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 literature indicates that some mechanism other than the interferon or host-mediated immune enhancement might also be responsible for an antitumor effect of polyinosinate-polycytidylate [poly(I)-poly(C)]. We have examined the effect of this drug on the synthesis of ribosomes and other macromolecules in a rat tumor, the Novikoff ascites hepatoma. The nucleolus was one of the primary targets affected by the administration of poly(I)-poly(C) in vivo. A progressive decline of the activity of nucleolar ribosomal RNA methylases began within 2 hr, followed by a decline of the nucleolar RNA content. The activity of nucleolar RNA polymerase was inhibited only at later time intervals. Labeling of tumor macromolecules in vivo revealed that the methylation of ribosomal RNA and the production of ribosomes, particularly in the small subunits, were immediately and progressively affected, followed by inhibition of the synthesis of DNA, RNA, and protein at later times. In addition, poly(I)-poly(C) also induced disaggregation of polyribosomes and restricted the movements of nuclear RNA to cytoplasm and of cytoplasmic protein to nucleus. These in vivo effects of poly(I)-poly(C) on tumor cells was observed neither on the host livers nor on livers of normal rats. Studies on isolated nucleoli showed that the in vitro addition of polyinosinate and several other compounds actively inhibited tumor ribosomal RNA methylases but were devoid of inhibitory effect against liver ribosomal RNA methylases; these results augment other studies in the literature in suggesting a selective effect of the polyinosinate moiety on tumor cells. We conclude from this study that initial impairment of the methylation of ribosomal precursor RNA, following exposure of tumor cells to poly(I)-poly(C), is responsible for the destruction of ribosomes, preferentially the small subunits, during the maturation processes. Failure to provide new ribosomes thus triggers the events limiting the growth of tumor cells.
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PMID:Preferential inhibition by homopolyribonucleotides of the methylation of ribosomal ribonucleic acid and disruption of the production of ribosomes in a rat tumor. 16 54

Herpesvirus saimiri (HVS) is an oncogenic virus for a variety of nonhuman primates. HVS does not produce overt disease upon inoculation in the natural host (squirrel monkey) but consistently induces neoplasms including lymphomas and lymphocytic leukemias in 4 other species of monkeys. Various drugs inhibit replication of HVS in vitro including cytosine arabinoside and adenine arabinoside. In addition, the lymphoma and leukemia induced in owl monkeys responds to vincristine and prednisolone, cyclophosphamide, cytosine arabinoside, and human interferon. Of the various chemical carcinogens studied, the antitumor agent procarbazine induces neoplasms in a variety of species including monkeys. Thus far this compound has induced acute myelogenous leukemia (AML), lymphoma, and hemangiosarcomas in macaques. We have induced primary liver tumors in macaques with several nitrosamines and aflatoxin B1 and these tumors produce alpha-fetoprotein (AFP) which can be assayed for both diagnosis and therapy. Thus far, therapy of hepatocellular carcinoma has been most successful with surgical resection; and the tumor mass and serum AFP have been less responsive to single agent chemotherapy. These nonhuman primate models are useful for an understanding of the cause, diagnosis, prevention, and treatment of the human disease.
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PMID:Nonhuman primate models for lymphoma, leukemia, and other neoplasms. 16 36

PLC/PRF/5 hepatoma cells continue to produce hepatitis B surface antigen (HBsAg) after greater than 80 passages in vitro, but they do not express other markers of heaptitis B virus (HBV) replication. In this respect, they resemble most liver cells that are persistently infected with HBV. PLC/PRF/5 cells were cultured in the presence of adenine arabinoside, human fibroblast interferon, and ribavirin to determine whether production of HBsAg was sensitive to these antiviral agents. HBsAg released into culture media was detected by radioimmunoassay, and cellular protein synthesis was assessed by [3H]amino acid incorporation studies. A dose-related inhibition of HBsAg occurred with each antiviral agent that was tested, but in each case, this inhibition was matched by a reduction of cellular protein synthesis to a similar degree. Thus, no specific effect on the production of HBsAg was found with any of the antiviral agents tested.
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PMID:Lack of specific effect of adenine arabinoside, human interferon, and ribavirin on in vitro production of hepatitis B surface antigen. 52 92

The identification of the Hepatitis C virus using molecular cloning techniques, besides making the term Non-A Non-B Hepatitis obsolete, enables the development of specific assays for the detection of antibodies in HCV-infected individuals, thus making it possible to obtain sero-epidemiological data of the disease. The carriage of Hepatitis C antibody varies worldwide. The disease is most prevalent in intravenous drug abusers or haemophiliacs. Parenteral transmission is the most important route of transmission. Sexual, intra-familial and perinatal transmissions are uncommon. About 40% could be community-acquired (sporadic). Diagnostic tests include enzyme-linked immunosorbant (ELISA) anti-HCV assay, recombinant immunoblot assay, HCV-RNA by polymerase chain reaction and HCV-Ag. More than 50% of acute cases becomes chronic and runs a benign and indolent course. About 20% progress to cirrhosis and some of these develop hepatocellular carcinoma. Several published trials have consistently shown that treatment with interferon in some patients is useful. There is however a relapse rate of 50%. Further trials with interferon and other anti-viral agents like ribavirin are awaited for more effective treatment.
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PMID:Hepatitis C: an update. 128 40

