Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025202 (melanoma)
69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The hematopoietic cell recognition sites of human fibronectin (FN) are the Arg-Gly-Asp-Ser (RGDS) sequence recognized by widely distributed integrin receptor alpha 5 beta 1 and the type III connecting segment (III CS) containing two cell-binding sites, designated CS1 and CS5, that are recognized by the alpha 4 beta 1 receptor. The C-terminal heparin-binding domain of FN (Hep II) has recently been demonstrated to support adhesion of alpha 4 beta 1-dependent melanoma cells [A. P. Mould and M. J. Humphries (1991) EMBO J. 10, 4089-4095]. Previously we demonstrated that this region of FN mediated binding of FN to HL-60 cells (acute promyelocytic leukemia cell line) by direct interaction independently of RGD and CS1 [H. Fujita et al., (1995) Exp. Cell Res. 217, 484-488]. In this study we have characterized a novel site in the Hep II region for binding to HL-60 cells. alpha 4 beta 1 and alpha 5 beta 1 were expressed on HL-60 cells, while alpha 2 beta 1 and alpha 3 beta 1 were not present, as shown by flow cytometry using monoclonal antibodies specific for the different integrins. Anti-alpha 4 beta 1 (P4C2) and anti-beta 1 (JB1a) antibodies inhibited binding of a 29-kDa dispase-digestive fragment of FN to HL-60 cells. This fragment contains the C-terminal heparin-binding domain of FN but lacks CS1 and CS5. Only the peptide representing the sequence from Val1866 to Arg1880, designated E1, inhibited the binding of the 29-kDa fragment to HL-60 cells. The active region of this peptide was a sequence of Thr-Asp-Ile-Asp-Ala-Pro-Ser (TAI-DAPS), which is homologous to Leu-Asp-Val-Pro-Ser (LDVPS) derived from the active site of CS1. Furthermore, labeled E1 peptide directly bound to HL-60 cells. The anti-alpha 4 beta 1 antibody (P4C2) inhibited this interaction. These results indicate that the site of binding to hematopoietic cells is present in the Hep II region of FN and the definition of the chemical structure of FN clarifies a fundamental mechanism of cell invasion of the extracellular matrix.
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PMID:The novel recognition site in the C-terminal heparin-binding domain of fibronectin by integrin alpha 4 beta 1 receptor on HL-60 cells. 859 21

CD44-mediated cell adhesion to hyaluronate is controlled by mechanisms which are poorly understood. In the present work we examine the role of N-linked glycosylation and Ser-Gly motifs in regulating CD44-hyaluronate interaction. Our results show that treatment of a panel of human cell lines which constitutively express CD44 with the inhibitor of N-linked glycosylation tunicamycin results in the loss of attachment of these cells to hyaluronate-coated substrate. In contrast, treatment of the same cells with deoxymannojirimycin, which inhibits the conversion of high mannose oligosaccharides to complex N-linked carbohydrates, results in either no change or an increase in CD44-mediated adhesion to hyaluronate, suggesting that complex N-linked oligosaccharides may not be required for and may even inhibit CD44-HA interaction. Using human melanoma cells stably transfected with CD44 N-linked glycosylation site-specific mutants, we show that integrity of five potential N-linked glycosylation sites within the hyaluronate recognition domain of CD44 is critical for hyaluronate binding. Mutation of any one of these potential N-linked glycosylation sites abrogates CD44-mediated melanoma cell attachment to hyaluronate-coated surfaces, suggesting that all five sites are necessary to maintain the HA-recognition domain in the appropriate conformation. We also demonstrate that mutation of serine residues which constitute the four Ser-Gly motifs in the membrane proximal domain, and provide potential sites for glycosaminoglycan side chain attachment, impairs hyaluronate binding. Taken together, these observations indicate that changes in glycosylation of CD44 can have profound effects on its interaction with hyaluronic acid and suggest that glycosylation may provide an important regulatory mechanism of CD44 function.
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PMID:Glycosylation of CD44 is implicated in CD44-mediated cell adhesion to hyaluronan. 860 95

