Circulating microRNA-21 as a novel biomarker for hepatocellular carcinoma

Plasma miR-15b-5p, miR-338-5p, and miR-764 as Biomarkers for Hepatocellular Carcinoma

Background

Recently, increasing research evidence indicates that miRNA plays important roles in oncogenesis of hepatocellular carcinoma (HCC). The objective of this study was to investigate the potential of plasma miRNAs as biomarkers for HCC determination.

Material/Methods

This trial included 4 phases: (i) miRNAs in tumor tissues were screened with a miRNA array for determining candidate miRNAs. (ii) Candidate miRNAs were measured by RT-qPCR in plasma of 10 HCC patients before and after surgery (7–10 days) for target miRNAs that displayed a pattern of postoperative decrease. (iii) Plasma levels of target miRNAs in 37 HCC patients, 29 cirrhosis patients, and 31 healthy controls were measured by RT-qPCR for determining potential biomarkers. (iv) The powers of biomarkers for differentiating HCC were validated and the correlations with clinicopathological variables of HCC patients were analyzed.

Results

miRNA array demonstrated an abnormal expression of 92 miRNAs in tumor tissues compared to adjacent non-tumor tissues. Of those molecules with an over-expressed level in tumor tissues and preoperative plasmas, a decrease in postoperative plasma was observed in miR-15b-5p, miR-338-5p, and miR-764. Plasma levels of these miRNAs in HCC patients were higher than in the other 2 groups (P<0.05). Receiver-operator characteristic (ROC) curve analyses suggested these plasma miRNAs could be useful biomarkers for determining HCC. miR-338-5p yielded an area under the ROC curve (AUC) of 0.799 (74.5% sensitivity and 82.8% specificity) and 0.909 (72.3% sensitivity and 99.68% specificity) to discriminate HCC patients from cirrhosis patients and healthy controls, respectively. The expression level of miR-338-5p was negatively correlated with the level of AFP (r=−0.306, P=0.036), and the expression level of miR-764 was positively correlated with the tumor size (r=0.371, P=0.01).

Conclusions

Circulating miR-15b-5p, miR-338-5p, and miR-764 may be biomarkers for diagnosis of HCC.

Potential Role of Circulating microRNA-21 for Hepatocellular Carcinoma Diagnosis: A Meta-Analysis

BACKGROUND

Circulating microRNA-21 (miR-21) is known to be aberrantly expressed in hepatocellular carcinoma (HCC) patients, and this implies that microRNA-21 is a promising and novel indicator of HCC. However, a systematic evaluation of the performance of microRNA-21 as a diagnostic marker for HCC has yet to be conducted. Therefore, the test performance of circulating miR-21 for HCC was assessed in this study.

METHODS

Three common international databases and a Chinese electronic database were used to search for literature on the diagnostic accuracy of microRNA-21 for HCC. The pooled results included the sensitivity and specificity of microRNA-21 for HCC detection and were analyzed with a random effect model. The area under summary receiver operating characteristic curve (AUC) was used to estimate overall test performance.

RESULTS

A total of 339 HCC patients and 338 controls without HCC from four published studies were eligible for the meta-analysis and included in our study. The test performance of circulating miR-21 in HCC detection was assessed with the summary estimates of sensitivity and specificity, which were 81.2% (95% CI: 70.8% to 88.4%) and 84.8% (95% CI: 75.1% to 91.2%), respectively. The value of AUC was 0.90 (95% CI: 0.87 to 0.92). Significant inter-study heterogeneity was detected by our analysis, and sub-group analyses suggested that the type of control group was probably a source of heterogeneity.

CONCLUSIONS

Our current findings suggested that circulating miR-21 can serve as a potential co-biomarker for early-stage HCC diagnosis. Thorough large-scale studies are needed to confirm the generalizability of our findings.

A serum microRNA classifier for early detection of hepatocellular carcinoma: a multicentre, retrospective, longitudinal biomarker identification study with a nested case-control study

BACKGROUND

The ability of circulating microRNAs (miRNAs) to detect preclinical hepatocellular carcinoma has not yet been reported. We aimed to identify and assess a serum miRNA combination that could detect the presence of clinical and preclinical hepatocellular carcinoma in at-risk patients.

METHODS

We did a three-stage study that included healthy controls, inactive HBsAg carriers, individuals with chronic hepatitis B, individuals with hepatitis B-induced liver cirrhosis, and patients with diagnosed hepatocellular carcinoma from four hospitals in China. We used array analysis and quantitative PCR to identify 19 candidate serum miRNAs that were increased in six patients with hepatocellular carcinoma compared with eight control patients with chronic hepatitis B. Using a training cohort of patients with hepatocellular carcinoma and controls, we built a serum miRNA classifier to detect hepatocellular carcinoma. We then validated the classifiers' ability in two independent cohorts of patients and controls. We also established the classifiers' ability to predict preclinical hepatocellular carcinoma in a nested case-control study with sera prospectively collected from patients with hepatocellular carcinoma before clinical diagnosis and from matched individuals with hepatitis B who did not develop cancer from the same surveillance programme. We used the sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) to evaluate diagnostic performance, and compared the miRNA classifier with α-fetoprotein at a cutoff of 20 ng/mL (AFP20).

FINDINGS

Between Aug 1, 2009, and Aug 31, 2013, we recruited 257 participants to the training cohort, and 352 and 139 participants to the two independent validation cohorts. In the third validation cohort, 27 patients with hepatocellular carcinoma and 135 matched controls were included in the nested case-control study, which ran from Aug 1, 2009, to Aug 31, 2014. We identified a miRNA classifier (Cmi) containing seven differentially expressed miRNAs (miR-29a, miR-29c, miR-133a, miR-143, miR-145, miR-192, and miR-505) that could detect hepatocellular carcinoma. Cmi showed higher accuracy than AFP20 to distinguish individuals with hepatocellular carcinoma from controls in the validation cohorts, but not in the training cohort (AUC 0·826 [95% CI 0·771-0·880] vs 0·814 [0·756-0·872], p=0·72 in the training cohort; 0·817 [0·769-0·865] vs 0·709 [0·653-0·765], p=0·00076 in validation cohort 1; and 0·884 [0·818-0·951] vs 0·796 [0·706-0·886], p=0·042 for validation cohort 2). In all four cohorts, Cmi had higher sensitivity (range 70·4-85·7%) than did AFP20 (40·7-69·4%) to detect hepatocellular carcinoma at the time of diagnosis, whereas its specificity (80·0-91·1%) was similar to that of AFP20 (84·9-100%). In the nested case-control study, sensitivity of Cmi to detect hepatocellular carcinoma was 29·6% (eight of 27 cases) 12 months before clinical diagnosis, 48·1% (n=13) 9 months before clinical diagnosis, 48·1% (n=13) 6 months before clinical diagnosis, and 55·6% (n=15) 3 months before clinical diagnosis, whereas sensitivity of AFP20 was only 7·4% (n=2), 11·1% (n=3), 18·5% (n=5), and 22·2% (n=6) at the corresponding timepoints (p=0·036, p=0·0030, p=0·021, p=0·012, respectively). Cmi had a larger AUC than did AFP20 to identify small-size (AUC 0·833 [0·782-0·883] vs 0·727 [0·664-0·792], p=0·0018) and early-stage (AUC 0·824 [0·781-0·868] vs 0·754 [0·702-0·806], p=0·015) hepatocellular carcinoma and could also detect α-fetoprotein-negative (AUC 0·825 [0·779-0·871]) hepatocellular carcinoma.

INTERPRETATION

Cmi is a potential biomarker for hepatocellular carcinoma, and can identify small-size, early-stage, and α-fetoprotein-negative hepatocellular carcinoma in patients at risk. The miRNA classifier could be valuable to detect preclinical hepatocellular carcinoma, providing patients with a chance of curative resection and longer survival.

FUNDING

National Key Basic Research Program, National Science and Technology Major Project, National Natural Science Foundation of China.