Since the detection of hepatitis B virus (HBV) in the 1960s and hepatitis A virus in the 1970s, a considerable proportion of infections of (probably viral) hepatitis could not be classified. About 90% of transfusion-related hepatitis was identified as non-A/non-B. In 1988 investigators from the Chiron Company (USA) detected the non-A, non-B agent and named it hepatitis C virus (HCV). An anti-HCV antibody assay (ELISA) and subsequently confirmation tests (immunoblot and polymerase chain reaction) were developed. HCV infection results in a chronic carrier state of the virus in about 80%. Almost all HCV carriers have, irrespective of their liver function tests, histologic signs of chronic hepatitis and/or liver cirrhosis. Chronic HCV infection is, like HBV, also associated with the development of hepatocellular carcinoma. Most HCV carriers are infected by parenteral routes (intravenous drug use, blood transfusion, tattooing). Intravenous drug users and haemophilia patients have the highest risk (80-90%) of becoming infected. Sexual and perinatal transmission does not play an important role in spreading the infection. Antiviral therapy (alpha-interferon) in patients with chronic hepatitis C will normalize liver function tests in about 25% of the cases, but it is unclear if the HCV carrier state will disappear and if liver cirrhosis will be prevented. At present no specific immunoglobulin or vaccine preparations are available to prevent the HCV infection.
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PMID:New developments in hepatitis C. 129 54

The present paper reviews several studies performed between 1977 and 1986 in Singapore on the 10-year survival outcome of treatment for stage I and II hepatocellular carcinoma (HCC). Of 801 HCC patients evaluated, only 2 survivors (0.3%) remained in complete remission for 13 and 14 years, respectively. One had received four weekly cycles of prednisolone, Adriamycin, vincristine and 5-fluorouracil for an inoperable HCC with a 10-cm diameter, and the other had received localised synchronised hepatic irradiation and Adriamycin. As follow-up, the use of localised hepatic irradiation consisting of 131I-labeled (30 mCi) iodised oil in lipiodol infused via the hepatic artery appeared to benefit patients with small residual tumours but did not affect larger tumours measuring 2 cm in diameter. Prophylactic, intermittent long-term administration of lymphoblastoid interferon-alpha (Wellferon) was carried out in pre-cancerous, high-risk hepatitis B surface antigen (HBsAg)-positive patients with cirrhosis, in immediate male relatives of liver cancer patients, and in persons who had undergone hepatic resection. In the untreated group, 10/162 (6%) cirrhotics, 3/18 (17%) male family members, and 6/10 (60%) post-resection cases developed single or multiple HCCs within 1 year of screening done at 3-month intervals on the basis of alpha-fetoprotein (AFP) levels and real-time hepatic ultrasonography. In contrast, none of the Wellferon-treated group consisting of 518 cirrhotic patients, 82 male relatives of HCC patients and 20 post-resection cases developed HCC. Two HBsAg-positive individuals who had not been treated with interferon (IFN) developed hepatic nodules which that showed dysplasia, AFP elevation and chromosomal changes. These studies demonstrate the poor results of late diagnosis and show that early intervention and prophylaxis with Wellferon can reduce the incidence of HCC in high-risk persons. In addition, transhepatic chemoembolisation and liver resection are suitable methods for treating small HCCs (single or multiple) that are detected by screening. However, some of these early-detected HCCs remain highly malignant. Prophylactic treatment of pre-cancerous conditions appears to be a better option as a long-term programme for HCC.
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PMID:Long-term survival following treatment of hepatocellular carcinoma in Singapore: evaluation of Wellferon in the prophylaxis of high-risk pre-cancerous conditions. 133

In the treatment of active chronic hepatitis and hepatocellular carcinoma some effective drugs can produce myelosuppression. Hypersplenism may considerably limit the dosage of such drugs. Splenectomy is an effective treatment for hypersplenism, although it is not without complications. Partial splenic embolization is a good and safe procedure; 15 patients were treated in order to achieve higher platelet and leukocyte counts. Embolization has been performed with gelfoam with local and systemic antibiotics (Spigos' protocol) and 50-75% of the splenic parenchyma was infarcted. All patients could be treated for the underlying hepatopathy with adequate dosages of interferon or chemotherapeutic drugs.
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PMID:Splenic embolization prior to myelosuppressive treatment in hepatocarcinoma and active chronic hepatitis. 133 37

