Expression of Circulating miR-155, miR-21, miR-221, miR-30a, miR-34a and miR-29a: Comparison of Colonic and Rectal Cancer

BACKGROUND

Colorectal cancer is an increasing cause of death. Circulating microRNAs (miRs) could be great diagnostic and prognostic biomarkers of colorectal cancer, but further continuation of their utility is needed for their comprehensive application.

MATERIALS AND METHODS

Twenty-seven patients with colonic cancer, 16 with rectal cancer and 12 healthy volunteers as controls, were involved in this study. Expression of miR-155, miR-21, miR-221, miR-30a, miR-34a and miR-29a were determined by reverse transcription polymerase chain reaction (RT-PCR) from sera of patients.

RESULTS

Expression of miR-155, miR-21 and miR-221 was significantly higher in rectal cancer than in colonic cancer. There was no difference found between those with TNM1 cancer and controls for both cancer types. miR-155, miR-34a and miR-29a were down-regulated in all patients with cancer compared to controls. We did not find any statistically significant up-regulation of miR-221 in patients with colonic cancer compared to controls. In contrast, in patients with rectal cancer, miR-221 expression was higher than in controls. Advanced stage was also linked to higher miR-221 expression compared to early stage. Slight, but statistically significant increase was observed in miR-30a expression in patients with colon cancer compared to control individuals.

CONCLUSION

Our results partly support previous findings. Here we report on differences in the expression of circulating microRNA between colonic and rectal tumours for the first time.

Liquid biopsy: miRNA as a potential biomarker in oral cancer

Oral cancer is one of the leading cancers in South-Asian countries. Despite the easy access of the oral cavity, the detection and five year survival rates of OSCC patients are dismal. Identification of non-invasive biomarkers to determine the progression and recurrence of OSCC could be of immense help to patients. Recent studies on oral cancer suggest the importance of non-invasive biomarker development. Micro-RNAs (miRNAs) are one of the important components of the cell-free nucleic acids available in different body fluids. Here, we have reviewed the current understanding of circulating miRNAs as non-invasive biomarkers in different body fluids of oral cancer patients. A number of circulating miRNAs are found to be common in the body fluids of OSCC patients, while many of these are study specific, the possible sources of this variability could be due to differences in sample processing, assay procedure, clinical stage of the disease, oral habit and environmental factors. The prognostic and therapeutic significance of these circulating miRNAs are suggested by several studies. Mir-371, mir-150, mir-21 and mir-7d were found to be potential prognostic markers, while mir-134, mir-146a, mir-338 and mir-371 were associated with metastases. The prognostic markers, mir-21 and mir-7d were also found to be significantly correlated with resistance to chemotherapy, while mir-375, mir-196 and mir-125b were significantly correlated with sensitivity to radiotherapy. Despite the promising roles of circulating miRNAs, challenges still remain in unravelling the exact regulation of these miRNAs before using them for targeted therapy.

Plasmatic and chamber-specific modulation of cardiac microRNAs in an acute model of DOX-induced cardiotoxicity

BACKGROUND

Doxorubicin (DOX) is a chemotherapeutic drug limited in its usefulness by an adverse side effect, cardiotoxicity. The mechanisms leading to this detrimental occurrence are not completely clear, and lately many authors focused their attention on the possible role of microRNAs (miRNAs), small regulators of cardiovascular functions, in this phenomenon. Notably, these molecules recently emerged also as potential circulating biomarkers of several cardiac diseases. Thus, the aim of this study was the simultaneous investigation of circulating and cardiac tissue miRNAs expression upon DOX treatment in vivo.

METHODS

Twenty C57BL/6 female mice were administered with 24 mg/Kg cumulative dose of DOX or saline (CTRL) for 2 weeks. Echocardiography was performed at baseline and at the end of treatment (T1). Plasma and heart samples were collected at T1, separating atria from left (LV) and right (RV) ventricles, and miRNAs expression was tested by RT-qPCR-based arrays. All putatively DOX-regulated candidates were then validated by single assays in vivo and then evaluated also in murine immortalized cardiomyocytes (HL-1) treated with 1 μM DOX for 24 h. In the end, bioinformatics target prediction was performed for all DOX-miRNAs.

RESULTS

Cardiotoxicity onset was diagnosed upon impairment of six cardiac functional parameters in DOX-treated mice at T1. Samples collection, followed by screening and validation steps, identified eleven miRNAs dysregulated by the drug in plasma, while seven resulted as altered in separate heart chambers. Interestingly, miR-34a-5p and miR-451a showed a dysregulation in both plasma and tissue samples of DOX-administered animals, whereas five additional miRNAs presented chamber specific modulation. Of note, in vitro experiments showed a very modest overlap with in vivo results. Bioinformatics prediction analysis performed on miR-34a-5p and miR-451a identified several putative targets presenting no significant association with cardiotoxicity. Anyhow, the same analyses, conducted by combining all miRNAs regulated by DOX in each heart chamber, evidenced a possible dysregulation of the adherens junctions gene network, known to be involved in the onset and progression of dilated cardiomyopathy, an established detrimental side effect of the drug.

