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)

An anti-cell adhesion globulin was purified from human plasma by heparin-affinity chromatography. The purified globulin inhibited spreading of osteosarcoma and melanoma cells on vitronectin, and of endothelial cells, platelets, and mononuclear blood cells on vitronectin or fibrinogen. It did not inhibit cell spreading on fibronectin. The protein had the strongest antiadhesive effect when preadsorbed onto the otherwise adhesive surfaces. Amino acid sequence analysis revealed that the globulin is cleaved (kinin-free) high molecular weight kininogen (HKa). Globulin fractions from normal plasma immunodepleted of high molecular weight kininogen (HK) or from an individual deficient of HK lacked adhesive activity. Uncleaved single-chain HK preadsorbed at neutral pH, HKa preadsorbed at pH greater than 8.0, and HKa degraded further to release its histidine-rich domain had little anti-adhesive activity. These results indicate that the cationic histidine-rich domain is critical for anti-adhesive activity and is somehow mobilized upon cleavage. Vitronectin was not displaced from the surface by HKa. Thus, cleavage of HK by kallikrein results in both release of bradykinin, a potent vasoactive and growth-promoting peptide, and formation of a potent anti-adhesive protein.
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PMID:Inhibition of cell adhesion by high molecular weight kininogen. 137 Apr 94

Some integrin receptors have been reported to be functionally distinct in different cell types. In endothelial and melanoma cells, the vitronectin receptor, alpha v beta 3 binds fibrinogen (fg) and von Willebrand factor (vWf) in addition to vitronectin itself, whereas it fails to do so in MG-63 osteosarcoma cells. In this report, it is shown that, in the presence of Mn2+, MG-63 cells attach more efficiently to vitronectin and acquire the de novo capacity to adhere to fg- and vWf-coated surfaces. The latter phenomenon occurs with full cell spreading, F-actin microfilament organization, and alpha v and beta 3 clustering at focal contacts. In contrast, beta 1 and beta 5 do not localize to adhesion plaques under the same experimental conditions. An antiserum to the beta 3 chain and a synthetic peptide containing the sequence Gly-Arg-Gly-Asp-Ser-Pro block MG-63 attachment to fg and vWf in the presence of Mn2+. The minimal active concentration of Mn2+ is in the range of 0.1 to 1 microns. These data suggest that the acquired capacity of MG-63 to attach to fg and vWf in the presence of Mn2+ is mediated by alpha v beta 3 and that differences in alpha v beta 3 receptor specificity may be modulated by exogenous factors.
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PMID:Role of manganese in MG-63 osteosarcoma cell attachment to fibrinogen and von Willebrand factor. 171 76

To isolate collagen-binding cell surface proteins, detergent extracts of surface-iodinated MG-63 human osteosarcoma cells were chromatographed on affinity matrices of either type I collagen-Sepharose or Sepharose carrying a collagen-like triple-helical peptide. The peptide was designed to be triple helical and to contain the sequence Arg-Gly-Asp, which has been implicated as the cell attachment site of fibronectin, vitronectin, fibrinogen, and von Willebrand factor, and is also present in type I collagen. Three radioactive polypeptides having apparent molecular masses of 250 kD, 70 kD, and 30 kD were distinguishable in that they showed affinity toward the collagen and collagen-like peptide affinity columns, and could be specifically eluted from these columns with a solution of an Arg-Gly-Asp-containing peptide, Gly-Arg-Gly-Asp-Thr-Pro. These collagen-binding polypeptides associated with phosphatidylcholine liposomes, and the resulting liposomes bound specifically to type I collagen or the collagen-like peptide but not to fibronectin or vitronectin or heat-denatured collagen. The binding of these liposomes to type I collagen could be inhibited with the peptide Gly-Arg-Gly-Asp-Thr-Pro and with EDTA, but not with a variant peptide Gly-Arg-Gly-Glu-Ser-Pro. We conclude from these data that these three polypeptides are membrane molecules that behave as a cell surface receptor (or receptor complex) for type I collagen by interacting with it through the Arg-Gly-Asp tripeptide adhesion signal. The lack of binding to denatured collagen suggests that the conformation of the Arg-Gly-Asp sequence is important in the recognition of collagen by the receptor complex.
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PMID:A cell surface receptor complex for collagen type I recognizes the Arg-Gly-Asp sequence. 346 4