The anti-proliferative activity of human interferon (HuIFN) was enhanced by dipyridamole, 2,6-bis-(diethanolamino)-4,8-dipiperidinopyrimido-[5,4-d]-py rimidine, when tested against various human tumor cell lines, including KT (breast carcinoma), PLC/PRF/5 (hepatoma), MGC-I, U251-SP and T98 (glioma), HAC-2 and SHIN-3 (ovarian carcinoma), and MM-ICB (melanoma). The enhancement occurred irrespective of the kind of HuIFN used (alpha, beta or gamma) and the original degree of susceptibility of the cells to HuIFN. Even low doses down to 0.01 microM of dipyridamole that had no intrinsic anti-proliferative activity could enhance the effect of HuIFN. The enhancement of HuIFN effects seems not to be caused by induction of HuIFN production, because neither anti-viral activity nor HuIFN antigens were detected in culture medium in cells treated with dipyridamole. Mopidamole, a derivative of dipyridamole lacking one piperidine residue, produced little enhancement of the effects of HuIFN. Among ovarian cancer cell lines tested, the enhancement of the activity of HuIFN by dipyridamole for HAC-2 and SHIN-3 cells was equivalent to or greater than that for 3 chemotherapy agents (adriamycin, vincristine, and a camptothecin derivative). However, neither HOC-21 ovarian cancer cells nor HEC-1 endometrial adenocarcinoma cells were susceptible to any combinations. When MGC-1, U251-SP, and HAC-2 cells were injected into nude mice, the growth of tumors was more markedly inhibited by the subcutaneous administration of HuIFN in combination with oral administration of dipyridamole than by the HuIFN alone. Thus, this combination therapy seems to be worth trying for human cancer, although the enhancement of the effects of HuIFN by dipyridamole varied among the cell lines examined.
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PMID:Dipyridamole enhances an anti-proliferative effect of interferon in various types of human tumor cells. 137 1

Studies were undertaken to examine the effects of recombinant human transforming growth factor beta 1 (TGF-beta 1) on DNA synthesis and antiviral actions of interferons (IFNs) in HepG2 cell, a hepatoma cell line, transfected with hepatitis B virus (HBV) DNA. The inhibitory effects of IFN-alpha and -gamma on DNA synthesis of HepG2 cells were enhanced in a dose-dependent manner by a simultaneous addition of TGF-beta. The degree of suppression by the reagents was greater in HBV-nontransfected cells than in transfected cells. Inhibition of DNA synthesis was not due to direct cytotoxic effects of the additives, since the viability of HepG2 cells was comparable in the control and treated cultures as determined by trypan blue exclusion. Treatment of HBV DNA-transfected HepG2 cells with IFNs resulted in decrease in production of HB surface and e antigens, and in the level of HBV DNA, but TGF-beta reversed the IFN-induced antiviral state in HBV DNA-transfected HepG2 cells. TGF-beta had no direct effect on HBV replication. These results indicate that rTGF-beta 1 exerts a differential effect against the inhibitory actions of IFN on DNA synthesis and viral replication in HepG2 cells.
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PMID:Effects of transforming growth factor-beta 1 against the inhibitory action of interferon on DNA synthesis and viral replication in hepatitis B virus DNA-transfected cell. 138 17

In a rapid 51Cr release assay, peripheral blood mononuclear cells from 12 healthy donors did not lyse the hepatitis B virus deoxyribonucleic-acid-transfected human hepatoma cell line 2.2.15, but under the same experimental conditions they did lyse K562 cells. Peripheral blood mononuclear cells from 10 out of 16 patients with chronic active hepatitis B exhibited cytotoxic activity against 2.2.15 cells in the presence of a relatively reduced natural killer cell activity to the K562 cell target. Enhancement of the cytotoxic activity to 2.2.15 cells was statistically significant in the group of patients being treated with leukocyte alpha-interferon. The activity was not influenced by the degree of human leukocyte antigen type matching between effector and target, and was enhanced by depletion of T-cells and by in vitro interferon treatment. These results therefore support the concept of a natural killer-like cell activated by clinical administration of interferon in chronic active hepatitis B patients. This cell effector was lytic for the virus B negative HEP-G2 cells also. However, T-cells purified from a few patients failed to lyse the HEP-G2 while lysing the 2.2.15 target, thus indicating that a preferential recognition of the virus-infected target may be exerted by certain T-lymphocyte subsets. The use of the human leukocyte antigen type defined, highly differentiated, hepatitis B virus releasing 2.2.15 cell line as target for fresh lymphocytes in this cytolytic assay did not disclose cytolytic T-cells in an obvious way. Further manipulation of this system perhaps using T-cell clones may be the next step to exploit the investigative possibilities offered by the availability of the 2.2.15 cell target.
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PMID:Chronic active hepatitis B. Interferon-activated natural killer-like cells against a hepatoma cell line transfected with the hepatitis B virus nucleic acid. 164 27


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