Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001511 (Adhesion)
 5,955 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A panel of monoclonal antibodies (mAbs) to bovine fibronectin (FN) is described which modulates either heparin binding or cell adhesion to FN, or both. A combination of competitive exclusion and binding to proteolytic fragments identified epitopes in the Hep II, Hep III/I and CBF (cell binding fragment) regions of FN. mAb A17, which bound to the CBF region, strongly inhibited the cell adhesion of BHK-21 fibroblasts, primary corneal fibroblasts and endothelial cells, and NM4 mammary adenocarcinoma cells, to FN at mAb concentrations as low as 1 microgram/ml. This mAb was not so effective at inhibiting the adhesion of B16 mouse melanoma cells. Adhesion of B16 cells to FN was more sensitive to inhibition by mAbs binding to Hep II (A2, A9, A32, A35). Of these, A32 and A35 significantly increased the binding of 35S-heparin to FN, whereas A2 and A9 did not affect it. mAbs A2, A9 and A32 showed good binding to HBF, the 40 kDa proteolytic fragment of human FN which contains both Hep II and IIICS (type III connecting segment). These mAbs inhibited B16 cell adhesion to the HBF (heparin binding fragment) by 30-50%, the greatest inhibition being shown by mAb A32. Two synthetic peptides from the HBF, CS1 (peptide 1) from the IIICS region and peptide I from the Hep II region, also inhibited B16 cell adhesion to HBF by approximately 70 and 30%, respectively. These results suggest that maximal cell adhesion to the HBF involves both CS1 and Hep II. The inhibitory effects of the two peptides were linearly additive in combination, whereas the inhibitory mAbs A2, A9 and A32 showed synergistic additive effects with each of the peptides. This points to the existence of an additional important cell binding site in Hep II, other than peptide I. Recent independent evidence for an additional cell binding site in Hep II supports this view. Melanoma cellular receptor(s) for the Hep II region may be cell surface proteoglycans but do not appear to bind to areas of Hep II with high affinity for soluble heparin, as the latter was not an inhibitor of B16 cell adhesion to the HBF. The increased effectiveness of A32 in inhibiting cell adhesion, compared to A2 and A9, may be due to conformational effects which increase the binding of soluble heparin, but reduce affinity for the cellular receptor. These results are discussed in context with other reports in the literature.
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PMID:Anti-fibronectin antibodies that modify heparin binding and cell adhesion: evidence for a new cell binding site in the heparin binding region. 138 58

Adhesion molecules are likely to play a role in the process of tumour progression. We investigated the expression of integrins, ICAM-1, and CD44 and the influence of interferon-alpha (IFN-alpha), interferon-gamma (IFN-gamma), and tumour necrosis factor-alpha (TNF-alpha) on expression of these molecules on four uveal melanoma cell lines. The in vitro integrin expression was quite variable. The alpha V and beta 1 subunits were expressed on all cell lines, and none of the cell lines showed any alpha 3, beta 2, or beta 4 expression. Other integrin subunits showed a more variable pattern. ICAM-1 and CD44 were strongly expressed on all cell lines. IFN-alpha, IFN-gamma, and TNF-alpha upregulated alpha 1, alpha 2, and alpha 3 expression, and did not alter alpha 4, alpha 5, alpha 6, beta 2, alpha v beta 3, and beta 4 expression. The effects on alpha V and alpha V beta 5 were variable. ICAM-1 was upregulated by IFN-gamma and TNF-alpha, but not by IFN-alpha. Cytokine treatment hardly changed CD44 expression. In one case a comparison was made between expression on cultured cells and on tissue sections of the tumour of origin. Differences in expression were observed for the integrin subunits alpha 2, alpha 3, and alpha 5. This study shows that integrins and ICAM-1 expression on uveal melanoma cells in vitro are susceptible to cytokine treatment, but that the effects on integrin expression are cytokine and cell line dependent. Furthermore, some differences in integrin expression between cells in vivo and in vitro exist.
Melanoma Res 1995 Aug
PMID:Cytokine-mediated modulation of integrin, ICAM-1 and CD44 expression on human uveal melanoma cells in vitro. 749 58

