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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Two new human cholangiocarcinoma (CC) cell lines (CC-SW-I and CC-LP-I) were established and maintained in culture for 2 years. Histologically, both original liver tumors were adenocarcinomas, and the cell lines exhibited morphologic features of moderately differentiated adenocarcinoma. Immunohistochemistry showed that both cell lines were strongly positive for cytokeratin AEI but negative for carbohydrate tumor-associated antigen, CA19-9. Ultrastructural analysis of both cell lines showed the presence of tight junctional complexes and focally formed microvilli. Both CC cell lines were tumorigenic in nude mice. Cytogenetic analysis showed that both cell lines expressed highly aneuploid karyotypes with numerous structural and numerical deviations. CC-SW-I was hypodiploid with numerous chromosome losses and structural rearrangements, while CC-LP-I was hyperdiploid and displayed multiple additional chromosomes. Doubling times for the CC-SW-I and CC-LP-I cell lines in the presence of 15% fetal bovine serum were 72 hr and 180 hr, respectively. Growth of the CC-SW-I cell line was significantly stimulated in the presence of insulin, while that of the CC-LP-I cell line was significantly augmented by epidermal growth factor (EGF). In contrast, dexamethasone strongly inhibited proliferation of both cell lines in a dose-dependent manner. Among various recombinant cytokines examined for effects on growth or surface antigen expression on CC cell lines, only interleukin I-beta (ILI-beta) strongly inhibited growth of the CC-LP-I cell line, while interferons (IFNs) or tumor necrosis factor-alpha (TNF-alpha) were mildly inhibitory. Both tumor cell lines were resistant to natural killer (NK) cells but sensitive to lymphokine-activated killer (LAK) cells. Preincubation of tumor cells with IFN-gamma, IFN-alpha or TNF-alpha significantly decreased the susceptibility of each tumor cell line to lysis by LAK cells, and the change in sensitivity did not correlate with the expression of HLA antigens or intercellular adhesion molecule-I (ICAM-I) on the surface of tumor cells. These 2 CC cell lines are expected to provide valuable information about cell biology of human CC.
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PMID:Two new human cholangiocarcinoma cell lines and their cytogenetics and responses to growth factors, hormones, cytokines or immunologic effector cells. 135 57

Tumor cells often display alterations in their normal program of cellular differentiation. A promising approach for the treatment of cancer involves the induction of terminal differentiation and a loss of proliferative capacity in cancer cells. In human melanoma cells, the combination of mezerein (MEZ) and fibroblast interferon (IFN-beta), results in a rapid and irreversible suppression of cell growth with a concomitant increase in the synthesis of melanin. The induction of terminal differentiation is associated with alterations in the expression of several cellular genes, including fibronectin, ISG-15 and ISG-54, and changes in the expression of specific cell surface antigens, including intercellular adhesion molecule-1 (ICAM-1) and HLA Class I antigens. In the HO-1 human melanoma cell line, induction of terminal differentiation by MEZ plus IFN-beta results in an induction and/or increased expression of ICAM-1, HLA Class I antigens and HLA Class II antigens. IFN-beta and MEZ alone can modulate expression of these antigens to a lower extent than does the combination of compounds. Induction of terminal differentiation and the irreversible suppression of cell growth is not a prerequisite for antigenic modulation in HO-1 cells. This is indicated by the inability of immune interferon (IFN-gamma), a strong inducer of ICAM-1, HLA Class I antigens and HLA Class II antigens synthesis, or the combination of IFN-beta plus IFN-gamma which synergistically but reversibly suppresses HO-1 growth, to induce melanin synthesis or terminal differentiation in HO-1 cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Modulation of the antigenic phenotype of human melanoma cells by differentiation-inducing and growth-suppressing agents. 135 50