The usefulness of radioiodinated fibrinogen in tumor localization and of coagulation in 80 cancer patients was investigated. Tumors externally detected demonstrated positive localization in 63% of all cases and in 100% of osteosarcomas of limbs. Fibrinogen half-life was reduced in cancer patients particularly in cases with lymphoma, Hodgkin's disease and osteosarcoma irrespectively of basal plasma fibrinogen levels. In lymphoma and ovarian cancer, fibrinogen degradation products were correlated to radiofibrinogen T/2 reduction. In patients with the lowest fibrinogen T/2 and platelet count, heparin infusion therapy returned the fibrinogen half-life to normal range. Present results suggest the existence of enhanced coagulation both inside and around the tumor and/or dissemination in early cancer as well as in the more advanced stage.
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PMID:Radioiodinated fibrinogen distribution in cancer patients. 615 67

Saos-2 cells, derived from a primary human osteosarcoma, caused dose-dependent platelet aggregation in heparinised human platelet-rich plasma. Saos-2 tumour cell-induced platelet aggregation (TCIPA) was completely inhibited by hirudin but unaffected by apyrase. The cell suspension shortened the plasma recalcification times of normal, factor VIII-deficient and factor IX-deficient human plasmas in a dose-dependent manner. However, the cell suspension did not affect the recalcification time of factor VII-deficient plasma. Moreover, a monoclonal antibody (MAb) against human tissue factor completely abolished TCIPA. Flow cytometric analysis using anti-integrin MAbs as the primary binding ligands demonstrated that the integrin receptors alpha v beta 3, alpha 5 beta 1 and alpha 6 beta 1 were present of Saos-2 cells, which might mediate tumour cell adhesion to extracellular matrix. Rhodostomin, an Arg-Gly-Asp (RGD)-containing snake venom peptide which antagonises the binding of fibrinogen to platelet membrane glycoprotein IIb/IIIa, prevented Saos-2 TCIPA as well as tumour cell adhesion to vitronectin, fibronectin and collagen type I. Likewise, the synthetic peptide Gly-Arg-Gly-Asp-Ser (GRGDS) showed a similar effect. On a molar basis, rhodostomin was about 18,000 and 1000 times, respectively, more potent than GRGDS in inhibiting TCIPA and tumour cell adhesion.
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PMID:The Arg-Gly-Asp-containing peptide, rhodostomin, inhibits in vitro cell adhesion to extracellular matrices and platelet aggregation caused by saos-2 human osteosarcoma cells. 784 Oct 39

Bone sialoprotein (BSP), a small (approximately 80,000 M(r)) integrin binding, RGD-containing bone matrix glycoprotein, has been purified in milligram quantities from the serum-free medium of the rat osteosarcoma cell line UMR-106-BSP using nondenaturing conditions. Routine protein purification without serine protease inhibitors or reducing agents consistently resulted in three major fragments. The largest fragment (E1) started at amino acid 117 and did not bind to antibodies made to the RGD region of the protein. Furthermore, the smallest fragment (E3), was shown by sequencing to contain the RGD region of the protein. Digestion of intact BSP with highly purified chymotrypsin also resulted in a large fragment (C1) with properties nearly identical to those of E1. The large, non-RGD-containing fragments, E1 and C1, as well as the intact BSP, supported attachment by normal human bone cells and human skin fibroblasts in vitro. Attachment to the intact BSP was totally blocked by 0.4 mM GRGDS peptide. Both preparations of skin fibroblasts and approximately half of the preparations of normal human bone cells, however, also would not attach to the E1 and C1 fragments in the presence of 0.4 mM GRGDS peptide. In contrast, half of the bone cell preparations had significant attachment activity to E1 (> 50%) and C1 (> 25%) in the presence of 0.4 mM GRGDS peptide. These data suggest that cleavage of the BSP results in either (1) the exposure of a previously unavailable or cryptic cell attachment site or (2) a conformational change that increases the affinity of the complex between a non-RGD-encoded binding region of the E1 and C1 fragments and at least one receptor. The possible homology of the second, non-RGD-suppressible site of BSP with the second cell attachment site on the gamma chain of fibrinogen is discussed.
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PMID:Purification and fragmentation of nondenatured bone sialoprotein: evidence for a cryptic, RGD-resistant cell attachment domain. 821 61