E- and P-cadherin are calcium (Ca2+)-dependent cell adhesion molecules important in the morphogenesis and maintenance of skin structure. By use of flow cytometry and specific antibodies, we now show that cultured human melanocytes express E- and P-cadherin on their surfaces, and that these molecules have the same characteristics as reported for other cell types. Specifically, melanocyte cadherins are sensitive to trypsin digestion in the absence of Ca2+ and are protected from trypsin degradation by Ca2+, and are functional at 37 degrees C but not at 4 degrees C. We further show that melanocytes contain mRNA transcripts encoding both E- and P-cadherin. Adhesion of cultured melanocytes to keratinocyte monolayers is abolished by pre-treatment of the melanocytes with trypsin/EDTA, which degrades E- and P-cadherins, is greatly reduced by anti-E-cadherin antibodies and is slightly reduced by antibodies to P-cadherin, alpha 2, alpha 3 and beta 1 integrins. In contrast to normal melanocytes, eight of nine melanoma cell lines lacked E-cadherin (or expressed markedly reduced levels) and five were negative for P-cadherin. Melanoma cells also failed to adhere to keratinocyte monolayers. These results demonstrate that normal human melanocytes express functional E- and P-cadherin and that E-cadherin is primarily responsible for adhesion of human melanocytes to keratinocytes in vitro. In addition, transformed melanocytes express markedly reduced levels of E- and P-cadherin, and exhibit decreased affinity for normal keratinocytes in vitro, suggesting that loss of cadherins may play a role in melanoma metastasis.
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PMID:E-cadherin is the major mediator of human melanocyte adhesion to keratinocytes in vitro. 805 51

Our previous studies have shown that a peptide corresponding to the residue sequence 185-203 of the NC1 domain of the alpha3 chain of basement membrane collagen (type IV) inhibits the activation of polymorphonuclear leukocytes. Peptides from the same region of the alpha1, alpha2, alpha4, and alpha5(IV) chains did not exhibit this property. Because of the intimate relationship between metastasizing neoplastic cells and vascular as well as epithelial basement membranes, we measured the cell adhesion-promoting activity of peptides from the NC1 domain of type IV collagen and their effect on proliferation of human melanoma cells. We found that peptide alpha3(IV)185-203 (CNYYSNSYSFWLASLNPER) not only promotes adhesion of human melanoma cells but also inhibits their proliferation. Adhesion increased by 50-60% over control. Melanoma cell proliferation was inhibited by 40% when cells were grown in a medium containing 5 microg/ml peptide for 5 days. Studies showed that replacement of serine in position 189 or 191 by alanine resulted in significantly reduced adhesion. Similarly, serine replacement resulted in reduced ability to inhibit proliferation. Our data suggest that a region of the NC1 domain of the alpha3(IV) chain, contained within the sequence 185-203, not only specifically promotes adhesion but also inhibits proliferation of melanoma cells. These properties appear to be dependent on the presence of the triplet sequence -SNS- (residues 189-191), which is unique to the alpha3 chain and may represent an important functional epitope.
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PMID:A cell binding domain from the alpha3 chain of type IV collagen inhibits proliferation of melanoma cells. 925 46

Recent advancement in the research of malignant melanoma is reviewed. Among many gene alterations detected in human melanoma, defect of CDKN2A located at chromosome 9p21 seems to be most important in the earlier developmental phase, though significance of this gene in the evolution of melanoma in situ has not been confirmed yet. Deletions of PTEN/MMAC1 on 10q23.3 and AIM1 on 6q21 as well as mutations of ras gene are involved in the later progression stages of melanoma. Adhesion molecules relevant to development and progression of melanoma have been intensely investigated in recent years, revealing crucial roles of cadherins and alpha(v)beta(3) integrin in the biologic behaviors of melanoma cells. Melanoma is characterized by extremely high potential of developing metastases. Dynamic changes of matrix metalloproteinase activity during invasion and movement of melanoma cells may be a major concern in this field. Fragility of blood vessels in melanoma lesions is another important point related to hematogeneous metastases. Acral lentiginous melanoma is a unique subtype of melanoma, because, in contrast to other subtypes, ultraviolet irradiation is not a major factor in its development. Investigation of pathogenesis of acral lentiginous melanoma surely provides us with new information about mechanism of melanocyte transformation. Recent advances in the management of malignant melanoma are also briefly reviewed, such as biochemotherapy, immunotherapy, and gene therapy. Finally, the concept of molecular classification of melanoma by gene expression profile is introduced, which possibly enables us to give the tailor-made therapy for each melanoma patient in the near future.
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PMID:Recent advances in melanoma research. 1132 15

