Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Irradiated syngeneic mouse testicular cells and the first-trimester human fetal tissue cells protect mice partially against tumors induced by methylcholanthrene or against a syngeneic transplantable mouse tumor, Meth A, respectively. For future research it is suggested that experiments should have a therapeutic rather than a prophylactic design and that the induction of tolerance to fetal antigens could be a highly informative procedure.
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PMID:The significance of embryonic reexpression in cancer. 97 3

Transplantability of mouse tumors superinfected with various kinds of membrane viruses was investigated in syngeneic hosts. Methylcholanthrene-induced fibrosarcomas in BALB/c mice, Meth A, and in C57BL/6 mice, BMT-, superinfected with Friend lymphatic leukemia virus in mice given neonatal injection of the virus, grew more slowly than uninfected tumors. The retardation of growths was not observed in mice that had been given injections of the virus at birth. Similarly, Meth A and a hepatoma in C3H/He mice, MH134, superinfected with Moloney murine sarcoma virus in nu/nu mice, had reduced their transplantability in respective syngeneic mice. Further, Meth A and MH134 superinfected with endogenous rat leukemia virus and human measles virus, respectively, in nu/nu mice also showed reduced transplantability, and some of the former were actually rejected by normal syngeneic hosts. On the other hand, the reduced transplantability was not found in irradiated mice, suggesting that the phenomenon was due to immunological events. However, a myelogenous leukemia in C57BL/6 mice, C1498, superinfected with Moloney sarcoma virus in nu/nu mice grew like uninfected tumor and did not show reduced transplantability at all.
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PMID:Reduced transplantability of syngenic mouse tumors superinfected with membrane viruses in nu/nu mice. 100 77

Host DNA synthesis-suppressing factor (DSF) produced into culture fluid of cloned HeLa cells (HeLa C-9) infected with a small plaque variant of Toyoshima strain of measles virus was purified by precipitation with ammonium sulfate, chromatography on CM-cellulose and DEAE-cellulose, and gel-filtration on Sephadex G-100 and G-200. The specific activity of the finally purified DSF was 302 units/mg of protein representing approximately 300-fold purification. The molecular weight of DSF was estimated to be about 55 000. By isoelectric focusing, two kinds of DSF having isoelectric points of 4.24 and 5.24 were detectable. The purified DSF was able to suppress host DNA synthesis of HeLa cells, continuous human lymphoid cells (NC-37), mouse L cells and Meth-A cells derived from an ascitic tumor of the mouse. The activity of the purified DSF was inactivated by heating at 56 C for 30 min or by treatment with trypsin.
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PMID:Purification of host DNA synthesis-suppressing factor (DSF) produced by infection with measles virus. 101 43

In studying "hemorrhagic necrosis" of tumors produced by endotoxin, it was found that the serum of bacillus Calmette--Guerin (BCG)-infected mice treated with endotoxin contains a substance (tumor necrosis factor; TNF) which mimics the tumor necrotic action of endotoxin itself. TNF-positive serum is as effective as endotoxin itself in causing necrosis of the sarcoma Meth A and other transplanted tumors. A variety of tests indicate that TNF is not residual endotoxin, but a factor released from host cells, probably macrophages, by endotoxin. Corynebacteria and Zymosan, which like BCG induce hyperplasia of the reticulo-endothelial system, can substitute for BCG in priming mice for release of TNF by endotoxin. TNF is toxic in vitro for two neoplastic cell lines; it is not toxic for mouse embryo cultures. We propose that TNF mediates endotoxin-induced tumor necrosis, and that it may be responsible for the suppression of transformed cells by activated macrophages.
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PMID:An endotoxin-induced serum factor that causes necrosis of tumors. 110 52

