Different effects of metabolic inhibitors and cyclosporin A on daunorubicin transport in leukemia cells from patients with AML.
The objective of this study was to determine the role of transport proteins in daunorubicin (Dnr) accumulation and efflux in leukemia cells from 36 patients with acute myeloid leukemia (AML). Mononuclear cells were isolated and incubated with 1 microM Dnr with/without addition of 3 microM cyclosporin A (CyA) or metabolic inhibitors (MI). Cellular Dnr concentration in leukemia blast cells was measured with flow cytometry. After washing and reincubation of the cells in drug-free medium, Dnr efflux was followed with/without addition of CyA or MI. Levels of mRNA expression for mdr1, multidrug resistance associated protein (mrp) and lung resistance protein (lrp) were determined with reverse transcriptase-polymerase chain reaction (RT-PCR). MI enhanced cellular Dnr accumulation to a higher extent than CyA whereas CyA reduced Dnr efflux more efficiently than MI (P<0.001). There was a significant difference in Dnr accumulation between samples with low and high mdr1 mRNA levels but only in the presence of MI or CyA. Our results imply that other factors than P-glycoprotein (Pgp) are of major importance for in vitro Dnr accumulation in AML blasts and that the role of Pgp as a drug efflux pump is not conclusive.
Knaust
Eva
E
Clinical Pharmacology, Department of Medicine and Care, Faculty of Health Sciences, SE-581 85, Linköpings Universitet, Linköping, Sweden. eva.knaust@imv.liu.se
Porwit-MacDonald
Anna
A
Gruber
Astrid
A
Xu
Dawei
D
Peterson
Curt
C
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000502:physiology; D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D016572:Cyclosporine / Q000494:pharmacology*; D003630:Daunorubicin / Q000493:pharmacokinetics*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007461:Iodoacetates / Q000494:pharmacology; D007951:Leukemia, Myeloid / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics / Q000502:physiology; D009363:Neoplasm Proteins / Q000235:genetics / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D019810:Sodium Azide / Q000494:pharmacology; D020394:Vault Ribonucleoprotein Particles / Q000235:genetics / Q000502:physiology; D000099187:Major Vault Protein
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D002352:Carrier Proteins; D016572:Cyclosporine; D003630:Daunorubicin; D004791:Enzyme Inhibitors; D007461:Iodoacetates; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D019810:Sodium Azide; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein