neoplasia and improve the understanding of their pivotal role in SMAD4 regulation.

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.

The Significance Role of microRNA-200c as a Prognostic Factor in Various Human Solid Malignant Neoplasms: A Meta-Analysis

Objective: The aim of this study was to conduct a meta-analysis of 49 relevant studies to evaluate the prognostic value of miRNA-200c in various human malignant neoplasms.

Methods: All relevant studies were identified by searching PubMed, Embase and Web of Science until August 15^st, 2018. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) of miRNA-200c for overall survival (OS) and progression-free survival (PFS)/recurrence-free survival (RFS)/disease-free survival (DFS) were calculated to investigate such associations.

Results: Overall, 49 eligible studies were included in this meta-analysis. Our results showed that high expression of miRNA-200c was significantly correlated with a poor OS in cancer (pooled HR = 1.32, 95% CI: 1.06-1.65), but was not significantly correlated with PFS/RFS/DFS in cancer (pooled HR=1.05, 95% CI: 0.84-1.23). In our subgroup analysis, high miRNA-200c expression predicted a significantly worse OS (pooled HR = 1.50, 95% CI: 1.12-2.01) only in Caucasians. Moreover, high miRNA-200c expression even showed significantly poor OS (pooled HR = 1.88, 95% CI: 1.39-2.54) in blood samples. In addition, a significantly unfavorable OS (pooled HR = 2.69, 95% CI: 1.49-4.85) and (pooled HR = 2.66, 95% CI: 1.07-6.59) associated with up-regulated miRNA-200c expression were observed in breast cancer and endometrial cancer, respectively. Besides, high miRNA-200c expression also showed significantly poor PFS/RFS/DFS (pooled HR=1.66, 95% CI: 1.03-2.67) in breast cancer.

Conclusions: Our findings indicated that high miRNA-200c expression was a promising biomarker for patient survival and disease progression in malignant tumors, especially in breast cancer and endometrial cancer. Considering the insufficient evidence, further large-scale researches and clinical studies were needed to verify these results.

The ambiguous role of microRNA-205 and its clinical potential in pancreatic ductal adenocarcinoma

PURPOSE

Early treatment of pancreatic ductal adenocarcinoma (PDAC) is significantly delayed due to the lack of liquid biopsy markers for early diagnosis at surgically resectable tumor stages. Recent studies suggest that microRNA-205 (miR-205) is involved in PDAC progression by post-transcriptional regulation of epithelial-to-mesenchymal transition (EMT). However, the clinical potential of miR-205 as diagnostic and prognostic marker remains undefined and its exact role in PDAC is still ambiguous. This retrospective study is a substantial contribution to this on-going scientific discussion.

METHODS

Expression analysis of miR-205 and its molecular targets in PDAC cell lines (n = 5), human tissue (n = 73), and blood serum samples (n = 85) by qRT-PCR, tissue microarray immunohistochemistry, and western blot. Descriptive and explorative statistical analysis of miR-205's clinical potential for diagnosis and prognosis of PDAC.

RESULTS

The expression of miR-205 differs more than 2000-fold (p < 0.001) between epithelial and mesenchymal-like human PDAC cell lines correlating with EMT-marker expression of E-cadherin, vimentin, fibronectin, and ZEB-1. Expression of miR-205 is significantly upregulated in carcinoma tissue (eightfold, p = 0.028) and serum (2.3-fold, p = 0.023) of PDAC patients compared to age-matched healthy controls. In our patient collective circulating miR-205 in combination with CA.19-9 outperforms the diagnostic accuracy of CA.19-9 alone with an AUC of 0.890 (p < 0.001), sensitivity of 0.867, and specificity of 0.933. Though non-significant, low expression of circulating miR-205 is more frequent in advanced tumor stages combined with a worse overall survival (6.9 vs. 11.9 months, p = 0.176).

CONCLUSION

Besides its controversial role in carcinogenesis, miR-205 shows high potential as a solid and liquid biopsy marker in PDAC. This result is an urgent call for larger confirmatory multi-center studies.

