[Establishment of an imatinib resistant cell line K562/G01 and its characterization].
OBJECTIVE
To establish a BCR/ABL+ cell line with resistance to imatinib, and investigate the possible mechanisms of the acquired resistance.


METHODS
K562 cells were cultured in gradually increased concentrations of imatinib over a period of several months to generate their resistance line. MTT assay, RT-PCR, Western blotting, and FISH were used to study the possible molecular mechanisms of the resistance.


RESULTS
A resistant cell line, K562/G01, was established with 15.2 +/- 3.0-fold resistant to imatinib as compared with that of the parental sensitive cell line. The resistant cell line also had the cross-resistance to a broad spectrum of other anticancer agents excepting for DOX. There was no difference between the two cell lines in terms of the cell morphology, proliferation doubling time, and fraction distribution of cell cycle. K562/G01 cells showed increased levels of BCR/ABL, mdr1 mRNA and their coding proteins and the increased tyrosine kinase activity. No point mutation in the BCR/ABL ATP-binding site was detected while the copies of BCR/ABL fusion gene were increased in K562/G01 cells.


CONCLUSIONS
An imatinib-resistant human leukemia cell line, K562/G01, was established. The mechanisms of resistance of K562/G01 cells to imatinib involved increased expression of BCR/ABL and mdr1/P-gp, amplification of BCR/ABL fusion gene, and increased activity of BCR/ABL.
State Key Laboratory of Experimental Hematology, Institute of Hematology, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300020, China.
Jing
J
Qi
Hui
H
Peng
Zhen-Lun
ZL
Gu
Zhong-Qin
ZQ
Liang
Chun-Zheng
CZ
Yang
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology*; D001549:Benzamides; D019008:Drug Resistance, Neoplasm; D004354:Drug Screening Assays, Antitumor; D016044:Fusion Proteins, bcr-abl / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000068877:Imatinib Mesylate; D020014:K562 Cells / Q000187:drug effects* / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate; D016044:Fusion Proteins, bcr-abl