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)

Approximately 350 amino acid derivatives were synthesized and tested for antitumor activity in four tumor systems. The effect on life prolongation and tumor growth was examined using mouse leukemia SR-61, Ehrlich ascites carcinoma, ascites sarcoma-180, and rat ascites hepatoma (AH-60C). Among these 350 derivatives, 29 compounds were found to be significantly effective in prolongation of the median life-span and inhibitory effect on tumor growth in the primary screening. Among these 29 compounds, the following five compounds were found to possess potential antitumor activity: N-(2-Naphthalene)sulfonyl-DL-tryptophan (A-91), 2-naphthylaminomethyl-gamma-aminobutyric acid (A-144), N-ethylcarbaminomethyl-L-isoleucine (A-145), N-9-fluorenylacetyl-L-phenylalanine (A-192), and N-propionyl-L-valine (A-195). These five compounds were active in prolongation of the life-span of mice bearing Ehrlich ascites carcinoma and in the inhibition of the cell growth. Some of these amino acid derivatives inhibited biosynthesis of macromolecules, DNA, RNA, and protein, in tumor cells. These results suggest that the site of action of the five amino acid derivatives appears to result from the inhibition of macromolecules and another unknown mechanism.
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PMID:Antitumor activity of amino acid derivatives in the primary screening. 16 14

Tumor tissues obtained from 4 patients with the ectopic ACTH syndrome were studied for release and synthesis of tumor ACTH, using an in vitro incubation system. The effect of various agents on release of tumor ACTH was evaluated in three cases; beta-MSH released and adenosine 3',5'-monophosphate (cyclic AMP) formed in the tissue were determined in one. Biosynthetic experiments using labeled amino acid incorporation were performed in two cases. Secretion of tumor ACTH was significantly stimulated in all cases by crude rat median eminence extract which was also effective in stimulating beta-MSH secretion associated with elevated tissue cyclic AMP levels in one. Addition of cyclic AMP and dibutyryl cyclic AMP caused a significant increase in release of both tumor ACTH and beta-MSH in one. Biogenic amines (norepinephrine and serotonin) markedly elevated tussie cyclic AMP levels without a corresponding increase of hormone release in one. Incorporation experiments revealed that 3H- or 14C-phenylalanine was incorporated into immunoreactive ACTH of a larger molecular size (big ACTH) in both cases by chromatographic procedures. However, biological activity of big ACTH was found to be undetectable by an in vivo steroidogenic assay. A mild tryptic digestion of the big forms resulted in the appearance of little ACTH to which the major radioactive peak shifted. These data suggest that the mechanism of release of tumor ACTH and beta-MSH is very similar to that of the pituitary, and that intracellular cyclic AMP may in part play some role in release of both hormones. It is also suggested that some ectopic ACTH producing tumors predominantly synthesize big ACTH, a possible precursor of ACTH, with less bioactivity.
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PMID:In vitro release and biosynthesis of tumor ACTH in ectopic ACTH producing tumors. 16 26

Immunoperoxidase staining for Regan isoenzyme of alkaline phosphatase was performed on cryostat sections of five human tumor tisssues. With a direct immunoperoxidase staining for the localization of Regan isoenzyme at the light and electron microscope levels, sections previously fixed with 0.05 M phosphate-buffered 4% paraformaldehyde were reacted with rabbit antisera to human placenta alkaline phosphatase conjugated to horseradish peroxidase. Comparison of conventional histochemistry and immunohistochemistry for Regan isoenzyme indicated that strong specific immunoperoxidase staining appeared on the cell membrane surface, and a diffuse one, in the cytoplasm of lung and colon cancer tissue cells showing L-phenylalanine-sensitive alkaline phosphatase. No immunoperoxidase reaction was obtained in tumor cells showing sensitivity to L-homoarginine or lacking aklaline phosphatase activity.
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PMID:Direct immunoperoxidase staining for Regan isoenzyme of alkaline phosphatase in human tumor tissues. 18 52

