Regulation of IGF2BP1 by miR-186 and its impact on downstream lncRNAs H19, FOXD2-AS1, and SNHG3 in HCC.

AIM: We have previously characterized oncogenic properties of IGF2BP1 in HCC, and its regulation by short noncoding RNAs (ncRNAs). Recent evidence suggests that IGF2BP1 itself may regulate long ncRNAs (lncRNAs). Therefore, this study aimed at exploring the interplay between IGF2BP1 and various upstream and downstream ncRNAs and its link to HCC pathogenesis. MATERIALS AND METHODS: Bioinformatic analysis was used to identify up- and downstream ncRNAs interacting with IGF2BP1. Huh-7 cells were transfected with siRNAs against IGF2BP1 and microRNA mimics. Relative gene expression was determined using RTqPCR and IGF2BP1 protein was quantified by western blot. Luciferase binding assay was used to explore the targeting of IGF2BP1 3'UTR. HCC tumorigenesis was measured by MTT assay, BrdU-incorporation assay, colony-forming assay, and scratch assay. KEY FINDINGS: Bioinformatic analysis identified three oncogenic lncRNAs - namely H19, FOXD2-AS1, and SNHG3 - potentially regulated by IGF2BP1. Knockdown of IGF2BP1 decreased the expression of all three oncogenic lncRNAs and inhibited malignant cell behaviors. miR-186 was revealed as a possible upstream regulator of IGF2BP1. miR-186 mimics decreased IGF2BP1 mRNA and protein levels. miR-186 was significantly lower while IGF2BP1 was elevated in cancerous tissues from ten HCC patients compared to five healthy controls. In addition, miR-186 mimics caused a downregulation of the oncogenic lncRNAs H19, SNHG3, and FOXD2-AS1 and a concomitant decrease in cell viability, proliferation, migration, and clonogenicity. SIGNIFICANCE: miR-186 may exert tumor suppressor effects in HCC by repressing oncogenic lncRNAs H19, SNHG3, and FOXD2-AS1 through its effect on IGF2BP1.

Competing Endogenous RNAs in Hepatocellular Carcinoma-The Pinnacle of Rivalry.

The role of noncoding transcripts in gene expression is nowadays acknowledged to keep various diseases at bay-despite being referred to as "junk" DNA several years ago. Believed to be at the heart of multiple regulatory pathways, microRNAs (miRNAs) are small noncoding RNAs (ncRNAs) involved in posttranscriptional gene regulation. Recently, the discovery of ncRNAs that compete for shared miRNA pools has dimmed the light on the solo performance of miRNAs in genomic regulation. Indeed, several studies describe RNAs such as long noncoding RNAs, mRNAs, circular RNAs, pseudogenes, and viral RNAs as competing endogenous RNAs (ceRNAs) that sequester miRNAs, allowing for de-repression of downstream miRNA targets. Such integration between coding and noncoding transcripts forms complex ceRNA networks that when dysregulated lead to several diseases such as hepatocellular carcinoma. Here, the authors review perturbed ceRNA networks in hepatocellular carcinoma, describe the role of each in tumorigenesis, and discuss their various clinical implications.

Epigallocatechin gallate (EGCG) and miR-548m reduce HCV entry through repression of CD81 receptor in HCV cell models.

Epigallocatechin gallate (EGCG) is the most abundant component in green tea extract, that has powerful antioxidant and antiviral effects. It has been previously reported to inhibit HCV entry via several mechanisms. Hence, this study aimed at further investigating the potential impact of EGCG on HCV entry through regulation of the expression of tetraspanin receptor CD81 by the novel predicted miR-548m. Liver biopsies were obtained from 29 HCV patients and 10 healthy controls for expression profiling. Huh7 cells were stimulated with EGCG and subsequently miR-548m expression was assessed. Naïve, HCV- ED43/JFH-1 and HCV-JFH-1 infected Huh7 cells were transfected by miR-548m mimics and inhibitors. Consequently, CD81 protein and mRNA levels were assessed using flow cytometry and qRT-PCR, respectively. Additionally, these cells were used to investigate HCV permissiveness into Huh7 cells using qRT-PCR for viral quantification. Direct binding confirmation of miR-548m to CD81 was done using luciferase reporter assay. In-silico analysis revealed miR-548m to have two potential binding sites in the 3'UTR of CD81 mRNA. EGCG boosted miR-548m expression in Huh7 cells. Additionally, miR-548m caused a downregulation of CD81 protein and mRNA levels as well as reduction in HCV infectivity of Huh7 cells. Luciferase binding assay confirmed the binding of miR-548m to CD81 mRNA at the two predicted binding sites. Intriguingly, miR-548m expression was not detected in healthy liver biopsies but was found in liver biopsies of HCV patients. This study shows that EGCG might act as an anti-HCV agent that reduces cellular infectivity via enhancing miR-548m expression and repressing CD81 receptor.

