Non-coding RNAs in hepatitis B or C-associated hepatocellular carcinoma: potential diagnostic and prognostic markers and therapeutic targets

Mechanistic target of rapamycin complex 1 orchestrates the interplay between hepatocytes and Kupffer cells to determine the outcome of immune-mediated hepatitis

The cell-cell interaction between hepatocytes and Kupffer cells (KCs) is crucial for maintaining liver homeostasis, and the loss of KCs and hepatocytes is known to represent a common pathogenic phenomenon in autoimmune hepatitis. Until now, the mechanisms of cell-cell interaction between hepatocytes and KCs involved in immune-mediated hepatitis remains unclear. Here we dissected the impact of activated mTORC1 on the cell-cell interaction of KCs and hepatocyte in immune-mediated hepatitis. In the liver from patients with AIH and mice administrated with Con-A, mTORC1 was activated in both KCs and hepatocytes. The activated mTORC1 signal in hepatocytes with Con-A challenge caused a markedly production of miR-329-3p. Upregulated miR-329-3p inhibited SGMS1 expression in KCs through paracrine, resulting in the death of KCs. Most of maintained KCs were p-S6 positive and distributed in hepatocyte mTORC1 negative area. The activation of mTORC1 enabled KCs expressed complement factor B (CFB) to enhance the complement alternative system, which produced more complement factors to aggravate liver injury. Our findings remonstrate a heterogeneous role of mTORC1 in specific cell type for maintaining tolerogenic liver environment, and will form the basis for the development of new interventions against immune-mediated hepatitis.

Investigation of the Association of miRNA-499, miRNA-146a, miRNA-196a2 Loci with Hepatocellular Carcinoma Risk: A Case-Control Study Involving 1507 Subjects

microRNAs' (miRNAs) loci may influence hepatocellular carcinoma (HCC) development. Many recent studies have assessed the relationship between miRNA-499, miRNA-146a, and miRNA-196a2 loci and HCC risk. However, the observed results are conflicting. A total of 584 HCC patients and 923 age- and sex-matched controls were recruited. The correlation of miRNA-499 rs3746444, miRNA-146a rs2910164, and miRNA-196a2 rs11614913 with HCC development was assessed. In the <53-year-old subgroup, a correlation of the rs2910164 locus with HCC risk was found (GG/CG vs. CC: adjusted p = 0.011, GG vs. CC: adjusted p = 0.021 and CG vs. CC: adjusted p = 0.027). The association between miRNA-146a rs2910164 and the risk of HCC was also found in the never smoking (GG/CG vs. CC: adjusted p = 0.011 and CG vs. CC: adjusted p = 0.018). Using false-positive report probability method and power value, we identified that miRNA-146a rs2910164 conferred a risk to HCC in the <53-year-old and never-smoking subgroups. In conclusion, this study indicates rs2910164 may be a risk factor for HCC, especially in the <53-year-old and never-smoking subgroups.

Exploration of invasive mechanisms via global ncRNA-associated virus-host crosstalk

Viral infection is a complex pathogenesis and the underlying molecular mechanisms remain poorly understood. In this study, an integrated multiple resources analysis was performed and showed that the cellular ncRNAs and proteins targeted by viruses were primarily "hubs" and "bottlenecks" in the human ncRNA/protein-protein interaction. The common proteins targeted by both viral ncRNAs and proteins tended to skew toward higher degrees and betweenness compared with other proteins, showed significant enrichment in the cell death process. Specifically, >800 pairs of human cellular ncRNAs and viral ncRNAs that exhibited a high degree of functional homology were identified, representing potential ncRNA-mediated co-regulation patterns of viral invasion. Additionally, clustering analysis further revealed several distinct viral clusters with obvious functional divergence. Overall, this is the first attempt to systematically explore the invasive mechanism via global ncRNA-associated virus-host crosstalk. Our results provide useful information in comprehensively understanding the viral invasive mechanism.

MicroRNA-122 in patients with hepatitis B and hepatitis B virus-associated hepatocellular carcinoma

Hepatitis B virus (HBV) infection is known as a serious problem in the domain of public health and approximately 350 million people across the world are affected with this infectious disease. As well, microRNAs are recognized as a type of small non-coding RNAs that can be widely used as a diagnostic biomarker and prognosis method of special diseases. In this respect, microRNA-122 or miR-122 can play a significant role in the pathogenesis of several hepatic diseases. Given the importance of microRNA-122 in the liver as well as its pathology, this study focused on the potential functions of microRNA-122 in pathogenesis, diagnosis, and treatment of HBV infection. In this regard, the findings of previous studies had indicated that expression of microRNA-122 in patients with HBV infection could be significantly deregulated. The results of this study were consistent with the idea that diagnosis and treatment of this infectious disease using microRNA-122 could be an efficient method.

