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

The SK-Luci-6 cell line, established from a large-cell anaplastic lung tumor of a patient with humoral hypercalcemia of malignancy (HHM), was investigated to identify osteolytic factors produced that might mediate HHM. Most HHM-associated tumors are thought to produce parathyroid hormone-related proteins or transforming growth factor (TGF) alpha. SK-Luci-6 cells formed s.c. tumors and induced hypercalcemia in athymic nude mice. Serum-free conditioned medium from SK-Luci-6 cultures induced bone resorption in neonatal mouse calvariae in vitro, and also contained TGF-beta activity and mitogenic activity. SK-Luci-6 cell conditioned medium did not displace [125I]epidermal growth factor binding to cell receptors or stimulate cyclic AMP formation in rat osteosarcoma cells, suggesting that the conditioned medium did not contain TGF-alpha or parathyroid hormone-related proteins. The osteolytic, TGF-beta, and mitogenic activities copurified in several chromatographic separations: gel filtration in acid and then in guanidine HCl; ion exchange; and reverse phase. The results suggest that in the HHM-associated SK-Luci-6 tumor, the causative osteolytic factor produced by the tumor cells is not a parathyroid hormone-related protein or TGF-alpha but, rather, may be a TGF-beta.
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PMID:Copurification of osteolytic and transforming growth factor beta activities produced by human lung tumor cells associated with humoral hypercalcemia of malignancy. 253 57

The osteogenic factor from murine osteosarcoma was soluble in 4M guanidine-HCl. The precipitate that appeared after dialysis of the guanidine solution against deionized water showed a higher osteogenetic activity than did the initial dry powder of tumor tissue. Electron-microscopically, this bone-inducing fraction seems to be homogenous. Neither a fibrous nor collagenous cross-banded structure was observed in the fraction. Since the chemical analysis of the fraction also showed a relatively low content of hydroxyproline, the osteogenic factor is probably not collagen.
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PMID:Solubilization and concentration of a bone-inducing substance from a murine osteosarcoma. 676 29

A selection of proteins including bone morphogenetic protein (BMP) was extracted in a disaggregated form from Dunn osteosarcoma or rat demineralized bone matrix by 4M guanidine hydrochloride (GuHCl) solution without losing its biological activity. The GuHCl extracts of Dunn osteosarcoma were divied into 4 different fractions by cesium chloride (CsCl) density gradients. Under a dissociative condition, the highest new bone yield was obtained in the low dense top one-third fraction, and BMP acitivity declined with increase in the density of each fraction. No BMP potential was observed in the surface-gel fraction under dissociative conditions. Under an associative condition (low GuHCl concentrations), BMP activity appears in the surface-gel fraction, while under a dissociative condition (high concentrations of GuHCl) BMP appears in the fraction below the surface gel. These facts suggest that under associative conditions, BMP aggregates with other low dense proteins in the surface-gel fraction and that this may be the state of aggregation of BMP in cells and matrix in nature. Present observations support the assumption that BMP is a relatively low density protein and excludes the idea of BMP activity in the collagen molecule, per se. A specific protein, with an apparent molecular weight of 63,000 daltons, is present in all fractions that exhibit BMP activity, and absent in fractions that do not exhibit this activity. BMP is not species-specific; rat BMP induces bone formation in mice. CsCl density-gradient centrifugation is an efficient tool for further purification and isolation of BMP.
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PMID:Solubilized bone morphogenetic protein (BMP) from mouse osteosarcoma and rat demineralized bone matrix. 692 47

A bone morphogenetic protein (BMP) fraction obtained from the organic matrix of dentin is extractable from human osteosarcoma. A fresh en-bloc specimen excised from the femur of a 16-year-old boy was extracted with 4 M guanidine hydrochloride. The GuHCl-soluble, water-insoluble protein fraction induced new bone formation when implanted into the thigh muscles of athymic nude mice.
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PMID:Human osteosarcoma-derived soluble bone morphogenetic protein. 693 75

Devitalized cultured cells of a murine osteosarcoma preserved strong osteogenic activity even after incubation in neutral and acidic buffer at 37 degrees for six days. This observation suggested that an osteosarcoma-derived osteogenic factor was considerably stable to endogenous proteases, or that osteosarcomas do not synthesize enzymes for degradation of the osteogenic factor. EDTA decalcification or extraction of the osteosarcoma at 37 degrees for six days had no apparent effect on the osteogenic factor. Disulfide-bond reducing agents (2-mercaptoethanol and dithiothreitol) completely inactivated the osteogenic activity and in the presence of guanidine HCl, the loss of activity was irreversible by reoxidation. There findings support the view that disulfide-bonds in the molecular structure of the osteogenic factor are essential for the biological activity.
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PMID:Biochemical stability of a bone-inducing substance from murine osteosarcoma. 695 Aug 22