CONCLUSIONS

This is the first work investigating miRNAs regulation by DOX both in plasma and heart districts of treated animals. Our results indicate a strong association of miR-34a-5p and miR-451a to DOX-induced cardiotoxicity. In addition, the observed altered expression of diverse miRNAs in separated cardiac chambers hints at a specific response to the drug, implying the existence of different players and pathways leading to dysfunction onset.

Data on transcriptome profiling of circulating microRNAs in dairy cattle

MicroRNA (miRNA) are found in numerous biofluids including blood and are considered a new class of biomarkers. The data presented here are related to the research article entitled “Profiling and identification of pregnancy-associated circulating microRNAs in dairy cattle” (Markkandan et al. 2018). In the cited article, we sequenced the circulating microRNAs of the three healthy dairy cows of normal and 30 days of pregnancy (DOP) using Illumina RNA-Seq. Differentially expressed genes (DEG) analysis between normal and pregnant samples showed perturbations in miRNA expression. Herein, we made a comparison of DEGs at normal and 60 DOP libraries. The analysis results showed that 147 known miRNAs were differently expressed at 60 DOP groups when compared to the normal group. In addition, stage specific miRNAs were also predicted.

Sex differences in miRNA as therapies for ischemic stroke

MicroRNAs, a subset of non-coding RNAs, are present in virtually all tissues including body fluids and are global regulators of the transcriptome. In view of the expanding number of microRNAs and the large number of gene targets that each microRNA can potentially regulate, they have been compared to hormones in the scope of their effects. MicroRNA have been implicated as biomarkers for several diseases including stroke, as well as chronic conditions that are associated with stroke. Recent research has focused on manipulating miRNA to improve stroke outcomes. Although several miRNAs have been shown to have neuroprotective properties, the overwhelming majority of these studies have employed only male animals. This review will focus on two miRNAs, Let7f and mir363-3p, whose effectiveness as a stroke neuroprotectant is sex-specific.

Dynamic changes of circulating miRNAs induced by the Ebola virus vaccine VSV-EBOV

VSV-EBOV is a replication-competent Ebola virus (EBOV) vaccine, which was tested in clinical trials as response to the Ebola virus disease (EVD) outbreak 2013-2016. It is the most advanced EBOV candidate currently in the licensure process. The experimental vaccine was again administered as response to outbreaks in the Democratic Republic of Congo. However, underlying molecular mechanisms that convey protection remain incompletely understood. MicroRNAs (miRNAs) are known key regulators that influence gene expression on a post-transcriptional level. The miRNA-mediated control has emerged as a critical regulatory principle in the immune system, which strongly influences the balance of innate and adaptive immune responses by modulation of signaling pathways critical for differentiation of immune cells. We investigated expression levels of circulating miRNAs (c-miRNAs) in plasma from healthy vaccinees, as they may reflect cellular dynamics following VSV-EBOV immunization and additionally may serve as potential biomarkers for vaccine efficacy. As part of the WHO-led VEBCON consortium, we investigated safety and immunogenicity of VSV-EBOV in a phase I trial. A comprehensive analysis of expression levels on c-miRNAs from plasma samples following VSV-EBOV immunization (day 0, 1, 3 post vaccination) was conducted using RT-qPCR assays. Potential biological relevance was assessed using in silico analyses. Additionally, we correlated dynamics of miRNA expressions with our previously reported data on vaccine-induced antibody and cytokine responses and finally evaluated the prognostic power by generating ROC curves. We identified four promising miRNAs (hsa-miR-146a, hsa-miR-126, hsa-miR-199a, hsa-miR-484), showing a strong association with adaptive immune responses, exhibited favourable prognostic performance and are implicated in immunology-related functions. Our results provide evidence that miRNAs may serve as useful biomarkers for prediction of vaccine-induced immunogenicity. Furthermore, our unique data set provides insight into molecular mechanisms that underlie VSV-EBOV-mediated protective immune responses, which may help to decipher VSV-EBOV immune signature and accelerate strategic vaccine design or personalized approaches.

