performed the experiments and along with Grant A. Ramm analyzed the data. Diego A. Calvopina and Gunter F. Hartel performed the more advanced statistical analyses. Louise E. Ramm collected clinical data and maintained the patient database. Peter J. Lewindon assisted in study design, enrollment of patients and collection of liver tissue specimens. Charlton Noble also helped enroll patients in the study and collected tissue specimens. Daniel H. Leung provided advice on study design.

Early diagnosis of cirrhosis and hepatocellular carcinoma (HCC) due to chronic Hepatitis C (CHC) remain clinical priorities. In this pilot study, we assessed serum microRNA (miRNA) expression to distinguish cirrhosis and HCC, alone and in combination with the aminotransferase-to-platelet ratio (APRI), Fibrosis 4 (FIB-4), and alpha-fetoprotein (AFP). Sixty CHC patients were subdivided into 3 cohorts: Mild disease (fibrosis stage F0-2; n = 20); cirrhosis (n = 20); and cirrhosis with HCC (n = 20). Circulating miRNA signatures were determined using a liver-specific real-time quantitative reverse transcription PCR (qRT-PCR) microarray assessing 372 miRNAs simultaneously. Differentially-expressed miRNA candidates were independently validated using qRT-PCR. Serum miRNA-409-3p was increased in cirrhosis versus mild disease. In HCC versus cirrhosis, miRNA-486-5p was increased, whereas miRNA-122-5p and miRNA-151a-5p were decreased. A logistic regression model-generated panel, consisting of miRNA-122-5p + miRNA-409-3p, distinguished cirrhosis from mild disease (area under the curve, AUC = 0.80; sensitivity = 85%, specificity = 70%; p < 0.001). When combined with FIB-4 or APRI, performance was improved with AUC = 0.89 (p < 0.001) and 0.87 (p < 0.001), respectively. A panel consisting of miRNA-122-5p + miRNA-486-5p + miRNA-142-3p distinguished HCC from cirrhosis (AUC = 0.94; sensitivity = 80%, specificity = 95%; p < 0.001), outperforming AFP (AUC = 0.64, p = 0.065). Serum miRNAs are differentially expressed across the spectrum of disease severity in CHC. MicroRNAs have great potential as diagnostic biomarkers in CHC, particularly in HCC where they outperform the only currently-used biomarker, AFP.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer in the world with 600,000 new cases diagnosed annually. Tobacco and alcohol use have been associated as the principal etiological factors of this pathogenesis. The incidence of smoking-associated HNSCC has declined, while human papilloma virus (HPV)-associated HNSCC is on the rise. There are currently no clinically validated biomarkers to detect this cancer at an early stage (cancers independent of HPV status). It is well-established that the aberrant expression of miRNAs can lead to tumorigenesis. miRNA expression differences have also been demonstrated in HPV-positive and HPV-negative HNSCC tumor tissues as well as in body fluids. Therefore, miRNAs have the potential to provide an unprecedented insight into the pathogenesis of HNSCC and serve as potential biomarkers. This review addresses HNSCC disease burden and the regulation of miRNA by HPV viral oncoproteins, potential miRNA biomarkers and future perspectives. miRNA provides an unique opportunity to fulfill the current clinical challenge in HNSCC patient management by enabling early detection followed by targeted interventions, leading to a significant reduction in mortality and morbidity.

Head and neck squamous cell carcinomas (HNSCC) are a heterogeneous group of tumours that originate predominantly from the oral cavity, pharynx and larynx. Our aim was to determine whether salivary miRNA expression levels can diagnose these cancer subtypes. Saliva samples were collected from healthy controls (n=113, smoker and non-smokers), HPV-positive (n=54) and HPV-negative (n=47) HNSCC patients. The miRNA expression levels in saliva was quantified using qPCR. The potential of salivary miRNAs to discriminate these groups of patients was evaluated using multiple logistic regression with ROC analysis and a 10-fold cross-validation analysis. Salivary miRNA-9, -127, -134, -191, -222 and -455 were shown to discriminate a control group from a HPV-negative HNSCC patient group with a sensitivity of 60% and a specificity of 94%; whilst salivary miRNA-9,-134, -196b, -210, and -455 were the most parsimonious subset discriminating a control group from a HPV-positive HNSCC group, with a sensitivity of 65% and a specificity of 95%. Furthermore, miRNA-9, -134, -196b, -210 and -455 as a panel, was the most parsimonious subset to discriminate HPV-positive HNSCC patients from HPV-negative HNSCC patients. In addition, the expression levels of miRNA-9, -127, -196a, -196b, -210, -222 and -455 were significantly increased in the saliva collected from early stage HNSCC patients compared to controls. A future multi-centre confirmatory study is warranted to test the diagnostic performance of these salivary miRNA prior to clinical implementation.

