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)

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.
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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.
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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