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 cells to components of the extracellular matrix has been shown to be critical in normal lung development, particularly during the pseudoglandular stage, when conducting airways are forming through a process of branching morphogenesis. Expression of factors that inhibit cellular adhesion might also modulate branching morphogenesis. SPARC is a secreted glycoprotein that exhibits antiadhesive effects on cultured cells and is widely expressed in embryonic tissues. In this report, we examine the distribution of SPARC in fetal rat lung during development and its effect on the process of branching morphogenesis. Immunohistochemistry and in situ hybridization studies revealed that SPARC was present in the airway epithelial cells during the pseudoglandular stage of lung development, and in blood vessels and smooth muscle cells associated with airways during the canalicular and saccular stages of development. We used an in vitro model of rat lung branching morphogenesis to examine airway branching in the presence of: a) a neutralizing anti-SPARC antibody; or b) a synthetic peptide from a region of SPARC that, like the native protein, perturbs cell adhesion and diminishes the synthesis of fibronectin and thrombospondin 1. Lungs cultured in the presence of either reagent exhibited diminished branching and an abnormal morphology that was characterized in part by dilated airways. These findings implicate SPARC in the development of the airways.
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PMID:SPARC participates in the branching morphogenesis of developing fetal rat lung. 765 84

We previously showed that thrombospondin 1 (TSP-1) upregulates the plasminogen/plasmin system and promotes breast tumor cell invasion. Preliminary data from our laboratory using neutralizing antibodies suggested that the upregulation in breast tumor cell invasion seen in response to TSP-1 involved the urokinase plasminogen activator receptor (uPAR). To confirm these findings in MDA-MB-231 breast cancer cells, we developed three other strategies to study the role of uPAR in tumor cell adhesion and TSP-1-mediated tumor cell invasion: (a) enzymatic cleavage of uPAR with glycosylphosphatidylinositol-specific phospholipase C; (b) inhibition at the mRNA level with a uPAR antisense construct (cells named LKAS-MDA); (c) inhibition of plasminogen binding with the lysine analogue epsilon-aminocaproic acid. Adhesion to laminin and type I and type IV collagen with and without the addition of epsilon-aminocaproic acid was studied. Tumor cell invasion was studied in a modified Boyden chamber collagen invasion assay. Antisense uPAR inhibition decreased uPAR expression by 48-66% and cell-associated urokinase plasminogen activator (uPA) by 30-68%. Additionally, antisense uPAR inhibition induced a 68-70% reduction in uPA and plasmin activities. Antisense uPAR transfection increased tumor cell adhesion by 46-53%. A similar effect was observed in epsilon-aminocaproic acid-treated MDA-MB-231 cells. TSP-1-mediated tumor cell invasion was almost completely inhibited by either antisense uPAR inhibition or treatment with phospholipase C or epsilon-aminocaproic acid. We conclude that uPAR plays a crucial role in the regulation of tumor cell adhesion and TSP-1-mediated tumor cell invasion.
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PMID:Role of urokinase plasminogen activator receptor in thrombospondin 1-mediated tumor cell invasion. 1009 Aug 48