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.

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.

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.

Progesterone suppresses interferon signaling by repressing TLR-7 and MxA expression in peripheral blood mononuclear cells of patients infected with hepatitis C virus.

This study aimed at investigating the effect of progesterone on interferon signaling pathways in peripheral blood mononuclear cells (PBMCs) of patients infected with hepatitis C virus (HCV). PBMCs were isolated from peripheral blood of 38 treatment-naïve HCV-infected patients, pooled, and stimulated with progesterone in the presence and absence of its receptor antagonist, mifepristone, along with interferon alpha (IFN-α) or imiquimod. Toll-like receptor (TLR) 7 and myxovirus resistance protein A (MxA) were quantified in PBMCs using RT-qPCR. Imiquimod alone or combined with progesterone did not change MxA expression in HCV-infected PBMCs. Progesterone decreased the inducing effect of IFN-α on TLR-7 expression in both males and females. Moreover, progesterone stimulation prior to IFN-α treatment attenuated the Jak/STAT pathway, which was reflected by decreased expression of MxA in females. Progesterone showed a negative impact on the IFN signaling pathway in HCV-infected PBMCs as it decreased the expression of TLR-7 in both genders, while MxA expression was decreased only in females.

Dual downregulation of microRNA 17-5p and E2F1 transcriptional factor in pediatric systemic lupus erythematosus patients.

The main objective of this study is to investigate the relative expression of miRNA 17-5p and one of its target genes E2F1 in the peripheral blood of systemic lupus erythematosus pediatric patients. The expression of miRNA 17-5p and its target E2F1 mRNA was analyzed by TaqMan real-time qPCR. Our results showed significant downregulation of miRNA 17-5p in SLE patients compared to healthy controls; moreover, miRNA 17-5p was more downregulated in patients on no treatment compared to those on treatment. Relative expression of E2F1, which is a target for miRNA 17-5p, was significantly downregulated as well on both mRNA and protein levels in SLE pediatric patients. In conclusion, our data show an unexpected dual downregulation of both miRNA 17-5p and its target gene E2F1 on the mRNA and protein levels. This may suggest an expression pattern of miRNA 17-5p and its target E2F1 that may be specific to SLE. [corrected].

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.

Development of a second version of the Cobas AmpliPrep/Cobas TaqMan hepatitis C virus quantitative test with improved genotype inclusivity.

Hepatitis C virus (HCV) RNA measurement has been facilitated by the introduction of real-time PCR-based assays with low limits of detection and broad dynamic ranges for quantification. In the present study, the performance of two second-version prototypes of the Cobas AmpliPrep/Cobas TaqMan HCV Quantitative Test (CAP/CTM v2) with decreased sample input volume and improved genotype inclusivity was investigated. A total of 232 serum and plasma samples derived from patients with chronic hepatitis C (genotype 1 [GT1], n = 108; GT2, n = 8; GT3, n = 24; GT4, n = 87; GT5, n = 3; and GT6, n = 2) were processed in parallel with the Cobas AmpliPrep/Cobas TaqMan HCV Test (CAP/CTM), Cobas Amplicor HCV Monitor Test v2.0 (CAM), and two second-version prototype formulations of CAP/CTM, Mastermix 1 (MMx1) and MMx2. In addition, three GT4 transcripts containing rare variant sequences were tested. The mean log(10) HCV RNA differences for the best-performing CAP/CTM v2/MMx2 formulation in comparison to CAM were -0.05, 0.05, -0.12, -0.10, -0.44, and -0.29 for patients with GT1, GT2, GT3, GT4, GT5, and GT6 infections, respectively. GT1, GT2, and GT4 samples including isolates with known variants within the 5' untranslated region (G145A, A165T) that were underquantified with CAP/CTM were correctly quantified with the second-version prototype. In addition, CAP/CTM v2 was able to accurately quantify the three transcripts with rare variant sequences. In conclusion, CAP/CTM v2 accurately quantifies HCV RNA across all HCV genotypes, including specimens with rare polymorphisms previously associated with underquantification.

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.

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.

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.

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.

Functional characterization of the human atrial essential myosin light chain (hALC-1) in a transgenic rat model.

Most patients with hypertrophic cardiomyopathy and congenital heart diseases express the atrial essential myosin light chains (ALC-1) in their ventricles, partially replacing the ventricular essential light chains (VLC-1). This VLC-1/ALC-1 isoform shift is correlated with an increase in cross-bridge cycling kinetics as measured using skinned fibers from the hypertrophied ventricles of human hearts. To study the functional importance of hALC-1 in the intact perfused heart, we generated a transgenic rat model (TGR) overexpressing hALC-1 in the heart. Twelve-week-old TGR rats expressed 17 +/- 4 microg hALC-1 per mg of whole SDS-soluble protein. Their perfused heart contractility parameters were evaluated using the Langendorff preparation. Expression of hALC-1 was accompanied by statistically significant improvements (P<0.001) in the contractile parameters of the hearts of the TGR compared to the age matched control (WKY) animals, represented by increases from 20.8 +/- 2.3 to 45.1 +/- 3.6 mmHg/g heart weight in the developed left ventricular pressure, 1,035.7 +/- 89.8 to 2,181 +/- 135.4 mmHg/s in the contraction rate, and 713 +/- 60.2 to 1,364 +/- 137.4 mmHg/s in the relaxation rate in the WKY and the TGR groups respectively. Characterizing the functional effects of hALC-1 at the whole organ level represents a step towards gene therapy of heart failure.

Human atrial myosin light chain 1 expression attenuates heart failure.

Most patients with hypertrophic cardiomyopathy and congenital heart diseases express the atrial essential myosin light chains (ALC-1) in their ventricles, replacing the ventricular essential light chains (VLC-1). VLC-1/ALC-1 isoform shift is correlated with increases in cardiac contractile parameters of a transgenic rat model overexpressing hALC-1 in the heart (TGR/hALC-1) compared to normal WKY rats. To investigate, whether the benefical effects of the hALC-1 on cardiac contractility could attenuate contractile failure of the overloaded heart, aortocaval shunt operations of 9-10 weeks old WKY and TGR/hALC-1 were performed. 5 weeks later, both animals groups were sacrificed for analysis of cardiac contraction and transgene expression. Control animals were operated but remained normal body and heart weights. The whole heart contractility parameters were evaluated using the Langendorff heart preparation. Shunt-operated TGR/hALC-1 and WKY rats developed comparable levels of cardiac hypertrophy which was associated with significant reduction of contractile parameters of the Langendorff hearts. However, the decline of cardiac contractility was less pronounced in shunt-operated TGR/hALC-1 compared to shunt-operated WKY. In fact, developed left ventricular pressure as well as maximal velocity of pressure development and relaxation were significantly higher in shunt-operated TGR/hALC-1 as compared to shunt-operated WKY. Expression of hALC-1 was 17 microg/mg whole SDS-protein in control (sham-operated) controls and declined significantly to 14 microg/mg whole SDS-protein in hypertrophied TGR/hALC-1. These results demonstrate that the expression of hALC-1 could have a beneficial effect on the overloaded hypertrophied heart.

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.

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.