MicroRNA-503 suppresses proliferation and cell-cycle progression of endometrioid endometrial cancer by negatively regulating cyclin D1

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.

Human umbilical cord blood mesenchymal stem cells-derived exosomal microRNA-503-3p inhibits progression of human endometrial cancer cells through downregulating MEST

Endometrial cancer (EC) is a group of epithelial malignant tumors that occur in the endometrium. The specific pathogenesis is not revealed, hence, the goal of this study was to investigate the influence of human umbilical cord blood mesenchymal stem cells (hUMSCs)-derived exosomal microRNA-503-3p (miR-503-3p) on human EC cells by mediating mesoderm-specific transcript (MEST). The binding relationship between MiR-503-3p and MEST was searched. HUMSCs were collected and exosomes (Exos) were isolated and identified. Human EC cell lines HEC-1B and RL95-2 were transfected with elevated miR-503-3p or silenced MEST vector or co-cultured with Exos to figure their roles in biological functions of EC cells. The in vitro effect of miR-503-3p, MEST, and Exos on EC cells was further verified in vivo. MEST was a target of miR-503-3p. Overexpression of miR-503-3p or reduction of MEST suppressed the biological functions of EC cells. Enhanced MEST expression mitigated the role of upregulated miR-503-3p on the growth of EC cells. HUMSCs-derived Exos suppressed EC cell growth, upregulated miR-503-3p-modified HUMSCs-derived Exos had a more obvious inhibitory effect on EC cell growth. The anti-tumor effect of elevated miR-503-3p, silenced MEST, and HUMSCs-derived Exos were verified in nude mice. This study highlights that hUMSCs-derived exosomal miR-503-3p inhibits EC development by suppressing MEST, which is of great benefit to EC therapy.

H19X-encoded miR-322(424)/miR-503 regulates muscle mass by targeting translation initiation factors

BACKGROUND

Skeletal muscle atrophy is a debilitating complication of many chronic diseases, disuse conditions, and ageing. Genome-wide gene expression analyses have identified that elevated levels of microRNAs encoded by the H19X locus are among the most significant changes in skeletal muscles in a wide scope of human cachectic conditions. We have previously reported that the H19X locus is important for the establishment of striated muscle fate during embryogenesis. However, the role of H19X-encoded microRNAs in regulating skeletal mass in adults is unknown.

METHODS

We have created a transgenic mouse strain in which ectopic expression of miR-322/miR-503 is driven by the skeletal muscle-specific muscle creatine kinase promoter. We also used an H19X mutant mouse strain in which transcription from the locus is interrupted by a gene trap. Animal phenotypes were analysed by standard histological methods. Underlying mechanisms were explored by using transcriptome profiling and validated in the two animal models and cultured myotubes.

RESULTS

Our results demonstrate that the levels of H19X microRNAs are inversely related to postnatal skeletal muscle growth. Targeted overexpression of miR-322/miR-503 impeded skeletal muscle growth. The weight of gastrocnemius muscles of transgenic mice was only 54.5% of the counterparts of wild-type littermates. By contrast, interruption of transcription from the H19X locus stimulates postnatal muscle growth by 14.4-14.9% and attenuates the loss of skeletal muscle mass in response to starvation by 12.8-21.0%. Impeded muscle growth was not caused by impaired IGF1/AKT/mTOR signalling or a hyperactive ubiquitin-proteasome system, instead accompanied by markedly dropped abundance of translation initiation factors in transgenic mice. miR-322/miR-503 directly targets eIF4E, eIF4G1, eIF4B, eIF2B5, and eIF3M.

CONCLUSIONS

Our study illustrates a novel pathway wherein H19X microRNAs regulate skeletal muscle growth and atrophy through regulating the abundance of translation initiation factors, thereby protein synthesis. The study highlights how translation initiation factors lie at the crux of multiple signalling pathways that control skeletal muscle mass.

LncRNA DLGAP1-AS2 regulates miR-503/cyclin D1 to promote cell proliferation in non-small cell lung cancer

Background

LncRNA DLGAP1-AS2 plays an oncogenic role in glioma, while its role in other cancers is unknown. This study aimed to study the role of DLGAP1-AS2 in non-small cell lung cancer (NSCLC).

Methods

Expression of DLGAP1-AS2 in NSCLC and paired non-tumor tissues from 64 NSCLC patients and the prognostic value of DLGAP1-AS2 for NSCLC were analyzed by performing a 5-year follow-up study. The interaction between DLGAP1-AS2 and miR-503 was confirmed by dual luciferase reporter assay, and their relationship was explored in NSCLC cells transfected with DLGAP1-AS2 expression vector or miR-503 mimic. The roles of DLGAP1-AS2 and miR-503 in regulating cyclin D1 expression were analyzed by RT-qPCR and Western blot. Cell proliferation was analyzed by CCK-8 assay.

Results

DLGAP1-AS2 was upregulated in NSCLC and predicted poor survival. Interaction between DLGAP1-AS2 and miR-503 was confirmed by dual luciferase activity assay. Overexpression experiments showed that DLGAP1-AS2 and miR-503 overexpression failed to significantly affect the expression of each other. Interestingly, DLGAP1-AS2 overexpression upregulated cyclin D1, a target of miR-503, increased cell proliferation and reduced the effects of miR-503 overexpression on cyclin D1 expression and cell proliferation.

Conclusions

DLGAP1-AS2 may regulate miR-503/cyclin D1 to promote cell proliferation in NSCLC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01633-0.

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.

LncRNA PVT1 promotes cervical cancer progression by sponging miR-503 to upregulate ARL2 expression

Cervical cancer (CC) is a huge threat to the health of women worldwide. Long non-coding RNA plasmacytoma variant translocation 1 gene (PVT1) was proved to be associated with the development of diverse human cancers, including CC. Nevertheless, the exact mechanism of PVT1 in CC progression remains unclear. Levels of PVT1, microRNA-503 (miR-503), and ADP ribosylation factor-like protein 2 (ARL2) were measured by quantitative reverse transcription-polymerase chain reaction or western blot assay. 3-(4,5)-Dimethylthiazole-2-y1)-2,5-biphenyl tetrazolium bromide (MTT) and flow cytometry were used to examine cell viability and apoptosis, respectively. For migration and invasion detection, transwell assay was performed. The interaction between miR-503 and PVT1 or ARL2 was shown by dual luciferase reporter assay. A nude mouse model was constructed to clarify the role of PVT1 in vivo. PVT1 and ARL2 expressions were increased, whereas miR-503 expression was decreased in CC tissues and cells. PVT1 was a sponge of miR-503, and miR-503 targeted ARL2. PVT1 knockdown suppressed proliferation, migration, and invasion of CC cells, which could be largely reverted by miR-503 inhibitor. In addition, upregulated ARL2 could attenuate si-PVT1-mediated anti-proliferation and anti-metastasis effects on CC cells. Silenced PVT1 also inhibited CC tumor growth in vivo. PVT1 knockdown exerted tumor suppressor role in CC progression via the miR-503/ARL2 axis, at least in part.

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.

The microRNA-424/503 cluster: A master regulator of tumorigenesis and tumor progression with paradoxical roles in cancer

MicroRNAs (miRNAs) are a group of non-coding RNAs that play a crucial role in post-transcriptional gene regulation and act as indispensable mediators in several critical biological processes, including tumorigenesis, tissue homeostasis, and regeneration. MiR-424 and miR-503 are intragenic miRNAs that are clustered on human chromosome Xq26.3. Previous studies have reported that both miRNAs are dysregulated and play crucial but paradoxical roles in tumor initiation and progression, involving different target genes and molecular pathways. Moreover, these two miRNAs are concomitantly expressed in several cancer cells, indicating a coordinating function as a cluster. In this review, the roles and regulatory mechanisms of miR-424, miR-503, and miR-424/503 cluster are summarized in different types of cancers.

An olaparib window-of-opportunity trial in patients with early-stage endometrial carcinoma: POLEN study

OBJECTIVE

Olaparib is a potent inhibitor of poly(ADP-ribose) polymerase (PARP)-1, 2, and 3 with potential activity in endometrial cancer (EC).

METHODS

In this window-of-opportunity trial, women with operable type 1 EC received olaparib oral tablets (300mg) twice daily for 28days before surgery. The primary objective was to evaluate the effects of olaparib on EC in tissue samples taken at baseline and at treatment completion. Signal of activity was defined as significant changes in the expression of the cell cycle-related proteins cyclin D1, Ki67, and cleaved caspase-3.

RESULTS

A total of 31 patients were included in the biomarker analysis. The median time of olaparib exposure was 24 days (1-39). Significant inhibition was found for cyclin D1 (p < 0.01), but not for Ki67 and active caspase 3 immunostaining. PARP-1 levels positively correlated with cyclin D1 levels (rho = 0.661, p = 0.0001). Both PARP-1 and cyclin D1 levels were significantly lower (p = 0.022 and p = 0.004, respectively) in patients with ARID1A[-] tumors than ARID1A[+] tumors. A significant relationship between plasma olaparib concentrations and decreased GLUT1 activity was observed (r = -0.5885; p < 0.05). Drug-related toxicity consisted mostly of gastrointestinal and grade 1 or 2 adverse events.

CONCLUSIONS

Olaparib reduced expression of cyclin D1, which positively correlated with PARP-1 levels. This effect was more evident in ARID1A-deficient tumors. Olaparib further induced inhibition of GLUT1 plasma activity. Our findings could have noteworthy implications in predicting which patients with EC would benefit from olaparib-based strategies.

Comparison of miRNA Expression Profiles between HIV-1 and HIV-2 Infected Monocyte-Derived Macrophages (MDMs) and Peripheral Blood Mononuclear Cells (PBMCs)

During the progression of HIV-1 infection, macrophage tropic HIV-1 that use the CCR5 co-receptor undergoes a change in co-receptor use to CXCR4 that is predominately T cell tropic. This change in co-receptor preference makes the virus able to infect T cells. HIV-2 is known to infect MDMs and T cells and is dual tropic. The aim of this study was to elucidate the differential expression profiles of host miRNAs and their role in cells infected with HIV-1/HIV-2. To achieve this goal, a comparative global miRNA expression profile was determined in human PBMCs and MDMs infected with HIV-1/HIV-2. Differentially expressed miRNAs were identified in HIV-1/HIV-2 infected PBMCs and MDMs using the next-generation sequencing (NGS) technique. A comparative global miRNA expression profile in infected MDMs and PBMCs with HIV-1 and HIV-2 identified differential expression of several host miRNAs. These differentially expressed miRNAs are likely to be involved in many signaling pathways, like the p53 signaling pathway, PI3K-Akt signaling pathways, MAPK signaling pathways, FoxO signaling pathway, and viral carcinogenesis. Thus, a comparative study of the differential expression of host miRNAs in MDMs and T cell in response to HIV-1 and HIV-2 infection will help us to identify unique biomarkers that can differentiate HIV-1 and HIV-2 infection.

Long non-coding RNA LINC00460 promotes proliferation and inhibits apoptosis of cervical cancer cells by targeting microRNA-503-5p

Long non-coding RNAs are associated with the pathogenesis of cancers. Moreover, LINC00460 is involved in the development of multiple cancers. However, the function of LINC00460 in cervical cancer (CC) remains inconclusive. Herein, CC tissues and tumor-adjacent tissues were collected from patients. The effect of LINC00460 silencing in cell proliferation and apoptosis in CC was explored in vitro and in vivo. Additionally, the interaction between LINC00460 and miR-503-5p was analyzed using dual luciferase reporter assay. The expression of genes and proteins was assayed using quantitative real-time PCR, western blotting and immunohistochemistry, cell viability using MTT assay, cell cycle distribution using flow cytometry, cell apoptosis using Annexin V staining, Hoechst staining and TUNEL assay. LINC00460 levels in CC tissues were higher than tumor-adjacent tissues. LINC00460 silencing suppressed proliferation and promoted apoptosis of CC cells as evidenced by decreased cell viability, inhibited proliferation-related protein and cell cycle protein expressions and G1/S transition, increased apoptotic cells and Hoechst-positive cells, and enhanced apoptosis-related protein expressions. LINC00460 could bind to miR-503-5p and LINC00460 silencing enhanced miR-503-5p expression and inhibited its target gene expressions in CC cells. MiR-503-5p inhibition reversed LINC00460 silencing-caused inhibition of cell proliferation and miR-503-5p target gene expressions, and promotion of cell apoptosis. LINC00460 silencing also attenuated tumor growth, promoted miR-503-5p levels and cell apoptosis, and inhibited cell proliferation and miR-503-5p target gene expressions in tumor tissues. Hence, LINC00460 functioned as an oncogene in CC that affected cell proliferation and apoptosis via sponging miR-503-5p. This study provides a novel therapeutic target for CC.

Identification of long noncoding RNA RP11-89K21.1 and RP11-357H14.17 as prognostic signature of endometrial carcinoma via integrated bioinformatics analysis

Background

Endometrial carcinoma (EC) is one of the most common malignant tumors in gynecology. The potential functions and mechanisms of long noncoding RNAs (lncRNAs) in the occurrence and progression of EC remains unclear. It’s meaningful to explore lncRNAs signature for providing prognostic value of EC.

Methods

The differentially expressed lncRNAs and their prognostic values in EC were investigated based on The Cancer Genome Atlas (TCGA) database; the transcriptional factors (TFs), the competing endogenous RNA (ceRNA) mechanism, functional regulatory network and immune infiltration of RP11-89K21.1 and RP11-357H14.17 were further explored by various bioinformatics tools and databases.

Results

We firstly identified high expression of RP11-89K21.1 and RP11-357H14.17 were closely associated with shorten overall survival (OS) and poor prognosis in patients with EC. We also elucidated the networks of transcription factor and co-expression genes associated with RP11-89K21.1 and RP11-357H14.17. Furthermore, the ceRNA network mechanism was successfully constructed through 2 lncRNAs (RP11-89K21.1 and RP11-357H14.17), 11 miRNAs and 183 mRNAs. Functional enrichment analysis revealed that the targeting genes of RP11-89K21.1 and RP11-357H14.17 were strongly associated with microRNAs in cancer, vessel development, growth regulation, growth factor and cell differentiation, and involved in pathways including pathways in cancer, microRNAs in cancer and apoptotic signaling pathway.

Conclusions

We demonstrated for the first time that RP11-89K21.1 and RP11-357H14.17 may play crucial roles in the occurrence, development and malignant biological behavior of EC, and can be regarded as potential prognostic biomarkers for EC.

Genome-wide profiling of miRNA expression patterns in tubal endometriosis

MicroRNA (miRNA) expression profiles in tubal endometriosis (EM) are still poorly understood. In this study, we analyzed the differential expression of miRNAs and the related gene networks and signaling pathways in tubal EM. Four tubal epithelium samples from tubal EM patients and five normal tubal epithelium samples from uterine leiomyoma patients were collected for miRNA microarray. Bioinformatics analyses, including Ingenuity Pathway Analysis (IPA), Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, were performed. Quantitative real-time polymerase chain reaction (qRT-PCR) validation of five miRNAs was performed in six tubal epithelium samples from tubal EM and six from control. A total of 17 significantly differentially expressed miRNAs and 4343 potential miRNA-target genes involved in tubal EM were identified (fold change >1.5 and FDR-adjusted P value <0.05). IPA indicated connections between miRNAs, target genes and other gynecological diseases like endometrial carcinoma. GO and KEGG analysis revealed that most of the identified genes were involved in the mTOR signaling pathway, SNARE interactions in vesicular transport and endocytosis. We constructed an miRNA-gene-disease network using target gene prediction. Functional analysis showed that the mTOR pathway was connected closely to tubal EM. Our results demonstrate for the first time the differentially expressed miRNAs and the related signal pathways involved in the pathogenesis of tubal EM which contribute to elucidating the pathogenic mechanism of tubal EM-related infertility.

Genetic and Epigenetic Modification of Rat Liver Progenitor Cells via HNF4α Transduction and 5' Azacytidine Treatment: An Integrated miRNA and mRNA Expression Profile Analysis

Neonatal liver-derived rat epithelial cells (rLEC) from biliary origin are liver progenitor cells that acquire a hepatocyte-like phenotype upon sequential exposure to hepatogenic growth factors and cytokines. Undifferentiated rLEC express several liver-enriched transcription factors, including the hepatocyte nuclear factors (HNF) 3β and HNF6, but not the hepatic master regulator HNF4α. In this study, we first investigated the impact of the ectopic expression of HNF4α in rLEC on both mRNA and microRNA (miR) level by means of microarray technology. We found that HNF4α transduction did not induce major changes to the rLEC phenotype. However, we next investigated the influence of DNA methyl transferase (DNMT) inhibition on the phenotype of undifferentiated naïve rLEC by exposure to 5′ azacytidine (AZA), which was found to have a significant impact on rLEC gene expression. The transduction of HNF4α or AZA treatment resulted both in significantly downregulated C/EBPα expression levels, while the exposure of the cells to AZA had a significant effect on the expression of HNF3β. Computationally, dysregulated miRNAs were linked to target mRNAs using the microRNA Target Filter function of Ingenuity Pathway Analysis. We found that differentially regulated miRNA–mRNA target associations predict ectopic HNF4α expression in naïve rLEC to interfere with cell viability and cellular maturation (miR-19b-3p/NR4A2, miR30C-5p/P4HA2, miR328-3p/CD44) while it predicts AZA exposure to modulate epithelial/hepatic cell proliferation, apoptosis, cell cycle progression and the differentiation of stem cells (miR-18a-5p/ESR1, miR-503-5p/CCND1). Finally, our computational analysis predicts that the combination of HNF4α transduction with subsequent AZA treatment might cause changes in hepatic cell proliferation and maturation (miR-18a-5p/ESR1, miR-503-5p/CCND1, miR-328-3p/CD44) as well as the apoptosis (miR-16-5p/BCL2, miR-17-5p/BCL2, miR-34a-5p/BCL2 and miR-494-3p/HMOX1) of naïve rLEC.

The Role of MicroRNAs in Muscle Tissue Development in Beef Cattle

In this review, we highlight information on microRNA (miRNA) identification and functional characterization in the beef for muscle and carcass composition traits, with an emphasis on Qinchuan beef cattle, and discuss the current challenges and future directions for the use of miRNA as a biomarker in cattle for breeding programs to improve meat quality and carcass traits. MicroRNAs are endogenous and non-coding RNA that have the function of making post-transcriptional modifications during the process of preadipocyte differentiation in mammals. Many studies claim that diverse miRNAs have an impact on adipogenesis. Furthermore, their target genes are associated with every phase of adipocyte differentiation. It has been confirmed that, during adipogenesis, several miRNAs are differentially expressed, including miR-204, miR-224, and miR-33. The development of mammalian skeletal muscle is sequentially controlled by somite commitment into progenitor cells, followed by their fusion and migration, the proliferation of myoblasts, and final modification into fast- and slow-twitch muscle fibers. It has been reported that miRNA in the bovine MEG3-DIO3 locus has a regulatory function for myoblast differentiation. Likewise, miR-224 has been associated with controlling the differentiation of bovine adipocytes by targeting lipoprotein lipase. Through the posttranscriptional downregulation of KLF6, miR-148a-3p disrupts the proliferation of bovine myoblasts and stimulates apoptosis while the miR-23a~27a~24-2 cluster represses adipogenesis. Additional to influences on muscle and fat, bta-mir-182, bta-mir-183, and bta-mir-338 represent regulators of proteolysis in muscle, which influences meat tenderness.

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

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

MicroRNA-503 serves an oncogenic role in retinoblastoma progression by directly targeting PTPN12

Numerous studies have demonstrated that microRNAs (miRNAs or miRs) are abnormally expressed in retinoblastoma (RB). miRNAs may serve a role in oncogene or tumor-suppressor activity in RB genesis and development by modulating various biological processes. miRNAs therefore, may be effective therapeutic targets for miRNA-based therapy in patients with RB. Recently it has been revealed that miR-503 may serve a role in various types of human cancer. However, the expression and functional roles of miR-503 are rarely reported in RB. In the current study, the expression of miR-503 was significantly upregulated in RB tissues and cell lines. In addition, Cell Counting Kit-8 and in vitro invasion assays were performed to assess cell proliferation and invasion, respectively. The results of the present study revealed that miR-503 inhibition impeded RB in vitro cell proliferation and invasion. Furthermore, protein tyrosine phosphatase nonreceptor type 12 (PTPN12) was demonstrated to be a direct target gene of miR-503 in RB cells. PTPN12 overexpression also led to the downregulation of miR-503 in RB cell proliferation and invasion. PTPN12 knockdown could therefore abrogate the effects of miR-503 downregulation in RB cells. In conclusion, the results demonstrated that miR-503 may serve a role in RB oncogenic activity progression by directly targeting PTPN12. Therefore, miR-503 may be a target for effective therapy in patients with RB.

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.

MicroRNA-551b-3p inhibits tumour growth of human cholangiocarcinoma by targeting Cyclin D1

MicroRNAs (miRNAs) are powerful regulators in the tumorigenesis of cholangiocarcinoma (CCA). Previous studies report that miR‐551b‐3p acts as an oncogenic factor in ovarian cancer, but plays a tumour suppressive role in gastric cancer. However, the expression pattern and potential function of miR‐551b‐3p were still unclear in CCA. Therefore, this study aimed to explore the expression of miR‐551b‐3p and its role as well as molecular mechanism in CCA. Analysis of TCGA dataset suggested that miR‐551b‐3p was under‐expressed in CCA tissues compared to normal bile duct tissues. Furthermore, our data confirmed the decreased levels of miR‐551b‐3p in CCA samples and cell lines. Interestingly, TCGA data suggested that low miR‐551b‐3p level indicated reduced overall survival of CCA patients. Gain‐ and loss‐of‐function experiments found that miR‐551b‐3p inhibited the proliferation, G1‐S phase transition and induced apoptosis of CCA cells. In vivo experiments revealed that ectopic expression of miR‐551b‐3p inhibited tumour growth of CCA in mice. Further investigation demonstrated that miR‐551b‐3p directly bond to the 3′‐UTR of Cyclin D1 (CCND1) mRNA and negatively regulated the abundance of CCND1 in CCA cells. An inverse correlation between miR‐551b‐3p expression and the level of CCND1 mRNA was detected in CCA tissues from TCGA dataset. Notably, CCND1 knockdown showed similar effects to miR‐551b‐3p overexpression in HuCCT‐1 cells. CCND1 restoration rescued miR‐551b‐3p‐induced inhibition of proliferation, G1 phase arrest and apoptosis in HuCCT‐1 cells. In summary, miR‐551b‐3p inhibits the expression of CCND1 to suppress CCA cell proliferation and induce apoptosis, which may provide a theoretical basis for improving CCA treatment.

miR-503 expression is downregulated in cervical cancer and suppresses tumor growth by targeting AKT2

Previous studies have reported that microRNAs function as key regulators in tumor development and progression. This study aims to investigate the functional effects of miR-503 expression in cervical cancer (CC) progression. We detected the expression of miR-503 in CC tissues and cell lines using quantitative real-time polymerase chain reaction. Synthesized miR-503 mimics or inhibitors were used to upregulate or downregulate the expression of miR-503 in HeLa or SiHa cells. Cell Counting Kit-8 and colony formation assay were used to detect the ability of cell proliferation. Furthermore, luciferase assay and Western blot were applied to confirm the target of miR-503 in CC cells. Here, we demonstrated that miR-503 expression was significantly downregulated in CC tissues, compared with adjacent normal tissues. miR-503 expression was significantly associated with tumor size and International Federation of Gynecology and Obstetrics stage. Furthermore, increasing miR-503 expression in CC cells dramatically inhibited cell proliferation, colony formation ability of CC. However, reducing miR-503 had reverse effects on these malignant behaviors. Moreover, we demonstrated that miR-503 inhibited cell proliferation by targeting AKT2 3'-untranslated region and affected its expression. Overexpression of AKT2 rescued the effects induced by miR-503 on cell proliferation. Therefore, our results indicated that miR-503 may serve as a tumor suppressor in CC and provide a potential value for CC treatment.

H19X-encoded miR-424(322)/-503 cluster: emerging roles in cell differentiation, proliferation, plasticity and metabolism

miR-424(322)/-503 are mammal-specific members of the extended miR-15/107 microRNA family. They form a co-expression network with the imprinted lncRNA H19 in tetrapods. miR-424(322)/-503 regulate fundamental cellular processes including cell cycle, epithelial-to-mesenchymal transition, hypoxia and other stress response. They control tissue differentiation (cardiomyocyte, skeletal muscle, monocyte) and remodeling (mammary gland involution), and paradoxically participate in tumor initiation and progression. Expression of miR-424(322)/-503 is governed by unique mechanisms involving sex hormones. Here, we summarize current literature and provide a primer for future endeavors.

miR-202 modulates the progression of neuropathic pain through targeting RAP1A

Neuropathic pain is a somatosensory disorder which is caused by disease or nerve injury that affects the nervous system. microRNAs (miRNAs) are proved to play crucial roles in the development of neuropathic pain. However, the role of miR-202 in neuropathic pain is still unknown. Sprague-Dawley rats were used for constructing the neuropathic pain model. The expression of miR-202 was determined by quantitative real-time polymerase chain reaction. Potential target gene for miR-202 was measured using bioinformatics methods and Western blot analysis. In this study, we used rats to establish a neuropathic pain model and measured the effect of miR-202 in neuropathic pain. We demonstrated that miR-202 expression was downregulated in the spinal dorsal horn of bilateral sciatic nerve chronic constriction injury (bCCI) rat. However, miR-202 expression was not changed in the dorsal root ganglion, hippocampus, and anterior cingulated cortex of bCCI rat. We identified that RAP1A was a direct target gene of miR-202 in the PC12 cell. RAP1A expression was upregulated in the spinal dorsal horn of bCCI rat. Overexpression of miR-202 could improve the pain threshold for bCCI rats in both hindpaws, indicating that miR-202 overexpression could lighten the pain threshold for model rats. Moreover, RAP1A overexpression increased the pain threshold effect of miR-202 overexpression treated bCCI rats, indicating that miR-202 could lighten the pain threshold through inhibiting RAP1A expression. These data suggested that miR-202 acted pivotal roles in the development of neuropathic pain partly through targeting RAP1A gene.

The miR-503 cluster is coordinately under-expressed in endometrial endometrioid adenocarcinoma and targets many oncogenes, cell cycle genes, DNA repair genes and chemotherapy response genes

Background

The miR-503 miRNA cluster, located at Xq23.1, is composed of six miRNAs; miR-424, miR-503, miR-542, miR-450a-1, miR-450a-2 and miR-450b. Numerous studies have focused on the relationship of one or two members of the cluster and various human cancers. Here, we suggest that the entire cluster as a single coordinately expressed polycistron transcribed from a single promoter in endometrial endometrioid adenocarcinoma (EEA).

Subjects and methods

A tissue panel composed of twenty histologically confirmed endometrial endometrioid adenocarcinomas (EEA) and four benign endometrium was assembled under informed consent. Expression of each member of the miR-503 cluster was determined by quantitative PCR and differences in expression between EEA and benign tissues were assessed via the standard ΔΔCt method. In addition, the role of promoter methylation status in miRNA expression was examined in Ishikawa H cells following exposure to the cytidine analog Decitabine.

Results

Expression of each member of the miR-503 cluster is significantly downregulated in EEA in our tumor sample. Both in our tumor sample and in The Cancer Genome Atlas (TCGA) there is evidence of highly correlated expression further supporting the idea that the miR-503 cluster is a polycistron. Looking at each member of the miR-503 cluster we were able to identify 55 unique experimentally validated target genes which include a substantial number of genes involved in carcinogenesis, DNA damage response, cell cycle regulation and chemotherapeutic response. We also found preliminary evidence that regulation of the miR-503 cluster is governed by methylation of the promoter in EEA.

Conclusion

The totality of the data presented here strongly suggest that the miR-503 cluster as a whole merits further investigation as an important potential therapeutic target in EEA.

MicroRNA-423 promotes proliferation, migration and invasion and induces chemoresistance of endometrial cancer cells

Altered microRNA expression serves essential roles in tumorigenesis and progression in endometrial cancer. In the present study the effect of miR-423 on proliferation, chemosensitivity, migration and invasion of endometrial cancer cells was examined. A WST-1 assay was used to examine the proliferation of HEC-1B and Ishikawa endometrial cancer cells with either upregulation or downregulation of miR-423, with or without cisplatin treatment. The migration and invasion of HEC-1B and Ishikawa endometrial cancer cells were examined via Transwell migration and Matrigel invasion assays. Protein expression levels, including B cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein, E- and N-cadherin, snail, vimentin, phosphatase and tensin homolog (PTEN) and protein kinase B (AKT) were examined by western blotting. A caspase-Glo3/7 assay was carried out to evaluate the effect of miR-423 on cisplatin-induced apoptosis in HEC-1B and Ishikawa endometrial cancer cells. Overexpression of miR-423 enhanced the proliferation, and increased migration and invasion in endometrial cancer cells. miR-423 also decreased the sensitivity of endometrial cancer cells following cisplatin treatment. miR-423 inhibited cisplatin-induced apoptosis in endometrial cancer cells by regulation of caspase 3/7 and Bcl-2 expression. Furthermore, the E-cadherin expression was significantly decreased, and the expression of N-cadherin, snail and Vimentin were increased in both HEC-1B cells and Ishikawa cells following overexpression of miR-423. Conversely, downregulation of miR-423 increased the expression of E-cadherin and decreased the expression of N-cadherin, snail and Vimentin. Further experiments demonstrated that the expression levels of PTEN and phosphorylated-AKT in HEC-1B and Ishikawa endometrial cancer cells was decreased and increased, respectively, following aberrant expression of miR-423. miR-423 displayed an important role in tumorigenesis and progression in endometrial cancer cells, and may therefore be used as a potential biomarker to predict chemotherapy response and prognosis in endometrial cancer.

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.

miR‑29a‑3p represses proliferation and metastasis of gastric cancer cells via attenuating HAS3 levels

MicroRNA-29a (miR-29a) has recently been in the spotlight as a tumor suppressor whose encoding gene is frequently suppressed in cancers. The aim of the present study was to investigate the biological functions and underlying molecular mechanism by which miR-29a-3p suppresses gastric cancer peritoneum metastasis. Cell proliferation, colony-forming, wound healing and Transwell migration assays were performed in the present study. MiR-29a-3p expression was markedly decreased in gastric cancer cell lines with stronger metastatic potential. Silencing miR-29a-3p expression promoted gastric cancer cell proliferation, colony-forming, migration and invasion. By contrast, overexpression of miR-29a-3p inhibited these biological phenotypes. In addition, it was revealed that miR-29a-3p functioned through downregulating hyaluronan synthase 3 expression. Collectively, dysregulated miR-29a-3p expression in gastric cancer cells was associated with malignant properties primarily relevant to migration and metastasis. The results suggest that miR-29a-3p may be a potential therapeutic target for gastric cancer.

miR-503 suppresses the proliferation and metastasis of esophageal squamous cell carcinoma by triggering autophagy via PKA/mTOR signaling

MicroRNA (miR)-503 is involved in the regulation of the malignant phenotype in multiple tumor types, and has been proven to be a novel diagnostic and therapeutic target; however, its function and mechanisms of action have not yet been fully elucidated in esophageal squamous cell carcinoma (ESCC). In the current study, we detected miR‑503 expression by RT‑qPCR and found that miR‑503 expression was increased in ESCC, but negatively correlated with lymph node metastasis, TNM stage and tumor differentiation. Functionally, we confirmed that miR‑503 inhibited the proliferation and metastasis of ESCC cells by triggering cellular autophagy. Mechanistically, we confirmed that miR‑503 exerted its biological effects by targeting protein kinase CAMP‑activated catalytic subunit alpha (PRKACA) in ESCC by dual luciferase reporter assay. Moreover, miR‑503 was found to trigger autophagy in ESCC cells through the protein kinase A (PKA)/mammalian target of rapamycin (mTOR) pathway. Taken together, our results demonstrate that miR‑503 suppresses the proliferation and metastasis of ESCC via the activation of autophagy, mediated by the PKA/mTOR signaling pathway.

microRNA involvement in the onset and progression of Barrett's esophagus: a systematic review

Esophageal adenocarcinoma (EAC) is a highly aggressive malignancy that develops from Barrett's esophagus (BE), an intestinal metaplasia of the distal esophagus. microRNAs (miRNAs), short non-coding regulatory RNAs, are frequently dysregulated in BE and are thought to play key roles in the onset of BE and its progression to EAC. miRNAs thus have potential diagnostic and prognostic value and are increasingly being used as cancer biomarkers. This review summarizes the current literature related to miRNAs that are dysregulated in BE within the context of Hedgehog, Notch, MAPK, NF kappa-B, Wnt and epithelial-mesenchymal transition (EMT) signaling which are thought to drive BE onset and progression. This comprehensive analysis of miRNAs and their associated signaling in the regulation of BE provides an overview of vital discoveries in this field and highlights gaps in our understanding of BE pathophysiology that warrant further investigation.

MicroRNAs in parathyroid physiopathology

Parathyroid glands regulate calcium homeostasis through synthesis and secretion of parathormone (PTH). They sense the extracellular calcium concentration through the G-protein coupled calcium sensing receptor (CASR) and release PTH in order to preserve calcium concentration in the physiological range. Tumors of the parathyroid glands are common endocrine neoplasia associated with primary or secondary/tertiary hyperparathyroidisms. Small non-coding RNAs are regulators of gene expression able to modulate hormone synthesis, hormone release and endocrine cell proliferation. In this scenario, microRNA (miRNA) expression profiles have been investigated in parathyroid tumors, while miRNAs are involved in hypocalcemia and uremia-induced PTH release from normal parathyroid cells. Here we reviewed data about the role of miRNAs in the regulation of: 1) PTH synthesis and secretion; 2) CASR expression; 3) parathyroid cell tumorigenesis. Though studies about miRNAs in parathyroid gland pathophysiology are limited, they contribute in elucidating regulatory pathways involved in PTH release and parathyroid cell tumorigenesis.

MicroRNA‑503 serves an oncogenic role in laryngeal squamous cell carcinoma via targeting programmed cell death protein 4

Laryngeal squamous cell carcinoma (LSCC), the most common form of laryngeal carcinoma, is an aggressive malignancy that demonstrates the second highest rate of morbidity of all head and neck squamous cell carcinomas. The abnormal expression of microRNAs (miRs) has been demonstrated in a number of types of human cancer, and they have been demonstrated to be oncogenes or tumour suppressor genes. miR-503 has been studied in various types of human cancer; however, the expression level, roles and underlying mechanisms in LSCC remain unknown. In the present study, it was demonstrated that miR-503 was significantly upregulated in LSCC tissues and cell lines. The level of miR-503 in LSCC tissues was correlated with thyroid cartilage invasion, lymph node metastasis, and tumour, node and metastasis stage. In addition, down-regulation of miR-503 inhibited cell proliferation and invasion in LSCC. Programmed cell death protein 4 (PDCD4) was identified to be a direct target gene of miR-503. PDCD4 overexpression could mimic the roles of miR-503 underexpression in LSCC. Furthermore, PDCD4 was down-regulated in LSCC tissues and this correlated with the miR-503 expression level. In conclusion, these results suggested that miR-503 promotes tumour growth and invasion by directly targeting PDCD4. The identification of the miR-503/PDCD4 axis may provide novel targets for LSCC treatment and improve prognosis.

FARNA: knowledgebase of inferred functions of non-coding RNA transcripts

Non-coding RNA (ncRNA) genes play a major role in control of heterogeneous cellular behavior. Yet, their functions are largely uncharacterized. Current available databases lack in-depth information of ncRNA functions across spectrum of various cells/tissues. Here, we present FARNA, a knowledgebase of inferred functions of 10,289 human ncRNA transcripts (2,734 microRNA and 7,555 long ncRNA) in 119 tissues and 177 primary cells of human. Since transcription factors (TFs) and TF co-factors (TcoFs) are crucial components of regulatory machinery for activation of gene transcription, cellular processes and diseases in which TFs and TcoFs are involved suggest functions of the transcripts they regulate. In FARNA, functions of a transcript are inferred from TFs and TcoFs whose genes co-express with the transcript controlled by these TFs and TcoFs in a considered cell/tissue. Transcripts were annotated using statistically enriched GO terms, pathways and diseases across cells/tissues based on guilt-by-association principle. Expression profiles across cells/tissues based on Cap Analysis of Gene Expression (CAGE) are provided. FARNA, having the most comprehensive function annotation of considered ncRNAs across widest spectrum of human cells/tissues, has a potential to greatly contribute to our understanding of ncRNA roles and their regulatory mechanisms in human. FARNA can be accessed at: http://cbrc.kaust.edu.sa/farna

Downregulation of miR-503 Promotes ESCC Cell Proliferation, Migration, and Invasion by Targeting Cyclin D1

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive cancers in China, but the underlying molecular mechanism of ESCC is still unclear. Involvement of microRNAs has been demonstrated in cancer initiation and progression. Despite the reported function of miR-503 in several human cancers, its detailed anti-oncogenic role and clinical significance in ESCC remain undefined. In this study, we examined miR-503 expression by qPCR and found the downregulation of miR-503 expression in ESCC tissue relative to adjacent normal tissues. Further investigation in the effect of miR-503 on ESCC cell proliferation, migration, and invasion showed that enhanced expression of miR-503 inhibited ESCC aggressive phenotype and overexpression of CCND1 reversed the effect of miR-503-mediated ESCC cell aggressive phenotype. Our study further identified CCND1 as the target gene of miR-503. Thus, miR-503 functions as a tumor suppressor and has an important role in ESCC by targeting CCND1.

Exploration of miR-1202 and miR-196a in human endometrial cancer based on high throughout gene screening analysis

Altered microRNA (miRNA) expression has been reported to participate in the pathogenesis of several human diseases, and particularly cancer. The present study examined the involvement of various miRNAs in the pathophysiology of endometrial cancer (EC) and atypical endometrial hyperplasia (AEH). We performed a high-throughput analysis of the miRNAs (miRNA microarray) found in samples of endometrial tissue obtained from 45 patients; among whom, 15 patients were diagnosed with EC, 15 patients were diagnosed with AEH, and the remainder were healthy donors. Next, we selected several miRNAs which exhibited at least a 2-fold difference in expression with a P<0.05 to validate these changes in 3 independent in vitro experiments that used real-time PCR analysis. Finally, miR-1202 and miR-196a were selected as target molecules whose effects on cell apoptosis, cell cycle changes, cell migratory and invasive abilities were investigated using flow cytometric and Transwell assays, respectively, after pre-treatment in vitro. After analyzing 125 miRNAs in a microarray assay, 6 miRNAs (3-high and 3-low expression) were further evaluated via paired comparison in all 3 groups. The validation test revealed a positive correlation between the microarray results and a high level of miR-1202 and a low level of miR-196a in the EC group, when compared with the AEH group. All of the data were normalized with data obtained from normal control donors. We found that either miR-1202 silencing or miR-196a overexpression affected AN3CA and HEC-1-A cells by increasing their apoptosis level and inducing G1 phase arrest while decreasing their migratory and invasive abilities. Inhibitors of miR-1202 and mimics of miR‑196a may exert a protective effect, suggesting that miR-1202 and miR‑196a may serve as biomarkers for evaluating the effectiveness of EC treatment.

miR-424(322)/503 is a breast cancer tumor suppressor whose loss promotes resistance to chemotherapy

In this study, Rodriguez-Barrueco et al. analyzed ∼3000 primary tumors and show that miR-424(322)/503 is commonly lost in a subset of aggressive breast cancers; they then describe the genetic aberrations that inactivate its expression. Their data show that miR-424(322)/503 is a tumor suppressor in breast cancer and provide a link between mammary epithelial involution, tumorigenesis, and the phenomenon of chemoresistance.

The female mammary gland is a very dynamic organ that undergoes continuous tissue remodeling during adulthood. Although it is well established that the number of menstrual cycles and pregnancy (in this case transiently) increase the risk of breast cancer, the reasons are unclear. Growing clinical and experimental evidence indicates that improper involution plays a role in the development of this malignancy. Recently, we described the miR-424(322)/503 cluster as an important regulator of mammary epithelial involution after pregnancy. Here, through the analysis of ∼3000 primary tumors, we show that miR-424(322)/503 is commonly lost in a subset of aggressive breast cancers and describe the genetic aberrations that inactivate its expression. Furthermore, through the use of a knockout mouse model, we demonstrate for the first time that loss of miR-424(322)/503 promotes breast tumorigenesis in vivo. Remarkably, we found that loss of miR-424(322)/503 promotes chemoresistance due to the up-regulation of two of its targets: BCL-2 and insulin-like growth factor-1 receptor (IGF1R). Importantly, targeted therapies blocking the aberrant activity of these targets restore sensitivity to chemotherapy. Overall, our studies reveal miR-424(322)/503 as a tumor suppressor in breast cancer and provide a link between mammary epithelial involution, tumorigenesis, and the phenomenon of chemoresistance.

Differential regulated microRNA by wild type and mutant p53 in induced pluripotent stem cells

The tumour suppressor p53 plays an important role in somatic cell reprogramming. While wild-type p53 reduces reprogramming efficiency, mutant p53 exerts a gain of function activity that leads to increased reprogramming efficiency. Furthermore, induced pluripotent stem cells expressing mutant p53 lose their pluripotency in vivo and form malignant tumours when injected in mice. It is therefore of great interest to identify targets of p53 (wild type and mutant) that are responsible for this phenotype during reprogramming, as these could be exploited for therapeutic use, that is, formation of induced pluripotent stem cells with high reprogramming efficiency, but no oncogenic potential. Here we studied the transcriptional changes of microRNA in a series of mouse embryonic fibroblasts that have undergone transition to induced pluripotent stem cells with wild type, knock out or mutant p53 status in order to identify microRNAs whose expression during reprogramming is dependent on p53. We identified a number of microRNAs, with known functions in differentiation and carcinogenesis, the expression of which was dependent on the p53 status of the cells. Furthermore, we detected several uncharacterised microRNAs that were regulated differentially in the different p53 backgrounds, suggesting a novel role of these microRNAs in reprogramming and pluripotency.

miR-503 inhibits proliferation making human hepatocellular carcinoma cells susceptible to 5‑fluorouracil by targeting EIF4E

Hepatocellular carcinoma (HCC), a disease that is a major health care issue across the globe, includes the deviant expression of miRNAs in its development, progression, and resistance to treatment. We focused our study on miR‑503 expression and its role in HCC. miR‑503 was found in HCC tissues and cell lines using quantitative real-time PCR (RT‑qPCR). Western blot analyses and the luciferase reporter assay were used to determine the miR‑503 potential target in the HCC cells. We used MTT to analyze cell proliferation activity and noted that there was a considerable decrease of miR‑503 in HCC tissues and cell lines when measured against the controls. miR‑503 upregulation decreased expression of eukaryotic translation initiation factor 4E (EIF4E), and reduced HCC cell proliferation and sensitized HCC cells to anticancer drugs. miR‑503 overexpression hindered luciferase activity of EIF4E 3' untranslated region-based reporter construct among HepG2, BEL-7402, and SMMC-7721 cells, revealing that miR‑503 may increase sensitivity to therapies at least partially through targeting EIF4E suppression of HCC proliferation.

miR-503, a microRNA epigenetically repressed in endometriosis, induces apoptosis and cell-cycle arrest and inhibits cell proliferation, angiogenesis, and contractility of human ovarian endometriotic stromal cells

STUDY QUESTION

Is the micro-RNA (miRNA) miR-503, downregulated in endometriotic cyst stromal cells (ECSCs) and does this affect the cell cycle, cell proliferation, angiogenesis and contractility of these cells? SUMMARY ANSWER: miR-503 expression is downregulated in ECSCs by DNA hypermethylation and this contributes to their proliferation, resistance to apoptosis, extracellular matrix (ECM) contractility and angiogenesis through effects on cyclin D1, B-cell lymphoma/leukemia (Bcl)-2, Ras homology A  and vascular endothelial growth factor A (VEGF-A).

WHAT IS KNOWN ALREADY

A variety of miRNAs are demonstrated to involve in the pathogenesis of endometriosis. miR-503 is a miRNA with tumor-suppressor functions, whose expression is suppressed in ECSCs.

STUDY DESIGN, SIZE, DURATION

We isolated ECSCs and normal endometrial stromal cells (NESCs) from ovarian endometriotic tissues (n = 32) and eutopic endometrial tissues without endometriosis (n = 8), respectively.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We investigated the functions of miR-503 by using miR-503-transfected ECSCs and the DNA methylation status of miR-503 gene in ECSCs and NESCs by combined bisulfite restriction analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

In ECSCs, miR-503 is downregulated by the DNA hypermethylation of its gene. The transfection of miR-503 into ECSCs resulted in the inhibition of cell proliferation and induction of cell-cycle arrest at G0/G1 phase through the suppression of cyclin D1, the induction of apoptosis through Bcl-2 suppression, the inhibition of VEGF-A production and the attenuation of ECM contractility via the suppression of Rho/Rho-associated coiled-coil-forming protein kinase-pathways.

LARGE SCALE DATA

NA.

LIMITATIONS, REASONS FOR CAUTION

The present experiments were carried out only with the stromal component of endometriosis and eutopic endometrium. The experiments with the eutopic endometrial stromal cells from women with endometriosis are not performed.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings indicate that epigenetically repressed miR-503 in ECSCs is involved in the acquisition of endometriosis-specific cellular functions.

STUDY FUNDING/COMPETING INTERESTS

This work was supported in part by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (no. 13237327 to K.N., no. 26861335 to K.K. and no. 23592407 to H.N.) and the Kanzawa Medical Research Foundation (to K.K.). There are no conflicts of interest to declare.

miR-322/-503 cluster is expressed in the earliest cardiac progenitor cells and drives cardiomyocyte specification

Understanding the mechanisms of early cardiac fate determination may lead to better approaches in promoting heart regeneration. We used a mesoderm posterior 1 (Mesp1)-Cre/Rosa26-EYFP reporter system to identify microRNAs (miRNAs) enriched in early cardiac progenitor cells. Most of these miRNA genes bear MESP1-binding sites and active histone signatures. In a calcium transient-based screening assay, we identified miRNAs that may promote the cardiomyocyte program. An X-chromosome miRNA cluster, miR-322/-503, is the most enriched in the Mesp1 lineage and is the most potent in the screening assay. It is specifically expressed in the looping heart. Ectopic miR-322/-503 mimicking the endogenous temporal patterns specifically drives a cardiomyocyte program while inhibiting neural lineages, likely by targeting the RNA-binding protein CUG-binding protein Elav-like family member 1 (Celf1). Thus, early miRNAs in lineage-committed cells may play powerful roles in cell-fate determination by cross-suppressing other lineages. miRNAs identified in this study, especially miR-322/-503, are potent regulators of early cardiac fate.

Effect of differentiation on microRNA expression in bovine skeletal muscle satellite cells by deep sequencing

Background

The differentiation of skeletal muscle-derived satellite cells (MDSCs) is important in controlling muscle growth, improving livestock muscle quality, and healing of muscle-related disease. MicroRNAs (miRNAs) are a class of gene expression regulatory factors, which play critical roles in the regulation of muscle cell differentiation. This study aimed to compare the expression profile of miRNAs in MDSC differentiation, and to investigate the miRNAs which are involved in MDSC differentiation.

Method

Total RNA was extracted from MDSCs at three different stages of differentiation (MDSC-P, MDSC-D1 and MDSC-D3, representing 0, 1 and 3 days after differentiation, respectively), and used to construct small RNA libraries for RNA sequencing (RNA-seq).

Results

The results showed that in total 617 miRNAs, including 53 novel miRNA candidates, were identified. There were 9 up-expressed, 165 down-expressed, and 15 up-expressed, 145 down-expressed in MDSC-D1 and MDSC-D3, respectively, compared to those in MDSC-P. Also, 17 up-expressed, 55 down-expressed miRNAs were observed in MDSC-D3 compared to those in MDSC-D1. All known miRNAs belong to 237 miRNA gene families. Furthermore, we observed some sequence variants and base edits of the miRNAs. GO and KEGG pathway analysis showed that the majority of target genes regulated by miRNAs were involved in cellular metabolism, pathways in cancer, actin cytoskeleton regulation and the MAPK signaling pathway. Regarding the 53 novel miRNAs, there were 7 up-expressed, 31 down-expressed, and 8 up-expressed, 26 down-expressed in MDSC-D1 and MDSC-D3, respectively, compared to those in MDSC-P. The expression levels of 12 selected miRNA genes detected by RT-qPCR were consistent with those generated by deep sequencing.

Conclusions

This study confirmed the authenticity of 564 known miRNAs and identified 53 novel miRNAs which were involved in MDSC differentiation. The identification of novel miRNAs has significantly expanded the repertoire of bovine miRNAs and could contribute to advances in understanding muscle development in cattle.

Electronic supplementary material

The online version of this article (doi:10.1186/s11658-016-0009-x) contains supplementary material, which is available to authorized users.

A Multi-Step miRNA-mRNA Regulatory Network Construction Approach Identifies Gene Signatures Associated with Endometrioid Endometrial Carcinoma

We aimed to identify endometrioid endometrial carcinoma (EEC)-related gene signatures using a multi-step miRNA-mRNA regulatory network construction approach. Pathway analysis showed that 61 genes were enriched on many carcinoma-related pathways. Among the 14 highest scoring gene signatures, six genes had been previously shown to be endometrial carcinoma. By qRT-PCR and next generation sequencing, we found that a gene signature (CPEB1) was significantly down-regulated in EEC tissues, which may be caused by hsa-miR-183-5p up-regulation. In addition, our literature surveys suggested that CPEB1 may play an important role in EEC pathogenesis by regulating the EMT/p53 pathway. The miRNA-mRNA network is worthy of further investigation with respect to the regulatory mechanisms of miRNAs in EEC. CPEB1 appeared to be a tumor suppressor in EEC. Our results provided valuable guidance for the functional study at the cellular level, as well as the EEC mouse models.

miRNA-503 Promotes Tumor Progression and Is Associated with Early Recurrence and Poor Prognosis in Human Colorectal Cancer

OBJECTIVES

MicroRNA (miR)-503 is downregulated in several cancers and plays a tumor-suppressive role in carcinogenesis. However, the miR-503 expression pattern, its clinical significance and its molecular mechanism in colorectal cancer (CRC) have not been investigated.

METHODS

We analyzed miR-503 expression in normal mucosa (n = 20), adenoma (n = 27) and CRC (n = 20). We quantified miR-503 expression in an independent cohort (n = 191) and investigated the clinical significance of miR-503 in CRC. CRC cell lines were transfected with anti-miR-503 to assess its function and target gene.

RESULTS

miR-503 expression increased according to the adenoma-carcinoma sequence. High miR-503 expression was significantly associated with large tumor size, serosal invasion, lymphatic and venous invasion as well as lymph node metastasis. CRC patients with high miR-503 expression had significantly earlier relapse and poorer prognosis than those with low expression. miR-503 was an independent recurrence marker in stage I/II CRC. In vitro, attenuated miR-503 expression resulted in inhibition of proliferation, invasion and migration and acquisition of anoikis of CRC cells. The putative target gene (calcium-sensing receptor) was significantly upregulated after miR-503 attenuation.

CONCLUSIONS

miR-503 acts as an 'onco-miR' in CRC. High miR-503 expression is associated with early recurrence and poor prognosis in CRC.

Increased expression of microRNA-503 and reduced expression of kangai-1 in B-cell non-Hodgkin's lymphoma

The aim of the present study was to determine the expression levels of microRNA-503 (miR-503) and the tumor suppressor gene, kangai-1 (KAI1), in B-cell non-Hodgkin's lymphoma (B-NHL). A total of 45 patients with B-NHL (including 29 cases with stage III/IV disease and 16 cases with stage I/II disease) were enrolled in this study. In addition, 26 patients with reactive lymphoid hyperplasia (RLH) were enrolled as the control patients. Reverse transcription-quantitative polymerase chain reaction was performed in order to measure the expression levels of miR-503 in B-NHL and RLH tissues, and to detect the expression levels of miR-503 and KAI1 in peripheral blood samples. In addition, KAI1 expression levels in B-NHL and RLH tissues were detected using western blotting and immunohistochemical analysis. The expression levels of miR-503 were found to be significantly increased in the tissues and peripheral blood of B-NHL patients when compared with those in RLH patients (P<0.05). However, KAI1 was strongly expressed in RLH tissues and weakly expressed in B-NHL tissues. Furthermore, the expression levels of KAI1 were significantly decreased in the tissues and peripheral blood of B-NHL patients when compared with those in the tissues and peripheral blood of RLH patients (P<0.05). The expression levels of miR-503 in the tissues and peripheral blood of patients with stage III/IV B-NHL were significantly higher compared with those with stage I/II B-NHL (P<0.05). By contrast, the expression levels of KAI1 in stage III/IV B-NHL tissues were significantly higher compared with those in stage I/II B-NHL tissues (P<0.05). In conclusion, miR-503 was highly expressed, whereas KAI1 was poorly expressed, in the tissues and peripheral blood of B-NHL patients. Thus, miR-503 may have an application as a novel therapeutic and diagnostic marker in B-NHL patients.

Role of microRNA‑503 in the suppression of osteosarcoma cell proliferation and migration via modulation of fibroblast growth factor 2

The present study aimed to investigate the expression levels of microRNA (miR)‑503 in osteosarcoma (OS), as well as to assess the effects and underlying mechanisms of miR‑503 on cell proliferation, apoptosis, migration and invasion of OS cells. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to determine the expression levels of miR‑503 in OS and adjacent normal bone tissue samples. Proliferation, apoptosis, migration and invasion assays were performed to determine the effects of miR‑503 on OS cells. The expression levels of miR‑503 were significantly decreased in OS tissue samples, as compared with normal tissue samples (P<0.0001). Upregulation of miR‑503 significantly inhibited proliferation and induced cell apoptosis, as compared with the negative controls. The results of the present study also demonstrated that miR‑503 significantly decreased the migration and invasion ability of the OS cells, which may be mediated by the inhibition of fibroblast growth factor 2 (FGF2). In conclusion, the present study demonstrated that expression of miR-503 was involved in the inhibition of cellular proliferation, and induced apoptosis of the OS cells. In addition, miR‑503 was able to inhibit the migration and invasion ability of OS cells, likely via the inhibition of FGF2 expression.

miR-503 suppresses metastasis of hepatocellular carcinoma cell by targeting PRMT1

Accumulating evidence indicates that microRNAs function as oncogenes or tumor suppressor genes in human cancer. MiR-503 is deregulated in various human cancers and has been associated with hepatocellular carcinoma (HCC) progression. However, the underlying mechanisms of miR-503 involvement in the development and progression of HCC remains poorly understood. In the present study, we report that miR-503 suppresses cell metastasis in HCC through targeting the protein arginine methyl transferase 1 (PRMT1) mRNA. Notably, we identified that miR-503 was able to target 3'-untranslated region (3'-UTR) of PRMT1 mRNA by luciferase reporter gene assays. Then, we revealed that miR-503 was able to reduce the expression of PRMT1 at the levels of mRNA and protein using RT-PCR and Western blotting analysis. The expression levels of miR-503 were negatively related to those of PRMT1 mRNA in clinical HCC tissues. In terms of function, transwell and wound healing assays demonstrated that the miR-503 remarkably inhibited invasion and migration of HCC cells, which was reversed by overexpressed PRMT1. Furthermore, exogenous expression of miR-503 dramatically suppressed epithelial-mesenchymal transition (EMT) via PRMT1 in HCC cells. In conclusion, we denomstrated PRMT1 as a novel target gene of miR-503 and miR-503-mediated PRMT1 could also emerge as a potential important biomarker for HCC.

Impact of Nutrition on Non-Coding RNA Epigenetics in Breast and Gynecological Cancer

Cancer is the second leading cause of death in females. According to the American Cancer Society, there are 327,660 new cases in breast and gynecological cancers estimated in 2014, placing emphasis on the need for cancer prevention and new cancer treatment strategies. One important approach to cancer prevention involves phytochemicals, biologically active compounds derived from plants. A variety of studies on the impact of dietary compounds found in cruciferous vegetables, green tea, and spices like curry and black pepper have revealed epigenetic changes in female cancers. Thus, an important emerging topic comprises epigenetic changes due to the modulation of non-coding RNA levels. Since it has been shown that non-coding RNAs such as microRNAs and long non-coding RNAs are aberrantly expressed in cancer, and furthermore are linked to distinct cancer phenotypes, understanding the effects of dietary compounds and supplements on the epigenetic modulator non-coding RNA is of great interest. This article reviews the current findings on nutrition-induced changes in breast and gynecological cancers at the non-coding RNA level.

MicroRNAs in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a devastating disease without effective treatment. Despite decades of research and the development of novel treatments, PAH remains a fatal disease, suggesting an urgent need for better understanding of the pathogenesis of PAH. Recent studies suggest that microRNAs (miRNAs) are dysregulated in patients with PAH and in experimental pulmonary hypertension. Furthermore, normalization of a few miRNAs is reported to inhibit experimental pulmonary hypertension. We have reviewed the current knowledge about miRNA biogenesis, miRNA expression pattern, and their roles in regulation of pulmonary artery smooth muscle cells, endothelial cells, and fibroblasts. We have also identified emerging trends in our understanding of the role of miRNAs in the pathogenesis of PAH and propose future studies that might lead to novel therapeutic strategies for the treatment of PAH.

Microparticles in cancer: A review of recent developments and the potential for clinical application

Once thought of as inert remnants of cellular processes, the significance of membrane vesicles is now expanding as their capacity to package and transfer bioactive molecules during intercellular communication is established. This ability to serve as vectors in the trafficking of cellular cargo is of mounting interest in the context of cancer, particularly in the dissemination of deleterious cancer traits from donor cells to recipient cells. Although microparticles (MPs) contribute to the pathogenesis of cancer, their unique characteristics can also be exploited in the context of cancer management. The detection of MPs in body fluids has the potential to provide an effective means for the diagnosis, prognosis and surveillance of cancer patients. The use of these readily accessible systemic biomarkers has the potential to circumvent the need for invasive biopsy procedures. In addition, the autologous nature of MPs may allow them to be used as novel drug delivery carriers. Consequently, the modulation of MP vesiculation to treat disease, the detection of MPs in disease monitoring, and the application of MPs as therapeutic delivery vehicles present prospective clinical interventions in the treatment of cancer.