No abstract

MicroRNAs (miRNAs) are short non-coding RNAs involved in biological and pathological processes of every cell type, including liver cells. Transcribed from specific genes, miRNA precursors are processed in the cytoplasm into mature miRNAs and as part of the RNA-induced silencing complex (RISC) complex binds to messenger RNA (mRNA) by imperfect complementarity. This leads to the regulation of gene expression at a post-transcriptional level. The function of a number of different miRNAs in fibrogenesis associated with the progression of chronic liver disease has recently been elucidated. Furthermore, miRNAs have been shown to be both disease-and tissue-specific and are stable in the circulation, which has led to increasing investigation on their utility as biomarkers for the diagnosis of chronic liver diseases, including those in children. Here, we review the current knowledge on the biogenesis of microRNA, the mechanisms of translational repression and the use of miRNA as circulatory biomarkers in chronic paediatric liver diseases including cystic fibrosis associated liver disease, biliary atresia and viral hepatitis B.

Cystic fibrosis (CF)-associated liver disease (CFLD) is a hepatobiliary complication of CF. Current diagnostic modalities rely on nonspecific assessments, whereas liver biopsy is the gold standard to assess severity of fibrosis. MicroRNAs (miRNAs) regulate liver disease pathogenesis and are proposed as diagnostic biomarkers. We investigated the combined use of serum miRNAs and aspartate aminotransferase (AST) to platelet ratio (APRI) to diagnose and assess CFLD severity. This was a cross-sectional cohort study of the circulatory miRNA signature of 124 children grouped by clinical, biochemical, and imaging assessments as follows: CFLD (n = 44), CF patients with no evidence of liver disease (CFnoLD; n = 40), and healthy controls (n = 40). Serum miRNAs were analyzed using miRNA sequencing (miRNA-Seq). Selected differentially expressed serum miRNA candidates were further validated by qRT-PCR and statistical analysis performed to evaluate utility to predict CFLD and fibrosis severity validated by liver biopsy, alone or in combination with APRI. Serum miR-122-5p, miR-365a-3p, and miR-34a-5p levels were elevated in CFLD compared to CFnoLD, whereas miR-142-3p and let-7g-5p were down-regulated in CFLD compared to CFnoLD. Logistic regression analysis combining miR-365a-3p, miR-142-3p, and let-7g-5p with APRI showed 21 times greater odds of accurately predicting liver disease in CF with an area under the receiver operating characteristics curve (AUROC) = 0.91 (sensitivity = 83%, specificity = 92%; P < 0.0001). Expression levels of serum miR-18a-5p were correlated with increasing hepatic fibrosis (HF) stage in CFLD (r = 0.56; P < 0.0001), showing good diagnostic accuracy for distinguishing severe (F3-F4) from mild/moderate fibrosis (F0-F2). A unit increase of miR-18a-5p showed a 7-fold increased odds of having severe fibrosis with an AUROC = 0.82 (sensitivity = 93%, specificity = 73%; P = 0.004), indicating its potential to predict fibrosis severity. Conclusion: We identified a distinct circulatory miRNA profile in pediatric CFLD with potential to accurately discriminate liver disease and fibrosis severity in children with CF.

During chronic liver injury hepatic stellate cells (HSCs), the principal source of extracellular matrix in the fibrotic liver, transdifferentiate into pro-fibrotic myofibroblast-like cells - a process potentially regulated by microRNAs (miRNAs). Recently, we found serum miRNA-25-3p (miR-25) levels were upregulated in children with Cystic Fibrosis (CF) without liver disease, compared to children with CF-associated liver disease and healthy individuals. Here we examine the role of miR-25 in HSC biology. MiR-25 was detected in the human HSC cell line LX-2 and in primary murine HSCs, and increased with culture-induced activation. Transient overexpression of miR-25 inhibited TGF-β and its type 1 receptor (TGFBR1) mRNA expression, TGF-β-induced Smad2 phosphorylation and subsequent collagen1α1 induction in LX-2 cells. Pull-down experiments with biotinylated miR-25 revealed Notch signaling (co-)activators ADAM-17 and FKBP14 as miR-25 targets in HSCs. NanoString analysis confirmed miR-25 regulation of Notch- and Wnt-signaling pathways. Expression of Notch signaling pathway components and endogenous Notch1 signaling was downregulated in miR-25 overexpressing LX-2 cells, as were components of Wnt signaling such as Wnt5a. We propose that miR-25 acts as a negative feedback anti-fibrotic control during HSC activation by reducing the reactivity of HSCs to TGF-β-induced collagen expression and modulating the cross-talk between Notch, Wnt and TGF-β signaling.