microRNA-450a targets DNA methyltransferase 3a in hepatocellular carcinoma

miR-450b promotes cell migration and invasion by inhibiting SERPINB2 in oral squamous cell carcinoma

OBJECTIVE

microRNA-450b (miR-450b) plays an important role in cancer progression; however, its function in oral squamous cell carcinoma (OSCC) remains largely unknown. This study aimed to investigate the action mechanisms of miR-450b in OSCC.

MATERIALS AND METHODS

OSCC animal model was established via continuous induction with single-drug 7, 12-dimethylbenzo[a]anthracene (DMBA). Animal tissue samples were pathologically typed using haematoxylin-eosin (HE) staining. The Cancer Genome Atlas (TCGA) database was used to predict miR-450b and SERPINB2 expression in head and neck squamous cell carcinoma (HNSCC). qRT-PCR and Western blotting were used to detect gene and protein expression in OSCC tissue and cells, respectively. OSCC cell proliferation, growth, migration and invasion were detected using CCK-8, colony formation, transwell migration and matrigel invasion assays, respectively. Bioinformatic tools were used to predict miR-450b target genes. Dual-luciferase reporter assay was used to verify targeting between miR-450b and SERPINB2. Finally, small interfering RNA (siRNA) was used to reduce SERPINB2 expression to detect its effect on tumourigenesis.

RESULTS

Four stages of OSCC carcinogenesis (normal oral epithelium, simple epithelial hyperplasia, dysplasia and OSCC) were identified. miR-450b was found to be overexpressed in OSCC animal samples, HNSCC samples and human OSCC cells. Upregulation of miR-450b significantly promoted OSCC cell proliferation, colony formation, migration and invasion, while its downregulation had the opposite effect. SERPINB2 was found to be a miR-450b target gene, and its expression was negatively correlated with miR-450b expression. Altering SERPINB2 expression effectively inhibited OSCC cell invasion, metastasis and epithelial-mesenchymal transition (EMT).

CONCLUSIONS

miR-450b plays a key role in OSCC tumourigenesis by regulating OSCC cell migration, invasion and EMT via SERPINB2.

Emerging role of MicroRNA-Based theranostics in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC), with its high mortality and short survival rate, continues to be one of the deadliest malignancies despite relentless efforts and several technological advances. The poor prognosis of HCC and the few available treatments are to blame for the low survival rate, which emphasizes the importance of creating new, effective diagnostic markers and innovative therapy strategies. In-depth research is being done on the potent biomarker miRNAs, a special class of non-coding RNA and has shown encouraging results in the early identification and treatment of HCC in order to find more viable and successful therapeutics for the disease. It is beyond dispute that miRNAs control cell differentiation, proliferation, and survival and, depending on the genes they target, can either promote tumorigenesis or suppress it. Given the vital role miRNAs play in the biological system and their potential to serve as ground-breaking treatments for HCC, more study is required to fully examine their theranostic potential.

miR-450a exerts oncosuppressive effects in breast carcinoma by targeting CREB1

Emerging evidence greatly implicates that microRNA-450a (miR-450a) plays an essential role in cancer pathobiology. While the pathological role of miR-450a in breast carcinogenesis remains enigmatic. Herein, we showed that miR-450a was lowly expressed in breast cancer cell lines compared with normal, and low miR-450a expression was associated with poor survival in patients with breast cancer. We revealed that miR-450a mimic transfected breast cancer cells (T47D and BT474) exhibited attenuated capacities of proliferation, migration, and invasion in vitro, and miR-450a suppressed T47D cell growth in a xenograft tumor model. Mechanistically, cAMP response element-binding protein 1 (CREB1) was negatively targeted by miR-450a, and CREB1 deletion mimicked the effects of miR-450a mimic treatment. Bioinformatics analysis further revealed that elevated expression of CREB1 correlated with poor prognosis in patients with breast cancer and miR-450a level was negatively correlated with CREB1 level in breast cancer. Additionally, miR-450a inhibited the phosphorylation of phosphatidylinositol 3-kinase/V-akt murine thymoma viral oncogene homolog (PI3K/AKT) and the activities of matrix metalloproteinase-2/9 (MMP-2/9). The following rescue assay indicated that CREB1 was implicated in the anti-tumoral effect of mR-450a in breast carcinoma. All these observations disclosed that miR-450a negatively regulates the growth and metastatic property of breast carcinoma cells.