This study was conducted to determine the mechanisms for the enhanced inhibitory effect of cell-adhesive peptides conjugated to polyethylene glycol (PEG) on tumor metastasis. Tyr-Ile-Gly-Ser-Arg (YIGSR), a laminin-derived peptide, conjugated with amino-PEG (YIGSR-aPEG) inhibited lung metastasis of B16-BL6 melanoma cells more effectively than unconjugated YIGSR peptide. [125I]-YIGSR-aPEG and native [125I]-YIGSR showed similar biphasic elimination and profiles after intravenous injection into C57BL/6 mice. Both [125I]-YIGSR and [125I]-YIGSR-aPEG expressed similar plasma half-lives and organ distributions. The radioactivity of both compounds was transported rapidly from the blood to the kidneys, and immediately excreted into the urine. [125I]-YIGSR was almost completely degraded in the urine, but [125I]-YIGSR-aPEG was not. In an in vitro stability assay, [125I]-YIGSR was degraded immediately upon incubation with mouse serum, whereas [125I]-YIGSR-aPEG was not degraded after 180 min incubation in mouse serum. These findings indicate that the enhanced inhibitory effect of YIGSR-aPEG on lung metastasis might be due to its increased stability in the blood.
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PMID:Synthetic cell-adhesive laminin peptide YIGSR conjugated with polyethylene glycol has improved antimetastatic activity due to a longer half-life in blood. 862 Dec 71

Integrin alpha v beta 3 is distinct in its capacity to recognize the sequence Arg-Gly-Asp (RGD) in many extra-cellular matrix (ECM) components. Here, we demonstrate that in addition to the recognition of ECM components, alpha v beta 3 can interact with the neural cell adhesion molecule L1-CAM; a member of the immunoglobulin superfamily (IgSF). M21 melanoma cells displayed significant Ca(++)-dependent adhesion and spreading on immunopurified rat L1 (NILE). This adhesion was found to be dependent on the expression of the alpha v-integrin subunit and could be significantly inhibited by an antibody to the alpha v beta 3 heterodimer. M21 cells also displayed some alpha v beta 3-dependent adhesion and spreading on immunopurified human L1. Ligation between this ligand and alpha v beta 3 was also observed to promote significant haptotactic cell migration. To map the site of alpha v beta 3 ligation we used recombinant L1 fragments comprising the entire extracellular domain of human L1. Significant alpha v beta 3-dependent adhesion and spreading was evident on a L1 fragment containing Ig-like domains 4, 5, and 6. Importantly, mutation of an RGD sequence present in the sixth Ig-like domain of L1 abrogated M21 cell adhesion. We conclude that alpha v beta 3-dependent recognition of human L1 is dependent on ligation of this RGD site. Despite high levels of L1 expression the M21 melanoma cells did not display significant adhesion via a homophilic L1-L1 interaction. These data suggest that M21 melanoma cells recognize and adhere to L1 through a mechanism that is primarily heterophilic and integrin dependent. Finally, we present evidence that melanoma cells can shed and deposit L1 in occluding ECM. In this regard, alpha v beta 3 may recognize L1 in a cell-cell or cell-substrate interaction.
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PMID:Human neural cell adhesion molecule L1 and rat homologue NILE are ligands for integrin alpha v beta 3. 863 23

