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)

Bone cells are regulated by interactions with both growth factors and components of the extracellular matrix (ECM). Syndecans are cell-surface heparan sulfate proteoglycans known to play a role in cell adhesion and migration, and binding of growth factors. This study was performed to investigate the expression of syndecans by osteoblasts. Reverse transcription-linked polymerase chain reaction (RT-PCR) and Northern analysis detected syndecan transcripts in the human osteosarcoma cell lines MG-63, TE-85, SaOS-2, and U2OS; human osteoblast-like cells; rat calvarial osteoblasts; and in human bone. Western blot analysis of proteoglycans from MG-63 and TE-85 cells detected multiple heparan sulfate proteoglycan core proteins consistent with syndecan expression. Regulation of syndecan-1, -2, and -4 expression was investigated in TE-85, MG-63, and SaOS-2 cells, in response to interleukin (IL)-1beta, and IL-6, parathyroid hormone [PTH(1-34)], and 1,25(OH)2-vitamin D3. Northern analysis demonstrated that in the osteosarcoma cell lines there was no regulation of syndecan transcript levels in response to PTH(1-34) or 1,25(OH)2-vitamin D3 for 24 or 48 h. In contrast, when MG-63 and SaOS-2 cells were incubated with IL-1beta (0.01-10 ng/mL) and IL-6 (0.1-50 ng/mL) there was a dose-dependent decrease in mRNA levels for syndecan-1 and -2 at 24 and 48 h, but in response to IL-1beta upregulation in the levels of syndecan-4 transcripts. In addition, Northern analysis was performed on RNA isolated from neonatal rat calvarial osteoblasts cultured under conditions that promote osteogenesis for 0, 5, 13, 21, and 35 days. Syndecan-1 expression was observed to decrease during the culture period, syndecan-2 transcript levels increased, and there appeared to be no overall change in syndecan-4 levels. Controlled expression of syndecans by cells of the osteoblast lineage may be important in the regulation of osteoblastic proliferation and differentiation.
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PMID:Differential regulation of syndecan expression by osteosarcoma cell lines in response to cytokines but not osteotropic hormones. 1037 99

The purpose of these studies was to determine whether interferon-alpha (IFN-alpha) could enhance the sensitivity of human osteosarcoma cells to the cytotoxic actions of etoposide (VP-16). Cytostasis was determined using a [3H]thymidine incorporation assay, whereas cytotoxicity was quantified by a colony-formation assay. Low concentrations (0.1-5 U/ml) of IFN-alpha enhanced the cytostatic activity of VP-16 against MG-63, SAOS-2, and TE-85 osteosarcoma cells. The cytostatic activity of 1 microM VP-16 rose from 11% to 64%, 9% to 31%, and 10% to 71%, respectively, in the three cell lines when IFN-alpha was present. Survival fraction was also decreased when the osteosarcoma cells were treated with VP-16 + IFN-alpha as compared to either agent alone. The interaction between these two agents was determined to be synergistic rather than additive by interaction index analysis. Similar effects on cytostasis and cytotoxicity were observed when IFN-alpha was combined with Adriamycin but not cisplatin, actinomycin D, vinblastine, or amsacrine. VP-16 uptake was enhanced 12-fold in the presence of IFN-alpha, but this did not appear to translate into an increase in topoisomerase-II (topo-II)-DNA complex formation as quantified by the sodium dodecyl sulfate-KCl precipitation assay. We also could not detect alterations in topo-II expression, topo-II protein production, or cell cycle kinetics that have been shown to correlate with increased VP-16 cell sensitivity. Therefore, at this time the mechanism of enhanced cell sensitivity to the combination treatment remains unclear.
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PMID:Interferon-alpha enhances the sensitivity of human osteosarcoma cells to etoposide. 1043 62