MicroRNAs in the Pathogenesis of Hepatocellular Carcinoma: A Review

Simple Summary

Hepatocellular carcinoma (HCC) is one of the most frequently occurring cancers, and the prognosis for late-stage HCC remains poor. A better understanding of the pathogenesis of HCC is expected to improve outcomes. MicroRNAs (miRNAs) are small, noncoding, single-stranded RNAs that regulate the expression of various target genes, including those in cancer-associated genomic regions or fragile sites in various human cancers. We summarize the central roles of miRNAs in the pathogenesis of HCC and discuss their potential utility as valuable biomarkers and new therapeutic agents for HCC.

Abstract

Hepatocellular carcinoma (HCC) is the seventh most frequent cancer and the fourth leading cause of cancer mortality worldwide. Despite substantial advances in therapeutic strategies, the prognosis of late-stage HCC remains dismal because of the high recurrence rate. A better understanding of the etiology of HCC is therefore necessary to improve outcomes. MicroRNAs (miRNAs) are small, endogenous, noncoding, single-stranded RNAs that modulate the expression of their target genes at the posttranscriptional and translational levels. Aberrant expression of miRNAs has frequently been detected in cancer-associated genomic regions or fragile sites in various human cancers and has been observed in both HCC cells and tissues. The precise patterns of aberrant miRNA expression differ depending on disease etiology, including various causes of hepatocarcinogenesis, such as viral hepatitis, alcoholic liver disease, or nonalcoholic steatohepatitis. However, little is known about the underlying mechanisms and the association of miRNAs with the pathogenesis of HCC of various etiologies. In the present review, we summarize the key mechanisms of miRNAs in the pathogenesis of HCC and emphasize their potential utility as valuable diagnostic and prognostic biomarkers, as well as innovative therapeutic targets, in HCC diagnosis and treatment.

Lactobacillus Plantarum 299v Changes miRNA Expression in the Intestines of Piglets and Leads to Downregulation of LITAF by Regulating ssc-miR-450a

Lactiplantibacillus plantarum subsp. plantarum 299v (L. plantarum 299v) is one of the most important probiotic strains in animal health, but the molecular mechanisms of how it exerts health benefits remain unclear. The purpose of this study was to explore the changes in miRNA expression profiles in the intestinal tissues of piglets by L. plantarum 299v and to explore its possible molecular regulatory mechanism in intestinal function. Neonatal piglets were orally administered L. plantarum 299v daily from 1 to 20 days old, and high-throughput sequencing was conducted to analyse the changes in miRNA expression in the jejunum and ileum. The results showed that 370 known porcine miRNAs were identified from eight libraries. Five miRNAs (ssc-miR-21-5p, -143-3p, -194b-5p, -192, and -126-3p) were highly expressed in the intestinal tissues. There were 15 differentially expressed miRNAs between the control group and the L. plantarum group, and only miR-450a was expressed differentially in both intestinal tissues. KEGG analysis revealed that the target genes of the 15 differentially expressed miRNAs were involved in 37 significantly enriched pathways (P < 0.01). Then, quantitative polymerase chain reaction confirmed that the miRNA expression was corresponded well with those from the sequencing. Luciferase reporter assays verified that lipopolysaccharide-induced TNF-α factor is a target of miR-450a. Our results also showed L. plantarum 299v could influence intestinal function by changing the levels of cytokines via miRNA expression. This is the first study to analyse differential expression miRNA profiles in intestinal tissue after L. plantarum 299v treatment and investigate the molecular regulatory mechanism of functional miRNA.

Insight in miRNome of Long-Term Non-Progressors and Elite Controllers Exposes Potential RNAi Role in Restraining HIV-1 Infection

Long-term non-progressors (LTNP) and elite controllers (EC) represent spontaneous natural models of efficient HIV-1 response in the absence of treatment. The main purposes of this work are to describe the miRNome of HIV-1 infected patients with different extreme phenotypes and identify potentially altered pathways regulated by differentially expressed (DE) miRNAs. The miRNomes from peripheral blood mononuclear cells (PBMCs) of dual phenotype EC-LTNP or LTNP with detectable viremia and HIV-infected patients with typical progression before and after treatment, were obtained through miRNA-Seq and compared among them. The administration of treatment produces 18 DE miRNAs in typical progressors. LTNP condition shows 14 DE miRNA when compared to typical progressors, allowing LTNP phenotype differentiation. A set of four miRNAs: miR-144-3p, miR-18a-5p, miR-451a, and miR-324 is strongly downregulated in LTNP and related to protein regulation as AKT, mTOR, ERK or IKK, involved in immune response pathways. Deregulation of 28 miRNA is observed between EC-LTNP and viremic-LTNP, including previously described anti-HIV miRNAs: miR-29a, associated with LTNP phenotype, and miR-155, targeting different pre-integration complexes such as ADAM10 and TNPO3. A holistic perspective of the changes observed in the miRNome of patients with different phenotypes of HIV-control and non-progression is provided.