We studied the influence of 10 synthetic glycoamine analogs on colony formation in 0.3 and 0.9% agarose by metastatic human breast carcinoma (MDA-MB-435) and melanoma (TXM-13) cells. Nine synthetic analogs significantly inhibited the colony formation in 0.9% agarose of MDA-MB-435 human breast carcinoma cells; five compounds caused a 73-83% reduction of colony formation. Seven synthetic glycoamines caused a significant inhibition of colony formation in 0.9% agarose by TXM-13 melanoma cells with the inhibitory effect ranging from 71 to 87%. The 50% inhibition (I50) doses and relative activity rank of the compounds were similar for both breast carcinoma and melanoma cell lines. The murine B16 melanoma cell aggregation assay was employed to elucidate the potential mechanism(s) of the inhibitory activity of synthetic glycoamines. The relative activity ranks of the compounds based on the independently determined I50 doses for both cell aggregation and clonogenic growth assays were very similar for the four most active synthetic analogs and clearly indicated the importance of hydrophobic amino acid in mediating the bioactivity of synthetic glycoamines. In both experimental systems (clonogenic growth in agarose and cell aggregation assay) the leading compound was N-(1-deoxy-D-fructos-1-yl)-D-leucine (Fru-D-Leu) and the least active analog was N-(l-deoxy-D-fructos-1-yl)-glycine (Fru-Gly). These results show that synthetic glycoamines may act by competing for specific carbohydrate-lectin interactions, particularly those involving beta-galactoside-specific lectins expressed on metastatic cells.
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PMID:Inhibition of colony formation in agarose of metastatic human breast carcinoma and melanoma cells by synthetic glycoamine analogs. 867 80

Cytotoxicity indicated by increased release of prelabeled 51chromium (51Cr) and lactate dehydrogenase (LDH) was studied in human prostate cancer and melanoma cells in cell culture following irradiation or exposure to several injurious substances. These changes were compared to those observed in bovine aortic endothelial cells (BAEC) subjected to identical treatments. Further, the effect of irradiation on plasminogen activator (PA) secretion from prostate cancer cells, and the effect of glycine on radiation-induced cytotoxicity in BAEC were also investigated. Radiation, lipopolysaccharide and xanthine/xanthine oxidase stimulated no release of 51Cr or LDH from tumor cells, while these treatments induced a dose- and time-related loss of those cytotoxic indicators from BAEC. Protease, elastase and Triton X-100 incited loss of 51Cr and LDH from all three cell types. Radiation, lipopolysaccharide and xanthine/xanthine oxidase have been shown to cause cell injury via a common pathogenic pathway of oxidant generation. Tumor cells appear quite resistant to oxidant stress. Cell damage precipitated by protease, elastase and Triton probably involves hydrolysis of proteins and phospholipids in the cell membrane, leading to an increased leakage of intracellular proteins such as LDH and those bound with 51Cr. Radiation caused a dose- and time-related reduction in the secretion of PA from prostate cancer cells. PA is alleged to play a role in tumor metastasis; the reduced secretion could be another beneficial effect of radiation, in addition to interruption of cell proliferation, in the impediment of tumor growth and spread. Glycine diminished cytotoxic injury of BAEC inflicted by radiation. This amino acid may prove useful in offering a degree of protection of normal tissue against radiation associated side-effects.
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PMID:Injury-specific cytotoxic response of tumor cells and endothelial cells. 868 34

A new compound containing the cell-adhesive Arg-Gly-Asp-Ser (RGDS) peptide was synthesized, i.e. tetrahydrofurantetracarboxylic acid (THFTCA)-RGDS conjugate [THFTCA- (RGDS)3, FC-243], and the inhibitory effect of FC-243 on lung metastasis of B16-BL6 melanoma in mice was examined in combination with or without the anticancer agent doxorubicin (DOX). FC-243 showed an inhibitory effect on lung metastasis of melanoma cells in a dose-dependent manner. A mixture of THFTCA and RGDS peptide or THFTCA alone did not show any inhibitory effect on experimental lung metastasis as compared with FC-243 on a molar basis. RGDS peptide, however, required a higher dose to obtain a sufficient antimetastatic effect. Intermittent IV administration of FC-243 after the inoculation of B16-BL6 cells caused significant inhibition of spontaneous lung metastasis as compared with multiple administration of RGDS or untreated control. The in vitro tumor invasion study showed that FC-243 as well as RGDS+THFTCA on a molar basis resulted in similar inhibition of the invasion of B16-BL6 cells into reconstituted basement membrane Matrigel. Combined treatment with FC-243 and DOX significantly inhibited lung metastasis of melanoma as compared with either treatment alone or the untreated control. Administrations of FC-243 and DOX in combination substantially prolonged the survival time of mice. These results demonstrate that combination therapy of the anti-cell adhesive FC-243 and the anticancer agent DOX, i.e. antiadhesion therapy and chemotherapy, is a new approach that offers enhanced inhibitory effects on tumor metastasis and invasion.
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PMID:Combination of anti-cell adhesive synthetic Arg-Gly-Asp-Ser analogue and anticancer drug doxorubicin heightens their original antimetastatic activities. 874 97