Prognostic Value and Clinicopathology Significance of MicroRNA-200c Expression in Cancer: A Meta-Analysis

MiR-200c has been shown to be related to cancer formation and progression. However, the prognostic and clinicopathologic significance of miR-200c expression in cancer remain inconclusive. We carried out this systematic review and meta-analysis to investigate the prognostic value of miR-200c expression in cancer. Pooled hazard ratios (HRs) of miR-200c for overall survival (OS) and progression-free survival (PFS) were calculated to measure the effective value of miR-200c expression on prognosis. The association between miR-200c expression and clinical significance was measured by odds ratios (ORs). Twenty-three studies were included in our meta-analysis. We found that miR-200c was not significantly correlated with OS (HR = 1.41, 95%Cl: 0.95-2.10; P = 0.09) and PFS (HR = 1.12, 95%Cl: 0.68-1.84; P = 0.67) in cancer. In our subgroup analysis, higher expression of miR-200c was significantly associated with poor OS in blood (HR = 2.10, 95%CI: 1.52-2.90, P<0.00001). Moreover, in clinicopathology analysis, miR-200c expression in blood was significantly associated with TNM stage, lymph node metastasis and distant metastasis. MiR-200c may have the potential to become a new blood biomarker to monitor cancer prognosis and progression.

Identification of circulating MicroRNAs as novel potential biomarkers for hepatocellular carcinoma detection: a systematic review and meta-analysis

BACKGROUND

MicroRNAs (miRNAs) in body fluids such as serum and plasma can be stably detected and used as potential biomarkers in hepatocellular carcinoma (HCC) diagnosis.

OBJECTIVE

To systematically evaluate circulating miRNAs from HCC expression profiling studies and to determine miRNA biomarkers for HCC detection.

METHODS

A systematic review and meta-analysis of published studies were carried out for comparing the circulating miRNA expressions between HCC patients and healthy people, hepatitis, or cirrhosis patients. A miRNA ranking system that considered the number of comparisons in agreement and total number of samples was used. Then the summary receiver-operating characteristic curve (sROC) results of the top miRNAs were combined to further evaluate their diagnostic value using Meta-disc 1.4.

RESULTS

In the 17 included studies, three circulating miRNAs (miR-21, miR-122, and miR-223) were repeatedly reported three times or more in both HCC patients vs. healthy controls and vs. other hepatitis or cirrhosis patients. In further analysis, the area under curve (AUC) of sROC for miR-21, miR-122 and miR-223 in discriminating HCC patients from healthy people are 0.9293, 0.8128, and 0.8597, respectively.

CONCLUSIONS

Circulating miR-21 has highest level of diagnostic efficiency among three miRNAs candidate biomarkers (miR-21, miR-122, and miR-223) for detection of HCC.

Differential expression of serum microRNAs in cirrhosis that evolve into hepatocellular carcinoma related to hepatitis B virus

Circulating microRNAs (miRNAs) exist stably in body fluids and are potential biomarkers for hepatocellular carcinoma (HCC). Twenty-five patients with cirrhosis that evolved into HCC, who were treated at The Third Hospital of Zhenjiang Affiliated to Jiangsu University between January 2005 and December 2012, were enrolled. In the discovery stage, 2 serum samples pooled from 3 cirrhosis and 3 HCC samples were subjected to deep sequencing. Subsequently, differential expression of miRNAs was validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in the serum samples from an independent cohort of 22 patients with cirrhosis and HCC. Twenty-two miRNAs showed a >2-fold upregulation (P<0.01), and 2 miRNAs showed a >2-fold downregulation (P<0.01) in the cirrhosis and HCC samples. Using the comparative Ct method, we calculated the 2-(ΔΔCt) for 40 candidate miRNAs in the sample sets. Eight of the 40 miRNAs demonstrated significantly differential expression levels between the disease categories. The miRNAs exhibiting differential expression were hsa-miR-122-5p, has-miR-199a-5p, hsa-miR-486-5p, has-miR-193b-5p, hsa-miR-206, has-miR-141-3p, has-miR-192-5p and has-miR-26a-5p. We identified the miRNAs differentially expressed in cirrhosis that evolved into hepatitis B virus-related HCC.

Biomarkers for hepatocellular carcinoma: diagnostic and therapeutic utility

Because of the high prevalence and associated-mortality of hepatocellular carcinoma (HCC), early diagnosis of the disease is vital for patient survival. In this regard, tumor size is one of the two main prognostic factors for surgical resection, which constitutes the only curative treatment for HCC along with liver transplantation. However, techniques for HCC surveillance and diagnosis that are currently used in clinical practice have certain limitations that may be inherent to the tumor development. Thus, it is important to continue efforts in the search for biomarkers that increase diagnostic accuracy for HCC. In this review, we focus on different biological sources of candidate biomarkers for HCC diagnosis. Although those biomarkers identified from biological samples obtained by noninvasive methods have greater diagnostic value, we have also considered those obtained from liver tissue because of their potential therapeutic value. To date, sorafenib is the only US Food and Drug Administration-approved antineoplastic for HCC. However, this therapeutic agent shows very low tumor response rates and frequently causes acquired resistance in HCC patients. We discuss the use of HCC biomarkers as therapeutic targets themselves, or as targets to increase sensitivity to sorafenib treatment.

miR-33a levels in hepatic and serum after chronic HBV-induced fibrosis

BACKGROUND

Chronic hepatitis B virus (HBV) infection, which can lead to hepatic disease, has become a critical national healthcare problem, and many people die each year as a result of HBV infection and its complications. Although microRNA-33a (miR-33a) is a novel modulator of lipid and cholesterol metabolism, the role of miR-33a in the hepatic fibrogenesis is still unknown. Here, we aimed to explore the roles and mechanisms of miR-33a in liver fibrosis.

METHODS

miR-33a expression in whole liver and serum samples was measured from chronic hepatitis B (CHB) patients by quantitative real-time PCR (qRT-PCR). In addition, different murine hepatic fibrosis models were produced to consolidate the results in human tissue. Human and murine primary liver fibrosis-associated cells were isolated and treated with transforming growth factor-β1 (TGF-β1).

RESULTS

miR-33a expression levels in liver tissue significantly increased with a fibrosis progression manner in the human liver. Furthermore, serum miR-33a levels associated positively with progressing process of hepatic fibrosis. miR-33a was in particular increased in hepatic stellate cells (HSC) than other liver fibrosis-associated cells. Stimulation of HSCs with TGF-β1 leads to a critical increase of miR-33a. Increasing miR-33a levels increased (whereas inhibiting miR-33a weakened) the activation role of TGF-β1 in LX-2 cells, which might be a potential mechanism through moderating Smad7 expression.

CONCLUSIONS

miR-33a may be a novel marker for HSC activation and hepatic fibrosis progress, suggesting a new therapeutic target in liver fibrosis.

MicroRNAs as diagnostic biomarkers for hepatocellular carcinoma: A meta-analysis

AIM: To perform a literature review and meta-analysis of the diagnostic accuracy of microRNAs (miRNAs) for HCC.

METHODS: We systematically searched the Cochrane Central Register of Controlled Trials, PubMed, MEDLINE, EMBASE, the Chinese Biomedical Literature Database, the China Academic Journals Full-text Database, and the Chinese Scientific Journals Database for potential studies till October 2014. Studies were included and excluded according to inclusion and exclusion criteria. Meta-analysis was then performed to evaluate the overall diagnostic performance of miRNAs.

RESULTS: A total of 676 studies were retrieved, of which 11 were finally included in this meta-analysis. The range of the diagnostic sensitivity of miRNAs for HCC was 72%-98%, pooled sensitivity was 85%; specificity was 76%-100%, pooled specificity was 89%; positive likelihood ratio was 3.52-97.45, pooled positive likelihood ratio was 7.20; negative likelihood ratio was 0.02-0.57, pooled negative likelihood ratio was 0.18; and diagnostic odds ratio was 13.14-2646.00, pooled diagnostic odds ratio was 51.09.

