Efflux of depsipeptide FK228 (FR901228, NSC-630176) is mediated by P-glycoprotein and multidrug resistance-associated protein 1.
Depsipeptide FK228 [(E)-(1S,4S,10S,21R)-7[(Z)-ethylideno]-4,21-diisopropyl-2-oxa-12,13-dithia-5,8,20,23-tetraazabicyclo[8,7,6]-tricos-16-ene-3,6,9,22-pentanone], a novel histone deacetylase (HDAC) inhibitor, previously was reported to be a P-glycoprotein (Pgp) substrate. We now expand the investigation to demonstrate that FK228 is a substrate for Pgp and multidrug resistance-associated protein 1 (MRP1). Transport of FK228 across the Caco-2 cell monolayer in apical to basolateral (AP-->BL) and basolateral to apical (BL-->AP) directions in the absence and presence of Pgp and MRP inhibitors were investigated. An in vitro uptake study in human red blood cells (RBCs) and a cytotoxicity assay in MRP1(-) HL60 and MRP1(+) HL60Adr cells were conducted to show that FK228 is an MRP1 substrate. An FK228-resistant cell line (HCT15R) was developed from HCT15 colon carcinoma and characterized using a 70-oligomer cDNA microarray, reverse transcription-polymerase chain reaction, Western blot analysis, histone acetyltransferase (HAT) and HDAC activity assays, and cytotoxicity assays. FK228 showed a nearly unidirectional flux across the Caco-2 cell monolayer, with the BL-->AP apparent permeability coefficient (P(app)) 32 times that of AP-->BL without apparent saturation. Pgp inhibition decreased the BL-->AP P(app) and increased the AP-->BL P(app). RBC showed a concentration-dependent uptake and saturable efflux of FK228. HL60Adr cells were 4-fold more resistant to FK228 than HL60 cells, and the resistance was reversed by MRP inhibition. Up-regulation of Pgp, but not changes of MRPs or HAT/HDAC enzymatic activities, was the major mechanism for the acquired FK228 resistance. These studies demonstrate that FK228 is a substrate for Pgp and MRP1, and reversible Pgp up-regulation is predominantly involved in FK228 resistance in vitro.
Xiao
Jim J
JJ
Division of Pharmaceutics, College of Pharmacy, The Ohio State Univeristy, Columbus, Ohio 43210, USA.
Foraker
Amy B
AB
Swaan
Peter W
PW
Liu
Shujun
S
Huang
Ying
Y
Dai
Zunyan
Z
Chen
Jiyun
J
Sadée
Wolfgang
W
Byrd
John
J
Marcucci
Guido
G
Chan
Kenneth K
KK
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D000465:Algorithms; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000378:metabolism*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D015153:Blotting, Western; D018938:Caco-2 Cells; D002460:Cell Line; D018076:DNA, Complementary / Q000096:biosynthesis / Q000235:genetics; D047630:Depsipeptides / Q000378:metabolism*; D004317:Doxorubicin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000378:metabolism*; D004912:Erythrocytes / Q000378:metabolism; D018922:HL-60 Cells; D056572:Histone Deacetylase Inhibitors; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D017239:Paclitaxel / Q000494:pharmacology
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D000972:Antineoplastic Agents, Phytogenic; D018076:DNA, Complementary; D047630:Depsipeptides; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D004317:Doxorubicin; C087123:romidepsin; D017239:Paclitaxel