Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0029463 (osteosarcoma)
 16,637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A proinflammatory cytokine cascade, including IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, and IL-8, is activated in response to infection or immunologic insult. Besides their immunologic effects, several of these mediators stimulate bone resorption and inhibit bone formation. Osteocalcin, the most abundant noncollagenous protein present in bone, is an osteoblast-specific product whose production closely correlates with bone formation, and which has also been implicated in control of bone resorption. IL-1 and TNF have previously been shown to down-regulate osteocalcin production in vitro and in vivo, although the mechanism of this inhibition is unknown. In the present studies, IL-1 beta and TNF-alpha both inhibited 1,25-dihydroxyvitamin D3-stimulated production of osteocalcin protein and mRNA by ROS 17/2.8 osteosarcoma cells, whereas IL-6 had no effect on protein and only weakly inhibited mRNA. To determine if down-regulation was exerted at the transcriptional level, an osteocalcin promoter-chloramphenicol acetyltransferase (CAT) fusion gene was constructed (PHOC-CAT). After transient transfection of PHOC-CAT into ROS 17/2.8 osteosarcoma cells, reporter CAT activity was up-regulated by vitamin D at concentrations above 10(-12) M. In screening studies, TNF-alpha (-57%) and IL-6 (-37%) inhibited vitamin D-stimulated osteocalcin transcription, whereas IL-1 alpha, IL-1 beta, and IL-8 had no effect. Other immune cytokines and growth factors, including IL-2, IL-3, IL-7, and M-CSF, also failed to regulate osteocalcin transcription. Despite their lack of promoter regulation, IL-1 alpha and IL-1 beta also stimulated PGE2 production by ROS 17/2.8, further confirming the ability of the host cell to respond to these mediators. In dose-response experiments, down-regulation by TNF-alpha was significant at concentrations as low as 0.14 pM (0.1 U/ml), whereas approximately 10(4)-fold higher concentration of IL-6 was required to exert a similar effect. TNF-alpha-mediated down-regulation was unaffected by indomethacin. These data demonstrate that of these cytokines, TNF-alpha alone potently down-regulates osteocalcin promoter function, whereas IL-1 acts post-transcriptionally, possibly by reducing mRNA stability. Heterogeneity therefore exists among the proinflammatory cytokines with respect to the level at which control of osteocalcin expression is exerted.
 ...
PMID:Proinflammatory cytokines tumor necrosis factor-alpha and IL-6, but not IL-1, down-regulate the osteocalcin gene promoter. 130 41

Cytokine-stimulated human osteosarcoma cells (MG-63) secrete several related chemotactic factors, including the neutrophil-activating protein interleukin 8 (IL-8) and the monocyte chemotactic protein (MCP)-1. We describe the isolation and characterization of two novel monocyte chemotactic factors from this tumor cell line. Although these proteins copurified with MCP-1 and IL-8 on heparin-Sepharose, they could be separated by cation-exchange fast protein liquid chromatography and reverse-phase high-performance liquid chromatography. The corresponding 7.5- and 11-kD proteins were NH2-terminally blocked but were identified by sequencing peptide fragments. They showed a primary structure mostly related to that of MCP-1 and were therefore designated MCP-2 and MCP-3, respectively. These molecules can be classified in a subfamily of proinflammatory proteins characterized by the conservation of cysteine residues. MCP-2 and MCP-3 are also functionally related to MCP-1 because they specifically attract monocytes, but not neutrophils, in vitro. The chemotactic potency (specific activity) was comparable for all three MCPs. Intradermal injection of these proteins in rabbits resulted in selective monocyte recruitment in vivo. Since tumor cells are good producers of leukocyte chemotactic factors, it could be questioned whether these molecules can indirectly control tumor growth by attracting leukocytes or whether they rather promote invasion by the secretion of proteases from the attracted cells.
 ...
PMID:Structural and functional identification of two human, tumor-derived monocyte chemotactic proteins (MCP-2 and MCP-3) belonging to the chemokine family. 161 66