CONCLUSION: MiRNAs have a relatively high accuracy in identifying HCC.

Circulating microRNAs as biomarkers in hepatocellular carcinoma screening: a validation set from China

Hepatocellular carcinoma (HCC) is a global public health concern. Current diagnostic methods show poor performance in early-stage HCC detection. Accumulating evidences revealed the great potential of microRNAs (miRNAs) as noninvasive biomarkers in HCC detection. In this study, we examined the diagnostic performance of serum miR-10b, miR-106b, and miR-181a for HCC screening in China. Furthermore, a systematic review of previous related studies was conducted to confirm our results. One hundred eight participants including 27 HCC patients, 31 chronic liver disease (CLD) patients, and 50 healthy people were recruited in this study. Blood specimen was drawn from each participant to extract serum miRNAs. Statistical analyses were performed to assess the 3 miRNAs levels in HCC, CLD patients, and normal controls. A meta-analysis was conducted to further assess the diagnostic value of miRNAs in HCC detection based on previous studies. All these miRNAs (miR-10b, miR-181a, miR-106b) could well discriminate HCC patients from normal controls, with area under the receiver-operating characteristic curve (AUC) values of 0.85 (95% confidence interval [CI]: 0.76-0.94), 0.82 (95% CI: 0.72-0.91), and 0.89 (95% CI: 0.81-0.97), respectively. In addition, these miRNAs could distinguish HCC cases from CLD controls with a medium accuracy. However, the ability of these miRNAs in differentiating CLD patients from normal controls was not satisfactory. Panel of these miRNAs displayed a better performance compared with single miRNA assay, with AUC values of 0.94 (95% CI: 0.89-0.99) in discriminating HCC patients from normal controls and 0.91 (95% CI: 0.80-0.97) in discriminating HCC patients from CLD controls. Results of meta-analysis of previous studies combined with the current study suggested that circulating miRNAs could well differentiate HCC from normal controls, with AUC values of 0.86 (95% CI: 0.82-0.89) for single miRNA assay and 0.94 (95% CI: 0.91-0.96) for miRNA panel assay. Serum miR-10b, miR-106b, and miR-181a have great potential to serve as accurate and noninvasive biomarkers for HCC preliminary screening. Meta-analysis of previous studies combined with current study further confirmed that circulating miRNAs could play an important role in HCC detection. Further large-scale studies are needed to confirm the clinical significance of circulating miRNAs in HCC screening.

Current biomarkers for hepatocellular carcinoma: Surveillance, diagnosis and prediction of prognosis

Biomarkers for surveillance, diagnosis and prediction of prognosis in patients with hepatocellular carcinoma (HCC) are currently not ready for introduction into clinical practice because of limited sensitivity and specificity. Especially for the early detection of small HCC novel biomarkers are needed to improve the current effectiveness of screening performed by ultrasound. The use of high-throughput technologies in hepatocellular research allows to identify molecules involved in the complex pathways in hepatocarcinogenesis. Several invasive and non-invasive biomarkers have been identified already and have been evaluated in different clinical settings. Gene signatures with prognostic potential have been identified by gene expression profiling from tumor tissue. However, a single "all-in-one" biomarker that fits all-surveillance, diagnosis, prediction of prognosis-has not been found so far. The future of biomarkers most probably lies in a combination of non-invasive biomarkers, imaging and clinical parameters in a surveillance setting. Molecular profiling of tumorous and non-tumorous liver tissue may allow a prediction of prognosis for the individual patient and hopefully clear the way for individual treatment approaches. This article gives an overview on current developments in biomarker research in HCC with a focus on currently available and novel biomarkers, in particular on microRNA.

Different normalization strategies might cause inconsistent variation in circulating microRNAs in patients with hepatocellular carcinoma

BACKGROUND

Circulating microRNA (miRNA) are promising biomarkers for diagnosing and prognosticating numerous diseases. Reports have demonstrated controversial or even contradictory conclusions in studies on circulating microRNA. This study aimed to evaluate the potential bias of using different reference genes for analyzing circulating microRNAs in the same malignant digestive diseases.

MATERIAL AND METHODS

We measured plasma concentrations of U6-snRNA, let-7a, miRNA-21, miRNA-106a, miRNA-155, miRNA-219, miRNA-221, and miRNA-16 in patients with hepatocellular carcinoma (HCC), gastric carcinoma (GC), hepatic cirrhosis, hepatitis B, and healthy volunteers using quantitative real-time polymerase chain reaction (qPCR). The GeNorm, Normfinder, BestKeeper, and Comparative ΔCq algorithms integrated in RefFinder were used to screen the most suitable reference genes from the candidates. The 4 commonly used statistical evaluation software packages provided different results regarding the stability of the candidate reference genes.

RESULTS

RefFinder revealed miRNA-106a and miRNA-21 as the most stably expressed reference genes, with comprehensive stability values of 1.189 and 1.861, respectively. U6-snRNA was the most unstable nucleic acid in our data. When 5 normalization strategies were compared using U6-snRNA, serum volume, miRNA-106a, miRNA-21, or the mean value of miRNA-106a and miRNA-21, obvious expression bias was detected in almost all target microRNAs. Intriguingly, all these normalization strategies indicated that circulating miRNA-155 is greatly upregulated in patients with HCC and GC, but downregulated in benign hepatic disease.

CONCLUSIONS

Single reference genes used without justification in plasma microRNAs produce significant analysis bias or even erroneous results. Circulating miRNA-155 may be a promising non-invasive biomarker for discriminating malignant digestive tumors from the corresponding benign diseases.

miR-615-3p expression level in bone marrow is associated with tumor recurrence in hepatocellular carcinoma

The significance of disseminated tumor cells (DTCs) in bone marrow (BM) on tumor recurrence has not been investigated in patients with hepatocellular carcinoma (HCC). The aim of te present study was to clarify the molecular characteristics of DTCs that affect postoperative recurrence based on microRNA (miRNA) expression profiles in clinical HCC patients undergoing curative resection. DTCs were prospectively collected from the BM of preoperative HCC patients using immunomagnetic beads and subjected to miRNA microarray analysis. Microarray analysis of nine HCC patients (n=5 patients with postoperative HCC recurrence, n=4 patients without HCC recurrence) demonstrated that miR-615-3p is significantly upregulated in the DTCs of patients with recurrence compared to the DTCs from patients without recurrence. In vitro experiments demonstrated that the miR-615-3p expression level is significantly correlated with malignant characteristics in HCC cells. These data suggest that miR-615-3p in DTCs may play an important role in postoperative HCC recurrence, which suggests that miR-615-3p is a potential target molecule for regulating postoperative HCC recurrence.

Update on biomarkers of hepatocellular carcinoma

New biomarkers of hepatocellular carcinoma (HCC) have been identified using advanced genomic, proteomic, and metabolomics technologies. These are being developed not only for use in diagnosis of HCC, but also in prediction of patient and treatment outcomes and individualization of therapy. Some HCC biomarkers are currently used in surveillance to detect early stage HCCs and reduce mortality. Further studies are needed to determine whether the recently identified HCC biomarkers can be used in clinical practice; most are only in phase 1 or 2 studies. The diagnostic and predictive abilities of biomarkers are limited by the heterogeneous nature of HCCs; there is no perfect single biomarker of this tumor. To improve performance, combinations of biomarkers (panels), or combinations of biomarkers and clinical parameters or laboratory test results, might be required. We describe recently discovered biomarkers of HCC and discuss challenges to their development and application.

Circulating microRNAs as noninvasive diagnostic biomarkers of liver disease in children with cystic fibrosis

OBJECTIVES

Cystic fibrosis liver disease (CFLD), resulting from progressive hepatobiliary fibrosis, causes significant morbidity and mortality in up to 20% of children with cystic fibrosis (CF). Both pathogenesis and early detection of CFLD are elusive. Current diagnostic procedures to detect early CFLD and stage fibrosis severity are inadequate. Recent studies highlight a role for microRNAs (miRNAs) in the pathogenesis of many diseases and have suggested that serum miRNAs could be used as diagnostic biomarkers.

METHODS

We profiled circulating serum miRNA levels in patients with CFLD (n = 52), patients with CF without liver disease (CFnoLD, n = 30), and non-CF pediatric controls (n = 20). Extracted RNA was subjected to polymerase chain reaction (PCR) array of 84 miRNAs detectable in human serum. Seven candidate miRNAs identified were validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), normalizing data to geNorm-determined stable reference genes, miR-19b and miR-93.

RESULTS

miR-122 was significantly elevated in patients with CFLD versus patients with CFnoLD and controls (P < 0.0001). miR-25 (P = 0.0011) and miR-21 (P = 0.0133) were elevated in patients with CFnoLD versus patients with CFLD and controls. CFLD was discriminated by both miR-122 (area under the curve [AUC] 0.71, P = 0.002) and miR-25 (AUC 0.65, P = 0.026). Logistic regression combining 3 miRNAs (-122, -25, -21) was greatly predictive of detecting CFLD (AUC 0.78, P < 0.0001). A combination of 6 miRNAs (-122, -21, -25, -210, -148a, -19a) distinguished F0 from F3-F4 fibrosis (AUC 0.73, P = 0.04), and miR-210 combined with miR-22 distinguished F0 fibrosis from any fibrosis, that is, F1-F4 (AUC 0.72, P = 0.02).

CONCLUSIONS

These data provide the first evidence of changes to circulating miRNA levels in CF, suggesting that serum-based miRNA analysis may complement and extend current CFLD screening strategies with potential to predict early hepatic fibrosis.

Diagnostic and therapeutic application of noncoding RNAs for hepatocellular carcinoma

MicroRNAs (miRNAs) are small, noncoding RNA molecules that regulate gene expression posttranscriptionally, targeting thousands of messenger RNAs. Long noncoding RNAs (lncRNAs), another class of noncoding RNAs, have been determined to be also involved in transcription regulation and translation of target genes. Since deregulated expression levels or functions of miRNAs and lncRNAs in hepatocellular carcinoma (HCC) are frequently observed, clinical use of noncoding RNAs for novel diagnostic and therapeutic applications in the management of HCCs is highly and emergently expected. Here, we summarize recent findings regarding deregulated miRNAs and lncRNAs for their potential clinical use as diagnostic and prognostic biomarkers of HCC. Specifically, we emphasize the deregulated expression levels of such noncoding RNAs in patients' sera as noninvasive biomarkers, a field that requires urgent improvement in the clinical surveillance of HCC. Since nucleotide-based strategies are being applied to clinical therapeutics, we further summarize clinical and preclinical trials using oligonucleotides involving the use of miRNAs and small interfering RNAs against HCC as novel therapeutics. Finally, we discuss current open questions, which must be clarified in the near future for realistic clinical applications of these new strategies.

Novel biomarkers for hepatocellular carcinoma surveillance: has the future arrived?

Hepatocellular carcinoma (HCC) remains a major cause of mortality in patients with chronic liver disease worldwide. Early detection of HCC is critical to providing effective treatment and can have a significant impact on survival. In addition, effective surveillance following hepatic resection or locoregional ablative therapy can identify early recurrence and optimize long-term outcomes. Currently available serum tumor markers, including alpha-fetoprotein (AFP), are characterized by low sensitivity in the detection of HCC. Advances in genomic, proteomic, metabolomic, and glycomic profiling may provide a means to identify unique molecular signatures and characterization of complex processes associated with HCC incidence and recurrence. The development of highly sensitive and specific serum biomarkers for HCC may greatly enhance early detection rates, risk assessment in treatment candidates, and identification of potential new targets for anticancer therapy.

Circulating miRNAs: roles in cancer diagnosis, prognosis and therapy

MicroRNAs (miRNAs) belong to a class of small non-coding RNAs that regulate numerous biological processes by targeting a broad set of messenger RNAs. Recently, miRNAs have been detected in remarkably stable forms in many types of body fluids. A comparison between cancer patients and healthy individuals has clearly shown that certain types of circulating miRNAs are associated with cancer initiation and progression. Research on miRNA-based biomarkers has witnessed phenomenal growth, owing to the non-invasive nature of miRNA-based screening assays and their sensitivity and specificity in detecting cancers. Consequently, a considerable effort has been devoted to identify suitable miRNAs for cancer diagnosis and also decode the information carried by circulating miRNAs. This review highlights the current studies that focus on the identification of circulating miRNA-based diagnostic and prognostic markers, for the most prevalent types of cancer. Additionally, the review also provides an insight into the putative functions of miRNAs, and attempts to delineate the mechanisms through which they are released into the bloodstream. Moreover, methodologies and strategies for identification of circulating miRNAs in cancers are summarized. Finally, potential strategies for circulating miRNA-based cancer therapies are proposed.

Circulating microRNA-21 as a biomarker for the detection of various carcinomas: an updated meta-analysis based on 36 studies

Cancer is a class of diseases with high mortality rate, characterized by unregulated cell growth. Early diagnosis of cancer is currently the most effective method to prevent cancer development and improve the survival rate of patients. Traditional diagnostic methods such as biopsy usually provoke discomfort and unpleasant experience. Recently, microRNAs (miRNAs) were widely reported to be potential biomarkers to detect cancers without invasiveness. MicroRNA-21 (miRNA-21, miR-21) is one of the most prevalent miRNAs. This meta-analysis aims to make a comprehensive analysis of the potential role of circulating miR-21 as a biomarker in human carcinoma diagnosis. A total of 36 articles involving 2920 cancer patients and 1986 healthy controls with regard to the diagnostic value of the circulating miR-21 for cancer detection were selected from online bibliographic databases. For pooled analysis, the sensitivity, specificity, and other basic characteristics were extracted from the 36 included articles. Then, bivariate random-effects model was selected to gain pooled results. Furthermore, to explore the sources of heterogeneity, we conducted stratified and meta-regression analyses based on different race/sample groups. The pooled characteristics of all included articles were as follows: sensitivity, 0.78 (95% confidence intervals (CI), 0.73-0.82); specificity, 0.82 (95% CI, 0.79-0.86); positive likelihood ratio (PLR), 4.4 (95% CI, 3.6-5.4); negative likelihood ratio (NLR), 0.26 (95% CI, 0.21-0.33); diagnostic odds ratio (DOR), 17 (95% CI, 12-24); and area under the curve (AUC), 0.87 (95% CI, 0.84-0.90). The subgroup analyses results based on different ethnic populations revealed that the diagnostic accuracy of miR-21 tends to be higher in Asian populations than in Caucasian populations. Furthermore, another subgroup analysis performed on sample types suggested that the serum-based specimen used in cancer diagnosis appeared to be more accurate than the plasma-based specimen. Our meta-analysis shows that the circulating miR-21 may be a potential biomarker as diagnostic tool for early-stage cancer diagnosis.

Emerging role of microRNA in hepatocellular carcinoma (Review)

Hepatocellular carcinoma is a type of cancer characterized by significant morbidity and high mortality rates worldwide. Previous studies have revealed that alterations in microRNA (miRNA) expression are a common feature of cancer. Furthermore, as evolutionarily conserved, non-encoding RNAs, miRNAs have demonstrated fundamental roles in the various biological processes involved in cancer. Genome-wide miRNA expression profile studies and bioinformatic methods have provided comprehensive insight into the role of cancer-related miRNAs. In addition, investigation of the function and mechanisms of miRNAs has provided an understanding of the association with the pathogenesis of cancer. In the present review, the tumor-promoting or tumor-suppressive roles and underlying mechanisms of certain significant miRNAs at a single and integral level are summarized. Furthermore, the recognition of miRNA-gene networks and current advances in the potential use of miRNA-based diagnosis and therapy are discussed.

