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

MicroRNA-3145 as a potential therapeutic target for hepatitis B virus: inhibition of viral replication via downregulation of HBS and HBX

Current treatments for hepatitis B virus (HBV), such as interferons and nucleic acid analogs, have limitations due to side effects like depression and the development of drug-resistant mutants, highlighting the need for new therapeutic approaches. In this study, we identified microRNA-3145 (miR-3145) as a host-derived miRNA with antiviral activity that is upregulated in primary hepatocytes during HBV infection. The expression of its precursor, pri-miR-3145, increased in response to the the virus infection, and miR-3145 downregulated the hepatitis B virus S (HBS) antigen and hepatitis B virus X (HBX), thereby inhibiting viral replication. The binding site for miR-3145 was located in the HBV polymerase (pol) region, as experimentally confirmed. Moreover, overexpression of HBS and HBX induced pri-miR-3145 expression through endoplasmic reticulum stress. The expression of pri-miR-3145 showed a strong correlation with the Nance-Horan syndrome-like 1 (NHSL1) gene, as it is encoded within an intron of NHSL1, and higher NHSL1 expression in hepatocellular carcinoma patients with HBV infection was associated with better prognosis. These findings suggest that miR-3145-3p, along with small molecules targeting its binding sites, holds promise as a potential therapeutic candidate for HBV treatment.

Unraveling the Mechanisms of MicroRNA in Suppressing Hepatitis B Virus Progression: A Comprehensive Review for Designing Treatment Strategies

: Liver cancer and cirrhosis caused by the Hepatitis B virus (HBV) remain significant global health challenges due to the virus's high prevalence and contagious nature. Hepatitis B virus can be transmitted through various means, leading to mild or severe liver disease. Although an effective prophylactic vaccine is available, it offers limited benefits for those already chronically infected. Current treatments often fail to consistently eliminate the virus and can cause severe adverse effects. In response to these challenges, researchers have begun exploring microRNAs (miRNAs) as novel therapeutic targets. Studying miRNA-virus interactions presents a promising opportunity to identify potential therapeutic targets. By manipulating host miRNAs, researchers aim to enhance antiviral defenses, restore cellular balance, and prevent viral replication. The text concludes by highlighting the potential for personalized medicine in Hepatitis B treatment, guided by individual miRNA profiles. Numerous studies have been conducted to understand how different miRNAs inhibit HBV replication, paving the way for the development of innovative and effective therapeutic strategies.

MicroRNA levels in patients with chronic hepatitis B virus and HIV coinfection in a high-prevalence setting; KwaZulu-Natal, South Africa

BACKGROUND

Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) co-infection are significant public health issues, despite the availability of an effective HBV vaccine for nearly three decades and the great progress that has been made in preventing and treating HIV. HBV and HIV both modulate micro-ribonucleic acids (microRNA) expression to support viral replication. The aim of this study was to describe the pattern of microRNA expression in patients coinfected with chronic HBV and HIV with varying disease severity, as indicated by Hepatitis B e antigen (HBeAg) status, HBV viral load, alanine transaminase (ALT) levels, and HIV viral load.

METHODS

Plasma microRNAs, specific to HBV, were measured by quantitative real-time polymerase chain reaction (qRT-PCR) in HBV and HIV-negative healthy controls (n = 23) and patients coinfected with chronic HBV-HIV (n = 50). MicroRNA expression levels were compared between patients with high vs low HBV viral load, HBeAg positive vs HBeAg negative, high vs low ALT levels, and high vs low HIV viral load. Additionally, HBV viral load, ALT levels, and HIV viral load were correlated with microRNA expression levels.

RESULTS

Significantly higher expression levels of selected microRNAs were observed in chronic HBV-HIV coinfected patients compared to healthy controls. Significantly higher expression levels of hsa-miR-122-5p, hsa-miR-192-5p, and hsa-miR-193b-3p were observed in patients with high HBV viral load compared with low HBV viral load patients, and the levels of these microRNAs were correlated with HBV viral load levels. Significantly higher levels of hsa-miR-15b-5p and hsa-miR-181b-5p were observed in HBeAg-negative patients.

CONCLUSION

This study demonstrates the potential use of hsa-miR-15b-5p, hsa-miR-122-5p, hsa-miR-181b-5p, hsa-miR-192-5p and hsa-miR-193b-3p as additional diagnostic biomarkers in chronic HBV disease progression.

Illuminating the pathogenic role of SARS-CoV-2: Insights into competing endogenous RNAs (ceRNAs) regulatory networks

The appearance of SARS-CoV-2 in 2019 triggered a significant economic and health crisis worldwide, with heterogeneous molecular mechanisms that contribute to its development are not yet fully understood. Although substantial progress has been made in elucidating the mechanisms behind SARS-CoV-2 infection and therapy, it continues to rank among the top three global causes of mortality due to infectious illnesses. Non-coding RNAs (ncRNAs), being integral components across nearly all biological processes, demonstrate effective importance in viral pathogenesis. Regarding viral infections, ncRNAs have demonstrated their ability to modulate host reactions, viral replication, and host-pathogen interactions. However, the complex interactions of different types of ncRNAs in the progression of COVID-19 remains understudied. In recent years, a novel mechanism of post-transcriptional gene regulation known as "competing endogenous RNA (ceRNA)" has been proposed. Long non-coding RNAs (lncRNAs), circular RNAs (circRNAs), and viral ncRNAs function as ceRNAs, influencing the expression of associated genes by sequestering shared microRNAs. Recent research on SARS-CoV-2 has revealed that disruptions in specific ceRNA regulatory networks (ceRNETs) contribute to the abnormal expression of key infection-related genes and the establishment of distinctive infection characteristics. These findings present new opportunities to delve deeper into the underlying mechanisms of SARS-CoV-2 pathogenesis, offering potential biomarkers and therapeutic targets. This progress paves the way for a more comprehensive understanding of ceRNETs, shedding light on the intricate mechanisms involved. Further exploration of these mechanisms holds promise for enhancing our ability to prevent viral infections and develop effective antiviral treatments.

Global blood miRNA profiling unravels early signatures of immunogenicity of Ebola vaccine rVSVΔG-ZEBOV-GP

The vectored Ebola vaccine rVSVΔG-ZEBOV-GP elicits protection against Ebola Virus Disease (EVD). In a study of forty-eight healthy adult volunteers who received either the rVSVΔG-ZEBOV-GP vaccine or placebo, we profiled intracellular microRNAs (miRNAs) from whole blood cells (WB) and circulating miRNAs from serum-derived extracellular vesicles (EV) at baseline and longitudinally following vaccination. Further, we identified early miRNA signatures associated with ZEBOV-specific IgG antibody responses at baseline and up to one year post-vaccination, and pinpointed target mRNA transcripts and pathways correlated to miRNAs whose expression was altered after vaccination by using systems biology approaches. Several miRNAs were differentially expressed (DE) and miRNA signatures predicted high or low IgG ZEBOV-specific antibody levels with high classification performance. The top miRNA discriminators were WB-miR-6810, EV-miR-7151-3p, and EV-miR-4426. An eight-miRNA antibody predictive signature was associated with immune-related target mRNAs and pathways. These findings provide valuable insights into early blood biomarkers associated with rVSVΔG-ZEBOV-GP vaccine-induced IgG antibody responses.

Antiviral therapy reduces hepatocellular carcinoma through suppressing hepatitis B virus replication may improve ER stress, mitochondrial and metabolic dysfunctions and decrease p62 in hybridized mice with single HBV transgene and miR-122

Hepatitis B virus (HBV) hijacks autophagy for its replication. Nucleos(t)ide analogs (NUCs) treatment suppressed HBV replication and reduced hepatocellular carcinoma (HCC) incidence. However, the use of NUCs in chronic hepatitis B (CHB) patients with normal or minimally elevated serum alanine aminotransferase (ALT) levels is still debated. Animal models are crucial for studying the unanswered issue and evaluating new therapies. MicroRNA-122 (miR-122), which regulates fatty acid and cholesterol metabolism, is downregulated during hepatitis and HCC progression. The reciprocal inhibition of miR-122 with HBV highlights its role in HCC development as a tumor suppressor. By crossbreeding HBV-transgenic mice with miR-122 knockout mice, we generated a hybrid mouse model with a high incidence of HCC up to 89% and normal ALT levels before HCC. The model exhibited early-onset hepatic steatosis, progressive liver fibrosis, and impaired late-phase autophagy. Metabolomics and microarray analysis identified metabolic signatures, including dysregulation of lipid metabolism, inflammation, genomic instability, the Warburg effect, reduced TCA cycle flux, energy deficiency, and impaired free radical scavenging. Antiviral treatment reduced HCC incidence in hybrid mice by approximately 30-35% compared to untreated mice. This effect was linked to the activation of ER stress-responsive transcription factor ATF4, clearance of autophagosome cargo p62, and suppression of the CHOP-mediated apoptosis pathway. In summary, this study suggests that despite minimal ALT elevation, HBV replication can lead to liver injury. Endoplasmic reticulum stress, reduced miR-122 levels, mitochondrial and metabolic dysfunctions, blocking protective autophagy resulting in p62 accumulation, apoptosis, fibrosis, and HCC. Antiviral may improve the above-mentioned pathogenesis through HBV suppression.

