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)

TNF-alpha-treated osteosarcoma cells have an enhanced susceptibility to NK lysis which mostly depends on the increased expression of CD54 molecules. Since IL-1 and IL-6 share overlapping biological properties with TNF-alpha, we investigated whether the treatment of osteosarcoma cells with these cytokines could modify their susceptibility to NK lysis and whether these modifications were related to a different distribution of CD54, CD56 and CD58 molecules. We demonstrated that the expression of CD54 and CD58 on osteosarcomas correlated positively with the susceptibility to NK lysis and that this susceptibility was enhanced by TNF-alpha treatment but not by IL-1 and IL-6 stimulation.
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PMID:TNF-alpha but not IL-1 and IL-6 modifies the susceptibility of human osteosarcoma cells to NK lysis. 966 32

The cyclin-dependent kinase inhibitor p21(WAF1,CIP1,SDI1) plays a critical role in cell differentiation, and it has been shown to confer resistance to apoptosis. Based on this, and on evidence that activation of the gp130/signal transducer and activator of transcription (STAT) signal transduction pathway by interleukin (IL)-6 type cytokines promotes differentiation and prevents apoptosis in osteoblastic cells, we have investigated the possibility that p21 is a downstream effector of this signaling pathway in osteoblasts. We report that either oncostatin M (OSM) or IL-6 plus soluble IL-6 receptor increased the levels of p21 mRNA and protein in the osteoblast-like human osteosarcoma cell line MG63 and stimulated the activity of a 2.4-kilobase pair segment of the human p21 gene promoter. Further, nuclear extracts from cytokine-stimulated MG63 cells formed protein-DNA complexes with a 19-base pair nucleotide fragment of the p21 promoter containing a single STAT response element. The identity of the binding proteins as Stat3 and Stat1 was demonstrated with specific antibodies. In addition, and in support of a mediating role of STATs in the activation of the p21 promoter, overexpression of Stat3 potentiated the cytokine effect on the p21 promoter; whereas a dominant negative Stat3, or a mutation of the STAT response element on the promoter, significantly reduced the cytokine effect. Finally, antisense oligonucleotides complementary to p21 mRNA inhibited OSM-induced stimulation of alkaline phosphatase expression and antagonized the protective effect of OSM on anti-Fas-induced apoptosis. These results demonstrate that p21 is a downstream effector of gp130/Stat3 activation and a critical mediator of the pro-differentiating and anti-apoptotic effects of IL-6 type cytokines on human osteoblastic cells.
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PMID:Transcriptional activation of the p21(WAF1,CIP1,SDI1) gene by interleukin-6 type cytokines. A prerequisite for their pro-differentiating and anti-apoptotic effects on human osteoblastic cells. 969 69

Lymphocytes are implicated in the pathogenesis of bone disease in chronic inflammation, osteoporosis, transplantation and osteopetrosis. The effects of lymphocytes and lymphocyte-conditioned medium on bone-resorbing activity and osteoclast function have been well studied, but there are few studies of the effects of LCM on bone formation and osteoblast function. The effects of LCM on the function of the MG-63 human osteosarcoma cell line were studied, which, when stimulated with 1,25-(OH)2D3, demonstrates many of the properties of the mature human osteoblast. Lymphocytes contain oestrogen receptors and the model was also used to test the hypothesis that the effects of oestrogen on bone cells may be mediated indirectly via lymphokines. Lymphokines were measured by ELISA in human lymphocyte conditioned medium (LCM) collected following incubation of mixed lymphocytes with or without stimulation for 72 h. Unstimulated LCM increased proliferation of MG-63 cells and this increase was not affected by neutralization of interleukin 1 (IL-1), IL-3, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor (TNF), lymphotoxin alpha, or interferon gamma (IFN-gamma). Phytohaemagglutinin-stimulated LCM decreased proliferation of MG-63 cells, as well as induced expression of IL-6 mRNA, increased alkaline phosphatase production, and inhibited osteocalcin production. The decrease in proliferation was abolished by neutralization of IFN-gamma but was unaffected by neutralization of IL-1, IL-2, IL-3, IL-4, IL-6, GM-CSF, TNF, or lymphotoxin alpha. Neutralization of IFN-gamma in stimulated LCM also partially inhibited the increase in alkaline phosphatase production but had no effects on the decrease in osteocalcin production. Although oestrogen inhibited lymphocyte proliferation, the effects of LCM collected from lymphocytes in the presence of oestrogen on MG-63 cell proliferation and function was no different than the effects of LCM collected in the absence of oestrogen. LCM has multiple effects on MG-63 cell function and gene expression. Lymphocyte stimulation during the preparation of LCM further modulates these effects. Although partially mediated by IFN-gamma, the effects of LCM on these cells cannot be completely explained by individual component lymphokines. This may have implications for understanding the pathophysiology of bone loss in inflammatory disorders as well as possible feedback loops of locally generated cytokines in bone.
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PMID:Effects of human lymphocyte-conditioned medium on MG-63 human osteosarcoma cell function. 972 33