A soluble form of tissue-nonspecific alkaline phosphatase was purified to apparent homogeneity from the culture media of Sf9 cells which had been infected with recombinant baculoviruses encoding human tissue-nonspecific alkaline phosphatase (TNSALP). To facilitate purification, an oligonucleotide consisting of 6 tandem codons for histidine and a stop codon was engineered into the TNSALP cDNA. The molecular mass of the enzyme purified through a nickel-chelate column was estimated to be 54 kDa by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. That of the native enzyme was 90 kDa as estimated by gel filtration, indicating that the purified soluble TNSALP is dimeric. The enzyme was used for production of antibodies specific for human TNSALP. Immunoblotting analysis showed a single 80-kDa band in the cell homogenate prepared from Saos-2 (human osteosarcoma) cells. However, upon digestion with peptide: N-glycosidase F, the 80-kDa TNSALP of human origin and the soluble enzyme of insect origin migrated to the same position on SDS-polyacrylamide gel, indicating that the size difference between the two enzymes is ascribed to N-linked oligosaccharides. The antibodies prepared against the purified TNSALP were found to be useful also for immunoprecipitation and immunofluorescence studies.
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PMID:A general method for rapid purification of soluble versions of glycosylphosphatidylinositol-anchored proteins expressed in insect cells: an application for human tissue-nonspecific alkaline phosphatase. 1050 77

Several studies overwhelmingly support the notion that decorin (DCN) is involved in matrix assembly, and in the control of cell adhesion and proliferation. However, nothing is known about the role of DCN during cell migration. Cell migration is a tightly regulated process which requires both adhesion (at the leading edge of the cell) and de-adhesion (at the trailing edge of the cell) from the substratum. We have determined in this study the effect of DCN on MG-63 osteosarcoma cell migration and have analyzed whether its effect is mediated by the protein core and/or the glycosaminoglycan side chain. DCN impeded the migration-promoting effect of matrix molecules (fibronectin, collagen type I) known to interact with the proteoglycan. Conversely, DCN did not counteract the migration-promoting effect of fibrinogen lacking proteoglycan affinity. DCN bearing dermatan-sulfate chains (i.e., skin and cartilage DCN) was about 20-fold more effective in inhibiting cell migration than DCN bearing chondroitin-sulfate chains (i.e., bone DCN). In addition, chondroitinase AC-treatment of cartilage DCN (which specifically removes chondroitin-sulfate chains) did not attenuate the inhibitory effect of this proteoglycan, while cartilage DCN deprived of both chondroitin- and dermatan-sulfate chains failed to alter cell migration promoted by either fibronectin or its heparin- and cell-binding domains. These data assert that the dermatan-sulfate chains of DCN are responsible for a negative influence on cell migration. However, isolated glycosaminoglycans failed to alter cell migration promoted by fibronectin, indicating that strongly negatively charged glycosaminoglycans alone cannot account for the impaired cell motility seen with DCN. Overall, these results show that the inhibitory action of DCN is dependent of substratum binding, is differentially mediated by its glycosaminoglycan side chains (chondroitin-sulfate vs. dermatan-sulfate chains), and is independent of a steric hindrance effect exerted by its glycosaminoglycan side chains.
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PMID:Decorin inhibits cell migration through a process requiring its glycosaminoglycan side chain. 1053 75

Cell culture in collagen lattice is known to be a more physiological model than monolayer for studying the regulation of extracellular matrix protein deposition. The synthesis of sulfated glycosaminoglycans (GAG) and dermatan sulfate (DS) proteoglycans by 3 cell strains were studied in confluent monolayers grown on plastic surface, in comparison to fully retracted collagen lattices. Cells were labelled with 35S-sulfate, followed by GAG and proteoglycan analysis by cellulose acetate and SDS-polyacrylamide gel electrophoresis, respectively. The 3 cell strains contracted the lattice in a similar way. In monolayer cultures, the major part of GAG was secreted into culture medium whereas in lattice cultures of dermal fibroblasts and osteosarcoma MG-63 cells but not fibrosarcoma HT-1080 cells, a higher proportion of GAGs, including dermatan sulfate, was retained within the lattices. Small DS proteoglycans, decorin and biglycan, were detected in fibroblasts and MG-63 cultures. They were preferentially trapped within the collagen gel. In retracted lattices, decorin had a higher Mr than in monolayer. Biglycan was detected in monolayer and lattice cultures of MG-63 cells but in lattice cultures only in the case of fibroblasts. In this last case, an up regulation of biglycan mRNA steady state level and down regulation of decorin mRNA was observed, in comparison to monolayers, indicating that collagen can modulate the phenotypical expression of small proteoglycan genes.
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PMID:Modulation of sulfated glycosaminoglycan and small proteoglycan synthesis by the extracellular matrix. 1082 30