Oncogenic and Tumor-Suppressive Roles of MicroRNAs with Special Reference to Apoptosis: Molecular Mechanisms and Therapeutic Potential

MicroRNAs (miRNAs) are the non-coding class of minute RNA molecules that negatively control post-transcriptional regulation of various functional genes. These miRNAs are transcribed from the loci present in the introns of functional or protein-coding genes, exons of non-coding genes, or even in the 3'-untranslated region (3'-UTR). They have potential to modulate the stability or translational efficiency of a variety of target RNA [messenger RNA (mRNA)]. The regulatory function of miRNAs has been elucidated in several pathological conditions, including neurological (Alzheimer's disease and Parkinson's disease) and cardiovascular conditions, along with cancer. Importantly, miRNA identification in cancer progression and invasion has evolved as an incipient era in cancer treatment. Several studies have shown the influence of miRNAs on various cancer processes, including apoptosis, invasion, metastasis and angiogenesis. In particular, apoptosis induction in tumor cells through miRNA has been extensively studied. The biphasic mode (up- and down-regulation) of miRNA expression in apoptosis and other cancer processes has already been determined. The findings of these studies could be utilized to develop potential therapeutic strategies for the management of various cancers. The present review critically describes the oncogenic and tumor suppressor role of miRNAs in apoptosis and other cancer processes, therapy resistance, and use of their presence in the body fluids as biomarkers.

Dysregulated microRNA expression profiles in cholangiocarcinoma cell-derived exosomes

AIM

Cholangiocarcinoma (CCA) is a malignant tumor of bile duct epithelial cells. The prognosis of CCA is poor due to lack of effective therapeutic targets and detection at an advanced stage. Exosomes are secreted nano-sized vesicles and contribute to the malignancy of several cancers via transferring their miRNAs between cells. Thus, exosomal miRNAs may serve as new therapeutic targets and potential biomarkers for CCA.

MAIN METHODS

Exosomes were isolated from three different CCA cell lines and normal human cholangiocyte cells, followed by miRNA profiling analysis. Potential role of dysregulated miRNA was investigated by knockdown experiment.

KEY FINDINGS

We found that 38 and 460 miRNAs in CCA exosomes were significantly up- and down-regulated, respectively. Of these differentially expressed miRNAs, the hsa-miR-205-5p and miR-200 family members were markedly up-regulated for 600-1500 folds, whereas the miR-199 family members and their clustered miRNA, hsa-miR-214-3p, were down-regulated for 1000-2000 folds. The expression patterns of these representative exosomal miRNAs were similar to those observed in all types of CCA cells. The target genes of the top ten most up- and down-regulated miRNAs are significantly associated with well-characterized cancer-related pathways. Consistently, knockdown of the most up-regulated miRNA, miR-205-5p, reduced KKU-M213 cell invasion and migration.

SIGNIFICANCE

We have demonstrated the distinct miRNA signatures in exosomes released from CCA cells, compared to normal human cholangiocyte cells. These exosomal miRNAs may have the potential to be novel therapeutic targets and biomarkers for CCA.

MicroRNA-205 is downregulated in hepatocellular carcinoma and inhibits cell growth and metastasis via directly targeting vascular endothelial growth factor A

MicroRNAs (miRs) are an emerging class of non-coding, endogenous and small RNA molecules that serve important functions in tumorigenesis and development. The present study investigated the expression, functions and molecular mechanism underlying miR-205 in hepatocellular carcinoma. miR-205 was downregulated in hepatocellular carcinoma tissues and cell lines. Ectopic miR-205 expression suppressed hepatocellular carcinoma cell proliferation, migration and invasion in vitro. In addition, vascular endothelial growth factor A (VEGFA) was identified as a functional downstream target of miR-205 in hepatocellular carcinoma. Furthermore, knockdown of VEGFA revealed the same functions with miR-205 overexpression in hepatocellular carcinoma cells. These results provided evidence that miR-205 served important functions in the inhibition of hepatocellular carcinoma cells growth and metastasis via directly targeting VEGFA, which indicated that miR-205 may have therapeutic value for hepatocellular carcinoma.

miR‑205 targets YAP1 and inhibits proliferation and invasion in thyroid cancer cells

MicroRNA‑205 (miR‑205) has been reported to be downregulated, and serves critical roles in the pathogenesis and progression of several types of cancer, including breast, prostate and lung cancer. However, the underlying mechanism of miR‑205 in thyroid cancer remains unclear. In the present study, it was demonstrated that the expression of miR‑205 was reduced in thyroid cancer tissues compared with non‑cancer tissues. In addition, miR‑205‑knockdown models in the BHT‑101 cell line and ectopic expression models in the 8505‑C cell line were used to measure the biological functions of miR‑205. The results indicated that miR‑205 inhibited certain aspects of thyroid cancer, including cell proliferation, migration and invasion. Furthermore, Yes‑associated protein 1 (YAP1) was identified as a target gene of miR‑205 and its expression was negatively correlated with that of miR‑205 in thyroid cancer tissues. Depletion of YAP1 partially reduced the anti‑miR‑205‑induced cell growth and invasion. The results of the present study suggested that the tumor suppressive functions of miR‑205 via targeting YAP1 could be a novel target for the treatment of thyroid cancer.