Investigation of serum lncRNA-uc003wbd and lncRNA-AF085935 expression profile in patients with hepatocellular carcinoma and HBV

Hepatocellular carcinoma (HCC) was among the most common solid tumors which rated third in cancer-related mortality worldwide. Hepatitis B viral (HBV) infection represents an important risk factor for HCC. Long non-coding RNAs (lncRNAs) were a class of newfound non-coding RNAs widely depicted in the genome currently. Nevertheless, the potential roles of them in human cancers were not well comprehended. Through this study, we aimed at exploring the expression profile and the potential clinical value of two lncRNAs (lncRNA-uc003wbd and lncRNA-AF085935) in differentiating HCC from both HBV patients and the healthy specimens. Serum samples were extracted from 104 HBV patients, 137 HCC patients, and 138 healthy controls. The lncRNA levels of all the subjects were assayed by quantitative real-time reverse transcriptase-polymerase chain reaction (qRT-PCR). We differentiated the three groups by the receiver operating characteristic (ROC) curve of each group. Statistical analyses were conducted by GraphPad software. Two-tailed P value less than 0.05 was considered to be statistically significant. The level of serum lncRNA-uc003wbd and lncRNA-AF085935 was significantly upregulated in HCC patients and HBV patients compared with that in normal controls. LncRNA-AF085935 showed a relatively higher accuracy for HCC screening (area under the curve (AUC) = 0.96, 95 % confidence interval (CI) = 0.93-0.99) than lncRNA-uc003wbd (AUC = 0.86, 95 % CI = 0.82-0.91) from healthy controls, as well as for HCC screening (AUC = 0.86, 95 % CI = 0.80-0.91) which is more accurate than lncRNA-uc003wbd (AUC = 0.70, 95 % CI = 0.63-0.76) from HBV patients. When differentiating HBV patients from the normal group, the descriptive value of lncRNA-AF085935 (AUC = 0.77, 95 % CI = 0.71-0.83) was almost as equal to lncRNA-uc003wbd (AUC = 0.76, 95 % CI = 0.70-0.82). In addition, higher expressions of lncRNAs were observed in HCC patients than in HBV patients. LncRNA-uc003wbd and lncRNA-AF085935 were observed with an aberrant serum level in HCC and HBV patients, which is showing that both lncRNA-uc003wbd and lncRNA-AF085935 are able to be potential biomarkers for HCC and HBV screening.

The clinical utility of microRNA-21 as novel biomarker for diagnosing human cancers

With cancer being a major cause of death worldwide, microRNAs (miRNAs) have been investigated as novel and non-invasive biomarkers for cancer diagnosis. Recently, microRNA-21 (miR-21) attracts much attention for its aberrant expression and has been widely studied in various cancers. However, the inconsistent results from studies make it hard to evaluate the diagnostic value of miR-21 in cancer diagnosis, which lead us to conduct this meta-analysis. We conducted a comprehensive literature search in the Medline, Embase, PubMed, CNKI, and Web of Science before July 1, 2014. STATA 12.0 software was used for calculation and statistical analysis. The pooled sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR), and diagnostic odds ratio (DOR) were used to assess the diagnostic performance of miR-21 for cancers. Seventy-three studies in 60 articles were involved in this meta-analysis, with a total of 4684 patients with cancer and 3108 controls. The overall parameters were calculated from all the included studies: sensitivity of 0.78 (95% confidence interval (CI) 0.74-0.81), specificity of 0.83 (95% CI 0.80-0.86), PLR of 4.5 (95% CI 3.8-5.4), NLR of 0.27 (95% CI 0.23-0.32); DOR of 17 (95% CI 12-23), and area under the curve (AUC) of 0.88 (95% CI 0.84-0.90). In addition, we performed subgroup analyses based on ethnicity, cancer types, and sample types. Results from subgroup analysis showed that cancer types and sample types were the sources of heterogeneity in our meta-analysis. The overall diagnostic value of miR-21 is not very high for cancer diagnosis; however, it is affected significantly by the types of cancer and specimen. MiR-21 has a relatively high diagnostic value for detecting breast cancer, and miR-21 assays based on plasma, serum, and tissue achieved relatively higher accuracy.

Hepatocellular carcinoma tumour markers: current role and expectations

Tumour markers could be helpful along the continuum of care for patients with hepatocellular carcinoma; however, there is insufficient data for routine use of most current biomarkers in clinical practice. Therefore, the backbone of early detection, diagnosis and treatment response for hepatocellular carcinoma remains imaging-based. Alpha fetoprotein is the best studied of all biomarkers and may be of benefit for early detection when used in combination with ultrasound. Several other biomarkers, including AFP-L3, DCP, osteopontin, and GP73, are also being evaluated for early detection of hepatocellular carcinoma in phase III biomarker studies. Serum and tissue-based biomarkers and genomics may aid in HCC diagnosis, prognosis, and treatment selection; however, further studies are needed to better characterize their accuracy and potential role in clinical practice.

Circulating RNA molecules as biomarkers in liver disease

Liver disease is a major cause of morbidity and mortality worldwide. As in other fields of medicine, there is a stringent need for non-invasive markers to improve patient diagnostics, monitoring and prognostic ability in liver pathology. Cell-free circulating RNA molecules have been recently acknowledged as an important source of potential medical biomarkers. However, many aspects related to the biology of these molecules remain to be elucidated. In this review, we summarize current concepts related to the origin, transportation and possible functions of cell-free RNA. We outline current development of extracellular RNA-based biomarkers in the main forms of non-inherited liver disease: chronic viral hepatitis, hepatocellular carcinoma, non-alcoholic fatty liver, hepato-toxicity, and liver transplantation. Despite recent technological advances, the lack of standardization in the assessment of these markers makes their adoption into clinical practice difficult. We thus finally review the main factors influencing quantification of circulating RNA. These factors should be considered in the reporting and interpretation of current findings, as well as in the proper planning of future studies, to improve reliability and reproducibility of results.

A serum microRNA panel as potential biomarkers for hepatocellular carcinoma related with hepatitis B virus

BACKGROUND

The identification of new high-sensitivity and high-specificity markers for HCC are essential. We aimed to identify serum microRNAs (miRNAs) as biomarkers to be used in diagnosing hepatitis B virus (HBV) -related hepatocellular carcinoma (HCC).

METHODS

We investigated serum miRNA expression in (261 HCC patients, 233 cirrhosis patients, and 173 healthy controls), recruited between August 2010 and June 2013. An initial screening of miRNA expression by Illumina sequencing was performed using serum samples pooled from HCC patients and controls. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was used to evaluate the expression of selected miRNAs. A logistic regression model was constructed using a training cohort (n = 357) and then validated using an independent cohort (n = 241). The area under the receiver operating characteristic curve (AUC) was used to evaluate the accuracy of the use of the biomarkers for disease diagnosis.

RESULTS

We identified 8 miRNAs (hsa-miR-206, hsa-miR-141-3p, hsa-miR-433-3p, hsa-miR-1228-5p, hsa-miR-199a-5p, hsa-miR-122-5p, hsa-miR-192-5p, and hsa-miR-26a-5p) and constructed an miRNA set that provided high diagnostic accuracy for HCC (AUC = 0.887 and 0.879 for training and validation sets, respectively). The miRNAs could also be used to differentiate HCC patients from healthy (AUC = 0.893) and cirrhosis (AUC = 0.892) patients.

CONCLUSIONS

We identified a serum of miRNA panel that has considerable clinical value in HCC diagnosis.

