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)

The molecular mechanisms involved in the regulation of human immunodeficiency virus type 1 (HIV-1) replication may differ in various cell types and with various exogenous stimuli. TAR/Tat interactions play important roles in HIV-1-long terminal repeat (LTR)-directed transcription, and have become specific targets in molecular therapies for blocking HIV-1 replication. As we previously reported, astrocytic glial cells, which can support HIV-1 replication in cell culture and may be infected in vivo, provide an intracellular milieu in which TAR mutant HIV-1 viruses may replicate. In further studies of this molecular model, several divergent human cell types were analyzed for both TAR- and Tat-independent HIV-1 replication. Human hepatoma cell lines, which can be productively infected by HIV-1 after the hepatoma cells are transduced with the human CD4 receptor gene, were found to support high levels of HIV-1 replication. In these studies, utilizing a transient transfection system with wild-type and various TAR, Tat, or combined TAR/Tat mutant HIV-1 proviral constructs, we demonstrate TAR-independent replication in unstimulated human hepatoma cells. Remarkably, in human hepatoma cells, HIV-1 replication is not only independent of TAR but also can be independent of Tat expression. It is further demonstrated, using electrophoretic mobility shift assays (EMSAs) and an in situ UV cross-linking system, that human hepatoma cells contain novel endogenous cellular proteins that bind to the proviral HIV-1 5' LTR in the downstream region, between nucleotides +38 to +125 on proviral DNA. This alternative regulatory pathway of TAR- and Tat-independent viral production may provide a new system to dissect further the interactions of Tat/TAR and determine the role of the TAR element, in its DNA form, in HIV-1 replication.
AIDS Res Hum Retroviruses 1996 Aug 10
PMID:TAR- and Tat-independent replication of human immunodeficiency virus type 1 in human hepatoma cells. 884 14

Four new triterpene compounds, celasdin-A, celasdin-C, anti-AIDS celasdin-B and cytotoxic maytenfolone-A, were isolated from Celastrus hindsii. The structural determination of maytenfolone-A, celasdin-A, celasdin-B and celasdin-C, as well as the structure-activity relationships of these new compounds and derivatives, are discussed. Maytenfolone-A was further confirmed by X-ray studies. Biological evaluation showed that Maytenfolone-A demonstrated cytotoxicity against hepatoma (HEPA-2B, ED50 = 2.3 micrograms ml-1) and nasopharynx carcinoma (KB, ED50 = 3.8 micrograms ml-1). Celasdin-B was found to exhibit anti-HIV replication activity in H9 lymphocyte cells with an EC50 of 0.8 microgram ml-1).
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PMID:Antitumour and anti-AIDS triterpenes from Celastrus hindsii. 911 98

Metabolites derived from superoxide (O2.-) and nitric oxide (NO.) play an important role in antimicrobial and antitumoral defense, but may also harm the host. Low levels of such metabolites can also facilitate viral replication because of their mitogenic effects on cells. Most viruses grow better in proliferating cells, and indeed, many viruses induce in their host cell changes similar to those seen early after treatment with mitogenic lectins. Influenza and paramyxo-viruses activate in phagocytes in the generation of superoxide by a mechanism involving the interaction between the viral surface glycoproteins and the phagocyte's plasma membrane. Interestingly, viruses that activate this host defense mechanism are toxic when injected in the bloodstream of animals. Mice infected with influenza virus undergo oxidative stress. In addition, a wide array of cytokines are formed in the lung, contributing to the systemic effects of influenza. Oxidative stress is seen also in chronic viral infections, such as AIDS and viral hepatitis. Oxidant production in viral hepatitis may contribute to the emergence of hepatocellular carcinoma, a tumor seen in patients after years of chronic inflammation of the liver. Antioxidants and agents that downregulate proinflammatory cytokines and lipid mediators may be a useful complement to specific antiviral drugs in the therapy of viral diseases.
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PMID:Reactive oxygen species and nitric oxide in viral diseases. 915 14

We are giving an overview over the clinical features and different therapeutic options of HIV associated malignancies. There are three AIDS-defining malignancies: - Kaposi's sarcoma - Non-Hodgkin's lymphoma (NHL) - cervical cancer. In Kaposi sarcoma there is a broad therapeutic spectrum from cryotherapy to systemic chemotherapy depending on the site and stage of the Kaposi sarcoma. In NHL early therapeutic intervention is necessary because of the fast progress of the tumor. The cervical cancer in HIV-infected women seems to be more aggressive than in non-infected and also needs early therapeutic intervention. Many other tumors seem to occur more frequently in patients with HIV infection: anorectal cancer, malignant testicular tumors, lung cancer, Hodgkin's lymphoma, basal cell carcinoma, squamous cell carcinoma, and even malignant melanoma. The cancer incidence in HIV-patients seems to be higher among nonblacks. Most of the immunodeficiency associated tumors are virus induced and they are accompanied by a persistent viral infection, including HHV-8 in Kaposi's sarcoma; Epstein Barr virus (EBV) in NHL; and human papillomavirus (HPV) in cervical cancer. But there are also types of virus induced tumors which are not frequently associated with HIV-infection like the primary hepatocellular carcinoma in patients with hepatitis B virus infection.
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PMID:Clinical manifestations and therapies of AIDS associated tumors. 950 54

