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)

Previously, type C RNA tumor virus-related components have been described in blood leukocytes from patients with acute myelogenous leukemia. These components, for example, reverse transcriptase, have been shown to be most closely related to those from two oncogenic subhuman primate type C viruses (woolly monkey sarcoma virus and gibbon ape leukemia virus). Now, we report the continuous production of budding type C viruses with the same characteristic reverse transcriptase by three separate culturings of leukocytes from a single bleeding from a patient with acute myelogenous leukemia. These isolations were made possible by the discovery of a source of conditioned media which sustains exponential growth of human myelogenous leukemia cells in liquid suspension culture.
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PMID:Type C RNA tumor virus isolated from cultured human acute myelogenous leukemia cells. 4 23

The RNA-dependent DNA polymerase present in intracisternal A-type particles from mouse myeloma tumor cells has been studied. This polymerase can use either endogenous A particle RNA or an exogenous synthetic polynucleotide [poly (rA)] as a template. The DNA reaction product is small (4S-10S) and over 90% of it hybridizes to A particle RNA, whereas up to 50% of it hybridizes to murine sarcoma-leukemia virus RNAs. The RNA isolated from purified A particles is generally of low molecular weight (5S-15S) but contains small amount of 70S and 35S components. These results suggest that A-type particles may be related to C-type oncornaviruses.
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PMID:Characterization of DNA polymerase and RNA associated with A-type particles from murine myeloma cells. 4 84

In an evaluation of indium-111-bleomycin as a tumor-imaging agent, 357 whole-body tumor scans were performed in 293 patients. Of 246 studies performed in patients with a variety of active solid tumors, 218 (89%) were true-positive studies and 28 (11%) were false-negative. Of 69 scans in patients thought to be free of tumor after therapy, 32 (46%) were false-positive studies and 37 (54%) were true-negative. The true-positive rates by major tumor type were: adenocarcinoma of gastrointestinal tract origin (95%), lymphoma (88%), melanoma (87%), sarcomas (82%), lung (77%), breast (77%), childhood tumors (71%), gynecologic tumors (70%), and genitourinary tumors (68%). Soft tissue and lymphatic sites of tumor, both above and below the diaphragm, were easily visualized, whereas hepatic and bone marrow sites of involvement were less easily discerned. False-positive uptake with 111In-bleomycin was noted in lungs (6%), gut (3%), mediastinum (2%), normal breast tissue (0.8%), and in occasional inflammatory lesions. In 19 patients with multiple myeloma or leukemia, a pattern of diminished bone marrow uptake associated with abnormal accumulation of 111In-bleomycin in extramedullary sites of involvement was the rule. In another 23 patients in whom scans were performed because an occult tumor was suspected, scanning did not lead to specific diagnosis of tumor in a single instance. We conclude that 111In-bleomycin is a safe, effective, and useful new tumor-imaging agent in the initial staging and followup of patients with a variety of solid tumors. Significant advantages of this agent over other currently available radiopharmaceuticals include: A) a broader spectrum of tumors taking up the radio-pharmaceutical, and B) generally better delineation of abdominal and pelvic disease due to lack of interference from gut uptake.
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PMID:A clinical evaluation of indium-111 bleomycin as a tumor-imaging agent. 4 76

The oncornavirus related proteins associated with the surface of normal and malignant thymocytes were studied. Three virion-associated proteins (gp69/71, p45, p30) were associated with lymphoma cells from about 70% of the tumors studied. Two virion-associated proteins (gp69/71 and p45 were associated with normal thymocytes form some but not all strains of mice. In gp69/71- mice, conversion to the gp69/71+ phenotype accompanied leukemogenesis. An interesting difference in the apparent molecular size of virus related antigens of the 70,000 dalton size class was detected in lymphoma cells present in involved spleens as compared to involved thymuses. Mice infected as neonates with Scripps leukemia virus make antibody to gp69/71 and some make antibodies to molecules associated with the surface of their own tumors. The significance of the restricted presence of antigens coded for by the viral genome to the surface of some differentiated cells is discussed in reference to (a) the relationship between virion, leukemia associated, and differentiation dependent markers, and (b) the possible consequence to the host of having similar antigenic determinants on three independent structures with replicative potential (virus, normal thymocytes, and tumor cells).
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PMID:The oncornavirus glycoprotein gp69/71: a constituent of the surface of normal and malignant thymocytes. 4 9