Following short-term suspension culture, cells from the Balb/C sarcoma Meth A were allowed to incorporate both [14C] leucine and 2-deoxy-D-glucose-1-[3H] (2DG). The 2DG is trapped as a small anionic marker of the cytosol. Deviation from the kinetics of spontaneous efflux of the markers is interpreted as reflecting perturbation of the target cell membrane. In the presence of guinea pig complement and a rabbit antiserum to Meth A, enhanced 2DG efflux was effected in a titer comparable to that detected with a 51Cr-release assay. With a number of alloantisera and syngeneic immune sera, 2DG efflux was enhanced while 51Cr-release was unaffected. Only in the presence of syngeneic immune sera from mice bearing a low tumor mass, syngeneic splenic leukocytes effect a retardation in the spontaneous 2DG efflux. Sera from animals with a large tumor mass were ineffective. Effux of proteins labeled with [14C] leucine was not altered. The phenomenon was not dependent on the presence of a heat-inactivatable syngeneic complement source. The method described provides a sensitive probe of target cell membrane permeability in the tumor model studied. The phenomenon detected is the capacity of serum, sampled relatively early in syngeneic oncogenesis, to direct syngeneic splenic leukocytes to interact with the target cell membrane differentially altering its permeability to the small cytosol marker.
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PMID:The use of 2-deoxy-D-glucose to assess changes in tumor target cell membranes in vitro. 120 22

We previously reported a dramatically increased number of macrophages in tumor-bearing mice. In this study, we investigated the involvement of CSF in that phenomenon. CSF-1 responding cells as macrophages precursors increased significantly in number in the spleens of tumor-bearing mice as compared with those in normal mice. Splenic cells and sera from the tumor-bearing mice respectively expressed CSF-1 in mRNA and serum protein levels, but failed to express the other CSF (granulocyte-macrophage-CSF or IL-3). Nonadherent splenic mononuclear cells (< 0.5% macrophages) from normal mice proliferated and differentiated into mature macrophages in culture within 7 days with recombinant mouse CSF-1 (rCSF-1). Both macrophages harvested from tumor-bearing mice and those activated in vitro with rCSF-1 expressed mostly Mac-1, -2 (and -3) Ag, showed yeast phagocytosis, produced IL-1 but not IL-2 or IL-3, and displayed potent cytotoxicity against NK cell resistant Meth-A tumor cells. These macrophages also expressed lipocortin I mRNA and secreted lipocortin I protein, and suppressed mitogenic responses of splenic lymphocytes. rCSF-1-activated macrophages derived from nonadherent splenic cells expressed both CSF-1 and CSF-1 receptor (c-fms) mRNA. Administration of rCSF-1 into normal mice induced hemopoietic and immunologic alternations similar to those observed in tumor-bearing mice. These results suggest that CSF-1 is involved in the dramatic increase of macrophages in tumor-bearing mice, possibly through an autocrine or paracrine loop.
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PMID:Role of colony-stimulating factor-1 in macrophage activation in tumor-bearing mice. 128 Nov 98

The effect of administration of PSK (Polysaccharide Kureha), a Coliolus preparation, in Meth-A solid tumors was analyzed in BALB/c mice. Spleen cells prepared from normal, non-treated Meth-A bearing, PSK-treated normal and PSK-treated tumor bearing mice were examined for induction of macrophage chemotatic factor (MCF). Only spleen cells from the latter mice produced MCF after 48 hrs of cultivation in the presence of Meth-A cells or concanavalin A (Con A). MCF-producing cells were indicated to be Lyt-1 positive, L3T4 positive and Lyt-2 negative cells in the negative elimination assay. There were no differences in the production of other cytokines including interleukin-2, interferon and tumor necrosing factor, spleen cells obtained other different groups of mice. The antitumor effect of either crude or purified MCF (molecular weight 100,000) was examined by daily consecutive intratumoral injections into Meth-A tumor tissues, and a significant inhibitory effect was detected.
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PMID:Antitumor effect of a Coliolus preparation, PSK: induction of macrophage chemotactic factor (MCF) in spleens of tumor bearing mice. 129 Jul 21