MicroRNAs associated with HBV infection and HBV-related HCC

Hepatitis B virus (HBV) infection is a global problem and a major risk factor for hepatocellular carcinoma (HCC). microRNAs (miRNAs) comprise a group of small noncoding RNAs regulating gene expression at the posttranslational level, thereby participating in fundamental biological processes, including cell proliferation, differentiation, and apoptosis. In this review, we summarize the roles of miRNAs in HBV infection, the recently identified mechanism underlying dysregulation of miRNAs in HBV-associated HCC, and their association with hepatocarcinogenesis. Moreover, we discuss the recent advances in the use of circulating miRNAs in the early diagnosis of HCC as well as therapies based on these aberrantly expressed miRNAs.

Circulating microRNA 483-5p as a novel biomarker for diagnosis survival prediction in multiple myeloma

Dysregulation of miRNA expression plays an important role in cancer development, and circulating miRNAs are biomarkers of several cancers. We explored whether the miRNAs in plasma could be useful clinical biomarkers for multiple myeloma. miRNA microarray was conducted to identify elevation of four miRNAs and reduced levels of eight miRNAs in the plasma of nine multiple myeloma patients and seven healthy controls. Increased miR-483-5p levels and decreased miR-20a were further validated in the plasma of 40 myeloma patients and 20 healthy controls using TaqMan quantitative real-time PCR. Receiver operating characteristic (ROC) analysis revealed that miR-483-5p and miR-20a had considerable diagnostic accuracy, yielding the areas under the ROC curve of 0.745 (sensitivity 58%, specificity 90%) and 0.74 (sensitivity 63%, specificity 85%), respectively. Plasma levels of miR-483-5p were associated with ISS staging. Within 14 months of diagnosis, the median progression-free survival of patients with high levels of plasma miR-483-5p was 15 months, in comparison with 21 months for patients with low levels of plasma miR-483-5p (p=0.025). However, miR-20a levels were not correlated with progression-free survival (p>0.05). miR-483-5p has the potential to be a predictor of myeloma survival.

MicroRNAs as a novel class of diagnostic biomarkers in detection of hepatocellular carcinoma: a meta-analysis

MicroRNAs (miRNAs) have been proposed as promising diagnostic biomarkers for many diseases, particularly in the field of cancer research. Numerous studies have explored the use of miRNAs in the detection of hepatocellular carcinoma (HCC), with some reporting inconsistent results. Thus, we conducted this meta-analysis to evaluate the potential diagnostic value of miRNAs in HCC. All relevant literature was collected from the PubMed and other databases before June 3, 2014. The summary receiver operator characteristic (SROC) curve and other parameters were used to estimate overall predictive performance. Fourteen studies involving 1,848 cases with HCC and 1,187 controls (576 healthy controls and 611 individuals with chronic liver diseases) were included in this meta-analysis. SROC analyses for the diagnostic power of miRNAs yielded an area under the curve (AUC) of 0.93 with 86 % sensitivity and 86 % specificity in discriminating patients with HCC from healthy subjects and an AUC of 0.88 with 79 % sensitivity and 83 % specificity in differentiating patients with HCC from those with chronic liver diseases (CLDs). Furthermore, subgroup analyses showed that miRNA panels yielded excellent diagnostic characteristics, with an AUC of 0.99 (96 % sensitivity and 96 % specificity) for detection of HCC from healthy controls and an AUC of 0.93 (85 % sensitivity and 88 % specificity) for HCC from those with CLDs. MiRNAs might be novel potential biomarkers for the diagnosis of HCC, and a combination of multiple miRNAs could significantly improve the diagnostic accuracy.

miRNAs: new tools for molecular classification, diagnosis and prognosis of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) remains one of the most common malignancies worldwide, ranking as the third leading cause of cancer-related death. With recent advances in understanding HCC biology, progress has been made in early detection and management of HCC; however, its prognosis remains dismal. Novel biomarkers for HCC that are acceptable for clinical utility are urgently in need. Recently, miRNA has emerged as an important class of gene regulator that controls various cellular processes including cancer development. In HCC, miRNAs are frequently dysregulated, and studies have shown great promises of miRNAs as biomarkers for tumor classification, diagnosis and prognosis. Given miRNAs are highly stable in blood plasma and serum, they are suggested as a new class of noninvasive biomarker for detection of HCC. In this article, we provide an up-to-date review of the recent findings of the use of miRNAs in molecular classification of HCC tumors, diagnosis and prognosis.

Regulation of viral oncogenesis by microRNAs

Viral infection may play a causative role in human cancers, for example hepatitis B virus (HBV) or hepatitis C virus (HCV) in liver cancer, human papilloma virus (HPV) in cervical cancer, and Epstein-Barr virus (EBV) in nasopharyngeal carcinoma. Virally infected cells express viral-encoded genes that are critical for oncogenesis. Some viruses also encode microRNA (miRNA) species. miRNAs are small noncoding RNA molecules that play an important role in cancer development and progression. Recent studies indicate an important interplay among viral oncoproteins, virus-encoded miRNAs, cellular miRNAs, and cellular genes. This review focuses on modulation of HBV-, HCV-, HPV-, and EBV-associated cancers by cellular and/or viral miRNA. An understanding of the mechanisms underlying the regulation of viral carcinogenesis by miRNAs may provide new targets for the development of specific viral therapies.

Expression profiling of serum microRNA-101 in HBV-associated chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma

MicroRNAs (miRNAs) represent a class of evolutionarily conserved, non-coding small RNAs (18-25 nt) that have emerged as master regulators of several biological processes. Recently, circulating miRNAs have also been reported to be promising biomarkers for various pathological conditions. In the present study, we report the comparative expression profiling of microRNA-101 (miR-101) in serum and tissue samples from chronic hepatitis B (CHB), HBV-associated liver cirrhosis (HBV-LC), and HBV-associated hepatocellular carcinoma (HBV-HCC) patients and healthy controls. The serum miR-101 levels were found to be significantly downregulated in the HBV-HCC patients compared with the HBV-LC patients (P<0.001), CHB patients (P<0.001) and healthy controls but were upregulated in the HBV-LC patients compared with the CHB patients (P<0.001) and healthy controls (P<0.001). Consistent with the serum data, the expression of miR-101 was also upregulated and downregulated in the HBV-LC and HBV-HCC tissue samples, respectively. A receiver operating characteristic (ROC) analysis of serum miR-101 yielded an area under the ROC curve (AUC) of 0.976 with 95.5% sensitivity and 90.2% specificity when differentiating between HBV-HCC and HBV-LC. Our results suggest that the serum miR-101 level can serve as a potential non-invasive biomarker to differentiate HBV-HCC from HBV-LC.

Model based on γ-glutamyltransferase and alkaline phosphatase for hepatocellular carcinoma prognosis

AIM: To determine the prognostic value of alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) for hepatocellular carcinoma (HCC) .

METHODS: We analyzed the outcome of 172 HCC patients who underwent liver resection. Receiver operating characteristic (ROC) curve analysis was performed to determine the cut-off value of ALP and GGT. Then, preoperative risk factors for survival were evaluated by multivariate analysis. Based on the significant factors, a prognostic score model was established.

RESULTS: By ROC curve analysis, ALP > 120 U/L and GGT > 115 U/L were considered elevated. Overall survival (OS) and tumor-free survival (TFS) for patients with elevated ALP and GGT were significantly worse than for patients with ALP and GGT within the normal range. Multivariate analysis showed that the elevated levels of ALP, GGT and tumor size were independent prognostic factors. Giving each positive factor as a score of 1, we established a preoperative prognostic score model. The 5-year OS for patients with a score of 0, 1, 2 and 3 were 84.0%, 45.9%, 44.1% and 0%, respectively, while the TFS was 80.6%, 40.0%, 38.8% and 0%, respectively. When combining patients with scores of 1 and 2 into the middle risk group, and patients with scores of 0 and 3 into the low-risk and high-risk groups, respectively, different outcomes would be significantly distinguished by the risk groups.

CONCLUSION: Elevated ALP and GGT levels were risk predictors in HCC patients. Our prognostic model might vary the outcomes of patients from different risk groups.

