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

Lymph node (LN) cells of Fas-mutant mice lpr/lpr (lpr) and lpr(cg)/lpr(cg) (lpr(cg)) express an increased level of Fas ligand (FasL) (CD95L). We examined the antitumor potential of cell-bound FasL on these LN cells against Fas+ tumor cells. Fas+ F6b and Fas- N1d cells were produced from murine hepatoma MH134 (Fas-) by gene transfection. lpr and lpr(cg) LN cells inhibited growth of F6b but not N1d cells in vitro. Neither gld/gld lpr/lpr (gld/lpr) LN cells, which lack both FasL and Fas, nor wild-type LN cells showed growth-inhibitory activities against F6b and N1d cells. The effector cells and molecule were CD4-CD8- T cells and FasL, respectively. The tumor neutralization test and adoptive transfer demonstrated that lpr and lpr(cg), but not gld/lpr, LN cells retarded the growth of F6b cells. Although anti-Fas antibody and FasL cause severe liver failure, wild-type mice injected with lpr LN cells appeared clinically normal. Adoptive transfer of lpr LN cells to F6b-bearing mice exerted the same antitumor activity in wild-type and gld/lpr recipient mice, indicating the applicability of cell-bound FasL for Fas-mediated target therapy of cancer. These results suggest that antitumor activity was dependent on the Fas-FasL system and that lymphoid cells overexpressing FasL can be powerful antitumor effector cells against Fas+ tumor cells.
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PMID:Antitumor activity exhibited by Fas ligand (CD95L) overexpressed on lymphoid cells against Fas+ tumor cells. 982 39

Hepatitis C virus (HCV) is a single-stranded RNA agent which expresses its genetic informations in the form of a single, large polyprotein encoded by an open reading frame (ORF) that extends through most of its genomic RNA. Proteolytic cleavage of the ORF product is essential for the virogenesis and the production of viral progeny. HCV is responsible for chronic liver disease, cirrhosis and possibly hepatocellular carcinoma. Viral persistence is considered the greatest problem in the management of HCV infection. It may result from several mechanisms, two of which are established. In the first, the high rate of genetic variations during viral replication results in the production of mutants capable of escaping the immune attack. In the second, the virus infects cells of the immune system itself, which represent a privileged site that cannot be reached by virus-specific T cell response. Involvement of lymphoid cells in the early stages of HCV infection may provide insight into the pathobiologic patterns of extrahepatic dissemination (lymph nodes, major salivary glands, kidneys, blood vessels). Dissemination of HCV-infected lymphoid cells throughout the organism is likely to maintain a mobile and extensive reservoir of the virus. In this respect, extrahepatic sites may act as a source of continuous reinfection of hepatocytes. Studies of intrahepatic B lymphocytes indicate that they are infected with HCV, clonally expanded and activated to secrete IgM molecules with rheumatoid factor activity. This strongly suggests that HCV directly stimulates B cell expansion, which may result in an indolent stage of lymphoproliferation (i.e., mixed cryoglobulinemia) or in frank B cell non-Hodgkin's lymphoma (NHL). The frequency of NHL, however, is much lower than that of HCV infection, suggesting that HCV alone is not able to induce tumors and that cellular events, in addition to the presence of virus and virus-encoded products, are necessary in order to obtain a malignant B cell phenotype. The demonstration of HCV productive infection in bone marrow-recruited and circulating pluripotent hematopoietic CD34+ stem cells indicates that HCV replication occurs in the early differentiation stages of hematopoietic progenitors. These are stable cell populations and are likely to represent the initial site of infection and a continuous source of virus production.
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PMID:Hepatitis C virus infection, mixed cryoglobulinemia, and non-Hodgkin's lymphoma: an emerging picture. 992 37

Traces of hepatitis B virus (HBV) genome can persist for years following recovery from hepatitis B. To determine overall duration, molecular characteristics, and pathological implications of this serologically undetectable form of hepadnaviral carriage, we have analyzed the expression of transcriptionally active virus genomes, their infectivity, and examined liver alterations during the natural lifespan of woodchucks convalescent from acute infection with HBV- related woodchuck hepatitis virus (WHV). In this study, we document lifelong persistence of scanty amounts of replicating virus both in the liver and lymphatic system after spontaneous resolution of an episode of experimental hepadnaviral hepatitis. Antibodies to virus nucleocapsid (core) were found to be the most reliable immunovirological marker coexisting with occult infection. In the majority of convalescent woodchucks, serial liver biopsies showed protracted minimal to mild necroinflammation with periods of normal morphology; however, hepatocellular carcinoma (HCC) ultimately developed in 2 of 9 animals studied. Inocula derived from lymphoid cells of convalescent animals induced classical acute hepatitis in virus-naive woodchucks that progressed to chronic hepatitis and HCC in 1 of the animals, demonstrating infectivity and pathogenic competence of the carried virus. Our results reveal that low levels of infectious WHV and residual hepatic inflammation usually continue for life after resolution of hepatitis and that this recovery does not avert HCC development. They also demonstrate that, in addition to the liver, the lymphatic system is the site of the occult lifelong maintenance of replicating hepadnavirus.
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PMID:Occult lifelong persistence of infectious hepadnavirus and residual liver inflammation in woodchucks convalescent from acute viral hepatitis. 1005

