Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A glycosyltransferase, CMP-N-acetylneuraminic acid : glycoprotein sialyltransferase was found in human malignant melanoma. Activities were measured with desialized glycoprotein as an exogenous acceptor. The enzyme was characterized by means of its pH optimum, 5.5, temperature optimum, 30 degrees C, KM values, 10 muM for the sugar nucleotide and 0.3 mM for desialized glycoprotein. It did not require exogenously added metal ions but was slightly stimulated by Mg2+. It required detergent for optimal activity. The effect of nucleotides and sugar nucleotides on enzyme activity has been investigated.
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PMID:[Sialyltransferase in human malignant melanoma]. 1 Jan 4

Using sensitive radiommunoprecipitation assays for highly purified type-C RNA tumor virus proteins, we found that 5 of 16 clinically normal gibbons (including 4 of 5 normal animals from a colony with 2 cases of lymphoma) and 4 of 4 experimentally inoculated gibbons formed antibodies to the major structural protein (p30) of gibbon ape leukemia virus (GaLV). An additional woolly monkey immunized with the closely related simian sarcoma virus also formed antibodies detectable with GaLV p30. Of 20 patients immunized with formalin-inactivated Rauscher murine leukemia virus (R-MuLV), 10 were previously reported to have antibodies to MuLV as determined by an internally labeled banded virus radioimmunoprecipitation assay. In comparison studies with purified R-MuLV proteins, 7 of 20 patients formed antibodies: 3/20 to R-MuLV p30 only, 1/20 to R-MuLV glycoprotein (gp) 70 only, and 3/20 to both p30 and gp70. Most responders were melanoma patients receiving immunotherapy with BCG. Additionally, rhesus monkeys produced antibodies to the endogenous cat virus RD114 and closely related endogenous baboon leukemia virus p30's. Thus these studies demonstrated the ability of primates (including humans) to form antibodies to well-characterized proteins from endogenous and exogenous type-C viruses and the potential utility of these assays for seroepidemiologic studies.
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PMID:Natural and experimentally induced antibodies to defined mammalian type-C virus proteins in primates. 17 68

Human malignant melanoma cell lines were found to bear Ia-like cell surface determinants demonstrable by hetero- or alloantisera and by direct identification of the characteristic bimolecular glycoprotein complex. Immunoprecipitation confirmed the presence of Ia determinants on the bimolecular complex. The quantity of Ia molecules determined by these methods and by absorption experiments was relatively constant for each cell line. Among different lines, however, the amount of Ia antigens ranged from a level equal to that expressed by B-cell lines to a small fraction of this amount. This variation in level of Ia contrasted with the more uniform amount of beta2-microglobulin detected on the cell surface. The Ia alloantigen specificity DRw2 was the most frequently encountered specificity. Ia determinants were also found on the surface of an epidermoid carcinoma line, but not on various other cell lines of normal or neoplastic origin.
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PMID:Expression of Ia-like antigens on cultured human malignant melanoma cell lines. 36 16

Cell surface glycoproteins of human tumor cell lines (melanomas and astrocytomas, and ovarian, bladder, stomach, cervical, laryngeal, and renal cancers) were studied by labelling with 1) neuraminidase-galactose oxidase-[3H]borohydride, 2) galactose oxidase-[3H]borohydride, and 3) dilute periodate-[3H]borohydride. The labeled components were examined by polyacrylamide gel electrophoresis and fluorography. Each tumor type had a distinctive pattern of labeled glycoproteins when the results from both procedures 1 and 2 were considered. Cell surface glycoproteins of malignant melanoma could not be labeled by procedure 2, whereas the other cell lines had at least two major glycoproteins that could be labeled by this method. Very similar profiles of melanoma glycoproteins were labeled by procedures 1 and 3. From these results the conclusion was reached that cell surface glycoproteins of melanomas are substituted with sialic acid so that their D-galactose and/or N-acetyl-D-galactosamine residues are available for oxidation by galactose oxidase only after neuraminidase treatment. An alternative explanation that these sugars are sterically accessible to galactose oxidase only after neuraminidase treatment also has to be considered. All melanoma lines studied were characterized by having two major cell surface glycoproteins with molecular weights of 110,000 and 90,000, respectively. Lines, however, varied considerably in their expression of other components. In particular, heterogeneity was shown in the expression of gp220, a component identified as fibronectin by immunoprecipitation with a specific antiserum, and in the expression of gp37/32, a pair of glycoproteins having the characteristics of la-like antigens. Of the other cell lines studied, astrocytomas most closely resembled melanoma in their glycoprotein profiles. The brain tumors, however, had two or three glycoproteins, including gp110, which could be labeled by galactose oxidase-[3H]borohydride without neuraminidase treatment.
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PMID:Cell surface glycoproteins of human tumor cell lines: unusual characteristics of malignant melanoma. 38 52

