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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The transforming gene of the osteosarcoma-producing FBJ murine sarcoma virus, v-fos, is homologous to a normal cellular gene, c-fos, in vertebrate species. Transcripts from the c-fos proto-oncogene accumulate to very high levels in late gestational mouse and human extra-embryonic tissues. We now report that these RNA transcripts are translated in these tissues. Rabbits were immunized with a synthetic peptide whose sequence is common to both c-fos and v-fos. After affinity purification on an immunosorbent containing the fos peptide (a nonapeptide), the antibody reacted with a component(s) in nuclei in sections of human and murine tissues and immunoprecipitated the v-fos gene product (p55) and a cellular protein of 39 kd (p39, complexed with fos) from lysates of metabolically-labelled virally transformed cells. Crude extracts of normal tissues contained major anti-fos-reactive proteins in the range of 55-60 kd as shown by protein blot analysis. Indirect immunofluorescence and immunoperoxidase staining showed that in addition to strong immunoreactive component(s) in the nuclei of extra-embryonic tissues of human and mouse, weaker reactions are detectable in all normal fetal and adult tissues tested. This demonstrates that fos-reactive protein is expressed in a wide variety of cells and tissues.
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PMID:Product of the cellular oncogene, c-fos, observed in mouse and human tissues using an antibody to a synthetic peptide. 389 12

The FBR murine osteosarcoma virus complex induces bone tumors with a similar latency and pathology to those induced by the FBJ virus complex. FBR murine sarcoma virus ( FBR -MSV) has been isolated from its helper virus(es) by the establishment of transformed nonproducer cells. These cells were found to express a 75,000-Da protein (P75) which was antigenically related to the p55 oncogene product of the FBJ murine osteosarcoma virus ( FBJ -MSV). P75 also contained antigenic determinants of murine leukemia virus (MLV) gag gene p15, p12, and p30 proteins, and is therefore a gag- fos fusion protein ( P75gag - fos ). P75gag - fos is a phosphoprotein and is found primarily in the nucleus. Only a single species of RNA, of 3.3 kb, was identified in FBR -MSV-transformed nonproducer cells using both fos and MLV probes, which suggested that P75gag - fos was expressed from genome-sized RNA. Chromosomal DNA from one nonproducer cell line was found to contain a single EcoRI restriction fragment of 12 kb pairs (kbp) which encompassed the FBR -MSV provirus. This DNA fragment was molecularly cloned into bacteriophage Charon 30 (lambda FBR -1), and a 7.5-kbp HindIII restriction fragment containing the entire provirus was subsequently subcloned into pBR322 ( pFBR -1). DNA from pFBR -1 was capable of inducing morphological transformation of mouse and rat fibroblasts in tissue culture. In addition, transfected cells expressed the FBR -MSV P75gag - fos protein.
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PMID:FBR murine osteosarcoma virus. I. Molecular analysis and characterization of a 75,000-Da gag-fos fusion product. 620 14

A 12.0-kilobase EcoRI restriction fragment containing FBJ murine osteosarcoma virus (FBJ-MSV) proviral DNA was identified in FBJ-MSV-transformed nonproducer rat cells and molecularly cloned in bacteriophage Charon 30 (lambda FBJ-1). A 5.8-kb HindIII fragment containing the entire FBJ-MSV proviral DNA was isolated from lambda FBJ-1 and subsequently subcloned in plasmid pBR322 (pFBJ-2). The DNA from recombinant plasmid pFBJ-2 was able to induce morphological transformation of rat fibroblasts in tissue culture. Transfected cells contained the p55 and p39 antigens specific for cells transformed by FBJ-MSV (T. Curran and N. M. Teich, J. Virol. 42:114-122, 1982). The organization of the FBJ-MSV provirus was analyzed by restriction endonuclease mapping, and a region of nonhomology with the helper virus was delineated. Sequences specific for this region (presumably the viral fos gene) were subcloned and used as a probe to identify related sequences present in the normal genomes of cells from a variety of mammalian species (cellular fos). A single-size (3.4 kilobases long) class of RNA hybridizing to the viral fos probe was identified in FBJ-MSV-transformed cells.
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PMID:FBJ murine osteosarcoma virus: identification and molecular cloning of biologically active proviral DNA. 629 25

