Fulltext

Effect of the modulation of the membrane lipid composition on the localization and function of P-glycoprotein in MDR1-MDCK cells

Kamau, Sarah ; Krämer, Stefanie ; Günthert, Maja ; Wunderli-Allenspach, Heidi

In: In Vitro Cellular & Developmental Biology - Animal, 2005, vol. 41, no. 7, p. 207-216

Add to personal list
    Title
    • Effect of the modulation of the membrane lipid composition on the localization and function of P-glycoprotein in MDR1-MDCK cells
    Author
    • Kamau, Sarah. Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurestrasse 190, CH-8057, Zurich, Switzerland
    • Krämer, Stefanie. Institute of Pharmaceutical Sciences, ETH Federal Institute of Technology, Wolfgang-Pauli-Strasse 10, CH-8093, Zurich, Switzerland
    • Günthert, Maja. Institute of Pharmaceutical Sciences, ETH Federal Institute of Technology, Wolfgang-Pauli-Strasse 10, CH-8093, Zurich, Switzerland
    • Wunderli-Allenspach, Heidi. Institute of Pharmaceutical Sciences, ETH Federal Institute of Technology, Wolfgang-Pauli-Strasse 10, CH-8093, Zurich, Switzerland
    Document Type
    • Postprint
    Language
    • English
    Published in
    • In Vitro Cellular & Developmental Biology - Animal, 2005, vol. 41, no. 7, p. 207-216. Springer-Verlag
    Other Version
    OAI-PMH Identifier
    • oai:doc.rero.ch:309655
    Summary
    Summary: Multidrug resistance (MDR) is a major obstacle in cancer therapy. It results from different mechanisms; among them is P-glycoprotein (P-gp)-mediated drug efflux out of cells. The mechanism of action remains elusive. The membrane lipid surrounding of P-gp, especially cholesterol, has been postulated to play an important role. To determine the effect of cholesterol depletion on P-gp, Madin Darby canine kidney (MDCK) cells, transfected with the mdr1 gene (MDR1-MDCK cells), were treated with methyl-β-cyclodextrin (MβCD). The localization and function of P-gp were analyzed using confocal laser scanning microscopy. Treatment with 100 mM MβCD did not affect viability but altered the structural appearance of the cells and abolished efflux of rhodamine 123, a P-gp substrate. The MβCD treatment released P-gp from intact cells into the supernatant and reduced the amount of P-gp in total membrane preparations. The P-gp was shifted from the raft fractions (1% Triton X-100, 4° C) to higher density fractions in MβCD-treated cells. The amount of cholesterol was significantly decreased in the raft fractions. Treatment of cells with 1-phenyl-2-decanoylamino-3-morpholino-1-propanol, a glucosylceramide synthase inhibitor, also led to a shift of P-gp to higher density fractions. These results show that removal of cholesterol modulates the membrane lipid composition, changes the localization of P-gp, and results in loss of P-gp function