MicroRNA identification in plasma and serum: a new tool to diagnose and monitor diseases

Association of MiR-126 with soluble mesothelin-related peptides, a marker for malignant mesothelioma

Background

Improved detection methods for diagnosis of malignant pleural mesothelioma (MPM) are essential for early and reliable detection as well as treatment. Since recent data point to abnormal levels of microRNAs (miRNAs) in tumors, we hypothesized that a profile of deregulated miRNAs may be a marker of MPM and that the levels of specific miRNAs may be used for monitoring its progress.

Methods and Results

miRNAs isolated from fresh-frozen biopsies of MPM patients were tested for the expression of 88 types of miRNA involved in cancerogenesis. Most of the tested miRNAs were downregulated in the malignant tissues compared with the normal tissues. Of eight significantly downregulated, three miRNAs were assayed in cancerous tissue and adjacent non-cancerous tissue sample pairs collected from 27 formalin-fixed, paraffin-embedded MPM tissues by quantitative RT-PCR. Among the miRNAs tested, only miR-126 significantly remained downregulated in the malignant tissues. Furthermore, the performance of the selected miR-126 as biomarker was evaluated in serum samples of asbestos-exposed subjects and MPM patients and compared with controls. MiR-126 was not affected by asbestos exposure, whereas it was found strongly associated with VEGF serum levels. Levels of miR-126 in serum, and its levels in patients' serum in association with a specific marker of MPM, SMRPs, correlate with subjects at high risk to develop MPM.

Conclusions and Significance

We propose miR-126, in association with SMRPs, as a marker for early detection of MPM. The identification of tumor biomarkers used alone or, in particular, in combination could greatly facilitate the surveillance procedure for cohorts of subjects exposed to asbestos.

MicroRNA history: discovery, recent applications, and next frontiers

Since 1993, when the first small non-coding RNA was identified, our knowledge about microRNAs has grown exponentially. In this review, we focus on the main progress in this field and discuss the most important findings under a historical perspective. In addition, we examine microRNAs as markers of disease diagnosis and prognosis, and as new therapeutic targets.

Hsa-miR-34b is a plasma-stable microRNA that is elevated in pre-manifest Huntington's disease

Huntington's disease (HD) is a devastating, neurodegenerative condition, which lacks effective treatment. Normal Huntingtin (HTT) and mutant Huntingtin (mHTT) are expressed in multiple tissues and can alter transcription of microRNAs (miRs). Importantly, miRs are present in a bio-stable form in human peripheral blood plasma and have recently been shown to be useful biomarkers in other diseases. We therefore sought to identify potential miR biomarkers of HD that are present in, and have functional consequences for, neuronal and non-neuronal tissues. In a cell line over-expressing mHTT-Exon-1, miR microarray analysis was used to identify candidate miRs. We then examined their presence and bio-stability in control and HD plasma. We found that miR-34b is significantly elevated in response to mHTT-Exon-1, and its blockade alters the toxicity of mHTT-Exon-1 in vitro. We also show that miR-34b is detectable in plasma from small input volumes and is insensitive to freeze-thaw-induced RNA degradation. Interestingly, miR-34b is significantly elevated in plasma from HD gene carriers prior to symptom onset. This is the first study suggesting that plasma miRs might be used as biomarkers for HD.

Circulating plasma MiR-141 is a novel biomarker for metastatic colon cancer and predicts poor prognosis

Background

Colorectal cancer (CRC) remains one of the major cancer types and cancer related death worldwide. Sensitive, non-invasive biomarkers that can facilitate disease detection, staging and prediction of therapeutic outcome are highly desirable to improve survival rate and help to determine optimized treatment for CRC. The small non-coding RNAs, microRNAs (miRNAs), have recently been identified as critical regulators for various diseases including cancer and may represent a novel class of cancer biomarkers. The purpose of this study was to identify and validate circulating microRNAs in human plasma for use as such biomarkers in colon cancer.

