ATP-Dependent Efflux of CPT-11 and SN-38 by the Multidrug Resistance Protein (MRP) and Its Inhibition by PAK-104P
- Zhe-Sheng Chen1,
- Tatsuhiko Furukawa1,
- Tomoyuki Sumizawa1,
- Kenji Ono2,
- Kazumitsu Ueda3,
- Kiyotomo Seto4 and
- Shin-Ichi Akiyama1
- 1Department of Cancer Chemotherapy, Institute for Cancer Research, Faculty of Medicine, Kagoshima University, Kagoshima, Japan (Z-S.C., T.F., T.S., S.A.); 2Experimental Technology Research Center, Tokyo Research and Development Center, Daiichi Pharmaceutical Co., Ltd., Tokyo, Japan (K.O.); 3Laboratory of Biochemistry, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan (K.U.); and 4Research Planning Department, Pharmaceutical Division, Nissan Chemical Industries, Ltd., Tokyo, Japan (K.S.)
Abstract
Non-P-glycoprotein-mediated multidrug-resistant C-A120 cells that overexpressed multidrug resistance protein (MRP) were 10.8- and 29.6-fold more resistant to 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin (CPT-11) and SN-38, respectively, than parental KB-3-1 cells. To see whether MRP is involved in CPT-11 and SN-38 resistance,MRP cDNA was transfected into KB-3-1 cells. The transfectant, KB/MRP, which overexpressed MRP, was resistant to both CPT-11 and SN-38. 2-[4-Diphenylmethyl)-1-piperazinyl]ethyl-5-(trans-4,6-dimethyl-1,3,2-dioxaphosphorinan-2-yl)-2,6-dimethyl-4-(3-nitrophenyl)-3-pyridinecarboxylate P-oxide (PAK-104P) and MK571, which reversed drug resistance in MRP overexpressing multidrug-resistant cells, significantly increased the sensitivity of C-A120 and KB/MRP cells, but not of KB-3-1 cells, to CPT-11 and SN-38. The accumulation of both CPT-11 and SN-38 in C-A120 and KB/MRP cells was lower than that in KB-3-1 cells. The treatment with 10 μM PAK-104P increased the accumulation of CPT-11 and SN-38 in C-A120 and KB/MRP cells to a level similar to that found in KB-3-1 cells. The ATP-dependent efflux of CPT-11 and SN-38 from C-A120 and KB/MRP cells was inhibited by PAK-104P. DNA topoisomerase I expression, activity, and sensitivity to SN-38 were similar in the three cell lines. Furthermore, the conversion of CPT-11 to SN-38 in KB-3-1 and C-A120 cell lines was similar. These findings suggest that MRP transports CPT-11 and SN-38 and is involved in resistance to CPT-11 and SN-38 and that PAK-104P reverses the resistance to CPT-11 and SN-38 in tumors that overexpress MRP.
Footnotes
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Send reprint requests to: Dr. Shin-Ichi Akiyama, Department of Cancer Chemotherapy, Institute for Cancer Research, Faculty of Medicine, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890, Japan. E-mail:akiyamas{at}khosp2.kufm.kagoshima-u.ac.jp
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This work was supported by grants from the Ministry of Education, Science and Culture; the Ministry of Health and Welfare, Japan; and the Japan Society for the Promotion of Science.
- Abbreviations:
- CPT
- camptothecin
- CPT-11
- 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxycamptothecin
- SN-38
- 7-ethyl-10-hydroxy camptothecin
- SN38-G
- SN-38 glucuronide
- topo
- DNA topoisomerase
- ADM
- adriamycin
- VCR
- vincristine
- MRP
- multidrug resistance protein
- MDR
- multidrug resistance
- cMOAT
- canalicular multispecific organic anion transporter
- P-gp
- P-glycoprotein
- LTC4
- leukotriene C4
- BSO
- buthionine sulfoximine
- MEM
- minimal essential medium
- MTT
- 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide
- GST
- glutathione S-transferase
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- Received December 2, 1998.
- Accepted February 22, 1999.
- The American Society for Pharmacology and Experimental Therapeutics