Serum miRNAs miR-140-3p and miR-23b-3p as potential biomarkers for osteoporosis and osteoporotic fracture in postmenopausal Mexican-Mestizo women

Osteoporosis is a metabolic bone disorder characterized by low bone mineral density and decreased bone strength, leading to an increased risk of fractures with a consequent increase in morbidity and mortality. The current methods to estimate the fracture risk are very limited. microRNAs (miRNAs) have been considered as good biomarkers for many pathological processes, including osteoporosis. Some circulating miRNAs are associated with regulation of bone formation and differentiation of bone cells. The aim of this study, was to analyze the expression of miRNAs in serum of patients with osteoporosis (n = 20) and healthy controls (n = 20). Expression of 754 miRNAs was analyzed through quantitative real time RT-PCR arrays. Seven miRNAs showed significant differences between groups. The microRNAs miR-23b-3p, miR-140-3p and miR-885-5p were selected based on fold change and p-values (40.5, p = 0.038, 20.7, p = 0.045, and 2.2, p = 0.002; respectively) for validation in independent serum samples from patients with osteopenia (n = 28), osteoporosis (n = 26) and osteoporotic hip fracture (n = 21). After validation, we confirm differences across the groups for miR-23b-3p and miR-140-3p. Our data pointed miR-140-3p and miR-23b-3p as potential biomarkers candidates for osteoporosis in postmenopausal women.

Circulating miRNome profiling in Moyamoya disease-discordant monozygotic twins and endothelial microRNA expression analysis using iPS cell line

Background

Moyamoya disease (MMD) is characterized by progressive stenosis of intracranial arteries in the circle of Willis with unknown etiology even after the identification of a Moyamoya susceptible gene, RNF213. Recently, differences in epigenetic regulations have been investigated by a case-control study in MMD. Here, we employed a disease discordant monozygotic twin-based study design to unmask potential confounders.

Methods

Circulating genome-wide microRNA (miRNome) profiling was performed in MMD-discordant monozygotic twins, non-twin-MMD patients, and non-MMD healthy volunteers by microarray followed by qPCRvalidation, using blood samples. Differential plasma-microRNAs were further quantified in endothelial cells differentiated from iPS cell lines (iPSECs) derived from another independent non-twin cohort. Lastly, their target gene expression in the iPSECs was analyzed.

Results

Microarray detected 309 plasma-microRNAs in MMD-discordant monozygotic twins that were also detected in the non-twin cohort. Principal component analysis of the plasma-microRNA expression level demonstrated distinct 2 groups separated by MMD and healthy control in the twin- and non-twin cohorts. Of these, differential upregulations of hsa-miR-6722-3p/− 328-3p were validated in the plasma of MMD (absolute log2 expression fold change (logFC) > 0.26 for the twin cohort; absolute logFC > 0.26, p < 0.05, and q < 0.15 for the non-twin cohort). In MMD derived iPSECs, hsa-miR-6722-3p/− 328-3p showed a trend of up-regulation with a 3.0- or higher expression fold change. Bioinformatics analysis revealed that 41 target genes of miR-6722-3p/− 328-3p were significantly down-regulated in MMD derived iPSECs and were involved in STAT3, IGF-1-, and PTEN-signaling, suggesting a potential microRNA-gene expression interaction between circulating plasma and endothelial cells.

Conclusions

Our MMD-discordant monozygotic twin-based study confirmed a novel circulating microRNA signature in MMD as a potential diagnostic biomarker minimally confounded by genetic heterogeneity. The novel circulating microRNA signature can contribute for the future functional microRNA analysis to find new diagnostic and therapeutic target of MMD.

Electronic supplementary material

The online version of this article (10.1186/s12920-018-0385-3) contains supplementary material, which is available to authorized users.

Association of the peripheral blood levels of circulating microRNAs with both recurrent miscarriage and the outcomes of embryo transfer in an in vitro fertilization process

BACKGROUND

Implantation failure is not only a major cause of early pregnancy loss, but it is also an obstacle to assisted reproductive technologies. The identification of potential circulating biomarkers for recurrent miscarriage (RM) and/or recurrent implantation failure would contribute to the development of novel diagnosis and prediction techniques.

METHODS

MiR (miR-23a-3p, 27a-3p, 29a-3p, 100-5p, 127-3p and 486-5p) expression in the villi, decidual tissues and peripheral blood plasma and serum were validated by qPCR, and the localization of miRs in the villi and decidual tissues of RM and normal pregnancy (NP) women were detected by in situ hybridization. The invasiveness of HTR8/SVneo cells was determined using a Transwell assay. The predictive values of miRs for RM and the outcome of IVF-ET were respectively calculated by the receiver operating characteristic analysis.