We have recently demonstrated by Northern blot and RT-PCR that the mRNA expression of the alpha-chemokine hIRH/SDF-1alpha is reduced in hepatocellular carcinoma (HCC), several digestive tract cancers and premalignant colon adenomas, and that its receptor CXCR4 mRNA expression is reduced in HCC. Here we investigate the expression of CXCR4 mRNA expression in several digestive tract cancers and hepatitis C viral (HCV) infected liver, a premalignant condition. There was no difference in the CXCR4 mRNA expression in colon, esophageal or gastric cancers compared to non-cancerous tissues. This is significantly different from the reduced expression we have seen with hepatocellular carcinoma (p<0.05). To better refine regional tumor or hepatic cytokine mRNA analysis within a biopsy sample we describe a micro-isolation technique for RNA extraction from portal and triad areas of liver biopsies or other small malignant or non-malignant biopsy samples suitable for use in RT-PCR and differential display reactions. In HCV liver biopsies, the expression of hIRH and its receptor CXCR4 mRNA, corrected for G3PDH, was not significantly different from that of control non-HCV (steatosis) biopsies. CXCR4 is expressed on leukocytes and its expression was predicted to correlate with hepatic inflammation. CXCR4 receptor mRNA expression did correlate significantly with that of its ligand hIRH/SDF-1alpha (p=0.001), and with the severity of fibrosis (p<0.05), but not with portal inflammation (p<0.10), piecemeal necrosis (p<0.10), lobular inflammation (p>0.10), the presence of lymphoid aggregates (p>0.10), or the total histological activity index (p=0.07). There was no difference in expression of hIRH or CXCR4 between responders and non-responders to interferon (IFN) treatment, while as a control, the responder group of patients did show a higher expression of IFNalpha receptor than the non-responder group (p=0.05).
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PMID:CXCR4 mRNA expression in colon, esophageal and gastric cancers and hepatitis C infected liver. 1020 Mar 42

A case of an inflammatory pseudotumor of the liver in a 75-year-old female with chronic hepatitis C whose radiologic features simulated that of hepatocellular carcinoma (HCC) is presented. On imaging studies, hypervascularity by CO2 ultrasound (US) angiography, enhancement at an early phase and isodensity at a late phase by incremental dynamic computed tomography (CT), perfusion defect by CT during arteriography (CTAP), and clinical background of hepatitis C virus (HCV) infection strongly suggested HCC. A US-guided needle biopsy revealed a mainly diffuse and polyclonal proliferation of lymphocytes positive for leukocyte common antigen (pan-lymphocyte cells), L-26 (B cell lymphocytes), and UCHL-1 (T cell lymphocytes), negative for both kappa and lambda light chains and sparsely distributed neutrophils and histiocytes. No lymphoid follicles were observed. The liver tissue around this tumor showed chronic hepatitis with mild activity and mild fibrosis. These histopathologic findings suggested that the diagnosis of inflammatory pseudotumor of the liver was tenable. As it is difficult to differentiate between inflammatory pseudotumor of the liver and HCC by imaging studies alone, supplemental biopsy, where possible, should be obtained when diagnostic imaging of tumors suggesting HCC is carried out. We emphasize that histopathology is a true gold standard in the diagnosis of this disease.
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PMID:Inflammatory pseudotumor of the liver in a patient with chronic hepatitis C: difficulty in differentiating it from hepatocellular carcinoma. 1050 40

Metallothionein I can be induced in response to a variety of agents that include heavy metals and oxidative stress. On the contrary, its induction was suppressed in some lymphoid-derived cancer cells. The mechanism of this repression has not been elucidated. Here, we show silencing of MT-I gene in a solid transplanted rat tumor as a result of promoter methylation at all the 21 CpG dinucleotides that span the region from -225 bp to +1 bp. By contrast, none of these CpG dinucleotides were methylated in the livers from the rats bearing the tumor, which was consistent with the efficient induction of the gene in this tissue by zinc sulfate. Genomic footprinting revealed lack of access of the transcriptional activators to the respective cis-acting elements of the methylated MT-I promoter in the hepatoma. The absence of footprinting was not due to inactivation of the metal regulatory transcription factor MTF-1, because it was highly active in the hepatoma. Treatment of the hepatoma bearing rats with 5-azacytidine, a demethylating agent, induced basal as well as heavy metal-activated MT-I gene expression in the hepatoma, implying that methylation was indeed responsible for silencing the gene. Bisulfite genomic sequencing showed significant (>90%) demethylation of CpG dinucleotides spanning MT-I promoter in the hepatoma following treatment with 5-AzaC. The hypermethylation of MT-I promoter was probably caused by significantly higher (as much as 7-fold) level of DNA methyl transferase activity as well as enhanced expression of its gene in the hepatoma relative to the host liver. These data elucidated for the first time the molecular mechanism for the silencing of a highly inducible gene in a solid tumor transplanted in an animal, as compared with the robust induction in the corresponding parental tissue and have discussed the probable reasons for the suppression of this gene in some tumors.
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PMID:Suppression of metallothionein gene expression in a rat hepatoma because of promoter-specific DNA methylation. 1061 49