Spontaneous regression and/or remission of Friend virus (FV)-induced splenic erythroblastic leukemia was observed in CD-1 mice infected with several isolates of FV. Regression of splenic tumor was accompanied by the loss of both specific FV-induced cell membrane antigen (FVMA) and virus group-specific antigens (gsa) from the spleen cells. The frequency (percentage) of immunoglobulin-positive cells (B) and thetapositive cells (T) in the spleen was markedly decreased during leukemia progression, but there was a subsequent increase during regression. The appearance of gsa-positive (gsa+) cells in peripheral blood correlated well with the early progressive and regressive phase of leukemia (up to 7 weeks after infection). Later, the presence of these cells became unpredictable in regard to status of disease. Gsa+ blood cells reappeared in most mice with regressed splenic tumors, suggesting persistence of the virus complex in the animals. Antibody responsiveness as determined by the numbers of hemolytic plaque-forming cells, PFC, after a single immunization with sheep red blood cells (SRBC), was suppressed in leukemia progression and recovered, spontaneously, during regression of leukemia. However, hemolytic PFC elicited by antigen in both progressors and regressors expressed the specific virus-induced membrane antigen, FVMA, detectable by the PFC-inhibition test with specific antiserum and complement. Recovery of immunological responsiveness also included the spontaneous appearance of virus-neutralizing antibody to FV. However, this was not paralleled by the appearance of antibody to FVMA. Traces of anti-FVMA antibody activity were occasionally detectable in serum of both progressors and regressors and did not correlate with virus neutralization, in individual mice; This may explain the susceptibility of regressors to secondary relapse and to reinfection.
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PMID:Expression of virus-associated antigens and immune cell functions during spontaneous regression of the Friend viral murine leukemia. 4 47

A transplantable myelogenous leukemia of an inbred Wistar/Furth rat has been established in tissue culture and cloned. The resulting transplantable leukemia line demonstrates in vitro doubling time of 20 hr, colony-forming efficiency of 5% in liquid and methylcellulos-containing medium, and a saturation density of 3.0 x 106 cells/sq cm in liquid medium. Following intraperitoneal inoculation, newborn rats developed solid tumors, ascities, and leukemia with ld50 of5 x 103 cells and mean latency of 60 days. The tumor cell morphology was consistent with that of acute myelogenous leukemia. Histochemical staining for myeloid enzymes revealed no evidence of myeloperoxidase, esterase, or leukocyte alkaline phosphatase; however, fluorescent antibody staining for lysozyme was markedly positive. Serum, urine, and ascitic fluid from rats with transplanted leukemia also contained elevated levels of lysozyme. There was no detectable type-CRNA virus production by this cell line after as long as 100 days in vitro. This inbred rat myelogenous leukemia should provide a useful model for studies of chemotherapy and immunoltherapy of human acute myelogenous leukemia.
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PMID:Acute myelogenous leukemia of the Wistar/Furth rat: establishment of a continuous tissue culture line producing lysozyme in vitro and in vivo. 4 87