Dysregulated microRNAs as a biomarker for diagnosis and prognosis of hepatitis B virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a malignancy with a high incidence and fatality rate worldwide. Hepatitis B virus (HBV) infection is one of the most important risk factors for its occurrence and development. Early detection of HBV-associated HCC (HBV-HCC) can improve clinical decision-making and patient outcomes. Biomarkers are extremely helpful, not only for early diagnosis, but also for the development of therapeutics. MicroRNAs (miRNAs), a subset of non-coding RNAs approximately 22 nucleotides in length, have increasingly attracted scientists' attention due to their potential utility as biomarkers for cancer detection and therapy. HBV profoundly impacts the expression of miRNAs potentially involved in the development of hepatocarcinogenesis. In this review, we summarize the current progress on the role of miRNAs in the diagnosis and treatment of HBV-HCC. From a molecular standpoint, we discuss the mechanism by which HBV regulates miRNAs and investigate the exact effect of miRNAs on the promotion of HCC. In the near future, miRNA-based diagnostic, prognostic, and therapeutic applications will make their way into the clinical routine.

The interplay of long noncoding RNAs and hepatitis B virus

Hepatitis B Virus (HBV) infections remain a major global health burden with an estimated 296 million people living with a chronic infection and 884,000 HBV-related deaths annually. Notably, patients with a chronic hepatitis B (CHB) infection are at a 30-fold greater risk of developing hepatocellular carcinoma (HCC), the most common type of primary liver cancer, which is the 3rd deadliest cancer worldwide. Several groups have assessed HBV-related aberrant expression of host-cell long noncoding RNAs (lncRNAs) and how altered expression of specific lncRNAs affects HBV replication and progression to associated disease states. Given the challenges in establishing effective HBV models and analyzing transcriptomic data, this review focuses on lncRNA expression data primarily collected from clinical patient samples and primary human hepatocytes, with the subsequent mechanism of action analysis in cell lines or other model systems. Ultimately, understanding HBV-induced lncRNA-expression dysregulation could lead to new treatments and biomarkers for HBV infection and its associated diseases.

Micro RNAs—The Small Big Players in Hepatitis E Virus Infection: A Comprehensive Review

The molecular mechanism of hepatitis E virus (HEV) pathology is still unclear. The micro RNAs (miRNAs), of host or viral origin, interfere with virus replication and host environment in order to create an appropriate condition for the production of mature HEV progeny. Understanding the biogenesis and the interference of miRNAs with HEV will help to revile the mechanism of viral pathogenesis.

HBV cccDNA-A Culprit and Stumbling Block for the Hepatitis B Virus Infection: Its Presence in Hepatocytes Perplexed the Possible Mission for a Functional Cure

Hepatitis B virus infection (HBV) is still a big health problem across the globe. It has been linked to the development of liver cirrhosis and hepatocellular carcinoma and can trigger different types of liver damage. Existing medicines are unable to disable covalently closed circular DNA (cccDNA), which may result in HBV persistence and recurrence. The current therapeutic goal is to achieve a functional cure, which means HBV-DNA no longer exists when treatment stops and the absence of HBsAg seroclearance. However, due to the presence of integrated HBV DNA and cccDNA functional treatment is now regarded to be difficult. In order to uncover pathways for potential therapeutic targets and identify medicines that could result in large rates of functional cure, a thorough understanding of the virus' biology is required. The proteins of the virus and episomal cccDNA are thought to be critical for the management and support of the HBV replication cycle as they interact directly with the host proteome to establish the best atmosphere for the virus while evading immune detection. The breakthroughs of host dependence factors, cccDNA transcription, epigenetic regulation, and immune-mediated breakdown have all produced significant progress in our understanding of cccDNA biology during the past decade. There are some strategies where cccDNA can be targeted either in a direct or indirect way and are presently at the point of discovery or preclinical or early clinical advancement. Editing of genomes, techniques targeting host dependence factors or epigenetic gene maintenance, nucleocapsid modulators, miRNA, siRNA, virion secretory inhibitors, and immune-mediated degradation are only a few examples. Though cccDNA approaches for direct targeting are still in the early stages of development, the assembly of capsid modulators and immune-reliant treatments have made it to the clinic. Clinical trials are currently being conducted to determine their efficiency and safety in patients, as well as their effect on viral cccDNA. The influence of recent breakthroughs in the development of new treatment techniques on cccDNA biology is also summarized in this review.

The Computational Analysis of Single Nucleotide Associated with MicroRNA Affecting Hepatitis B Infection

BACKGROUND

MicroRNAs (miRNAs) have a pivotal role in Hepatitis B Virus (HBV) infection and its complications by targeting the cellular transcription factors required for gene expression or directly binding to HBV transcripts. Single Nucleotide Polymorphisms (SNPs) in miRNA genes affect their expression and the regulation of target genes, clinical course, diagnosis, and therapeutic interventions of HBV infection.

METHODS

Computational assessment and cataloging of miRNA gene polymorphisms targeting mRNA transcripts straightly or indirectly through the regulation of hepatitis B infection by annotating the functional impact of SNPs on mRNA-miRNA and miRNA-RBS (miRNA binding sites) interaction were screened by applying various universally available datasets such as the miRNA SNP3.0 software.

RESULTS

2987 SNPs were detected in 139 miRNAs affecting hepatitis B infection. Among them, 313 SNPs were predicted to have a significant role in the progression of hepatitis B infection. The computational analysis also revealed that 45 out of the 313 SNPs were located in the seed region and were more important than others. Has-miR-139-3p had the largest number of SNPs in the seed region (n=6). On the other hand, proteoglycans in cancer, adherens junction, lysine degradation, NFkappa B signaling cascade, ECM-receptor binding, viral carcinogenesis, fatty acid metabolism, TGF-beta signaling pathway, p53 signaling pathway, immune evasion related pathways, and fatty acid biosynthesis were the most important pathways affected by these 139 miRNAs.

CONCLUSION

The results revealed 45 SNPs in the seed region of 25 miRNAs as the catalog in miRNA genes that regulated the hepatitis B infection. The results also showed the most important pathways regulated by these miRNAs that can be targeted for therapeutic purposes.

The role of RNA binding proteins in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of overall cancer deaths worldwide with limited therapeutic options. Due to the heterogeneity of HCC pathogenesis, the molecular mechanisms underlying HCC development are not fully understood. Emerging evidence indicates that RNA-binding proteins (RBPs) play a vital role throughout hepatocarcinogenesis. Thus, a deeper understanding of how RBPs contribute to HCC progression will provide new tools for early diagnosis and prognosis of this devastating disease. In this review, we summarize the tumor suppressive and oncogenic roles of RBPs and their roles in hepatocarcinogenesis. The diagnostic and therapeutic potential of RBPs in HCC, including their limitations, are also discussed.

LncRNA CASC9 promotes proliferation, migration and inhibits apoptosis of hepatocellular carcinoma cells by down-regulating miR-424-5p

INTRODUCTION AND OBJECTIVES

CASC9 and miR-424-5p are closely related with hepatocellular carcinoma (HCC) progression. This study aimed to evaluate the effect of CASC9 involved with miR-424-5p on the development of HCC.