Circular RNA profiling identifies circADAMTS13 as a miR-484 sponge which suppresses cell proliferation in hepatocellular carcinoma

Circular RNA (circRNA) can participate in various biological processes, including tumorigenesis, through their microRNA response elements. Alterations in circRNA profiles during hepatocellular carcinoma (HCC) progression and their clinical significance remain unclear. Here, we present extensive analysis of circRNA profiles in tumor and matched peritumor tissues collected from 10 HCC patients, conducted to identify circRNA related to HCC progression. A total of 42 dysregulated circRNA (38 down‐regulated and 4 up‐regulated) were identified in HCC tumor tissues compared with matched peritumor tissues, revealing the heterogeneity of circRNA profiles in HCC. CircADAMTS13, derived from Exon 13–14 of the ADAMTS13 gene, was significantly downregulated in HCC tumor tissues. Furthermore, clinicopathological analysis revealed that up‐regulation of circADAMTS13 was negatively associated with tumor size but positively associated with prognosis. In addition, overexpression of circADAMTS13 could markedly inhibit HCC cell proliferation in vitro. Bioinformatic analysis and luciferase reporter assays further revealed that circADAMTS13 directly interacts with microRNA (miR)‐484. Rescue experiments showed that miR‐484 mimics can reverse the tumor‐suppressing roles of circADAMTS13 in HCC. Therefore, our results demonstrated that circADAMTS13 can serve as a tumor suppressor during HCC progression via the functional pathway of sponging miR‐484.

Identification of potential prognostic microRNA biomarkers for predicting survival in patients with hepatocellular carcinoma

Background

The aim of the present study was to identify potential prognostic microRNA (miRNA) biomarkers for hepatocellular carcinoma (HCC) prognosis prediction based on a dataset from The Cancer Genome Atlas (TCGA).

Materials and methods

A miRNA sequencing dataset and corresponding clinical parameters of HCC were obtained from TCGA. Genome-wide univariate Cox regression analysis was used to screen prognostic differentially expressed miRNAs (DEMs), and multivariable Cox regression analysis was used for prognostic signature construction. Comprehensive survival analysis was performed to evaluate the prognostic value of the prognostic signature.

Results

Five miRNAs were regarded as prognostic DEMs and used for prognostic signature construction. The five-DEM prognostic signature performed well in prognosis prediction (adjusted P < 0.0001, adjusted hazard ratio = 2.249, 95% confidence interval =1.491-3.394), and time-dependent receiver-operating characteristic (ROC) analysis showed an area under the curve (AUC) of 0.765, 0.745, 0.725, and 0.687 for 1-, 2-, 3-, and 5-year HCC overall survival (OS) prediction, respectively. Comprehensive survival analysis of the prognostic signature suggests that the risk score model could serve as an independent factor of HCC and perform better in prognosis prediction than other traditional clinical indicators. Functional assessment of the target genes of hsa-mir-139 and hsa-mir-5003 indicates that they were significantly enriched in multiple biological processes and pathways, including cell proliferation and cell migration regulation, pathways in cancer, and the cyclic adenosine monophosphate (cAMP) signaling pathway.

Conclusion

Our study indicates that the novel miRNA expression signature may be a potential prognostic biomarker for HCC patients.

Diagnostic and Prognostic Value of MicroRNA in Viral Diseases

Virology is probably the most rapidly developing field within clinical laboratory medicine. Adequate diagnostic methods exist for the diagnostics of most acute viral infections. However, emergence of pathogenic viruses or virus strains and new disease associations of known viruses require the establishment of new diagnostic methods, sometimes very rapidly. In the field of chronic or persistent viral diseases, particularly those involving potential of malignant or fatal development, there is a constant need for improved differential diagnostics, monitoring, prognosis and risk assessment. Increasing understanding of disease pathogenesis also enables better patient management and personalized medicine, where companion diagnostics can offer precise and specific tools for individual care. Very often the new tools are offered by molecular diagnostic techniques, and this includes the detection of microRNAs (miRNAs). miRNAs are small regulatory RNA molecules, which regulate the expression of their target genes. They are encoded both by viruses and their host, and both can target either viral or cellular gene expression. In this review the diagnostic possibilities offered by miRNA will be discussed. The focus will be on selected viral and human miRNAs in viral diseases, and examples of miRNAs of putative diagnostic potential will be presented.