Identification of a Novel Eight-lncRNA Prognostic Signature for HBV-HCC and Analysis of Their Functions Based on Coexpression and ceRNA Networks

Studies have demonstrated the prognosis potential of long noncoding RNAs (lncRNAs) for hepatocellular carcinoma (HCC), but specific lncRNAs for hepatitis B virus- (HBV-) related HCC have rarely been reported. This study was aimed at identifying a lncRNA prognostic signature for HBV-HCC and exploring their underlying functions. The sequencing dataset was collected from The Cancer Genome Atlas database as the training set, while the microarray dataset was obtained from the European Bioinformatics Institute database (E-TABM-36) as the validation set. Univariate and multivariate Cox regression analyses identified that eight lncRNAs (TSPEAR-AS1, LINC00511, LINC01136, MKLN1-AS, LINC00506, KRTAP5-AS1, ZNF252P-AS1, and THUMPD3-AS1) were significantly associated with overall survival (OS). These eight lncRNAs were used to construct a risk score model. The Kaplan-Meier survival curve results showed that this risk score can significantly differentiate the OS between the high-risk group and the low-risk group. Receiver operating characteristic curve analysis demonstrated that this risk score exhibited good prediction effectiveness (area under the curve (AUC) = 0.990 for the training set; AUC = 0.903 for the validation set). Furthermore, this lncRNA risk score was identified as an independent prognostic factor in the multivariate analysis after adjusting other clinical characteristics. The crucial coexpression (LINC00511-CABYR, THUMPD3-AS1-TRIP13, LINC01136-SFN, LINC00506-ANLN, and KRTAP5-AS1/TSPEAR-AS1/MKLN1-AS/ZNF252P-AS1-MC1R) or competing endogenous RNA (THUMPD3-AS1-hsa-miR-450a-TRIP13) interaction axes were identified to reveal the possible functions of lncRNAs. These genes were enriched into cell cycle-related biological processes or pathways. In conclusion, our study identified a novel eight-lncRNA prognosis signature for HBV-HCC patients and these lncRNAs may be potential therapeutic targets.

Regulation of cancer stem cell properties, angiogenesis, and vasculogenic mimicry by miR-450a-5p/SOX2 axis in colorectal cancer

Growing evidence indicates that a small number of cancer cells express stem cell markers and possess stem cell-like properties that promote malignant progression. Sex-determining region Y-box2 (SOX2) is a stem cell transcription factor essential for maintaining the properties of cancer stem cell (CSC). As CSC properties have been associated with angiogenesis and vasculogenic mimicry (VM), we aimed to comprehensively investigate whether SOX2 regulates CSC properties, angiogenesis, and VM in colorectal carcinoma (CRC) and its potential mechanism in this study. For this study, sphere formation assay, flow cytometry, cell survival analysis, tube formation, 3D culture, immunoblot, mouse model, and luciferase reporter assay were performed in vivo and in vitro. Expressions of SOX2 and miR-450a-5p in CRC tissue samples were examined through immunohistochemistry. First, the expression of SOX2 was not only associated with poor differentiation and prognosis but also promoted angiogenesis and VM. Knockdown of SOX2 ceased stemness properties, angiogenesis, and VM, along with decreased expression of CD133, CD31, and VE-cadherin as observed in functional experiments. Downregulation of SOX2 was found to inhibit tumorigenesis in vivo. Second, miR-450a-5p suppressed the expression of SOX2 by targeting its 3’UTR region directly and hence restrained SOX2-induced CSC properties, angiogenesis, and VM. Moreover, SOX2 overexpression preserved the miR-450a-5p-induced inhibition of CRC properties, angiogenesis, and VM. Finally, clinical samples exhibited a negative correlation between miR-450a-5p and SOX2. Patients with higher SOX2 and lower miR-450a-5p expressions had a poorer prognosis than patients with inverse expressions. Conclusively, we elucidated a unique mechanism of miR-450a-5p-SOX2 axis in the regulation of stemness, angiogenesis, and VM, which may act as a potential therapeutic practice in CRC.