RESULTS

The signals of six miRs were observed in the villi and decidual tissues of RM and NP women. The villus miR-27a-3p, miR-29a-3p and miR-100-5p were significantly up-regulated, whereas miR-127-3p and miR-486-5p appeared to be down-regulated in RM women compared to NP women. The invasiveness of HTR8/SVneo cells transfected with miR-23a-3p mimics was evidently weakened, whereas that of cells transfected with miR-127-3p mimics was obviously enhanced. The peripheral blood plasma levels of miR-27a-3p, miR-29a-3p, miR-100-5p and miR-127-3p were significantly increased, whereas that of miR-486-5p was remarkably decreased in RM compared to NP women. By contrast, serum miR-23a-3p and miR-127-3p were significantly decreased, whereas that of miR-486-5p was remarkably increased. The combination of six plasma miRs levels discriminated RM with a sensitivity of 100% and a specificity of 83.3%, whereas that of six serum miRs levels showed a sensitivity of 78.3% and a specificity of 93.1%. In the IVF-ET cohort, the significantly decreased peripheral blood plasma levels of miR-23a-3p, miR-27a-3p, miR-100-5p and miR-127-3p, and the serum levels of miR-100-5p and miR-486-5p, in addition to the significantly increased serum level of miR-27a-3p, were found to be associated with the failure of ET. Moreover, the combination of plasma miR-23a-3p, miR-27a-3p, miR-29a-3p, miR-100-5p, miR-127-3p and miR-486-5p levels discriminated the outcome of IVF-ET with a sensitivity of 68.1% and a specificity of 54.1%, whereas the combination of plasma miR-127-3p and miR-486-5p levels showed a sensitivity of 50.0% and a specificity of 75.3%.

CONCLUSIONS

Circulating miR-23a-3p, miR-27a-3p, miR-29a-3p, miR-100-5p, miR-127-3p and miR-486-5 might be involved in RM pathogenesis and present potential diagnostic biomarkers for RM. Meanwhile, these miRs, in particular miR-127-3p and miR-486-5p, provide promising prediction indexes for the outcomes of IVF-ET.

Circulating microRNAs and prediction of asthma exacerbation in childhood asthma

BACKGROUND

Circulating microRNAs have shown promise as non-invasive biomarkers and predictors of disease activity. Prior asthma studies using clinical, biochemical and genomic data have not shown excellent prediction of exacerbation. We hypothesized that a panel of circulating microRNAs in a pediatric asthma cohort combined with an exacerbation clinical score might predict exacerbation better than the latter alone.

METHODS

Serum samples from 153 children at randomization in the Childhood Asthma Management Program were profiled for 754 microRNAs. Data dichotomized for asthma exacerbation one year after randomization to inhaled corticosteroid treatment were used for binary logistic regression with miRNA expressions and exacerbation clinical score.

RESULTS

12 of 125 well-detected circulating microRNAs had significant odd ratios for exacerbation with miR-206 being most significant. Each doubling of expression of the 12 microRNA corresponded to a 25-67% increase in exacerbation risk. Stepwise logistic regression yielded a 3-microRNA model (miR-146b, miR-206 and miR-720) that, combined with the exacerbation clinical score, had excellent predictive power with a 0.81 AUROC. These 3 microRNAs were involved in NF-kβ and GSK3/AKT pathways.

CONCLUSIONS

This combined circulating microRNA-clinical score model predicted exacerbation in asthmatic subjects on inhaled corticosteroids better than each constituent feature alone.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00000575 .

MicroRNA profiles in serum samples from patients with stable cirrhosis and miRNA-21 as a predictor of transplant-free survival

MicroRNAs (miRNAs) have remarkable potential as diagnostic and prognostic markers because of their roles in disease pathogenesis. miRNAs can be released into the bloodstream, where they are sufficiently stable to be detected noninvasively. Here, we prospectively evaluated serum levels of miR-21, miR-34a, miR-122, miR-181b, and miR-885-5p in patients with stable cirrhosis. Total RNA was extracted from the sera of patients with cirrhosis and healthy individuals, and the expression levels of the target miRNAs were analyzed by reverse transcription-quantitative polymerase chain reaction. Serum miRNAs levels were correlated with liver function parameters, etiology, and complications of cirrhosis. Circulating miR-34a, miR-122, and miR-885-5p levels were higher in patients with cirrhosis than in healthy individuals. These miRNAs were positively correlated with alanine aminotransferase and aspartate aminotransferase levels, and the relative expression levels were higher in hepatitis C virus-infected patients and lower in patients with Child-Pugh C cirrhosis. miR-122 and miR-885-5p levels were also positively correlated with γ-glutamyl transpeptidase concentrations. miR-21 was associated with transplant-free survival in univariate Cox regression analysis and remained independently associated with survival after adjustment for age, Child-Pugh classification, Model for End-stage Liver Disease score, and history of previous decompensation in multivariate Cox regression analysis. These data suggested that miR-34a, miR-122, and miR-885-5p levels may be more related to the inflammatory process and ongoing hepatocyte damage in patients with cirrhosis. Moreover, miR-21 levels were independently associated with shorter transplant-free survival and may be used as a prognostic tool in outpatients with stable cirrhosis.

