[Effect of cyclosporin A on intracellular accumulation and efflux of drug in K562/DOX cells].
OBJECTIVE
To explore measures to overcome multidrug resistance of tumor cells.


METHODS
The effects of cyclosporin A (CsA) on drug sensitivity, intracellular drug accumulation and drug efflux in multidrug-resistant human leukemic cell line K562/DOX were studied by MTT colorimetric assay and spectrofluorimetry.


RESULTS
CsA enhanced the cytotoxicity of doxorubicin (DOX) to K562/DOX, and when CsA > or = 2microg/ml the sensitivity of K562/DOX to DOX increased significantly. The efflux of DOX markedly decreased when K562/DOX cells were incubated with 2microg/ml CsA, while CsA had no effect on efflux of DOX in K562 cells.


CONCLUSIONS
CsA could markedly decrease the efflux and enhance the intracellular accumulation of DOX in K562/DOX cells.
Meng
H
H
First Affiliated Hospital of Zhejiang Medical University, Hangzhou 310003.
Lin
X
X
Lin
M
M
D016572:Cyclosporine / Q000494:pharmacology*; D004317:Doxorubicin / Q000378:metabolism* / Q000494:pharmacology; D018432:Drug Resistance, Multiple / Q000187:drug effects; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D006801:Humans; D042541:Intracellular Space / Q000187:drug effects* / Q000378:metabolism*; D020014:K562 Cells
D004317:Doxorubicin; D016572:Cyclosporine