The vitronectin receptor (alpha v beta 3) is a member of the integrin superfamily that mediates cell attachment on arginine-glycine-aspartic acid (RGD)-containing adhesive proteins. A solid-phase microtiter assay was developed to investigate the binding properties of purified alpha v beta 3, using tritiated [3H]SK&F-107260 as the radiolabeled ligand. alpha v beta 3, purified from human platelets, human placenta, and chicken osteoclasts, bound [3H]SK&F-107260 saturably and specifically. Saturation binding studies using platelet alpha v beta 3 revealed a single class of high affinity binding sites, exhibiting a Kd of 1.44 nM and Bmax of 0.20 mol of [3H]SK&F-107260/mol of alpha v beta 3. [3H]SK&F-107260 binding was inhibited by a variety of RGD-containing peptides and by the snake venom protein echistatin, whereas an RGE-containing peptide and four nonpeptide fibrinogen receptor (alpha IIb beta 3) antagonists failed to do so. This study shows that alpha v beta 3 exhibits distinct ligand specificity from the structurally homologous fibrinogen receptor, alpha IIb beta 3. The relative potencies of the RGD-containing peptides in inhibiting [3H]SK&F-107260 binding to alpha v beta 3 were the same as their relative potencies in inhibiting biotinylated-fibrinogen binding to the receptor. alpha v beta 3 purified from chicken osteoclasts and human placenta bound [3H]SK&F-107260 with similar affinities and displayed the same pharmacological profile as the platelet vitronectin receptor. The alpha v beta 3 antagonists inhibited the attachment of MG63 human osteosarcoma cells or rat osteoclasts to recombinant rat osteopontin. The rank order of potency of the antagonists in the cell adhesion assays was similar to that of the receptor binding assay, suggesting that the purified alpha v beta 3-[3H]SK&F-107260 binding assay is a valid reflection of the ligand binding to alpha v beta 3 on cell systems.
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PMID:Studies on alpha v beta 3/ligand interactions using a [3H]SK&F-107260 binding assay. 879 91

Treatment for osteosarcoma is problematic because there are no prognostic markers. Diagnosis is primarily limited to cytologic grading. Oncogenesis alters cell structure therefore osteoblast tissue matrix proteins (extracellular matrix, cytoskeletal, intermediate filament, and nuclear matrix proteins), components of the cell substructure, are candidates for osteosarcoma markers. Structural proteins of the extracellular matrix, e.g. the collagens, are useful for diagnosis but not for tumors that produce little osteoid. To identify principal cellular tissue matrix proteins that distinguish normal from transformed human osteoblasts, their expression in normal osteoblasts, two osteosarcoma cell lines, and three primary osteosarcoma tumors were compared. The tumors were graded as (i) intermediate, (ii) high, and (iii) high grade recurrent. The 1-D SDS/PAGE profiles of the major components of the nuclear matrix and intermediate filament fractions from normal osteoblasts did not vary with biopsy site, age, or sex of patients. These profiles included known cytoskeletal proteins and OB250, a approximately 250 kD protein(s) observed in the intermediate filament fraction. A loss of protein bands, including OB250, was observed in the osteosarcoma cell lines and tumors. The intermediate and high grade tumors exhibited nearly identical protein profiles including potential tumor-specific proteins and collagen, consistent with the presence of intracellular collagen fibers in osteosarcoma. A microsequence was obtained for OT25, a novel low molecular weight protein observed in osteosarcoma cell lines. Fibrinogen gamma-chain, a protein that mediates cell adhesion was recovered from the high grade recurrent tumor.
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PMID:Tissue matrix protein expression in human osteoblasts, osteosarcoma tumors, and osteosarcoma cell lines. 940 69

Adhesive properties of tenascin-X (TN-X) were investigated using TN-X purified from bovine skin and recombinant proteins encompassing the RGD sequence located within the tenth fibronectin type-III domain, and the fibrinogen-like domain. Osteosarcoma (MG63) and bladder carcinoma cells (ECV304) cells were shown to adhere to purified TN-X, but did not spread and did not assemble actin stress fibers. Both cell types adhered to recombinant proteins harboring the contiguous fibronectin type-III domains 9 and 10 (FNX 9-10) but not to the FNX 10 domain alone. This adhesion to FNX 9-10 was shown to be mediated by alphavbeta3 integrin, was inhibited by RGD peptides and was strongly reduced in proteins mutated within the RGD site. As antibodies against alphavbeta3 integrin had no effects on cell adhesion to purified TN-X, we suggest that the RGD sequence is masked in intact TN-X. Cell attachment to the recombinant TN-X fibrinogen domain (FbgX) and to purified TN-X was greater for MG63 than for ECV304 cells. A beta1-containing integrin was shown to be involved in MG63 cell attachment to FbgX and to purified TN-X. Although the existence of other cell interaction sites is likely in this huge molecule, these similar patterns of adhesion and inhibition suggest that the fibrinogen domain might be a dominant site in the whole molecule.
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PMID:Cell adhesion to tenascin-X mapping of cell adhesion sites and identification of integrin receptors. 1046 49

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


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