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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human hematopoietic cell lines, which had been classified on the basis of studies on clonality, and morphological, chromosomal and functional parameters as lymphoblastoid cell lines (LCL) of presumed non-neoplastic origin, and lymphoma, myeloma and leukemia lines of proven malignant origin, were tested for tumorigenic potential on subcutaneous transplantation to nude mice and for capacity to grow in semi-solid medium in vitro. Recently established LCL failed to grow both in nude mice and in agarose. In contrast, some of the LCL which had developed secondary chromosomal alterations during continuous cultivation for periods exceeding several years were tumorigenic and/or had the capacity to form colonies in agarose. Most lymphoma lines formed colonies in agarose and tumors in the mice. One of the two myeloma lines formed subcutaneous tumor which, however, showed no progressive growth. The other myeloma line failed to grow. Both myeloma lines, however, formed colonies in agarose. The myeloid leukemia line was tumorigenic while two of the three tested lymphocytic leukemia lines failed to grow in the mice. All leukemia lines formed colonies in agarose. We conclude from this study that: (1) Of the two types of Epstein-Barr virus containing cell lines [LCL and Burkitt lymphoma (BL) lines], only BL lines were shown to form tumors when inoculated subcutaneously in nude mice and had the capacity to grow in agarose in vitro. This shows that EBV transformation per se does not necessarily render lymphocytes tumorigenic in nude mice. The capacity to form colonies in agarose is not acquired either. (2) Changes of the karyotype and several phenotypic characteristics which occur in the originally diploid LCL during prolonged cultivation in vitro may be accompanied by the acquisition of the potential to grow subcutaneously in nude mice and in agarose in vitro. (3) The inconsistency with regard to the capacity of come of the neoplastic cell lines to grow in nude mice or in agarose seems to underline that neither of the two tests is a reliable criterion for malignancy of human lymphoma, leukemia and myeloma cell lines.
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PMID:Tumorigenicity of human hematopoietic cell lines in athymic nude mice. 1 96

A panel of established cell lines and many primary cell specimens from lymphomas and leukemias as well as from normal lymphatic tissues were tested for tumorigenicity by intracranial heterotransplantation in nude mice. Not only lymphoma and leukemia cell lines, but also lymphoblastoid cell lines, lacking markers of malignancy, were tumorigenic in the brains of nude mice. These findings indicate that tumorigenicity following intracranial heterotransplantation in nude mice cannot be used as proof for the malignant nature of established cell lines. Heterotraplantation of primary cell specimens yielded only a few tumor takes. When primary cells were infected with exogenous Epstein-Barr virus prior to the transplantation procedure, tumorigenicity could be significantly increased. Cytogenetic evaluation of tumors growing after intracranial transplantation of human hematopoietic cells showed, in some cases, a selection of cytogenetically aberrant cell clones.
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PMID:Intracranial heterotransplantation of human hematopoietic cells in nude mice. 3 11

Low antigen concentrations could be identified in human cells by sequential application of (a) FITC-labeled human antibodies at high dilution, (b) rabbit antiserum to the hapten fluorescein isothiocyanate (FITC), and (c) FITC-anti-rabbit globulin. The high specificity of direct immunofluorescence (a) was not affected by the amplifying steps (b) and (c). Using this AMDI technique Epstein-Barr (EB) virus nuclear antigen (EBNA) could be specifically stained with human sera up to a dilution of 1 : 4000. Owing to the high dilutions applied, unwanted antibody reactivity in the FITC-labeled serum could be blocked by preincubating with unlabeled undiluted human sera. Thus EBNA was selectively stained in EB virus producer cells. Moreover, EBNA was specifically detected in human tumor biopsy material by the use of AMDI.
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PMID:Amplified direct immunofluorescence (AMDI) for detection of Epstein-Barr virus nuclear antigen. 8 87