MetastamiRs: A promising choice for antihepatocellular carcinoma nucleic acid drug development

Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality worldwide, which can be explained at least in part by its propensity towards metastasis and the limited efficacy of adjuvant therapy. MetastamiRs are miRNAs that promote or suppress migration and metastasis of cancer cells, and their functional status is significantly correlated with HCC prognosis. Unlike targeted therapy, metastamiRs have the potential to target multiple genes and signaling pathways and dramatically suppress cancer metastasis. In this review, we discuss the regulatory role of metastamiRs in the HCC invasion-metastasis cascade. Moreover, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis has shown that many extensively studied metastamiRs target several critical signaling pathways and these have remarkable therapeutic potential in HCC. The information reviewed here may assist in further anti-HCC miRNA drug screening and development.

High Expression of the Newly Found Long Noncoding RNA Z38 Promotes Cell Proliferation and Oncogenic Activity in Breast Cancer

The aberrant expression of long noncoding RNAs (lncRNAs) has great impacts on cancer origination and progression. In the current study, a newly found lncRNA Z38, which was identified through combining experiments of suppression subtractive hybridization (SSH) and reverse dot-blotting, was found to have high expression in breast cancer. More importantly, inhibiting Z38 expression by gene silencing greatly suppressed breast cancer cell proliferation and tumorigenesis, and treatment with Z38 siRNAs significantly induced cell apoptosis and inhibited tumor growth. In conclusion, the newly found lncRNA Z38, which plays important roles in breast cancer, may act as a candidate biomarker and therapeutic target in carcinomas.

The regulatory roles of non-coding RNAs in nerve injury and regeneration

Non-coding RNAs (ncRNAs), especially microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), have attracted much attention since their regulatory roles in diverse cell processes were recognized. Emerging studies demonstrate that many ncRNAs are differentially expressed after injury to the nervous system, significantly affecting nerve regeneration. In this review, we compile the miRNAs and lncRNAs that have been reported to be dysregulated following a variety of central and peripheral nerve injuries, including acquired brain injury, spinal cord injury, and peripheral nerve injury. We also list investigations on how these miRNAs and lncRNAs exert the regulatory actions in neurodegenerative and neuroregenerative processes through different mechanisms involving their interaction with target coding genes. We believe that comprehension of the expression profiles and the possible functions of ncRNAs during the processes of nerve injury and regeneration will help understand the molecular mechanisms responsible for post-nerve-injury changes, and may contribute to the potential use of ncRNAs as a diagnostic marker and therapeutic target for nerve injury.

STAT3‑regulated long non‑coding RNAs lnc‑7SK and lnc‑IGF2‑AS promote hepatitis C virus replication

Long non‑coding RNAs (lncRNAs) are a class of RNAs that do not code protein but are important in diverse biological processes. In previous years, with the application of high‑throughput sequencing, a large number of lncRNAs associated with virus infections have been identified and intensively investigated, however, there are few studies examining the association between lncRNAs and HCV replication. Previous studies have demonstrated that signal transducer and activator of transcription 3 (STAT3) is activated by the hepatitis C virus (HCV) and in turn increases the replication of HCV. However, the detailed molecular mechanism is only partially understood. In the present study, using human lncRNA polymerase chain reaction (PCR) arrays, it was identified that lnc‑IGF2‑AS, lnc‑7SK, lnc‑SChLAP1 and lnc‑SRA1 are upregulated by STAT3. In addition, among these four lncRNAs, only lnc‑IGF2‑AS and lnc‑7SK were involved in HCV replication. Transfection of siRNA lnc‑7SK and siRNA lnc‑IGF2‑AS partially inhibited the replication of HCV in Huh7 cells. Data also indicated that when transfected with siRNA lnc‑7SK and siRNA lnc‑IGF2‑AS, the expression of phosphatidylinositol 4‑phosphate (PI4P), which was identified to be associated with HCV replication, was reduced. Thus, the present study identified two new types of lncRNAs, lnc‑IGF2‑AS and lnc‑7SK, which can be upregulated by STAT3 and are involved in HCV replication by regulating PI4P.

A Platform for Discovery and Quantification of Modified Ribonucleosides in RNA: Application to Stress-Induced Reprogramming of tRNA Modifications

Here we describe an analytical platform for systems-level quantitative analysis of modified ribonucleosides in any RNA species, with a focus on stress-induced reprogramming of tRNA as part of a system of translational control of cell stress response. This chapter emphasizes strategies and caveats for each of the seven steps of the platform workflow: (1) RNA isolation, (2) RNA purification, (3) RNA hydrolysis to individual ribonucleosides, (4) chromatographic resolution of ribonucleosides, (5) identification of the full set of modified ribonucleosides, (6) mass spectrometric quantification of ribonucleosides, (6) interrogation of ribonucleoside datasets, and (7) mapping the location of stress-sensitive modifications in individual tRNA molecules. We have focused on the critical determinants of analytical sensitivity, specificity, precision, and accuracy in an effort to ensure the most biologically meaningful data on mechanisms of translational control of cell stress response. The methods described here should find wide use in virtually any analysis involving RNA modifications.