Correction to: Ectopic delivery of miR-200c diminishes hepatitis C virus infectivity through transcriptional and translational repression of Occludin.

The author would like to correct the errors in the online published article.

MiR-615-5p depresses natural killer cells cytotoxicity through repressing IGF-1R in hepatocellular carcinoma patients.

miR-615-5p was characterized by our group as a tumour suppressor. IGF-1 R activates a downstream signalling pathway, well characterized in liver cells, however, its role in immunity especially Natural Killer cells (NKs) remains vague. This study aimed at investigating the regulatory role of miR-615-5p on IGF signalling and its impact on NKs cytotoxicity in HCC. Our results showed an upregulation in miR-615-5p and IGF-1 R in NKs of 130 HCC patients compared to 35 controls. Forcing the expression of miR-615-5p, repressed IGF-IR, attenuated NKs cytotoxicity, decreased CD56dim, increased CD56bright NK subsets and reduced the cytotoxic markers NKG2D, TNF-α and perforins. It repressed NKG2D ligand (ULBP2) in Huh-7 cells. In conclusion, miR-615-5p represses IGF-1 R in NKs and their target hepatocytes; however, it has a contradicting impact on HCC progression on both cell types. These findings might pave the way for better understanding the role of microRNAs in NKs function and HCC immune-pathogenesis.

Ectopic delivery of miR-200c diminishes hepatitis C virus infectivity through transcriptional and translational repression of Occludin.

Occludin (OCLN) is an essential factor for HCV entry through interacting with other surface receptors. The aim of this study was to investigate the epigenetic regulation of Occludin expression and to study its impact on viral infectivity. microRNAs expression was assessed using qRT-PCR, while OCLN protein expression was investigated by indirect immunofluorescence and Western blotting. Viral infectivity was assessed by measuring viral-load using qRT-PCR. In silico analysis predicted that miR-200c targeted the OCLN 3'UTR, which was further experimentally confirmed. miR-122 was previously validated to target the 3'UTR of OCLN and was used as a control. We report a significant down-regulation of miR-200c in liver tissues of HCV-infected patients. Ectopic expression of both miR-122 and miR-200c in Huh7 cells reduced OCLN mRNA and protein levels. Viral infectivity was significantly reduced by miR-200c but enhanced by miR-122. This work sheds light on miR-200c as a novel regulator of HCV infectivity through the regulation of OCLN.

MicroRNA-486-5p enhances hepatocellular carcinoma tumor suppression through repression of IGF-1R and its downstream mTOR, STAT3 and c-Myc.

The insulin-like growth factor (IGF)-axis has been paradigmatically involved in hepatocellular carcinoma (HCC) tumor initiation, progression and drug resistance. Consequently, members of the IGF-axis and most importantly, IGF-1 receptor (IGF-1R) have been considered as intriguing targets for HCC therapy. Few miRNAs have been recently reported to be associated with IGF-1R regulation. The present study aimed to investigate the role of microRNA (miRNA/miR)-486-5p in the regulation of IGF-1R and its downstream signaling cascades. miR-486-5p was markedly downregulated in hepatitis C virus-induced HCC tissues and Huh-7 cells. Forcing the expression of miR-486-5p in Huh-7 cells resulted in the repression of IGF-1R, mammalian target of rapamycin (mTOR), signal transducer and activator of transcription 3 (STAT3) and c-Myc mRNA levels. Ectopic expression of miR-486-5p in Huh-7 cells markedly repressed cellular viability, proliferation, migration and clonogenicity in a similar pattern to IGF-1R small interfering RNAs, and were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, BrdU incorporation, wound healing and colony forming assays, respectively. Overall, the study findings demonstrated that miR-486-5p acts as a tumor suppressor in HCC through the repression of essential members of the IGF-axis, including IGF-1R and its downstream mediators mTOR, STAT3 and c-Myc.

Interplay between microRNA-17-5p, insulin-like growth factor-II through binding protein-3 in hepatocellular carcinoma.

AIM: To investigate the effect of microRNA on insulin-like growth factor binding protein-3 (IGFBP-3) and hence on insulin-like growth factor-II (IGF-II) bioavailability in hepatocellular carcinoma (HCC). METHODS: Bioinformatic analysis was performed using microrna.org, DIANA lab and Segal lab softwares. Total RNA was extracted from 23 HCC and 10 healthy liver tissues using mirVana miRNA Isolation Kit. microRNA-17-5p (miR-17-5p) expression was mimicked and antagonized in HuH-7 cell lines using HiPerFect Transfection Reagent, then total RNA was extracted using Biozol reagent then reverse transcribed into cDNA followed by quantification of miR-17-5p and IGFBP-3 expression using TaqMan real-time quantitative PCR. Luciferase reporter assay was performed to validate the binding of miR-17-5p to the 3'UTR of IGFBP-3. Free IGF-II protein was measured in transfected HuH-7 cells using IGF-II ELISA kit. RESULTS: Bioinformatic analysis revealed IGFBP-3 as a potential target for miR-17-5p. Screening of miR-17-5p and IGFBP-3 revealed a moderate negative correlation in HCC patients, where miR-17-5p was extensively underexpressed in HCC tissues (P = 0.0012), while IGFBP-3 showed significant upregulation in the same set of patients (P = 0.0041) compared to healthy donors. Forcing miR-17-5p expression in HuH-7 cell lines showed a significant downregulation of IGFBP-3 mRNA expression (P = 0.0267) and a significant increase in free IGF-II protein (P = 0.0339) compared to mock untransfected cells using unpaired t-test. Luciferase assay validated IGFBP-3 as a direct target of miR-17-5p; luciferase activity was inhibited by 27.5% in cells co-transfected with miR-17-5p mimics and the construct harboring the wild-type binding region 2 of IGFBP-3 compared to cells transfected with this construct alone (P = 0.0474). CONCLUSION: These data suggest that regulating IGF-II bioavailability and hence HCC progression can be achieved through targeting IGFBP-3 via manipulating the expression of miRNAs.

Contradicting interplay between insulin-like growth factor-1 and miR-486-5p in primary NK cells and hepatoma cell lines with a contemporary inhibitory impact on HCC tumor progression.

In this study, an impaired natural killer (NK) cell cytolytic activity in 135 hepatocellular carcinoma (HCC) patients parallel to a reduced expression level of insulin-like growth factor (IGF)-1 in NK cells of HCC patients has been revealed. Ectopic expression of miR-486-5p, a direct upstream regulator of IGF-1, restored the endogenous level of IGF-1 in NK cells of HCC patients, thus augmenting its cytolytic activity against Huh7 cells in an opposite manner to the IGF-1 siRNAs. Unorthodoxly, over-expression of miR-486-5p in target hepatocytes resulted in the repression of IGF-1, suppression of Huh7 cells proliferation and viability in a similar pattern to the IGF-1 siRNAs. Therefore, this study highlights a potential role of IGF-1 in modulating cytolytic potential of NK cells of HCC patients. miR-486-5p acts in a cell-specific manner, differentially modulating IGF-1 expression in NK cells and their target hepatocytes with a contemporary inhibitory impact on HCC progression.

Abrogating the interplay between IGF2BP1, 2 and 3 and IGF1R by let-7i arrests hepatocellular carcinoma growth.

IGF2BP 1, 2 and 3 control the fate of many transcripts. Immunoprecipitation studies demonstrated the IGF2BPs to bind to IGF1R mRNA, and our laboratory has recently shown them to post-transcriptionally regulate IGF1R. This study sought to identify a microRNA regulating the IGF2BPs and consequently IGF1R. All three IGF2BPs were among the top-ranked predicted targets of let-7i. Let-7i was downregulated in HCC tissues, and transfection of HuH-7 with let-7i inhibited malignant cell behaviors and decreased IGF2BPs transcripts. Direct binding of let-7i to IGF2BP2 and IGF2BP3 3'UTRs was confirmed, and the effect of let-7i caused a decrease in the IGF2BPs' target gene, the IGF1R. IGF1R mRNA was inversely correlated with let-7i in HCC tissues and was reduced upon let-7i transfection into HuH-7. Reporter assays validated IGF1R as a target of let-7i. Therefore, let-7i may control HCC tumorigenesis by regulating IGF1R directly and indirectly by interrupting the interplay between IGF1R and the IGF2BPs.

Epigenetic regulation of insulin-like growth factor axis in hepatocellular carcinoma.

The insulin-like growth factor (IGF) signaling pathway is an important pathway in the process of hepatocarcinogenesis, and the IGF network is clearly dysregulated in many cancers and developmental abnormalities. In hepatocellular carcinoma (HCC), only a minority of patients are eligible for curative treatments, such as tumor resection or liver transplant. Unfortunately, there is a high recurrence of HCC after surgical tumor removal. Recent research efforts have focused on targeting IGF axis members in an attempt to find therapeutic options for many health problems. In this review, we shed lights on the regulation of members of the IGF axis, mainly by microRNAs in HCC. MicroRNAs in HCC attempt to halt the aberrant expression of the IGF network, and a single microRNA can have multiple downstream targets in one or more signaling pathways. Targeting microRNAs is a relatively new approach for identifying an efficient radical cure for HCC.

miR-29a Promotes Lipid Droplet and Triglyceride Formation in HCV Infection by Inducing Expression of SREBP-1c and CAV1.

Aims: To examine the regulation of SREBP-1c and CAV1 by microRNA-29a (miR-29a) in cells infected with hepatitis C virus (HCV) in an attempt to control HCV-induced non-alcoholic fatty liver disease. Methods: In order to examine the manipulation of SREBP-1c and CAV1 by miR-29a, oleic acid (OA)-treated JFH-I-infected Huh-7 cells were used. OA was added 24 h post-transfection and gene expression was investigated by qRT-PCR at 48 h post treatment. The functional impact of the observed alteration in SREBP-1c and CAV1 expression was analyzed by examining lipid droplet (LD) and triglyceride (TG) content at 72 h post-OA treatment using light microscopy and spectrophotometry, respectively. Viral load was quantified by qRT-PCR at 72 h post-transfection. Results: OA treatment induced the expression of miR-29a and SREBP-1c, as compared to untreated cells. Forced miR-29a expression led to a significant up-regulation of SREBP-1c as well as CAV1 compared to mock untransfected cells. Ectopic expression of miR-29a resulted in a marked increase in LDs and their respective TGs, while miR-29a antagomirs decreased both the LD and TG content compared to mock untransfected cells. Moreover, forcing the expression of miR-29a in JFH-1 HCV-infected Huh-7 cells resulted in 53% reduction in viral titers compared to mock untransfected Huh-7 cells. Conclusion: Inducing miR-29a expression significantly induces SREBP-1c and CAV1 expression, thereby increasing LDs as well as their respective TGs. Nonetheless, forcing the expression of miR-29a resulted in reduction of HCV RNA levels in Huh-7 cells.

miR-34a: Multiple Opposing Targets and One Destiny in Hepatocellular Carcinoma.

Background and Aims: The role of miR-34a in hepatocellular carcinoma (HCC) is controversial and several unresolved issues remain, including its expression pattern and relevance to tumor etiology, tumor stage and prognosis, and finally, its impact on apoptosis. Methods: miR-34a expression was assessed in hepatitis C virus (HCV)-induced non-metastatic HCC tissues by RT-Q-PCR. Huh-7 cells were transfected with miR-34a mimics and the impact of miR-34a was examined on 84 pro-apoptotic/anti-apoptotic genes using PCR array; its net effect was tested on cell viability via MTT assay. Results: miR-34a expression was up-regulated in HCC tissues. Moreover, miR-34a induced a large set of pro-apoptotic/anti-apoptotic genes, with a net result of triggering apoptosis and repressing cell viability. Conclusions: HCC-related differential expression of miR-34a could be etiology-based or stage-specific, and low expression of miR-34a may predict poor prognosis. This study's findings also emphasize the role of miR-34a in apoptosis.

Repressing PU.1 by miR-29a∗ in NK cells of HCV patients, diminishes its cytolytic effect on HCV infected cell models.