Circulating MicroRNAs: a Potential Biomarker for Cardiac Damage, Inflammatory Response, and Left Ventricular Function Recovery in Pediatric Viral Myocarditis

Viral myocarditis (VM) can be a life-threatening event resulting in cardiac failure, chronic cardiomyopathy, and death. VM typically includes three phases, i.e., acute, subacute, and resolution/chronic. We prospectively investigated cardiac- and inflammatory-associated plasma-circulating miRNA levels in eight pediatric patients with VM during the three stages of the disease. The level of cardiac-associated miR-208a was significantly elevated during the acute phase compared with the subacute and resolution/chronic phases. The level of cardiac- and inflammatory-associated miR-21 was significantly elevated during the acute phase compared to the resolution/chronic phase. Moreover, cardiac-associated miR-208b levels during the subacute phase correlated with systolic left ventricular function recovery as measured during the resolution/chronic phase. The findings of our study demonstrate an association between cardiac damage and the inflammatory response and the expression of miR-208a and miR-21 during the pathological progression of myocarditis. We also found that miR-208b levels exhibit a prognostic significance for left ventricular functional recovery.

Microcystin-LR-Triggered Neuronal Toxicity in Whitefish Does Not Involve MiR124-3p

Microcystin-LR (MC-LR) is a potent hepatotoxin that has also been pointed out of causing neurotoxicity, but the exact mechanisms of action still remain ambiguous and need to be elucidated. Data from studies on mammals show that pathology of astrocyte cells points to perturbations of microRNA signaling. Glial fibrillary acidic protein (GFAP), a neuronal cell/astrocyte-specific protein, and a microRNA-124-3p (MiR124-3p) are among putative triggers and regulators of neuronal cell/astrocyte reactivity. In the present study on whitefish (Coregonus lavaretus), we found that gfap mRNA contains a putative target site for MIR124-3p, to potentially affect its expression changes. qPCR expression study of gfap:MiR124-3p pair in the midbrain of juvenile whitefish, during 28 days of exposure to a repeated subacute dose of MC-LR (100 μg kg⁻¹ body mass), showed marginally significant up-regulation of gfap only on the 7th day of exposure period which suggests neuronal toxicity. During the whole exposure period, neither midbrain nor blood plasma levels of MiR124-3p were changed. Furthermore, double luciferase gene reporter assay confirmed the lack of MiR124-3p involvement in mediating control over gfap mRNA expression. These data show that, although MC-LR may trigger neuronal toxicity in whitefish, this does not involve MiR124-3p in response to the treatment.

Changes in the Expression of Circulating microRNAs in Systemic Lupus Erythematosus Patient Blood Plasma After Passing Through a Plasma Adsorption Membrane

MicroRNAs (miRNAs, miRs) are small non-coding RNAs that mainly function in the post-transcriptional regulation of genes. miRNA that is secreted outside of cells, and which circulates in the peripheral blood, is called circulating microRNA. Systemic lupus erythematosus (SLE) is a typical autoimmune connective tissue disease and is mainly treated with immunosuppressive drugs. Therapeutic apheresis is often used to eliminate autoantibodies and cytokines. We have previously shown that circulating miRNAs in the blood of patients with SLE can be separated and removed from the blood using a plasma separation membrane. In the present study, we further separated circulating miRNA from three SLE patient's blood plasma by passing it through a plasma adsorption membrane, and then measured changes in miRNA levels using miRNAs microarray chip. Although the levels of many miRNAs were unaffected after passage through the plasma adsorption membrane, expression of some miRNAs, including miR-1246, miR-4732-5p, and miR-6088 are declined.

Serum miR-22 as potential non-invasive predictor of poor clinical outcome in newly diagnosed, uniformly treated patients with diffuse large B-cell lymphoma: an explorative pilot study

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous group of tumors, with aggressive clinical course that renders prognostication and choice of treatment strategy difficult. Chemo-immunotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP) is the current first-line treatment. MicroRNAs (miRNAs) are under investigation as novel diagnostic and prognostic biomarkers in several malignancies, including malignant lymphomas. While tissue miRNAs in DLBCL patients have been extensively studied as biomarkers, only few reports to date have evaluated the role of circulating/serum miRNAs as potential prognostic factors. Here circulating/serum miRNAs, including miR-22, were investigated as potential non-invasive biomarkers, with the aim of a better prognostic stratification of DLBCL patients.

METHODS

MiRNAs were selected by global expression profile of serum miRNAs of DLBCL patients, The Cancer Genome Atlas (TCGA) analysis and literature research. Serum and tissues miRNA expression profile in de novo DLBCL patients, consecutively enrolled for this study, were detected by quantitative real-time polymerase chain reaction. Relative expression was calculated using the comparative Ct method. Statistical significance was determined using the Mann-Whitney rank sum and Fisher's exact test. Survival analysis was conducted through the use of Kaplan-Meier method. Spearman's Rho was applied to study the correlation between miRNA distributions and days to first relapse. Experimentally validated miRNA-target interactions were assessed by miRTarBase database. Negative miRNA-mRNA correlation was evaluated in TCGA DLBCL dataset. Pathway analysis was performed by the functional annotation clustering DAVID tool.