Methodology/Principal Findings

By using quantitative reverse transcription-polymerase chain reaction, we found that circulating miR-141 was significantly associated with stage IV colon cancer in a cohort of 102 plasma samples. Receiver operating characteristic (ROC) analysis was used to evaluate the sensitivity and specificity of candidate plasma microRNA markers. We observed that combination of miR-141 and carcinoembryonic antigen (CEA), a widely used marker for CRC, further improved the accuracy of detection. These findings were validated in an independent cohort of 156 plasma samples collected at Tianjin, China. Furthermore, our analysis showed that high levels of plasma miR-141 predicted poor survival in both cohorts and that miR-141 was an independent prognostic factor for advanced colon cancer.

Conclusions/Significance

We propose that plasma miR-141 may represent a novel biomarker that complements CEA in detecting colon cancer with distant metastasis and that high levels of miR-141 in plasma were associated with poor prognosis.

Specific peripheral miRNA profiles for distinguishing lung cancer from COPD

Recently we reported differential miRNA signatures in blood cells of lung cancer patients and healthy controls. With the present study we wanted to investigate if miRNA blood signatures are also suited to differentiate lung cancer patients from COPD patients. We compared the expression of 863 human miRNAs in blood cells of lung cancer patients, COPD patients, and healthy controls. The miRNA pattern from patients with lung cancer and COPD were more similar to each other than to the healthy controls. However, we were able to discriminate lung cancer patients and COPD patients with 90.4% accuracy, 89.2% specificity, and 91.7% sensitivity. In total, 140 miRNAs were significant for the comparison COPD and controls, 61 miRNAs were significant for the comparison lung cancer and controls, and 14 miRNAs were significant for the comparison lung cancer and COPD. Screening target databases yielded over 400 putative targets for those 14 miRNAs. The predicted mRNA targets of three of the 14 miRNAs were significantly up-regulated in PBMCs of lung cancer patients compared to patients with non-malignant lung diseases. In conclusion, we showed that blood miRNA signatures are suitable to distinguish lung cancer from COPD.

Serum and urinary free microRNA level in patients with systemic lupus erythematosus

MicroRNAs circulating in body fluid have been suggested as biomarkers of various diseases. We studied the serum and urinary level of several miRNA species (miR-200 family, miR-205 and miR-192) in patients with systemic lupus erythematosus (SLE). We studied 40 SLE patients. Serum and urinary miRNA levels were determined and compared with that of healthy controls. The serum levels of miR-200a, miR-200b, miR-200c, miR-429, miR-205 and miR-192, and urinary miR-200a, miR-200c, miR-141, miR-429 and miR-192 of SLE patients were lower than those of controls. Glomerular filtration rate (GFR) correlated with serum miR-200b ( r = 0.411, p = 0.008), miR-200c ( r = 0.343, p = 0.030), miR-429 ( r = 0.347, p = 0.028), miR-205 ( r = 0.429, p = 0.006) and miR-192 ( r = 0.479, p = 0.002); proteinuria inversely correlated with serum miR-200a ( r = −0.375, p = 0.017) and miR-200c ( r = −0.347, p = 0.029). SLE disease activity index (SLEDAI) inversely correlated with serum miR-200a ( r = −0.376, p = 0.017). Serum miR-200b ( r = 0.455, p = 0.003) and miR-192 ( r = 0.589, p < 0.001) correlated with platelet count, while serum miR-205 correlated with red cell count ( r = 0.432, p = 0.005) and hematocrit ( r = 0.370, p = 0.019). These pilot results suggested that miRNA may take part in the pathogenesis of SLE. Further studies are needed to validate the role of serum miRNA as a biomarker of SLE.

