Upregulation of ABC transporters contributes to chemoresistance of sphingosine 1-phosphate lyase-deficient fibroblasts.
Sphingosine 1-phosphate (S1P) is an extra- and intracellular mediator that regulates cell growth, survival, migration, and adhesion in many cell types. S1P lyase is the enzyme that irreversibly cleaves S1P and thereby constitutes the ultimate step in sphingolipid catabolism. It has been reported previously that embryonic fibroblasts from S1P lyase-deficient mice (Sgpl1(-/-)-MEFs) are resistant to chemotherapy-induced apoptosis through upregulation of B cell lymphoma 2 (Bcl-2) and Bcl-2-like 1 (Bcl-xL). Here, we demonstrate that the transporter proteins Abcc1/MRP1, Abcb1/MDR1, Abca1, and spinster-2 are upregulated in Sgpl1(-/-)-MEFs. Furthermore, the cells efficiently sequestered the substrates of Abcc1 and Abcb1, fluo-4 and doxorubicin, in subcellular compartments. In line with this, Abcb1 was localized mainly at intracellular vesicular structures. After 16 h of incubation, wild-type MEFs had small apoptotic nuclei containing doxorubicin, whereas the nuclei of Sgpl1(-/-)-MEFs appeared unchanged and free of doxorubicin. A combined treatment with the inhibitors of Abcb1 and Abcc1, zosuquidar and MK571, respectively, reversed the compartmentalization of doxorubicin and rendered the cells sensitive to doxorubicin-induced apoptosis. It is concluded that upregulation of multidrug resistance transporters contributes to the chemoresistance of S1P lyase-deficient MEFs.
Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität, Frankfurt am Main, Germany.
Katja
K
Ihlefeld
Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität, Frankfurt am Main, Germany.
Hans
H
Vienken
Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität, Frankfurt am Main, Germany.
Ralf Frederik
RF
Claas
Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität, Frankfurt am Main, Germany.
Kira
K
Blankenbach
Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität, Frankfurt am Main, Germany.
Agnes
A
Rudowski
Institut für Pharmakologie, Universitätsklinikum Essen, Essen, Germany.
Michael
M
ter Braak
Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität, Frankfurt am Main, Germany.
Alexander
A
Koch
Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven, Leuven, Belgium.
Paul P
PP
Van Veldhoven
Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität, Frankfurt am Main, Germany.
Josef
J
Pfeilschifter
Institut für Allgemeine Pharmakologie und Toxikologie, Klinikum der Goethe-Universität, Frankfurt am Main, Germany.
Dagmar
D
Meyer zu Heringdorf
D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000446:Aldehyde-Lyases / Q000172:deficiency*; D000814:Aniline Compounds / Q000494:pharmacology; D000818:Animals; D004317:Doxorubicin / Q000494:pharmacology; D019008:Drug Resistance, Neoplasm; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D021381:Protein Transport / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects*; D014966:Xanthenes / Q000494:pharmacology
D018528:ATP-Binding Cassette Transporters; D000814:Aniline Compounds; C409648:Fluo 4; D014966:Xanthenes; D004317:Doxorubicin; D000446:Aldehyde-Lyases; C022649:sphingosine 1-phosphate lyase (aldolase)
apoptosis; cancer; fluorescence microscopy; lysophospholipid; sphingolipids; transport