title: Dynamic interplay between breast cancer cells and normal endothelium mediates the expression of matrix macromolecules, proteasome activity and functional properties of endothelial cells.
abstract: BACKGROUND
  Breast cancer-endothelium interactions provide regulatory signals facilitating tumor progression. The endothelial cells have so far been mainly viewed in the context of tumor perfusion and relatively little is known regarding the effects of such paracrine interactions on the expression of extracellular matrix (ECM), proteasome activity and properties of endothelial cells.
  
  
  METHODS
  To address the effects of breast cancer cell (BCC) lines MDA-MB-231 and MCF-7 on the endothelial cells, two cell culture models were utilized; one involves endothelial cell culture in the presence of BCCs-derived conditioned media (CM) and the other co-culture of both cell populations in a Transwell system. Real-time PCR was utilized to evaluate gene expression, an immunofluorescence assay for proteasome activity, and functional assays (migration, adhesion and invasion) and immunofluorescence microscopy for cell integrity and properties.
  
  
  RESULTS
  BCC-CM decreases the cell migration of HUVEC. Adhesion and invasion of BCCs are favored by HUVEC and HUVEC-CM. HA levels and the expression of CD44 and HA synthase-2 by HUVEC are substantially upregulated in both cell culture approaches. Adhesion molecules, ICAM-1 and VCAM-1, are also highly upregulated, whereas MT1-MMP and MMP-2 expressions are significantly downregulated in both culture systems. Notably, the expression and activity of the proteasome β5 subunit are increased, especially by the action of MDA-MB-231-CM on HUVEC.
  
  
  CONCLUSIONS
  BCCs significantly alter the expression of matrix macromolecules, proteasome activity and functional properties of endothelial cells. Deep understanding of such paracrine interactions will help to design novel drugs targeting breast cancer at the ECM level. This article is part of a Special Issue entitled Matrix-mediated cell behaviour and properties.
authors.affiliation: Biochemistry, Biochemical Analysis & Matrix Pathobiology Res. Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, 26110 Patras, Greece; Foundation for Research and Technology, Institute of Chemical Engineering Sciences (FORTH/ICE-HT), 26500 Patras, Greece.
authors.forename: Ch
authors.initials: Ch
authors.lastname: Gialeli
authors.affiliation: Department of Surgery and Morphological Sciences, University of Insubria, Varese, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Viola
authors.affiliation: Biochemistry, Biochemical Analysis & Matrix Pathobiology Res. Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, 26110 Patras, Greece; Foundation for Research and Technology, Institute of Chemical Engineering Sciences (FORTH/ICE-HT), 26500 Patras, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Barbouri
authors.affiliation: Laboratory of Cell Proliferation and Ageing, Institute of Biology, National Center of Scientific Research "Demokritos", Athens, Greece.
authors.forename: D
authors.initials: D
authors.lastname: Kletsas
authors.affiliation: Department of Surgery and Morphological Sciences, University of Insubria, Varese, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Passi
authors.affiliation: Biochemistry, Biochemical Analysis & Matrix Pathobiology Res. Group, Laboratory of Biochemistry, Department of Chemistry, University of Patras, 26110 Patras, Greece; Foundation for Research and Technology, Institute of Chemical Engineering Sciences (FORTH/ICE-HT), 26500 Patras, Greece. Electronic address: n.k.karamanos@upatras.gr.
authors.forename: N K
authors.initials: NK
authors.lastname: Karamanos
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D002448:Cell Adhesion / Q000187:drug effects; D002450:Cell Communication / Q000187:drug effects; D045744:Cell Line, Tumor; D017077:Culture Media, Conditioned / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D004727:Endothelium / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D014453:Glucuronosyltransferase / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000378:metabolism; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D008954:Models, Biological; D009361:Neoplasm Invasiveness; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D017077:Culture Media, Conditioned; D018960:Hyaluronan Receptors; D019010:Vascular Cell Adhesion Molecule-1; D018799:Intercellular Adhesion Molecule-1; D006820:Hyaluronic Acid; D014453:Glucuronosyltransferase; C101754:HAS2 protein, human; D000076002:Hyaluronan Synthases; D020778:Matrix Metalloproteinase 2; D053511:Matrix Metalloproteinase 14; D046988:Proteasome Endopeptidase Complex
keywords: Breast cancer cell; Cell functional properties; Endothelium; Extracellular matrix; Hyaluronan; Proteosome