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)

Adhesion of myeloid leukemia cells to the bone marrow (BM) microenvironment is mediated in part by Beta 1 and Beta 2 integrins. Cells of the erythroleukemia line K562, derived from a patient with chronic myeloid leukemia, bind to BM fibroblasts (BMFs) but the adhesion cannot be accounted for by integrins or other known adhesion proteins including CD44 or members of the Ig or selectin families. Membrane fragments from K562 cells were radioiodinated and allowed to adhere to BMF monolayers. Adherent proteins were solubilized together with the fibroblasts, analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and visualized by autoradiography. Four adherent proteins were consistently observed. Two of these, with reduced molecular weights of 52 kD and 35 to 37 kD, were prominent. Addition of soluble thrombospondin and heparin but not fibronectin inhibited binding of K562 membrane proteins to adherent BMFs and immobilized thrombospondin- and heparin-bound K562 proteins. The 52-kD protein has a multimeric structure nonreduced and has characteristics of a glycoprotein. Its adhesion to fibroblasts is divalent cation and temperature sensitive. The 35- to 37-kD protein, whose function is divalent cation but not temperature sensitive, is phosphoinositol-linked and has characteristics identical to an adherent 35- to 37-kD protein identified on murine progenitor cells. Membrane preparations from two cases of acute myeloid leukemia showed an adherent 35- to 37-kD protein and in one case an adherent 52-kD protein without other adherent bands. A K562 subclone with reduced adherence to BMFs showed reduced amounts of adherent 52-kD and 35- to 37-kD proteins. These proteins may be responsible for the adhesion of malignant and normal hematopoietic progenitor cells to the BM microenvironment.
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PMID:Identification of novel K562 membrane proteins that adhere to bone marrow fibroblasts. 870 84

Despite the relatively early reconstitution of blood B-lymphocyte counts observed in patients treated with bone marrow transplantation (BMT), these patients undergo a prolonged phase of humoral immunodeficiency. Adhesion molecules perform relevant functions in many cell types. The present study examines the expression of several adhesion molecules on human B lymphocytes newly formed after BMT. Blood B cells from 38 patients were studied by flow cytometry and three-color analysis. Blood CD5- B lymphocytes obtained at an early stage after BMT (2 to 4 months) showed a markedly low expression of the adhesion molecules CD54, CD44, CD11a, and CD62L. However, these cells exhibited a normal expression of other molecules including CD29, CD19, CD20, and DR. This deficiency was progressively corrected, reaching normal levels in the late post-BMT period (12 to 15 months). In contrast, CD54, CD44, CD11a, and CD62L expression on the patients' CD5+ B lymphocytes was found to be consistently normal. Deficient adhesion molecule expression on CD5- B cells in the early post-BMT period was similarly observed in patients treated with either an allo-BMT (n = 24) or an auto-BMT (n = 14). Because the post-BMT period mimics normal ontogeny, adhesion molecule expression was also investigated in cord-blood B lymphocytes. Cord-blood CD5- B lymphocytes, in contrast to CD5+, also expressed CD54, CD44, CD11a, and CD62L at levels much lower than those found in normal adults. Present data suggest that progressive expression of CD54, CD44, CD11a, and CD62L seems to be a part of the maturational program of CD5- B lymphocytes during both post-BMT and normal development periods. This observation may help to explain the humoral immunodeficiency observed in both conditions.
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PMID:Deficient expression of adhesion molecules by human CD5- B lymphocytes both after bone marrow transplantation and during normal ontogeny. 878 29

Adhesion molecules play important roles in immune reactions and inflammatory processes and may constitute attractive targets for immunomodulatory approaches. In this study, blocking mAbs against a series of adhesion molecules were tested for their therapeutic effect on developing arthritis in a mouse model. MAbs were given for a period of 4 weeks at the time of exspected incidence of visible disease symptoms, i.e. 4 weeks after priming with collagen type II. A significant reduction of incidence down to values of 13% and 29% of the controls was obtained with mAbs against CD44 and alpha 4-integrin, respectively, during an observation time of 13 weeks. MAbs against CD4 and LFA-1 resulted only in weaker, non-significant effects or a delay in the incidence. MAbs against other molecules including L-selectin, ICAM-1 or VCAM-1 were not effective. The development of antibodies against collagen type II, collagen type I, proteoglycans and the immunogen, bovine collagen type II was affected by mAb treatment to a different extent. In this case, the anti CD4 mAb was the most effective, followed by the anti alpha 4-antibodies in most cases, whereas anti CD44 showed less clear effects on the development of humoral responses. In a skin delayed type hypersensitivity model analyzed for comparison, mAbs against LFA-1/ICAM-1 and alpha 4-integrin showed the largest effects on ear swelling. These data show that mAbs against several adhesion molecules are able to block selectively distinct aspects of immune reactions, and that CD44 and alpha 4-integrins could be promising targets for an immunotherapy of rheumatoid arthritis with receptor-interfering agents.
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PMID:Therapeutic effects of antibodies against adhesion molecules in murine collagen type II-induced arthritis. 885 15

