microRNA在乙型、丙型肝炎中的作用

近年来,作为基因表达的重要调节因子microRNA(miRNA),以及与这些miRNA关联或调控的各种肝脏疾病,如肝炎、肝纤维化和肝细胞癌(HCC)等方面的研究取得了新进展.许多编码miRNA的基因及其靶标被发现,它们与肝脏疾病的直接或间接的关联性也通过大量的实验研究(包括人体组织)得到确证.病毒性肝炎是由多种不同肝炎病毒引起的一组以肝脏损伤为主的传染病,根据病原学诊断,肝炎病毒至少有5种,但目前最常见的是HBV和HCV感染.本文就miRNA与病毒性肝炎的关系研究进展作一综述.     

miRNAs as Potential Biomarkers for Viral Hepatitis B and C

Around 257 million people are living with hepatitis B virus (HBV) chronic infection and 71 million with hepatitis C virus (HCV) chronic infection. Both HBV and HCV infections can lead to liver complications such as cirrhosis and hepatocellular carcinoma (HCC). To take care of these chronically infected patients, one strategy is to diagnose the early stage of fibrosis in order to treat them as soon as possible to decrease the risk of HCC development. microRNAs (or miRNAs) are small non-coding RNAs which regulate many cellular processes in metazoans. Their expressions were frequently modulated by up- or down-regulation during fibrosis progression. In the serum of patients with HBV chronic infection (CHB), miR-122 and miR-185 expressions are increased, while miR-29, -143, -21 and miR-223 expressions are decreased during fibrosis progression. In the serum of patients with HCV chronic infection (CHC), miR-143 and miR-223 expressions are increased, while miR-122 expression is decreased during fibrosis progression. This review aims to summarize current knowledge of principal miRNAs modulation involved in fibrosis progression during chronic hepatitis B/C infections. Furthermore, we also discuss the potential use of miRNAs as non-invasive biomarkers to diagnose fibrosis with the intention of prioritizing patients with advanced fibrosis for treatment and surveillance.     

HBV/HCV相关miRNAs研究进展

microRNAs（miRNAs）是一类由约22个核苷酸组成的非编码单链RNAs,通过抑制蛋白质翻译或降解mRNAs调节基因的表达。目前发现有2000多种人源miRNAs,参与调节发育、细胞增殖、凋亡以及压力反应过程中的基因表达等,而miRNAs基因突变或者异常表达可能会引发肿瘤等疾病。已有研究表明miRNAs在肝炎病毒（HBV、HCV等）感染以及肝癌的发生发展过程中,也发挥了重要的作用。本文主要就HBV/HCV调控宿主miRNAs,以及miRNAs如何影响病毒的复制等方面进行阐述。     

Hepatocellular carcinoma,hepatitis C virus infection and miRNA involvement: Perspectives for new therapeutic approaches

Chronic hepatitis C virus (HCV) infection is the principal etiology of cirrhosis and, ultimately, hepatocellular carcinoma (HCC). At present, approximately 71 million people are chronically infected with HCV, and 10%–20% of these are expected to develop severe liver complications throughout their lifetime. Scientific evidence has clearly shown the causal association between miRNAs, HCV infection and HCC. Although it is not completely clear whether miRNA dysregulation in HCC is the cause or the consequence of its development, variations in miRNA patterns have been described in different liver diseases, including HCC. Many studies have analyzed the importance of circulating miRNAs and their effect on cell proliferation and apoptosis. In this Review, we aim to summarize current knowledge on the association between miRNA, HCV and HCC from a diagnostic point of view, and also the potential implications for therapeutic approaches.     

Molecular mechanisms of viral hepatitis induced hepatocellular carcinoma

Chronic infection with viral hepatitis affects half a billion individuals worldwide and can lead to cirrhosis, cancer, and liver failure. Liver cancer is the third leading cause of cancer-associated mortality, of which hepatocellular carcinoma (HCC)represents 90%of all primary liver cancers. Solid tumors like HCC are complex and have heterogeneous tumor genomic profiles contributing to complexity in diagnosis and management. Chronic infection with hepatitis B virus (HBV),hepatitis delta virus (HDV), and hepatitis C virus (HCV) are the greatest etiological risk factors for HCC. Due to the significant role of chronic viral infection in HCC development, it is important to investigate direct (viral associated) and indirect (immune-associated) mechanisms involved in the pathogenesis of HCC. Common mechanisms used by HBV, HCV, and HDV that drive hepatocarcinogenesis include persistent liver inflammation with an impaired antiviral immune response, immune and viral protein-mediated oxidative stress, and deregulation of cellular signaling pathways by viral proteins.DNA integration to promote genome instability is a feature of HBV infection, and metabolic reprogramming leading to steatosis is driven by HCV infection. The current review aims to provide a brief overview of HBV, HCV and HDV molecular biology, and highlight specific viral-associated oncogenic mechanisms and common molecular pathways deregulated in HCC, and current as well as emerging treatments for HCC.     