Cells of the human lymphoblastoid non-producer line Raji were cloned in soft agar. Individual colonies were isolated and analyzed for their inducibility of the Epstein-Barr virus-associated early antigen (EA). The induction of EA by the tumor promoter TPA varied among the different cell clones. Clones with very high and very low inducibility of the resident Epstein-Barr virus genome were further analyzed. Constant differences in the inducibility of EA were observed after activation by tumor promoters, 5-iododeoxyuridine or antibodies to human IgM. Induction of EA synthesis by superinfection with Epstein-Barr virus from the P3HR-1 line, however, did not vary among the clones tested. No differences in expression of the Epstein-Barr virus-associated nuclear antigen (EBNA) were noted in cells of clones with high or low susceptibility to EA induction. DNA reassociation kinetics demonstrated that Raji cells with high susceptibility to EA induction contained a significantly higher number of Epstein-Barr virus genome equivalents per cell than cells with low susceptibility. Treatment of Raji cells with the tumor promoter TPA did not change the ratio of Epstein-Barr virus-specific DNA to cellular DNA.
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PMID:Differential inducibility of Epstein-Barr virus in cloned, non-producer Raji cells. 8

81 untreated malignant lymphomas of the neck were classified morphologically according to the German Kiel classification and to the American classification of Rappaport and Berard and these tumors were typed immunologically as to their T- or B-cell nature. Cells from 16 of these patients were subsequently grown in tissue culture for periods up to seven months. Tissue culture cells were monitored as to spontaneous variations in the morphologic cell type and to the expression of T- or B-cell surface determinants. In addition in 10 patients sera were tested for anti-Epstein-Barr virus (EBV) antibodies. The results of these investigations were correlated with the course of the individual neoplastic disease. Significantly elevated titers against EBV antigens were detected primarily in 8 of 10 patients, mainly in lymphocytic lymphomas respective lymphoplasmacytoid immunocytomas. All such neoplasms belonged immunologically to B-cell lymphomas and were readily grown in tissue culture. The morphological cell type and the expression of B-cell determinants showed some variation during the culture period. In contrast,lymphomas of EBV-negative patients or patients with low EBV-titers grew poorly in tissue culture and remained morphologically more stabile. Immunocytologically they belonged to tumors with B- and T-cell deficiency and were classified primarily as histiocytic lymphomas and as Hodgkin's lymphomas. The clinical course in slow proliferating tumors seemed to be rather disadvantageous.
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PMID:[Classification of malignant lymphomas of the neck: combined morphological, immunocytological, serological and tissues culture studies (author's transl)]. 13 61

This study describes the establishment of three non-Burkitt B-lymphoma cell lines (BALM-3, BALM-4 and BALM-5) originating from the pleural effusion of a patient with a poorly differentiated diffuse lymphocytic lymphoma. The cells of BALM-3, -4 and -5 exhibited a number of properties which distinguish them from the usual B-cell type lymphoblastoid cell lines. Thus, they lacked the Epstein-Barr virus genome and had abnormal chromosome constitutions including a 14q+ marker. The presence of the identical surface immunoglobulin isotypes (gamma and chi chain determinants), and Ia-like B-cell-associated antigen in the cultured cells and in the "fresh" lymphoma cells in vivo was demonstrated. These findings strongly suggested that these cell lines have B-cell characteristics and were derived from the original tumor cell population. BALM-5 cells, however, showed somewhat different growth, cell surface marker profile and functional characteristics compared to those of BALM-3, and -4 cells. These variations suggest that the BALM-5 cells were probably at different stages of B-cell maturation than those of BALM-3 and -4, even though all three cell lines (established in three separate flasks) originated from the cells of the same pleural effusion of a lymphoma with monoclonal B-cell characteristics.
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PMID:Establishment and characterization of human B-lymphocytic lymphoma cell lines (BALM-3, -4 and -5); intraclonal variation in the B-cell differentiation stage. 16 Aug 94