Recent studies have suggested that certain oncogenes, in particular members of the myc family, may be involved in the down-regulation of HLA class-I antigen expression observed in many types of tumor. We report that constitutive expression of an OK10 v-myc gene in human monoblastic U-937 cells results in a reduced expression of HLA class-I cell-surface expression and decreased levels of HLA class-I protein and mRNA. All class-I alleles, with the possible exception of HLA A3, were affected, as shown by one-dimensional isoelectric focusing (ID-IEF). Basal expression of the beta 2m chain was also reduced, although to a lesser extent. In addition, we show that the PMA-, and at least partially the IFN-alpha-induced increase in HLA class-I antigen expression, was inhibited in U-937-myc cells both at the protein and the mRNA level. In contrast, the response to IFN-gamma was normal. Another important difference in the response to IFN-gamma and alpha was that, while IFN-gamma abrogated the v-myc block of PMA-induced differentiation of U-937 cells, as previously reported, IFN-alpha did not. Our data show that v-myc negatively affects the regulation of both basal and inducible HLA class-I antigen expression.
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PMID:Suppression of basal, PMA- and IFN-alpha-, but not IFN-gamma-induced expression of HLA class I in v-myc-transformed U-937 monoblasts. 135 27

Neuroblastoma (NB), a tumor originating from the sympathetic nervous system, is the most common extracranial neurological tumor of childhood. Human NB cells may differentiate in vitro under treatment with biological agents, as gamma-interferon (IFN-gamma) and tumor necrosis factor (TNF). Unfortunately, NB cell lines resistant to the differentiation-inducing effects of both drugs have been observed. Here we demonstrate that a combination of IFN-gamma plus TNF causes extensive and generalized differentiation of NB cells toward a neuronal phenotype. Both IFN-gamma and TNF, given alone, moderately reduced cell growth and induced partial morphological maturation. Their combination further reduced cell proliferation. The combined treatment gave a synergistic rather than additive cytostatic effect, documented also by a dramatically enhanced differentiation toward a neuronal morphology. Membrane immunofluorescence showed a homologous and heterologous up-regulation of IFN-gamma receptor, as well as a marked induction of HLA Class I antigens and, to a lesser extent, of Class II antigens on NB cells induced to differentiate. Treatment of NB cell lines with IFN-gamma/TNF results in the induction of a differentiated phenotype, as indicated by the increased expression of the Mr 160,000 and 200,000 neurofilament proteins and that of microtubule-associated proteins. Evaluation of biochemical markers of neuronal differentiation confirmed the ability of the combined treatment to induce neuroblast maturation. These results suggest that the combination of IFN-gamma and TNF should be considered for experimental clinical trials in neuroblastoma.
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PMID:The combination of gamma-interferon and tumor necrosis factor causes a rapid and extensive differentiation of human neuroblastoma cells. 137 Oct 90

This study reports on biological response modification induced by prolonged continuous subcutaneous (s.c.) infusion of recombinant interferon-gamma (rIFN-gamma) with particular attention to changes of soluble CD14. This glycoprotein with an unknown function is derived from myeloid cells carrying membrane CD14, which is the receptor for lipopolysaccharide (LPS)-LPS-binding protein (LBP) complexes. Fifteen metastatic cancer patients received weekly escalating doses of rIFN-gamma starting at either 50 or 100 micrograms/24 h and increasing up to 400 micrograms/24 h for a median duration of 6 weeks. The maximum tolerated dose was higher (200 micrograms/24 h) with the lower (50 micrograms/24 h) starting dose. Biological activity of rIFN-gamma was evaluated by weekly measurements of CD14, neopterin, and beta 2-microglobulin concentrations in serum as well as monocyte HLA class I and II antigen expression and tumor cytotoxicity. Serum IFN-gamma concentrations increased 20-fold within 4 weeks of therapy. The levels were correlated to the mean dose (r = 0.95, p less than 0.05). Among the biological markers, two patterns were observed. First, serum CD14 concentration and expression of monocyte HLA class II antigens increased significantly during the first week, and marker expression correlated with serum IFN-gamma levels (p less than 0.05); CD14 and HLA class II antigens thereafter returned to pretreatment levels within 4 weeks of therapy despite persistently elevated serum IFN-gamma concentrations. Second, serum neopterin and beta 2-microglobulin concentrations as well as monocyte HLA class I expression also increased significantly within the first week, but remained elevated thereafter without any further dose relationship.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Prolonged interferon-gamma application by subcutaneous infusion in cancer patients: differential response of serum CD14, neopterin, and monocyte HLA class I and II antigens. 137 54

