Study of mifepristone on reversing multidrug resistance of leukemic cell line K562/A02.
- Author:
De-xiao KONG
1
;
Chun-yan CHEN
;
Fu-yu XU
;
Ji-hui JIA
Author Information
- Publication Type:Journal Article
- MeSH: ATP-Binding Cassette, Sub-Family B, Member 1; metabolism; Cell Proliferation; drug effects; Daunorubicin; pharmacokinetics; Doxorubicin; pharmacology; Drug Resistance, Multiple; drug effects; Drug Resistance, Neoplasm; drug effects; Glucosyltransferases; genetics; metabolism; Humans; K562 Cells; Mifepristone; pharmacology; RNA, Messenger; genetics; bcl-2-Associated X Protein; metabolism
- From: Chinese Journal of Hematology 2007;28(8):555-559
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVETo study whether progestogen antagonist mifepristone could reverse multidrug resistance of K562/A02 cells and its mechanisms.
METHODSMTT was used to study the proliferation of K562/A02 cells and sensitivity of K562/A02 cells to ADM after 72 hours treatment with mifepristone. Flow cytometry was used to assay the expression of P-glycoprotein and the mean fluorescent intensity of intracellular daunorubicin. The expressions of apoptosis related proteins (bcl-2, Bax and caspase-3) were assayed by immunohistochemistry and the glucosylceramide synthase mRNA expression by RT-PCR before and after mifepristone treatment.
RESULTSMTT assay revealed that 2.5, 5.0 and 10 micromol/L mifepristone did not affect the proliferation of K562/A02 cells, but enhanced the sensitivity of K562/A02 cells to ADM, by 1. 68-, 4.17- and 10.71- fold increase, respectively. Expression of P-gp in K562/A02 cells was (49.03 +/- 5.32)%, and was decreased to (28.60 +/- 2.13)% (P < 0.01) after 10 micromol/L mifepristone treatment for 72 hours. and intracellular DNR accumulation in K562/A02 was (61.07 +/- 8.61)%, and was increased to (92.72 +/- 3.48)% (P < 0.01). After 10 micromol/L mifepristone treatment, the expression of bcl-2 protein was decreased from (56 +/- 9)% to (37 +/- 6)% (P < 0.05), Bax and caspase-3 proteins was increased from (40 +/- 5)% to (87 +/- 10)% (P < 0.01), and from (36 +/- 7)% to (89 +/- 6)% (P < 0.01) respectively. RT-PCR analysis revealed that expression of glucosylceramide synthase mRNA was higher in K562/A02 than in K562 cells, whereas 10 micromol/L mifepristone significantly down-regulated its expression in K562/A02 cells.
CONCLUSIONMifepristone at 10 micromol/L could dose-dependently reverse the multidrug resistance of K562/A02 cells. The possible mechanisms are related with decreasing the expression of P-gp, regulating the expression of apoptosis related proteins and decreasing the expression of glucosylceramide synthase.