Two cases of lymphoma and one case of lymphoproliferative disease were found in a group of 7 owl monkeys imported into our colony as a single group. Herpesvirus saimiri (HVS) was isolated from the tumor cells of 1 lymphoma by cocultivation and from kidney cell cultures from the monkey with lymphoproliferative disease. Antibody to HVS was found in serum samples from 2 monkeys positive for HVS but not in the sera from the 4 clinically normal monkeys. Antibody to Epstein-Barr virus-infected cells was also found in the serum from the animal with lymphoma.
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PMID:Spontaneous lymphoma associated with Herpesvirus saimiri in owl monkeys. 16 36

Fourteen tumors of the nasopharyngeal region were analyzed for the presence of Epstein-Barr virus-specific DNA by DNA-cRNA hybridization. These data were compared to the histology of the respective tumors and the seroreactivity of the tumor-bearing patient against EBV-related antigens. With one exception, all tumor pieces containing nasopharyngeal carcinoma cells hybridized significantly with EBV-cRNA. Tumors of predominantly epithelial morphology annealed in the highest range. In situ-hybridization of freeze sections from a tumor containing almost equal amounts of tumor cells and lymphocytes revealed hybridizing DNA within nuclei of non-lymphoid cells. Although these data do not exclude the presence of EBV-DNA within lymphoid cells, they clearly demonstrate that in nasopharyngeal carcinomas the vast majority of EBV-specific DNA rests within non-lymphoid cells.
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PMID:Attempts to detect virus-specific DNA sequences in human tumors. III. Epstein-Barr viral DNA in non-lymphoid nasopharyngeal carcinoma cells. 16 92

Relationships between the rate of DNA synthesis in cultured human umbilical cord leukocytes and the multiplicity of added Epstein-Barr virus (EBV) were studied. At low multiplicities of approximately 0.1 transforming units/cell (approximately 10 physical particles/cell), inoculated cultures demonstrated increased rates of DNA synthesis, by comparison to uninoculated cultures, 3 days after inoculation. Stimulation of DNA synthesis was evident of progressively longer intervals after inoculations of 10-fold dilutions of virus. The rate of DNA synthesis, determined by short [-3H]thymidine pulses, reflected as small as twofold changes in multiplicity and thus can serve as a quantitative assay for the virus. Changes in the rate of DNA synthesis were evident before increases in cell number or alteration in morphology. Stimulation of DNA synthesis in umbilical cord leukocytes was inhibited by treatment of EBV with antibody and also in graded fashion, by progressive doses of UV irradiation to the virus. Induction of DNA synthesis by EBV was serum dependent. Estimates of the number of cells transformed were obtained by extrapolation from a standard curve relating known numbers of transformed cells to [-3H]thymidine incorporation and also by cloning cells after exposure to virus. At the low multiplicities of infection used in these experiments approximately 0.04 to 0.002 of the total cellular population was transformed. The high efficiency of cell transformation by EBV by comparison to other DNA tumor viruses is emphasized.
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PMID:Assay for Epstein-Barr virus based on stimulation of DNA synthesis in mixed leukocytes from human umbilical cord blood. 16 82

Humoral antibodies can be induced in cotton topped (CT) marmosets with killed Herpesvirus saimiri (HVS) vaccines. The serum antibodies delayed, but did not prevent, malignant lymphoma in actively and passively immunized monkeys after inoculation with 10(3.8)TCID50 of cell-free HVS. Experiments are in progress to determine whether the vaccines are able to protect against smaller challenge dosages of HVS. The immunized monkeys were not resistant against transplantation of tumor cells. Infection with Epstein-Barr virus (EBV) and Marek's disease virus (MDV) did not protect against the tumors caused by superinfection with HVS. Attenuation of HVS was not achieved by passaging the HVS genome through different monkey species.
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PMID:Experiments to vaccinate marmoset monkeys against malignant lymphoma. 16 14


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