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

An osteosarcoma, occurring in the maxillary alveolar ridge of a 17-year-old girl is presented. The tumor consisted predominantly of pleomorphic, mainly osteoblast-like and anaplastic cells. At the ultrastructural level the osteoblast-like cells were characterised by excentrically situated lobed nuclei, extensively swollen, dilated and rough endoplasmic reticulum (RER), polymorphism of mitochondria and sparse Golgi-systems. The undifferentiated cells were characterized by large, electron-lucent nuclei and paucity of non-dilated RER and mitochondria. The intercellular matrix contained collagen fibers with areas of focal collections of calcification.
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PMID:Osteosarcoma of the maxilla. Case report and ultrastructural study. 194 May 1

Direct conversion of typical fibroblasts to chondrocytes in the mouse fibrous connective tissue induced by bone morphogenetic protein (BMP) was observed by light as well as electron microscopy. A pellet containing BMP obtained from a murine osteosarcoma was transplanted into the dorsal subfascia of 5 week-old mice. Until 3 days after implantation of BMP, all the connective tissue cells in the pellet region of the dorsal subfascia showed the fine structural features of typical fibroblasts. The cells in the pellet region changed their shape from spindle-like to polygonal by 5 days after implantation. At this time, small vacuoles 150-450 nm and vesicles 40-60 nm in diameter, containing a homogeneous substance of low electron density, appeared in the cytoplasm of the cells. A small amount of extracellular substance, showing metachromasia by toluidine blue staining, was seen around the cells. Moreover, autoradiography of 35S revealed the uptake of sulfur by the cells and its accumulation in the extracellular substance around the cells in the pellet region at 5 days. The rough endoplasmic reticulum and Golgi apparatus increasingly developed with time and after 7 days both elements were distributed throughout the cytoplasm. The cytoplasmic small vacuoles and vesicles also increased in number with time, and the metachromatic extracellular substance containing fine filamentous meshwork and many tiny particles, which was regarded as the matrix of cartilage, also increased rapidly in amount. By 9 days, the cells in the pellet region became oval or round in shape, showing many short cytoplasmic processes.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Ultramicroscopic aspects of the conversion of fibroblasts to chondrocytes in the mouse dorsal subfascia induced by bone morphogenetic protein (BMP). 203 64

A case of extraskeletal osteosarcoma was observed in the thigh of a 33-year-old male patient. Ultrastructurally the tumor was characterized by the presence of a particular dense type of cell, the nucleus of which showed a characteristic combination of features: large amounts of condensed marginated chromatin, prominent perichromatin granules, vermicellar bodies, and undulating microtubules. The tumor also contained intermediate-type cells with a more typical osteoblastic appearance, and more blastic cells. All three cell types contained varying amounts of dilated rough endoplasmic reticulum with prominent inclusions of crystalline material showing a hexagonal or banded pattern, indicating that the cells represent different stages of maturation rather than genuinely different types of cells. Dense cells showing the same characteristic combination of nuclear features have been described once before in a case of parosteal osteosarcoma. Our results indicate that these cells are a particular form of osteogenic cell. The presence of undulating microtubules and vermicellar bodies suggest a possible association with the presence of virus and/or increased levels of interferon.
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PMID:Extraskeletal osteosarcoma with unusual ultrastructural features. 216 72