This study investigated the biocompatibility of variants of mineral trioxide aggregate (MTA), by culturing human MG63 osteosarcoma cells in the presence of materials, observing cytomorphology and cell growth, and then assaying cytokine expression from the cells. Reference materials were employed. Cell growth was quantified by preparing samples (n = 6) at 2, 4 and 7 days, for viewing by scanning electron microscopy and then scoring the amount of material that was covered by healthy cells. Subsequently, samples of culture media were tested using ELISA assays for expression of Interleukin (IL)-1alpha, IL-6, IL-8, IL-11 and macrophage colony stimulating factor (M-CSF). These assays were compared with controls where no material was present, and where media and fetal calf serum had not been exposed to cells. Results showed good cell growth on MTA. Expression of IL-6 from cells was only evident in the presence of MTA and Interpore 200. Interleukin-8 was expressed in high concentrations only in the presence of MTA. There was no evidence of expression of IL-1alpha or IL-11 with any material. Production of M-CSF was high for all materials. It appears that the variants of MTA are biocompatible and suitable for use in clinical trials.
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PMID:Osteoblast biocompatibility of mineral trioxide aggregate. 1002 86

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

Permanent human osteosarcoma cell lines are important tools for the study of bone cancer. As representative of an osteoblastic phenotype, they partly reflect their normal osteoblastic counterparts and, thus, may represent appropriate models to investigate the mechanisms involved in bone remodelling and in haematopoietic differentiation. In the present work, we describe a new human cell line, CAL 72, obtained from an osteosarcoma of the knee of a 10-year-old boy. These cells grow in continuous culture, and karyotypic analysis has revealed clonal abnormalities in number and structure, especially loss of chromosome Y. These cells exhibit morphological, immuno-histochemical and molecular characteristics of the osteoblastic lineage. Using RT-PCR, we have shown that the CAL 72 cell line expresses high levels of mRNA coding for several cytokines, such as G-CSF, GM-CSF, IL-1beta and IL-6. In view of this expression profile, the CAL 72 phenotype appears to be closer to normal primary osteoblasts than other reported osteosarcomas. Moreover, these cells express mRNA for both HGF and its receptor c-MET, suggesting that this autocrine loop might contribute to the invasiveness of the tumour from which CAL 72 originated.
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PMID:Establishment, characterisation and partial cytokine expression profile of a new human osteosarcoma cell line (CAL 72). 1038 64

ImmTher, a liposome-encapsulated lipophilic disaccharide tripeptide derivative of muramyl dipeptide, previously showed activity against liver and lung colorectal metastases in a phase I trial. The purpose of the current studies was to investigate whether ImmTher could up-regulate specific cytokine gene expression and protein production, as well as activate the tumoricidal or cytostatic activity of human monocytes. ImmTher induced the expression and production of interleukin(IL)-1alpha IL-1beta, IL-6, IL-8, IL-12, macrophage chemotactic and activating factor, and tumor necrosis factor alpha but not IL-2 or IL-10. Cytostatic or cytotoxic monocyte activity was stimulated against human Ewing's sarcoma, osteosarcoma, and melanoma cells but not breast cancer cells. Production and secretion of these cytokine proteins may play a role in the antitumor activity of ImmTher.
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PMID:ImmTher, a lipophilic disaccharide derivative of muramyl dipeptide, up-regulates specific monocyte cytokine genes and activates monocyte-mediated tumoricidal activity. 1047 6