Circulating miRNAs are correlated with tumor progression in prostate cancer

Circulating miRNAs have recently been indicated as practicable and promising biomarkers for noninvasive diagnosis in various tumor entities. However, cell-free miRNAs have not been found to correlate with clinicopathological variables in epithelial carcinomas. To learn more about the potential clinical relevance of circulating miRNAs in prostate cancer, we screened 667 miRNAs in serum samples from patients with metastatic (n = 7) and localized prostate cancer (n = 14). Various miRNAs were highly abundant in the sera of patients with metastatic disease, and five upregulated miRNAs (miRNA-375, miRNA-9*, miRNA-141, miRNA-200b and miRNA-516a-3p) were selected for further validation. In the first validation study (n = 45), selected miRNAs were analyzed in a prospectively collected serum set taken from different prostate cancer risk groups. Most of the selected miRNAs were significantly correlated with adverse risk factors when different clinicopathological variables were analyzed. Circulating miRNA-375 and miRNA-141 turned out to be the most pronounced markers for high-risk tumors. Their levels also correlated with high Gleason score or lymph-node positive status in a second independent validation study (n = 71). In addition, the expression levels of miRNA-375 and miRNA-141 were monitored in 72 prostate tissue samples (36 tumor vs. 36 benign). Both miRNAs were highly expressed in all samples and significantly upregulated in the tumors compared to normal tissues. Overall, our observations suggest that miRNA-375 and miRNA-141 expression is enhanced in prostate cancer specimens and their release into the blood is further associated with advanced cancer disease.

Potential role of maternal serum microRNAs as a biomarker for fetal congenital heart defects

Congenital heart defects (CHD) are the most common form of major birth defect, affecting almost 1% of live births. These defects place a significant economic burden on the National Health Service and on the psychological wellbeing of affected families. The early screening and identification of neonates with CHD could reduce morbidity and mortality by allowing proactive medical treatment and parental counseling about options during pregnancy, including termination. Fetal echocardiography is the principal screening tool for the identification of CHD, but its accuracy mainly depends on the skill and experience of the operator. Various biomarkers of screening for fetal CHD are currently available, such as nuchal translucency (NT), β-hCG and PAPP-A; however, these are non-specific indexes with high incidences of false positive results. Certain specific microRNAs (miRNAs) of cardiogenesis have been identified, which correlate positively with placental miRNA expression. These miRNAs of placental origin can be detected in maternal peripheral blood. Therefore, we postulate that these maternal serum miRNAs may be a potential biomarker for fetal CHD.

Serum microRNAs as non-invasive biomarkers for cancer

Human serum and other body fluids are rich resources for the identification of novel biomarkers, which can be measured in routine clinical diagnosis. microRNAs are small non-coding RNA molecules, which have an important function in regulating RNA stability and gene expression. The deregulation of microRNAs has been linked to cancer development and tumor progression. Recently, it has been reported that serum and other body fluids contain sufficiently stable microRNA signatures. Thus, the profiles of circulating microRNAs have been explored in a variety of studies aiming at the identification of novel non-invasive biomarkers.

In this review, we discuss recent findings indicating that circulating microRNAs are useful as non-invasive biomarkers for different tumor types. Additionally, we summarize the knowledge about the mechanism of microRNA release and the putative functional roles of circulating microRNAs. Although several challenges remain to be addressed, circulating microRNAs have the potential to be useful for the diagnosis and prognosis of cancer diseases.

Serum microRNAs as non-invasive biomarkers for cancer

Human serum and other body fluids are rich resources for the identification of novel biomarkers, which can be measured in routine clinical diagnosis. microRNAs are small non-coding RNA molecules, which have an important function in regulating RNA stability and gene expression. The deregulation of microRNAs has been linked to cancer development and tumor progression. Recently, it has been reported that serum and other body fluids contain sufficiently stable microRNA signatures. Thus, the profiles of circulating microRNAs have been explored in a variety of studies aiming at the identification of novel non-invasive biomarkers. In this review, we discuss recent findings indicating that circulating microRNAs are useful as non-invasive biomarkers for different tumor types. Additionally, we summarize the knowledge about the mechanism of microRNA release and the putative functional roles of circulating microRNAs. Although several challenges remain to be addressed, circulating microRNAs have the potential to be useful for the diagnosis and prognosis of cancer diseases.