An Intracellular Adhesion Molecule I (ICAM-1) immunoassay from R and D Systems, and a Melanoma Inhibitory Activity (MIA) immunoassay from Roche Diagnostics were tested for accurate quantitation within complex biological substances such as cell lysates. Prior to assay, lysates of melanoma cells were treated with detergents to obtain soluble antigens. Maximum ICAM-1 and maximum MIA were detected after treatment using 0.8% Triton X-100. Two key aspects of assay accuracy were: 1) determining the dilutions of test sample that provided accurate quantitation (sample range), and 2) performing spiking experiments at these dilutions to determine absence or presence of a "matrix" effect due to biological complexity of the sample. A high degree of accuracy was found by diluting this particular cellular extract 50-fold prior to ICAM-1 assay, or only 5-fold prior to MIA assay. In addition, the bicinchoninic acid protein assay was analyzed to test the accuracy of protein quantitation of cellular lysates. Precision, limits of detection, and quantitation, robustness, linearity, and specificity also were tested for the immunoassays.
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PMID:Adaptation of commercial immunoassays to analysis of complex biological substances. 1184 98

Collagen is a multifunctional protein, serving as a structural scaffold and a modulator of cellular responses. Prior work has identified distinct regions from several collagen types that promote cell adhesion, spreading, migration, and signal transduction. One of these regions, alpha1(IV)1263-1277 from type IV collagen, mediates these responses via melanoma cell CD44-chondrotin sulfate proteoglycan receptors. In the study presented here, we have used a triple-helical model of alpha1(IV)1263-1277 to evaluate (a) conformational stability and (b) cellular responses based on single-site incorporation of trans-4-fluoro-L-proline (trans-Flp) or cis-4-fluoro-L-proline (cis-Flp) for trans-4-hydroxy-L-proline (trans-Hyp). The structural effects of cis-Flp and trans-Flp substitution were studied by circular dichroism and NMR spectroscopies. The peptide containing a single trans-Flp instead of trans-Hyp was slightly more thermally stable than the parent peptide (T(m) = 37 vs 34 degrees C), while the peptide containing cis-Flp was considerably less stable than the parent peptide (T(m) = 30 degrees C). Melanoma cell adhesion and spreading were examined under conditions where the trans-Hyp-, trans-Flp-, and cis-Flp-containing ligands were approximately 15, <10, and approximately 65% denatured, respectively. Adhesion to each of the three ligands was remarkably sensitive to the respective ligand conformation, with EC(50) values of approximately 2.5, approximately 0.35, and >5.0 microM for the trans-Hyp-, trans-Flp-, and cis-Flp-containing ligands, respectively. Melanoma cell spreading was quantitated over a ligand concentration range of 0.01-50 microM and, in a fashion similar to adhesion, was more extensive on the trans-Flp ligand than on the trans-Hyp ligand. Very low levels of spreading were observed with the cis-Flp-containing ligand at all concentrations tested. Melanoma cell adhesion to and spreading on the three ligands suggested the dramatic biological consequence of even subtle changes in relative triple-helical content. Such subtle changes may model those occurring in the basement membrane during the tumor cell invasion process, and thus provide mechanistic insight into this stage of metastasis.
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PMID:Modulation of triple-helical stability and subsequent melanoma cellular responses by single-site substitution of fluoroproline derivatives. 1199