To facilitate investigation of its physical and functional properties, 11 monoclonal antibodies (mAbs) and a goat polyclonal IgG specific for the mouse interferon- (IFN-gamma) receptor were characterized and their potential uses studied. Eight of the mAbs interacted with epitopes on the extracellular domain of the receptor, two interacted with epitopes on the intracellular domain, and one interacted with an epitope that could not be localized definitively to either region. Of the 11 mAbs, the majority (8) were IgGs, 2 were IgMs, and 1 was an IgA. Relative avidities of the seven that could be determined ranged from 333 to 0.002 microM-1. Both the polyclonal goat IgG and mAb GR-20 (the latter specific for an epitope in the binding site for IFN-gamma) blocked binding of the ligand and, as expected, prevented induction by IFN-gamma of priming of macrophages for tumor cell killing. None of the other mAbs had an effect despite the fact that GR-22 partially (greater than 50%) blocked binding of IFN-gamma. Neither the polyclonal IgG nor any of the mAbs had an agonist effect. The relative usefulness of the antibodies for immunoprecipitation, immunoblotting, immunoassay, and cell staining with and without prior fixation is described. The results of immunocytochemical staining directly confirmed that the majority of immunologically reactive receptor protein expressed by cells is intracellular. To facilitate use by other investigators, the hybridomas that produce these mAbs will be offered to the American Type Culture Collection.
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PMID:Characterization and use of monoclonal and polyclonal antibodies against the mouse interferon-gamma receptor. 137 54

Nitric oxide (NO) is a short-lived biologic mediator that is shown to be induced in various cell types and to cause many metabolic changes in target cells. Inhibition of tumor cell growth and antimicrobial activity has been attributed to the stimulation of the inducible type of the NO synthase (NOS). However, there is limited evidence for the existence of such inducible NOS in a human cell type. We show here the induction of NO biosynthesis in freshly isolated human hepatocytes (HC) after stimulation with interleukin 1, tumor necrosis factor (TNF), IFN-gamma, and endotoxin. Increased levels of nitrite (NO2-) and nitrate (NO3-) in culture supernatants were associated with NADPH-dependent NOS activity in the cell lysates. The production of NO2- and NO3- was inhibited by NG-monomethyl L-arginine and was associated with an increase in cyclic guanylate monophosphate release. The data presented here provide evidence for the existence of typical inducible NO biosynthesis in a human cell type.
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PMID:Stimulation of the nitric oxide synthase pathway in human hepatocytes by cytokines and endotoxin. 137 25

Natural killer (NK) cells are probably involved in the elimination of virus-infected cells and of certain tumor cells. NK cell-mediated cytotoxicity (NK-CMC) was extensively studied and was found to consist of several steps. Following recognition and conjugation between the effector and the target cell, the latter one induces release of NK cytotoxic factor (NKCF) from the effector cells. The NKCF binds to the target cell which is subsequently killed. None of the molecules involved in these steps was completely characterized. In the present study it is demonstrated that isolated membranes of target cells can effectively induce the release of NKCF. Furthermore, the activity of such isolated membranes was found to be modulated by interferon (IFN) treatment of the cells prior to membrane isolation. It was therefore concluded that an NKCF-inducing structure (NKIS) is present on plasma membranes and is distinct from the NK-recognition structure. Similarly, the sensitivity to NK-CMC could be transferred from sensitive cells to IFN-gamma-treated (NK-resistant) cells by membrane fusion with the aid of Sendai virus envelope glycoproteins. It is proposed that transfer of NKIS is responsible for the acquired sensitivity to NK-CMC. In addition, it is shown that NKIS activity was recovered following membrane solubilization and reconstitution. Its level on cell surface was modulated by treatment of cells with tunicamycin, thus indicating that NKIS was probably a cell surface glycoprotein.
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PMID:An inducer of NKCF (NK cytotoxic factor) release: localization on target-cell membrane and initial characterization. 137 86