MATERIALS AND METHODS

qRT-PCR was performed to determine the mRNA expressions of CASC9 and miR-424-5p in HCC tissues/cells and adjacent normal tissues/human hepatic epithelial cells, and to analyze the relationship of CASC9 with the clinico-pathological characteristics and prognosis of HCC patients. Then, cell proliferation was measured by CCK-8 and¹ clone formation assays. Apoptosis of HCC cells was measured by flow cytometry. Besides, cell migration and invasion were determined by scratch wound-healing and Transwell assays, respectively. DIANA-LncBase V2 and dual luciferase reporter gene assay were used to verify the targeted relationship between CASC9 and miR-424-5p. Bcl-2, Bax and cleaved caspase-3 expressions were detected by Western blot.

RESULTS

Higher expression of CASC9 was observed in HCC tissues/ cells than in adjacent normal tissues/ human hepatic epithelial cells, and was closely linked to poor prognosis of HCC, tumor size, TNM stage, differentiation degree, lymph node metastasis and alpha-fetoprotein (AFP). Down-regulation of CASC9 decreased the proliferation, invasion and migration of HCC cells while enhancing apoptosis. Besides, CASC9 was negatively correlated with miR-424-5p. MiR-424-5p inhibitor enhanced cell proliferation, invasion and migration while decreasing apoptosis. Interestingly, siRNA-CASC9 partially offset the effects of miR-424-5p inhibitor on HCC cells.

CONCLUSION

CASC9 promoted proliferation, invasion and migration and inhibited apoptosis in HCC cells by inhibiting miR-424-5p.

Functional and Clinical Significance of Dysregulated microRNAs in Liver Cancer

Liver cancer is the leading cause of cancer-related mortality in the world. This mainly reflects the lack of early diagnosis tools and effective treatment methods. MicroRNAs (miRNAs) are a class of non-transcribed RNAs, some of which play important regulatory roles in liver cancer. Here, we discuss microRNAs with key impacts on liver cancer, such as miR-122, miR-21, miR-214, and miR-199. These microRNAs participate in various physiological regulatory pathways of liver cancer cells, and their modulation can have non-negligible effects in the treatment of liver cancer. We discuss whether these microRNAs can be used for better clinical diagnosis and/or drug development. With the advent of novel technologies, fast, inexpensive, and non-invasive RNA-based biomarker research has become a new mainstream approach. However, the clinical application of microRNA-based markers has been limited by the high sequence similarity among them and the potential for off-target problems. Therefore, researchers particularly value microRNAs that are specific to or have special functions in liver cancer. These include miR-122, which is specifically expressed in the liver, and miR-34, which is necessary for the replication of the hepatitis C virus in liver cancer. Clinical treatment drugs have been developed based on miR-34 and miR-122 (MRX34 and Miravirsen, respectively), but their side effects have not yet been overcome. Future research is needed to address these weaknesses and establish a feasible microRNA-based treatment strategy for liver cancer.

Critical Updates on Chronic Hepatitis B Virus Infection in 2021

Chronic hepatitis B virus (HBV) infection is a global healthcare burden in the form of chronic liver disease, cirrhosis, liver failure and liver cancer. There is no definite cure for the virus and even though extensive vaccination programs have reduced the burden of liver disease in the future population, treatment options to eradicate the virus from the host are still lacking. In this review, we discuss in detail current updates on the structure and applied biology of the virus in the host, examine updates to current treatment and explore novel and state-of-the-art therapeutics in the pipeline for management of chronic HBV. Furthermore, we also specifically review clinical updates on HBV-related acute on chronic liver failure (ACLF). Current treatments for chronic HBV infection have seen important updates in the form of considerations for treating patients in the immune tolerant phase and some clarity on end points for treatment and decisions on finite therapy with nucleos(t)ide inhibitors. Ongoing cutting-edge research on HBV biology has helped us identify novel target areas in the life cycle of the virus for application of new therapeutics. Due to improvements in the area of genomics, the hope for therapeutic vaccines, vector-based treatments and focused management aimed at targeting host integration of the virus and thereby a total cure could become a reality in the near future. Newer clinical prognostic tools have improved our understanding of timing of specific treatment options for the catastrophic syndrome of ACLF secondary to reactivation of HBV. In this review, we discuss in detail pertinent updates regarding virus biology and novel therapeutic targets with special focus on the appraisal of prognostic scores and treatment options in HBV-related ACLF.

Host Epigenetic Alterations and Hepatitis B Virus-Associated Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most frequent primary malignancy of the liver and a leading cause of cancer-related deaths worldwide. Although much progress has been made in HCC drug development in recent years, treatment options remain limited. The major cause of HCC is chronic hepatitis B virus (HBV) infection. Despite the existence of a vaccine, more than 250 million individuals are chronically infected by HBV. Current antiviral therapies can repress viral replication but to date there is no cure for chronic hepatitis B. Of note, inhibition of viral replication reduces but does not eliminate the risk of HCC development. HBV contributes to liver carcinogenesis by direct and indirect effects. This review summarizes the current knowledge of HBV-induced host epigenetic alterations and their association with HCC, with an emphasis on the interactions between HBV proteins and the host cell epigenetic machinery leading to modulation of gene expression.

HBV-Induced Increased N6 Methyladenosine Modification of PTEN RNA Affects Innate Immunity and Contributes to HCC

BACKGROUND AND AIMS

Epitranscriptomic modification of RNA has emerged as the most prevalent form of regulation of gene expression that affects development, differentiation, metabolism, viral infections, and most notably cancer. We have previously shown that hepatitis B virus (HBV) transcripts are modified by N6 methyladenosine (m⁶ A) addition. HBV also affects m⁶ A modification of several host RNAs, including phosphatase and tensin homolog (PTEN), a well-known tumor suppressor. PTEN plays a critical role in antiviral innate immunity and the development of hepatocellular carcinoma (HCC). Reports have shown that PTEN controlled interferon regulatory factor 3 (IRF-3) nuclear localization by negative phosphorylation of IRF-3 at Ser97, and PTEN reduced carcinogenesis by inhibiting the phosphatidylinositol-3-kinase (PI3K)/AKT pathway.

APPROACH AND RESULTS

Here, we show that HBV significantly increases the m⁶ A modification of PTEN RNA, which contributes to its instability with a corresponding decrease in PTEN protein levels. This is reversed in cells in which the expression of m⁶ A methyltransferases is silenced. PTEN expression directly increases activated IRF-3 nuclear import and subsequent interferon synthesis. In the absence of PTEN, IRF-3 dephosphorylation at the Ser97 site is decreased and interferon synthesis is crippled. In chronic HBV patient biopsy samples, m⁶ A-modified PTEN mRNA levels were uniformly up-regulated with a concomitant decrease of PTEN mRNA levels. HBV gene expression also activated the PI3K/AKT pathway by regulating PTEN mRNA stability in HCC cell lines.

CONCLUSIONS

The m⁶ A epitranscriptomic regulation of PTEN by HBV affects innate immunity by inhibiting IRF-3 nuclear import and the development of HCC by activating the PI3K/AKT pathway. Our studies collectively provide new insights into the mechanisms of HBV-directed immune evasion and HBV-associated hepatocarcinogenesis through m⁶ A modification of the host PTEN mRNAs.

Circulating non-coding RNAs as potential diagnostic biomarkers in liver diseases

The liver plays a principal role in the human body as a metabolic and detoxifying unit. Liver diseases are the world's major health problems and affect millions of people worldwide. Early detection of liver diseases is certainly effective in timely treatment and prevention of their progression. Liver injury is associated with significant alterations in immune responses and pattern changes in various tissue-related gene expressions and cytokine production. Increasing or decreasing the specific spectrum of non-coding RNAs in different phases of liver disease can be a criterion for diagnosis. Novel diagnostic biomarkers are needed for liver diseases. Currently, micro-RNAs (miRNAs) are known to play important roles in the diagnosis of liver diseases. Circulating biomarkers such as miRNA-assisted diagnosis can conceivably be helpful for the early treatment of liver diseases. In this review, we look at miRNAs and their potential applications in liver diseases as diagnostic biomarkers were investigated.

