MDR1 gene overexpression confers resistance to imatinib mesylate in leukemia cell line models
MDR1 gene overexpression confers resistance to imatinib mesylate in leukemia cell line models
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DOI：
10.1182/blood.v101.6.2368
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发表时间：
2003-03-15
期刊：
影响因子：
20.3
通讯作者：
Melo, JV
中科院分区：
文献类型：
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作者：
Mahon, FX;Belloc, F;Melo, JV
编码P-糖蛋白(Pgp)的多药耐药(MDR1)基因的不适当表达经常与不同化疗药物的耐药有关。我们之前已经建立了对酪氨酸激酶抑制剂甲磺酸伊马替尼(STI571)耐药的慢性髓系白血病(Civil)细胞株，其中一株(LAMA84-r)不仅显示出BCR-Abl蛋白的过度表达，而且还显示出Pgp的过度表达。在目前的研究中，我们研究了在其他细胞株中仅过度表达Pgp的这种现象。因此，K562/DOX细胞系由于mdr1基因过表达而被描述为对阿霉素耐药的细胞，在1um伊马替尼存在下持续生长，但如果在伊马替尼处理的培养物中加入Pgp泵调节剂维拉帕米或PSC833，则在4~5天内死亡。MTS(3-(4，5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium)assay细胞增殖分析证实K562/DOX对伊马替尼的差异敏感性，维拉帕米或PSC833也逆转了这种敏感性。流式细胞仪检测细胞内总酪氨酸含量显示，K562/DOX、K562/DOX+维拉帕米、K562/DOX+维拉帕米作用2小时后，K562/DOX、K562/DOX+维拉帕米、K562细胞蛋白酪氨酸磷酸化的半数抑制浓度(IC50)分别为15、10、5um。逆转录病毒介导的携带mdr1基因的bcr-abl(+)AR230细胞株降低了对伊马替尼的敏感性，这种作用也被维拉帕米逆转。MDR过表达在临床对伊马替尼耐药中的可能作用仍有待确定。因此，我们确认应将伊马替尼添加到可能受到多药耐药现象影响的广泛药物清单中。
Inappropriate expression of the multidrug resistance (MDR1) gene encoding the P-glycoprotein (Pgp) has been frequently implicated in resistance to different chemotherapeutic drugs. We have previously generated chronic myeloid leukemia (CIVIL) cell lines resistant to the tyrosine kinase inhibitor imatinib mesylate (STI571), and one line (LAMA84-r) showed overexpression not only of the Bcr-Abl protein but also of Pgp. In the present study, we investigated this phenomenon in other cell lines overexpressing exclusively Pgp. Thus, cells from the K562/DOX line, described as resistant to doxorubicin due to MDR1 gene overexpression, grew continuously in the presence of 1 muM imatinib, but died in 4 to 5 days if the Pgp pump modulators verapamil or PSC833 were added to the imatinib-treated culture. Analysis of cell proliferation by the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium)assay confirmed the differential sensitivity of K562/DOX to imatinib, which was also reversed by verapamil or PSC833. Flow cytometric analysis of the total phosphotyrosine content by intracytoplasmic staining after a 2-hour incubation with escalating doses of imatinib showed that the inhibitory concentrations of 50% (IC50) for inhibition of cellular protein tyrosine phosphorylation were 15,10, and 5 muM for K562/DOX, K562/DOX plus verapamil, and K562, respectively. Retroviral-mediated transfection of the BCR-ABL(+) AR230 cell line with the MDR1 gene decreased its sensitivity to imatinib, an effect that was also reversed by verapamil. The possible role of MDR overexpression in clinical resistance to imatinib remains to be defined. We therefore confirm that imatinib should be added to the extensive list of drugs that can be affected by the MDR phenomenon.