title: [Study on the relationship between [Ca2+]i and the MDR formation in K562/A02 cells].
abstract: To explore the relationship of multidrug resistance formation in K562/A02 cells with the intracellular concentration of [Ca(2+)]i, the cytotoxicities of daunorubicin (DNR) were assayed by MTT method, the variations of [Ca(2+)]i of K562 cells and K562/A02 cells after treatment of Tet, DRL and DNR alone or in combination were detected by using Fura-2/AM. The results showed as follows: (1) The cytotoxicities of DNR to cell line K562/A02 were enhanced by 1 micro mol/L Tet or 5 micro mol/L DRL. Their IC(50) was (7.28 +/- 2.06) micro g/ml and (7.58 +/- 3.44) micro g/ml; multiple of their reversal effect was 2.94 and 2.82, but IC(50) of combined Tet and DRL was (1.66 +/- 0.41) micro g/ml. Its reverse effect distinctly increased by 12.9 times. (2) The [Ca(2+)]i in K562/A02 cells were higher than that in K562 cells. (3) One micro mol/L Tet and 5 micro mol/L DRL alone increased the [Ca(2+)]i in K562/A02 cells time-dependently and there was antagonism when both were used. It is concluded that high [Ca(2+)]i is supposed to be a reason of MDR in K562/A02 cells, the action of resistance modifying agents (RMA) in MDR reverse course, however, needs further research.
authors.affiliation: Department of Hematology, Zhongda Hospotal, Medical College of Southeast University, Nanjing 210009, China. cba8888@hotmail.com
authors.forename: Bao-An
authors.initials: BA
authors.lastname: Chen
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhou
authors.forename: Jian
authors.initials: J
authors.lastname: Cheng
authors.forename: Ying
authors.initials: Y
authors.lastname: Dong
authors.forename: Xi-Jun
authors.initials: XJ
authors.lastname: Qian
authors.forename: Min
authors.initials: M
authors.lastname: Sheng
authors.forename: Ting
authors.initials: T
authors.lastname: Wang
authors.forename: Feng
authors.initials: F
authors.lastname: Gao
mesh_terms: D000470:Alkaloids / Q000494:pharmacology; D044182:Benzylisoquinolines / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D003630:Daunorubicin / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D006801:Humans; D020014:K562 Cells; D013629:Tamoxifen / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D044182:Benzylisoquinolines; D013629:Tamoxifen; C038345:droloxifene; C009438:tetrandrine; D002118:Calcium; D003630:Daunorubicin