Malignant melanoma is increasing in incidence, and, though early lesions are readily treatable, systemic therapy for metastatic disease remains disappointing. Integrins are a family of cell-surface molecules that mediate adhesion between the cell and the extracellular matrix. One member of the integrin family, the alpha v beta 3 integrin, is associated with progression of melanomas, in that the most malignant cells express the highest levels of alpha v beta 3. Like many members of the integrin family, alpha v beta 3 recognizes the sequence Arg-Gly-Asp (RGD) in its ligands, and other molecules that contain this sequence will complete with the natural ligands (such as vitronectin) for binding. There is growing evidence that integrins function as receptors for signal transduction, and that integrin-mediated signalling can affect cell behaviour and even cell survival. Under certain circumstances, loss of integrin-mediated signalling will induce apoptosis, or programmed cell death, and we have demonstrated that melanoma cells treated with a cyclic peptide with high affinity for the alpha v beta 3 integrin will undergo apoptosis within three days. This mechanism might be exploited therapeutically.
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PMID:Adhesion molecules in melanoma--more than just superglue? 877 38

Osteopontin (OPN) is an integrin-binding secreted protein that contains an Arg-Gly-Asp (RGD) amino acid sequence and binds to various cell types via RGD-mediated interaction with the alpha v beta 3 integrin. We have identified a cell line whose binding to OPN does not require RGD or alpha v interactions. We compared the ability of two murine cell lines, L929 fibroblastic cells and B16-BL6 melanoma cells, to interact with OPN (from human milk, and recombinant human and mouse OPN) as well as recombinant OPN prepared to include either the N-terminal or C-terminal halves but lacking the RGD sequence. Both cell lines adhered to GRGDS peptides coupled to BSA, and these interactions were inhibited by addition of GRGDS (but not GRGES) peptides or a monoclonal antibody specific to the alpha v integrin subunit. Adhesion of L929 cells to OPN was also dependent on the RGD sequence and the alpha v integrin subunit. However, the binding of B16-BL6 cells was not inhibited by either GRGDS peptides or the anti-alpha v antibody. B16-BL6 (but not L929) cells were also able to adhere to and spread on both N-terminal and C-terminal OPN proteins that lack the RGD sequence, and these interactions were not inhibited by either GRGDS peptides or anti-alpha v antibody. Together these results indicate that B16-BL6 cells can adhere to OPN by interactions that are independent of either the RGD sequence or the alpha v integrin subunit, and suggest that some cells can interact with additional, non-RGD binding sites in OPN.
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PMID:Non-RGD domains of osteopontin promote cell adhesion without involving alpha v integrins. 883 81

The low affinity p75 neurotrophin receptor (p75NTR) is a cysteine-rich transmembrane glycoprotein which is frequently overexpressed in advanced stages of human melanoma. The biological consequences of this overexpression are unknown; however, it has recently been shown that p75NTR can enhance the invasive potential of melanoma cells in vitro. In the present study we examined cell lines established from normal human melanocytes and metastatic melanomas for expression of p75NTR mRNA and protein. The results showed that, compared with normal melanocytes, levels of p75NTR-specific protein were high in seven melanoma lines, markedly decreased in two melanoma lines and comparable in two melanoma lines. The conserved transmembrane domain of p75NTR was analysed for point mutations by single strand conformation polymorphism analysis and direct DNA sequencing. Identical point mutations were detected in the transmembrane domain of p75NTR in the two melanoma lines with reduced p75NTR protein expression, which resulted in the substitution of the uncharged amino acid Gly for the negatively-charged Asp.
Melanoma Res 1996 Oct
PMID:Mutation and expression of the low affinity neurotrophin receptor in human malignant melanoma. 890 97


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