Human traumatic brain injury alters plasma microRNA levels

Circulating microRNAs (miRNAs) present in the serum/plasma are characteristically altered in many pathological conditions, and have been employed as diagnostic markers for specific diseases. We examined if plasma miRNA levels are altered in patients with traumatic brain injury (TBI) relative to matched healthy volunteers, and explored their potential for use as diagnostic TBI biomarkers. The plasma miRNA profiles from severe TBI patients (Glasgow Coma Scale [GCS] score ≤8) and age-, gender-, and race-matched healthy volunteers were compared by microarray analysis. Of the 108 miRNAs identified in healthy volunteer plasma, 52 were altered after severe TBI, including 33 with decreased and 19 with increased relative abundance. An additional 8 miRNAs were detected only in the TBI plasma. We used quantitative RT-PCR to determine if plasma miRNAs could identify TBI patients within the first 24 h post-injury. Receiver operating characteristic curve analysis indicated that miR-16, miR-92a, and miR-765 were good markers of severe TBI (0.89, 0.82, and 0.86 AUC values, respectively). Multiple logistic regression analysis revealed that combining these miRNAs markedly increased diagnostic accuracy (100% specificity and 100% sensitivity), compared to either healthy volunteers or orthopedic injury patients. In mild TBI patients (GCS score > 12), miR-765 levels were unchanged, while the plasma levels of miR-92a and miR-16 were significantly increased within the first 24 h of injury compared to healthy volunteers, and had AUC values of 0.78 and 0.82, respectively. Our results demonstrate that circulating miRNA levels are altered after TBI, providing a rich new source of potential molecular biomarkers. Plasma-derived miRNA biomarkers, used in combination with established clinical practices such as imaging, neurocognitive, and motor examinations, have the potential to improve TBI patient classification and possibly management.

MicroRNAs are mediators of androgen action in prostate and muscle

Androgen receptor (AR) function is critical for the development of male reproductive organs, muscle, bone and other tissues. Functionally impaired AR results in androgen insensitivity syndrome (AIS). The interaction between AR and microRNA (miR) signaling pathways was examined to understand the role of miRs in AR function. Reduction of androgen levels in Sprague-Dawley rats by castration inhibited the expression of a large set of miRs in prostate and muscle, which was reversed by treatment of castrated rats with 3 mg/day dihydrotestosterone (DHT) or selective androgen receptor modulators. Knockout of the miR processing enzyme, DICER, in LNCaP prostate cancer cells or tissue specifically in mice inhibited AR function leading to AIS. Since the only function of miRs is to bind to 3' UTR and inhibit translation of target genes, androgens might induce miRs to inhibit repressors of AR function. In concordance, knock-down of DICER in LNCaP cells and in tissues in mice induced the expression of corepressors, NCoR and SMRT. These studies demonstrate a feedback loop between miRs, corepressors and AR and the imperative role of miRs in AR function in non-cancerous androgen-responsive tissues.

Serum and Urinary Cell–free MiR-146a and MiR-155 in Patients with Systemic Lupus Erythematosus

Objective.

Recent studies showed that micro-RNA play important roles in the pathogenesis of autoimmune diseases. We studied the levels of miR-146a and miR-155 in the serum and urinary supernatant of patients with systemic lupus erythematosus (SLE).

Methods.

The serum and urinary supernatant levels of miR-146a and miR-155 were determined by real-time quantitative polymerase chain reaction in 40 patients with SLE and 30 healthy controls.

Results.

Compared to controls, serum miR-146a and miR-155 levels were lower, and the urinary level of miR-146a was higher, in SLE. Estimated glomerular filtration rate (eGFR) correlated with both serum miR-146a (r = 0.519, p = 0.001) and miR-155 (r = 0.384, p = 0.014). Serum miR-146a inversely correlated with proteinuria (r = −0.341, p = 0.031) and the SLE Disease Activity Index (r = −0.465, p = 0.003). Serum miR-146a and miR-155 levels also correlated with red blood cell count, platelet count, and lymphocyte count. After treatment with calcitriol for 6 months, serum miR-146a level of SLE patients increased significantly (p < 0.001), and its change inversely correlated with the level of calcium-phosphate product (r = −0.466, p = 0.003).

Conclusion.

The results suggested that serum miR-146a and miR-155 participate in the pathophysiology of SLE and might be used as biomarkers of SLE.