When SV40 tumor cells (F5-1) in culture were treated with dibutyryl cyclic adenylic acid (DbcAMP),marked alterations occurred in their growth and morphology. Additionally, the incorporation or uptake of labeled thymidine, uridine, phenylalanine, and choline were reduced by this treatment. These modifications with DbcAMP exposure produced conditions simulating those of a contact-inhibited state. The immunization of hamsters with X-irradiated tumor cells previously cultured in the presence of DbcAMP indicated that the tumor-specific transplantation antigens and/or fetal antigens were altered during short-term expsoure to DbcAMP. Further examination of membrane antigens of SV40 tumor cells using the isotopic antiglobulin technique demonstrated a significant reduction in the tumor membrane antigen on cells cultured with DbcAMP.
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PMID:The effect of exposure to dibutyryl cyclic adenylic acid on the membrane antigenicity of SV40 tumor cells. 18 50

mRNA was isolated from cultures of AtT-20/D-16v tumor cells and translated in a mRNA-dependent reticulocyte cell-free system. The corticotropin (ACTH) product was purified by a double-antibody immunoprecipitation procedure using antisera specific for the alpha(1-24) sequence of ACTH. The product is shown by sodium dodecyl sulfate/gel electrophoresis and gel filtration on guanidine-HCl columns to be homogeneous with an apparent molecular weight (Mr) of 28,500. A product with the same molecular weight is synthesized when membrane-bound polysomes from D-16v cells are allowed to complete their nascent chains in a reticulocyte cell-free system. Mr 31,000 ACTH isolated from tumor cells has been separated into three proteins of different apparent Mr:29,000, 32,000, and 34,000. The cell-free product contains the same lysine-, methionine-, and phenylalanine-labeled tryptic peptides as the Mr 29,000 ACTH synthesized in the tumor cells. Tryptic peptide analysis also reveals the presence of the alpha(1-39) sequence in the Mr 28,500 cell-free product and suggests that there is only one copy of this sequence in the Mr 28,500 molecule.
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PMID:Characterization of a common precursor to corticotropin and beta-lipotropin: cell-free synthesis of the precursor and identification of corticotropin peptides in the molecule. 20 Sep 34

Addition of the ionophore A23187 to Y-1 mouse adrenal tumor cells in monolayer culture inhibits steroidogenesis and the steroidogenic response to corticotropin (50% inhibition at 1 . 10(-7)M). Inhibition is rapid in onset and is not overcome by addition of external Ca2+. The ionophore also inhibits stimulation of steroid synthesis by cyclic AMP. A23187 inhibits incorporation of the amino acid lysine into protein by Y-1 cells and the dose dependence of this inhibition closely resembles that of the inhibition of the steroidogenic response to corticotropin. Addition of A23187 to a subcellular system for protein synthesis prepared from Y-1 cells, inhibits incorporation of the amino acid phenylalanine into protein and this effect is not overcome by high concentrations of Ca2+. The inhibitory effect of A23187 on the response to corticotropin, like that response itself, takes place at some part of steroid synthesis after entry of cholesterol into the cells and before the side-chain cleavage of cholesterol. These studies confirm the importance of protein synthesis in the response to corticotropin and demonstrate that the effect of protein synthesized under the influence of corticotropin is exerted at some point in the events which bring substrate (cholesterol) to the mitochondrial side-chain cleavage enzyme system. It is also shown that A23187 inhibits protein synthesis, and hence the response to corticotropin, by a mechanism which is independent of the concentration of available Ca2+.
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PMID:Inhibition of steroidogenic response to corticotropin in mouse adrenal tumor cells (Y-1) by the ionophore A23187. Role of protein biosynthesis. 21 Aug 39