Recent studies have identified osteoprotegerin ligand (OPG-L) as the essential factor required for osteoclastogenesis, and that the effects are prevented by its soluble receptor, osteoprotegerin (OPG). However, there are limited data at present on the regulation of OPG-L expression in human osteoblastic cells by other cytokines. Because interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and IL-6 all increase osteoclastogenesis, we assessed whether OPG-L mRNA steady-state levels were regulated by these cytokines in human osteoblastic cells. By northern analysis, IL-1beta (5 nmol/L) and TNF-alpha (9 nmol/L) increased OPG-L mRNA steady-state levels by up to two- to three-fold in normal marrow stromal cells (MS), an immortalized marrow stromal cell line (hMS), and the osteosarcoma cell line, MG-63, whereas IL-6 (2 nmol/L, with or without its soluble receptor) had no effect on OPG-L mRNA levels in any of these cells. IL-1beta and TNF-alpha increased OPG-L mRNA steady-state levels in the normal MS cells and the hMS cell line in a time- and dose-dependent fashion by up to 4.1-fold and up to 2.6-fold, respectively. Our data are thus consistent with the hypothesis that the proinflammatory and bone-resorbing cytokines, IL-1beta and TNF-alpha, but not IL-6, may stimulate osteoclastogenesis by inducing the expression of OPG-L.
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PMID:Interleukin-1beta and tumor necrosis factor-alpha, but not interleukin-6, stimulate osteoprotegerin ligand gene expression in human osteoblastic cells. 1049 28

It is unclear how mechanical stress influences bone cells. Mechanical stress causes fluid shear stress (FSS) in the bone. Osteoblast lineage cells are thought to sense FSS and regulate bone remodeling. We therefore investigated the effects of FSS on human osteoblast-like osteosarcoma cells: SaOS-2 cells in vitro. The conditioned medium of the SaOS-2 cells after 24 h of FSS (24 h-FSS CM) showed such osteoclastic phenotype inductions as significantly increasing the number of tartrate-resistant acid phosphatase (TRAP) positive multinuclear cells in rat bone marrow cells and TRAP-positive cells in human preosteoclastic cells: FLG 29.1 cells. An enzyme-linked immunosorbent assay showed interleukin-11 (IL-11) protein to increase 7-fold in the 24 h-FSS CM. A Northern analysis showed that IL-11 mRNA increased 4-fold in the SaOS-2 cells after 6 h-FSS; however, no IL-6 mRNA expression was detected. Furthermore, the anti-human IL-11 antibody significantly neutralized the osteoclastic phenotype induction of the 24 h-FSS CM. The IL-11 mRNA up-regulation in SaOS-2 cells by the 6 h-FSS was not inhibited by the anti-human transforming growth factor-beta1 antibody, but it was significantly inhibited by indomethacin. An enzymeimmunoassay showed prostaglandin E2 to increase 7-fold in the 1 h-FSS CM. These findings thus suggest that FSS induces osteoblasts to produce IL-11 (mediated by prostaglandins) and thus stimulates bone remodeling.
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PMID:Fluid shear stress increases interleukin-11 expression in human osteoblast-like cells: its role in osteoclast induction. 1062 68

Acute IL-6 secretion from osteosarcoma cells induced by the PI-linked hormones PTH(1-34) and endothelin-1 is potentiated by IL-1 beta. The present findings indicate that this potentiation is accompanied by increased signal transduction capacity. Specifically, IL-1 beta (30 pM) increased the B(max) of InsP(3) receptor binding (2. 7-fold) and immunoblot showed a 2.4-fold increase specifically in the type 1 InsP(3) receptor protein. Northern analyses of IL-1 beta-treated G-292 cells showed an 1.8-fold increase in type 1 InsP3 receptor mRNA and, in IL-1 beta-treated murine MC3T3-E1 osteoblastic cells, an 8.4-fold enhancement of the type 1 InsP(3) receptor gene transcription. Promoter reporter assays confirmed the mRNA measurements and showed the effect of IL-1 beta to be mediated by the major transcriptional regulatory region of the type 1 InsP(3) receptor promoter. The findings support the hypothesis that chronic regulators of osteoblast function, such as IL-1 beta, affect the capacity of cellular signal transduction through changes in InsP(3) receptor levels.
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PMID:IL-1 beta increases type 1 inositol trisphosphate receptor expression and IL-6 secretory capacity in osteoblastic cell cultures. 1077 2


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