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)

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.
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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

Monocyte chemotactic proteins (MCP) belong to a group of structurally and functionally related factors, called chemokines. To facilitate additional characterization of the recently identified MCP-2, the 76-residue protein was chemically synthesized. The synthetic 7-kDa monomeric protein was chemotactic for monocytes at 1 nM and was biochemically similar to natural MCP-2. Sensitive radioimmunoassays for both MCP-1 and MCP-2 were developed. These RIAs were specific in that no cross-reactivity could be observed, and other chemokines or cytokines were not detected. Induction of MCP-1 and MCP-2 in human diploid fibroblasts and peripheral blood leukocytes as well as osteosarcoma, epidermal carcinoma, and melanoma cells by the cytokines IL-1 beta, IFN-beta, and IFN-gamma and cytokine inducers such as dsRNA, virus, endotoxin, mitogen, and phorbol ester was studied. In connective tissue cells, IL-1 beta was the best inducer of MCP-1, but IFN-gamma was a superior inducer of MCP-2. Mononuclear cells also proved to be a source of MCP-1 and MCP-2 when stimulated by most of the inducers tested. Granulocytes, however, were inefficient producers. Measles virus induced MCP-1 and MCP-2 in most cell types. In general, the yields of MCP-2 were at least 10-fold lower than those of MCP-1. It is concluded that, although MCP-2 is often coproduced with MCP-1, regulation of expression of the two chemokines is not identical. It remains to be studied under which pathological conditions MCP-2 is released in vivo and whether MCP-1 and MCP-2 can activate different target cells.
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PMID:Induction of monocyte chemotactic proteins MCP-1 and MCP-2 in human fibroblasts and leukocytes by cytokines and cytokine inducers. Chemical synthesis of MCP-2 and development of a specific RIA. 818 67

When human MG-63 osteosarcoma cells are triggered with IL-1 beta, they produce, among various other cytokines, also monocyte chemotactic proteins (MCPs). Homogeneous MCP-1, MCP-2 and MCP-3 were found to induce production of gelatinase B and chemotaxis of monocytes. Based on the almost complete amino acid sequence of natural MCP-3, two sets of degenerated oligonucleotides were used for the amplification of MCP-3 cDNA. Total RNA from stimulated MG-63 cells was reverse transcribed and PCRs done on the mRNA:cDNA duplex. Using the PCR-product, several cDNAs were isolated from a cDNA library of IL-1-stimulated MG-63 cells. From the cDNA sequence the complete primary structure of the protein was deduced: MCP-3 shows 71% and 58% amino acid homology with MCP-1 and MCP-2, respectively. Our study establishes MCP-3 as an inflammatory cytokine that regulates macrophage functions. Because MCP-3 is often produced by tumor cell lines and regulates protease secretion by macrophages, its production might also contribute to invasion and metastasis of cancer cells.
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PMID:Human monocyte chemotactic protein-3 (MCP-3): molecular cloning of the cDNA and comparison with other chemokines. 846 Oct 11

Stimulated MG-63 osteosarcoma cells have been used as a source to purify and identify the monocyte chemokines MCP-1, MCP-2 and MCP-3. In comparison with MCP-1, the production yields of MCP-2 and MCP-3 in these cells are rather low and variable. Although the protein sequence of human MCP-2 is identified, its DNA sequence remains elusive. A degenerate primer set was used to isolate an MCP-2 gene fragment from the chemokine YAC contig on human chromosome 17. Based on the gene sequence of MCP-2, a unique primer set was synthesized and used to screen cDNA libraries for the presence of MCP-2 transcripts by PCR. The complete MCP-2 cDNA was cloned from a human bone marrow cDNA library and sequenced. The cDNA-derived protein sequence was identical to that of purified natural MCP-2, except for Gln46 which replaced Lys46. There seem thus to exist two MCP-2 allelic variants because at position 46 the codons of two residues (Lys46 and Gln46) were detected in individual genomes. As shown by Northern hybridization, the MCP-2 steady-state mRNA levels in normal diploid fibroblasts were increased by IL-1 beta, IFN-gamma and the double-stranded RNA poly rI:rC. RT-PCR analysis showed induction of MCP-2 mRNA in MG-63 cells by IFN-gamma and IL-1 beta. The regulated production of MCP-2 by tumor cells and normal mesenchymal cells is indicative of a role in neoplasia and inflammatory host responses.
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PMID:Human monocyte chemotactic protein-2: cDNA cloning and regulated expression of mRNA in mesenchymal cells. 907 Aug 81