Our previous studies have suggested that the interaction between hyaluronic acid (HA) on peritoneal mesothelial cells and the membrane adhesion molecule, CD44, on ovarian tumour cells could be important in ovarian cancer metastasis. In order to study this further, adhesion of six ovarian tumour lines to HA coated on to a plastic surface was investigated. Four lines bound to the HA coat and two lines did not. The adhesive lines were those that expressed high amounts of CD44, but the degree of adhesion was not closely correlated with CD44 expression. The results suggested that different tumour lines had different affinities for HA. Treatment of the HA coat with hyaluronidase substantially reduced adhesion. Adhesion was also partially reduced if the tumour cells were preincubated with either soluble HA, or anti-CD44 antibodies directed against the HA binding region. An antibody against a non-HA binding region only slightly blocked adhesion at high antibody concentrations. Only the CD44H isoform was detected by immunoprecipitation on the tumour cells. These results suggest that ovarian tumour cells can attach to immobilised HA via CD44H on the cell membrane.
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PMID:Human ovarian tumour cells can bind hyaluronic acid via membrane CD44: a possible step in peritoneal metastasis. 887 6

Adhesion receptors on the surface of cancer cells play an important role in tumor cell migration, invasion, and metastasis. A number of specific cell surface-associated molecules that mediate cell-matrix and cell-cell interactions have been characterized, including the family of integrin receptors, the cadherins, the immunoglobulin (IgG) superfamily, a 67-kDa laminin-binding protein, and the CD44 receptor. Changes in the expression and function of these adhesion molecules are important characteristics in the development of gastrointestinal malignancies and might be used in the future as prognostic factors or as new targets in diagnosis and therapy. In esophageal cancer a downregulation of the E-cadherin receptor and the cytoplasmic protein alpha-catenin is associated with tumor dedifferentiation, infiltrative growth, and lymph node metastasis. In gastric cancer a reduction of E-cadherin expression due to gene mutations is restricted to diffuse-type tumors. The occurrence of the CD44 standard and the CD44-9v isoform on the surface of gastric cancer cells is significantly related to a higher tumor-induced mortality and a shorter survival time. The CD44-6v isoform is predominantly expressed by intestinal-type gastric carcinomas giving these tumor cells the ability to metastasize in the lymph nodes. In pancreatic cancer the expression of integrin adhesion receptors is significantly altered during the malignant transformation of the pancreatic tissue while a loss of the E-cadherin receptor can generate dedifferentiation and invasiveness of pancreas carcinoma cells. There is increasing evidence that integrin receptors and different isoforms of the CD44 receptor are altered following the malignant transformation of colonic mucosa into adenomas and invasive carcinomas and thus influencing in their metastatic potential. The expression of the CD44-6v isoform seems to be associated with an adverse prognosis in colorectal cancer due to the development of tumor metastases. A strong correlation could be observed between the expression of the 67-kDa laminin receptor and the degree of differentiation, the invasive phenotype, and the metastatic abilities of colorectal cancer cells. Analyzing the expression of the E-cadherin receptor in colorectal carcinomas it has been shown that this receptor may serve as an independent prognostic marker in Dukes' stage Colon cancer to identify patients with poor prognosis and designate them for adjuvant therapy after curative surgical treatment.
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PMID:Adhesion receptors in malignant transformation and dissemination of gastrointestinal tumors. 889 33