The resistance of cartilage to tumor invasion was studied with the use of a novel in vitro culture system. Articular cartilage obtained from fresh metacarpophalangeal joints of preadolescent bovines was used as a growth surface for human TE-85 osteosarcoma cells and foreskin fibroblasts. Cartilage disks formed the bottoms of stainless-steel cylinders, providing closed growth chambers for these cells. Both invasive osteosarcoma cells and normal fibroblasts were unable to penetrate viable, unextracted cartilage during a 2-week culture period. When cartilage was devitalized by freezing and thawing, the tissue remained resistant to invasion. Cartilage, extracted with either 1 or 3 M guanidine hydrochloride, was invaded by osteosarcoma cells, but not by control fibroblasts. Invasion by osteosarcoma cells into salt-extracted cartilage was abolished when low concentrations of a cartilage-derived, anti-invasion factor were added to the culture medium. These data provided evidence that the resistance of cartilage to tumor invasion is regulated in part by tissue-derived proteinase inhibitors.
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PMID:Regulation of tumor invasion by cartilage-derived anti-invasion factor in vitro. 701 30

It is well known that the bone matrix contains proteins which can induce ectopic endochondral bone formation in vivo. One class of these proteins is the bone morphogenetic protein (BMP). In order to investigate the physiological function of the BMP, its purification was attempted from an extract of demineralized bone matrix and its actions on the osteoblastic cell line were investigated. To isolate the BMP, a demineralized bone matrix was extracted with 4M guanidine-HCl. A water-insoluble fraction (G-WI) was separated from the demineralized bone extract by dialysis against distilled water and centrifugation. The BMP was purified from G-WI by gel filtration on Sephacryl S-200 HR, cation exchange with Mono-S, heparin affinity column and finally by C1/8 reverse phase chromatography. Peptide sequence analysis revealed that the purified BMP fraction contained "BMP-3" reported by Wozney et al. (1988). In order to investigate its function, the BMP was applied to the rat osteogenic sarcoma cell line UMR108. The BMP inhibited the growth of the UMR108 cells and enhanced the alkaline phosphatase activity in a dose-responsive manner.
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PMID:[Purification of bone morphogenetic protein and investigation of its effects on osteoblastic cell line UMR108]. 848 1

Cell-fibronectin interactions, mediated through several different receptors, have been implicated in a wide variety of cellular properties. Among the cell surface receptors for fibronectin, integrins are the best characterized, particularly the prototype alpha5beta1 integrin. Using [125I]iodine cell surface labeling or metabolic radiolabeling with sodium [35S]sulfate, we identified alpha5beta1 integrin as the only sulfated integrin among beta1 integrin heterodimers expressed by the human melanoma cell line Mel-85. This facultative sulfation was confirmed not only by immunoprecipitation reactions using specific monoclonal antibodies but also by fibronectin affinity chromatography, two-dimensional electrophoresis, and chemical reduction. The covalent nature of alpha5beta1 integrin sulfation was evidenced by its resistance to treatments with high ionic, chaotrophic, and denaturing agents such as 4 M NaCl, 4 M MgCl2, 8 M urea, and 6 M guanidine HCl. Based on deglycosylation procedures as chemical beta-elimination, proteinase K digestion, and susceptibility to glycosaminoglycan lyases (chondroitinase ABC and heparitinases I and II), it was demonstrated that the alpha5beta1 heterodimer and alpha5 and beta1 integrin subunits were proteoglycans. The importance of alpha5beta1 sulfation was strengthened by the finding that this molecule is also sulfated in MG-63 (human osteosarcoma) and HCT-8 (human colon adenocarcinoma) cells.
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PMID:Post-translational modifications of alpha5beta1 integrin by glycosaminoglycan chains. The alpha5beta1 integrin is a facultative proteoglycan. 913 4

The transducing ability of the third helix of transcription factor homeodomains is effectively mimicked by a biphenyl system displaying guanidine groups. The biphenyl class of small molecule carriers (SMoCs) can carry biomolecules into a wide variety of cell types. A "combinatorial" approach to the synthesis of SMoCs is described using sequential Pd(0) coupling chemistry to assemble the molecules from highly functionalized building blocks. SMoCs coupled to the DNA licensing repressor protein geminin can inhibit DNA replication in vitro. We conducted a structure-activity investigation utilizing a range of SMoC-geminin conjugates and demonstrate that both electrostatic and structural features are important for efficient uptake and functional activity. The best analogue was more efficient than either (Arg)(4) or (Arg)(8) linked to geminin. Effective inhibition of DNA synthesis was achieved in fibroblasts and osteosarcoma cell lines.
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PMID:Modular assembly using sequential palladium coupling gives easy access to the SMoC class of cellular transporters. 1860 31


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