Estrogen sulfatase and sulfotransferase (EST) activities are present in breast cancer tissues but there are no reports on EST in cancerous bone cells. We incubated [(3)H]estradiol-17beta with cells from a canine osteosarcoma D17 line for periods up to 24 h. Radioactive steroids were recovered from the media and separated into unconjugated and conjugated fractions using Sep-Pak C18 cartridges. The conjugate fraction was solvolyzed and the resulting free steroids were obtained from a second C18 cartridge. Little metabolism was apparent in 4 h of incubation, but by 24 h as much as one half of the radioactivity was seen in the conjugate fraction. Most of the conjugates were recovered as sulfates in all three experiments. HPLC profiles showed a limited metabolism of estradiol to other compounds except for estrone, which was clearly present in both free and sulfate fractions. These results suggest that EST may have a role in the local metabolism of estrogens in bone.
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PMID:Estradiol-17beta sulfotransferase activity in canine osteosarcoma D17 cells. 1087 35

We have succeeded in transplanting a human osteogenic sarcoma of the mandible into athymic mice. The transplanted tumor showed marked chondrogenesis and mineralization. Recently, a cell line (USAC) with phenotypes of chondrocyte has been established from the transplanted tumor. USAC cells were stellate or spindle-shaped in sparse culture, but polygonal or spherical at sub-confluency to confluency. In long-term culture, the cells were condensed and calcified nodules were formed. Production of types I, II and X collagen were detected by immunohistochemical staining and Western blot analysis. Type I collagen was strongly expressed in the stellate or spindle-shaped cells. Although type II collagen was usually present in all cells during culture, it was strongly stained in polygonal cells at confluency. Type X collagen was seen in large polygonal cells around calcified nodules. Marked [35S]-sulfate uptake and metachromasia were seen at the confluent stage and in the nodule. The cells around the nodules were positive for alkaline phosphatase, and the center of the nodules was stained with alizarin red. The potentiality of cartilage formation was confirmed by in vivo experiments using a diffusion chamber in athymic mice. These observations indicate that USAC cells maintain characteristics of chondrocyte progenitor cells and thus may serve as a useful model to study the sequential events of chondrogenesis and the process of morbid endochondral calcification. This experiment also demonstrated that transplantation of tumor tissue into athymic mice is a convenient strategy for establishment of a cell line.
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PMID:Establishment of a cell line with phenotypes of chondrocyte from a human osteogenic sarcoma of the mandible. 1094 48

To investigate the long-term efficacy of irradiated recombinant human osteogenic protein 1 (hOP-1) in bone regeneration and morphogenesis, hOP-1 was combined with a bovine collagenous matrix carrier (0, 0.1, 0.5, and 2.5 mg hOP-1/g of matrix), sterilized with 2.5 Mrads of y-irradiation, and implanted in 80 calvarial defects in 20 adult baboons (Papio ursinus). The relative efficacy of partially purified bone-derived baboon bone morphogenetic proteins (BMPs), known to contain several osteogenic proteins, was compared with the recombinant hOP-1 device in an additional four baboons. Histology and histomorphometry on serial undecalcified sections prepared from the specimens harvested on day 90 and day 365 showed that gamma-irradiated hOP-1 devices induced regeneration of the calvarial defects by day 90, although with reduced bone area compared with a previous published series of calvarial defects treated with nonirradiated hOP-1 devices. One year after application of the irradiated hOP-1 devices, bone and osteoid volumes and generated bone tissue areas were comparable with nonirradiated hOP-1 specimens. Moreover, 365 days after healing regenerates induced by 0.5 mg and 2.5 mg of irradiated hOP-1 devices showed greater amounts of bone and osteoid volumes when compared with those induced by nonirradiated hOP-1 devices. On day 90, defects treated with 0.1 mg and 0.5 mg of bone-derived baboon BMPs, combined with irradiated matrix, showed significantly less bone compared with defects receiving irradiated devices containing 0.1 mg and 0.5 mg hOP-1; 2.5 mg of partially purified BMPs induced bone and osteoid volumes comparable with the 0.1-mg and 0.5-mg hOP-1 devices. Control specimens of y-irradiated collagenous matrix without hOP-1 displayed a nearly 2-fold reduction in osteoconductive bone repair when compared with nonirradiated controls. These findings suggest that the reduction in bone volume and bone tissue area on day 90 may be caused by a reduced performance of the irradiated collagenous matrix substratum rather than to a reduction in the biological activity of the irradiated recombinant osteogenic protein. This is supported by the results of in vitro and in vivo studies performed to determine the structural integrity of the recovered gamma-irradiated hOP-1 before application in the baboon. Recoveries by high-performance liquid chromatography (HPLC) and sodium dodecyl sulfate/ polyacrylamide gel electrophoresis (SDS/PAGE)/immunoblot analyses indicated that doses of 2.5-3 Mrads of gamma-irradiation did not significantly affect the structural integrity of the recovered hOP-1. Biological activity of the recovered hOP-1 was confirmed in vitro by showing induction of alkaline phosphatase activity in rat osteosarcoma cells (ROS) and in vivo by de novo endochondral bone formation in the subcutaneous space of the rat. These findings in the adult primate indicate that a single application of gamma-irradiated hOP-1 combined with the irradiated xenogeneic bovine collagenous matrix carrier is effective in regenerating and maintaining the architecture of the induced bone at doses of 0.5 mg/g and 2.5 mg/g of carrier matrix.
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PMID:Long-term evaluation of bone formation by osteogenic protein 1 in the baboon and relative efficacy of bone-derived bone morphogenetic proteins delivered by irradiated xenogeneic collagenous matrices. 1097 99