Overexpression of miR-450 affects the biological behavior of HepG2 cells by targeting DNMT3a

Purpose

This study was designed to explore the regulation mechanism of miR-450 in the development of hepatocarcinoma, and the effects of overexpression of miR-450 on biological behaviors such as proliferation, migration, and invasion of hepatoma cells.

Methods

HepG2 cells were divided into miR-450 mimics group, miR-450 inhibitor group, miR-450 mimics NC group, miR-450 inhibitor NC group, and blank group. MTT assay was served to measure cell proliferation, and Transwell assay was used to test cell migration and invasion. Additionally, cell cycle was detected by flow cytometry and apoptosis was examined with AnnexinV-PI double staining. After the target gene of miR-450 was predicted by bioinformatics software, Western blot and dual luciferase reporter gene experiment were applied to verify the relationship between miR-450 and target gene.

Results

The MTT and Transwell assay indicated that overexpression of miR-450 inhibited the proliferation, invasion, and migration of HepG2 cells. The flow cytometry analysis showed that overexpression of miR-450 arrested the cell cycle in the G1 phase. Meanwhile, Annexin V-PI double staining assay revealed that overexpression of miR-450 promoted apoptosis of HepG2 cells. However, silencing miR-450 in HepG2 cells promoted proliferation and invasion, and reduced apoptosis. Moreover, we found that DNMT3a was the target gene of miR-450.

Conclusions

miR-450 could inhibit proliferation, invasion, and migration via regulating DNMT3a in hepatocarcinoma cells, which provided a theoretical basis for the treatment of liver cancer.

TNF-α-induced miR-450a mediates TMEM182 expression to promote oral squamous cell carcinoma motility

Distant metastasis leads oral cancer patients into a poor survival rate and a high recurrence stage. During tumor progression, dysregulated microRNAs (miRNAs) have been reported to involve tumor initiation and modulate oral cancer malignancy. MiR-450a was significantly upregulated in oral squamous cell carcinoma (OSCC) patients without functional reports. This study was attempted to uncover the molecular mechanism of novel miR-450a in OSCC. Mir-450a expression was examined by quantitative RT-PCR, both in OSCC cell lines and patients. Specific target of miR-450a was determined by software prediction, luciferase reporter assay, and correlation with target protein expression. The functions of miR-450a and TMEM182 were accessed by adhesion and transwell invasion analyses. Determination of the expression and cellular localization of TMEM182 was examined by RT-PCR and by immunofluorescence staining. The signaling pathways involved in regulation of miR-450a were investigated using the kinase inhibitors. Overexpression of miR-450a in OSCC cells impaired cell adhesion ability and induced invasiveness, which demonstrated the functional role of miR-450a as an onco-miRNA. Interestingly, tumor necrosis factor alpha (TNF-α)-mediated expression of TMEM182 was regulated by miR-450a induction. MiR-450a-reduced cellular adhesion was abolished by TMEM182 restoration. Furthermore, the oncogenic activity of TNF-α/miR-450a/TMEM182 axis was primarily through activating extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway. ERK1/2 inhibitor prevented the TNF-α-induced miR-450a expression and enhanced adhesion ability. Our data suggested that TNF-α-induced ERK1/2-dependent miR-450a against TMEM182 expression exerted a great influence on increasing OSCC motility. Overall, our results provide novel molecular insights into how TNF-α contributes to oral carcinogenesis through miR-450a that targets TMEM182.

Bioinformatics facilitating the use of microarrays to delineate potential miRNA biomarkers in aristolochic acid nephropathy

Aristolochic acid nephropathy (AAN) is a rapidly progressive acute or chronic tubulointerstitial nephritis (TIN). The present study attempted to explore the molecular mechanisms underlying the miRNA-directed development of AAN. Our differentially expressed analysis identified 11 DE-miRNAs and retrieved the target genes of these DE-miRNAs; then, network analysis and functional analysis further identified 6 DE-miRNAs (has-miR-192, has-miR-194, has-miR-542-3p, has-miR-450a, has-miR-584, has-miR-33a) as phenotypic biomarkers of AAN. Surprisingly, of has-miR-192 has been reported to be associated with the pathogenesis of AAN, and has-miR-194, has-miR-542-3p and has-miR-450a was first-time identified to link to the development of AAN. In addition, the expressional changes of has-miR-584 and has-miR-33a may be associated with the development of AAN as well, which must be further confirmed by the associated experiments. Taken together, our work reveals for the first time the regulatory mechanisms of miRNAs in the development of AAN and this will contribute to miRNA-based diagnosis and treatment of AAN.

