[A study of the GSH contents, GST activity and the expression of GST isoenzyme and MRP in drug-resistant leukemic cell lines].
OBJECTIVE
To understand the non-mdr1 mechanism in multidrug-resistant leukemic cell lines.


METHODS
GSH contents and GST activity were measured by biochemical methods, the expression of GST isoenzyme alpha, pi, mu and MRP mRNAs were examined by Northern blot, and the expression of GST alpha, pi, mu proteins were examined by Western blot in sensitive HL-60, K562 and resistant K562/H20, HL-60/Adr, K562/VCR leukemic cell lines, respectively.


RESULTS
Compared with K562/S, GSH contents and GST activities were increased in K562/H20 and K562/VCR, and GST alpha, pi or GST mu, pi were overexpressed in K562/H20 or K562/VCR, while there was no difference of GSH contents, GST activities or GST isoenzyme expressions between HL-60/Adr and HL-60/S. The increased expressions of MRP mRNA were revealed in the three resistant cell lines.


CONCLUSIONS
GSH, GST and MRP involved in the drug resistance of K562/H20 and K562/VCR, while only MRP associated with drug resistance of HL-60/Adr.
Department of Hematology, Huashan Hospital, Shanghai Medical University, Shanghai 200040.
R
R
Xia
G
G
Lin
Y
Y
Li
D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis* / Q000235:genetics; D005978:Glutathione / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism*; D018922:HL-60 Cells / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes; D020014:K562 Cells / Q000378:metabolism; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics
D018528:ATP-Binding Cassette Transporters; D005978:Glutathione; D005982:Glutathione Transferase; D007527:Isoenzymes; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D012333:RNA, Messenger