Role of ellagic acid for the prevention and treatment of liver diseases

Globally, one of the alarming problems is the prevalence and burden of liver diseases, which accounts for 2 million cases per year. Chronic liver aetiologies such as hepatitis infections, alcoholic or non-alcoholic liver disease, environmental agents, and drug-induced toxicity are invariably responsible for liver fibrosis progression to finally hepatocellular carcinoma. Current treatment options are unable to overwhelm and cure liver diseases. Emerging findings suggest researchers' interest in using evidence-based complementary medicine such as ellagic acid with extensive pharmacological properties. They include antioxidant, anti-inflammatory, anti-hyperlipidaemic, anti-viral, anti-angiogenic, and anticancer activity. The molecular functions elicited by ellagic acid include scavenging of free radicals, regulation of lipid metabolism, the prohibition of fibrogenesis response-mediating proteins, inhibits hepatic stellate cells and myofibroblasts, restrains hepatic viral replication, facilitates suppression of growth factors, regulates transcription factors, proinflammatory cytokines, augments the liver immune response, fosters apoptosis and inhibits cell proliferation in tumorigenic cells. This review will most notably focus on preclinical and clinical information based on currently available evidence to warrant ellagic acid's prospective role in preventing liver diseases.

Dysregulated microRNAs in Hepatitis B Virus-Related Hepatocellular Carcinoma: Potential as Biomarkers and Therapeutic Targets

MicroRNAs (miRNAs) are non-coding small RNAs that can function as gene regulators and are involved in tumorigenesis. We review the commonly dysregulated miRNAs in liver tumor tissues and plasma/serum of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) patients. The frequently reported up-regulated miRNAs in liver tumor tissues include miR-18a, miR-21, miR-221, miR-222, and miR-224, whereas down-regulated miRNAs include miR-26a, miR-101, miR-122, miR-125b, miR-145, miR-199a, miR-199b, miR-200a, and miR-223. For a subset of these miRNAs (up-regulated miR-222 and miR-224, down-regulated miR-26a and miR-125b), the pattern of dysregulated circulating miRNAs in plasma/serum is mirrored in tumor tissue based on multiple independent studies. Dysregulated miRNAs target oncogenes or tumor suppressor genes involved in hepatocarcinogenesis. Normalization of dysregulated miRNAs by up- or down-regulation has been shown to inhibit HCC cell proliferation or sensitize liver cancer cells to chemotherapeutic treatment. miRNAs hold as yet unrealized potential as biomarkers for early detection of HCC and as precision therapeutic targets, but further studies in diverse populations and across all stages of HCC are needed.

Potential of the ellagic acid-derived gut microbiota metabolite - Urolithin A in gastrointestinal protection

Urolithin A (UA) is a metabolic compound generated during the biotransformation of ellagitannins by the intestinal bacteria. The physiologically relevant micromolar concentrations of UA, achieved in the plasma and gastrointestinal tract (GI) after consumption of its dietary precursors, have been revealed to offer GI protection. The health benefit has been demonstrated to be principally related to anticancer and anti-inflammatory effects. UA has been shown to possess the capability to regulate multiple tumor and inflammatory signaling pathways and to modulate enzyme activity, including those involved in carcinogen biotransformation and antioxidant defense. The purpose of this review is to gather evidence from both in vitro and in vivo studies showing the potential of UA in GI protection alongside suggested mechanisms by which UA can protect against cancer and inflammatory diseases of the digestive tract. The data presented herein, covering both studies on the pure compound and in vivo generated UA form its natural precursor, support the potential of this metabolite in treatment interventions against GI ailments.

MiR-199a-5p regulates rat liver regeneration and hepatocyte proliferation by targeting TNF-α TNFR1/TRADD/CASPASE8/CASPASE3 signalling pathway

Abnormally expressed miR-199a-5p (miR-199a) has been frequently reported in multiple types of malignancies. Nevertheless, its effect in liver regeneration (LR) is largely still unclear. Herein, we investigated the function of miR-199a in hepatocyte proliferation during LR. As a result, miR-199a expression was significantly increased 12-30 h, in rat hepatic tissue, after partial hepatectomy (PH). The down-regulated expression of miR-199a inhibited proliferation as well as promoted cell apoptosis of BRL-3A. Additionally, TNF-α was found as a target of miR-199a. The administration of TNF-α siRNA regulated the effects of miR-199a on hepatocyte proliferation as well as miR-199a-modulated TNF-α/TNFR1/TRADD/CASPASE8/CASPASE3 signalling pathways. Taken together, these present findings suggested that miR-199a promoted hepatocyte proliferation as well as LR via targeting TNF-α/TNFR1/TRADD/CASPASE8/CASPASE3.

RNA-Seq Revealed a Circular RNA-microRNA-mRNA Regulatory Network in Hantaan Virus Infection

Hantaan virus (HTNV), a Hantavirus serotype that is prevalent in Asia, causes hemorrhagic fever with renal syndrome (HFRS) with high mortality in human race. However, the pathogenesis of HTNV infection remains elusive. Circular RNAs (circRNAs), a new type of non-coding RNAs, play a crucial role in various pathogenic processes. Nevertheless, circRNA expression profiles and their effects on pathogenesis of HTNV infection are still completely unknown. In the present study, RNA sequencing was performed to analyze the circRNA, microRNA (miRNA), and mRNA expression profiles in HTNV-infected and mock-infected human umbilical vein endothelial cells (HUVECs). A total of 70 circRNAs, 66 miRNAs, and 788 mRNAs were differently expressed. Several differentially expressed RNAs were validated by RT-qPCR. Moreover, we verified that some differentially expressed RNAs, such as circ_0000479, miR-149-5p, miR-330-5p, miR-411-3p, RIG-I, CMPK2, PARP10, and GBP1, promoted or inhibited HTNV replication. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis demonstrated that the host genes of differentially expressed circRNAs were principally involved in the innate immune response, the type I interferon (IFN) signaling pathway, and the cytokine-mediated signaling pathway. Additionally, the circRNA-miRNA-mRNA regulatory network was integrally analyzed. The data showed that there were many circRNA-miRNA-mRNA interactions in HTNV infection. By dual-luciferase reporter assay, we confirmed that circ_0000479 indirectly regulated RIG-I expression by sponging miR-149-5p, hampering viral replication. This study for the first time presents a comprehensive overview of circRNAs induced by HTNV and reveals that a network of enriched circRNAs and circRNA-associated competitive endogenous RNAs (ceRNAs) is involved in the regulation of HTNV infection, thus offering new insight into the mechanisms underlying HTNV-host interaction.

A novel miR-0308-3p revealed by miRNA-seq of HBV-positive hepatocellular carcinoma suppresses cell proliferation and promotes G1/S arrest by targeting double CDK6/Cyclin D1 genes

Background

Persistent infection with hepatitis B virus (HBV) accounts for the majority of hepatocellular carcinoma (HCC), but the molecular mechanisms underlying liver carcinogenesis are still not completely understood. Increasing evidence demonstrates that microRNAs (miRNAs) play significant functional roles in virus–host interactions. The aim of this study was to explore differentially expressed miRNA profiles and investigate the molecular mechanism of miR-0308-3p in HBV-positive HCC carcinogenesis.

Methods

High-throughput sequencing was used to detect novel miRNAs in three samples of HBV-positive HCC tissue compared to matched HBV-negative HCC tissue. The Cancer Genome Atlas (TCGA) database was used to mine miRNAs related to HBV-positive HCC. Bioinformatics analyses were conducted to predict the miRNAs’ possible biological and pathway regulatory functions. Quantitative polymerase chain reaction (qPCR) was then applied to evaluate the expression levels of randomly selected miRNAs. CCK-8 was used to measure cell proliferation and cell cycles were analyzed using flow cytometry. A dual luciferase reporter gene assay was used to confirm the downstream targets of miR-0308-3p.

Results

In total, there were 34 overlapping miRNAs in both our miRNA-seq data and the TCGA database. We found two overlapping miRNAs in both the HBV-positive HCC samples and the TCGA database, and 205 novel pre-miRNA sequences were predicted. miR-522 and miR-523 were markedly overexpressed in HBV-positive HCC and were associated with a significantly poorer long-term prognosis (miR-522, HR 2.19, 95% CI 1.33–3.6, p = 0.0015; miR-523HR 1.5, 95% CI 1–2.44, p = 0.0047). Of note, we found that the novel miR-0308-3p was markedly downregulated in HBV-positive HCC samples and HCC cancer cell lines compared with HBV-negative HCC samples and adjacent normal hepatic tissue. Moreover, elevated expression of miR-0308-3p was found to inhibit proliferation of cancer cells by promoting G1/S cell cycle arrest but did not influence the apoptosis of cancer cells. A dual luciferase reporter activity assay identified that miR-0308-3p acted directly on the target sequence of the CDK6 and Cyclin D1 mRNA 3ʹUTR to suppress CDK6 and Cyclin D1 expression.

Conclusions

MiR-0308-3p upregulation dramatically suppressed HCC cell proliferation and induced G1/S cell cycle arrest by directly targeting CDK6/Cyclin D1. These findings reveal a novel molecular mechanism for activation of G1/S arrest in HCC and may prove clinically useful for developing new therapeutic targets.

miR-130a alleviates neuronal apoptosis and changes in expression of Bcl-2/Bax and caspase-3 in cerebral infarction rats through PTEN/PI3K/Akt signaling pathway

Effect of micro ribonucleic acid (miR)-130a on neuronal apoptosis in rats with cerebral infarction (CI) was studied to explore whether phosphatase and tensin homolog deleted on chromosome ten (PTEN)/phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (Akt) is involved in the regulation of neuronal apoptosis. Thirty-six Sprague-Dawley (SD) rats were randomly divided into blank control group, model group and miR-130a low-expression group. miR-130a was determined by quantitative polymerase chain reaction (qPCR), the content of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-10 was detected using the enzyme-linked immunosorbent assay (ELISA) kits, and the neuronal apoptosis level in each group was determined through terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. The neurobehavioral score was significantly lower in model group than that in blank control group (P<0.01), while it was significantly higher in miR-130a low-expression group than that in model group (P<0.01). Compared with blank control group, the model group had obviously increased content of TNF-α and IL-6 (P<0.01), decreased content of IL-10 (P<0.01), more apoptotic neurons (P<0.01), higher expression of caspase-3 (P<0.01), and obviously lower Bcl-2/Bax (P<0.01). Moreover, expression of phosphorylated (p)-PTEN, PI3K and p-Akt in brain tissues was remarkably lower in the model group than those in the blank control group (P<0.01). The expression level of miR-130a in brain tissues of CI rats is significantly increased. miR-130a promotes the release of inflammatory factors and facilitates neuronal apoptosis through suppressing the PTEN/PI3K/Akt signaling pathway.

Addressing cultural diversity: the hepatitis B clinical specialist perspective

Objectives: Hepatitis B is a viral infection primarily affecting people from culturally diverse communities in Australia. While vaccination prevents infection, there is increasing mortality resulting from liver damage associated with chronic infection. Deficits in the national policy and clinical response to hepatitis B result in a low diagnosis rate, inadequate testing and diagnosis processes, and poor access to hepatitis B treatment services. While research identifies inadequate hepatitis B knowledge among people with the virus and primary health care workers, this project sought to identify how specialist clinicians in Australia negotiate cultural diversity, and provide often complex clinical information to people with hepatitis B. Design: A vignette was developed and presented to thirteen viral hepatitis specialist clinicians prior to an electronically recorded interview. Recruitment continued until saturation of themes was reached. Data were thematically coded into themes outlined in the interview schedule. Ethical approval for the research was provided by the La Trobe University Human Research Ethics Committee. Results: Key messages provided to patients with hepatitis B by clinical specialists were identified. These messages were not consistently provided to all patients with hepatitis B, but were determined on perceptions of patient knowledge, age and highest educational level. While the vignette stated that English was not an issue for the patient, most specialists identified the need for an interpreter. Combating stigma related to hepatitis B was seen as important by the specialists and this was done through normalising the virus. Having an awareness of different cultural understandings about hepatitis B specifically, and health and well-being generally, was noted as a communication strategy. Conclusion: Key core competencies need to be developed to deliver educational messages to people with hepatitis B within clinical encounters. The provision of adequate resources to specialist clinics will assist in addressing gaps in the clinical response to hepatitis B.

Serum miR-21 correlates with the histological stage of chronic hepatitis B-associated liver fibrosis

This study aimed to investigate the correlation between serum microRNA levels and histological stages of liver fibrosis in patients with chronic hepatitis B (CHB). A total of 28 patients with CHB who received liver biopsy at China Medical University Hospital between October 2012 and April 2013 were included in the study. The patients were divided into four groups according to the histological stages of liver fibrosis by using the METAVIR score. Serum microRNA levels were tested using quantitative real-time PCR after microRNA extraction from patients' serum. Of all the tested microRNAs, miR-21, miR-29, and miR-221 were expressed in the serum. The expression levels of serum miR-21 were significantly correlated with liver fibrosis stages (r = 0.420, P = 0.026). The expression levels of serum miR-21 were significantly correlated with cirrhosis (METAVIR F4 vs. F1-F3, r = 0.386, P = 0.043). The grades of serum miR-21 showed significant ordered differences among different stages of liver fibrosis (P = 0.019). However, miR-21 exhibited an inferior predictive performance for liver fibrosis F2-F4 (AUROC = 0.69) compared with other noninvasive markers of liver fibrosis, namely the aspartate aminotransferase (AST) to platelet ratio index (APRI) and Fibrosis-4 (FIB-4) score (AUROC = 0.83 and 0.86, respectively). Serum miR-21 correlated with the histological stage of liver fibrosis in patients with CHB. The predictive performance of serum miR-21 for the histological stage of liver fibrosis tended to be inferior to those of the APRI and FIB-4 score.

HBV-encoded miR-2 functions as an oncogene by downregulating TRIM35 but upregulating RAN in liver cancer cells

BACKGROUND

Hepatitis B virus (HBV) infection has been well established as a high-risk factor for the carcinogenesis of hepatocellular carcinoma (HCC). Cellular microRNA (miRNA) is involved in tumorigenesis by accelerating the malignant phenotype in HCC. However, whether HBV can encode miRNAs that contribute to HCC is not entirely clear.

METHODS

In this study, an miRNA encoded by HBV (HBV-miR-2) was identified by Solexa sequencing in HBV-positive HCC specimens and further verified in serum samples from HCC patients with HBV infection and in HBV-positive HCC cell lines. To evaluate the roles of HBV-miR-2 in liver cancer cells, we determined cell viability and migration/invasion ability by gain-of-function experiment in HBV(-) liver cancer cells (HepG2 and Huh7) and loss-of-function experiments in Huh7 cells stably expressing HBV-miR-2 (Huh7/HBV-miR-2 cells) and HepG2.2.15 cells. Furthermore, to elucidate the mechanism by which HBV-miR-2 work on cell malignancy, we identified and studied the effect of two target genes (TRIM35 and RAN) of HBV-miR-2 in liver cancer cells.

FINDINGS

We revealed that HBV-miR-2 promoted HCC cell growth ability by suppressing apoptosis and promoting migration and invasion by enhancing the epithelial-mesenchymal transition (EMT), functioning as an oncogene in the development of HBV-related HCC. Furthermore, we demonstrated that HBV-miR-2 suppresses the expression of TRIM35 but enhances RAN expression by targeting their 3'-untranslated regions (3'UTR) and that the ectopic expression of TRIM35 or knockdown of RAN counteracted the malignant phenotypes induced by HBV-miR-2.

INTERPRETATION

Our findings indicate that an HBV-encoded miRNA, HBV-miR-2, promotes oncogenic activity by downregulating TRIM35 expression and upregulating RAN expression in liver cancer cells, likely providing insight into tumorigenesis in HBV-related liver cancer. FUND: This work was supported in part by the National Natural Science Foundation of China (No: 81830094; 91629302; 31270818) and the Natural Science Foundation of Tianjin (No: 12JCZDJC25100).

miRNA-548ah promotes the replication and expression of hepatitis B virus by targeting histone deacetylase 4

AIM

Many studies have shown that some microRNAs (miRNAs) play an important role in the pathogenesis of chronic hepatitis B (CHB) infection. In this study, we aimed to explore the role and molecular mechanism of miRNA-548ah in the replication and expression of the hepatitis B virus (HBV).

MAIN METHODS

Overexpression and knockdown of miRNA-548ah were performed in three hepatoma cell lines with HBV replication and in a murine HBV model injected with adenovirus HBV vector. The effect of miRNA-548ah on its target gene, histone deacetylase (HDAC) 4, were confirmed in in vitro studies and further investigated in liver tissues from CHB patients.

KEY FINDINGS

miRNA-548ah significantly increased the expression of HBV in hepatoma cell lines and in a HBV mouse model. The expression level of covalently closed circular DNA (cccDNA) in the miRNA-548ah mimics group was significantly higher than the negative control group and significantly lower in the miRNA-548ah inhibitor group. The HBV core antigen promotes the expression of miRNA-548ah in hepatocytes. Finally, we observed a negative correlation between the expression of miRNA-548ah and HDAC4 in the liver tissue of patients with CHB.

SIGNIFICANCE

miRNA-548ah promoted the replication and expression of HBV through the regulation of the target gene, HDAC4. Inhibition of HDAC4 by miRNA-548ah might influence the deacetylation state of histones binding to cccDNA, thereby enhancing the replication of cccDNA. The HBV core antigen might increase the expression of miRNA-548ah. These results may provide new potential molecular targets for the prevention and treatment of CHB.

Prognosis, Prevention and Research Prospects of Progression to Severe Hepatitis B (Liver Failure)

This chapter describes the factors involved in the disease prognosis, parameters of outcome evaluations, principles and techniques for progression prevention. In last section, the future perspectives in both basic and clinical investigations towards unmet medical needs in AECHB and HBV ACLF are discussed.

Factors affecting the prognosis of patients with severe hepatitis B include those related to the virus (including viral load, HBeAg expression, and gene mutation), patient age, co-morbidity, TBil, INR, serum Cr, and the host genetic background. Indicators associated with patient prognosis include TBil, total cholesterol, albumin and prealbumin, hepatic encephalopathy, kidney damage, alpha-fetoprotein and vitamin D binding protein, blood sodium level, virus HBeAg expression and genotype, and blood glucose.

In addition to TBil, INR, hepatic encephalopathy, Cr level and AFP as indicators for prognosis of severe hepatitis, some other parameters such as clinical signs, symptoms, serum levels of total cholesterol and albumin and natrium, and coagulation factors are all valuable in assessment. The roles of cell apoptosis, liver regeneration and immunological parameters in assessing patient prognosis are under study. Prognostic evaluating systems include MELD score, MELD-Na score, iMELD score, KCI and CTP score.

Prevention of severe hepatitis B should be started in asymptomatic patients. Close observation, sufficient rest, adequate nutrition, meticulous nursing and psychological care, preventing and removing exacerbating factors, treating concomitant diseases, reasonable antiviral and comprehensive therapies are helpful to prevent CHB patients from developing to severe hepatitis. For patients who already have severe hepatitis B, the prevention and management of complications is important for lowering mortality rate.

New research directions in acute-on-chronic liver failure include: (1) Additional well controlled studies using present or new liver systems are warranted. Other approaches include the use of granulocyte colony stimulating factor to treat infections as well as the potential of use of stem cells to restore immune integrity and enhance liver regeneration. (2) Using new cell lines and animal models to understand the molecular biology of HBV, the immune response and to develop novel therapies. (3) Development of new anti-HBV strategies, e.g. silencing or remove cccDNA, enhancing immunologic clearance of HBV infection, inhibiting virus entry or HBc expression and using CRISP to disrupt cccDNA.

microRNAs: Key players in virus-associated hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is known as one of the major health problems worldwide. Pathological analysis indicated that a variety of risk factors including genetical (i.e., alteration of tumor suppressors and oncogenes) and environmental factors (i.e., viruses) are involved in beginning and development of HCC. The understanding of these risk factors could guide scientists and clinicians to design effective therapeutic options in HCC treatment. Various viruses such as hepatitis B virus (HBV) and hepatitis C virus (HCV) via targeting several cellular and molecular pathways involved in HCC pathogenesis. Among various cellular and molecular targets, microRNAs (miRNAs) have appeared as key players in HCC progression. miRNAs are short noncoding RNAs which could play important roles as oncogenes or tumor suppressors in several malignancies such as HCC. Deregulation of many miRNAs (i.e., miR-222, miR-25, miR-92a, miR-1, let-7f, and miR-21) could be associated with different stages of HCC. Besides miRNAs, exosomes are other particles which are involved in HCC pathogenesis via targeting different cargos, such as DNAs, RNAs, miRNAs, and proteins. In this review, we summarize the current knowledge of the role of miRNAs and exosomes as important players in HCC pathogenesis. Moreover, we highlighted HCV- and HBV-related miRNAs which led to HCC progression.

Identification of Differentially Expressed Non-coding RNA in Porcine Alveolar Macrophages from Tongcheng and Large White Pigs Responded to PRRSV

Porcine reproductive and respiratory syndrome (PRRS) is one of the most ruinous diseases in pig production. Our previous work showed that Tongcheng pigs (TC) were less susceptible to PRRS virus (PRRSV) than Large White (LW) pigs. To elucidate the difference in PRRSV resistance between the two breeds, small RNA-seq and ribo-zero RNA-seq were used to identify differentially expressed non-coding RNAs (including miRNAs and lincRNAs) responded to PRRSV in porcine alveolar macrophages (PAMs) from TC and LW pigs. Totally, 250 known mature miRNAs were detected. For LW pigs, there were 44 down-regulated and 67 up-regulated miRNAs in infection group; while for TC pigs, 12 down-regulated and 23 up-regulated miRNAs in TC infection group were identified. The target genes of the common differentially expressed miRNAs (DEmiRNAs) in these two breeds were enriched in immune-related processes, including apoptosis process, inflammatory response, T cell receptor signaling pathway and so on. In addition, 5 shared DEmiRNAs (miR-181, miR-1343, miR-296-3p, miR-199a-3p and miR-34c) were predicted to target PRRSV receptors, of which miR-199a-3p was validated to inhibit the expression of CD151. Interestingly, miR-378 and miR-10a-5p, which could inhibit PRRSV replication, displayed higher expression level in TC control group than that in LW control group. Contrarily, miR-145-5p and miR-328, which were specifically down-regulated in LW pigs, could target inhibitory immunoreceptors and may involve in immunosuppression caused by PRRSV. This indicates that DEmiRNAs are involved in the regulation of the immunosuppression and immune escape of the two breeds. Furthermore, we identified 616 lincRNA transcripts, of which 48 and 30 lincRNAs were differentially expressed in LW and TC pigs, respectively. LincRNA TCONS_00125566 may play an important role in the entire regulatory network, and was predicted to regulate the expression of immune-related genes through binding with miR-1343 competitively. In conclusion, this study provides an important resource for further revealing the interaction between host and virus, which will specify a new direction for anti-PRRSV research.

Exosomes derived from HBV-associated liver cancer promote chemoresistance by upregulating chaperone-mediated autophagy

Liver cancer, which is the second leading cause of tumor-associated mortality, is of great concern worldwide due to its resistance to chemotherapeutic drugs. Transcatheter arterial chemoembolization (TACE) has previously been used as a treatment for unresectable liver tumors in China; however, the response to TACE treatment differs between patients. It has been reported that hepatitis B virus (HBV)-as sociated tumors are less sensitive to TACE treatment compared with non-HBV-associated liver cancer. Previous studies have demonstrated that exosomes serve a crucial role in hepatic carcinoma chemoresistance. We therefore hypothesized that HBV may modulate chemosensitivity via exosomes. The aim of the present study was to investigate how exosomes affect chemoresistance by assessing their role in chaperone-mediated autophagy (CMA)-dependent chemoresistance in HBV-associated liver cancer. Iconography data from HBV-positive and HBV-negative patients with hepatic carcinoma receiving TACE treatment were assessed, and it was revealed that the tumor volume was decreased in the patients with non-HBV-associated liver cancer compared with that in the patients with HBV-associated tumors following TACE therapy. Furthermore, it was revealed that exosomes from HBV-infected liver cancer cells were able to downregulate cell apoptosis when treated with oxaliplatin compared with exosomes from normal HepG2 cells. Furthermore, the results demonstrated that HBV-associated exosomes modulate cell death via activating the CMA pathway, and its key molecule, lysosome-associated membrane protein (Lamp2a), was also upregulated. Lamp2a-knockdown was also found to reverse anti-apoptotic effects in liver cancer. Taken together, the results of the present study suggest that chemoresistance in patients with HBV-associated hepatic tumors may be mediated by exosomes, and thus may provide a basis for the development of novel treatment strategies for chemoresistant liver cancer.

Dysregulation of miRNA in chronic hepatitis B is associated with hepatocellular carcinoma risk after nucleos(t)ide analogue treatment

Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC). Nucleos(t)ide analogue (NA) therapy effectively reduces the incidence of HCC, but it does not completely prevent the disease. Here, we show that dysregulation of microRNAs (miRNAs) is involved in post-NA HCC development. We divided chronic hepatitis B (CHB) patients who received NA therapy into two groups: 1) those who did not develop HCC during the follow-up period after NA therapy (no-HCC group) and 2) those who did (HCC group). miRNA expression profiles were significantly altered in CHB tissues as compared to normal liver, and the HCC group showed greater alteration than the no-HCC group. NA treatment restored the miRNA expression profiles to near-normal in the no-HCC group, but it was less effective in the HCC group. A number of miRNAs implicated in HCC, including miR-101, miR-140, miR-152, miR-199a-3p, and let-7g, were downregulated in CHB. Moreover, we identified CDK7 and TACC2 as novel target genes of miR-199a-3p. Our results suggest that altered miRNA expression in CHB contributes to HCC development, and that improvement of miRNA expression after NA treatment is associated with reduced HCC risk.

Study of miR-143 expression in stomach cancer

The present study was planned to investigate miR-143 expression during stomach cancer. The study explored the relationship between miR-143 expression and clinicopathological characteristics including proliferation, migration and apoptosis of stomach cancer cells. Sixty-three samples from each of stomach cancer tissue and surrounding tissue were obtained. Total RNA was extracted. The expression levels of miR-143 from stomach cancer tissue as well as from surrounding tissue were measured by semi-quantitative PCR. The effects of miR-143 overexpression on the migration of stomach cancer cells were examined by Transwell assay. The effects of miR-143 overexpression on the apoptosis of stomach cancer cells were examined by flow cytometer. The expression level of miR-143 was significantly decreased in stomach cancer tissues in comparison to surrounding tissues (P<0.01). Moreover, the expression of miR-143 related well with the tumor size, TNM stage, lymphatic metastasis and relapse (P<0.01). On the other hand, stomach cancer cell line with overexpression of miR-143, showed significant decline in proliferation rate and migration rate comparison to control cells (P<0.01). However, it showed significant higher in apoptosis rate (P<0.01). The present study concluded that expression of miR-143 is low during stomach cancer. Further, higher expression levels of miR-143 have the ability to decline proliferation and migration of stomach cancer cells. In this manner, the expression level of miR-143 could be used as an important factor to determine the severity of stomach cancer.

Correlation Between the Hepatic Expression of Human MicroRNA hsa-miR-125a-5p and the Progression of Fibrosis in Patients With Overt and Occult HBV Infection

AIMS

To evaluate the correlation between the hepatic expression pattern of hsa-miR-125a-5p and HBV-DNA and the progression of fibrosis in patients with overt or occult HBV infection.

METHODS

We enrolled all the HBsAg-positive treatment naive patients (overt HBV group) and all the HBsAg-negative patients with hepatocellular carcinoma and with a positive HBV-DNA in their hepatic tissue (occult HBV group), who underwent a diagnostic liver biopsy between April 2007 and April 2015. Tissue concentrations of HBV-DNA and hsa-miR-125a-5p were then analyzed by real-time quantitative PCR. Necroinflammatory activity and fibrosis were evaluated according to the Ishak score.

RESULTS

During the study period, we enrolled 64 patients with overt and 10 patients with occult HBV infection. In the overt HBV group, 35 of 64 (54.7%) showed a mild fibrosis (staging 0-2), 17 (26.6%) a moderate fibrosis (staging 3-4), while the remaining 12 (18.7%) had a cirrhosis. All patients in the occult HBV group were cirrhotic. Patients with more advanced fibrosis stage showed a higher mean age when compared with those with mild (p < 0.00001) or moderate fibrosis (p < 0.00001) and were more frequently male than patients with staging 0-2 (p = 0.04). Similarly, patients with occult B infection were older than HBsAg-positive patients. Liver concentrations of miR-125a-5p were significantly higher in patients with cirrhosis (9.75 ± 4.42 AU) when compared with patients with mild (1.39 ± 0.94, p = 0.0002) or moderate fibrosis (2.43 ± 2.18, p = 0.0006) and were moderately higher in occult than in overt HBV infection (p = 0.09). Moreover, we found an inverse correlation, although not statistically significant, between the tissue HBV-DNA levels and the staging of fibrosis.

CONCLUSION

This study suggests a correlation between the tissue expression of hsa-miR-125a-5p and the progression of liver damage in a group of patients with occult or overt HBV infection. If confirmed, these data suggest the hsa-miR-125a-5p may be a novel biomarker of hepatic damage.

Hepatitis B virus pathogenesis: Fresh insights into hepatitis B virus RNA

Hepatitis B virus (HBV) is still a worldwide health concern. While divergent factors are involved in its pathogenesis, it is now clear that HBV RNAs, principally templates for viral proteins and viral DNAs, have diverse biological functions involved in HBV pathogenesis. These functions include viral replication, hepatic fibrosis and hepatocarcinogenesis. Depending on the sequence similarities, HBV RNAs may act as sponges for host miRNAs and may deregulate miRNA functions, possibly leading to pathological consequences. Some parts of the HBV RNA molecule may function as viral-derived miRNA, which regulates viral replication. HBV DNA can integrate into the host genomic DNA and produce novel viral-host fusion RNA, which may have pathological functions. To date, elimination of HBV-derived covalently closed circular DNA has not been achieved. However, RNA transcription silencing may be an alternative practical approach to treat HBV-induced pathogenesis. A full understanding of HBV RNA transcription and the biological functions of HBV RNA may open a new avenue for the development of novel HBV therapeutics.

The Role of miRNAs in Virus-Mediated Oncogenesis

To date, viruses are reported to be responsible for more than 15% of all tumors worldwide. The oncogenesis could be influenced directly by the activity of viral oncoproteins or by the chronic infection or inflammation. The group of human oncoviruses includes Epstein–Barr virus (EBV), human papillomavirus (HPV), hepatitis B virus (HBV), hepatitis C virus (HCV), human herpesvirus 8 (HHV-8) or polyomaviruses, and transregulating retroviruses such as HIV or HTLV-1. Most of these viruses express short noncoding RNAs called miRNAs to regulate their own gene expression or to influence host gene expression and thus contribute to the carcinogenic processes. In this review, we will focus on oncogenic viruses and summarize the role of both types of miRNAs, viral as well as host’s, in the oncogenesis.

Viral MicroRNAs, Host MicroRNAs Regulating Viruses, and Bacterial MicroRNA-Like RNAs

As masters of genome-wide regulation, miRNAs represent a key component in the complex architecture of cellular processes. Over the last decade, it has become increasingly apparent that miRNAs have many important roles in the development of disease and cancer. Recently, however, their role in viral and bacterial gene regulation as well as host gene regulation during disease progression has become a field of interest. Due to their small size, miRNAs are the ideal mechanism for bacteria and viruses that have limited room in their genomes, as a single miRNA can target up to ~30 genes. Currently, only a limited number of miRNA and miRNA-like RNAs have been found in bacteria and viruses, a number that is sure to increase rapidly in the future. The interactions of these small noncoding RNAs in such primitive species have wide-reaching effects, from increasing viral and bacterial proliferation, better responses to stress, increased virulence, to manipulation of host immune responses to provide a more ideal environment for these pathogens to thrive. Here, we explore those roles to obtain a better grasp of just how complicated disease truly is.

gga-miR-155 Enhances Type I Interferon Expression and Suppresses Infectious Burse Disease Virus Replication via Targeting SOCS1 and TANK

Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive avian disease caused by IBD virus (IBDV). MicroRNAs (miRNAs) are involved in host-pathogen interactions and innate immune response to viral infection. However, the role of miRNAs in host response to IBDV infection is not clear. We report here that gga-miR-155 acts as an anti-virus host factor inhibiting IBDV replication. We found that transfection of DF-1 cells with gga-miR-155 suppressed IBDV replication, while blockage of the endogenous gga-miR-155 by inhibitors enhanced IBDV replication. Furthermore, our data showed that gga-miR-155 enhanced the expression of type I interferon in DF-1 cells post IBDV infection. Importantly, we found that gga-miR-155 enhanced type I interferon expression via targeting SOCS1 and TANK, two negative regulators of type I IFN signaling. These results indicate that gga-miR-155 plays a critical role in cell response to IBDV infection.

miR-146 promotes HBV replication and expression by targeting ZEB2

Hepatitis B virus (HBV) is associated with the development of a wide spectrum of liver diseases. The involvement of miRNAs in HBV replication is being gradually identified. Among these miRNAs, miR-146a expression was found to be positively correlated with HBV replication levels. However, the regulatory relationship between miR-146a and HBV replication is still unclear. In the present study, miR-146a was upregulated in HBV-expressing HepG2.2.15 cells compared with HepG2 cells. Overexpression of miR-146a or knockdown of Zinc finger E-box-binding homeobox 2 (ZEB2) promoted HBV replication and expression, while downregulation of miR-146a or overexpression of ZEB2 suppressed HBV replication and expression. In addition, miR-146a was demonstrated to directly target ZEB2. Furthermore, ZEB2 silencing abated anti-miR-146a-induced inhibition on HBV replication and expression. These findings suggested that miR-146a promoted HBV replication by targeting ZEB2, providing a new antiviral strategy for HBV infection.