Chemotaxis is an important step in monocyte recruitment in inflammation, wound healing, and tumor growth. We reported previously that monocyte chemotactic activity secreted by malignant cells and normal smooth muscle cells is associated with a protein or family of proteins that are related to the monocyte-specific smooth muscle cell-derived chemotactic factor (SMC-CF) (Graves, D. T., Jiang, Y. L., Williamson, M. J., and Valente, A. J. (1989) Science 245, 1490-1493). Similar monocyte chemotactic proteins (MCP-1) produced by U-105MG human glioma cells have also been identified (Yoshimura, T., Robinson, E. A., Tanaka, S., Appella, E., Kuratsu, J., and Leonard, E. J. (1989) J. Exp. Med. 169, 1449-1459). We now report that the MCP-1 gene is expressed in MG-63 human osteosarcoma and vascular smooth muscle cells and that SMC-CF antiserum specifically immunoprecipitates proteins synthesized by U-105MG glioma cells. Experiments were undertaken to elucidate the processing pathway of MCP-1/SMC-CF-like proteins in each of these cell types. These experiments demonstrate that larger MCP-1/SMC-CF-like proteins are derived from a Mr = 9000 precursor. Post-translational modification involves the addition of O-linked carbohydrates and sialic acid residues. Differences in carbohydrate processing account for the heterogeneity in MCP-1/SMC-CF-like proteins produced by different cell types. Secretion of these proteins occurs rapidly following processing events in the endoplasmic reticulum-Golgi compartment.
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PMID:Post-translational modification of a monocyte-specific chemoattractant synthesized by glioma, osteosarcoma, and vascular smooth muscle cells. 221 4

The osteosarcomas were subclassified into osteoblastic, fibroblastic, chondroblastic and telangiectatic types and examined by electron microscopy. Their immunohistochemical reactions were also studied. In an overall survey of the above types, fibroblast-like cells revealed poorly developed cytoplasmic organelles with rather short, branching rough endoplasmic reticulum, mixed with osteoblast-like cells that were hardly distinguishable from the former. They appeared to be an early stage of an osteoblastic cell lineage from the distribution and development of their cell organelles and highly positive vimentin activity. The tumor cells in malignant cartilage varied in appearance from chondroblast-like to osteoblast-like cells. All types of tumor cells expressed alkaline phosphatase activity to a significant degree. Immunohistochemical staining showed a mixture of procollagen type I-positive cells among the cells positive for both procollagen type II and S-100 protein in the malignant cartilage. Irrespective of any ultrastructural differences between these various tumor cell types, they all revealed a significant degree of ALPase activity unlike other types of bone tumors, suggesting that the tumor cells which constitute the various types of osteosarcoma are derived from a common precursor cell.
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PMID:Osteosarcoma. Ultrastructural and immunohistochemical studies on alkaline phosphatase-positive tumor cells constituting a variety of histologic types. 316 60

Confronting cisternae of the endoplasmic reticulum recognized in tumor cells of 7 cases of osteosarcoma were presented. They were found in the mitotic cells as well as in the cytoplasms of interphase cells. The more the mitotic cells were observed in 1 micron-thick sections, the more frequently those membranous structures were encountered in the corresponding ultrathin sections. In the interphase cells, such structures were located around Golgi apparatus or close to the nucleus. Occasionally, they were composed of a pair of closely apposed cisternae of the nuclear membrane and the rough endoplasmic reticulum. These results seem to indicate that the nuclear envelope which is disrupted and reformed during mitosis in rapidly proliferating cells takes part in the formation of the confronting cisternae of the endoplasmic reticulum.
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PMID:The presence of intracytoplasmic confronting cisternae of the endoplasmic reticulum in osteosarcoma cells in interphase. 345 51

The human osteosarcoma-derived cell line U-2 OS expresses c-sis mRNA and synthesizes platelet-derived growth factor (PDGF)-like proteins. Pulse-chase experiments indicate that proteins of 23 kDa and 180 kDa are synthesized first. The 23-kDa protein undergoes dimerization and proteolysis, giving rise to the 30-kDa dimeric protein secreted by the cells. The 180-kDa protein is proteolytically cleaved in a complex series of steps that give rise to several intracellular species. It is also the likely precursor of high molecular mass PDGF-like or PDGF-associated proteins secreted by these cells. The processing and secretion of the 180-kDa protein is slower than that of the 23-kDa protein. Subcellular fractionation and studies with the antibiotic monensin indicate that the processing events occur in the Golgi-endoplasmic reticulum compartment of U-2 OS cells.
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PMID:Identification of processing events in the synthesis of platelet-derived growth factor-like proteins by human osteosarcoma cells. 346 62