The microRNA spectrum in 12 body fluids

BACKGROUND

MicroRNAs (miRNAs) are small, noncoding RNAs that play an important role in regulating various biological processes through their interaction with cellular messenger RNAs. Extracellular miRNAs in serum, plasma, saliva, and urine have recently been shown to be associated with various pathological conditions including cancer.

METHODS

With the goal of assessing the distribution of miRNAs and demonstrating the potential use of miRNAs as biomarkers, we examined the presence of miRNAs in 12 human body fluids and urine samples from women in different stages of pregnancy or patients with different urothelial cancers. Using quantitative PCR, we conducted a global survey of the miRNA distribution in these fluids.

RESULTS

miRNAs were present in all fluids tested and showed distinct compositions in different fluid types. Several of the highly abundant miRNAs in these fluids were common among multiple fluid types, and some of the miRNAs were enriched in specific fluids. We also observed distinct miRNA patterns in the urine samples obtained from individuals with different physiopathological conditions.

CONCLUSIONS

MicroRNAs are ubiquitous in all the body fluid types tested. Fluid type-specific miRNAs may have functional roles associated with the surrounding tissues. In addition, the changes in miRNA spectra observed in the urine samples from patients with different urothelial conditions demonstrates the potential for using concentrations of specific miRNAs in body fluids as biomarkers for detecting and monitoring various physiopathological conditions.

Assessing the human immune system through blood transcriptomics

Blood is the pipeline of the immune system. Assessing changes in transcript abundance in blood on a genome-wide scale affords a comprehensive view of the status of the immune system in health and disease. This review summarizes the work that has used this approach to identify therapeutic targets and biomarker signatures in the field of autoimmunity and infectious disease. Recent technological and methodological advances that will carry the blood transcriptome research field forward are also discussed.

Incorporating zebrafish omics into chemical biology and toxicology

In this communication, we describe the general aspects of omics approaches for analyses of transcriptome, proteome, and metabolome, and how they can be strategically incorporated into chemical screening and perturbation studies using the zebrafish system. Pharmacological efficacy and selectivity of chemicals can be evaluated based on chemical-induced phenotypic effects; however, phenotypic observation has limitations in identifying mechanistic action of chemicals. We suggest adapting gene-expression-based high-throughput screening as a complementary strategy to zebrafish-phenotype-based screening for mechanistic insights about the mode of action and toxicity of a chemical, large-scale predictive applications and comparative analysis of chemical-induced omics signatures, which are useful to identify conserved biological responses, signaling pathways, and biomarkers. The potential mechanistic, predictive, and comparative applications of omics approaches can be implemented in the zebrafish system. Examples of these using the omics approaches in zebrafish, including data of ours and others, are presented and discussed. Omics also facilitates the translatability of zebrafish studies across species through comparison of conserved chemical-induced responses. This review is intended to update interested readers with the current omics approaches that have been applied in chemical studies on zebrafish and their potential in enhancing discovery in chemical biology.

Fecal MicroRNAs as novel biomarkers for colon cancer screening

INTRODUCTION

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths, but currently available noninvasive screening programs have achieved only a modest decrease in mortality. MicroRNAs (miRNA) play an important role in a wide array of biological processes and are commonly dysregulated in neoplasia. We aimed to evaluate the feasibility of fecal miRNAs as biomarkers for colorectal neoplasia screening.

MATERIALS AND METHODS

Total RNA was extracted from freshly collected stool samples from 8 healthy volunteers and 29 samples collected via fecal occult blood testing from subjects with normal colonoscopies, colon adenomas, and CRCs. miRNA expression analyses were done with TaqMan quantitative reverse transcription-PCR for a subset of miRNAs. Illumina miRNA microarray profiling was done to evaluate the differences in expression patterns between normal colonic mucosa tissues and stool samples from healthy subjects.

RESULTS

We efficiently extracted miRNAs from stool specimens using our developed protocol. Data from independent experiments showed high reproducibility for miRNA extraction and expression. miRNA expression patterns were similar in stool specimens among healthy volunteers, and reproducible in stool samples that were collected serially in time from the same individuals. miRNA expression profiles from 29 patients showed higher expression of miR-21 and miR-106a in patients with adenomas and CRCs compared with individuals free of colorectal neoplasia.