Implications of biomarkers in human hepatocellular carcinoma pathogenesis and therapy

Hepatocellular carcinoma (HCC) is one of the most frequent tumors worldwide and accounts for approximately one-third of all malignancies. In the past decade, advances have been made to improve the prognosis of HCC, including improvement in the clinical diagnosis of early-stage HCC using molecular biomarkers and molecular-targeted therapy to treat advanced HCC. However, the diagnosis, pathogenesis and targeted therapy of HCC are not completely independent, and should be comprehensively studied. For example, a number of tumor markers provide useful clinical information not only for prognosis, but also in pathogenesis and treatment efficacy. Therefore, this review will focus on the role of several specific biomarkers implicated in the pathogenesis of HCC and several promising molecular-targeted drugs that target the biomarkers of 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.

Diagnostic value of circulating microRNAs for hepatocellular carcinoma

Much evidence indicates that microRNAs could play potential roles as diagnostic and prognostic biomarkers of human cancers, including hepatocellular carcinoma (HCC). The present meta-analysis aimed to systematically evaluate the diagnostic accuracy of circulating microRNAs for HCC. Eligible studies were identified through multiple search strategies and assessed for relevance and quality. Results from different studies were pooled using random-effects models. The quality of each study was scored with the revised quality assessment of diagnostic accuracy studies tool. The summary receiver operator characteristic (SROC) curve and other measures were used to assess the overall performance of microRNA-based assays. Evidence of heterogeneity was evaluated using the I (2) test. Meta-regressions were conducted to analyze potential sources of heterogeneity. Deeks' test was used to test for potential publication bias. Thirty studies from 13 publications, including 1,314 patients with HCC and 1,407 controls, comprised healthy individuals and patients with hepatitis B/C or cirrhosis, were included in this meta-analysis. For diagnostic meta-analysis, the overall pooled results were as follows: sensitivity was 0.80 (95 % CI 0.74-0.84), specificity was 0.81 (95 % CI 0.74-0.87), positive likelihood ratio was 4.2 (95 % CI 3.0-6.0), negative likelihood ratio was 0.25 (95 % CI 0.19-0.38) and diagnostic odds ratio was 17 (95 % CI 10-29). The area under the SROC curve was 0.86 (95 % CI 0.84-0.90). Subgroup analyses suggested that multiple microRNAs had much better accuracy than single microRNA. Our findings suggest that circulating microRNAs show significant potential as diagnostic markers of HCC, particularly when using multiple microRNAs. However the results of this meta-analysis justify larger, more rigorous studies to confirm our conclusions.

MicroRNA-451 regulates activating transcription factor 2 expression and inhibits liver cancer cell migration

Accumulating evidence suggests that microRNAs (miRNAs) can function as oncogenes or as tumor suppressor genes depending on the tissue type or target. Therefore, clarification of the specific roles of miRNAs is vital for the diagnosis and treatment of cancer. In the present study, miR-451 was found to be downregulated in hepatocellular carcinoma (HCC) tissues when compared to that in adjacent tissues. Functional analysis showed that, in vitro, miR-451 inhibited the migration of hepatoma cell lines HepG2 and SK-Hep-1. Further investigation of the molecular mechanisms identified activating transcription factor 2 (ATF2) as a target of miR-451. miR-451 inhibited ATF2 expression by binding to the 3'UTR. An in vivo assay revealed a significant negative correlation between miR-451 and ATF2 in liver cancer tissues. According to previous findings reported in the literature, the opposing functions of ATF2 are related to its subcellular localization. In the nucleus, ATF2 displays oncogenic activities in melanoma. In the present study, ATF2 exhibited a higher expression level in the nucleus in tumoral tissues of HCC as detected by immunohistochemistry. In conclusion, in this study, we identified a potential target of miR-451, ATF2, and revealed a novel role of miR-451 in the inhibition of the migratory ability of hepatoma cell lines.

MicroRNA and hepatitis C virus--challenges in investigation and translation: a review of the literature

Investigations into the role of microRNA (miRNA) in hepatitis C virus (HCV) infection, disease pathogenesis and host immune and treatment response have potential to produce innovations in diagnosis, prognosis and therapy. However, investigational challenges remain in generating clinically useful and reproducible results. We review the literature with a primary emphasis on methods and technologies used to construct our current understanding of miRNA and HCV disease. A second emphasis is to understand potential clinical research applications and provide clarification of previous study results. Many miRNA have key roles in viral and immunopathogenesis of HCV infection across multiple tissue compartments. Controversy exists among published studies regarding relative measurements, temporal changes and biological significance of specific miRNA and HCV infection. To reconcile diverging data, additional research into optimal sample processing, in vitro models, techniques for microarray differential expression of miRNAs, practices for sample result normalization, and effect of HCV genotype variation on expression are all necessary. Microarray and miRNA isolation techniques should be selected based on ability to generate reproducible results in the sample type of interest. More direct comparisons of efficacy and reliability of various multiplex microarrays and an improved consensus around miRNA normalization and quantitation are necessary so that data can be compared across studies.

Expression of serum exosomal microRNA-21 in human hepatocellular carcinoma

New strategies for the diagnosis of hepatocellular carcinoma (HCC) are urgently needed. There is an increasing interest in using microRNAs (miRNAs) as biomarkers in diseases. In this study, we examined the expression of miR-21 in serum exosomes from patients with HCC or chronic hepatitis B (CHB) and investigated the potential clinical significance of miR-21. Quantitative RT-PCR indicated that the concentration of miR-21 was significantly higher in exosomes than in exosome-depleted supernatants or the whole serum. Further, the expression level of serum exosomal miR-21 was significantly higher in patients with HCC than those with CHB or healthy volunteers (P < 0.0001, P < 0.0001, resp.). High level of miR-21 expression correlated with cirrhosis (P = 0.024) and advanced tumor stage (P = 0.001). Although serum level of miR-21 was higher in patients with HCC than in patients with CHB and healthy volunteers, the sensitivity of detection is much lower than using exosomal miR-21. These findings indicate that miR-21 is enriched in serum exosomes which provides increased sensitivity of detection than whole serum. Exosomal miR-21 may serve as a potential biomarker for HCC diagnosis.

MicroRNA in gastrointestinal cancer: a step closer to reality

Despite significant strides in understanding molecular pathogenesis of cancer, gastrointestinal malignancy (gastric, colorectal, pancreatic, and liver) still ranks among the leading causes of cancer-related mortality and morbidity worldwide. One of the key clinical challenges in effectively reducing disease burden associated with gastrointestinal neoplasia stems from late diagnosis, underscoring the need for early detection, risk assessment, and intervention. Currently available screening approaches are inadequate, and the development of accurate noninvasive molecular biomarkers is very much needed, microRNAs (miRNAs) are short (20-24 nucleotides in length) noncoding RNAs that have emerged as important translational gene regulators in cancer cells. In contrast to genetic markers, miRNAs have a cancer-specific expression pattern. They are present in a remarkably stable form and can be detected in a wide variety of body fluids including blood and feces. These properties make them attractive cancer biomarker targets. Although development of miRNA biomarkers is still in its early stages, burgeoning evidence supports their potential use for development as markers for early detection, prognosis, and prediction of disease recurrence and therapeutic outcome in gastrointestinal cancers. In the future, it is likely that miRNA biomarkers will revolutionize personalized medicine and mitigate disease burden associated with gastrointestinal cancers.

A knowledge base for the discovery of function, diagnostic potential and drug effects on cellular and extracellular miRNAs

Background

MicroRNAs (miRNAs) are small noncoding RNAs that play an important role in the regulation of various biological processes through their interaction with cellular mRNAs. A significant amount of miRNAs has been found in extracellular human body fluids (e.g. plasma and serum) and some circulating miRNAs in the blood have been successfully revealed as biomarkers for diseases including cardiovascular diseases and cancer. Released miRNAs do not necessarily reflect the abundance of miRNAs in the cell of origin. It is claimed that release of miRNAs from cells into blood and ductal fluids is selective and that the selection of released miRNAs may correlate with malignancy. Moreover, miRNAs play a significant role in pharmacogenomics by down-regulating genes that are important for drug function. In particular, the use of drugs should be taken into consideration while analyzing plasma miRNA levels as drug treatment. This may impair their employment as biomarkers.