So far, the role of fibroblasts in inflammatory processes has been underestimated. We have previously shown that stimulation of fibroblasts with viruses or bacteria results in a simultaneous production of several cytokines, including interferon-beta, interleukin (IL) 6 and colony-stimulating factors. We here report that virally infected fibroblasts produce also a chemotactic factor for granulocytes. The activity is inducible not only by measles virus but also by IL 1 beta and the double-stranded RNA poly(rI).poly(rC). This factor, when purified to homogeneity, occurs as a 6-7-kDa protein doublet upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The pure protein is serologically related to a fully characterized granulocyte chemotactic peptide (GCP) from monocytes, designated IL8. Furthermore, the chemotactic factor from fibroblasts has an NH2-terminal sequence identical to that of GCP/IL8, small differences in NH2-terminal processing being observed. Finally, in addition to diploid fibroblasts, the osteosarcoma MG-63 cell line is also a producer of GCP/IL8. It can thus be concluded that GCP/IL8 can be produced by several cell types in response to infection and that fibroblasts can contribute to chemotaxis in inflammation.
 ...
PMID:The chemotactic activity for granulocytes produced by virally infected fibroblasts is identical to monocyte-derived interleukin 8. 266 11

A phase IIb trial using liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) in combination with ifosfamide (IFX) for patients with relapsed osteosarcoma was undertaken to determine (a) the tolerability of the combination therapy, (b) if L-MTP-PE increased the toxicity of IFX, and (c) whether IFX altered or suppressed the in vivo immune response to L-MTP-PE. Patients had histologically proven osteosarcoma and pulmonary metastases that either developed during adjuvant chemotherapy or were present at diagnosis, persisted despite chemotherapy, and recurred following surgical excision. Stratum A patients were rendered clinically free of disease within 4 weeks of study entry prior to receiving combination therapy. IFX was administered at 1.8 g/m2 for 5 days every 21 days for up to eight cycles. L-MTP-PE was administered twice weekly for 12 weeks, then once weekly for 12 weeks. Once cycle of combination therapy was defined as 5 days of IFX and 3 weeks of L-MTP-PE therapy. Stratum B patients had measurable disease at study entry that was judged to be amenable to surgical resection. Stratum B patients received three cycles of combination therapy prior to surgery to judge clinical and histologic response. Postoperatively, patients received an additional five cycles. A total of nine patients were entered into the protocol: six on stratum A and three on stratum B. Serial blood samples were collected and assayed for cytokine levels (tumor necrosis factor-alpha [TNF alpha], interleukin-6 [IL-6], IL-8, neopterin, C-reactive protein). In addition, peripheral blood monocyte tumoricidal activity was evaluated pre- and post-combination therapy. Complete blood counts with differential and platelet counts were followed weekly. No increase in the toxic side effects of IFX was demonstrated when administered with L-MTP-PE nor were delays in IFX administration due to neutropenia experienced. The toxic side effects of L-MTP-PE were also not increased. Elevations of serum C-reactive protein, plasma neopterin, IL-6, IL-8, and TNF alpha following combination therapy were similar to those observed in patients treated with L-MTP-PE alone. Monocyte-mediated tumoricidal activity was elevated 24 and 72 h following L-MTP-PE and IFX therapy, similar to what has been reported following L-MTP-PE alone. Tumor specimens obtained from stratum B patients showed the histologic characteristics consistent with a "chemotherapy effect," i.e., dead, amorphous, acellular osteoid with cell drop-out.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Combination therapy with ifosfamide and liposome-encapsulated muramyl tripeptide: tolerability, toxicity, and immune stimulation. 761 44

Liposomal muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) is a biological agent in phase I and II trials for osteosarcoma and melanoma. Its mechanism of action has been linked to its ability to activate monocyte tumoricidal function and to stimulate monocyte production of tumor necrosis factor (TNF) and interleukins(IL)-1, -6, and -8. Our ultimate goal is to combine L-MTP-PE with chemotherapy. The purpose of this study was to determine whether doxorubicin (Adriamycin) interfered with the ability of L-MTP-PE to activate monocyte cytokine production. Human monocytes were cultured with or without 5-500 ng/ml of Adriamycin for 3 h and washed before being exposed to 2 micrograms/ml L-MTP-PE for 16 h. Cultured supernatants were collected and assayed for TNF, IL-1, IL-6, and IL-8. The messenger RNA expression of IL-1 alpha, IL-1 beta, TNF alpha, IL-6, and IL-8 was quantified with northern blot analysis. Adriamycin did not suppress the up-regulation of any of these cytokines. We concluded that combination therapy with L-MTP-PE and Adriamycin is feasible and that this combination warrants further investigation in a clinical setting.
 ...
PMID:Effect of Adriamycin on liposomal muramyl tripeptide's ability to up-regulate monocyte cytokine expression. 824 65