Adhesion between the CD44s receptor and hyaluronic acid plays an important role in cell migration, tumour growth and progression. Although the alternative splicing of CD44 variant exons represents the principal regulatory mechanism of CD44-mediated functions, CD44v spliced variants are scantily expressed in melanoma cells. For this reason, we have investigated the possibility that post-translational modifications of the CD44 standard receptor could play a pivotal role in regulating CD44-mediated functions in melanoma. Using metabolic inhibitors of N- and O-glycosylation, as well as melanoma transfectants expressing CD44s O-glycosylation site-specific mutants, we performed structural and functional analysis of N- and O-deglycosylated CD44s molecules expressed in melanoma cells. We discovered that complete N- and O-glycosylation is not required by CD44s to be correctly expressed on the melanoma cell surface. Indeed, variably glycosylated and functionally different CD44s molecules were constitutively expressed in primary and metastatic lesions. Furthermore, we observed that changes in N- and O-glycosylation of CD44s could modulate its cleavage. In fact, spontaneous CD44s shedding was dependent on the presence of partial or complete O-glycosylation of four serine-glycine motifs localized in the membrane-proximal CD44 ectodomain. Mutation of these serine residues, as well as an extensive metabolic O-deglycosylation, strongly impaired spontaneous CD44 shedding. Furthermore, an O-glycosylation-independent mechanism of CD44 cleavage has been identified. This alternative mechanism of receptor cleavage is phorbol 12-myristate-13-acetate (PMA) inducible, mediated by metalloproteinase and requires the presence of N-linked sugar residues. Our findings demonstrate that the post-translational modification of CD44s represents the principal regulatory mechanism of CD44s-mediated functions in melanoma.
Melanoma Res 2003 Aug
PMID:CD44s adhesive function spontaneous and PMA-inducible CD44 cleavage are regulated at post-translational level in cells of melanocytic lineage. 1288 58

Osteonectin is recognised as a marker of metastasis progression in melanoma and has been implicated in the transition from radial to vertical growth phase. A Tetracycline-inducible system was used to regulate Osteonectin protein levels in melanoma cell lines to examine the morphological, biochemical and invasive changes that accompany its altered expression. Assay of protein and phosphorylation changes showed a downregulation of E-cadherin, upregulation of Osteopontin and a corresponding increase in phosphorylation of Focal Adhesion Kinase on Tyr(397) and Tyr(576) concomitant with Osteonectin induction. Melanoma cells overexpressing Osteonectin displayed increased invasive potential, whereas ablation of Osteonectin gene transcription using siRNA suppressed the invasive potential of these cells and resulted in the upregulation of E-cadherin. The recently described interaction of Osteonectin with Integrin Linked Kinase leading to modulation of its activity suggests a mechanism relevant to the loss of E-cadherin and cell adhesion that occurs during melanoma progression. These results indicate a central role for Osteonectin in the regulation of gene expression changes driving the progression of melanoma toward metastasis.
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PMID:Osteonectin downregulates E-cadherin, induces osteopontin and focal adhesion kinase activity stimulating an invasive melanoma phenotype. 1772 18

Melanoma is becoming increasingly common in recent years and has a very high mortality rate, owing largely to its highly metastatic nature. It tends to metastasize early in the course of the disease, and after metastasis is resistant to most current therapies. Preclinical data has indicated that heparin administered to patients as an antithrombotic treatment also has anti-metastatic properties. Heparin has been shown to interfere with the binding of the integrin Very Late Antigen 4 (VLA-4) to its ligand Vascular Cell Adhesion Molecule 1 (VCAM-1) and in a recent paper the laboratory of Bendas (Thrombosis and Haemostasis, Prepublished online) demonstrated that CCN1 binds to VLA-4 and interference in this binding by heparin results in reduced strength of the VLA-4/VCAM-1 binding. This indicates that CCN1 might represent a good target for reducing the metastasis, and thus mortality, of melanoma.
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PMID:CCN1 is a novel target to reduce the metastasis of melanoma. 2419 93


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