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

We have succeeded in transplanting human osteogenic sarcoma of the mandible into nude mice. As the transplanted tumor shows features of calcified chondrosarcoma, this tumor is thought to be an excellent model for study of the process of dystrophic endochondral calcification. Using this model, we studied relations between the expression of types I, II, and X collagen and chondrogenic differentiation of the transplanted tumor. Collagen distribution during the development and growth of the transplanted tumor was investigated by immunofluorescence with specific antibodies against type I, II or X collagen. Type X collagen was intensely stained in the mineralized region. Almost all tumor cells in this region were hypertrophic. Type II collagen was chiefly distributed in the unmineralized region where tumor cells showed chondrocytic or hypertrophic feature. These results indicate that the type of collagen changes from type II to type X in the hypertrophic region and the type X collagen may be synthesized by hypertrophic tumor cells. Type I collagen was localized in the marginal region of the tumor, though it disappeared in the mineralized region.
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PMID:Localization of types I, II, and X collagen in the transplanted tumor derived from human osteogenic sarcoma. 157 7

Collagen synthesis in rat osteosarcoma cell line 17/2 (ROS 17/2) was assessed by measuring the incorporation of [3H]proline into collagenase-digestible protein and the formation of [3H]hydroxyproline. PTH and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] inhibited collagen synthesis in ROS 17/2 cells in a time- and dose-dependent manner. PTH reduced collagen synthesis after a 3-h incubation, whereas the effect of 1,25-(OH)2D3 was somewhat slower. Maximal and half-maximal inhibition of collagen synthesis occurred at approximately 1 and 0.1 nM of each hormone, respectively. At confluency, ROS 17/2 cells synthesized 96% type I and 4% type III collagen. PTH reduced the synthesis of type I, but not type III, collagen. PTH and 1,25-(OH)2D3 also reduced procollagen mRNA levels, as determined by a dot blot hybridization assay. Thus, ROS 17/2 cells are a convenient model system for studying the hormonal regulation of collagen metabolism and gene expression in a cloned cell line with the osteoblastic phenotype.
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PMID:Hormonal regulation of collagen synthesis in a clonal rat osteosarcoma cell line. 302 31

Two 1,25-dihydroxyvitamin D3-controlled parameters in the osteoblastlike osteosarcoma cell line ROS 17/2, bone gamma-carboxyglutamic acid-containing protein (BGP) and collagen synthesis, were measured after pretreatments with either retinoic acid (RA), or triamcinolone acetate (TRM). RA and TRM both caused double the expected increase in BGP secretion at 16 hr after treatment with 1,25-dihydroxyvitamin D3. Triamcinolone acetate concentrations of 10(-8) and 10(-9) M or 10(-6) M retinoic acid were effective in enhancing the 1,25-dihydroxyvitamin D3 stimulation of BGP secretion. Treatment with RA or TRM alone did not stimulate BGP secretion. RA alone had no effect on BGP secretion, while TRM inhibited BGP secretion. Collagen synthesis is inhibited by 1,25-dihydroxyvitamin D3. Neither retinoic acid nor triamcinolone acetate enhanced the 1,25-dihydroxyvitamin D3-mediated inhibition of collagen synthesis. Retinoic acid by itself inhibited collagen synthesis but did not change the 1,25 dihydroxyvitamin D3-mediated inhibition of collagen synthesis. Triamcinolone acetate by itself or together with 1,25-dihydroxyvitamin D3 increased collagen synthesis. We conclude that, although both triamcinolone acetate and retinoic acid increase the 1,25-dihydroxyvitamin D3 stimulation of BGP secretion by ROS 17/2 cells, they have different effects on the regulation of collagen production. Thus, although both hormones increase the 1,25-dihydroxyvitamin D3 receptor concentration in these cells, their actions are not mediated solely by this mechanism.
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PMID:Retinoic acid and glucocorticoids enhance the effect of 1,25-dihydroxyvitamin D3 on bone gamma-carboxyglutamic acid protein synthesis by rat osteosarcoma cells. 348 2

A mouse fibrosarcoma and rat osteosarcoma were examined histologically and biochemically with regard to collagen content. The fibrosarcoma was composed of undifferentiated mesenchymal cells without distinct fibroblastic characteristics. Collagen production and deposition were consistent with those observed in cultured fibroblasts. Type I and type III collagens were evident as determined by immunofluorescence staining and biochemical analysis. The osteosarcoma appeared similar to bone with regard to a high content of type I collagen, limited calcification and poor vascularization. While these sarcomas do not histologically resemble their non-transformed counterparts, analysis of their macromolecular composition confirmed the identity of their presumed cell of origin. Similar methodology could be readily applied for identification and classification of human malignant sarcomas.
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PMID:Histological and biochemical characterization of murine sarcomas. 622 75