We investigated the expression of cytokine transcripts in osteoblast-like cells derived from explants of pagetic and normal bone. A reverse transcription-linked PCR was used that allowed the simultaneous analysis of a range of cytokines. Normal osteoblast-like cells were found to contain the transcripts for IL-1 beta, IL-6, and TGF-beta 1. For the first time we detected in bone cells the two other mammalian isoforms of TGF-beta, beta 2, and beta 3. Furthermore, we have also identified mRNA for IL-3 and the novel chemotactic factor, IL-8. Using this sensitive technique it was not possible to detect mRNA for IL-1 alpha, IL-2, IL-4, IL-5, IL-7, TNF-alpha, or interferon-gamma. The human osteosarcoma cell line Saos-2 also showed a similar pattern of expression of these cytokines to primary osteoblast-like cells, with the exception that TNF-alpha was also identified. Cells isolated from pagetic bone showed essentially the same profile of cytokine expression as normal bone except that TNF-alpha was also detected in two of four samples. The cytokine profile of successive populations of cells harvested from one explant culture at 9, 22, and 57 days showed a consistent pattern of cytokine expression, demonstrating the phenotypic stability of the osteoblast-like cells in long-term cultures.
 ...
PMID:PCR detection of cytokines in normal human and pagetic osteoblast-like cells. 825 52

Liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE), a new biologic response modifier, was designed to target the immunomodulator to monocytes and macrophages. Human monocytes/macrophages phagocytize L-MTP-PE, with subsequent upregulation of interleukin (IL)-1 alpha, IL-1 beta, IL-6, IL-8, tumor necrosis factor (TNF)-alpha, and monocyte chemotactic and activating factor genes and with the production and secretion of these cytokines in vitro. L-MTP-PE-activated macrophages kill tumor but not normal cells in vitro. Following i.v. infusion of L-MTP-PE into cancer patients, its uptake was demonstrated in liver, spleen, lung, and in and around metastases to lung. We also investigated whether L-MTP-PE therapy administered in a neoadjuvant setting could improve the disease-free interval in relapsed osteosarcoma patients with lung metastasis. Patients received either a 12- or 24-week course of L-MTP-PE after surgical removal of all metastases. Following L-MTP-PE infusion, induction of circulating TNF-alpha, IL-6, neopterin, and C-reactive protein was demonstrated. Disease-free intervals were calculated from the day of surgery to the day of relapse in each group and were compared with the disease-free interval for a historical control group. Those patients receiving 24 weeks of L-MTP-PE showed a significant (p < 0.03) prolongation in time to relapse. These data indicate that L-MTP-PE is an active agent against osteosarcoma and warrants further investigation in an adjuvant setting.
 ...
PMID:Liposome-encapsulated MTP-PE: a novel biologic agent for cancer therapy. 828 Jul 10

Tumor cells are capable of simultaneously producing a number of related inflammatory peptides, now classified as chemokines. We have isolated a new human granulocyte chemotactic protein (GCP-2), coproduced with interleukin-8 (GCP-1/IL-8) by osteosarcoma cells. Furthermore, the bovine homologue of human GCP-2 was purified from kidney tumor cells using the same isolation procedure. Both chemokines occur in at least four NH2-terminally truncated forms. These 5-6 kDa proteins do not differ in potency and efficacy as granulocyte chemotactic factors using a standard in vitro migration assay. The complete primary structures of human and bovine GCP-2 were disclosed by sequencing peptide fragments derived from the natural proteins. On the basis of the conservation of four cysteine residues, the two molecules are to be classified within the C-X-C chemokine family, including IL-8. Human and bovine GCP-2 are 67% similar at the amino acid level. Their sequences show only weak similarity with that of IL-8, and human GCP-2 does not cross-react in a radioimmunoassay for IL-8. Human and bovine GCP-2 are specific granulocyte chemotactic factors in that they do not attract human monocytes. Bovine GCP-2 is not species specific since it is at least as active as human GCP-2 on human granulocytes. Both chemokines can also activate postreceptor mechanisms leading to release of gelatinase B by granulocytes. This is indicative for a possible role in inflammation and tumor cell invasion.
 ...
PMID:Human and bovine granulocyte chemotactic protein-2: complete amino acid sequence and functional characterization as chemokines. 839 43