CONCLUSION

Our data indicate that miRNAs could be extracted from stool easily and reproducibly. The stools of patients with colorectal neoplasms have unique and identifiable patterns of miRNA expression.

IMPACT

Fecal miRNAs may be an excellent candidate for the development of a noninvasive screening test for colorectal neoplasms.

High-throughput miRNA profiling of human melanoma blood samples

Background

MicroRNA (miRNA) signatures are not only found in cancer tissue but also in blood of cancer patients. Specifically, miRNA detection in blood offers the prospect of a non-invasive analysis tool.

Methods

Using a microarray based approach we screened almost 900 human miRNAs to detect miRNAs that are deregulated in their expression in blood cells of melanoma patients. We analyzed 55 blood samples, including 20 samples of healthy individuals, 24 samples of melanoma patients as test set, and 11 samples of melanoma patients as independent validation set.

Results

A hypothesis test based approch detected 51 differentially regulated miRNAs, including 21 miRNAs that were downregulated in blood cells of melanoma patients and 30 miRNAs that were upregulated in blood cells of melanoma patients as compared to blood cells of healthy controls. The tets set and the independent validation set of the melanoma samples showed a high correlation of fold changes (0.81). Applying hierarchical clustering and principal component analysis we found that blood samples of melanoma patients and healthy individuals can be well differentiated from each other based on miRNA expression analysis. Using a subset of 16 significant deregulated miRNAs, we were able to reach a classification accuracy of 97.4%, a specificity of 95% and a sensitivity of 98.9% by supervised analysis. MiRNA microarray data were validated by qRT-PCR.

Conclusions

Our study provides strong evidence for miRNA expression signatures of blood cells as useful biomarkers for melanoma.

Small molecules with big effects: the role of the microRNAome in cancer and carcinogenesis

Small non-coding RNAs-microRNAs, are potent negative regulators of gene expression. MicroRNAs are involved in multiple biological processes, metabolic regulation, including cell proliferation, differentiation, and programmed cell death. Since the dysregulation of these processes is a hallmark of cancer, microRNAs can be viewed as major contributors to the pathogenesis of cancer, including initiation and progression of cancer. This review focuses on microRNA biogenesis and function, and their role in cancer, metastasis, drug resistance, and tumorigenesis.

Epidermal growth factor receptor tyrosine kinase inhibitors as first-line treatment in advanced nonsmall-cell lung cancer

PURPOSE OF REVIEW

Classic activating mutations in the form of deletions in exon 19 or a missense mutation L858R in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) predict dramatic responses to EGFR tyrosine kinase inhibitors such as gefitinib and erlotinib. We review here the clinical benefits of targeted therapy with erlotinib and gefitinib in white and Asian nonsmall-cell lung cancer patients.

RECENT FINDINGS

Two separate analyses of pooled data from small phase II prospective studies show that therapy with gefitinib and erlotinib induces responses in over 70% of nonsmall-cell lung cancer patients harboring classic EGFR mutations, with progression-free survival ranging from 9 to 13 months and median survival of around 23 months. Two separate studies in white and Asian patients have recently confirmed that these subgroups of patients attain response rates of 70% with erlotinib and gefitinib, including complete responses, progression-free survival of up to 14 months, and median survival of up to 27 months. The serial monitoring of EGFR mutations in the blood will permit the assessment of molecular responses and be an important tool for the surveillance of clinical progression.

SUMMARY

Nonsmall-cell lung cancer with EGFR mutations constitute a new entity with a unique opportunity for further refinement of different genetic subgroups among patients with EGFR mutations, requiring different personalized treatment strategies. Despite the impressive outcomes attained with EGFR tyrosine kinase inhibitors, patients with EGFR mutations at present require continuous treatment, and only a fraction of these patients will reach sustainable long-term survival.

A translational study of circulating cell-free microRNA-1 in acute myocardial infarction

miRNAs (microRNAs) participate in many diseases including cardiovascular disease. In contrast with our original hypothesis, miRNAs exist in circulating blood and are relatively stable due to binding with other materials. The aim of the present translational study is to establish a method of determining the absolute amount of an miRNA in blood and to determine the potential applications of circulating cell-free miR-1 (microRNA-1) in AMI (acute myocardial infarction). The results revealed that miR-1 is the most abundant miRNA in the heart and is also a heart- and muscle-specific miRNA. In a cardiac cell necrosis model induced by Triton X-100 in vitro, we found that cardiac miR-1 can be released into the culture medium and is stable at least for 24 h. In a rat model of AMI induced by coronary ligation, we found that serum miR-1 is quickly increased after AMI with a peak at 6 h, in which an increase in miR-1 of over 200-fold was demonstrated. The miR-1 level returned to basal levels at 3 days after AMI. Moreover, the serum miR-1 level in rats with AMI had a strong positive correlation with myocardial infarct size. To verify further the relationship between myocardial size and miR-1 level, an IP (ischaemic preconditioning) model was used. The results showed that IP significantly reduced circulating miR-1 levels and myocardial infract size induced by I/R (ischaemia/reperfusion) injury. Finally, the levels of circulating cell-free miR-1 were significantly increased in patients with AMI and had a positive correlation with serum CK-MB (creatine kinase-MB) levels. In conclusion, the results suggest that serum miR-1 could be a novel sensitive diagnostic biomarker for AMI.

MicroRNAs as biomarkers for CNS cancer and other disorders

The use of miRNAs as biomarkers has gained growing interest in the last few years. Their role in regulating a great variety of targets and, as a consequence, multiple pathways, makes their use in diagnostics a powerful tool to be exploited for early detection of disease, risk assessment and prognosis and for the design of innovative therapeutic strategies. While still not fully validated, profiling of blood cells, exosomes or body fluid miRNAs would represent a tremendous and promising advance in non-invasive diagnostics of CNS disorders. A major challenge is represented by technological aspects of miRNA detection and discovery aiming to genome-wide high throughput, sensitive and accurate analysis. Although there is much to be learned in the field, this review will highlight the potential role of miRNA as a new class of biomarkers in several CNS disorders, including neurodegenerative diseases such as Alzheimer, Huntington and Parkinson diseases, schizophrenia and autism as well as different types of cancer (e.g. gliomas and medulloblastomas).

Biomarkers for drug-induced liver injury

Of the estimated 10,000 documented human drugs, more than 1000 have been associated with drug-induced liver injury (DILI), although causality has not always been established clearly. Numerous biomarkers for DILI have been explored, but less than ten are adopted or qualified as valid by the US FDA. The biomarkers for DILI are individual or a panel of proteins, nucleic acids or metabolites from various sources, such as the liver, blood and urine. While most DILI biomarkers are drug independent, some possibly 'drug-specific' DILIs have been explored, but specificity and sensitivity of both types need to be improved for the diagnosis of DILI during drug development and in clinical practice. Novel approaches for DILI biomarkers have been actively investigated recently, but produced mainly animal-based biomarkers, which are possibly useful for drug development, but are not suitable or have not been validated for clinical applications. This review summarizes the current practice and future perspectives for DILI biomarkers.

MicroRNAs in cardiovascular diseases: biology and potential clinical applications

Cardiovascular diseases represent one of the major causes for increasing rates of human morbidity and mortality across the world. This reinforces the necessity for the development of novel diagnostics and therapies for the early identification and cure of heart diseases. MicroRNAs are evolutionarily conserved small regulatory non-coding RNAs that regulate the expression of large number of genes. They are involved in several cellular pathophysiological pathways and have been shown to play a significant role in the pathogenesis of many disease states. Recent studies have correlated dysregulated miRNA expressions to diseased hearts and also shown the relevance of miRNA in growth, development, function, and stress responsiveness of the heart. The possibility of exploiting miRNAs to develop diagnostic markers or manipulating them to obtain therapeutic effects is very attractive since they have very specific targets in a particular cellular pathway. In this review we will summarize the role played by miRNAs in the heart and discuss the scope of utilizing miRNA-based strategies in the clinics for the benefit of mankind.

Serum miR-146a and miR-223 as potential new biomarkers for sepsis

OBJECTIVE

Current biomarkers cannot completely distinguish sepsis from systemic inflammatory response syndrome (SIRS) caused by other non-infectious diseases. Circulating microRNAs (miRNAs) are promising biomarkers for several diseases, but their correlation with sepsis is not totally clarified.

METHODS

Seven miRNAs related to inflammation or infection were included in the present study. Serum miRNA expression was investigated in 50 patients diagnosed with sepsis, 30 patients with SIRS and 20 healthy controls to evaluate the diagnostic and prognostic value. Expression levels of serum miRNAs were determined by quantitative PCR using the Qiagen miScript system. Serum CRP and IL-6 levels were determined by enzyme linked immunosorbent assay.

RESULTS

Serum miR-146a and miR-223 were significantly reduced in septic patients compared with SIRS patients and healthy controls. The areas under the receiver operating characteristic curve of miR-146a, miR-223 and IL-6 were 0.858, 0.804 and 0.785, respectively.

CONCLUSION

Serum miR-146a and miR-223 might serve as new biomarkers for sepsis with high specificity and sensitivity. (ClinicalTrials.gov number, NCT00862290.).

Non-coding RNAs: regulators of disease

For 50 years the term 'gene' has been synonymous with regions of the genome encoding mRNAs that are translated into protein. However, recent genome-wide studies have shown that the human genome is pervasively transcribed and produces many thousands of regulatory non-protein-coding RNAs (ncRNAs), including microRNAs, small interfering RNAs, PIWI-interacting RNAs and various classes of long ncRNAs. It is now clear that these RNAs fulfil critical roles as transcriptional and post-transcriptional regulators and as guides of chromatin-modifying complexes. Here we review the biology of ncRNAs, focusing on the fundamental mechanisms by which ncRNAs facilitate normal development and physiology and, when dysfunctional, underpin disease. We also discuss evidence that intergenic regions associated with complex diseases express ncRNAs, as well as the potential use of ncRNAs as diagnostic markers and therapeutic targets. Taken together, these observations emphasize the need to move beyond the confines of protein-coding genes and highlight the fact that continued investigation of ncRNA biogenesis and function will be necessary for a comprehensive understanding of human disease.

MicroRNA fingerprints identify miR-150 as a plasma prognostic marker in patients with sepsis

BACKGROUND

The physiopathology of sepsis continues to be poorly understood, and despite recent advances in its management, sepsis is still a life-threatening condition with a poor outcome. If new diagnostic markers related to sepsis pathogenesis will be identified, new specific therapies might be developed and mortality reduced. Small regulatory non-coding RNAs, microRNAs (miRNAs), were recently linked to various diseases; the aim of our prospective study was to identify miRNAs that can differentiate patients with early-stage sepsis from healthy controls and to determine if miRNA levels correlate with the severity assessed by the Sequential Organ Failure Assessment (SOFA) score.

METHODOLOGY/PRINCIPAL FINDINGS

By using genome-wide miRNA profiling by microarray in peripheral blood leukocytes, we found that miR-150, miR-182, miR-342-5p, and miR-486 expression profiles differentiated sepsis patients from healthy controls. We also proved by quantitative reverse transcription-polymerase chain reaction that miR-150 levels were significantly reduced in plasma samples of sepsis patients and correlated with the level of disease severity measured by the SOFA score, but were independent of the white blood counts (WBC). We found that plasma levels of tumor necrosis factor alpha, interleukin-10, and interleukin-18, all genes with sequence complementarity to miR-150, were negatively correlated with the plasma levels of this miRNA. Furthermore, we identified that the plasma levels ratio for miR-150/interleukin-18 can be used for assessing the severity of the sepsis.

CONCLUSIONS/SIGNIFICANCE

We propose that miR-150 levels in both leukocytes and plasma correlate with the aggressiveness of sepsis and can be used as a marker of early sepsis. Furthermore, we envision miR-150 restoration as a future therapeutic option in sepsis patients.