Nine dogs with primary osteosarcoma also had concurrent bone infarctions. The median weight of the 9 dogs was less than 12 kg, and the median age was 10 years. Radiographically and histologically, bone infarctions were apparent in the limb bones and the cranium. Radiographically, there were multiple, irregular intramedullary densities, particularly in the limb bones. Histologically, there was widespread necrosis of the medullary soft tissue and bone, with proliferative new bone formation on medullary trabeculae. Collagen deposition throughout the vessel walls leading to occlusion was seen only in the intramedullary arteries.
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PMID:Bone sarcomas associated with multifocal medullary bone infarction in dogs. 694 50

Human umbilical vein endothelial cells were found to attach and partially spread on human tenascin. The attachment of endothelial cells to tenascin results in elongated cells with interconnecting processes and is distinct from the flattened appearance of endothelial cells on fibronectin, collagen, vitronectin or laminin substrata, suggesting a role for tenascin in modulating cell adhesion and motility. Endothelial attachment to tenascin was partially inhibitable by the SRRGDMS peptide derived from human tenascin and completely inhibitable by anti-integrin antibodies to alpha 2 beta 1 and alpha v beta 3. Endothelial cell attachment to tenascin could be inhibited up to 80% with anti-alpha 2 and anti-beta 1 monoclonal antibodies P1E6 and P4C10, respectively, and this was associated with a complete loss in cell spreading. In contrast, pretreatment of endothelial cells with the anti-alpha v beta 3 monoclonal antibody LM609, resulted in a 35% inhibition in cell attachment but did not alter cell spreading. In combination the anti-alpha 2 and anti-alpha v beta 3 antibodies, could completely abrogate cell spreading and attachment to tenascin-coated surfaces. Affinity purification of 125I-labeled endothelial cell extract on a tenascin matrix column followed by immunoprecipitation with monoclonal antibodies to different integrin alpha and beta subunits resulted in the identification of alpha 2 beta 1 and alpha v beta 3 integrins, respectively, as tenascin binding receptors. Collagen affinity-purified alpha 2 beta 1 receptor from endothelial cells bound not only to collagen and laminin but also to tenascin in a radio receptor binding assay. The results demonstrate that alpha 2 beta 1 and alpha v beta 3 mediate distinct endothelial cell interactions with tenascin; cell spreading and cell binding, respectively. Binding by alpha v beta 3 is mediated by the SRRGDMS site on tenascin, whereas the alpha 2 beta 1 binding site remains undefined. The interaction of alpha 2 beta 1 and alpha v beta 3 with tenascin may be regulated in a cell type-specific manner as evidenced by the binding of endothelial cell alpha 2 beta 1 and alpha v beta 3 to tenascin, and the lack of binding by the same receptors on osteosarcoma MG63 to tenascin.
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PMID:Endothelial cell attachment and spreading on human tenascin is mediated by alpha 2 beta 1 and alpha v beta 3 integrins. 769 33

Osteosarcomas contain variable amounts of bony tissue, but the mechanism of bone formation by osteosarcoma is not well understood. While a number of cultured human osteosarcoma cell lines have been established, they are maintained by different media and differ qualitatively with regard to bone formation. We examined different media for their ability to support bone formation in vitro and found the alpha-modification of Eagle's minimal essential medium supplemented with beta glycerophosphate was best for this purpose, because it contained the proper calcium and phosphate concentrations. Subsequently, we compared seven human osteosarcoma cell lines under the same experimental conditions to clarify their ability to induce bone formation. NOS-1 cells most frequently exhibited features of bone formation in vitro and in nude mice. Collagen synthesis by tumour cells themselves seemed to be the most important factor for bone volume. However, even HuO9 cells, which lacked collagen synthesis and failed to form bone in vitro, successfully formed tumours containing bone in nude mice. Histological analysis of HuO9 cells in diffusion chambers implanted in nude mice and the findings of polymerase chain reaction indicated that the phenomenon was probably due to bone morphogenetic protein.
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PMID:Bone formation in vitro and in nude mice by human osteosarcoma cells. 775 79