Hepatitis B virus and microRNAs: Complex interactions affecting hepatitis B virus replication and hepatitis B virus-associated diseases

Chronic infection with the hepatitis B virus (HBV) is the leading risk factor for the development of hepatocellular carcinoma (HCC). With nearly 750000 deaths yearly, hepatocellular carcinoma is the second highest cause of cancer-related death in the world. Unfortunately, the molecular mechanisms that contribute to the development of HBV-associated HCC remain incompletely understood. Recently, microRNAs (miRNAs), a family of small non-coding RNAs that play a role primarily in post-transcriptional gene regulation, have been recognized as important regulators of cellular homeostasis, and altered regulation of miRNA expression has been suggested to play a significant role in virus-associated diseases and the development of many cancers. With this in mind, many groups have begun to investigate the relationship between miRNAs and HBV replication and HBV-associated disease. Multiple findings suggest that some miRNAs, such as miR-122, and miR-125 and miR-199 family members, are playing a role in HBV replication and HBV-associated disease, including the development of HBV-associated HCC. In this review, we discuss the current state of our understanding of the relationship between HBV and miRNAs, including how HBV affects cellular miRNAs, how these miRNAs impact HBV replication, and the relationship between HBV-mediated miRNA regulation and HCC development. We also address the impact of challenges in studying HBV, such as the lack of an effective model system for infectivity and a reliance on transformed cell lines, on our understanding of the relationship between HBV and miRNAs, and propose potential applications of miRNA-related techniques that could enhance our understanding of the role miRNAs play in HBV replication and HBV-associated disease, ultimately leading to new therapeutic options and improved patient outcomes.

Somatic mutations, viral integration and epigenetic modification in the evolution of hepatitis B virus-induced hepatocellular carcinoma

Liver cancer in men is the second leading cause of cancer death and hepatocellular carcinoma (HCC) accounts for 70%-85% of the total liver cancer worldwide. Chronic infection with hepatitis B virus (HBV) is the major cause of HCC. Chronic, intermittently active inflammation provides “fertile field” for “mutation, selection, and adaptation” of HBV and the infected hepatocytes, a long-term evolutionary process during HBV-induced carcinogenesis. HBV mutations, which are positively selected by insufficient immunity, can promote and predict the occurrence of HCC. Recently, advanced sequencing technologies including whole genome sequencing, exome sequencing, and RNA sequencing provide opportunities to better under-stand the insight of how somatic mutations, structure variations, HBV integrations, and epigenetic modifications contribute to HCC development. Genomic variations of HCC caused by various etiological factors may be different, but the common driver mutations are important to elucidate the HCC evolutionary process. Genome-wide analyses of HBV integrations are helpful in clarifying the targeted genes of HBV in carcinogenesis and disease progression. RNA sequencing can identify key molecules whose expressions are epigenetically modified during HCC evolution. In this review, we summarized the current findings of next generation sequencings for HBV-HCC and proposed a theory framework of Cancer Evolution and Development based on the current knowledge of HBV-induced HCC to characterize and interpret evolutionary mechanisms of HCC and possible other cancers. Understanding the key viral and genomic variations involved in HCC evolution is essential for generating effective diagnostic, prognostic, and predictive biomarkers as well as therapeutic targets for the interventions of HBV-HCC.

Heroin use promotes HCV infection and dysregulates HCV-related circulating microRNAs

Hepatitis C virus (HCV) infection is common among injection drug users (IDUs). There is accumulating evidence that circulating microRNAs (miRNAs) are associated with HCV infection and disease progression. The present study was undertaken to determine the in vivo impact of heroin use on HCV infection and HCV-related circulating miRNA expression. Using the blood specimens from four groups of the study subjects (HCV-infected individuals, heroin users with/without HCV infection, and healthy volunteers), we found that HCV-infected heroin users had significantly higher viral load than HCV-infected non-heroin users (p = 0.0004). Measurement of HCV-related circulating miRNAs in plasma showed that miRs-122, 141, 29a, 29b, and 29c were significantly increased in the heroin users with HCV infection, whereas miR-351, an HCV inhibitory miRNA, was significantly decreased in heroin users as compared to control subjects. Further investigation identified a negative correlation between the plasma levels of miR-29 family members and severity of HCV infection based on aspartate aminotransferase to platelet ratio index (APRI). In addition, heroin use and/or HCV infection also dysregulated a panel of plasma miRNAs. Taken together, these data for the first time revealed in vivo evidence that heroin use and/or HCV infection alter circulating miRNAs, which provides a novel mechanism for the impaired innate anti-HCV immunity among IDUs.

