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 high-molecular-weight RNA encapsulated with an RNA-instructed DNA polymerase in particles possessing the density characteristic of the RNA tumor viruses has been detected in 13 out of 14 human malignant melanomas. The [3H]DNA synthesized by these particles in an endogenous reaction hybridizes to RNA extracted from the human melanoma particulate structures, but not to RNA from normal skin. Similar particles containing RNA and enzyme have been found in basal cell and squamous cell carcinomas of the skin. The RNA of the melanoma particles is easily distinguishable by hybridization from the RNAs found in the particles of the basal and squamous cell carcinomas.
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PMID:Oncornavirus-like particles in human skin cancers. 5 74

A rapid propidium iodide staining method was used for analysis of single-cell suspensions of bone marrow and tumor biopsies by flow microfluorometry. With this technique, information on the proliferative status of target tissues can be obtained within 10 min of sample removal. DNA histograms and labeling index of sequential bone marrow biopsies from a patient with Stage IV diffuse lymphocytic leukemia and treated with 1-beta-D-arabinofuranosylcytosine infusion showed pronounced reduction in the percentage of cycling cells. In contrast, sequential tumor biopsies from a melanoma patient on methotrexate-citrovorum factor rescue therapy showed no changes. In sequential bone marrow biopsies of 3 patients on high-dose methotrexate-citrovorum factor rescue, initial accumulation of cells in G1-S (Day 1) was followed by a significant proliferative response (Days 4 to 7) and return to pretherapy values. In contrast, no recovery similar to that of the bone marrow was seen in tumor cells.
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PMID:Flow microfluorometric patterns of human bone marrow and tumor cells in response to cancer chemotherapy. 6 Jan 72

The mouse melanoma B16 contains particles encapsulating high molecular weight RNA of 60--70S size associated with a reverse transcriptase. The [3H]DNA synthesized by these particles possesses homology with RNA isolated from a hamster melanoma and from three human malignant melanomas.
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PMID:Particles from mouse melanoma B16 containing reverse transcriptase and 70S RNA related to human melanoma cytoplasmic RNA. 8 Jan 58

The mouse melanoma B16 contains particles encapsulating a high molecular weight RNA of 60--70S size associated with a reverse transcriptase. The particles possess a density of 1.14--1.18 g/cm3. The RNA shares sequences with the 70S RNAs of several mammalian C-type RNA tumor viruses. The nuclear DNA of the mouse melanoma B16 possesses particle-related sequences not present in the genome of normal C57BL mice.
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PMID:Biochemical studies on RNA tumor virus information and its transmission in B16 murine melanoma. 8 43

An RNA-direct DNA polymerase was purified from human melanoma tissue by successive column chromatography on DEAE-cellulose (DE-23 and DE-52) and phosphocellulose. The purified reverse transcriptase has a mol. wt. of 68,000, a pH optimum of 8.0, a Mn2+ optimum of 0.6 mM, and a KCl optimum of 60 mM. The purified enzyme transcribes (rA)n - (dT)12, (rC)n - (dG)18, (Ome-rC)n - (dG)18 and a 70s RNA from Rauscher leukemia virus (RLV), but failed to transcribe (dA)n - (dT)12. This enzyme has no terminal deoxynucleotidyl transferase activity. Serological studies have shown that the reverse transcriptase from human melanoma tissue is antigenically not related to DNA polymerases from Simian sarcoma virus (SiSV), Avian myeloblastosis virus (AMV), RLV, and human spleen of a patient with myelofibrosis. The purified enzyme showed a close antigenic resemblance to DNA polymerases from baboon endogenous virus (BEV) and rhabdomyosarcoma virus (RD-114), the endogenous virus of the cat.
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PMID:Biochemical and immunological characterization of a reverse transcriptase from human melanoma tissue. 8 88

Temporal changes in lymphocyte blastogenesis were studied using spleen cells from syngeneic melanoma-bearing and control mice fed various levels of purified diets containing 6, 10 or 30% casein. T-cell blastogenesis was stimulated by the presence of the tumor and these responses changed with the duration of feeding. In addition, protein concentration did not affect T-cell transformation but the level of energy intake influenced concanavalin A induced DNA synthesis. In contrast, the growing melanoma did not influence B-cell transformation whereas a very low level of dietary protein, a low level of energy intake and duration of the dietary manipulation influenced these cells. Tumor weights were generally not affected by the diet except in mice receiving a very low level of energy intake. Thus, we have found that B-cell responses were affected more than those of T-cells and that moderate protein deficiency did not enhance cellular immune responses in syngeneic tumor-bearing and control mice.
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PMID:Effects of low dietary protein concentration and energy deprivation on lymphocyte transformation in melanoma-bearing mice. 11 75