Genome-wide miRNA response to anacardic acid in breast cancer cells

MicroRNAs are biomarkers and potential therapeutic targets for breast cancer. Anacardic acid (AnAc) is a dietary phenolic lipid that inhibits both MCF-7 estrogen receptor α (ERα) positive and MDA-MB-231 triple negative breast cancer (TNBC) cell proliferation with IC50s of 13.5 and 35 μM, respectively. To identify potential mediators of AnAc action in breast cancer, we profiled the genome-wide microRNA transcriptome (microRNAome) in these two cell lines altered by the AnAc 24:1n5 congener. Whole genome expression profiling (RNA-seq) and subsequent network analysis in MetaCore Gene Ontology (GO) algorithm was used to characterize the biological pathways altered by AnAc. In MCF-7 cells, 69 AnAc-responsive miRNAs were identified, e.g., increased let-7a and reduced miR-584. Fewer, i.e., 37 AnAc-responsive miRNAs were identified in MDA-MB-231 cells, e.g., decreased miR-23b and increased miR-1257. Only two miRNAs were increased by AnAc in both cell lines: miR-612 and miR-20b; however, opposite miRNA arm preference was noted: miR-20b-3p and miR-20b-5p were upregulated in MCF-7 and MDA-MB-231, respectively. miR-20b-5p target EFNB2 transcript levels were reduced by AnAc in MDA-MB-231 cells. AnAc reduced miR-378g that targets VIM (vimentin) and VIM mRNA transcript expression was increased in AnAc-treated MCF-7 cells, suggesting a reciprocal relationship. The top three enriched GO terms for AnAc-treated MCF-7 cells were B cell receptor signaling pathway and ribosomal large subunit biogenesis and S-adenosylmethionine metabolic process for AnAc-treated MDA-MB-231 cells. The pathways modulated by these AnAc-regulated miRNAs suggest that key nodal molecules, e.g., Cyclin D1, MYC, c-FOS, PPARγ, and SIN3, are targets of AnAc activity.

MiR-30b-5p acts as a tumor suppressor, repressing cell proliferation and cell cycle in human hepatocellular carcinoma

MicroRNAs have been verified to participate in various biological behaviors of different tumors, via multiple signaling pathways. Many kinds of microRNAs in hepatocellular carcinoma have been researched. However, miR-30b-5p hasn't been included. Our study aim at the impacts of miR-30b-5p on HCC and the pathway it mediating. The results showed miR-30b-5p was significant downregulated in HCC tissues and cell lines. With clinical data, we've discovered miR-30b-5p was correlated with several clinical pathological characteristics, such as survival time, tumor size, HBV infected, pathological stage, differentiation and intrahepatic metastasis. Also we illustrated miR-30b-5p repressed cell proliferation and cell cycle of HCC cell lines. For a further study, we figured out that miR-30b-5p mediated DNMT3A to repress proliferation, meanwhile it targeted USP37 for decelerating cell cycle. This discovery inferred miR-30b-5p a potential favorable biomarker and therapeutic target for HCC diagnosis and treatment.

A comparison of microRNA expression profiles from splenic hemangiosarcoma, splenic nodular hyperplasia, and normal spleens of dogs

Background

Splenic masses are common in older dogs; yet diagnosis preceding splenectomy and histopathology remains elusive. MicroRNAs (miRNAs) are short, non-coding RNAs that play a role in post-transcriptional regulation, and differential expression of miRNAs between normal and tumor tissue has been used to diagnose neoplastic diseases. The objective of this study was to determine differential expression of miRNAs by use of RNA-sequencing in canine spleens that were histologically confirmed as hemangiosarcoma, nodular hyperplasia, or normal.

