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)

Osteosarcoma cells (BFO cell line) were successfully maintained in tissue culture for 3 years. BFO cells showed 100 per cent tumorigenicity by the isologous implantation, and almost the same histological features as the original BF osteosarcoma. BFO cells synthesize and secrete large quantities of alkaline phosphatase both in vitro (cell culture) and in vivo (tumor bearing mice). BFO cells showed a suppression in synthesizing the osteoinductive factor in vitro, but regained the capacity to synthesize it when implanted back into an isologous host. The cells showed rapid growth, a serum requirement, and no contact inhibition. Doubling time was 8.6 hours in a logarithmic growth phase. Cell cycle analyses by pulse labeling of 3H-thymidine was performed after synchronization of the cells by double treatment with an excess thymidine.
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PMID:Characteristics of osteosarcoma cells in culture. 26 6

Enkephalins, a group of small peptides with opiate-like activity, have been defined originally as neuropeptides. Recent reports showed, using in situ hybridization, that the enkephalin-encoding gene, proenkephalin A (pEnkA), is expressed in nondifferentiated cells of diverse mesodermal lineages. The transient expression of pEnkA in these tissues during organogenesis suggests that this gene is involved in processes such as differentiation and/or cell proliferation. In situ hybridization revealed that bone and cartilage are among the tissues that express pEnkA most actively during organogenesis. Here we show that pEnkA mRNA is abundant in normal calvaria-derived cells and in osteosarcoma-derived cell lines ROS 17/2.8 and ROS 25/1. In addition, pEnkA-derived peptides are synthesized and secreted by these cells, as revealed by specific RIA. pEnkA expression in ROS cells is decreased by osteogenin, an osteoinductive factor, and by the calcium-regulating hormone, 1,25-dihydroxyvitamin D3, whereas the osteoblastic phenotype marker, alkaline phosphatase, is increased by these factors. These results together with the inhibitory effects of pEnkA-derived peptides on alkaline phosphatase activity in ROS 17/2.8 cells suggest that pEnkA is involved in bone development and provide a model system for further analysis of pEnkA expression during this process.
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PMID:Proenkephalin A in bone-derived cells. 202 20

cDNA clones encoding osteoinductive factor (OIF) have been isolated from a bovine osteoblast library. Sequence analysis of these clones indicated that the 105-amino-acid OIF is synthesized as a larger 299-amino-acid precursor, the carboxyl terminus of which is cleaved to yield the mature protein. Northern blot analysis of bovine osteoblast mRNA revealed two OIF-specific transcripts of 1.9 and 2.4 kb. The polymerase chain reaction was used to obtain clones coding for human OIF from the osteosarcoma cell line, MG-63. The human OIF cDNA encodes a precursor of 298 amino acids that exhibits 94% identity to the bovine protein. Northern blot analysis of various cell lines and tissues indicated that expression of OIF transcripts is limited and may be restricted to cells of bone lineage.
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PMID:Molecular cloning of a novel bone-forming compound: osteoinductive factor. 237 74

Freeze-dried Saos-2, human osteosarcoma cells, and extracts of Saos-2 cells contain all components necessary to induce ectopic new bone and marrow when implanted into athymic Nu/Nu nuce. On the other hand, human osteosarcoma cells of the U-2 OS strain failed to induce bone formation under the same experimental conditions. Our aim was to compare the relative expressions of known osteoinductive factors including bone morphogenetic proteins (BMPs) and transforming growth factor-beta (TGF-beta) in these two cell lines in an attempt to explain the unique bone-inducing ability of the Saos-2 cells. Saos-2 cells expressed mRNA for BMP-1, -2, -3, -4,-6, and TGF-beta 1. The non-osteoinductive U-2 OS cells expressed BMP-2, -4, -5, -6, and -7 as well as TGF-beta 1 mRNA, while levels of BMP-1 and BMP-3 mRNA were either not detectable or detectable at a very low level in U-2 OS cells. The presence of BMP-1 and -4 protein was confirmed in Saos-2 cells by immunofluorescence, and TGF beta protein was demonstrated by bioassay in both cell types. These findings suggest that Saos-2 cells are endowed qualitatively and quantitatively with sufficient amounts of many bone morphogenetic proteins-especially BMP-1, -3, and -4-to confer osteoinductivity upon these cells. However, the absence of osteoinductivity in U-2 OS cells, despite significant mRNA expression levels of several bone morphogenetic proteins, suggests that, even though expression of one or more bone morphogenetic proteins may be present, it may not necessarily be sufficient to confer osteoinductivity upon U-2 OS cells. U-2 OS cells may be non-osteoinductive because (1) they contain inhibitors to the BMPs or secrete inhibitory binding proteins, (2) they do not process BMPs correctly, or (3) the BMPs are inappropriately localized and sequestered within the U-2 OS cells. Saos 2 cells may be osteoinductive because (1) they uniquely express BMP-1, (2) they express an appropriate combination of interactive BMPs at appropriate levels, and/or (3) the Saos-2 cells elaborate as-yet-unidentified osteoinductive factor(s).
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PMID:Expression of bone morphogenetic proteins by osteoinductive and non-osteoinductive human osteosarcoma cells. 887 5