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)

10(-4) M cycloheximide (CHM) inhibits leucine incorporation to about the same degree in slices of human lung tumors, rat hepatomas, regenerating livers and normal tissues. At 10(-6) M, CHM has a more pronounced effect on tumor tissue and regenerating liver than on normal tissues. 10(-8) M CHM stimulates protein synthesis in normal rat liver slices.
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PMID:Effects of cycloheximide on protein synthesis in human lung tumors, regenerating rat liver and hepatomas. 57 50

A case of multiple myeloma with no monoclonal protein synthesis is reported. The patient had hypogammaglobulinemia, bone marrow invasion, osteolytic lesions, and plasma cell tumors. The absence of protein synthesis has been demonstrated in bone marrow culture with tritiated leucine. No evidence of immunoglobulin production was found. Bone marrow or plasma cell tumor biopsy may be the only method of diagnosis in such cases.
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PMID:Nonsynthetizing multiple myeloma. 61 90

Cannabinoids represent a novel class of drugs active in increasing the life span mice carrying Lewis lung tumors and decreasing primary tumor size. In the present studies, the effects of delta9-THC, delta8-THC, and cannabidiol on tumor macromolecular biosynthesis were studied. These drugs inhibit thymidine-3H incorporation into DNA acutely, but did not inhibit leucine uptake into tumor protein. At 24 h after treatment, cannabinoids did not inhibit thymidine-3H incorporation into DNA, leucine-3H uptake into protein or cytidine-3H into RNA.
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PMID:In vivo effects of cannabinoids on macromolecular biosynthesis in Lewis lung carcinomas. 61 22

Tumor cells in a cytostatic state caused by macrophages and antibody were isolated. Such suppressed cells excluded vital dye, incorporated uridine and leucine, and metabolized glucose. They did not, however incorporate thymidine, nor did they resume cell division in culture. During prolonged culture, these cells eventually died. In this system, cytostasis was an all-or-nothing phenomenon at the level of the individual cell. Once in the cytostatic state tumor cells did not resume proliferation.
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PMID:Tumor cell cytostasis by macrophages and antibody in vitro. II. Isolation and characterization of suppressed cells. 65 62

Metabolic alterations in skeletal muscles and liver tissue from cancer patients were compared with corresponding alterations in mice (C-57) with sarcoma (MCG-101). In tumor-bearing man and mice similar changes in enzyme activities and in protein turnover were found. Glycolytic and oxidative enzyme activities were decreased in skeletal muscle tissue. Tumor-associated increase in lysosomal enzyme activities was found in both species. Leucine was incorporated into skeletal muscle proteins at a lower rate and into hepatic proteins at a higher rate in both species with malignant tumor. In tumor-bearing mice ribosome profiles from skeletal muscle, heart muscle and liver showed a preponderance of slowly sedimenting units of polyribosomes suggesting that initiation of protein synthesis may be a rate limiting step. The metabolic host reactions in tumor-bearing mice were similar to those in cancer patients implying that experimental tumors are relevant to use for analysis of mechanisms behind the development of cancer cachexia in man.
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PMID:A comparative study of the influence of malignant tumor on host metabolism in mice and man: evaluation of an experimental model. 67 48

The present study was designed to evaluate in a syngeneic system the longterm effect of dietary reduction of each of three essential amino acids on carcinogenesis with methylcholanthrene (MCA) and immunity to a transplanted MCA tumor. Inbred mice were provided a standard amino acid diet or a diet deficient in isoleucine, leucine, or phenylalanine-tyrosine. In the carcinogenesis experiment, MCA pellets were implanted in each mouse and weekly records were maintained of body weight, tumor incidence, tumor size, and death rate. Mice in the immunity study were inoculated with syngeneic tumor cells; tumors were excised when the largest tumor in the control group reached 12 mm and each animal then received a second challenge of tumor cells. The available data suggest that (1) restriction of the selected amino acids does not inhibit chemical carcinogenesis with MCA, (2) phenylalanine-tyrosine deficiency may actually enhance chemical carcinogenesis with MCA, and (3) selected essential amino acid deficiencies do not enhance immunity to a transplanted MCA tumor.
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PMID:Effects of essential amino acid deficiencies on syngeneic tumor immunity and carcinogenesis in mice. 68 45