RESULTS

We showed a significant modulation of serum miR-22 after R-CHOP treatment compared with basal values but no difference between baseline serum miRNAs values of DLBCL patients and healthy controls. High expression level of serum miR-22 in DLBCL at diagnosis (n = 36) is associated with a worse PFS and is independent of the currently used clinical prognostic index. Integrative and pathways analysis of miR-22 identified target genes involved in different important pathways such as p53 signaling.

CONCLUSIONS

Our data suggest that miR-22 is of potential interest as non-invasive biomarker to predict clinical outcome in DLBCL patients. Characterization of miR-22 pathways can pave the way to the development of targeted therapy approaches for specific subgroups of DLBCL patients.

Circulating microRNAs as potential cancer biomarkers: the advantage and disadvantage

MicroRNAs are endogenous single-stranded non-coding small RNA molecules that can be secreted into the circulation and exist stably. They usually exhibit aberrant expression under different physiological and pathological conditions. Recently, differentially expressed circulating microRNAs were focused on as potential biomarkers for cancer screening. We herein review the role of circulating microRNAs for cancer diagnosis, tumor subtype classification, chemo- or radio-resistance monitoring, and outcome prognosis. Moreover, circulating microRNAs still have several issues hindering their reliability for the practical clinical application. Future studies need to elucidate further potential application of circulating microRNAs as specific and sensitive markers for clinical diagnosis or prognosis in cancers.

Circulating microRNAs from the miR-106a-363 cluster on chromosome X as novel diagnostic biomarkers for breast cancer

PURPOSE

Novel noninvasive biomarkers with high sensitivity and specificity for the diagnosis of breast cancer (BC) are urgently needed in clinics. The aim of this study was to explore whether miRNAs from the miR-106a-363 cluster can be detected in the circulation of BC patients and whether these miRNAs can serve as potential diagnostic biomarkers.

METHODS

The expression of 12 miRNAs from the miR-106a-363 cluster was evaluated using qRT-PCR in 400 plasma samples (from 200 BC patients and 200 healthy controls (HCs)) and 406 serum samples (from 204 BC patients and 202 HCs) via a three-phase study. The identified miRNAs were further examined in tissues (32 paired breast tissues), plasma exosomes (from 32 BC patients and 32 HCs), and serum exosomes (from 32 BC patients and 32 HCs).

RESULTS

Upregulated levels of four plasma miRNAs (miR-106a-3p, miR-106a-5p, miR-20b-5p, and miR-92a-2-5p) and four serum miRNAs (miR-106a-5p, miR-19b-3p, miR-20b-5p, and miR-92a-3p) were identified and validated in BC. A plasma 4-miRNA panel and a serum 4-miRNA panel were constructed to discriminate BC patients from HCs. The areas under the receiver-operating characteristic curves of the plasma panel were 0.880, 0.902, and 0.858, and those of the serum panel were 0.910, 0.974, and 0.949 for the training, testing, and external validation phases, respectively. Two overlapping miRNAs (miR-106a-5p and miR-20b-5p) were consistently upregulated in BC tissues. Except for the expression of the plasma-derived exosomal miR-20b-5p, the expression patterns of exosomal miRNAs were concordant between plasma and serum, indicating the potential use of exosomal miRNAs as biomarkers.

CONCLUSION

We identified four plasma miRNAs and four serum miRNAs from the miR-106a-363 cluster as promising novel biomarkers for the diagnosis of BC.

Circulating myomiRs: a new class of biomarkers to monitor skeletal muscle in physiology and medicine

MicroRNAs (miRNA) are small non-coding RNAs that target mRNAs and are consequently involved in the post-transcriptional regulation of gene expression. Some miRNAs are ubiquitously expressed in tissue, while others are tissue-specific or tissue-enriched. miRNAs can be released by cells and are found in various biofluids, including serum and plasma. Thus, measuring miRNAs in the circulation may provide information on the originating tissue or cells. MyomiRs are described as striated muscle-specific or muscle-enriched miRNAs. Their circulating levels can be measured and have been proposed to be new biomarkers of physiological and pathological muscle processes. The aims of this review are to summarize the current knowledge of circulating myomiRs, to identify the types of information they can provide about skeletal muscle, and to determine how to apply that information in the fields of research and medicine.

Transcoronary concentration gradients of circulating microRNAs in heart failure

AIMS

Circulating levels of microRNAs (miRNAs) are emergent promising biomarkers for cardiovascular disease. Altered expression of miRNAs has been related to heart failure (HF) and cardiac remodelling. We measured the concentration gradients across the coronary circulation to assess their usefulness to diagnose HF of different aetiologies.

METHODS AND RESULTS

Circulating miRNAs were measured in plasma samples simultaneously obtained from the aorta and the coronary venous sinus in patients with non-ischaemic HF (NICM-HF, n = 23) ischaemic HF (ICM-HF, n = 41), and in control patients (n = 11). A differential modulation of circulating levels of miR-423, -34a, -21-3p, -126, -199 and -30a was found across the aetiology groups. Interestingly, a positive transcoronary gradient was found for miR-423 (P < 0.001) and miR-34a (P < 0.001) only in the ICM-HF group. On the contrary, a positive gradient was found for miR-21-3p (P < 0.001) and miR-30a (P = 0.030) only in the NICM-HF group. Finally, no significant variations were observed in the transcoronary gradient of miR-126 or miR-199.