Nuclear IKKα mediates microRNA-7/-103/107/21 inductions to downregulate maspin expression in response to HBx overexpression

Maspin is a tumor suppressor that stimulates apoptosis and inhibits metastasis in various cancer types, including hepatocellular carcinoma (HCC). Our previous study has demonstrated that HBx induced microRNA-7, 103, 107, and 21 expressions to suppress maspin expression, leading to metastasis, chemoresistance, and poor prognosis in HCC patients. However, it remains unclear how HBx elicits these microRNA expressions. HBx has been known to induce aberrant activation and nuclear translocation of inhibitor-κB kinase-α (IKKα) to promote HCC progression. In this study, our data further revealed that nuclear IKKα expression was inversely correlated with maspin expression in HBV-associated patients. Nuclear IKKα but not IKKβ reduced maspin protein and mRNA expression, and inhibition of IKKα reverses HBx-mediated maspin downregulation and chemoresistance. In response to HBx overexpression, nuclear IKKα was further demonstrated to induce the gene expressions of microRNA-7, −103, −107, and −21 by directly targeting their promoters, thereby leading to maspin downregulation. These findings indicated nuclear IKKα as a critical regulator for HBx-mediated microRNA induction and maspin suppression, and suggest IKKα as a promising target to improve the therapeutic outcome of HCC patients.

Association of single nucleotide polymorphisms in microRNAs with susceptibility to hepatitis B virus infection and HBV-related liver complications: A study in a Saudi Arabian population

The aim of this study was to evaluate the association of 10 SNPs in different microRNAs (miRNAs) with susceptibility to hepatitis B virus (HBV) infection, HBV clearance, persistence of chronic HBV infection, and progression to liver cirrhosis and hepatocellular carcinoma (HCC). Patients were categorized into the following groups: inactive HBV carrier, active HBV carrier, HBV-cleared subject and cirrhosis+HCC. Samples were analysed for 10 SNPs in microRNAs using either PCR-based genotyping or the TaqMan assay. We found that rs1358379 was associated with susceptibility to HBV infection, HBV clearance, persistent chronic HBV infection and liver cirrhosis+HCC. In addition, we found that rs2292832 and rs11614913 were associated with risk of HBV infection, viral clearance and cirrhosis+HCC, whereas rs2910164 was associated with proneness to HBV infection, and ability to clear the virus. There was evidence of associations between rs6505162 and HBV clearance and the development of liver disease, whereas a single association was found between rs2289030 and HBV clearance. Similarly, rs7372209 and rs4919510 were specifically associated with the development of HBV-induced liver complications. SNPs in miRNAs affect the susceptibility, clearance and progression of HBV infection in Saudi Arabian patients. We found, using Gene Ontology or pathway analyses, that these genes may contribute to the pathophysiology of HBV infection and related liver complications. However, differences in the association of examined SNPs with various clinical stages indicate variations in the respective functional roles of these polymorphisms and their miRNAs, and thus, further investigation to fully explore their therapeutic potential is warranted.

Viral Oncology: Molecular Biology and Pathogenesis

Oncoviruses are implicated in approximately 12% of all human cancers. A large number of the world's population harbors at least one of these oncoviruses, but only a small proportion of these individuals go on to develop cancer. The interplay between host and viral factors is a complex process that works together to create a microenvironment conducive to oncogenesis. In this review, the molecular biology and oncogenic pathways of established human oncoviruses will be discussed. Currently, there are seven recognized human oncoviruses, which include Epstein-Barr Virus (EBV), Human Papillomavirus (HPV), Hepatitis B and C viruses (HBV and HCV), Human T-cell lymphotropic virus-1 (HTLV-1), Human Herpesvirus-8 (HHV-8), and Merkel Cell Polyomavirus (MCPyV). Available and emerging therapies for these oncoviruses will be mentioned.

Involvement of inflammation and its related microRNAs in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most commonly diagnosed type of cancer. The tumor inflammatory microenvironment regulates almost every step towards liver tumorigenesis and subsequent progression, and regulation of the inflammation-related signaling pathways, cytokines, chemokines and non-coding RNAs influences the proliferation, migration and metastasis of liver tumor cells. Inflammation fine-tunes the cancer microenvironment to favor epithelial-mesenchymal transition, in which cancer stem cells maintain tumorigenic potential. Emerging evidence points to inflammation-related microRNAs as crucial molecules to integrate the complex cellular and molecular crosstalk during HCC progression. Thus understanding the mechanisms by which inflammation regulates microRNAs might provide novel and admissible strategies for preventing, diagnosing and treating HCC. In this review, we will update three hypotheses of hepatocarcinogenesis and elaborate the most predominant inflammation signaling pathways, i.e. IL-6/STAT3 and NF-κB. We also try to summarize the crucial tumor-promoting and tumor-suppressing microRNAs and detail how they regulate HCC initiation and progression and collaborate with other critical modulators in this review.

Expression Profiling of Cellular MicroRNA in Asymptomatic HBsAg Carriers and Chronic Hepatitis B Patients

Background

MicroRNAs (miRNAs) may serve as potential molecular markers to predict liver injury resulting from chronic hepatitis B (CHB). In the present study, we want to study the expression profile and clinical significance of miRNAs at different stages of CHB virus infection.

Methods

Using miRNA microarray, we investigated the global expression profiles of cellular miRNA in asymptomatic hepatitis B antigen carriers (ASCs) and CHB patients, compared with healthy controls (HCs).

Results

We identified 79 and 203 differentially expressed miRNAs in the peripheral blood mononuclear cells of ASCs and CHB patients compared to HCs, respectively. Some of these miRNAs were common to ASCs and CHB patients, but another set of miRNAs that showed differential expression between ASCs and CHB patients was also identified. Gene ontology and pathway enrichment analysis showed that the target genes of the identified miRNAs played a role in important biological functions, such as learning or memory, cell-cell adherens junction, ion channel inhibitor activity, TGF-beta signaling pathway, and p53 signaling pathway.

Conclusion

We identified some significant differentially expressed miRNA in different phases of HBV infection, which might serve as biomarkers or therapeutic targets in the future.

MiR-199a/b-5p inhibits hepatocellular carcinoma progression by post-transcriptionally suppressing ROCK1

In this study, we explored the actions of miR-199a/b-5p during hepatocellular carcinoma (HCC) progression and its potential target genes. Through heatmap miRNA expression analysis of 15 matched HCC tumor and adjacent non-tumor liver tissues from the TCGA database, we detected 19 mRNAs that were upregulated and 13 that were downregulated specifically in HCC. Among these, miR-199 family members were downregulated in HCC tumors and cell lines, as compared to controls. Low miR-199a/b-5p expression was also associated with poor overall survival of HCC patients. miR-199a/b-5p overexpression in HCC cell lines inhibited cell proliferation, migration and invasion, both in vitro and in vivo. In addition, miR199-a/b-5p post-transcriptionally suppressed Rho-associated coiled-coil kinase 1 (ROCK1). This in turn led to inhibition of ROCK1/MLC and PI3K/Akt signaling, which is necessary for HCC proliferation and metastasis. These results indicate that miR-199a/b acts as tumor suppressors in HCC and represent promising therapeutic targets.