Epigenetic therapy as a novel approach in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common type of liver malignancy and one with high fatality. Its 5-year survival rate remains low and thus, there is a need for improvement of current treatment strategies as well as development of novel targeted methodologies in order to optimize existing therapeutic protocols. To this end, only recently, it was discovered that its pathophysiology also involves epigenetic alterations in DNA methylation, histone modifications and/or non-coding microRNA patterns. Unlike genetic events, epigenetic alterations are reversible and thus potentially considered to be an alternative option in cancer treatment protocols. In this review, we describe the general characteristics and resulted major alterations of the epigenetic machinery as well as current state of progress of epigenetic therapy (via different single or combinatorial experimental approaches) in HCC.

Predictive prognostic role of miR-181a with discrepancy in the liver and serum of genotype 4 hepatitis C virus patients

microRNA (miRNA) expression in organs does not always represent their quantity in serum. A disparity in the expression of miR-181a has been reported in the tissues and serum of hepatocellular carcinoma (HCC) patients. Since hepatitis C virus (HCV) is a major cause of HCC and miR-181a has never been studied in HCV, the present study aimed to investigate the miR-181a expression profile in genotype 4 (GT4)-HCV patients to evaluate whether this pattern is also apparent in HCV. RNA was extracted from liver tissues, peripheral mononuclear cells (PBMCs) and serum samples from GT4-HCV-infected patients and healthy donors to evaluate the relative miR-181a expression using quantitative reverse transcription-polymerase chain reaction. miR-181a was significantly higher in the serum of naïve patients compared to controls, and an inverse correlation with the viral load and liver enzymes was apparent. By contrast, no difference in miR-181a expression was observed in the liver tissues and PBMCs of patients compared to controls. This expression observed in HCV is conflicting to that previously reported in HCC. The study also demonstrates a significant upregulation of miR-181a post-interferon/ribavirin treatment in the serum of sustained virological responders (SVRs) compared to non-responders and treatment-naïve SVRs. In conclusion, miR-181a may be considered to be a possible prognostic marker in GT4-HCV infection.

Association of a potential functional pre-miR-218 polymorphism and its interaction with hepatitis B virus mutations with hepatocellular carcinoma risk

BACKGROUND & AIMS

MicroRNA-218 (miR-218) can function as a tumour suppressor and inactivate cancer-promoting inflammation. However, role of miR-218 on hepatocellular carcinoma (HCC) remains unclear. To determine the contribution of miR-218 genetic predisposition and its interaction with hepatitis B virus (HBV) mutations to HCC risk.

METHODS

rs11134527 located at putative promoter region of pre-miR-218 was genotyped in 1012 healthy controls, 302 hepatitis B surface antigen (HBsAg) seroclearance subjects and 2011 subjects with chronic HBV infection (1021 with HCC) using quantitative PCR. HBV mutation was determined by sequencing.

RESULTS

rs11134527 variant genotypes in dominant model was associated with HCC risk compared with all HCC-free subjects [odds ratio (OR) = 1.22, 95% confidence interval (CI) = 1.04-1.43], HCC-free HBsAg-positive subjects (OR = 1.23, 95% CI = 1.02-1.50) and HBsAg seroclearance subjects (OR = 1.45, 95% CI = 1.08-1.96), adjusting for age and gender, and also associated with the generation of HBV preS deletion in men (adjusted OR = 1.85, 95% CI = 1.23-2.76). In multivariate regression analyses, rs11134527 in dominant model was associated with HCC risk (OR = 1.50, 95% CI = 1.05-2.13), whereas its multiplicative interaction with viral mutation T1674C/G was inversely associated with HCC risk (OR = 0.44, 95% CI = 0.21-0.96), adjusting for covariates including HBV mutations in the enhancer II-precore region; its interaction with HBV preS1 start codon mutation was associated with HCC risk (OR = 4.44, 95% CI = 1.27-15.55), adjusting for covariates including HBV mutations in the preS region.

CONCLUSION

rs11134527 may be a novel genetic risk factor of HCC in HBV-exposed subjects, can facilitate HBV preS deletion generation and predispose the host to the effect of T1674C/G and preS1 start codon mutation in hepatocarcinogenesis.