A clonal rat osteogenic sarcoma cell line, UMR 106-06, was used to study the effects of retinoic acid (RA) on its growth and morphology. Retinoic acid caused a reversible, time and dose-dependent inhibition of growth. RA-treated cells were larger, were more adherent to the substratum, and contained fewer mitotic figures. Half-maximal growth inhibition was observed at 10(-8) M. Among the naturally occurring retinoids, RA was clearly the most potent while the arotinoids, Ro 13-7410 and Ro 13-6298, were approximately 50 times more potent than was RA. A similar range of potencies was observed in the cloning efficiencies of the cells in soft agar. Fluorescence microscopy revealed that RA treatment increased the cellular content and organization of F-actin fibers. Ultrastructural changes include decreased chromatin dispersion and increased number of nucleoli per nucleus, decreased rough endoplasmic reticulum, decreased electron density and number of mitochondria, and increased formation of microfilaments and microtubules. These results identify this clonal cell line, which has been extensively characterized as the malignant counterpart of the normal osteoblast, as a target for vitamin A action.
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PMID:Effect of retinoids on the growth, ultrastructure, and cytoskeletal structures of malignant rat osteoblasts. 389 72

Sixteen cases of typical highly malignant osteosarcoma were investigated by light, electron, and immunofluorescence microscopy to demonstrate the presence of collagen types I-III. It was shown that, in light-microscopically anaplastic areas of the tumor, collagen type III predominates, while only very few membranes of collagen type I are observed. Ultrastructurally, the cells are characterized by numerous free ribosomes in their cytoplasm and only a few membranes of granular endoplasmic reticulum (ER). In osteoblastic areas, collagen type I is increased, while type-III collagen is decreased. The cytoplasm of cells contains markedly more granular ER. An increasing mineralization of matrix is observed. In fibroblastic areas of the tumors, collagen types I and III are codistributed. Tumor cells have a fibroblast appearance with elongated nuclei and well developed granular ER. The chondroblastic areas, characterized by immature neoplastic cartilage, contain varying amounts of collagen type II. Chondroblast-like tumor cells have typical ring-shaped membranes of granular ER in their cytoplasm. The evidence of different collagen types in osteosarcomas lends additional support to the concept that a pluripotent mesenchymal cell is the stem cell of osteosarcomas.
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PMID:Biologic characterization of human bone tumors. II. Distribution of different collagen types in osteosarcoma--a combined histologic, immunofluorescence and electron microscopic study. 636 Oct 42

Although the primary cell type in human osteosarcoma is usually a neoplastic osteoblast, numerous other mesenchymal cell types may coexist in the same tumor. Previously described cloned, long-term osteosarcoma cell lines have had an osteoblastic phenotype. In this report, we describe a nonosteoblastic, long-term cell line derived from an osteosarcoma in a patient with Paget's disease. The cell line (FM-2) is nontransformed in having a low saturation density and anchorage-dependent growth, and it is nontumorigenic in nude mice. Important features of its fine structure include numerous elongated mitochondria, abundant Golgi and lysosomes, and a poorly developed rough endoplasmic reticulum. The line has high levels of lysosomal enzymes (acid phosphatase and N-acetylglucosaminidase) and low levels of alkaline phosphatase. It lacks numerous macrophage markers (lysozyme, C3, Fc receptors, and M1 antigen). The FM-2 line had a dose-dependent cyclic AMP response (7-fold increase) following treatment with calcitonin but not with parathormone. In 125I-calcitonin-binding experiments, we calculated approximately 5.3 +/- 0.2 X 10(3) receptor sites/cell with a kd of 1.8 +/- 0.1 X 10(-9) M. Conditioned medium from the FM-2 line was a potent stimulator of calcium release as assayed in a 45Ca-labeled fetal rat bone organ culture. This activity was not prostaglandin, vitamin D, parathormone, or epidermal growth factor, which are known stimulators of bone resorption. The FM-2 line does not appear to be derived from an osteoblast, macrophage, or fibroblast and may represent a calcitonin-responsive bone stem cell.
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PMID:Characteristics of a calcitonin-responsive cell line derived from a human osteosarcoma. 657 18


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