The matrix metalloproteinase-7 is involved in cellular senescence of human mammary epithelial cells [Elektronische Ressource] / von Catharina Bertram

The matrix metalloproteinase-7 is involved in cellular senescence of human mammary epithelial cells Von der naturwissenschaftlichen Fakultät der Gottfried Wilhelm Leibniz Universität Hannover zur Erlangung des Grades Doktorin der Naturwissenschaften Dr. rer. nat. genehmigte Dissertation von Dipl.-Biochem. Catharina Bertram geboren am 08.05.1982 in Göttingen 2009 Referent: Prof. Dr. rer. nat. Ralf Hass Koreferent: Prof. Dr. rer. nat. Walter Müller Tag der Promotion: 21.07.2009 Abstract Besides typical characteristics of cellular senescence such as cell cycle arrest and increased SA β-gal (senescence-associated β-galactosidase) activity, the aging process of primary human mammary epithelial cells (HMEC) was accompanied by significant alterations of the extracellular environment, involving cell-cell and cell-matrix interactions. Expression of the cell surface-associated glycoproteins CD24, CD44 and CD227 (MUC1) was significantly reduced upon senescence, whereas these proteins were overexpressed in MCF-7 breast cancer cells. Analysis of different matrix metalloproteinases (MMPs) revealed a significant down-regulation of latent and active MMP-7 in senescent HMEC in contrast to the unchanged protein levels of MMP-1, MMP-2 and MMP-9.