In order to acquire a fundamental knowledge for the development of better tumor-scanning agents, the in vivo incorporation pattern of three 14C-labeled D-amino acids, alanine, leucine, and tryptophan, into the tumor cells and organs of animals bearing Ehrlich mouse tumor, sarcoma-180, leukemia L-1210, or Yoshida sarcoma was investigated, and compared with that of the corresponding L-forms. The radioactivity of D-amino acids tested was most highly found in tumor cells and pancreas, and the activity in tumor cells was several times higher than that of L-forms. A large portion of the radioactivity of D-forms was found in trichloroacetic acid-soluble fraction of the cells, whereas that of L-forms was mostly in protein fraction, except L-alanine. Although the mechanisms whereby the radioactivity of D-amino acids was concentrated more than that of L-forms in the tumor cells have not yet been clearly elucidated, it was concluded that gamma-emitter-labeled D-amino acids themselves or their derivatives might be useful as tumor-detecting radiopharmaceuticals.
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PMID:Preferential incorporation of some 14C-labeled D-amino acids into tumor-bearing animals. 71 Aug 3

The transfer RNA separation by chromatography on strong-base polystyrene exchange materials is examined and compared with the widely used reversed-phase chromatography. Results indicate important differences in some transfer RNA (tRNA) elution patterns by the anion-exchange chromatography, as compared with the reversed-phase chromatography. Transfer RNAs containing hydrophobic groups are adsorbed more strongly. The anion exchanger has twice the number of theoretical plates. Single peaks of tRNA2Glu and tRNA1Phe obtained from the reversed-phase column give multiple peaks only polystyrene anion-exchange chromatography. All six leucine tRNAs (Escherichia coli) and differences in tRNA populations synthesized during early and late stages of the dividing lymphocytes from normal human blood can be characterized by the anion-exchange chromatography. Different separation profiles are obtained by two separation systems for tyrosine tRNAs from mouse liver and mouse-plasma-cell tumor. The results indicate that, in contrast to the reversed-phase chromatography, strong-base-polystyrene anion-exchange chromatography is capable of separating tRNAs with minor structlral differences.
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PMID:Separation of transfer ribonucleic acids on polystyrene anion exchangers. 79 62

Several agents were compared for their ability to inhibit protein synthesis for long periods in tumor cells growing in culture. Mouse B16 melanoma cells, treated with high concentrations of cycloheximide or pactamycin for 1 hour and then washed repeatedly, recovered their ability to incorporate [3H]leucine into protein in about 4 hours, while cells treated with emetine recovered in 12 hours. After similar treatment with muconomycin A, however, incorporation of [3H]leucine remained inhibited for at least 30 hours. During this time the cells remained attached to the culture dishes, were able to exclude trypan blue dye, and retained nearly normal levels of rubidium-86 content. When another, untreated, population of cells was added to the muconomycin-treated cells, protein synthesis was not inhibited in the untreated population; action of the drug was thus shown to be confined to the treated cells. In melanoma cells treated with neuraminidase and muconomycin, measurement of glycoprotein synthesis (as determined by sialic acid analysis) showed that muconomycin also inhibited restoration of sialic acid content. Brief treatment with muconomycin, therefore, appeared to be sufficient for prolonged inhibition of protein and glycoprotein synthesis.
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PMID:Prolonged inhibition of protein and glycoprotein synthesis in tumor cells treated with muconomycin A. 83 56

The effect of pulverized plastic and glass-ceramic materials (methylmetacrylate, MNA), which are used as implantation materials in surgical medicine, on cell growth, DNA synthesis rate (adjudged by incorporation of 3H-thymidine into DNA), glucose consumption and lactate production (glycolytic rate) was studied in asynchronous monolayer cultures of rather fast proliferating Ehrlich ascites tumor cells and rather slowly proliferating diploid human fibroblasts. Exposure of Ehrlich ascites cells to high concentrations (2 mg/ml; 10 ml medium per culture) of ceramic or plastic material resulted in a gradual inhibition of cell growth and DNA synthesis rate. Protein synthesis, as measured by the incorporation of 3H-leucine, was somewhat less affected than DNA synthesis. Also, the glycolytic rate of Ehrlich ascites cells was slightly but significantly decreased in the presence of 2 mg/ml ceramics or MMA. Exposure of Ehrlich ascites cells to 0.2 or 0.02 mg/ml over a period of 46 h revealed none or only slight inhibitory effects on growth, DNA synthesis or glycolytic rate. On the other side, growth, DNA synthesis and glycolytic rates of human fibroblasts were nearly not affected by the presence of the same concentrations (up to 2 mg/ml, incubation period: 92 h) of pulverized ceramic or plastic material (MMA). It is suggested that this differential cellular sensitivity might be related to differences in the binding (to the cell surface) or uptake of these substances and possibly to differential intracellular lysosomal activation.
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PMID:Effect of pulverized implantation materials (plastic and glass ceramic) on growth and metabolism of mammalian cell cultures. 94 20


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