Woodchuck hepatitis virus (WHV), similar to human hepatitis B virus, causes acute liver inflammation that can progress to chronic hepatitis and hepatocellular carcinoma. WHV also invades cells of the host lymphatic system, where it persists for life. We report here that acute and chronic hepadnavirus hepatitis is characterized by a profound difference in the expression of class I major histocompatibility complex (MHC) molecules on the surface of infected hepatocytes and, notably, lymphoid cells. While acute WHV infection is accompanied by the enhanced hepatocyte surface presentation of class I MHC antigen and upregulated transcription of the relevant hepatic genes, inhibition of class I antigen display on liver cells is a uniform hallmark of chronic WHV infection. This inhibition in chronic hepatitis occurs despite augmented (as in acute infection) expression of hepatic genes for class I MHC heavy chain, beta(2)-microglobulin, and transporters associated with antigen processing (TAP1 and TAP2). Further, the class I antigen inhibition is not related to the histological severity of hepatocellular injury, the extent of lymphocytic infiltrations, the level of intrahepatic gamma interferon induction, or the hepatic WHV load. Importantly, the antigen expression is also inhibited on organ lymphoid cells of chronically infected hosts. The results obtained in this study demonstrate that the defective presentation of class I MHC molecules on cells supporting persistent WHV replication is due to viral posttranscriptional interference. This event may diminish the susceptibility of infected hepatocytes to virus-specific T-cell-mediated elimination, hinder virus clearance, and deregulate the class I MHC-dependent functions of the host immune system. This multifarious effect could be critical for perpetuation of liver damage and evasion of the antiviral immunological surveillance in chronic infection and therefore could be supportive of hepadnavirus persistence.
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PMID:Posttranscriptional inhibition of class I major histocompatibility complex presentation on hepatocytes and lymphoid cells in chronic woodchuck hepatitis virus infection. 1077 84

The role of liver biopsy in hepatitis C viral infection is diagnostic and prognostic. It states diagnoses of chronic hepatitis, cirrhosis and hepatocellular carcinoma. The association of portal lymphoid nodules, inflammatory bile duct lesions and steatosis suggests an hepatitis C viral etiology. Liver biopsy allows grading (extent of necro-inflammatory lesions) and staging (amount of fibrosis) of the disease using scoring systems proposed by Knodell et al. and (or) by METAVIR group. It can be helpful in confirming (or refuting) the presence of secondary diagnoses such as alcohol-induce liver disease or haemochromatosis and in assessing the efficacy of antiviral treatments.
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PMID:[Diagnosis and histologic surveillance of hepatitis C]. 1090 92

The CD95 (also called APO-1 or Fas) system plays a major role in the induction of apoptosis in lymphoid and nonlymphoid tissues in response to a variety of extracellular signals, including chemotherapeutic drugs. Here we report that the CD95 ligand (CD95L) is upregulated in hepatoma cells upon treatment with antineoplastic drugs. Upregulation by different chemotherapeutic drugs is functionally relevant for drug-induced apoptosis and is mediated by transcriptional mechanisms. The MEKK1/JNKK pathway and a novel AP-1 element in the CD95L promoter downstream of the TATA box are required for CD95L upregulation. Thus, understanding the mechanisms of CD95-mediated apoptosis through CD95L upregulation upon treatment of hepatocellular carcinomas with chemotherapeutic drugs may contribute to the improvement of anticancer chemotherapy.
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PMID:A novel AP-1 element in the CD95 ligand promoter is required for induction of apoptosis in hepatocellular carcinoma cells upon treatment with anticancer drugs. 1100 76

The roles of lymphoid elements and apoptosis-related proteins in the development of extremely large hepatomas were studied in rats. Hepatoma cells were inoculated subcutaneously into 6-week-old rats, and 4 months later the quantities of T and B cells, macrophages, and cells positive for Fas, Fas ligand (FasL) and interleukin-2 (IL-2) were immunochemically evaluated in tumors. Grafting of hepatoma cells caused the development of giant tumors that could reach one-third of the rat's body weight. Within the hepatomas, almost all CD8(+) T cells were destroyed as they passed from the tumoral stroma into the parenchyma and came in contact with tumor epithelial cells. This could be the consequence of IL-2 production, since about 90% of tumor cells were CD25(+). The tumoral mass increased despite the significant increase in tumor necrosis. Cells with Ki67 or in mitosis, and cells positive for Fas and FasL were found only among tumor epithelial cells that were necrotic and never among viable cells. We suggest that progress in tumorigenesis is facilitated by inhibition of T helper cells, and the extensive death of T killer cells is caused by the high levels of the tumor produced IL-2.
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PMID:Tumor-induced insufficiency in T cell activity and hyperproduction of interleukin-2 in rat giant hepatomas. 1117 6


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