Biochemical and molecular genetic studies have contributed to our molecular knowledge of blood group-associated molecules in the past few years. Among the 23 blood group systems presently identified, almost all have a molecular basis and present investigations are oriented towards the analysis of genetic polymorphisms, tissue-specific expression and structure-function relationships. Antigens defined by carbohydrate structures, among which ABO, Hh, Lewis and Secretor are the main representative species, are indirect gene products. They are synthesized by Golgi-resident glycosyltransferases, which are the direct products of the blood group genes. Many of these enzymes have been cloned and the molecular basis of the silent phenotypes, for instance 0, Bombay/paraBombay, Le(a-b-) and non-secretor, has been elucidated. However, the glycosyltransferases involved in the biosynthesis of Pk, P and P1 antigens are not yet characterized. A large number of blood group antigens carried by red cell polypeptides expressed at the cell surface are not related to a carbohydrate structure, and these proteins are direct blood group gene products. Most have been cloned and characterized recently, for instance MN antigens (glycophorin A), Ss antigens (glycophorin B), Gerbich antigens (glycophorins C and D) and antigens encoded by the RH, LW, KEL, FY, JK, XG, LU and XK loci. Other antigens have been located on proteins already identified, for instance the Cromer antigens on DAF, Knops antigens on CR1, Indian and AnWj antigens on CD44, Yt antigens on AChE, Diego, Wr, Rga and Warr on Band 3, Colton antigens on AQP-1 (water channel). The SC (Scianna) et DO (Dombrock) systems, however, still resist to molecular cloning. On the basis of this information, a tentative classification of blood group antigens into five functional categories is emerging: - Transporters and channels, - Receptors and ligands, - Adhesion molecules, - Enzymes, - Structural proteins. This review will focus on these recent findings and will illustrate how these studies may bring new information for analysis of normal and abnormal phenotypes and for understanding both the mechanisms of tissue specific expression and the potential function of these antigens, particularly those expressed in non-erythroid lineage. In addition, since our knowledge of the molecular basis of blood group polymorphisms has significantly increased, new genotyping techniques potentially useful in clinical applications will become available.
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PMID:[A molecular approach to the structure, polymorphism and function of blood groups]. 892 12

Adhesion receptors can serve as primary signal transduction molecules that convey information into cells that can affect cell proliferation and differentiation. Since hematopoietic progenitors adhere to marrow stroma and fibronectin via the alpha 4 beta 1 integrin and CD44, we examined the role of these receptors in the transfer of proliferation-regulatory signals to progenitors. Actively proliferating colony-forming cells (CFCs) present in cultured CD34+ cells were incubated with mouse monoclonal antibodies against the alpha 4, beta 1, or CD44 receptors and crosslinking was performed with a secondary goat-anti-mouse antibody. The effect on CFC proliferation was examined with a 3H thymidine suicide assay. Compared with controls (39 to 51% kill), crosslinking the alpha 4 or beta 1 integrins significantly reduced CFC proliferation (12 to 26% kill, p = 0.01), indicating that proliferation-inhibitory signals are transmitted through the VLA-4 integrin. Cytochalasin D, a compound that prevents actin polymerization, prevented not only alpha 4 receptor capping, but also the inhibition of CFC proliferation observed following alpha 4 crosslinking. However, crosslinking of the CD44 receptor with the antibodies Hermes-3 and 50B4, which inhibit adhesion of CFC to fibronectin, failed to cap the CD44 receptor in the majority of CD34+ cells. Furthermore, crosslinking of the CD44 receptor with these antibodies also failed to inhibit proliferation of CFCs. These studies demonstrate that adhesion receptor crosslinking of the alpha 4 beta 1 integrin, together with subsequent changes in F-actin polymerization, negatively regulates hematopoietic progenitor proliferation in a manner independent of the shape change associated with adhesion.
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PMID:Monoclonal antibody crosslinking of the alpha 4 or beta 1 integrin inhibits committed clonogenic hematopoietic progenitor proliferation. 913 Oct 7

Adhesion of normal colony-forming cells (CFC) to bone marrow (BM) stroma and the extracellular matrix (ECM) component fibronectin (FN) depends at least in part on the alpha4beta1 and alpha5beta1 integrins and the CD44 receptor. Aside from anchoring progenitors in the marrow microenvironment, beta1 integrin-dependent adhesion of normal CFC is associated with inhibition of their proliferation. In contrast to normal CFC, chronic myelogenous leukemia (CML) Ph+ CFC adhere significantly less to either stroma or FN. CML Ph+ CFC proliferation is also not inhibited by coculture with stroma or FN. However, equal numbers of alpha4, alpha5, and beta1 integrins and CD44 are present on CML and normal CD34+ cells. We have previously demonstrated that beta1-dependent adhesion to and subsequent proliferation inhibition by FN can be restored when CML Ph+ CFC are incubated with the beta1 integrin activating antibody, 8A2, and demonstrated a role for the alpha5beta1 integrin in this phenomenon. Since the integrin alpha4beta1 and the proteoglycan form of CD44 may cooperate in establishing normal CFC adhesion to FN, we examined if treatment of CML Ph+ CFC with 8A2 also restores the cooperativity between beta1 integrins and CD44. We demonstrate that 8A2 induces adhesion of CML Ph+ CFC not only to intact FN but also to alpha4beta1, alpha5beta1, and proteoglycan binding fragments of FN. 8A2-induced adhesion to these fragments and peptides also results in a significant inhibition of the proliferation of CML Ph+ CFC. Addition of antibodies to either the alpha5, alpha4, or beta1 integrins, antibodies against the CD44 receptor, or removal of chondroitin sulfate glycosaminoglycans from the surface of CML CD34+ HLA-DR+ cells significantly reduced the 8A2-induced adhesion to and adhesion-mediated inhibition of proliferation by FN. These studies demonstrate that activation of beta1 integrins on CML Ph+ CFC not only results in upregulation of beta1 integrin-dependent adhesion and adhesion-mediated inhibition of proliferation, but also in the restoration of cooperation between beta1 integrins and CD44. These studies suggest that decreased beta1 integrin avidity may also affect the function of the proteoglycan adhesion receptor CD44, both of which may contribute to the abnormal circulation and expansion of malignant progenitors in CML.
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PMID:Activation of beta1 integrins on CML progenitors reveals cooperation between beta1 integrins and CD44 in the regulation of adhesion and proliferation. 917 35