OBJECTIVES: Natural killer cells are immune safeguards against HCV infection. PU.1 is a pivotal transcription factor in the development of NK cells. This study aimed at studying the regulatory effect of miRNAs on both development and function of NK cells isolated from HCV patients. METHODS: NK cells were isolated from 17 chronic HCV patients and 12 healthy controls; after which miRNA and mRNA were quantified using qRT-PCR. Manipulating miRNA expression using mimics and antagomirs, was performed followed by investigating downstream targets as well as viral abundance. RESULTS: PU.1 expression levels were upregulated in NK cells of HCV patients. In silico analysis revealed PU.1 to be a potential downstream target of miR-29a(∗), where miR-29a(∗) overexpression in NK cells caused a significant downregulation in PU.1 mRNA. Forcing miR-29a(∗) caused a downregulation of the cytotoxicity determinant NK activating receptor (NKG2D) via upregulation of miR-155. Moreover, perforin-1 mRNA was found to be downregulated upon forcing the expression of miR-29a(∗) in NK cells of HCV patients. This decrease in NK cytolytic function was accompanied by an 80% viral load increase in cocultured HCVcc cell models. CONCLUSIONS: This study showed that HCV infection might abrogate NK cytotoxic potential through altering PU.1, NKG2D receptor and perforin molecules.

miR-1275: A single microRNA that targets the three IGF2-mRNA-binding proteins hindering tumor growth in hepatocellular carcinoma.

This study aimed to identify a single miRNA or miR (microRNA) which regulates the three insulin-like growth factor-2-mRNA-binding proteins (IGF2BP1, 2 and 3). Bioinformatics predicted miR-1275 to simultaneously target the three IGF2BPs, and screening revealed miR-1275 to be underexpressed in hepatocellular carcinoma (HCC) tissues. Transfection of HuH-7 cells with miR-1275 suppressed IGF2BPs expression and all three IGF2BPs were confirmed as targets of miR-1275. Ectopic expression of miR-1275 and knockdown of IGF2BPs inhibited malignant cell behaviors, and also reduced IGF1R protein and mRNA. Finally IGF1R was validated as a direct target of miR-1275. These findings indicate that the tumor-suppressor miR-1275 can control HCC tumor growth partially through simultaneously regulating the oncogenic IGF2BPs and IGF1R.

Targeting E2F1 and c-Myc expression by microRNA-17-5p represses interferon-stimulated gene MxA in peripheral blood mononuclear cells of pediatric systemic lupus erythematosus patients.

OBJECTIVES: Elevated type I interferon (IFN) is believed to be one of the crucial factors involved in the pathogenesis of systemic lupus erythematosus (SLE). Its expression was recently found to be governed by the transcription factor E2F1 which is involved in an autoregulatory triad along with c-Myc and the microRNA polycistron miR-17-92. However, this intricate triad has seldom been investigated in SLE patients. Therefore, the current study was undertaken to investigate the expression pattern of the E2F1/c-Myc/miR-17-5p triad in peripheral blood of SLE patients as well as to examine the impact of manipulating this triad using miR-17-5p mimics and inhibitors on IFN signature in SLE patients. METHODS: Expression of the E2F1/c-Myc/miR-17-5p triad and the IFN-stimulated gene MxA was analyzed using real time qPCR. Peripheral blood mononuclear cells from SLE patients and controls were transfected with miR-17-5p mimics and antagomirs using the HiPerfect transfection reagent. RESULTS: E2F1 transcripts and miR-17-5p were significantly downregulated while c-Myc and MxA transcripts were significantly upregulated in SLE. Also, transfection of SLE PBMCs with miR-17-5p mimics led to a substantial repression of E2F1 and c-Myc expression. The overall change in this triad upon miR-17-5p mimicking resulted in lowering the transcript levels of the IFN-inducible gene MxA in SLE. CONCLUSION: This may advocate the manipulation/use of the E2F1/c-Myc/miR-17-5p trinity to effectively control the aberrantly high levels of type I IFN activity in lupus patients.

A pleiotropic effect of the single clustered hepatic metastamiRs miR-96-5p and miR-182-5p on insulin-like growth factor II, insulin-like growth factor-1 receptor and insulin-like growth factor-binding protein-3 in hepatocellular carcinoma.

MicroRNAs (miRs) have a major role in the pathogenesis of hepatocellular carcinoma (HCC). As the insulin-like growth factor (IGF) axis is a highly tumorigenic pathway in HCC, the present study attempted to target it with miRs. Potential targeting of crucial members of the IGF axis by miRNAs at the 3'-untranslated region (3'-UTR) was predicted using bioinformatic tools, such as microrna.org, Diana lab and Targetscan, while 5'-UTR targeting was predicted using bibiserv software. Expression profiling of obtained miRNAs was performed using quantitative polymerase chain reaction (qPCR) in 22 non-metastatic HCC biopsy samples and 10 healthy tissues. To investigate the impact of miRNAs on their potential downstream targets, transfection of miRNAs was performed in HuH-7 cells and the targets' expression was quantified using qPCR. Transcripts of insulin-like growth factor-1 receptor (IGF-1R), insulin-like growth factor binding protein-3 (IGFBP-3) and IGF-II were found to be potentially targeted at the 5'-UTR and 3'-UTR regions by the single clustered hepatic metastamiRs miR-96-5p and miR-182-5p. The two miRNAs showed a similar expression pattern in HCC tissues compared to those in healthy tissues. Forced expression of miR-96-5p and miR-182-5p in the HCC cell line HuH-7 had inducing effects on IGFBP-3 and IGF-II transcripts. Of note, the two miRs had differential effects on IGF-1R, where miR-96-5p induced IGF-1R mRNA expression and miR-182-5p inhibited its expression. The present study revealed the pleiotropic impact of the single clustered hepatic metastamiRs miR-96-5p and miR-182-5p on IGF-1R, and an inducing effect on IGF-II and IGFBP-3 in hepatocellular carcinoma.

Expression signature of microRNA-155 in hepatitis C virus genotype 4 infection.

Hepatits C virus (HCV) genotype 4 (GT4) shows low treatment response rates and discrepancies when compared to other genotypes. However, the reason underlying these discrepancies remains unclear due to the limited number of studies on GT4. microRNA-155 (miR-155) is a noteworthy example of a discrepancy in GT4, as it was found to be upregulated in genotypes 1, 2 and 3 HCV infection, but downregulated in GT4-HCV-infected peripheral blood mononuclear cells (PBMCs). The present study aimed to investigate the expression of miR-155 in PBMCs, serum and liver tissues of GT4-HCV-infected patients. miR-155 expression was assessed using reverse transcription-quantitative polymerase chain reaction in GT4-HCV-infected PBMCs, serum and liver tissues, as well as GT2- and GT4-infected Huh7 cells, and compared to the healthy controls. There was no difference in miR-155 expression observed between naïve GT4-HCV patients and healthy controls in the PBMCs and serum. In HCV-infected liver tissues, however, a significant downregulation was observed. The unique miR-155 expression pattern during GT4 infection was confirmed in the infected Huh7 cell lines when compared to GT2 infection. Clinical data showed a positive correlation between liver transaminases and serum miR-155 expression. In addition, serum miR-155 expression was significantly lower in naïve non-responders (NRs) than naïve sustained virological responders (SVRs), and in post-treatment NRs compared to post-treatment SVRs. In conclusion, miR-155 was not only proven to be a genotype-specific microRNA that is not induced during GT4-HCV infection, but also a good prognostic factor and predictor of response to treatment enabling a non-invasive differentiation between NRs and SVRs during GT4-HCV infection.

Mir-194 is a hepatocyte gate keeper hindering HCV entry through targeting CD81 receptor.

OBJECTIVE: The tetraspanin CD81 is one of the main receptors involved in hepatitis C virus entry. Herein, we aimed to explore the role of microRNAs in regulating CD81 receptor expression and function. PATIENTS AND METHODS: Bioinformatics analysis was carried out to select potential mircroRNAs that binds CD81 3'untranslated region. Liver biopsies taken from 28 HCV genotype- 4 patients and 10 healthy donors were screened. Naïve, JFH1 and ED43/JFH1- infected- Huh7 cells were transfected with mimics and inhibitors followed by analyzing CD81 protein and mRNA expression. This was done using flow cytometry and Q-RT PCR, respectively. HCV entry into Huh7 cells was investigated post-transfection. Binding confirmation was done using luciferase reporter vector harboring wild/mutant target sites of microRNA. The impact of Epigallocatechin-gallate on modulating microRNA/CD81 expression was assessed. RESULTS: Bioinformatics revealed that CD81 is a potential down-stream target for miR-194. A significant inverse correlation was found between miR-194 and CD81 expression in liver biopsies of HCV patients. Forcing the expression of miR-194 showed a down-regulation of CD81 protein, mRNA expression and significantly abrogated the HCV infectivity of Huh7 cells. Stimulation with EGCG enhanced mir-194 expression and down-regulated CD81 expression. CONCLUSION: This study showed that mir-194 hinders HCV entry through targeting CD81 receptors.

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.