MicroRNAs as therapeutic strategy for hepatitis B virus-associated hepatocellular carcinoma: Current status and future prospects

Hepatocellular carcinoma (HCC) remains to be one of the top causing cancer-related deaths today. The majority of HCC cases are reported to be the result of chronic hepatitis B virus (HBV) infection. Current treatments for HBV-related HCC revolve around the use of drugs to inhibit viral replication, as a high level of viral load and antigen in circulation often presents a poor patient prognosis. However, existing therapies are inefficient in the complete eradication of HBV, often resulting in tumour recurrence. The involvement of microRNAs (miRNAs) in important processes in HBV-related HCC makes it an important player in the progression of HCC in chronic hepatitis B infected patients. In this review, we discuss the key aspects of HBV infection and the important viral products that may regulate cancer-related processes via their interaction with miRNAs or their closely related protein machinery. Conversely, we also look at how miRNAs may go about regulating the virus, especially in vital processes like viral replication. Apart from miRNAs acting as either oncogenes or tumour-suppressors, we also look at how miRNAs may function as biomarkers that may possibly serve as better candidates than those currently employed in the diagnosis of HBV infection or HBV-related HCC. A summary of the roles of miRNAs in HBV-related HCC will hopefully lead to a gain in understanding of the pathogenesis process and pave the way for new insights in medical therapy.     

microRNA: A Promising Diagnostic Biomarker and Therapeutic Target for Hepatocellular Carcinoma

microRNAs constitute a novel class of small, non-coding RNAs that negatively regulate gene expression via translational inhibition or mRNA degradation. Aberrant miRNA expression has been implicated in the initiation, progression, and metastasis of hepatocellular carcinoma (HCC). It is well-documented that miRNAs function as either tumor suppressor genes or oncogenes in the development and progression of HCC. Additionally, substantial evidence suggests that unique miRNA signatures can serve as valuable diagnostic and prognostic biomarkers for HCC. Interestingly, certain subsets of miRNAs have also been identified as potential therapeutic targets for HCC.     

Do hepatitis B virus and hepatitis C virus co‐infections increase hepatocellular carcinoma occurrence through synergistically modulating lipogenic gene expression?

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections cause a wide range of liver diseases including hepatocellular carcinoma (HCC). Because of the similar modes of transmission, HBV HCV co-infections are found in approximately 7-20 million people globally. Compared with HBV or HCV mono-infections, co-infections are associated with more severe liver diseases and higher risk of HCC. Abnormal lipid biosynthesis and metabolism has been increasingly recognized as a cause for cancer. While HBV infection does not seem to significantly increase the risk of developing hepatic steatosis, steatosis is a prominent feature of chronic hepatitis C (CHC). In addition, steatosis in HBV or HCV mono-infections is a significant and independent risk factor for HCC. However, whether and how HBV HCV co-infections synergistically increase the risk of HCC development through modulating lipid metabolism is not well understood. Possible mechanisms by which steatosis causes HCC include: activation of sterol regulatory element-binding protein-mediated lipogenesis through the PI3K-Akt pathway, abnormal activation of peroxisome proliferator-activated receptors and endoplasmic reticulum stress. Here, we review the potential mechanisms by which HBV HCV co-infections may increase HCC risk through modulation of lipogenic gene expression. We begin with reviewing the impact of HBV and HCV on host lipogenic gene expression and carcinogenesis. We then discuss the potential mechanisms by which HBV and HCV can increase carcinogenesis through synergistically activating lipid biosynthesis and metabolism. We end by sharing our thoughts on future research directions in this emerging paradigm with an ultimate goal of developing effective therapeutics.     

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.     

MicroRNA silencing of tumor suppressor DLC-1 promotes efficient hepatitis C virus replication in primary human hepatocytes

MicroRNAs (miRNAs) are approximately 22-nucleotide noncoding RNAs that constitute silencers of target gene expression. Aberrant expression of miRNA has been linked to a variety of cancers, including hepatocellular carcinoma (HCC). Hepatitis C virus (HCV) infection is considered a major cause of chronic liver disease and HCC, although the mechanism of virus infection-associated hepatocarcinogenesis remains unclear. We report a direct role of miRNAs induced in HCV-infected primary human hepatocytes that target the tumor suppressor gene DLC-1 (a Rho GTPase-activating protein), which is frequently deleted in HCC, and other solid human tumors. MicroRNA miR-141 that targets DLC-1 was accentuated in cells infected with HCV genotypes 1a, 1b, and 2a. We present several lines of evidence that efficient HCV replication requires miR-141-mediated suppression of DLC-1. An increase in miR-141 correlated with the inhibition of DLC-1 protein in HCV-infected cells. Depletion of miR-141 with oligonucleotides complementary to the miRNAs inhibited virus replication, whereas artificially increased levels of intracellular miR-141 enhanced HCV replication. HCV-infected hepatocytes showed enhanced cell proliferation that can be countered by overexpression of DLC-1. CONCLUSION: The collective results of this study suggest a novel mechanism of HCV infection-associated miRNA-mediated regulation of a tumor suppressor protein that has the ability to influence cell proliferation and HCV infection-mediated liver cancer.     

Evaluation of metabolic factors on the prognosis of patients undergoing resection of hepatocellular carcinoma

Background and Aim: The metabolic factors including obesity, diabetes, and hypertension have been implicated as risk factors of hepatocellular carcinoma (HCC) in patients with chronic hepatitis. The effects of metabolic factors were investigated on the prognosis of patients undergoing resection of HCC. Methods: A total of 469 HCC patients were classified into three groups; hepatitis B virus (HBV)‐, hepatitis C virus (HCV)‐, and non‐HBV/HCV (NBC)‐related HCC. Further, the patients with HCV‐related HCC were sub‐classified into three groups; the patients who did not have documented hypertension, hypertensive patients who received angiotensin II‐blocking agents (ABA), and hypertensive patients who received no ABA. Results: There were no significant difference of survival in the HBV‐HCC and NBC‐HCC patients with or without obesity, diabetes, and hypertension. In the patients with HCV‐related HCC, however, hypertensive patients were significantly worse on both disease‐free and overall survivals than non‐hypertensive patients. Among the HCV‐HCC patients with chronic hepatitis, hypertensive patients with ABA had significantly better preoperative liver function, and hypertensive patients without ABA were significantly worse on both disease‐free and overall survivals than those of hypertensive patients with ABA and non‐hypertensive patients. Conclusions: Results suggest that hypertension is a risk factor for a poor prognosis after resection of HCV‐related HCC. Angiotensin II blockade may improve the prognosis of hypertensive patients with early hepatic fibrosis after resection in HCV‐related HCC.     

role of microRNAs in the main molecular pathways of hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is the most common primary liver malignant neoplasia. HCC is characterized by a poor prognosis. The need to find new molecular markers for its diagnosis and prognosis has led to a progressive increase in the number of scientific studies on this topic. MicroRNAs(miRNAs) are small noncoding RNA that play a role in almost all main cellular pathways. miRNAs are involved in the regulation of expression of the major tumor-related genes in carcinogenesis, acting as oncogenes or tumor suppressor genes. The aim of this review was to identify papers published in 2017 investigating the role of miRNAs in HCC tumorigenesis. miRNAs were classified according to their role in the main molecular pathways involved in HCC tumorigenesis:(1) m TOR;(2) Wnt;(3) JAK/STAT;(4) apoptosis; and(5) MAPK. The role of miRNAs in prognosis/response prediction was taken into consideration. Bearing in mind that the analysis of miRNAs in serum and other body fluids would be crucial for clinical management, the role of circulating miRNAs in HCC patients was also investigated. The most represented mi RNA-regulated pathway in HCC is m TOR, but apoptosis, Wnt, JAK/STAT or MAPK pathways are also influenced by mi RNA expression levels. These miRNAs could thus be used in clinical practice as diagnostic, prognostic or therapeutic targets for HCC treatment.