CONCLUSIONS

The present findings suggest that circulating levels of miRNAs are differentially expressed in patients with HF of different aetiologies. The presence of a transcoronary concentration gradient suggests a selective release of miRNAs by the failing heart into the coronary circulation. The presence of aetiology-specific transcoronary concentration gradients in HF patients might provide important information to better understand their role in HF, and suggests they could be useful biomarkers to distinguish HF of different aetiologies.

Change in circulating microRNA profile of obese children indicates future risk of adult diabetes

PURPOSE

Childhood obesity increases susceptibility to type 2 diabetes (T2D) in adults. Circulating microRNAs (miRNAs) in serum have been proposed as potential diagnostic biomarkers, and they may contribute to the progression toward T2D. Here, we investigated the possibility of predicting the future risk of adult T2D in obese children by using circulating miRNAs.

BASIC PROCEDURES

We performed miRNA high-throughput sequencing to screen relevant circulating miRNAs in obese children. The expression patterns of targeted miRNAs were further explored in obese children and adults with T2D. To investigate the underlying contributions of these miRNAs to the development of T2D, we detected the impacts of the candidate miRNAs on preadipocyte proliferation, insulin secretion by pancreatic β-cell, and glucose uptake by skeletal muscle cells.

MAIN FINDINGS

Three miRNAs (miR-486, miR-146b and miR-15b), whose expression in the circulation was most dramatically augmented in obese children and adult T2D patients, were selected for further investigation. Of these 3 miRNAs, miR-486 was implicated in accelerating preadipocyte proliferation and myotube glucose intolerance, miR-146b and miR-15b were engaged in the suppression of high concentration glucose-induced pancreatic insulin secretion, and they all contributed to the pathological processes of obesity and T2D.

PRINCIPAL CONCLUSIONS

Our results provide a better understanding of the role of circulating miRNAs, particularly miR-486, miR-146b and miR-15b, in predicting the future risk of T2D in obese children.

Circulating microRNAs as Biomarkers for Pediatric Astrocytomas

BACKGROUND AND AIMS

Since MicroRNAs (miRNAs) are potent regulators of gene expression, their expression and function alterations are associated with different types of cancer, including pediatric astrocytoma. Since the secretion of miRNAs by tumors into corporal fluids has made it possible to identify biomarkers in cancer, their deter mination in pediatric astrocytoma is vital. In order to gain insight into the mechanisms controlled by miRNAs in these neoplasms, we tested the expression of miRNAs 130a, 145, 335, 1303, and let-7g-3p by qPCR in tumors and blood serum from pediatric patients with astrocytoma. The data was analyzed with the DIANA-miRPath v3.0 platform.

RESULTS

The data represented expression changes of all mirRNAs tested in both tumors and blood serum, which strongly suggest their use as circulating biomarkers for astrocytic tumors. The bioinformatic analysis -with DIANA-miRPath v3.0- showed the involvement of these miRNAs in extracellular matrix (ECM)-receptor interaction and proteoglycans in cancer, which control many hallmarks of cancer. In fact, the expression of the proteoglycan syndecan 4 (SDC4) and that of its biosynthetic enzymes, Exostosin Glycosyltransferase 1 (EXT1) and Xylosyltransferase 1 (XYLT1), were altered in pediatric astrocytoma.

CONCLUSIONS

Our results highlight the role of microRNAs in the biology of pediatric astrocytoma and demonstrated for the first time the potential use of some circulating microRNAs as non-invasive biomarkers for this type of tumors, particularly miRs 130a, 145, and 335.

Association of subcutaneous and visceral fat with circulating microRNAs in a middle-aged Japanese population

Purpose It has been demonstrated that circulating microRNA profiles are affected by physiological conditions. Several studies have demonstrated that microRNAs play important roles in the regulation of adiposity. However, few have investigated the relationship between circulating microRNAs and obesity, which has become a major public health problem worldwide. This study investigated the association between circulating microRNAs and obesity in a Japanese population. Methods Obesity parameters, such as subcutaneous and visceral fat adipose tissue, body fat percentage, and body mass index were assessed in a cross-sectional sample of 526 participants who attended health examinations in Yakumo, Japan. In addition, five circulating microRNAs (miR-20a, -21, -27a, -103a, and -320), which are involved in adipocyte proliferation and differentiation, were quantified using real-time polymerase chain reaction amplification. Results We compared the circulating microRNA concentrations in a percentile greater than 75th (high) with below the value (low) of subcutaneous adipose tissue, visceral fat adipose tissue, body mass index, and per cent body fat. For visceral fat adipose tissue, significant decrease in miR-320 expression was observed in high group. Also, for body mass index, significant change of miR-20a, -27a, 103a, and 320 expression level was observed in high group. Multiple linear regression analysis demonstrated that circulating levels of some microRNA such as miR-27a were significantly associated with subcutaneous adipose tissue, visceral fat adipose tissue, and body mass index. Conclusions Our findings support the need for further studies to determine whether such changes are consistent across different populations and whether the identified microRNAs may represent novel biomarkers to predict the susceptibility and progression of obesity-related disorders.