Results

Twenty-two miRNAs were found to be differentially expressed in hemangiosarcoma samples (4 between hemangiosarcoma and both nodular hyperplasia and normal spleen and 18 between hemangiosarcoma and normal spleen only). In particular, mir-26a, mir-126, mir-139, mir-140, mir-150, mir-203, mir-424, mir-503, mir-505, mir-542, mir-30e, mir-33b, mir-365, mir-758, mir-22, and mir-452 are of interest in the pathogenesis of hemangiosarcoma.

Conclusions

Findings of this study confirm the hypothesis that miRNA expression profiles are different between canine splenic hemangiosarcoma, nodular hyperplasia, and normal spleens. A large portion of the differentially expressed miRNAs have roles in angiogenesis, with an additional group of miRNAs being dysregulated in vascular disease processes. Two other miRNAs have been implicated in cancer pathways such as PTEN and cell cycle checkpoints. The finding of multiple miRNAs with roles in angiogenesis and vascular disease is important, as hemangiosarcoma is a tumor of endothelial cells, which are driven by angiogenic stimuli. This study shows that miRNA dysregulation is a potential player in the pathogenesis of canine splenic hemangiosarcoma.

High protein/fish oil diet prevents hepatic steatosis in NONcNZO10 mice; association with diet/genetics-regulated micro-RNAs

OBJECTIVE

NONcNZO10 (NZ10) mice are predisposed to obesity and develop type 2 diabetes (T2D) and hepatic steatosis even when maintained on a control diet (CD) of 6% fat. Studies were designed to determine whether this extreme susceptibility phenotype could be alleviated by diet and if so the molecular targets of diet.

METHODS

NZ10 and SWR/J (SWR) control mice were fed a CD or a test diet of high protein and fish oil (HPO) for 19 weeks and then analyzed for steatosis, blood chemistry, hepatic gene and micro-RNA expression.

RESULTS

HPO diet prevented steatosis, significantly increased serum adiponectin and reduced serum cholesterol and triglycerides only in NZ10 mice. The HPO diet repressed hepatic expression of fatty acid metabolic regulators including PPAR-γ, sterol regulatory element-binding protein-c1, peroxisome proliferator-activated receptor gamma co-activator-1, fatty acid synthase, fatty acid binding protein-4, and apolipoprotein A4 genes only in NZ10 mice. Also repressed by a HPO diet were adiponectinR2 receptor, leptin-R, PPAR-α, pyruvate dehydrogenase kinase isoforms 2 and 4, AKT2 and GSK3β. Micro-RNA (miR) arrays identified miRs that were diet and/or genetics regulated. QRTPCR confirmed increased expression of miR-205 and suppression of a series of miRs including miRs-411, 155, 335 and 21 in the NZ10-HPO group, each of which are implicated in the progression of diabetes and/or steatosis. Evidence is presented that miR-205 co-regulates with PPARγ and may regulate fibrosis and EMT during the progression of steatosis in the livers of NZ10-CD mice. The dietary responses of miR-205 are tissue-specific with opposite effects in adipose and liver.

CONCLUSION

The results confirm that a HPO diet overrides the genetic susceptibility of NZ10 mice and this correlates with the suppression of key genes and perhaps micro-RNAs involved in hyperglycemia, dyslipidemia and inflammation including master PPAR regulators, adiponectin and leptin receptors.

Characterization and Small RNA Content of Extracellular Vesicles in Follicular Fluid of Developing Bovine Antral Follicles

Exosomes and microvesicles (i.e., extracellular vesicles: EVs) have been identified within ovarian follicular fluid and recent evidence suggests that EVs are able to elicit profound effects on ovarian cell function. While existence of miRNA within EVs has been reported, whether EV size and concentration as well as their cargos (i.e., proteins and RNA) change during antral follicle growth remains unknown. Extracellular vesicles isolated from follicular fluid of small, medium and large bovine follicles were similar in size, while concentration of EVs decreased progressively as follicle size increased. Electron microscopy indicated a highly purified population of the lipid bilayer enclosed vesicles that were enriched in exosome biomarkers including CD81 and Alix. Small RNA sequencing identified a large number of known and novel miRNAs that changed in the EVs of different size follicles. Ingenuity Pathway Analysis (IPA) indicated that miRNA abundant in small follicle EV preparations were associated with cell proliferation pathways, while those miRNA abundant in large follicle preparations were related to inflammatory response pathways. These studies are the first to demonstrate that EVs change in their levels and makeup during antral follicle development and point to the potential for a unique vesicle-mediated cell-to-cell communication network within the ovarian follicle.