The interaction between LFA-1 and its natural ligand, ICAM-1, plays an important role in leukocyte adhesion and signal transduction. LFA-1-mediated T-cell adhesion is generally activated by CD3-mediated signal in association with T-cell receptor-mediated recognition of the antigen/major histocompatibility complex on antigen-presenting cells. In the present study, we compared spontaneous or bispecific antibody (BsAb)-directed LAK cell cytotoxicity against ICAM-1+ or ICAM-1- small cell lung cancer (SCLC) cell lines. gamma-Interferon (IFN-gamma)-induced ICAM-1 expression on ICAM-1- SCLC cell lines, and susceptibility to LAK cells was increased simultaneously. Increased cytolysis of the IFN-gamma-treated SCLC was inhibited by an anti-ICAM-1 monoclonal antibody (mAb). Furthermore, LAK cell cytotoxicity directed by BsAb, which was composed of OKT3 and anti-SCLC mAb, was also increased by the IFN-gamma treatment of SCLC, and this increase was inhibited by an anti-ICAM-1 mAb but not by anti-Class I or anti-CD2 mAb. These results suggest that a prior administration of IFN-gamma would enhance the efficacy of the following specific targeting therapy utilizing BsAb and LAK cells by up-regulating the ICAM-1 expression on tumor target cells. The combinational use of IFN-gamma and anti-CD3 x anti-tumor BsAb might be a promising way of enhancing LAK cell-mediated adoptive immunotherapy in small cell lung cancer patients.
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PMID:Induction of intercellular adhesion molecule 1 on small cell lung carcinoma cell lines by gamma-interferon enhances spontaneous and bispecific anti-CD3 x antitumor antibody-directed lymphokine activated killer cell cytotoxicity. 138 Dec 73

The hamster IgM mAb 5D3 is specific for an 73-kDa LPS receptor on murine leukocytes. This mAb inhibits binding of radiolabeled LPS to splenocytes and acts as an agonist for induction of LPS-mediated changes in macrophage function. Resident peritoneal macrophages treated with IFN-gamma and mAb 5D3 developed potent cytotoxic activity against tumor cells. Cells treated with IFN-gamma or mAb 5D3 alone were inactive. Macrophage cytotoxic activity induced by IFN-gamma and mAb 5D3 was inhibited by NGMMLA and coincident with high levels of NO2-released into culture fluids. These data show that mAb 5D3 serves as an effective trigger signal for induction of cytotoxic activity with IFN-gamma-primed macrophages. Indeed, mAb 5D3 exactly mimicked the effects of LPS in these same systems. Unlike LPS, effects of mAb 5D3 on induction of macrophage cytotoxic activity and production of nitrogen oxides was abrogated after boiling, and not affected by addition of polymyxin B. The effects of LPS and mAb 5D3 as a trigger signal for IFN-gamma-primed macrophages were associated with production of TNF activity in culture fluids and inhibited by mAb against rTNF-alpha. Expression of class II MHC on macrophages induced by IFN-gamma treatment was suppressed by both LPS and mAb 5D3. These suppressive effects of LPS and mAb 5D3 were not affected by NGMMLA or mAb against rTNF-alpha. Finally, macrophages treated with LPS or mAb 5D3 before exposure to IFN-gamma and LPS or mAb 5D3 did not develop cytotoxic activity or high levels of NO2- in the culture fluids. These same cells developed both effector activities after addition of rTNF-alpha. These results in toto identify the 73-kDa protein as a receptor that mediates LPS-induced changes in macrophage effector function. The mAb 5D3 serves as a specific and defined reagent agonist for analysis of LPS receptor-linked change.
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PMID:Cytotoxic activity and production of toxic nitrogen oxides by macrophages treated with IFN-gamma and monoclonal antibodies against the 73-kDa lipopolysaccharide receptor. 138 95


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