Comparison of Circulating miRNAs Expression Alterations in Matched Tissue and Plasma Samples During Colorectal Cancer Progression

MicroRNAs (miRNAs) have been found to play a critical role in colorectal adenoma-carcinoma sequence. MiRNA-specific high-throughput arrays became available to detect promising miRNA expression alterations even in biological fluids, such as plasma samples, where miRNAs are stable. The purpose of this study was to identify circulating miRNAs showing altered expression between normal colonic (N), tubular adenoma (ADT), tubulovillous adenoma (ADTV) and colorectal cancer (CRC) matched plasma and tissue samples. Sixteen peripheral plasma and matched tissue biopsy samples (N n = 4; ADT n = 4; ADTV n = 4; CRC n = 4) were selected, and total RNA including miRNA fraction was isolated. MiRNAs from plasma samples were extracted using QIAamp Circulating Nucleic Acid Kit (Qiagen). Matched tissue-plasma miRNA microarray experiments were conducted by GeneChip® miRNA 3.0 Array (Affymetrix). RT-qPCR (microRNA Ready-to-use PCR Human Panel I + II; Exiqon) was used for validation. Characteristic miRNA expression alterations were observed in comparison of AD and CRC groups (miR-149*, miR-3196, miR-4687) in plasma samples. In the N vs. CRC comparison, significant overexpression of miR-612, miR-1296, miR-933, miR-937 and miR-1207 was detected by RT-PCR (p < 0.05). Similar expression pattern of these miRNAs were observed using microarray in tissue pairs, as well. Although miRNAs were also found in circulatory system in a lower concentration compared to tissues, expression patterns slightly overlapped between tissue and plasma samples. Detected circulating miRNA alterations may originate not only from the primer tumor but from other cell types including immune cells.

Separation of Circulating MicroRNAs Using Apheresis in Patients With Systemic Lupus Erythematosus

MicroRNAs (miRNAs), which are important inhibitors of mRNA translation, participate in differentiation, migration, cell proliferation, and cell death. The pathology of miRNAs results in alterations in protein expression. Recently, miRNAs circulating in peripheral blood have been shown to control the synthesis and translation of proteins at distal sites after intake into local cells. A number of studies are currently being conducted to investigate how to use miRNAs in disease treatment, but no studies have attempted to alleviate disease by directly eliminating miRNAs from blood. Therefore, we examined whether the removal or reduction of circulating miRNAs with apheresis improved pathologies caused by miRNAs. After approval of the study by our medical school's ethics committee, we collected blood and separated plasma samples from three patients with systemic lupus erythematosus who were undergoing plasmapheresis at our hospital. Peripheral blood was collected before and after it was passed through a primary membrane, centrifuged, and used to extract circulating miRNAs. A comprehensive expression analysis was then performed with a miRNA array chip. The levels of expression of a large number of circulating miRNAs were measured in the plasma samples separated by the primary membranes from all 3 patients with systemic lupus erythematosus. We present the first report that circulating miRNAs in peripheral blood can be separated and possibly directly removed using membrane separation apheresis.

Circulating MicroRNA in patients with repaired tetralogy of Fallot

BACKGROUND

Emerging data suggest that heart-related microRNAs (miRs) may serve as circulating biomarkers of myocardial injury. We aimed to determine the circulating profile of miRs in patients with volume-overloaded right ventricles after repair of tetralogy (TOF).

MATERIALS AND METHODS

A total of 104 TOF patients and 70 controls were recruited. The study was conducted in two phases: (1) determination of circulating heart-related miRs described in left heart diseases (miR-1, miR-133a, miR-208a, miR-208b and miR423-5p) by quantitative real-time PCR in 49 patients and 30 controls and followed by validation in an independent cohort of 55 patients and 40 controls; (2) expression profiling of serum samples from eight patients and eight controls, followed by validation. Alteration in circulating miRNA expression was related to cardiac functional indices as assessed by 2D speckle tracking and 3D echocardiography.

RESULTS

No significant differences in serum levels of left heart-associated miRNAs were found between patients and controls. Of the candidate 19 miRNAs identified by profiling, upregulation of miR-99b and down-regulation of miR-766 were validated. However, no correlations were found between miRs levels and echo indices.

CONCLUSION

In young adults with repaired TOF and volume-overloaded right ventricles, circulating levels of miR-99b and miR-766, but not left heart-associated miRNAs, were significantly altered.