MicroRNAs dysregulation in hepatocellular carcinoma: Insights in genomic medicine

Hepatocellular carcinoma (HCC) is the leading primary liver cancer and its clinical outcome is still poor. MicroRNAs (miRNAs) have demonstrated an interesting potential to regulate gene expression at post-transcriptional level. Current findings suggest that miRNAs deregulation in cancer is caused by genetic and/or epigenetic, transcriptional and post-transcriptional modifications resulting in abnormal expression and hallmarks of malignant transformation: aberrant cell growth, cell death, differentiation, angiogenesis, invasion and metástasis. The important role of miRNAs in the development and progression of HCC has increased the efforts to understand and develop mechanisms of control overt this single-stranded RNAs. Several studies have analyzed tumoral response to the regulation and control of deregulated miRNAs with good results in vitro and in vivo, proving that targeting aberrant expression of miRNAs is a powerful anticancer therapeutic. Identification of up and/or down regulated miRNAs related to HCC has led to the discovery of new potential application for detection of their presence in the affected organism. MiRNAs represent a relevant new target for diagnosis, prognosis and treatment in a wide variety of pathologic entities, including HCC. This manuscript intends to summarize current knowledge regarding miRNAs and their role in HCC development.

miRNA in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. Despite improvements in HCC therapy, the prognosis for HCC patients remains poor due to a high incidence of recurrence. An improved understanding of the pathogenesis of HCC development would facilitate the development of more effective outcomes for the diagnosis and treatment of HCC at earlier stages. miRNA are small, endogenous, non-coding, ssRNA that are 21-30 nucleotides in length and modulate the expression of various target genes at the post-transcriptional and translational levels. Aberrant expression of miRNA is common in various human malignancies and modulates cancer-associated genomic regions or fragile sites. As for the relationship between miRNA and HCC, several studies have demonstrated that the aberrant expression of specific miRNA can be detected in HCC cells and tissues. However, little is known about the mechanisms of miRNA-related cell proliferation and development. In this review, we summarize the central and potential roles of miRNA in the pathogenesis of HCC and elucidate new possibilities that may be useful as diagnostic and prognostic markers, as well as novel therapeutic targets in HCC.

Identification of differentially expressed microRNAs in human hepatocellular adenoma associated with type I glycogen storage disease: a potential utility as biomarkers

BACKGROUND

It is known that malignant transformation to hepatocellular carcinoma (HCC) occurs at a higher frequency in hepatocellular adenoma (HCA) from type I glycogen storage disease (GSD I) compared to HCA from other etiologies. In this study, we aimed to identify differentially expressed miRNAs in GSD Ia HCA as candidates that could serve as putative biomarkers for detection of GSD Ia HCA and/or risk assessment of malignant transformation.

METHODS

Utilizing massively parallel sequencing, the miRNA profiling was performed for paired adenomas and normal liver tissues from seven GSD Ia patients. Differentially expressed miRNAs were validated in liver tumor tissues, HCC cell lines and serum using quantitative RT-PCR.

RESULTS

miR-34a, miR-34a, miR-224, miR-224, miR-424, miR-452 and miR-455-5p were found to be commonly deregulated in GSD Ia HCA, general population HCA, and HCC cell lines at compatible levels. In comparison with GSD Ia HCA, the upregulation of miR-130b and downregulation of miR-199a-5p, miR-199b-5p, and miR-214 were more significant in HCC cell lines. Furthermore, serum level of miR-130b in GSD Ia patients with HCA was moderately higher than that in either GSD Ia patients without HCA or healthy individuals.

CONCLUSION

We make the first observation of distinct miRNA deregulation in HCA associated with GSD Ia. We also provide evidence that miR-130b could serve as a circulating biomarker for detection of GSD Ia HCA. This work provides prominent candidate miRNAs worth evaluating as biomarkers for monitoring the development and progress of liver tumors in GSD Ia patients in the future.

