Open AccessReversal of the resistance to STI571 in human chronic myelogenous leukemia K562 cells
Author(s) -
Mukai Motoi,
Che XiaoFang,
Furukawa Tatsuhiko,
Sumizawa Tomoyuki,
Aoki Shunji,
Ren XiaoQin,
Haraguchi Misako,
Sugimoto Yoshikazu,
Kobayashi Motomasa,
Takamatsu Hideo,
Akiyama Shinichi
Publication year - 2003
Publication title -
cancer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.035
H-Index - 141
eISSN - 1349-7006
pISSN - 1347-9032
DOI - 10.1111/j.1349-7006.2003.tb01482.x
Subject(s) - k562 cells , vincristine , chronic myelogenous leukemia , multiple drug resistance , pharmacology , biology , imatinib mesylate , leukemia , cancer research , etoposide , microbiology and biotechnology , drug resistance , immunology , chemotherapy , imatinib , genetics , myeloid leukemia , cyclophosphamide
STI571, an Abl‐specific tyrosine kinase inhibitor, selectively kills Bcr‐Abl‐containing cells in vitro and in vivo . However, some chronic myelogenous leukemia (CML) cell lines are resistant to STI571. We evaluated whether STI571 interacts with P‐glycopro‐tein (P‐gp) and multidrug resistance protein 1 (MRP1), and examined the effect of agents that reverse multidrug resistance (MDR) on the resistance to SI571 in MDR cells. STI571 inhibited the [ 125 l]azidoagosterol A‐photolabeling of P‐gp, but not that of MRP1. K562/MDR cells that overexpress P‐gp were 3.67 times more resistant to STI571 than the parental Philadelphia‐chromosome‐positive (Ph+) CML K562 cells, and this resistance was most effectively reversed by cepharanthine among the tested reversing agents. The concentration of STI571 required to completely inhibit tyrosine phosphorylation in K562/MDR cells was about 3 times higher than that in K562 cells, and cepharanthine abolished the difference. In KB‐G2 cells that overexpress P‐gp, but not Bcr‐Abl, 2.5 μM STI571 partly reversed the resistance to vincristine (VCR), paclitaxel, etoposide (VP‐16) and actinomycin D (ACD) but not to Adriamycin (ADM) or colchicine. STI571 increased the accumulation of VCR, but not that of ADM in KB‐G2 cells. STI571 did not reverse resistance to any agent in KB/MRP cells that overexpress MRP1. These findings suggest that STI571 is a substrate for P‐gp, but is less efficiently transported by P‐gp than VCR, and STI571 is not a substrate for MRP1. Among the tested reversing agents that interact with P‐gp, cepharanthine was the most effective agent for the reversal of the resistance to STI571 in K562/ MDR cells. Furthermore, STI571 itself was a potent reversing agent for MDR in P‐gp‐expressing KB‐G2 cells.