The protein predicted from the DNA sequence of the FBJ murine osteosarcoma virus (FBJ-MSV) onc gene (v-fos) was expressed in Escherichia coli under the control of the tryptophan operon regulatory region. The 381-amino acid protein was identified by synthesis in minicells isolated from bacteria containing the expression vector plasmid. A 52,000-Da protein was made in these minicells, along with the proteins encoded by the beta-lactamase gene present on the expression vector plasmid. Synthesis of the 52K protein was repressed in trpR+ E. coli minicells in the presence of tryptophan, whereas the protein was synthesized under the same conditions in trpR- (derepressed) minicells. The beta-lactamase proteins, however, were synthesized under both conditions. The synthesis of the viral protein, therefore, was directed by the trp operon promoter. The tryptic peptide map of the 52K bacterial protein labeled with [35S]methionine was compared to that of the 35S-labeled protein immunoprecipitated from FBJ-MSV transformed rat cells using tumor-bearing rat sera. The peptide map of the p55 protein, previously identified as a candidate transforming protein in FBJ-MSV transformed cells, matches exactly that of the bacterial 52K protein. The eukaryotic cell protein, however, differs slightly in electrophoretic mobility in SDS gels, most likely due to post-translational modification which does not occur in bacteria.
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PMID:Expression of FBJ-MSV oncogene (fos) product in bacteria. 631 37

A novel human mRNA whose expression is induced over 200-fold in B lymphocytes by latent Epstein-Barr virus (EBV) infection was reverse transcribed, cloned, and sequenced. The mRNA is predicted to encode a protein containing four peptides which precisely match amino acid sequences from a previously identified 55-kDa actin-bundling protein, p55. In vitro translation of the cDNA results in a 55-kDa protein which binds to actin filaments in the presence of purified p55 from HeLa cells. The p55 mRNA is undetectable in non-EBV-infected B- and T-cell lines or in a myelomonocytic cell line (U937). Newly infected primary human B lymphocytes, EBV-transformed B-cell lines, latently infected Burkitt tumor cells expressing EBNA2 and LMP1, a chronic myelogenous leukemia cell line (K562), and an osteosarcoma cell line (TK143) contain high levels of p55 mRNA or protein. In EBV-transformed B cells, p55 localizes to perinuclear cytoplasm and to cell surface processes that resemble filopodia. The p55 mRNA is detected at high levels in spleen and brain tissues, at moderate levels in lung and placenta tissues, and at low levels in skeletal muscle, liver, and tonsil tissues and is undetectable in heart, kidney, pancreas, and bone marrow tissues. Immunohistochemical staining of human brain tissue demonstrates p55 localization to the perinuclear cytoplasm and dendritic processes of many, but not all, types of cortical or cerebellar neurons, to glial cells, and to capillary endothelial cells. In cultured primary rat neurons, p55 is distributed throughout the perinuclear cytoplasm and in subcortical filamentous structures of dendrites and growth cones. p55 is highly evolutionarily conserved since it shows 40% amino acid sequence identity to the Drosophila singed gene product and 37% identity to fascin, an echinoderm actin-bundling protein. The evolutionary conservation of p55 and its lack of extensive homology to other actin-binding proteins suggest that p55 has specific microfilament-associated functions in cells in which it is differentially expressed, including neural cells and EBV-transformed B lymphocytes.
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PMID:Epstein-Barr virus infection induces expression in B lymphocytes of a novel gene encoding an evolutionarily conserved 55-kilodalton actin-bundling protein. 793 16

We studied how tumor necrosis-factor (TNF)-family proteins interact with osteoblasts to resolve several controversial points. We measured expression of TNFs, TNF-receptors, and nonsignaling (decoy) TNF receptors in human osteoblasts derived from mesenchymal stem cells and in MG63 human osteosarcoma cells using unamplified mRNA screening, with secondary Western or PCR analysis where indicated, and studied the effects of TNFs on osteoblasts in cell culture. Expression of TNFs and receptors was similar in MG63 cells and osteoblasts. TNF-R1 (p55), TRAIL receptor 1 and 2 (DR4 and 5), and Fas were expressed; RANK was undetectable. TNF-family ligands RANKL, TRAIL, and TNFalpha were expressed, but mRNAs were typically at low levels relative to receptors, suggesting that osteoblastic TNF signals, including RANKL, require specific stimuli. Flow cytometry of MG63 cells confirmed TNFalpha receptors and identified subpopulations with high surface-bound TNFalpha. Decoy receptors expressed included a novel soluble form of TNFRSF25 (formerly DR3 or Apo3), implicated in rheumatoid-arthritis linkage studies, as well as osteoprotegerin, a well-characterized osteoblast protein that binds TRAIL and RANKL, and DcR2, which binds TRAIL. Osteoblast apoptosis was studied using terminal deoxynucleotidyl transferase labeling and annexin V binding. MG63 cells were resistant to apoptosis by exogenous TNFalpha except when grown in media promoting osteoblast-like growth or matrix nodules. However, in media supporting osteoblast-like phenotype, apoptosis was induced by anti-Fas or TNF, in contrast to other studies with human osteoblasts. TRAIL caused cell retraction, supporting functional TRAIL response in cell differentiation, but did not cause apoptosis. We conclude that human osteoblasts have functional receptors for FasL, TNFalpha, TRAIL, but not RANKL, and that osteoblasts are protected by multiple nonsignaling TNF receptors against destruction by TNF-family proteins under conditions favoring cell growth.
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PMID:Expression and function of TNF-family proteins and receptors in human osteoblasts. 1462 51