Peritoneal carcinomatosis involves a series of events including tumor cell interactions with mesothelial cells and the extracellular matrix (ECM). We have studied the adhesive and invasive properties of four human colorectal carcinoma cell lines (Co115, HT29, SW480, SW620) confronted in vitro with a human mesothelial cell monolayer or with the ECM proteins collagen IV, laminin-1, fibronectin, tenascin-C and vitronectin. Quantitation was achieved following staining of tumor cells with the calcein-AM fluorescent dye. We found that all four cell lines rapidly adhered to a mesothelial cell monolayer. This adhesion event was not inhibitable by anti-integrin and anti-CD44 antibodies. Following initial attachment, the SW480 and SW620 cells invaded the mesothelial cell monolayer more aggressively than HT29 and Co115 cells. All cell lines adhered to ECM proteins with each one exhibiting an individual adhesion pattern. Adhesion to matrix was completely integrin-dependent. When tested in an invasion assay, HT29 and Co115 cells crossed Matrigel-coated filters while SW480 and SW620 cells did not. This invasion was inhibited by anti-beta 1 integrin antibodies. Taken together, our results demonstrate that the initial colorectal tumor cell-mesothelial cell interaction occurs through an integrin-independent mechanism while adhesion to matrix proteins and invasion through Matrigel are integrin-dependent events. Furthermore, the different invasive capacity of SW480 and SW620 versus HT29 and Co115 cells upon interaction with a mesothelial cell monolayer or Matrigel suggests that these two invasion events may be mediated by distinct mechanisms.
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PMID:Role of integrins and evidence for two distinct mechanisms mediating human colorectal carcinoma cell interaction with peritoneal mesothelial cells and extracellular matrix. 917 5

Adhesion of blood leukocytes to the endothelium involves multiple steps including initial attachment (tethering), rolling, and firm arrest. Presentation of adhesion molecules on leukocyte microvilli can substantially enhance tethering. Localization of L-selectin to microvilli and of CD44 to the planar cell body have been shown to depend upon their transmembrane and cytoplasmic domains. We investigated the role of leukocyte integrin transmembrane and cytoplasmic domains in initiating adhesion under flow and in microvillous localization. Integrins alpha4beta7, alphaLbeta2, and alphaMbeta2 were heterologously expressed in K562 cells. alpha4beta7 initiated adhesion under flow and localized to microvilli, whereas beta2 integrins did not initiate adhesion and localized to the cell body. Chimeric integrins were produced by replacing the alpha4beta7 cytoplasmic and/or transmembrane domains with the homologous domains of alphaLbeta2 or alphaMbeta2. Unexpectedly, these chimeras efficiently mediated adhesion to the alpha4beta7 ligand mucosal addressin cell adhesion molecule-1 under flow and localized to microvilli. Therefore, differences between the transmembrane and cytoplasmic domains of alpha4 and beta2 integrins do not account for differences in ability to support attachment under flow or in membrane localization. Integrins alpha4beta1, alpha5beta1, alpha6Abeta1, alphavbeta3, and alphaEbeta7 also localized to microvilli. Transmembrane proteins known or suspected to associate with extracellular domains of microvillous integrins, including tetraspans and CD47, were concentrated on microvilli as well. These findings suggest that interactions between the extracellular domains of integrins and associated proteins could direct the assembly of multimolecular complexes on leukocyte microvilli.
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PMID:Presentation of integrins on leukocyte microvilli: a role for the extracellular domain in determining membrane localization. 933 57


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