Immunodeficiency, be it congenital, therapeutic, or infectious in origin, increases the risk of certain, but not all, types of cancer. A common feature of these cancers is that specific infectious agents appear to be important in their etiology, not only in immunodeficient subjects but also in the general population. People with acquired immunodeficiency syndrome (AIDS) are at an increased risk of Kaposi's sarcoma, non-Hodgkin's lymphoma, Hodgkin's disease, squamous cell carcinoma of the conjunctiva, and childhood leiomyosarcoma. It is striking that most of these cancers have been associated with specific human herpesvirus (HHV) infections: HHV-8 with Kaposi's sarcoma and the closely related Epstein-Barr virus with non-Hodgkin's lymphoma, Hodgkin's disease, and possibly also with childhood leiomyosarcoma. Moreover, similar associations between these viruses and cancer have been found, albeit inconsistently, in people who are not immunosuppressed. Further research is needed to establish whether the risk of other cancers is also increased in people with AIDS, although, if so, the cancers are likely to be rare or to have comparatively small associated relative risks. Existing evidence suggests that there may be no marked increase in the risk of two common cancers that are known to be caused by infectious agents--hepatocellular carcinoma and invasive carcinoma of the uterine cervix. The apparent lack of an increase in invasive cervical cancer is unexpected and needs further investigation, especially since the prevalence of cervical infection with human papillomaviruses and of low-grade preneoplastic changes in the cervical epithelium is increased in women with AIDS. With the prospect of improved survival in people with AIDS, the effect of immunosuppression on cancer is likely to become an increasingly important issue.
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PMID:Overview of the epidemiology of immunodeficiency-associated cancers. 970 94

Extended schedules of oral etoposide have been evaluated in many types of advanced cancer. In addition to their use in the common solid tumours, extended schedules have been employed in Kaposi's sarcoma (both AIDS-related and endemic types), medulloblastoma, glioma, and hepatocellular carcinoma. Single agent activity was demonstrated in all of these tumour subtypes. For patients with carcinoma of unknown primary site, we have recently incorporated a 10-day oral etoposide schedule into a combination regimen that also includes paclitaxel and carboplatin. With this regimen we achieved a 47% response rate in a group of 53 evaluable patients, with a median survival of 13.4 months. Patients with adenocarcinoma and poorly differentiated carcinoma of unknown primary site had comparable response rates and survival. According to a large number of clinical trials and pharmacokinetic data, a daily oral etoposide dose of 50 mg/m2 consistently produces serum concentrations >1 mg/L for several hours each day. Lower doses fail to consistently produce this serum concentration, which is considered necessary for optimum tumoricidal activity. Optimal dose duration is 10 to 14 days, particularly when combination regimens are being employed. Oral etoposide has an established role as a single agent in patients with low grade non-Hodgkin's lymphoma, Kaposi's sarcoma, and testicular cancer (if residual carcinoma is resected after first-line treatment). The optimal use of extended-schedule etoposide in combination regimens is not defined but is being evaluated in a number of etoposide-sensitive malignancies.
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PMID:Extended-schedule oral etoposide in selected neoplasms and overview of administration and scheduling issues. 1071 42

It has been estimated that presently hepatitis B kills more people every day than AIDS kills in a year world-wide. Infection with hepatitis B produces a wide range of manifestations ranging from asymptomatic carriers to persistent infections leading to chronic liver diseases and hepatocellular carcinoma. Availability of effective and safe vaccine has made all this preventable. To formulate on appropriate vaccination strategy for India the epidemiology of hepatitis B needs to be defined. This report critically reviews the available data. The burden of long term sequelae of HBV infection is probably under-diagnosed and under-reported in India. Prevalence studies of HBV markers indicate that India falls under the area of intermediate endemicity. Limited data on age-specific prevalence of HBV markers suggests that the majority of the infection seems to take place below 15 years of age, and most of it under one year. Perinatal transmission appears to contribute significantly to the carrier pool. Childhood vaccination for HB among the general population is the obvious strategy of choice. But more information is required to decide on the timing of the first dose.
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PMID:Epidemiology of childhood hepatitis B in India: vaccination related issues. 1082 39