Description

We enriched our manually curated extracellular/circulating microRNAs database, miRandola, by providing (i) a systematic comparison of expression profiles of cellular and extracellular miRNAs, (ii) a miRNA targets enrichment analysis procedure, (iii) information on drugs and their effect on miRNA expression, obtained by applying a natural language processing algorithm to abstracts obtained from PubMed.

Conclusions

This allows users to improve the knowledge about the function, diagnostic potential, and the drug effects on cellular and circulating miRNAs.

Regulation of microRNAs and their role in liver development, regeneration and disease

Since their discovery more than a decade ago microRNAs have been demonstrated to have profound effects on almost every aspect of biology. Numerous studies in recent years have shown that microRNAs have important roles in development and in the etiology and progression of disease. This review is focused on microRNAs and the roles they play in liver development, regeneration and liver disease; particularly chronic liver diseases such as alcoholic liver disease, non-alcoholic fatty liver disease, non-alcoholic steatohepatitis, viral hepatitis and primary liver cancer. The key microRNAs identified in liver development and chronic liver disease will be discussed together with, where possible, the target messenger RNAs that these microRNAs regulate to profoundly alter these processes. This article is part of a Directed Issue entitled: The Non-coding RNA Revolution.

MicroRNAs in hepatocellular carcinoma: carcinogenesis, progression, and therapeutic target

Hepatocellular carcinoma (HCC) is the third leading cause of death from cancer, with dismal outcomes and an increasing incidence worldwide. Hepatocarcinogenesis is a multistep process that progresses from chronic hepatitis through cirrhosis and/or dysplastic nodule to HCC. However, the detailed molecular pathogenesis remains unclear. MicroRNAs (miRNAs), small noncoding RNAs that regulate the translation of many genes, have emerged as key factors involved in several biological processes, including development, differentiation, and cell proliferation. Recent studies have uncovered the contribution of miRNAs to the cancer pathogenesis, as they can behave as oncogenes or tumor suppressor genes. In addition, other studies have demonstrated their potential values in the clinical management of HCC patients as some miRNAs may be used as prognostic or diagnostic markers. In this review, we summarize current knowledge about the roles of miRNAs in carcinogenesis and progression of HCC. We also discuss the potential application of miRNAs as diagnostic biomarkers and their potential roles in the intervention of HCC.

Clinical relevance of plasma miR-21 in new-onset systemic lupus erythematosus patients

BACKGROUND

Plasma miR-21 is widely investigated as biomarker in many diseases. Recent studies show that miR-21 participates in the development of systemic lupus erythematosus (SLE). The aim of this study was to evaluate the expression profile of miR-21 in the plasma of SLE patients.

METHODS

Relative quantities of plasma miR-21 both in SLE patients and healthy controls were determined by relative qRT-PCR under endogenous and exogenous controls. The diagnostic value of plasma miR-21 was evaluated in SLE patients. Data of some SLE-associated clinical parameters were collected.

RESULTS

Eighty participants from Central China were recruited. Forty-four participants were new-onset SLE patients and the others were healthy controls. Plasma miR-21 level in SLE patients was higher than that of healthy controls (P = 0.031). Receiver operating characteristic analysis of plasma miR-21 revealed an Area Under Curve (AUC) of 0.64 ± 0.06 (95% CI: 0.51-0.76, P = 0.03854) when differentiating SLE from healthy controls. The level of plasma miR-21 was not associated with the level of white blood cells (P = 0.4284), red blood cells (P = 0.4079), and platelets (P = 0.4961), but significantly correlated with the level of plasma complement C3 (r = -0.5297, P = 0.0004), C4 (r = -0.4732, P = 0.0020), and serum uric acid (r = 0.3932, P = 0.0121) in SLE patients.

CONCLUSIONS

Plasma miR-21 in SLE patients from Central China is overexpressed. Since circulating miR-21 is aberrantly expressed in many diseases, the applying of it as a disease biomarker should be considered carefully.

The microRNAs as potential biomarkers for predicting the onset of aflatoxin exposure in human beings: a review

The identification of aflatoxins as human carcinogens has stimulated extensive research efforts, which continue to the present, to assess potential health hazards resulting from contamination of the human food supply and to minimize exposure. The use of biomarkers that are mechanistically supported by toxicological studies will be important tools for identifying stages in the progression of development of the health effects of environmental agents. miRNAs are small non-coding mRNAs that regulate post-transcriptional gene expression. Also, they are molecular markers of cellular responses to various chemical agents. Growing evidence has demonstrated that environmental chemicals can induce changes in miRNA expression. miRNAs are good biomarkers because they are well defined, chemically uniform, restricted to a manageable number of species, and stable in cells and in the circulation. miRNAs have been used as serological markers of HCC and other tumors. The expression patterns of different miRNAs can distinguish among HCC-hepatitis viruses related, HCC cirrhosis-derivate, and HCC unrelated to either of them. The main objective of this review is to find unreported miRNAs in HCC related to other causes, so that they can be used as specific molecular biomarkers in populations exposed to aflatoxins and as early markers of exposure, damage/presence of HCC. Until today specific miRNAs as markers for aflatoxins-exposure and their reliability are currently lacking. Based on their elucidated mechanisms of action, potential miRNAs that could serve as possible markers of HCC by exposure to aflatoxins are miR-27a, miR-27b, miR-122, miR-148, miR-155, miR-192, miR-214, miR-221, miR-429, and miR-500. Future validation for all of these miRNAs will be needed to assess their prognostic significance and confirm their relationship with the induction of HCC due to aflatoxin exposure.

Epigenetic regulation of connective tissue growth factor by MicroRNA-214 delivery in exosomes from mouse or human hepatic stellate cells

Connective tissue growth factor (CCN2) drives fibrogenesis in hepatic stellate cells (HSC). Here we show that CCN2 up-regulation in fibrotic or steatotic livers, or in culture-activated or ethanol-treated primary mouse HSC, is associated with a reciprocal down-regulation of microRNA-214 (miR-214). By using protector or reporter assays to investigate the 3'-untranslated region (UTR) of CCN2 mRNA, we found that induction of CCN2 expression in HSC by fibrosis-inducing stimuli was due to reduced expression of miR-214, which otherwise inhibited CCN2 expression by directly binding to the CCN2 3'-UTR. Additionally, miR-214 was present in HSC exosomes, which were bi-membrane vesicles, 50-150 nm in diameter, negatively charged (-26 mV), and positive for CD9. MiR-214 levels in exosomes but not in cell lysates were reduced by pretreatment of the cells with the exosome inhibitor, GW4869. Coculture of either quiescent HSC or miR-214-transfected activated HSC with CCN2 3'-UTR luciferase reporter-transfected recipient HSC resulted in miR-214- and exosome-dependent regulation of a wild-type CCN2 3'-UTR reporter but not of a mutant CCN2 3'-UTR reporter lacking the miR-214 binding site. Exosomes from HSC were a conduit for uptake of miR-214 by primary mouse hepatocytes. Down-regulation of CCN2 expression by miR-214 also occurred in human LX-2 HSC, consistent with a conserved miR-214 binding site in the human CCN2 3'-UTR. MiR-214 in LX-2 cells was shuttled by way of exosomes to recipient LX-2 cells or human HepG2 hepatocytes, resulting in suppression of CCN2 3'-UTR activity or expression of CCN2 downstream targets, including alpha smooth muscle actin or collagen. Experimental fibrosis in mice was associated with reduced circulating miR-214 levels.

CONCLUSION

Exosomal transfer of miR-214 is a paradigm for the regulation of CCN2-dependent fibrogenesis and identifies fibrotic pathways as targets of intercellular regulation by exosomal miRs.