Locked nucleic acid-inhibitor of miR-205 decreases endometrial cancer cells proliferation in vitro and in vivo

Pathogenesis of endometrial cancer has been connected with alterations of microRNA expression and in particular miR-205 up–regulation was consistently reported in this carcinoma. Presented study aimed to investigate if inhibition of miR-205 expression using LNA-modified-nucleotide would attenuate endometrial cancer cells proliferation in vitro and in vivo.

In the course of the study we found that the proliferation of endometrial cancer cells (HEC-1-B, RL-95, KLE, Ishikawa) transfected with LNA-miR-205-inhibitor and evaluated using real time cell monitoring as well as standard cell proliferation assay, was significantly decreased. Next, LNA-miR-205-inhibitor was used to assess the in vivo effects of miR-205 inhibition of endometrial cancer growth. Cby.Cg-Foxn1<nu>/cmdb mice bearing endometrial cancer xenografts were intraperitoneally injected with nine dosages of 25mg/kg of miR-205-LNA-inhibitor or scramble control or phosphatase buffered saline and were observed for 32 days. We found that systemic administration of miR-205-LNA-inhibitor was technically possible, and exerted inhibitory effect on endometrial cancer xenograft growth in vivo with only mild toxic effects in treated animals.

In conclusion our results suggest that systemic delivery of miR-205-LNA-inhibitor is feasible, devoid of significant toxicity, and could be a promising treatment strategy for endometrial cancer. Therefore it warrants further studies in other animal models.

Association of microRNA-200c expression levels with clinicopathological factors and prognosis in endometrioid endometrial cancer

INTRODUCTION

MicroRNAs (miRNAs) are regulators of gene expression, which play an important role in many critical cellular processes including apoptosis, proliferation and cell differentiation. Aberrant miRNA expression has been reported in a variety of human malignancies. Therefore, miRNAs may be potentially used as cancer biomarkers. miRNA-200c, which is a member of the miRNA-200 family, might play an essential role in tumor progression. The purpose of this study was to evaluate the prognostic and clinical significance of miRNA-200c in women with endometrioid endometrial cancer.

MATERIAL AND METHODS

Total RNA extraction from 90 archival formalin-fixed paraffin-embedded tissue samples of endometri-oid endometrial cancer and 10 normal endometrium samples was performed. After cDNA synthesis, real-time polymerase chain reaction was conducted and relative expression of miRNA-200c was assessed. Then, miRNA-200c expression levels were evaluated with regard to clinicopathological characteristics.

RESULTS

The expression levels of miRNA-200c were significantly increased in endometrioid endometrial cancer samples. Expression of miRNA-200c maintained at significantly higher levels in the early stage endometrioid endometrial cancer compared with more advanced stages. In the Kaplan-Meier analysis, lower levels of miRNA-200c expression were associated with inferior survival.

CONCLUSIONS

Expression levels of miRNA-200c might be associated with clinicopathological factors and survival in endometrioid endometrial cancer.

Proliferation-associated miRNAs-494, -205, -21 and -126 detected by in situ hybridization: expression and prognostic potential in breast carcinoma patients

PURPOSE

To visualize by in situ hybridization (ISH) the levels of a set of proliferation-associated miRNAs and to evaluate their impact and clinical applicability in prognostication of invasive breast carcinoma.

METHODS

Tissue specimen from breast carcinoma patients were investigated for miRNAs-494, -205, -21 and -126. Prognostic associations for levels of miRNAs were analyzed based on complete clinical data and up to 22.5-year follow-up of the patient material (n = 285). For detection of the miRNAs, an automated sensitive protocol applying in situ hybridization was developed.

RESULTS

MiRNA-494 indicated prognostic value for patients with invasive breast carcinoma. Among node-negative disease reduced level of miRNA-494 predicted 8.5-fold risk of breast cancer death (p = 0.04). Altered levels and expression patterns of the studied miRNAs were observed in breast carcinomas as compared to benign breast tissue.

CONCLUSIONS

The present paper reports for the first time on the prognostic value of miRNA-494 in invasive breast cancer. Particularly, detection of miRNA-494 could benefit patients with node-negative breast cancer in identifying subgroups with aggressive disease. Based on our experience, the developed automatic ISH method to visualize altered levels of miRNAs-494, -205, -21 and -126 could be applied to routine pathology diagnostics providing that conditions of tissue treatment, especially fixation delays, are managed.