Insulin-like growth factor (IGF) binding protein-1 (IGFBP-1) is a 28-kDa plasma protein that binds to IGF-I and IGF-II with high affinity. IGFBP-1 is elevated in the blood as a result of sepsis, AIDS, excessive alcohol consumption, and diabetes and may, in part, be responsible for the wasting observed during these pathophysiological conditions. The liver is the principal site of IGFBP-1 synthesis, and we have previously shown that proinflammatory cytokines can directly stimulate IGFBP-1 secretion in a human hepatoma cell line (HepG2). The purpose of the present study was to investigate the role of the MAP kinase pathway in regulating IGFBP-1 synthesis by IL-1beta. We show that IL-1beta stimulates the phosphorylation of ERK-1 and -2 in a time- and dose-dependent manner. In addition, the MAP kinase-kinase MEK-1 and the ribosomal S6-kinase RSK-1 are also phosphorylated in response to IL-1beta. The transcription factor CREB, a potential substrate of both protein kinase A (PKA) and RSK-1, is phosphorylated in response to IL-1beta and cAMP in HepG2 cells. The ability of IL-1beta to stimulate the expression of IGFBP-1 and the phosphorylation of the above kinases was specifically inhibited by PD98059, a MEK-1 inhibitor. cAMP also stimulated IGFBP-1 synthesis, but PD98059 failed to block the cAMP effect. Conversely, a PKA inhibitor (H-89) inhibited the ability of cAMP, but not IL-1beta to stimulate IGFBP-1 synthesis. The effect of IL-1beta and cAMP on IGFBP-1 messenger RNA (mRNA) accumulation was additive. IL-1beta, cAMP, PD98059, and H-89 had similar effects on the accumulation of IGFBP-1 protein and mRNA. IL-1beta and cAMP did not change the half-life of IGFBP-1 mRNA, but PD98059 and SB202190, a p38 MAP kinase inhibitor, destabilized IGFBP-1 mRNA and blocked the phosphorylation of RSK-1 in response to IL-1beta. Our data demonstrate that the MAP kinase signal transduction pathway plays an important role in the regulation of IGFBP-1 synthesis by IL-1beta.
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PMID:Stimulation of insulin-like growth factor binding protein-1 synthesis by interleukin-1beta: requirement of the mitogen-activated protein kinase pathway. 1096 86

Several studies have suggested that the progression of hepatitis C virus (HCV) infection is more severe in patients infected by the human immunodeficiency virus (HIV). Two national retrospective multicenter cohort surveys were performed in France that included 17,487 HIV-infected patients during 1995 and 26,497 during 1997. The following data was evaluated: total number of deaths; number of deaths linked to AIDS, cirrhosis, or hepatocellular carcinoma (HCC); and number of deaths related to other (non-HCV--linked) causes. In 1995, the causes of death were as follows: AIDS, 1307 (7.47%); cirrhosis or HCC, 21 (0.12%); and other (non-HCV--linked) causes, 99 (0.56%). In 1997, the causes of deaths were as follows: AIDS, 459 (1.73%); cirrhosis or HCC 36 (0.13%); and other (non-HCV--linked) causes, 48 (0.18%). Comparative results between the 1995 and 1997 surveys showed a dramatic decrease in AIDS-related mortality rates (7.47% vs. 1.73%; P<.001) but not in HCV-related mortality rates (0.06% vs. 0.07%; P=.79). In France, despite the high prevalence of HCV infection in HIV-positive patients, the mortality rate in 1995 and 1997 caused by HCV-related cirrhosis or HCC was low.
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PMID:Mortality among human immunodeficiency virus-infected patients with cirrhosis or hepatocellular carcinoma due to hepatitis C virus in French Departments of Internal Medicine/Infectious Diseases, in 1995 and 1997. 1164 33

There has recently been an observable increase in some forms of cancer the world over. This is attributable in large part to the introduction of acquired immunodeficiency syndrome (AIDS)-related malignancies into the world of medicine and it is interesting that most of these cases are seen in the developing world, which proportionately leads with the number of AIDS cases. Despite this, some more traditional cancers remain the big killers in these areas of the world, except that in some countries definitive interventions have yielded excellent results in reducing disease burden. In Africa and the developing world, hepatocellular carcinoma (HCC) is the leading cause of cancer death, having some clearly established etiologic factors. This review describes the current status of each of these known etiologic factors in the various areas and, using available evidence, suggests options that may be employed to further stem the incidence of HCC and improve on survival in these populations. Semin Oncol 28:179-187.
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PMID:Hepatocellular carcinoma in the developing world. 1130 81


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