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)

The bone inducing factor derived from BF osteosarcoma was purified in the following manner. Step 1. The sarcoma, grown in CBA mice, was excised and lyophilized. Step 2. The powder was washed with chilled acetone. Step 3. The acetone-treated powder was then homogenized with chilled distilled water. Step 4. Washing with 0.15M KCl. Step 5. The precipitate was incubated in in 0.2 N NH2OH, pH7.0, for 48 H at 25 degrees. After Step 5, the bone-forming activity showed a slight increase; however, the factor remained insoluble. The properties of the factor were as follows. The factor is relatively relatively heat stable; the osteogenic activity survived the treatment at 75 degrees for 15 min or at 55 degrees for 19 h. The activity was easily lost by mechanical shaking. Incubation with DNase, RNase, neuraminidase, chondroitinase ABC and beta-galactosidase left the osteogenic activity intact, but treatment with either pronase or collagnease destroyed this activity. The results suggest that the factor may be a protein. The activity was seen with the lyophilized BF osteosarcoma cells (without matrix), and it is probable that the factor was exclusively synthesized in the cells. The bone formation, observed across a millipore filter when living BF osteosarcoma enclosed in a millipore chamber was implanted in mice, suggests the synthesis and secretion of the factor from the cells.
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PMID:Studies on a factor responsible for new bone formation from osteosarcoma in mice. 105 58

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

Several methods to alter cell surface glycosaminoglycan (GAG) expression have previously been described, including treatments with chlorate to reduce the addition of charged sulfate groups, xyloside compounds to displace GAGs from their core proteins, and GAG lyases, such as heparinase and chondroitinase, to release GAG fragments from the cell layer. While these methods are useful in identifying cellular mechanisms which are dependent on GAGs, they must be stringently validated to assess results in the appropriate context. To determine the most useful technique for the evaluation of GAG function in osteogenesis, MG-63 osteosarcoma cells were systematically treated with these agents and evaluated for changes in cell surface GAGs using a TAT-EGFP fusion protein. TAT, a protein transduction domain from the HIV-1 virus, requires cell surface GAGs to traverse cell membranes. The EGFP component provides a method to assess protein entry into cells in both qualitative and quantitative tests. Here, TAT-EGFP transduction analysis confirmed radiochemical and physiological data that chlorate effectively disrupts GAG expression. TAT-EGFP entry into cells was also inhibited by the exogenous application of commercial heparin and GAGs extracted from MG-63 cells as well as by the pre-treatment of cells with chondroitinase ABC. However, neither heparinase III treatment nor the addition of exogenous chondroitin-6-sulfate affected TAT-EGFP entry into cells. In addition, xyloside-beta-D-naphthol and xyloside-beta-D-cis/trans-decahydro-2-naphthol treatment could not induce significant phenotypic change in these cells, and the unaffected TAT-EGFP transduction confirmed that this was due to an inability to efficiently prime GAG synthesis. The use of TAT-EGFP is thus a useful technique to specifically evaluate cell surface GAG expression in a simple, quantifiable manner, and avoids the complications involved with conventional radiochemical assays or analytical chromatography.
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PMID:A novel use of TAT-EGFP to validate techniques to alter osteosarcoma cell surface glycosaminoglycan expression. 1788 14