Short‑term vagus nerve stimulation reduces myocardial apoptosis by downregulating microRNA‑205 in rats with chronic heart failure

Previous studies have reported that short-term vagus nerve stimulation (VNS) improves cardiac function in rats with chronic heart failure (CHF). The molecular mechanisms are unclear. The potential effect of microRNA (miR)-205 in apoptosis of short-term VNS was examined. A total of 3 weeks after inducing CHF, the rats were divided into three groups: Sham stimulation in sham operated rats, sham stimulation in CHF rats (CHF-SS), and treated with VNS in CHF rats (CHF-VNS). The right vagus nerve of the neck was stimulated for 72 h in CHF rats with rectangular pulses of 40 msec duration at 1 Hz and 5 V. miR-205 was focused on, which exhibited differential expression in the miRNA microarray analysis of CHF rats, and the effects of VNS on apoptosis were examined. It was verified that the expression level of miR-205 in the CHF-SS group was increased, and the expression was reduced in the CHF-VNS group. Furthermore, mimics or inhibitor of miR-205 was transfected into H9c2 to investigate its function on apoptosis. Baculoviral IAP repeat-containing protein 2 (Birc2) was confirmed a target of miR-205 through a dual luciferase reporter assay and western blotting. It was demonstrated that downregulated miR-205 decreased apoptosis in H9c2 cells. The apoptosis-associated proteins were further detected in H9c2 cells and rat tissue. The mRNA and protein expression levels of caspase-3 and Bcl-2-associated X protein were decreased in the CHF-VNS group, the expression of Birc2 and B-cell lymphoma 2 were increased. The results were consistent with the in vitro study in the miR-205 inhibitor group. The present study demonstrated that short-term VNS decreased apoptosis by downregulating miR-205 in rats with CHF. Therefore, the results of the present study provide basic evidence for short-term VNS in the clinical treatment of CHF.

miR-205 promotes epithelial-mesenchymal transition by targeting AKT signaling in endometrial cancer cells

AIM

AKT signaling regulates multiple biological processes and expresses in various cancers. miR-205 plays complex roles in tumorigenesis and tumor progression by acting either as a tumor suppressor or an oncogene depending on the tumor type. Here we describe the molecular mechanism of miR-205 regulating epithelial-mesenchymal transition by activation of AKT signaling in endometrial cancer cells HEC-50B and HEC-1-A.

MATERIAL AND METHODS

The proliferation of HEC-50B cells transfected with miR-205 mimic was assessed by WST-1 assay. The migration and invasion were evaluated by BD transwell migration and matrigel invasion assays. The EMT markers were detected by Western blot.

RESULTS

We found that miR-205 increased the proliferation in HEC-50B cells. The migration and invasion of HEC-50B cells and HEC-1-A cells were enhanced by miR-205. When HEC-50B cells and HEC-1-A cells were treated with anti-miR-205 inhibitor, the migration and invasion were decreased as compared with the negative control. The overexpression of miR-205 inhibited E-cadherin expression and promoted Snail expression by activation of AKT and downregulation of glycogen synthase kinase 3β. However, after the HEC-50B cells and HEC-1-A cells were treated with anti-miR-205 inhibitor, E-cadherin expression was increased and Snail protein level was decreased by inhibition of AKT expression.

CONCLUSION

Our data strongly suggest that miR-205 plays an important role in endometrial cancer migration and invasion by targeting the AKT pathway. Our data highlight miR-205 as a potential molecular target for endometrial cancer treatment.

Upregulation of MiR-205 under hypoxia promotes epithelial-mesenchymal transition by targeting ASPP2

The epithelial–mesenchymal transition (EMT) is one of the crucial procedures for cancer invasion and distal metastasis. Despite undergoing intensive studies, the mechanisms underlying EMT remain to be completely elucidated. Here, we identified that apoptosis-stimulating protein of p53-2 (ASPP2) is a novel target of MiR-205 in various cancers. Interestingly, the binding site of MiR-205 at the 3′-untranslated region of ASPP2 was highly conserved among different species. An inverse correlation between MiR-205 and ASPP2 was further observed in vivo in cervical cancers, suggesting MiR-205 may be an important physiological inhibitor of ASPP2. Hypoxia is a hallmark of solid tumor microenvironment and one of such conditions to induce EMT. Notably, MiR-205 was remarkably induced by hypoxia in cervical and lung cancer cells. A marked suppression of ASPP2 was observed simultaneously. Further studies confirmed that hypoxia-induced ASPP2 suppression was mainly attributed to the elevated MiR-205. Interestingly, the alteration of MiR-205/ASPP2 under hypoxia was accompanied with the decreased epithelial marker E-cadherin and increased mesenchymal marker Vimentin, as well as a morphological transition from the typical cobblestone-like appearance to the mesenchymal-like structure. More importantly, MiR-205 mimics or ASPP2 silencing similarly promoted EMT process. By contrast, ASPP2 recovery or MiR-205 inhibitor reversed MiR-205-dependent EMT. Further studies demonstrated that the newly revealed MiR-205/ASPP2 axis promoted cell migration and also increased cell proliferation both in vivo and in vitro. These data together implicated a critical impact of MiR-205/ASPP2 on promoting EMT. MiR-205/ASPP2 may be potential diagnostic and therapeutic biomarkers in cervical and lung cancers.

Overexpression of microRNA-205 predicts lymph node metastasis and indicates an unfavorable prognosis in endometrial cancer

As an integral component of the surgical staging system, lymphadenectomy for patients with endometrial cancer (EC) remains controversial, particularly in clinical stage I disease that includes not only low-risk, but also high-risk subgroups. In order to maximize the therapeutic effect of lymph node excision for high-risk patients who can potentially obtain survival benefits from it while minimizing its reverse effects in low-risk patients, pre-operative risk stratification of lymph node metastasis is necessary. The upregulation of microRNA-205 (miR-205) in carcinoma of the endometrium has been consistently reported recently and has been found to correlate with poor survival. The current study aimed to investigate whether the overexpression of miR-205 in curettage samples of EC could identify patients who are at a high risk for lymph node metastasis prior to surgery and validate the role of miR-205 as a prognostic marker in EC. Relative quantification detection of miR-205 in curettage and hysterectomy specimens of patients with EC was performed. Prediction of lymph node metastasis based on miR-205 expression, as well as tumor type and grade in curettage samples, was performed for all EC patients and patients with clinical stage I disease. Moreover, survival analysis was conducted. It was observed that miR-205 was significantly and consistently elevated in the curettage and hysterectomy samples of EC relative to normal controls. Furthermore, the overexpression of miR-205 could predict lymph node metastasis with a high accuracy and was revealed again to be associated with a poor prognosis in EC. Prospective and multicentric studies are required to further clarify the value of miR-205 as a promising predictor to stratify risk for lymph node metastasis in EC.

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.

MicroRNA and gynecologic cancers

AIM

Gynecologic malignancies are serious problems in female health. Here we aim to discuss the involvement of microRNA (miRNA) in the pathogenesis of gynecologic cancers and use of miRNA profiles for diagnosis of diseases.

METHODS

In order to obtain information needed for this review, we searched the PubMed database with the following keywords: miRNA and ovarian cancer; miRNA and cervical cancer; and miRNA and endometrial cancer.

RESULTS

Recent explosive investigations in the field have dramatically expanded our knowledge of the roles of miRNA in the pathology of gynecologic malignancies. In ovarian cancer, miRNA participates in the development of drug resistance. In cervical cancer and endometrial cancer, miRNA play essential roles in important oncogenic processes, including cell proliferation, migration and metastasis. miRNA also have high potentials to be used as biomarkers in these diseases.

CONCLUSION

Further validation of the studies and improvement of the methods will result in the broader use of miRNA in the diagnosis of diseases as well as in understanding of the pathomechanisms of gynecologic cancers.

Prognostic significance of microRNA-200c in various types of cancer: An updated meta-analysis of 34 studies

Previous studies have indicated that miR-200c is a promising cancer biomarker. However, different studies have presented conflicting results. Therefore, the aim of the present study was to perform a meta-analysis of miR-200c based on 34 relevant studies. The Materials and methods sections of papers were carefully identified using the databases PubMed, Web of Science and Embase for publications up to December 4, 2015. Pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were systematically calculated to investigate the association between the expression of miR-200c and cancer prognosis. The results demonstrated that elevated expression levels of miR-200c indicated significantly worse overall survival rates (HR=1.37, 95% CI: 1.01, 1.85), and a high level of miR-200c was considered an indicator of an unfavorable prognosis in patients from Europe and America (HR=1.85, 95% CI: 1.27, 2.69). Furthermore, overexpression of miR-200c was significantly associated with progression of the disease in the subgroups of tissue and blood samples (HR=0.68 and 2.45, respectively), and inferior overall survival rates for the blood subgroup were revealed (HR=2.21, 95% CI: 1.04, 4.72). In addition, miR-200c was of prognostic value in several disease subgroups. Taken together, high expression levels of miR-200c are of significant prognostic value in various human malignancies.