Epigenetics and ncRNAs in brain function and disease: mechanisms and prospects for therapy

The most fundamental roles of non-coding RNAs (ncRNAs) and epigenetic mechanisms are the guidance of cellular differentiation in development and the regulation of gene expression in adult tissues. In brain, both ncRNAs and the various epigenetic gene regulatory mechanisms play a fundamental role in neurogenesis and normal neuronal function. Thus, epigenetic chromatin remodelling can render coding sites transcriptionally inactive by DNA methylation, histone modifications or antisense RNA interactions. On the other hand, microRNAs (miRNAs) are ncRNA molecules that can regulate the expression of hundreds of genes post-transcriptionally, typically recognising binding sites in the 3' untranslated region (UTR) of mRNA transcripts. Furthermore, there are a myriad of interactions in the interface of miRNAs and epigenetics. For example, epigenetic mechanisms can silence miRNA coding sites, and miRNAs can be the effectors of transcriptional gene silencing, targeting complementary promoters or silencing the expression of epigenetic modifier genes like MECP2 and EZH2 leading to global changes in the epigenome. Alterations in this regulatory machinery play a key role in the pathology of complex disorders including cancer and neurological diseases. For example, miRNA genes are frequently inactivated by epimutations in gliomas. Here we describe the interactions between epigenetic and ncRNA regulatory systems and discuss therapeutic potential, with an emphasis on tumors, cognitive disorders and neurodegenerative diseases.

microRNA-199a-3p, DNMT3A, and aberrant DNA methylation in testicular cancer

It was previously demonstrated that miR-199a was downregulated in testicular germ cell tumor (TGCT), probably due to hypermethylation of its promoter. Further study found that re-expression of miR-199a in testicular cancer cells (NT2) led to suppression of cell growth, cancer migration, invasion and metastasis. More detailed analyses showed that these properties of miR-199a could be assigned to miR-199a-5p, one of its two derivatives. The biological role of the other derivative, miR-199a-3p in TGCT, remains largely uncharacterized. In this report, we identified DNA (cytosine-5)-methyltransferase 3A (DNMT3A), the de novo methyltransferase, as a direct target of miR-199a-3p using a 3'-UTR reporter assay. Transient expression of miR-199a-3p in NT2 cells led to decrease, while knocking down of miR-199a-3p in a normal human testicular cell line (HT) led to elevation, of DNMT3A2 (DNMT3A gene isoform 2) mRNA and protein levels. In clinical samples, DNMT3A2 was significantly overexpressed in malignant testicular tumor, and the expression of DNMT3A2 was inversely correlated with the expression of miR-199a-3p. However, DNMT3A did not affect miR-199a expression in NT2 cells. Further characterization of miR-199a-3p revealed that it negatively regulated DNA methylation, partly through targeting DNMT3A. Overexpression of miR-199a-3p restored the expression of APC and MGMT tumor-suppressor genes in NT2 cells by affecting DNA methylation of their promoter regions. Our studies demonstrated the deregulation of miR-199a-3p expression in TGCT may provide novel mechanistic insights into TGCT carcinogenesis and suggested a potentially therapeutic use of synthetic miR-199a-3p oligonucleotides as effective hypomethylating compounds in the treatment of TGCT.

Clinical implications of microRNAs in liver cancer stem cells

The prognosis of patients diagnosed with hepatocellular carcinoma (HCC) is often dismal, mainly due to late presentation, high recurrence rate, and frequent resistance to chemotherapy and radiotherapy. Accumulating evidence on the differential microRNA (miRNA) expression patterns between non-tumor and HCC tissues or between liver cancer stem cells (CSCs) and non-CSC subsets and the significant clinical implications of these differences suggest that miRNAs are a promising, non-invasive marker for the prognosis and diagnosis of the disease. This perspective article summarizes the current knowledge of miRNAs in liver CSCs and highlights the need for further investigations of the role of miRNAs in regulating liver CSC subsets for possible future clinical applications.

MicroRNAs in hepatocellular carcinoma: regulation, function, and clinical implications

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and the third cause of cancer-related death. Poor understanding of the mechanisms underlying the pathogenesis of HCC makes it difficult to be diagnosed and treated at early stage. MicroRNAs (miRNAs), a class of noncoding single-stranded RNAs of ~22 nucleotides in length, posttranscriptionally regulate gene expression by base pairing with the 3' untranslated regions (3'UTRs) of target messenger RNAs (mRNAs). Aberrant expression of miRNAs is found in many if not all cancers, and many deregulated miRNAs have been proved to play crucial roles in the initiation and progression of cancers by regulating the expression of various oncogenes or tumor suppressor genes. In this Paper, we will summarize the regulations and functions of miRNAs aberrantly expressed in HCC and discuss the potential application of miRNAs as diagnostic and prognostic biomarkers of HCC and their potential roles in the intervention of HCC.