RESUMO
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.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , RNA Longo não Codificante , Proteínas de Ligação a RNA , Humanos , Carcinogênese/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/patologia , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
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.
Assuntos
Catequina/análogos & derivados , Hepacivirus/fisiologia , Hepatite C/patologia , MicroRNAs/genética , Tetraspanina 28/genética , Regiões 3' não Traduzidas , Estudos de Casos e Controles , Catequina/farmacologia , Linhagem Celular , Simulação por Computador , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Hepatite C/genética , Hepatite C/metabolismo , Hepatite C/virologia , Humanos , Tetraspanina 28/metabolismo , Internalização do Vírus/efeitos dos fármacosRESUMO
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.