Syndecan-1 is a heparan sulfate proteoglycan expressed on the surface of, and actively shed by, myeloma cells. Hepatocyte growth factor (HGF) is a cytokine produced by myeloma cells. Previous studies have demonstrated elevated levels of syndecan-1 and HGF in the serum of patients with myeloma, both of negative prognostic value for the disease. Here we show that the median concentrations of syndecan-1 (900 ng/mL) and HGF (6 ng/mL) in the marrow compartment of patients with myeloma are highly elevated compared with healthy controls and controls with other diseases. We show that syndecan-1 isolated from the marrow of patients with myeloma seems to exist in an intact form, with glucosaminoglycan chains. Because HGF is a heparan-sulfate binding cytokine, we examined whether it interacted with soluble syndecan-1. In supernatants from myeloma cells in culture as well as in pleural effusions from patients with myeloma, HGF existed in a complex with soluble syndecan-1. Washing myeloma cells with purified soluble syndecan-1 could effectively displace HGF from the cell surface, suggesting that soluble syndecan-1 can act as a carrier for HGF in vivo. Finally, using a sensitive HGF bioassay (interleukin-11 production from the osteosarcoma cell line Saos-2) and intact syndecan-1 isolated from the U-266 myeloma cell line, we found that the presence of high concentrations of syndecan-1 (more than 3 microg/mL) inhibited the HGF effect, whereas lower concentrations potentiated it. HGF is only one of several heparin-binding cytokines associated with myeloma. These data indicate that soluble syndecan-1 may participate in the pathology of myeloma by modulating cytokine activity within the bone marrow.
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PMID:High levels of soluble syndecan-1 in myeloma-derived bone marrow: modulation of hepatocyte growth factor activity. 1104 95

Sulfate conjugation is an important pathway in the metabolism of many drugs, xenobiotic compounds, and hormones. Sulfotransferases (SULTs) catalyze these reactions and have been detected and characterized in various human tissues including the liver and small intestine. Substrates for SULTs that include estrogen and thyroid hormones have well-established roles affecting skeletal integrity and disease processes. We performed the following studies to determine the presence of SULTs in human osteoblast-like cells, and to compare their characteristics to SULTs expressed in other human tissues. Four osteosarcoma cell lines (SaOS-2, U2-OS, PR, and HOS-TE85) were screened for the presence of four different SULT activities. Predominant activities were found for SULT1A1 in SaOS-2 cells, and SULT-1A3 in HOS-TE85 cells. Several biochemical properties of each enzyme that included apparent K(m) values, thermal stabilities, and responses to the inhibitors 2,6-dichloro-4-nitrophenol and NaCl were used to further characterize the SULT activities. High-performance liquid chromatography (HPLC) of the reaction products confirmed the known products of SULT1A1 and SULT1A3. When the mature human osteoblast HOB-03-CE6 cell line was tested for activity alone, the predominant activity was SULT1A3, with minimal SULT1A1. The results indicate that SULT1A1 and SULT1A3 are present in human osteosarcoma and mature osteoblast cell lines, and that the characteristics of the osteosarcoma cell SULTs are similar to those expressed in other human tissues. SULTs may have regulatory roles in the deactivation of thyroid hormones or estrogenic compounds in bone, and thus may affect hormone action and bone responses in the human skeleton.
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PMID:Thermostable (SULT1A1) and thermolabile (SULT1A3) phenol sulfotransferases in human osteosarcoma and osteoblast cells. 1142 50


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