Association of miRNA-122-binding site polymorphism at the interleukin-1 α gene and its interaction with hepatitis B virus mutations with hepatocellular carcinoma risk

This study was designed to investigate the contribution of miRNA-122-binding site polymorphism at the IL-1A gene and its multiplicative interactions with hepatitis B virus (HBV) mutations in the risk of hepatocellular carcinoma (HCC). A total of 1021 healthy controls, 302 HBV surface antigen (HBsAg) seroclearance subjects, and 2011 HBsAg-positive subjects (including 1021 HCC patients) were enrolled in this study. Quantitative PCR was used to genotype rs3783553. HBV mutations were determined by direct sequencing. Multivariate logistic regression analyses were performed to test the associations of rs3783553, mutations, and their interactions with the risk of HCC. No significant association was found between rs3783553 and the risk of HCC among healthy controls, HBsAg seroclearance subjects, HBsAg-positive subjects without HCC, and all controls. Additionally, rs3783553 was not significantly associated with chronic HBV infection, liver cirrhosis, HBV e antigen seroconversion, abnormal alanine aminotransferase, and high viral load (> 10(4) copies/ml). However, the TTCA insertion allele of rs3783553 was significantly associated with an increased frequency of HBV C7A mutation compared with homozygous TTCA deletion carriers [(del/ins + ins/ins) vs. del/del, adjusted odds ratio (OR)= 1.48, 95% confidence interval (CI)= 1.09-2.02, P = 0.013]. Multiplicative interaction of rs3783553 with HBV preS deletion significantly reduced the risk of HCC in males, with an adjusted OR of 0.64 (95% CI = 0.42-0.98; P = 0.041) after age and HBV genotype were adjusted. Although rs3783553 did not significantly affect genetic susceptibility to HBV-related HCC, its variant allele may predispose the host to selecting HBV C7A mutation during evolution and significantly reduce the risk of HCC caused by HBV preS deletion. This study provides an insight into the complex host-virus interaction in HBV-induced hepatocarcinogenesis and is helpful in determining HBsAg-positive subjects who are likely to develop HCC.

MicroRNAs and HIV-1 infection: antiviral activities and beyond

Cellular microRNAs (miRNAs) are an important class of small, non-coding RNAs that bind to host mRNAs based on sequence complementarity and regulate protein expression. They play important roles in controlling key cellular processes including cellular inception, differentiation and death. While several viruses have been shown to encode for viral miRNAs, controversy persists over the expression of a functional miRNA encoded in the human immunodeficiency virus type 1 (HIV-1) genome. However, it has been reported that HIV-1 infectivity is influenced by cellular miRNAs. Either through directly targeting the viral genome or by targeting host cellular proteins required for successful virus replication, multiple cellular miRNAs seem to modulate HIV-1 infection and replication. Perhaps as a survival strategy, HIV-1 may modulate proteins in the miRNA biogenesis pathway to subvert miRNA-induced antiviral effects. Global expression profiles of cellular miRNAs have also identified alterations of specific miRNAs post-HIV-1 infection both in vitro and in vivo (in various infected patient cohorts), suggesting potential roles for miRNAs in pathogenesis and disease progression. However, little attention has been devoted in understanding the roles played by these miRNAs at a cellular level. In this manuscript, we review past and current findings pertaining to the field of miRNA and HIV-1 interplay. In addition, we suggest strategies to exploit miRNAs therapeutically for curbing HIV-1 infectivity, replication and latency since they hold an untapped potential that deserves further investigation.

Non-coding RNAs in hepatitis C-induced hepatocellular carcinoma: Dysregulation and implications for early detection, diagnosis and therapy

Hepatitis C virus (HCV) infection is one of main causes of hepatocellular carcinoma (HCC) and the prevalence of HCV-associated HCC is on the rise worldwide. It is particularly important and helpful to identify potential markers for screening and early diagnosis of HCC among high-risk individuals with chronic hepatitis C, and to identify target molecules for the prevention and treatment of HCV-associated-HCC. Small non-coding RNAs, mainly microRNAs (miRNAs), and long non-coding RNAs (lncRNAs) with size greater than 200 nucleotides, are likely to play important roles in a variety of biological processes, including development and progression of HCC. For the most part their underlying mechanisms of action remain largely unknown. In recent years, with the advance of high-resolution of microarray and application of next generation sequencing techniques, a significant number of non-coding RNAs (ncRNAs) associated with HCC, particularly caused by HCV infection, have been found to be differentially expressed and to be involved in pathogenesis of HCV-associated HCC. In this review, we focus on recent studies of ncRNAs, especially miRNAs and lncRNAs related to HCV-induced HCC. We summarize those ncRNAs aberrantly expressed in HCV-associated HCC and highlight the potential uses of ncRNAs in early detection, diagnosis and therapy of HCV-associated HCC. We also discuss the limitations of recent studies, and suggest future directions for research in the field. miRNAs, lncRNAs and their target genes may represent new candidate molecules for the prevention, diagnosis and treatment of HCC in patients with HCV infection. Studies of the potential uses of miRNAs and lncRNAs as diagnostic tools or therapies are still in their infancy.

