Ceramide and glucosylceramide upregulate expression of the multidrug resistance gene MDR1 in cancer cells.
In the present study we used human breast cancer cell lines to assess the influence of ceramide and glucosylceramide (GC) on expression of MDR1, the multidrug resistance gene that codes for P-glycoprotein (P-gp), because GC has been shown to be a substrate for P-gp. Acute exposure (72 h) to C8-ceramide (5 microg/ml culture medium), a cell-permeable ceramide, increased MDR1 mRNA levels by 3- and 5-fold in T47D and in MDA-MB-435 cells, respectively. Acute exposure of MCF-7 and MDA-MB-231 cells to C8-GC (10 microg/ml culture medium), a cell-permeable analog of GC, increased MDR1 expression by 2- and 4- fold, respectively. Chronic exposure of MDA-MB-231 cells to C8-ceramide for extended periods enhanced MDR1 mRNA levels 45- and 390-fold at passages 12 and 22, respectively, and also elicited expression of P-gp. High-passage C8-ceramide-grown MDA-MB-231 (MDA-MB-231/C8cer) cells were more resistant to doxorubicin and paclitaxel. Incubation with [1-(14)C]C6-ceramide showed that cells converted short-chain ceramide into GC, lactosylceramide, and sphingomyelin. When challenged with 5 mug/ml [1-(14)C]C6-ceramide, MDA-MB-231, MDA-MB-435, MCF-7, and T47D cells took up 31, 17, 21, and 13%, respectively, and converted 82, 58, 62, and 58% of that to short-chain GC. Exposing cells to the GCS inhibitor, ethylenedioxy-P4, a substituted analog of 1-phenyl-2-hexadecanoylamino-3-pyrrolidino-1-propanol, prevented ceramide's enhancement of MDR1 expression. These experiments show that high levels of ceramide and GC enhance expression of the multidrug resistance phenotype in cancer cells. Therefore, ceramide's role as a messenger of cytotoxic response might be linked to the multidrug resistance pathway.
John Wayne Cancer Institute at Saint John's Health Center, Department of Experimental Therapeutics, Santa Monica, CA 90404, USA.
Valérie
V
Gouazé-Andersson
Jing Y
JY
Yu
Adam J
AJ
Kreitenberg
Alicja
A
Bielawska
Armando E
AE
Giuliano
Myles C
MC
Cabot
D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001943:Breast Neoplasms / Q000378:metabolism; D045744:Cell Line, Tumor / Q000502:physiology*; D002518:Ceramides / Q000737:chemistry / Q000378:metabolism*; D018432:Drug Resistance, Multiple / Q000502:physiology; D019008:Drug Resistance, Neoplasm / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation; D005963:Glucosylceramides / Q000737:chemistry / Q000378:metabolism*; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D015854:Up-Regulation
C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D002518:Ceramides; D005963:Glucosylceramides; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase