Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019204 (hepatocellular carcinoma)
 71,386 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The intrinsic oncolytic specificity of vesicular stomatitis virus (VSV) is currently being exploited to develop alternative therapeutic strategies for hepatocellular carcinoma (HCC). We have observed earlier that, in contrast to cultured human HCC cells, primary human hepatocytes (PHHs) are refractory to VSV infection. Impairment of the type I interferon (IFN) pathway in HCC cells has been suggested to be the mechanism by which these cells become susceptible to VSV infection. The goal of this study was to elucidate the nature of the IFN defect in human HCC. We demonstrate here that the defect in IFN-beta signaling in HCC cells results from a deregulated IFN regulatory factor-3 (IRF3) pathway. Expression of IRF3-spliced variant (IRF3-nirs3) was constitutively observed in HCC cells and, importantly, also in primary HCC samples. In contrast, IRF3 was readily activated in PHHs after stimulation with dsRNA or infection with VSV. In addition, overexpression of IRF3-nirs3 significantly abrogated the IFN-beta response to VSV infection and improved viral growth. Our data provide evidence that aberrant splicing of IRF3 in HCC contributes to the defect in IFN-mediated antiviral defenses. This work may provide a potential molecular basis for selecting HCC patients for oncolytic VSV therapy in future clinical trials.
 ...
PMID:Inhibition of the IFN-beta response in hepatocellular carcinoma by alternative spliced isoform of IFN regulatory factor-3. 1878 Nov 39

Toll-like receptor 3 (TLR3) is a pattern-recognizing receptor that is involved in immune signaling and plays a crucial role in survival by being able to recognize various viral components including double-stranded RNA (dsRNA). TLR3 expression and function in cancer cells are not well understood. We investigated the expression of TLR3 in hepatocellular carcinoma (HCC) cells and the function of TLR3 signaling by stimulation and transfection with polyinosinic-polycytidylic acid (Poly I:C), a synthetic form of dsRNA. TLR3 mRNA was expressed in HCC tissues as well as in non-tumor tissues. Positive immunohistochemical staining for TLR3 was observed in 52.7% of HCC tissues, and in HCC cells we found both membranous and cytoplasmic expression of TLR3. While cell surface stimulation of TLR3 with Poly I:C did not affect cell viability, it did activate NF-kappaB levels. In contrast, cytoplasmic stimulation with transfected Poly I:C significantly induced apoptosis accompanied by the down-regulation of anti-apoptotic protein. Transfected Poly I:C also synergistically augmented TRAIL-induced apoptosis, but only with low levels of transfected Poly I:C was IFN-beta production not observed. In conclusion, our results indicate that TLR3 expression in HCC plays an important role with regard to cell survival and proapoptotic activity. Endogenously expressed TLR3 may provide new clinical prospects for TLR3 agonists as cytotoxic agents in HCC.
 ...
PMID:Dual topology of functional Toll-like receptor 3 expression in human hepatocellular carcinoma: differential signaling mechanisms of TLR3-induced NF-kappaB activation and apoptosis. 1894 55

Although reovirus has been used in tests as a potential cancer therapeutic agent against a variety of cancer cells, its application to hepatocellular carcinoma cells, in which the hepatitis B virus (HBV) X (HBX) protein of HBV plays a primary role, has not yet been explored. Here, we describe experiments in which we use reovirus to treat Chang liver carcinoma cells expressing either a vector only (Chang-vec) or a vector encoding HBX protein (Chang-HBX). Although Chang-vec cells readily support reoviral proliferation and undergo apoptosis, Chang-HBX cells are highly resistant to reoviral infection and virus-induced apoptosis, even though HBX protein induces activation of Ras and inactivation of PKR, which are normally thought to enhance reoviral oncolysis. The resistance of Chang-HBX cells to reovirus may instead be explained by HBX-induced downregulation of death receptor 5 and activation of Stat1. Phosphorylated Stat1 activates interferon (IFN)-stimulated regulatory element (ISRE)- and IFN-gamma-activated sequence (GAS)-mediated transcription, leading to the production of IFN-beta, whereas the reduced expression of Stat1 with its siRNA results in a decrease in IFN-beta production, by which Chang-HBX cells eventually succumb to reovirus infection. This result further indicates that HBX induces the establishment of an antiviral state through Stat1 activation. Thus, it appears that active Ras does not override the antiviral effect mediated by the activation of Stat1. Accordingly, we report that HBX, an oncoprotein of HBV, can prevent reoviral oncolysis of hepatocellular carcinoma. This suggests there may be limits to the practical application of reovirus in the treatment of human cancers already expressing other oncoviral proteins.
 ...
PMID:Expression of HBX, an oncoprotein of hepatitis B virus, blocks reoviral oncolysis of hepatocellular carcinoma cells. 1909 45

Toxicology studies were performed in rats and rhesus macaques to establish a safe starting dose for intratumoral injection of an oncolytic vesicular stomatitis virus expressing human interferon-beta (VSV-hIFNbeta) in patients with hepatocellular carcinoma (HCC). No adverse events were observed after administration of 7.59 x 10(9) TCID(50) (50% tissue culture infective dose) of VSV-hIFNbeta into the left lateral hepatic lobe of Harlan Sprague Dawley rats. Plasma alanine aminotransferase and alkaline phosphatase levels increased and platelet counts decreased in the virus-treated animals on days 1 and 2 but returned to pretreatment levels by day 4. VSV-hIFNbeta was also injected into normal livers or an intrahepatic McA-RH7777 HCC xenograft established in Buffalo rats. Buffalo rats were more sensitive to neurotoxic effects of VSV; the no observable adverse event level (NOAEL) of VSV-hIFNbeta in Buffalo rats was 10(7) TCID(50). Higher doses were associated with fatal neurotoxicity and infectious virus was recovered from tumor and brain. Compared with VSV-hIFNbeta, toxicity of VSV-rIFNbeta (recombinant VSV expressing rat IFN-beta) was greatly diminished in Buffalo rats (NOAEL, >10(10) TCID(50)). Two groups of two adult male rhesus macaques received 10(9) or 10(10) TCID(50) of VSV-hIFNbeta injected directly into the left hepatic lobe under computed tomographic guidance. No neurological signs were observed at any time point. No abnormalities (hematology, clinical chemistry, body weights, behavior) were seen and all macaques developed neutralizing anti-VSV antibodies. Plasma interleukin-6, tumor necrosis factor-alpha, and hIFN-beta remained below detection levels by ELISA. On the basis of these studies, we will be proposing a cautious approach to dose escalation in a phase I clinical trial among patients with HCC.
 ...
PMID:Safety studies on intrahepatic or intratumoral injection of oncolytic vesicular stomatitis virus expressing interferon-beta in rodents and nonhuman primates. 1991 74

Hepatitis C virus (HCV) is an important human pathogen that causes acute and chronic hepatitis, cirrhosis and hepatocellular carcinoma worldwide. This positive stranded RNA virus is extremely efficient in establishing persistent infection by escaping immune detection or hindering the host immune responses. Recent studies have discovered two important signaling pathways that activate the host innate immunity against viral infection. One of these pathways utilizes members of Toll-like receptor (TLR) family and the other uses the RNA helicase retinoic acid inducible gene I (RIG-I) as the receptors for intracellular viral double stranded RNA (dsRNA), and activation of transcription factors. In this review article, we summarize the interaction of HCV proteins with various host receptors/sensors through one of these two pathways or both, and how they exploit these interactions to escape from host defense mechanisms. For this purpose, we searched data from Pubmed and Google Scholar. We found that three HCV proteins; Core (C), non structural 3/4 A (NS3/4A) and non structural 5A (NS5A) have direct interactions with these two pathways. Core protein only in the monomeric form stimulates TLR2 pathway assisting the virus to evade from the innate immune system. NS3/4A disrupts TLR3 and RIG-1 signaling pathways by cleaving Toll/IL-1 receptor domain-containing adapter inducing IFN-beta (TRIF) and Cardif, the two important adapter proteins of these signaling cascades respectively, thus halting the defense against HCV. NS5A downmodulates the expressions of NKG2D on natural killer cells (NK cells) via TLR4 pathway and impairs the functional ability of these cells. TLRs and RIG-1 pathways have a central role in innate immunity and despite their opposing natures to HCV proteins, when exploited together, HCV as an ever developing virus against host immunity is able to accumulate these mechanisms for near unbeatable survival.
 ...
PMID:Interaction of Hepatitis C virus proteins with pattern recognition receptors. 2272 46

Hepatitis C virus (HCV) is the leading cause of hepatocellular carcinoma (HCC), and several antiviral agents are available for the treatment of chronic HCV infection. However, the impact of antiviral therapy on the long-term outcomes of HCV-related HCC patients remains inconclusive. We aimed to examine the impact of antiviral therapy on the long-term outcomes of HCV-related HCC patients. We conducted a systematic review using PRISMA guidelines to identify trials and English-language literature from PubMed, Ovid MEDLINE, Scopus and the Cochrane Library database till August 2014. Randomized trials of antiviral treatments examining the effects of antiviral therapy on CHC patients and HCV-related HCC patients were screened and selected. We identified 6 trials evaluated the effectiveness of interferon (IFN)-alfa treatment, 3 studies examined pegylated interferon-alfa treatment, and 2 studies examined IFN-beta treatment. IFN-based therapy may decrease HCC incidence in HCV cirrhotic patients after a >5-year follow-up, improve liver reserve, decrease HCC recurrence rate, and increase survival rate in HCV-related HCC patients after curative HCC therapy. In conclusion, IFN-based therapy is beneficial and may be recommended in the management of HCV-related HCC patients who are IFN eligible.
...
PMID:Systematic Review: Impact of Interferon-based Therapy on HCV-related Hepatocellular Carcinoma. 2596 67


<< Previous 1 2 3 4 5