Human Monocyte Chemotactic Protein (MCP)-2 has originally been isolated from stimulated osteosarcoma cells as a chemokine coproduced with MCP-1 and MCP-3. Here, a 5'-end extended MCP-2 cDNA was cloned from a human testis cDNA library. It encoded a 76 residue MCP-2 protein, but differed from the reported bone marrow-derived MCP-2 cDNA sequence in codon 46, which coded for a Lys instead of a Gln. This MCP-2Lys46 variant, caused by a single nucleotide polymorphism (SNP), was biologically compared with MCP-2Gln46. The coding regions were subcloned into the bacterial expression vector pHEN1, and after transformation of Escherichia coli, the two MCP-2 protein variants were recovered from the periplasm. The recombinant proteins were purified to homogeneity by heparin-Sepharose affinity chromatography and reversed-phase HPLC. Edman degradation revealed a Gln residue at the NH2 terminus instead of a pGlu. To evaluate the influence of the cyclization, this Gln was chemically converted into pGlu in both MCP-2 variants. The conversion was confirmed by electrospray mass spectrometry. rMCP-2Gln46 and rMCP-2Lys46 and the NH2-terminal cyclic counterparts were tested on monocytic cells in calcium mobilization and chemotaxis assays. No significant difference in biological activity was observed between the rMCP-2Gln46 and rMCP-2Lys46 isoforms. However, for both MCP-2 variants the NH2-terminal pyroglutamate was shown to be essential for chemotaxis, but not for calcium mobilization. NH2-terminal truncation of rMCP-2Lys46 by the serine protease CD26/dipeptidyl peptidase IV (CD26/DPP IV) resulted in the cleavage of the NH2-terminal Gln-Pro dipeptide, whereas synthetic MCP-2 with an amino-terminal pGlu remained unaffected. CD26/DPP IV-clipped rMCP-2Lys46(3-76) was almost completely inactive in both chemotaxis and signaling assays. These observations indicate that the NH2-terminal pGlu in MCP-2 is necessary for chemotactic activity but also that it protects the protein against degradation by CD26/DPP IV.
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PMID:Functional comparison of two human monocyte chemotactic protein-2 isoforms, role of the amino-terminal pyroglutamic acid and processing by CD26/dipeptidyl peptidase IV. 973 Aug 40

Human monocyte chemotactic protein-2 (MCP-2) is a member of the CC chemokine family. It is produced by mononuclear leukocytes, diploid fibroblasts, and tumor cells after induction with IL-1beta or IFN-gamma. To understand the transcriptional regulation of the gene, we have analyzed the structure and function of the promoter region. The sequence of the 5'-flanking region was determined and the transcription start site was found to be located at 68 nucleotides upstream of the ATG translation start codon. 5'-Deletion mutants were generated and transfected into E6SM diploid fibroblasts and MG-63 osteosarcoma cells. Expression was measured by luciferase assay in transfected unstimulated cells and after stimulation with IL-1beta, IFN-gamma, or a combination. The region between nucleotides -143 and -73 (relative to the transcription initiation site), containing putative cis-elements for GATA-1, H-APF1, AP-1, and GAS, is important for basal transcription levels in both cell lines. Stimulation for 18 h with IL-1beta alone failed to affect expression of any of the constructs both in diploid fibroblasts and in osteosarcoma cells. In both cell lines IFN-gamma increased the activity of all mutants that possessed the region between -340 and -301. In MG-63 cells, stimulation with the combination of IL-1beta and IFN-gamma caused an additional increase in expression of the constructs from -340 onward. Finally, the presence of transcription factors in nuclear extracts of MG-63 cells and their specificity to bind to various oligonucleotide probes in this [-340; -301] region were evidenced by electromobility shift assays. These results show that IFN-gamma, produced by lymphocytes and NK cells, induces the transcription of the MCP-2 gene in fibroblasts and thereby can indirectly contribute to recruitment of various leukocyte cell types to inflammatory sites.
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PMID:Transcriptional control of the human MCP-2 gene promoter by IFN-gamma and IL-1beta in connective tissue cells. 1049 22