We have succeeded in transplanting human osteogenic sarcoma into nude mice. Morphologically, the transplanted tumor is chondrosarcoma and manifests calcification, but not ossification. This tumor is thought to be an excellent model for studying the process of morbid endochondral calcification. In this study, we have used in situ hybridization to examine expression of collagen type I, II, and III mRNAs in this tumor. In situ hybridization was carried out using biotinylated DNA probes. Hybridized probes were detected using a streptavidin-biotin-alkaline phosphatase reagent. The results showed that collagen type I and II mRNAs were produced by cells of the transplanted tumor. Collagen type I mRNA was chiefly localized in the marginal region of the tumor. Collagen type II mRNA, which was predominantly found in the premineralized region of the transplanted tumor, gradually decreased toward the mineralized region. Collagen type III mRNA was not expressed in the transplanted tumor. These results suggest that the character of progenitor chondrogenic cells might be transferred to the transplanted tumor, and that the tumor cells may change the expression of collagen genes with the differentiation or maturation.
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PMID:Expression of collagen species in a cartilaginous tumor derived from a human osteogenic sarcoma. 808 58

The purpose of this study is to evaluate the biocompatibility of zirconium compared with titanium by the in vitro study using human osteosarcoma cell line (HOS). Various characteristics of the HOS cells cultured on zirconium (99.9%) and titanium (99.9%) discs were investigated. On the colony formation of the HOS cells, there were no differences between the zirconium and titanium in colony size and number. Good proliferation of the HOS cells was observed on the zirconium as well as on the titanium. Morphological observation of the HOS cells by SEM revealed that the cells on the zirconium as well as on the titanium were flat and polygonal in shape with radial pseudopods. Collagen fibers and calcified substances were observed in the matrix of the HOS cells by TEM on the zirconium as well as on the titanium. The calcium of the HOS cell layer was stained well by Dahl's method. Analysis of the HOS cell layer by the Fourier transform infrared spectroscopy indicated that the HOS cells formed the same matrices including the apatite on the zirconium as on the titanium. Measurements of the zirconium and titanium elution into the human saliva indicated that the elution of zirconium was less than that of titanium. These results suggest that zirconium possesses as excellent biocompatibility as titanium.
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PMID:[In vitro study on biocompatibility of zirconium and titanium]. 848 10

Collagen VI is a microfibrillar protein found in the extracellular matrix of virtually all connective tissues. Three genetically distinct subunits, the alpha1(VI), alpha2(VI), and alpha3(VI) chains, associate intracellularly to form triple-helical monomers, which then assemble into disulfide-bonded dimers and tetramers before secretion. Although sequence considerations suggest that collagen VI monomers composed of all three chains are the most stable isoform, the precise chain composition of collagen VI remains controversial and alternative assemblies containing only alpha1(VI) and alpha2(VI) chains have also been proposed. To address this question directly and study the role of the alpha3(VI) chain in assembly, we have characterized collagen VI biosynthesis and in vitro matrix formation by a human osteosarcoma cell line (SaOS-2) that is deficient in alpha3(VI) production. Northern analysis showed an abundance of alpha1(VI) and alpha2(VI) mRNAs, but no detectable alpha3(VI) mRNA was apparent in SaOS-2 cells. By day 30 of culture, however, small amounts of alpha3(VI) mRNA were detected, although the level of expression was still much less than alpha1(VI) and alpha2(VI). Collagen VI protein was not detected in SaOS-2 medium or cell layer samples until day 30 of culture, demonstrating that despite the abundant synthesis of alpha1(VI) and alpha2(VI), no stable collagen VI protein was produced without expression of alpha3(VI). The alpha1(VI) and alpha2(VI) chains produced in the absence of alpha3(VI) were non-helical and were largely retained intracellularly and degraded. The critical role of the alpha3(VI) chain in collagen VI assembly was directly demonstrated after stable transfection of SaOS-2 cells with an alpha3(VI) cDNA expression construct that lacked 4 of the 10 N-terminal type A subdomains. The transfected alpha3(VI) N6-C5 chains associated with endogenous alpha1(VI) and alpha2(VI) and formed collagen VI dimers and tetramers, which were secreted and deposited into an extensive network in the extracellular matrix. These data demonstrated that alpha3(VI) is essential for the formation of stable collagen VI molecules and subdomains N10-N7 are not required for molecular assembly.
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PMID:The role of the alpha3(VI) chain in collagen VI assembly. Expression of an alpha3(VI) chain lacking N-terminal modules N10-N7 restores collagen VI assembly, secretion, and matrix deposition in an alpha3(VI)-deficient cell line. 951 40


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