Cationic lipid nanoparticles for therapeutic delivery of siRNA and miRNA to murine liver tumor

miR-122, a liver-specific tumor suppressor microRNA, is frequently down-regulated in hepatocellular carcinoma (HCC). LNP-DP1, a cationic lipid nanoparticle formulation, was developed as a vehicle to restore deregulated gene expression in HCC cells by miR-122 delivery. LNP-DP1 consists of 2-dioleyloxy-N,N-dimethyl-3-aminopropane (DODMA), egg phosphatidylcholine, cholesterol and cholesterol-polyethylene glycol. In vitro, LNP-DP1-mediated transfection of a miR-122 mimic to HCC cells down-regulated miR-122 target genes by >95%. In vivo, siRNAs/miRNAs encapsulated in LNP-DP1 were preferentially taken up by hepatocytes and tumor cells in a mouse HCC model. The miR-122 mimic in LNP-DP1 was functional in HCC cells without causing systemic toxicity. To demonstrate its therapeutic potential, LNP-DP1 encapsulating miR-122 mimic was intratumorally injected and resulted in ~50% growth suppression of HCC xenografts within 30 days, which correlated well with suppression of target genes and impairment of angiogenesis. These data demonstrate the potential of LNP-DP1-mediated microRNA delivery as a novel strategy for HCC therapy.

FROM THE CLINICAL EDITOR

In this study, LNP-DP1 -a cationic lipid nanoparticle formulation -is reported as a vehicle to restore deregulated gene expression in hepatic carcinoma cells by siRNA and miRNA delivery using a mouse model. Further expansions to this study may enable transition to clinical trials of this system.

Associations of pri-miR-34b/c and pre-miR-196a2 polymorphisms and their multiplicative interactions with hepatitis B virus mutations with hepatocellular carcinoma risk

Background

Genetic polymorphisms of pri-miR-34b/c and pre-miR-196a2 have been reported to be associated with the susceptibility to cancers. However, the effect of these polymorphisms and their interactions with hepatitis B virus (HBV) mutations on the development of hepatocellular carcinoma (HCC) remains largely unknown. We hypothesized that these polymorphisms might interact with the HBV mutations and play a role in hepatocarcinogenesis.

Methods

Pri-miR-34b/c rs4938723 (T>C) and pre-miR-196a2 rs11614913 (T>C) were genotyped in 3,325 subjects including 1,021 HBV-HCC patients using quantitative PCR. HBV mutations were determined by direct sequencing. Contributions of the polymorphisms and their multiplicative interactions with gender or HCC-related HBV mutations to HCC risk were assessed using multivariate regression analyses.

Results

rs4938723 CC genotype was significantly associated with HCC risk compared to HBV natural clearance subjects, adjusted for age and gender (adjusted odds ratio [AOR] = 2.01, 95% confidence interval [CI] = 1.16–3.49). rs4938723 variant genotypes in dominant model significantly increased HCC risk in women, compared to female healthy controls (AOR = 1.85, 95% CI = 1.20–2.84) or female HCC-free subjects (AOR = 1.62, 95% CI = 1.14–2.31). rs4938723 CC genotype and rs11614913 TC genotype were significantly associated with increased frequencies of the HCC-related HBV mutations T1674C/G and G1896A, respectively. rs11614913 was not significantly associated with HCC risk, but its CC genotype significantly enhanced the effect of rs4938723 in women. In multivariate regression analyses, rs4938723 in dominant model increased HCC risk (AOR = 1.62, 95% CI = 1.05–2.49), whereas its multiplicative interaction with C1730G, a HBV mutation inversely associated with HCC risk, reduced HCC risk (AOR = 0.34, 95% CI = 0.15–0.81); rs11614913 strengthened the G1896A effect but attenuated the A3120G/T effect on HCC risk.

Conclusions

rs4938723 might be a genetic risk factor of HCC but its effect on HCC is significantly affected by the HBV mutations. rs11614913 might not be a HCC susceptible factor but it might affect the effects of the HBV mutations or rs4938723 on HCC risk.

