Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0023890 (cirrhosis)
 42,195 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatitis C virus (HCV) is an oncogenic virus associated with the onset of hepatocellular carcinoma (HCC). The present study investigated the possible link between HCV infection and Netrin-1, a ligand for dependence receptors that sustains tumorigenesis, in particular in inflammation-associated tumors. We show that Netrin-1 expression is significantly elevated in HCV+ liver biopsies compared to hepatitis B virus (HBV+) and uninfected samples. Furthermore, Netrin-1 was upregulated in all histological stages of HCV+ hepatic lesions, from minimal liver fibrosis to cirrhosis and HCC, compared to histologically matched HCV- tissues. Both cirrhosis and HCV contributed to the induction of Netrin-1 expression, whereas anti-HCV treatment resulted in a reduction of Netrin-1 expression. In vitro, HCV increased the level and translation of Netrin-1 in a NS5A-La-related protein 1 (LARP1)-dependent fashion. Knockdown and forced expression experiments identified the receptor uncoordinated receptor-5 (UNC5A) as an antagonist of the Netrin-1 signal, though it did not affect the death of HCV-infected cells. Netrin-1 enhanced infectivity of HCV particles and promoted viral entry by increasing the activation and decreasing the recycling of the epidermal growth factor receptor (EGFR), a protein that is dysregulated in HCC. Netrin-1 and HCV are, therefore, reciprocal inducers in vitro and in patients, as seen from the increase in viral morphogenesis and viral entry, both phenomena converging toward an increase in the level of infectivity of HCV virions. This functional association involving a cancer-related virus and Netrin-1 argues for evaluating the implication of UNC5 receptor ligands in other oncogenic microbial species.
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PMID:Epidermal Growth Factor Receptor-Dependent Mutual Amplification between Netrin-1 and the Hepatitis C Virus. 2703 29

Hepatitis C virus (HCV) infection is a leading cause of hepatocellular carcinoma (HCC), mainly through cirrhosis induction, spurring research for a deeper understanding of HCV versus host interactions in cirrhosis. The present study investigated crosstalks between HCV infection and UNC5A, a netrin-1 dependence receptor that is inactivated in cancer. UNC5A and HCV parameters were monitored in patients samples (n=550) as well as in in vitro. In patients, UNC5A mRNA expression is significantly decreased in clinical HCV(+) specimens irrespective of the viral genotype, but not in (HBV)(+) liver biopsies, as compared to uninfected samples. UNC5A mRNA is downregulated in F2 (3-fold; P=0.009), in F3 (10-fold, P=0.0004) and more dramatically so in F4/cirrhosis (44-fold; P<0.0001) histological stages of HCV(+) hepatic lesions compared to histologically matched HCV(-) tissues. UNC5A transcript was found strongly downregulated in HCC samples (33-fold; P<0.0001) as compared with non-HCC samples. In vivo, association of UNC5A transcripts with polyribosomes is decreased by 50% in HCV(+) livers. Consistent results were obtained in vitro showing HCV-dependent depletion of UNC5A in HCV-infected hepatocyte-like cells and in primary human hepatocytes. Using luciferase reporter constructs, HCV cumulatively decreased UNC5A transcription from the UNC5 promoter and translation in a UNC5A 5'UTR-dependent manner. Proximity ligation assays, kinase assays, as well as knockdown and forced expression experiments identified UNC5A as capable of impeding autophagy and promoting HCV restriction through specific impact on virion infectivity, in a cell death-independent and DAPK-related manner. In conclusion, while the UNC5A dependence receptor counteracts HCV persistence through regulation of autophagy in a DAPK-dependent manner, it is dramatically decreased in all instances in HCC samples, and specifically by HCV in cirrhosis. Such data argue for the evaluation of the implication of UNC5A in liver carcinogenesis.
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PMID:Reciprocal antagonism between the netrin-1 receptor uncoordinated-phenotype-5A (UNC5A) and the hepatitis C virus. 2878 79