Activities of various hydrolytic enzymes were determined in rat organ homogenates and on the surface of cells from various sources, i.e., tumor cell strains, primary cultured cells, normal cells, and their transformants. Alanine, leucine, methionine, phenylalanine, and glycyl-proline aminopeptidases and esterase showed relatively high activities in all these organs and cells. In the kidney homogenate the aminopeptidase A activity was higher in other organs; i.e., the aminopeptidase A activity was lower than that of aminopeptidase B. Normal cells derived from kidneys showed the kidney-type pattern of amino-peptidases A and B on the surface of cells, whereas tumor cells from various origins were of another organ type. When cultured mouse fibroblast strain C3H2K and rat fibroblast strain 3Y1 cells were transformed by SV40 or by a ts A mutant and maintained at permissive temperature, aminopeptidase A activity was drastically decreased, and the ratio of aminopeptidase A to aminopeptidase B was reduced to the levels of tumor cells. If the ts A mutant-transformed cells were grown at the restrictive temperature, the ratio approached that of normal cells. In normal cells, however, cultivation at high or low temperature did not cause any change of the activities.
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PMID:Aminopeptidase activities on the surface of mammalian cells and their alterations associated with transformation. 21 Sep 41

A previous report from this laboratory showed that binding of iodine-labeled human choriogonadotropin to Leydig tumor cells is not a reversible process (Ascoli, M., and Puett, D. (1978) J. Biol. Chem. 253, 4892--4899). Most of the cell-bound hormone was found to be degraded to 3'-monoiodotyrosine before being released from the cells, and the degradation process could be inhibited by the lysosomotropic agents NH4Cl, chloroquine, and Triton WR-1339. It is reported herein that the degradation of receptor-bound human choriogonadotropin is an energy-dependent process, which can be inhibited by compounds that interfere with glycolysis or oxidative phosphorylation (e.g. NaF, NaN3, NaCN, and 2-deoxyglucose). Hormone degradation is also inhibited by some protease inhibitors such as the chloromethyl ketones of lysine and phenylalanine, but not by specific trypsin inhibitors (e.g. p-aminobenzamidine and p-tosyl-L-arginine methyl ester). With the exception of NH4Cl, it was found that the compounds which inhibit hormone degradation also inhibit hormone-stimulated steroidogenesis. However, the present results involving dose dependency, and those given in the following paper (Ascoli, M. (1978) J. Biol. Chem. 253, 7839--7843), indicate that these two phenomena are not related.
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PMID:Inhibition of the degradation of receptor-bound human choriogonadotropin by lysosomotropic agents, protease inhibitors, and metabolic inhibitors. 21 38

Both peptide elongation factors were purified from Zajdela and Walker tumors and from the host and normal liver. The activity of peptide elongation factor 1 from tumor tissues in promoting the binding of phenylalanyl-tRNA to ribosomes was significantly higher than that of normal liver. Also preparations from the host liver were markedly more active when compared with the corresponding factor from normal liver. Poly(U)-dependent phenylalanine polymerization was enhanced in subcellular systems containing elongation factor 1 from tumors or host liver. No differences were found between preparations of elongation factor 2 isolated from various sources. Tumor ribosomes showed an increased activity of both the acceptor and donor binding site of peptidyl transferase. In ribosomes from the tumor-host liver the activity of the acceptor site of this enzyme was decreased while that of the donor site remained unaltered. The enhanced activity of peptide elongation factor 1 from tumors and host liver is apparently the main reason of enhanced protein synthesis in these tissues. The enhanced activity of this factor is not specific for tumor growth as it occurs also in other pathological conditions.
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PMID:Protein synthesis in tumor host. II. Increased activity of peptide elongation factor 1 in experimental rat tumors and in host liver. 22 48

Two forms of therapy employed for treatment of patients with recurrent melanoma limited to the extremity, and carried out during different intervals of time, are presented. Perfusion of the involved extremity with phenylalanine mustard has resulted in a 5-year survival rate of 28% of 43 patients. A second group of 25 patients has been treated by a four-stage immunotherapy program consisting of sensitization with intradermal BCG, followed in 6 weeks by intra tumor injection of BCG. A third stage involved the activation of the patients's lymphocytes, after removal by a blood cell separator, incubated in vitro with irradiated neuraminidase-treated melanoma cells and reintroduced into the patient either by subcutaneous or intratumor injection. The fourth stage of immunotherapy involves injection of an inoculum of irradiated neuraminidase-treated autochothonous tumor cells plus BCG injected intratumorally or subcutaneously. Sixteen of 24 patients receiving immunotherapy treatment program have experienced arrest of their disease lasting from 5 to 42 months.
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PMID:Management of recurrent melanoma of the extremity. 23 93


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