Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Anti-peptide and anti-protein antisera were produced which both recognize bone acidic glycoprotein-75 (Mr = 75,000) and an apparent fragment or biosynthetic intermediate (Mr = 50,000) in calcified tissues and/or serum. A fragment-precursor relationship is suggested from the fact that closely spaced doublet polypeptides of Mr = 50,000 could be produced by proteolysis of the purified protein upon long term storage. No reactivity was detected with osteopontin, bone sialoprotein, or small bone proteoglycans. Bone acidic glycoprotein-75 represents 0.5-1% of the total radiolabeled proteins synthesized by explant cultures of neonatal calvaria or growth plate, by calvarial outgrowth cultures, and by rat osteosarcoma cells. Amounts produced by explant cultures and calvarial outgrowth cultures were similar to that for osteopontin, a major product of osteoblasts. In osteosarcoma cultures, 80% of labeled antigens were associated with the cell layer fraction wherein specific immunoprecipitation pelleted Mr = 50,000 and 75,000 sized antigens. Bone acidic glycoprotein-75 (Mr = 75,000) is enriched in 4 M guanidine HCl/0.5 EDTA extracts of neonatal rat bone and growth plate tissues, whereas largely absent from heart, lung, spleen, liver, brain, and kidney. Explant cultures of these noncalcifying tissues also synthesized bone acidic glycoprotein-75 antigen, but the quantities produced were only 5% or less that obtained with calvaria. By immunohistochemistry, antigenicity is associated with the bony shaft and calcified cartilage of long bones, but is absent from associated soft tissues. These finding demonstrate that bone acidic glycoprotein-75 is antigenically distinct, predominantly localized to calcified tissues, represents a major product of normal osteoblastic cells and may undergo a characteristic fragmentation in vivo and in vitro.
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PMID:Bone acidic glycoprotein-75 is a major synthetic product of osteoblastic cells and localized as 75- and/or 50-kDa forms in mineralized phases of bone and growth plate and in serum. 239 8

Multilayered coatings composed of mixtures of hydroxyapatite (HA) and P(2)O(5)-based bioactive glasses offer potential clinical benefits in orthopedic and dental surgery. In this study double-layer plasma-sprayed coatings were prepared and the biological response evaluated in tissue culture using two human osteosarcoma cell lines, MG63 and HOS TE85 (HOS). The cells were cultured on the materials and the effects on cell growth were determined using a spectrophometric assay of a mitochondrial enzyme that is active in viable cells. While none of the materials influenced the growth of the MG63 cells, the HOS cells appeared to undergo less proliferation on all the HA materials. Flow cytometry analysis was carried out using rabbit antibodies against osteonectin, osteopontin, bone sialoprotein, fibronectin, and collagen type I to measure the effects of the materials on key cellular functions. The results showed that the materials downregulated the expression of these extracellular matrix antigens by MG63 cells whereas they had less effect on the HOS cells compared to the same cells incubated on a plastic surface. Notably, with both cell lines the composite with the higher percentage of glass restored the production of connective tissue proteins to levels that were more similar to those present in the control cells.
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PMID:Flow cytometry analysis of effects of glass on response of osteosarcoma cells to plasma-sprayed hydroxyapatite/CaO-P(2)O(5) coatings. 1049 97

The expression of osteonectin, osteopontin, bone sialoprotein, and osteocalcin was evaluated by immunohistochemistry in 57 cases of osteoid-forming and non-osteoid-forming bone tumours using specific polyclonal antibodies and the avidin-biotin peroxidase complex method. A positive immunostaining was found in all of the osteoid-forming rumours (osteoblastoma and osteosarcoma), both in the cells and in the extracellular matrix. Among non-osteoid-forming tumours, immunoreactivity to noncollagenous proteins was present in the cells but not in the matrix of chondrosarcoma, malignant fibrous histiocytoma, and fibrosarcoma, as well as in the mononuclear component of giant-cell rumours. Contrary to small-cell osteosarcoma, Ewing's sarcoma was always negative for all of the noncollagenous proteins considered. These results suggest that the immunohistochemical evaluation of noncollagenous proteins of bone may be a useful tool for the differential diagnosis of bone neoplasms, particularly among the heterogeneous group of small round cell tumours.
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PMID:Value of immunohistochemical detection of noncollagenous proteins of bone for the diagnosis of bone tumours. 2154 9