The effect of glycyrrhizin (GR), a Chinese herbal drug extracted from licorice roots, on the host resistance to tumors was investigated in a murine system. Administration of GR to BALB/c mice, which were inoculated s.c. with 1 x 10(6) cells/mouse of Meth A tumors, resulted in either no antitumor effect (8/20, 40%), a delay in tumor growth (9/20, 45%), or elimination of tumor growth (3/20, 15%) in these mice. In addition, the incidence of Meth A solid tumors was inhibited by GR when mice were inoculated with 1.5 x 10(4) cells/mouse or less of Meth A tumor cells, but not 7.5 x 10(4) cells/mouse or more. These results indicate that in this murine tumor system GR has a very weak antitumor effect. When GR at a dose of 20 mg/kg was administered to mice immunized with allogeneic lymphocytes 1 to 9 days after the immunization, the generation of suppressor macrophages (S-M phi) was clearly reduced as compared with that of S-M phi generated in immunized controls. In addition, when allospecific CTL (allo-CTL), which were generated in alloimmunized mice treated with GR followed by in vitro stimulation with allogeneic lymphocytes in a mixed lymphocyte reaction, were adoptively transferred to tumor-bearing mice treated with GR, the antitumor activity of allo-CTL derived from immunized mice treated with GR was markedly enhanced as compared with that of allo-CTL from immunized mice. Furthermore, established solid tumors were completely eliminated when interleukin-2 immunotherapy was performed in these mice in combination with GR treatments, but not interleukin-2 or GR alone.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Stimulation of host resistance against tumors by glycyrrhizin, an active component of licorice roots. 129 7

Hepatocyte growth factor (HGF) is a heparin-binding polypeptide mitogen for a variety of cell types including hepatocytes. HGF also has cytotoxic activity on some tumor cell lines as well as scattering activity on epithelial cells. In this study, recombinant human HGF was used to identify HGF-binding cell surface receptors on Meth A cells, whose growth is inhibited by HGF. Scatchard analysis of binding data indicated that there were two classes of binding sites with high affinity (Kd = 17 pM) and low affinity (Kd = 6.7 nM) and the average numbers were 6600 and 2,600,000 per cell, respectively. Affinity cross-linking of 125I-HGF to Meth A cells resulted in a major and a minor specifically labeled complex. Competition analysis followed by cross-linking indicated that the HGF-binding proteins were involved in the formation of the high-affinity binding. The existence of the two HGF-binding surface proteins was confirmed by HGF-dependent immunoprecipitation of the binding proteins with an anti-HGF polyclonal antibody. The molecular masses of the major and the minor surface proteins were 160 kDa and 130 kDa, respectively. The 160-kDa protein was autophosphorylated in vitro on tyrosine residue and was immunoprecipitated with an antiserum against the c-met proto-oncogene product. These results indicate that the 160-kDa HGF-binding surface protein on Meth A cells is the c-met protein. Furthermore, tyrosine phosphorylation of the c-met protein was stimulated by HGF treatment of Meth A cells, suggesting that it may be involved in the signal transduction of the growth inhibition of Meth A cells by HGF.
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PMID:Characterization of hepatocyte-growth-factor receptors on Meth A cells. 131 83

We have successfully generated cytotoxic monoclonal antibodies against a rat histiocytoma, AK-5. Monoclonal antibodies obtained after fusing immunized rat splenocytes with SP2/0 myeloma, were cytotoxic to AK-5 cells in the presence of complement. These monoclonals were highly specific and did not show any cross reactivity with normal cells and ascitic tumors such as Zajdela ascites hepatoma or Meth A. One of the antibodies was conjugated to daunomycin and used in the chemotherapeutic treatment. Total regression of AK-5 histiocytoma was obtained after injection of daunomycin-MAb conjugate into tumor bearing animals suggesting the specific targeting of the antineoplastic drug to the tumor. The histology of the tumor sections showed extensive necrosis of the tumors after treatment of the animals with drug-MAb conjugate.
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PMID:Generation of cytotoxic monoclonals against AK-5 histiocytoma: conjugation with daunomycin and use in chemotherapy. 131 80


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