Stimulated human osteosarcoma cells (MG-63) were used as a source of granulocyte chemotactic protein (GCP). In addition to the previously isolated GCP-1/IL-8, natural forms of GRO alpha, GRO gamma, and IP-10 were purified and identified by amino acid sequence analysis. Further, a novel GCP, GCP-2, was isolated in its natural form (6 kDa) and was found to be structurally related to the other members of the IL-8 family. GRO alpha, IP-10, and GCP-2 showed heterogeneity, in that several forms of each protein were recovered. These differed in truncation at the amino terminus. Reverse phase HPLC allowed us to separate four such different forms of GCP-2. These tumor-derived factors were compared in granulocyte activation and chemotaxis assays. IL-8 induced neutrophil gelatinase B release at 2 nM, but GRO alpha and GCP-2 showed a 5- to 10-fold lower specific activity. When the migration of granulocytes through polycarbonate micropore membranes was measured, GCP-2 and GRO alpha had a maximal chemotactic index comparable to that of IL-8. The minimal effective dose for GCP-2 and GRO alpha was 3 to 10 nM, whereas the specific activity of IL-8 was at least 10-fold higher. IP-10 was not active in this assay at doses up to 100 nM. Finally, in vivo chemotaxis was measured by using granulocyte recruitment in the rabbit skin model. After intradermal injection of 200 ng/site, GCP-2 provoked a significant granulocyte infiltration, albeit to a lesser extent than did IL-8 and GRO alpha. GCP-2 did not attract monocytes in vivo nor did it induce the cells in vitro to migrate or to produce enzyme. In conclusion, this study reveals a new member of the IL-8 family and shows that these related inflammatory mediators possess different potencies and efficacies towards granulocytes.
 ...
PMID:Identification of a novel granulocyte chemotactic protein (GCP-2) from human tumor cells. In vitro and in vivo comparison with natural forms of GRO, IP-10, and IL-8. 842 27

Human granulocyte chemotactic protein 2 (GCP-2) has originally been isolated from cytokine-stimulated osteosarcoma cells as a chemokine coproduced in minute amounts together with interleukin 8. Human GCP-2 (75 residues) was synthesized on a 0.25-mmol scale using Fmoc chemistry. After disulfide bridge formation and purification, monomeric GCP-2 was recovered as a 6-kDa protein; the pure synthetic protein showed a molecular mass of 8076 Da as determined by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The exact amino acid sequence of synthetic GCP-2 was confirmed by Edman degradation. Synthetic GCP-2 was an equally active (minimal effective concentration of 1-3 nM) chemoattractant for neutrophilic granulocytes as was natural 75-residue GCP-2. At concentrations up to 30 nM, synthetic GCP-2 did not stimulate eosinophil, monocyte, or lymphocyte chemotaxis. GCP-2 induced a dose-dependent increase in [Ca2+]i in neutrophils, 1 nM being the minimal effective concentration. The GCP-2-induced [Ca2+]i increase was completely prevented by pertussis toxin. Prestimulation of neutrophils with equimolar concentrations of purified natural IL-8, GROalpha, GROgamma and ENA-78 abolished the [Ca2+]i increase in response to 1 nM GCP-2. Alternatively, the [Ca2+]i rise induced by these CXC chemokines was inhibited by pretreatment of neutrophils with GCP-2. GCP-2 stimulated [Ca2+]i increases in CXCR1- and CXCR2-transfected cells, demonstrating that GCP-2 binds to both IL-8 receptors. Intradermal injection of synthetic GCP-2 resulted in a dose-dependent neutrophil accumulation and plasma extravasation in rabbit skin. To provoke this skin reaction, GCP-2 (10 pmol/site) was nearly as effective as IL-8, indicating that it is an important complementary mediator of the inflammatory response.
 ...
PMID:Characterization of synthetic human granulocyte chemotactic protein 2: usage of chemokine receptors CXCR1 and CXCR2 and in vivo inflammatory properties. 905 80


1 2 3 4 5 Next >>