phosphorus-radioisotopes and Burkitt-Lymphoma

The vav proto-oncogene product (p95vav) is specifically expressed in cells of the hematopoietic system, contains one Src homology 2 and two Src homology 3 domains, and is a substrate for receptor and non-receptor tyrosine kinases. Immunoblotting experiments using an anti-phosphotyrosine monoclonal antibody showed that interferon alpha (IFN alpha) induces rapid tyrosine phosphorylation of p95vav after binding to its cell surface receptor in the U-266 human myeloma cell line. The IFN alpha-induced tyrosine phosphorylation of p95vav was time- and dose-dependent, confirming the specificity of the process. IFN alpha-dependent tyrosine phosphorylation of p95vav was also observed in other hematopoietic cell lines of B-cell origin (Daudi), T-cell origin (MOLT-4), and promyelocytic origin (HL-60). Immunoprecipitation experiments performed with 32P-labeled U-266 cells and phosphoaminoacid analysis of the bands corresponding to p95vav showed that p95vav is phosphorylated on serine residues prior to IFN alpha stimulation of the cells. After IFN alpha stimulation significant amounts of phosphorylation of p95vav on tyrosine residues were detectable. Tyrosine phosphorylation of p95vav in U-266 and HL-60 cells was also induced by two other Type I IFNs, IFN beta and IFN omega. Altogether these data suggest that the vav proto-oncogene product is a substrate for a Type I IFN-regulated tyrosine kinase(s) and may be involved in the signal transduction pathway of Type I IFNs in hematopoietic cells.

Topics: Burkitt Lymphoma; Cell Cycle Proteins; Cell Line; Hematopoiesis; Humans; Interferon Type I; Interferon-beta; Leukemia-Lymphoma, Adult T-Cell; Leukemia, Promyelocytic, Acute; Multiple Myeloma; Phosphorus Radioisotopes; Phosphotyrosine; Proto-Oncogene Mas; Proto-Oncogene Proteins; Proto-Oncogene Proteins c-vav; Proto-Oncogenes; Recombinant Proteins; Tumor Cells, Cultured; Tyrosine

Topics: Beta Particles; Burkitt Lymphoma; Cell Death; Cell Line; Humans; Phosphorus Radioisotopes

Topics: Adolescent; Adult; Aged; Antibodies, Viral; Antigens, Viral; Biopsy; Burkitt Lymphoma; Cell Survival; Child; Child, Preschool; Chromatography, Gel; DNA, Viral; Female; Herpesvirus 4, Human; Hodgkin Disease; Humans; Leukemia, Lymphoid; Lymphoma, Non-Hodgkin; Male; Middle Aged; Nucleic Acid Hybridization; Phosphorus Radioisotopes; Staining and Labeling

Topics: Base Sequence; Burkitt Lymphoma; Cell Line; Cells, Cultured; Centrifugation, Density Gradient; Chromatography, DEAE-Cellulose; Genes; Humans; Lectins; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Lymphocyte Activation; Lymphocytes; Oligonucleotides; Pancreas; Phosphorus Radioisotopes; Purines; Remission, Spontaneous; Ribonucleases; RNA, Ribosomal

High-molecular-weight DNA from cell line Raji (derived from Burkitt's lymphoma), which contains 50-60 copies of Epstein-Barr virus DNA per cell, was fractionated in neutral solution by several cycles of CsCl gradient centrifugation in fixed-angle rotors. Under the fractionation conditions used, intact Epstein-Barr virus DNA from virus particles can be separated from the less-dense cellular DNA. In contrast, a large proportion of the intrinsic Epstein-Barr virus DNA component of Raji cells remains associated with cellular DNA, as determined by nucleic acid hybridization. This interaction, which is resistant to Pronase and phenol treatment, is not the result of aggregation. When the molecular weight of Raji DNA is reduced by hydrodynamic shear, the amount of virus DNA associated with cell DNA decreases. However, some virus DNA still remains bound to fragments of cellular DNA after shearing. The association is completely destroyed in alkaline solution. Molecular weight analysis of Raji DNA after denaturation showed that the alkali-induced release of Epstein-Barr virus DNA was specific and not the result of random single-strand breaks. These data indicate that Epstein-Barr virus DNA is linearly integrated into Raji cell DNA by alkali-labile bonds.

Topics: Burkitt Lymphoma; Carbon Radioisotopes; Cell Line; Centrifugation, Density Gradient; DNA, Bacterial; DNA, Neoplasm; DNA, Viral; Herpesvirus 4, Human; Humans; Hydrolysis; Molecular Weight; Nucleic Acid Denaturation; Nucleic Acid Hybridization; Phosphorus Radioisotopes; Pronase; RNA, Viral; Tritium

Topics: Burkitt Lymphoma; Cell Division; Cell Nucleus; Cells, Cultured; Electrophoresis, Polyacrylamide Gel; Humans; Lectins; Leukemia; Leukemia, Lymphoid; Leukocytes; Lymphocyte Activation; Lymphocytes; Molecular Weight; Peptide Hydrolases; Phosphoric Monoester Hydrolases; Phosphorus Radioisotopes; Proteins; Sodium Dodecyl Sulfate; Tritium

Topics: Burkitt Lymphoma; Cell Nucleus; Centrifugation, Density Gradient; Humans; Leukemia; Leukemia, Lymphoid; Leukemia, Myeloid, Acute; Lymphoma, Non-Hodgkin; Phosphorus Radioisotopes; RNA, Neoplasm; Sucrose