Analysis of altered microRNA expression profiles in peripheral blood mononuclear cells from patients with primary biliary cirrhosis

BACKGROUND AND AIM

MicroRNA, as an important regulator of gene expression, has been found to be associated with several diseases. MicroRNA expression profiles have been identified in several autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis. However, the expression profile in peripheral blood mononuclear cells (PBMCs) from primary biliary cirrhosis (PBC) patients and the role of microRNA in PBC remained unclear. The present study aimed to explore abnormal microRNA regulation in PBC.

METHODS

MicroRNA array was performed in PBMCs obtained from PBC patients versus healthy controls. Then, six of the 17 differentially expressed microRNAs were confirmed using quantitative real-time polymerase chain reaction. Based on bioinformatics analysis, we identified the potential biological processes and significant signaling pathways affected by these microRNAs, and generated the microRNA-gene network.

RESULTS

According to microRNA array, a total of 17 microRNAs were found to be differentially expressed. Six microRNAs have been validated using quantitative real-time polymerase chain reaction, and the results were consistent with microRNA array analysis. The bioinformatics analysis showed that the potential target genes of these microRNAs were involved in cell proliferation, cell differentiation, apoptosis, and signal transduction. Similarly, these microRNAs also affected endocytosis, mitogen-activated protein kinase signaling pathway, transforming growth factor-β signaling pathway, Wnt signaling pathway, calcium signaling pathway, etc.

CONCLUSION

In the present study, 17 microRNAs were identified to be differentially expressed in PBMCs from PBC patients. Functional bioinformatics analysis demonstrated that prediction genes targeted by these microRNAs were involved in multiple biological processes and signaling pathways. The present study offers intriguing new perspectives on the involvement of microRNA in PBC, but the precise mechanisms need to be validated further.

MicroRNAs, hepatitis C virus, and HCV/HIV-1 co-infection: new insights in pathogenesis and therapy

MicroRNAs (miRNAs) can exert a profound effect on Hepatitis C virus (HCV) replication. The interaction of HCV with the highly liver-enriched miRNA, miR-122 represents one such unique example of viruses having evolved mechanism(s) to usurp the host miRNA machinery to support viral life cycle. Furthermore, HCV infection can also trigger changes in the cellular miRNA profile, which may ultimately contribute to the outcome of viral infection. Accumulating knowledge on HCV-host miRNA interactions has ultimately influenced the design of therapeutic interventions against chronic HCV infection. The importance of microRNA modulation in Human Immunodeficiency Virus (HIV-1) replication has been reported, albeit only in the context of HIV-1 mono-infection. The development of HCV infection is dramatically influenced during co-infection with HIV-1. Here, we review the current knowledge on miRNAs in HCV mono-infection. In addition, we discuss the potential role of some miRNAs, identified from the analyses of public data, in HCV/HIV-1 co-infection.

RNA-based diagnosis in a multicellular specimen by whole mount in situ hybridization using an RNA-specific probe

Recent RNA research has revealed the close involvement of various RNAs in cellular functions. RNAs are becoming the inevitable target molecules for research into details of gene expression. RNA and its related complexes are also promising targets for disease diagnosis. Multi cellular specimens such as organ tissues, histopathological specimens, and embryos are among the possible targets of RNA-based diagnostic techniques. In this report, we focused on a method that would provide such spatial and temporal information. We demonstrated that an RNA-specific probe (OMUpy2) was not only applicable to the detection of a specific mRNA in Drosophila embryos in a temporal and spatial manner but was also relatively quick and easy to use. The probe, OMUpy2, could be applied to other multi cellular systems for RNA-based diagnosis and research. The promising results of this manuscript show the great potential of RNA-based detection for both biological research and diagnostic medicine.

Challenges of incorporating gene expression data to predict HCC prognosis in the age of systems biology

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. The recurrence of HCC after curative treatments is currently a major hurdle. Identification of subsets of patients with distinct prognosis provides an opportunity to tailor therapeutic approaches as well as to select the patients with specific sub-phenotypes for targeted therapy. Thus, the development of gene expression profiles to improve the prediction of HCC prognosis is important for HCC management. Although several gene signatures have been evaluated for the prediction of HCC prognosis, there is no consensus on the predictive power of these signatures. Using systematic approaches to evaluate these signatures and combine them with clinicopathologic information may provide more accurate prediction of HCC prognosis. Recently, Villanueva et al^[13] developed a composite prognostic model incorporating gene expression patterns in both tumor and adjacent tissues to predict HCC recurrence. In this commentary, we summarize the current progress in using gene signatures to predict HCC prognosis, and discuss the importance, existing issues and future research directions in this field.