Morphologic, tissue culture, immunologic, and biochemical methods have been used in an attempt to detect and characterize oncogenic viruses or their subviral components in cells derived from human prostatic carcinoma (PrCa) or benign prostatic hyperplasia (BPH). Electron microscopy was used to characterize the ultrastructural features of normal and neoplastic prostatic tissue. Examination of specimens of prostatic tissue from 34 patients with PrCa, ten patients with BPH, and three patients with bladder tumor (BT) revealed the presence of particles resembling type-C virus in three cases of PrCa and structures resembling budding type-C virus particles in one case of BPH. Fifty human prostatic tissue specimens have been set in tissue culture, of which 30 have been successfully grown for varying periods of time. Of 20 currently active cultures, nine consist primarily of epithelial cells. Immunofluorescence and mixed hemadsorption tests of cells derived from benign and malignant prostatic tissue and sera derived from patients with PrCa, BPH, BT, and other types of tumors, and from normal donors revealed that sera from patients with PrCa, BPH, or BT contain antibodies to antigens in cells derived from PrCa, BPH, or BT. The nature of these antigen-antibody reactions is under study. Initial biochemical studies have not detected reverse transcriptase in the tissue culture fluid from a small number of sparsely growing PrCa cultures nor specific gene sequences homologous to murine leukemia virus-Rauscher genomic RNA in preparations of either normal or malignant prostatic cell DNA. The results of these preliminary studies have demonstrated the applicability of the techniques employed to the study of the relationship of viruses to human PrCa and have provided a number of promising leads for further investigation.
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PMID:Virologic and immunologic studies of human prostatic carcinoma. 4 14

A molecular hybridization technique has been used to quantitatively measure the nucleotide sequence relationships of selected mammalian RNA tumor viruses. Reciprocal cross-hybridization tests were done in which a given radioactively labeled, viral genomic RNA species was annealed with an excess of unlabeled, complementary DNA product synthesized in endogenously instructed reverse transcriptase reactions. Hybrid formation was measured with pancreatic RNase A. Three representative mammalian RNA tumor virus groups were examined: murine viruses, simian viruses, and feline viruses. The results of reciprocal cross-hybridization testing have revealed that the murine viruses consist of four distinctly related subgroups: (i) the Friend leukemia virus/Rauscher leukemia virus subgroup, (ii) the Gross leukemia virus subgroup, (iii) the Moloney sarcoma virus subgroup, and (iv) the Kirsten sarcoma virus subgroup. Simian sarcoma virus, the only simian virus examined, appeared to share limited interspecies sequence relationships with members of the other virus groups and in particular with Kirsten sarcoma virus. Of the two members of the feline virus group tested, Rickard feline sarcoma virus and RD-114, each was placed in a separate, unrelated subgroup. Rickard feline sarcoma virus exhibited limited sequence relatedness with members of the other virus groups, whereas RD-114 exhibited none.
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PMID:Quantitative nucleotide sequence relationships of mammalian RNA tumor viruses. 4 42

The therapeutic activity of the narcissus residual alkaloid A-2 against Rauscher leukemia has been compared with 10 standard anticancer drugs, and synergistic or additive combination pairs have been selected using a viral leukemia and two transplantable tumor systems. An increased beneficial effect has been demonstrated by a combination of the alkylating and DNA-binding agents and the alkaloid against the three malignant tumors, while a beneficial effect by combining the alkaloid and the antimetabolites (either 6-MP or 5-azacytidine) was seen only against the viral leukemia. The alkaloid has no suppressive activity against cellular immunity as tested by PHA reactivity and allogeneic tumor rejection systems.
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PMID:Combination chemotherapy of Rauscher leukemia and ascites tumors by narcissus alkaloid with standard drugs and effect on cellular immunity. 4 97

Type C virions were spontaneously released from cultures of a diploid human cell strain. The varions have properties of known type C RNA tumor viruses and share antigenic determinants with the major interspecies-specific antigen (p30) of simian sarcoma virus. Antiserum to reverse transcriptase of gibbon ape leukemia virus inhibits the reverse transcriptase of the putative human virions and that of simian sarcoma virus, but has no effect on the corresponding enzymes of avian or murine RNA tumor viruses.
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PMID:Isolation of type C virions from a normal human fibroblast strain. 4 27


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