A series of 42 patients with malignant melanoma treated with BCG adjuvant immunotherapy were studied for sequential changes in cellular immune reactivity to non-specific mitogens. Lymphocyte preparations were made monthly and stored in a viable condition in liquid nitrogen. After 6 months of treatment, all lymphocyte samples from an individual were recovered and tested for DNA synthesis after stimulation with PHA, PWM, Con A, PPD and MLC. The responses to the mitogens in the blastogenesis test were stable during the course of therapy. The MLC response did not increase significantly in patients treated with tumor-cell vaccines, and declined sharply in the six patients who subsequently relapsed and died. The in vitro PPD response increased 1 to 3 months after initiation of BCG in patients who were initially unresponsive to PPD in vitro. However, PPD-positive patients did not show any significant alteration of the PPD response. The PPD response did increase less sharply in patients whose disease eventually recurred than in those who remained without evidence of clinical disease. BCG therapy does not appear to correct lymphocyte proliferative defects in melanoma patients. Of the assays employed, the MLC and PPD tests appear to be the most useful as monitors of clinical status and response to therapy.
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PMID:Sequential examination of lymphocyte proliferative capacity in patients with malignant melanoma receiving BCG immunotherapy. 13 80

Three mouse tumour cell lines grew continuously in 3 micro M 5-bromodeoxyuridine (BUdR). One line (MC-2) produced a retrovirus and altered in morphology in the presence of BUdR or 5-iododeoxyuridine (IUdR). These effects, which could be reversed by growth in normal medium were similar to those reported for the B-16 mouse melanoma line. The B-16 line used in this study, however, as well as a variety of human cells (six melanoma lines and three fibroblast strains), were much more sensitive to BUdR, 0.03-0.1 micro M being the maximum tolerated levels for continuous growth. No virus production or changes in morphology were induced in these cells by BUdR, deoxyuridine (UdR), 5-fluorodeoxyuridine (FUdR) or thymidine (TdR). The results of cell labelling and growth studies showed a correlation of incorporation of BUdR into DNA with toxicity. Compared on a competitive basis with 1 micro M TdR, the order of incorporation of 1 micro M nucleosides by two human cell lines was TdR = BUdR = IUdR greater than UdR greater than FUdR. In contrast to previous reports that FUdR is incorporated into RNA but not into DNA, half of the FUdR label was found in alkalistable, DNase-sensitive material. Over 90% of the other compounds was incorporated into DNA. All of the UdR and 60% of the IUdR label was incorporated as thymidine; this conversion could be inhibited by labelling in the presence of FUdR.
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PMID:Effects of thymidine analogues on murine and human cells. 16 36

Recent studies suggested that 3',5'-cyclic AMP (CAMP) may be involved in the regulation of cell proliferation and differentiation. Theophylline, an inhibitor of cyclic nucleotide phosphodiesterase, elevated intracellular cAMP. A melanotic clone of the B16 melanoma was treated with theophylline and studied in vitro and in vivo. With 12 hours after 1.0 mM theophylline was added to growing cultures, the number of cells incorporating tritiated thymidine (3-H-TDR) and the rate of uptake of 3-H-TDR into DNA were significantly reduced. After 7 days, the number of cells in the control cultures increased twenty-four times, whereas theophylline-treated cells increased only sixfold. Compared to the controls, the theophylline-treated cells contained ten times the melanin and an elevated cAMP content. Stimulation of melanogenesis and inhibition of proliferation increased progressively with duration of exposure to theophylline. After 5 days of culture with theophylline, cells were assayed for plating efficiency in theophylline-free medium. Although the number of colony-forming cells was unaffected by previous exposure to theophylline, the colonies were composed of fewer cells inoculated into syngeneic hosts were less tumorigenic than untreated cells. However, theophylline treatment of hosts bearing B16 tumors failed to reduce the tumor growth rate, and theophylline did not potentiate the growth inhibition resulting from treatment with the synthetic polyribonucleotide, polyinosinic-polycytidylic acid.
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PMID:Maturation and differentiation of B16 melanoma cells induced by theophylline treatment. 16 92

Spleen cells removed from C57Bl/6J mice bearing a methylcholanthrene-induced fibrosarcoma (MC-16) demonstrate suppressed responsiveness of phytohemagglutinin (PHA) and bacterial lipopolysaccharide (LPS) induced mitogenesis as compared to non-tumorous mice. A similar depression of PHA-induced mitogenesis was observed with spleen cells from C3H/HeJ mice bearing syngeneic mammary adenocarcinomas (C3HBA). The administration of indomethacin, a non-competitive irreversible prostaglandin (Pg) synthesis inhibitor, (75 or 100 mug/mouse, IP) on an alternate day basis to groups of tumor-bearing mice of both strains, significantly enhanced immune cell responsiveness to mitogenic stimulation. The addition of indomethacin (10 mug/ml) to cultures of spleen cells from these tumor-bearing mice, as well as to DBA/1J mice bearing the Cloudman S-91 melanoma, enhanced spleen-cell responsiveness to mitogen-induced DNA synthesis by as much as 156%. Indomethacin administration in vivo or in vitro had no significant effect on mitogen-induced DNA synthesis of spleen cells from non-tumor-bearing animals. It is hypothesized that tumors, or tumor-cell antigens, increase Pg production of a population of spleen cells, and that the increased Pg content of the spleen may be important in controlling immune responsiveness in mice.
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PMID:Indomethacin enhancement of spleen-cell responsiveness to mitogen stimulation in tumorous mice. 18 13


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