[Effect of intracellular acidification on P-glycoprotein in drug-resistant K562/A02 cells].
The aim of this study was to investigate the effect of intracellular acidification on the P-gp in K562/A02 cells. Confocal laser microscope was used to determine the intracellular acidification. MTT assay was used to detect the cytotoxicity of intracellular acidification on K562 and K562/A02 cells. Flow cytometry was applied to measure the influence of intracellular acidification on the activity of P-gp. The P-gp expression at protein and mRNA levels were determined by Western blot and real-time RT-PCR respectively. The results indicated that intracellular acidification had no obvious cytotoxicity on K562 and K562/A02 cells. The function of P-gp in K562/A02 cells weakened along with decrease of intracellular acidification, the intracellular acidification significantly increased the accumulation of Rhodamine 123 (Rh 123) and suppressed the efflux of Rh 123 mediated by P-gp. The intracellular acidification also inhibited the expression of P-gp in K562/A02 cells at protein and mRNA levels which showed intracellular acidification with time-dependence. It is concluded that the intracellular acidification can inhibit the expression and function of P-gp in K562/A02 cells.
Lu
Ying
Y
National Key Laboratory of Experimental Hematology, Institute of Hematology & Blood Disease Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China.
Li
Qing-Hua
QH
Ma
Li
L
Li
Bin
B
Yuan
Wen-Su
WS
Ru
Yong-Xin
YX
Wang
Jian-Xiang
JX
Pang
Tian-Xiang
TX
D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D006801:Humans; D006863:Hydrogen-Ion Concentration; D020014:K562 Cells
C513055:ABCB1 protein, human; D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1