A partially purified glycoprotein fraction (the G-200 II fraction) obtained from sera of CD-1 mice sensitized with Corynebacterium parvum and treated with endotoxin was designated as tumor necrosis factor (TNF). Human melanoma cells exposed to this factor in vitro had decreased tumorigenicity when injected into nude mice. Human melanoma, embryonal adenocarcinoma of the testis and colon carcinoma heterotransplanted in nude mice exhibited regressions in size following intraperitoneal injections of TNF. The responses were related to dose and duration of exposure.
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PMID:Effects of murine tumor necrosis factor on heterotransplanted human tumors. 43 45

B16 melanoma cells were treated in vitro with muconomycin A, a long-lasting inhibitor of protein and glycoprotein synthesis, to reduce cellular sialic acid. Two i.p. inoculations of 10(7) muconomycin-treated cells into female C57BL/6 mice, followed by challenge with homologous live cells, resulted in a significant decrease in tumor incidence when compared to the results of inoculation with untreated cells (p less than 0.01). Inoculation of mice with cells treated with neuraminidase resulted in little or no decrease in tumor incidence. Effective immunity was dependent on the number of cells injected and was found only with the i.p. route of inoculation into female mice.
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PMID:Increased tumor immunity in mice inoculated with muconomycin A-treated B16 melanoma cells. 69 27

Serum proteins of cancer and control sera have been evaluated by the conventional Mancini method as well as by scanning densitometry measurements of components after separation by gradient PAGE. We established than in sera of cancer patients, prealbumin levels decrease and alpha 1-acid glycoprotein levels increase significantly. However, the Mancini method was not as sensitive as PAGE for quantitative evaluation of differences among sera of healthy adults, smokers, and patients with benign disease. We find that a more sensitive measure is the ratio between the two components (alpha 1-acid glycoprotein and prealbumin) and suggest that these values possibly may be useful as a CSI. In this study, the average CSI for healthy adults is 0.79, for heavy smokers, 1.24; for benign diseases, 1.67; and patients with various forms of cancer as follows: early lung, 4.17; late lung, 8.78; bladder, 8.92; colon, 13.77; breast, 2.43; and melanoma, 9.22.
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PMID:Evaluation of the relationships of prealbumin components in sera of patients with cancer. 74 71

Electrophoretic studies on malignant melanoma extracts before and after treatment with neuraminidase revealed that tyrosinase is a glycoprotein containing N-acetyl-neuraminic acid. Double diffusion tests using Concanavalin A and the lectin from Ricinus communis show that the carbohydrated chain of tyrosinase contains D-mannose as a sugar unit located within the carbohydrate chain. The terminal neuraminic acid groups are linked to D-galactose. The enzymatic activity of tyrosinase is not inhibited by Concanavalin A.
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PMID:Demonstration of carbohydrate structures in malignant melanoma tyrosinase. 81 68

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

A study of glycoprotein components in trypsin-digested material from the surface of isolated melanotic melanoma cells showed presence of amino sugars, protein-bound hexoses, fucose and sialic acids. The high content of fucose and low content of sialic acids in the surface material from the cells were striking.
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PMID:Surface glycoprotein components in isolated melanotic melanoma cells in the golden hamster. 87 93


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